Market of Olive Residues for Energy - European Commission · 2014-08-11 · 5 1. Olive Oil...

1

Regional Energy Agency of

Central Macedonia

Market of Olive Residues for Energy

2

Work Package 3: Analysis of Local Situations + SWOT analyses+ Possible Trends

Deliverable 3.1:

One joint report for the 5 Regional “state of the art” reports from each

involved area describing the current olive-milling residues market (with a

focus on energy uses.

Leader of WP3: Regional Energy Agency of Central Macedonia (REACM) -

ANATOLIKI S.A.

Partners Involved: ARE Liguria-Italy, UC Liguria-Italy, AGENER-Spain, IPTPO-Croatia, UP ZRS-Slovenia

Date: July 2008

3

1. Olive Oil Extraction Process and By-Products (solid olive oil residues). .................................. 5

2. Pomace Oil Extraction Process and By-Products (pomace oil solid residues). ......................... 9

3. Olive oil and solid residues production in Spain, Italy, Greece, Slovenia & Croatia ................ 18

4. Energy Exploitation Methods .............................................................................................. 23

6. The current supply chains and the end-uses of solid residues in each region. ....................... 29

7. National and Regional policy aspects .................................................................................. 42

8. Technological Equipment & Costs ....................................................................................... 48

9. Annex ................................................................................................................................ 64

10. References ....................................................................................................................... 65

4

With more than 4.5 million hectares under cultivation, it is the second-most important agro-food sector in Europe. The production residues of olive and olive oil production are utilised as solid biomass fuel. The estimated amount of residues is about 1.5 million tons, including stones/pits and exhausted olive pomace.

The raw material is the so-called olive pomace. The olive pomace is a by-product of the olive oil production process and constitutes a mixture of olive pits, olive pulp and the water added in the olive mills. The moisture content is approximately 40-70-% depending on the olive oil extraction process. The amount of raw material depends on climate conditions, which determine the annual production period (8 to 9 months/year).

The production of olive oil begins with the picking of olives, continues with their transport and ends up with their processing in olive mills. After harvesting, any remaining leaves are removed; the olives are washed, and are ground into a pulp using a revolving mill, usually constructed with stainless steel or granite. The entire olive, including the pit, is pressed until it becomes a paste, which is then whipped, adding water. Next comes the phase to separate solid from liquid, either by the traditional process, or by a continuous system (centrifuge): 3-phase process or 2-phase process.

Olive mill technology generates a variety of wastes both solid and liquid. Solid wastes are generated also in the olive groves during pruning of olive trees. In this category of wastes are also included: leaves and small branches, the olives pits and the remained pomace resultant from olive oil extraction. Leaves can be used as animal feed, as fertilizer or in the production of compost, while small branches, pits and dried olive pomace also can be used for energy production. Liquid wastes are known as Olive Mill Waste Water (OMWW) and are used in some cases as additives for the manufacture of cosmetics and also for biogas, since substantial amounts of unrecoverable oil and fine residues of pomace remain in the particles of OMWW.

Figure 1:Olive pomace (virgin) Figure 2: Olive Pits

The scope of this report is to study the energy exploitation potential of solid wastes produced

during olive oil extraction, as well as to analyse the regional situation in the five regions below:

1. The region of Liguria in Italy. 2. The region of Jaen in Spain. 3. The region of Chania in the island of Crete, Greece. 4. The region of Istria in Croatia. 5. The region of Istria in Slovenia.

5

1. Olive Oil Extraction Process and By-Products (solid olive oil

residues).

Four to ten kilos of olives are needed to produce just 1 litre of olive oil. The olive tree begins to produce olives between the ages of 5 to 10 years, reaching maturity at about 20 years. After 100 to 150 years, its production begins to decline. The age of the tree influences only the quantity produced, not the quality. The

harvesting can be done by hand hitting the tree with a flexible pole so that the olives fall into canvas covers placed on the ground or by means of mechanical vibrations.

Some olive varieties may be picked in October when they are still green, while other varieties may be left until February when they are at the peak of ripeness and bursting with oil. Olives are usually pressed within 24 hours if the weather is hot. If the weather is cooler, the pressing may occur within 72 hours of harvesting.

Until about 30 years ago, almost all olive oil was obtained through pressing. In the 70s, the mills gradually abandoned the traditional olive pressing process for economical reasons. Nowadays the traditional method is only used for processing small quantities of ecological olive oil. The alternative method is the continuous system works by means of the centrifugation of the beaten olive paste, producing three products: oil, pomace and residual water, just like the pressing system. During the 90s, there was a major change in the raw material arriving at the olive pomace oil extractors. This was due to the fact that a large number of Spanish mills changed the olive oil continuous extraction equipment, converting from the three phase to the two phase system in order to optimize extraction costs and prevent the production of a highly polluting residual wastewater.

At present, three types of olive pomace can be considered, depending on the extraction system used on the olives (shown in Figure 3):

Figure 3: Flow scheme of the 3 different olive oil production processes, a) traditional process, b) 3-phase

decanter process, c) 2-phase decanter process.

Source: TDC OLIVE “By product Reusing”

6

• The Traditional process”, also known as traditional method. The ground paste is placed between pressing mats and is subject to pressure, to expel the oil mix (mixture of oil and water). The mixture is then poured into a vat or holding tank. This is allowed to rest so that gravity and different densities come into play, separating the oil from the water.

• The “3-phase process”. The process based on a 3-phase decanter: 1 litre of water is added per kilo of paste; it is then added to a horizontal centrifugal machine, where the solid is separated from the oil must. The must is then passed on to a vertical centrifugal machine, where the oil is separated from the vegetable water.

• The “2-phase process”. The process based on a 2-phase decanter: Same process as above, but instead of adding water for the horizontal centrifugation, the vegetable water is recycled.

The main differences between the extracted raw materials are due to water content. Two-phase pomace has moisture approximately 50-70% and contains a certain amount of sugars as a result of the presence of vegetation water, while traditional pomace has a moisture content of between 25- 30% in the pressing system, and 45-60% in 3-phase centrifugal systems.

Figure 4: Example of an olive oil processing line

In Spain the most widely used process is the “2-phase”. In Italy both “3-phase” and traditional methods are used, while in Greece “3-phase” is more common. In Slovenia the only method not used is the “3-phase” and finally in Croatia all methods are used.

Comparing the three processes:

• The main disadvantage of the “3-phase process” is the huge amount of water needed and consequently the production of vegetable water.

• The stream of the milled olives in “2-phase process” is separated in a 2-phase decanter. This system enables reduced fresh water consumption and the elimination of wastewater streams. Unfortunately, pomace which is produced comprises both, solids and water (OMWW) from the olives and poses again difficulties for disposal, as it is very difficult to handle, dries out very slowly and it is again very polluting.

7

• As a method of pressing, the traditional process entails high labour costs and has certain disadvantages due to the fact that the pressing devices used cannot prevent small pieces of paste from one batch remaining in the press to the next batch, thus contributing to an increase in acidity.

More specifically three-phase centrifugation has the following advantages:

• It enhances the subsequent drying process, since at least 25% of the residual water contained in the “2-phase process” is removed from the paste. This moisture decrease allows for the use of lower drying temperatures, which is favourable for obtaining an oil of better quality in the further chemical extraction.

• Major energy and financial savings are derived because the evaporation of the residual water in the evaporators/concentrators of the power plants takes place with zero net energy consumption. In fact, the process uses the residual energy of the exhaust steam from the turbine.

• It enables a residual water concentrate to be obtained, which is rich in mineral salts, sugars and polyphenols. This concentrate is of high commercial value due to its use as animal feed and organic-mineral fertilizer.

• The resulting residual water is the departure point for obtaining compounds of high added value because they are beneficial to human health

The main olive solid residues which are generated during the olive oil production are the following:

� Pits: The olive stones. � Pomace or virgin pomace or olive pomace or crude olive cake: The residual paste after the

olive oil extraction. It is constituted from a mixture of olive pit/stone, olive pulp & skin, as well as pomace olive oil plus the water added in the olive mills. The moisture content is about 35-70% depending on the olive oil production process.

Table 1: Solid olive oil by-products glossary

English pits or stones

Spanish huesco

Italian nocciolino

Greek κουκούτσι

Croatian koštice maslina

Slovenian koščice

English pomace or virgin pomace or olive pomace or crude olive cake

(The residual paste after the olive oil extraction)

Spanish orujo

Italian sansa vergine

Greek ελαιοπυρήνας

Croatian komina maslina

Slovenian oljčne tropine (Ostanek oljčne drozge po ekstrakciji oljčnega olja)

8

English “traditional system” pomace

(contains:pomace oil, pulp, pits, approx.25 % humidity)

Spanish orujo


Greek ελαιοπυρήνας παραδοσιακού συστήματος

Croatian sirova komina maslina

Slovenian oljčne tropine tradicionalne predelave

(vsebnost: ostanek olja v oljčnih tropinah, meso ali pulpa

(mezokarp), koščice (endokarp), približno 25 % vlage)

English “2-phase” pomace


Spanish alperujo


Greek Διφασικός ελαιοπυρήνας

Croatian komina maslina – produkt 2-faznog centrifugalnog sustava

Slovenian oljčne torpine 2-faznega sistema


(mezokarp), koščice (endokarp), približno 55 % vlage)

English “3-phase” pomace


Spanish orujo


Greek Τριφασικός ελαιοπυρήνας

Croatian komina maslina – produkt 3-faznog centrifugalnog sustava

Slovenian oljčne torpine 3-faznega sistema


(mezokarp), koščice (endokarp), približno 48 % vlage

9

2. Pomace Oil Extraction Process and By-Products (pomace oil solid

residues).

Olive pomace is the solid by-product obtained from the extraction of olive oil. It is made up of skin, pulp and stone (pit, kernel). Olive pomace after the extraction of olive oil still contains some oil, called pomace oil, which can be subtracted with further procedures from the olive pomace. The stone can be separated from the olive pomace in order to be sold as a biofuel, but the extraction may become complicated. Only a minimum quantity of stone is separated to allow drying and extraction in optimal conditions. The pomace oil can be separated in two ways: i) using solvents (traditional method), and ii) through physical extraction or centrifugation (second centrifugation). The first process is based on a solid-liquid extraction where the fats are separated (extracted) with a solvent (hexane). Once this operation has been carried out, the oil from the mixture with hexane is separated through distillation. According to the traditional method, pomace oil is extracted from the dried pomace (8% moisture approximately) with solvent (hexane). Then the hexane, which is dangerous for the public health, is separated from the pomace oil. The product obtained is called crude pomace oil or pomace oil. The extraction of the pomace oil begins with the delivery of fatty olive pomace from oil mills. The trucks from the oil mills unload the raw material in a storage yard. The two components of the olive pomace (the pulp and the stone) are separated. This is because the pulp contains a major part of oil while the stone, which presents an important percentage of the solid, contains so little oil that its recovery is not interesting. The system used for the drying process is a rotating cylinder ,as shown in figure 5, heated internally by hot gases fed from a combustor or burner situated in the front part of the cylinder. The temperature inside the dryer, which is usually made from steel, may exceed 427oC. The rotary dryer has a slight inclination (about two degrees) and except from drying the pomace, acts as a conveying device and stirrer. The flow of the air inside has the same direction with the dried material. To facilitate fast drying, metallic fins are used inside the rotating cylinder so as to blend the pomace. The outgoing dry pomace is carried from the dryer for additional processing. The goal of the drying process is to reduce the moisture of pomace to approximately 8%. Values of final moisture above 10% are highly associated with hexane retention (and the associated potential health effects) in the final product. On the other hand, low (below 8%) moisture levels increase the chance of fire inside the rotary dryer. Furthermore, if the fresh or stored two-phase pomace is subjected to a second centrifugation, it is possible to extract between 40-60% of the retained residual oil. The process is carried out using horizontal centrifugal machines or decanters. The oil obtained is known as “second centrifugation oil” and is commercially classified for its properties as “crude pomace oil”. The pomace enters the rotor through an immobile input pipe and is driven ahead by an inner rotor. The centrifugal forces cause the solids to sediment on the rotor walls. The worm screw turns in the same direction as the rotor, but at a different speed, making the solids move towards the conical end of the rotor. Separation takes place along the cylindrical part of the rotor, and the oil leaves the rotor through adjustable plates on the casing. The extraction of this residual oil by centrifugation can be

10

carried out in two or three phase systems depending on the capacity of the extractors for eliminating the residual water produced in three-phase centrifugation. Figure 5: Material and air flow in the structural parts of a rotary dryer

Source: Rotary Drying of Olive Stones: Fuzzy Modeling and Control, N. C. TSOURVELOUDIS, L. KIRALAKIS,

Department of Production Engineering and Management, Technical University of Crete, University Campus,

Chania, GREECE

Pomace from the traditional extraction system and those from the three phase extraction require different preconditioning procedures than those coming from two phase pomace prior to their extraction with solvent. Figure 6 shows the block diagram of the treatment for pressed pomace or pomace from the three-phase process, where the pneumatically removal of the stone is done just after drying. The stone is separated, in the majority of cases, using separating machines where the air which flows against the pomace current pulls off the lighter pulp particles, leaving behind the heavier and larger stone pieces. To separate the pulp from the air flow which carries it, cyclones are used, which enable the air to be cleaned and emitted into the atmosphere. The pressed pomace and pomace from the three-phase process must be directly subjected to a drying process immediately after leaving the mills in order to prevent the rapid deterioration of the oil, particularly free acidity.

Figure 6: Block diagram of the oil production from pressed pomace or 3-phase pomace

Source: Production of pomace olive oil, By Pedro Sánchez Moral and M Victoria Ruiz Méndez

The other main difference between 3- phase pomace and pomace from the two-phase process lies in the method of removing the stone. Figure 7 shows the block diagram corresponding to the

11

treatment of two-phase pomace in order to obtain oil from this residue by using solvents. Stone removal, as can be seen, is prior to drying and is carried out using mills with filters with approximately 3mm spaces, which allow solids smaller than this size to pass through, expelling the larger stone directly to the drying phase. This provides greater yield in the physical extraction, reduced waste due to the metal parts which rub directly against the paste to be extracted and better exploitation of the resulting by-products.

Figure 7: Block diagram of the oil production from 2-phase pomace

Figure 8: 2-phase production chain of olives to produce olive oil and fuel.

Source: Andalusian Energy Agency/VTT, EUBIONET2 IEE Project

12

This phase is compulsory for the process of extraction of pomace oil with hexane process. This stage consumes a great amount of energy and is under continuous research with the objective of minimizing storage, residence times, energy costs, and to improving the quality of the obtained oil. Normally, drying takes place in rotary heat dryers in which both the product (pomace) to be dried and the hot drying gases are introduced at high temperatures (400 to 800°C). When the pomace leaves the “trommel”, it should have the appropriate moisture content of approximately 8%. The hot drying gases may come from a number of sources:

a) From the combustion of the residual exhausted olive pomace which is obtained after the extraction with solvents of the dry fatty pomace. This is a more widely-used fuel, but it is also the most polluting due to the emission of fine particles produced in the combustion. These fine particles are swept away by the drying gases.

b) From the combustion of stones. This material may come either from the pomace paste itself after the drying phase, or from the previous centrifugation before the physical extraction phase. Due to the low ash content of these stones and the type of combustion, this material is very efficient, in terms of heat, cost and environmental impact. These pieces of stones have found important markets outside, with their exportation being very active. This demand has increased its price, which is nowadays rather high. It should be noted that the olive stones have several important advantages as a fuel:

• It is an annually renewable fuel with zero net contribution to the greenhouse effect.

• It is not subjected to market fluctuations because the material is produced in the same plants where it is consumed. Thus, its price does not depend on the international market for fossil fuels.

• Its combustion produces hot gases in a stable range of temperatures, which may reach up to 800°C.

• With careful control of the combustion, the drying gases broadly comply with European Legislation for gaseous pollutants.

c) The drying gases can also come from the exhausted gases from a turbine or gas engine in a cogeneration process of electricity using natural gas. Obviously, this installation must be close to the drying installation. In recent years, in order to increase profitability, some of such cogeneration plants have made agreements with drying plants for selling them the exhausted gases from their turbines or engines. Alternatively, they have created joint enterprises for this business. From an environmental point of view, the use of these gases is the cleanest system for drying pomace. However, they have two main disadvantages:

• Natural gas is a non-renewable fossil fuel, which is subject to huge market fluctuations. Unexpected high prices for the gas can seriously affect the economic viability of the plants.

• The hot gases produced never exceed 500°C. This circumstance makes the enlargement of the drying facilities necessary. On the other hand, the low temperature of the hot gases produces better quality chemically extracted oil.

The most important element of the drying process is the drying drum, a “trommel”, which consists of a rotary cylinder supported on rolling strips. A toothed sprocket and two rollers control its rotation. The rotation speed depends on the size of the cylinder. The cylinder may be a single or a double passage drier. In the double passage driers, there are two concentric cylinders where the exterior cylinder is supported by the interior one which, in turn, is supported on the rolling strips. There are a series of blades in the interior of the inner cylinder which ensure that the pomace comes into contact with the hot gas flow. They also impulse the pomace to move forward. Inside the drum, the hot

13

gasses transfer their heat to the water contained in the olive pomace, which is evaporated. The gasses and the steam are then put in contact with fresh material until them al cooled to below 100°C. The gasses are evacuated from the drum, together with the produced steam, through cyclones, by an induced draught fan. In addition, this device produces a light vacuum in the drum. Before being emitted to the atmosphere these gases are passed through highly efficient cyclonic decanters which remove the fine particle in suspension and make them suitable for emission. The oil reflects the thermal aggression to which it is submitted by developing brown colours, due to the alteration of the double bonds of the hydrocarbonate chains, and the formation of triglyceride dimers and polymers. Drying also produces an increase in the concentration of oxidized compounds, significantly higher K232 values, and oxidized triglycerides, which increase by 35%. The strong drying process which was applied after the first appearance of the of two-phase pomace caused the formation of an unusually high quantity of Polycyclic Aromatic Hydrocarbons (PAHs), possibly due to the polymerization of the sugars at temperatures above 400°C and the direct effect of combustion fumes on the material to be dried.

Depending on the degree of humidity at the entrance to the dryer, different drying processes can be chosen. At present there are basically three types of drying:

Single stage direct drying. This type of single stage dryer is ideal for pomace cake, 3-phase pomace and two-phase pomace when this has previously passed through the dehydrated physical extraction stage in three phases. This drying system can also be used for 2- phase pomace which does not need to be totally dried, as required for chemical extraction, but will be used as fuel in cogeneration plants with biomass for producing electricity.

Two stage direct drying. This system is ideal for pomace from the three phase process which is to be dried at low temperatures in order to improve the quality of the oils obtained in the chemical extraction step. It is also highly suited to drying 2-phase olive pomace where the first drying stage reduces the humidity to below 50% and the second further reduces it to around 10%, as required for a good chemical extraction.

Direct drying in one stage with recirculation of dried pomace and prior mixing. This system is highly advisable for two-phase pomace, when humidity, after stone removal and physical extraction, is above 70%. The advantage of the procedure lies in the recirculation of part of the dried pomace which leaves the dryer. This material is then mixed with damp olive pomace. The mixture is, therefore assimilated to a pomace from the three-phase process with moisture content

14

below 50% at the entrance to the dryer. The mixture then follows a similar process to that of pomace coming from the 3-phase process, permitting an increase in dryer yield and production.

Chemical extraction with solvents is achieved in three phases: preparation of the fatty pulp, extraction with hexane, desolventization of the extracted pulp and distillation of the fatty miscella. However, after the drying process, the pomace requires certain preparation in order to maximize the extraction efficiency. This is due to the fact that the dried pulp is not appropriate for direct extraction. The main problem is related to the extremely low percolation. Therefore, the treatments have the objective of preparing the pulp so that an increase in solvent penetration into the solid layer could be obtained. This preparation will, therefore, facilitate oil extraction and the subsequent desolventization and extractors’ unloading. This preparation is made by granulating the pulp with machinery which is used, among other uses, in the granulation of compound animal feeding stuffs. However, the fatty "pulp" is not easily granulated due to its high oil content. To improve the conditions of the process, a suitably -sized mesh, (6 x 60 m/m) should be selected, and steam should be used in small quantities as compacting agent. However, the use of large quantities of steam is detrimental because, then, the humidity content of the granule will increase, and this will negatively affect the subsequent extraction. In the former discontinuous extractors stones are still used to increase percolation. In general, if the “granulated pulp” fractions and the stone fragments are going to be remixed for extraction, the degree of compaction is less important than when only the granulated pulp fraction is extracted. In this case, a certain level of compromise is required, enabling good percolation, desolventization and discharging together with good drainage. The advantage of submitting only the correctly granulated pulp to extraction is that the material submitted to extraction is richer in fat. This, in turn, leads to solvent and energy savings as well as an increase in distillation and extraction capacity because the granulated pulp contains, at least, 15% less inert material than if it also contained stones. To achieve this, the pulp must be correctly separated from the stone fragments, which should be sufficiently clean to ensure that the oil content in stones is below 2 %. The extraction with solvent (chemical extraction) process may be achieved in three different types of extractors: Discontinuous These are extractors with simple contact equipment, where both the extraction and the distillation of the resultant miscella are carried out in a discontinuous or batch format. They are no longer used for economic, technical or safety reasons. Semi-continuous This is the most generalized system in the pomace oil sector. In this case, extraction is made through the gradual enrichment of the miscella, using a system of multiple contacts with fixed layers. In other words,, the fresh solvent is introduced into the tank where the solid is most drained in fat, flowing through the different tanks and leaving the system through the most recently filled tank. This takes place in discontinuous extractors but the distillation process is continuous. The system is made up of a series of cylindrical extractors consisting of loading and discharging nozzles, hexane or miscella inputs and steam input for the desolventization. There is also an air output. The extractor itself

15

operates as an extractor and desolventizer. The extractors are loaded with fatty pomace in pellet form from an upper hopper. The exhausted olive cake is discharged under pressure after desolventization. As there are several extractors in the system, the unit is similar to a continuous extractor in that, while one is filling up, others are at the washing with hexane or enriched miscella stage and another is at the desolventization and discharge stage. There are a number of manufacturers of semi continuous extractors differing only in size, in the number of extractors installed and the continuous or semi-continuous distillation system installed. Other differences are insignificant. Continuous In this system, the basic operation of solid-liquid extraction is carried out through multiple contacts in counter current. The input and the solvent enter the extraction stage system at opposite ends. With the system of multiple contacts against the flow, the solid is gradually impoverished in fats from the first to the final stage, while the hexane miscella is gradually enriched from the last to the first stage. The separation efficiency in this type of operation is greater than in the other forms of contact. Most frequently used in the industry are continuous moving solid layer and percolation extractors. The most notable differences between the different suppliers are in the system unit or the extraction unit, which is made up of three basic sections: a) Extraction of oil, and b) Desolventization of pulp – cooling, and, c) Distillation and recovery of solvent. The efficiency of the best-known extractors (DE SMET, ROTOCEL, LURGI, CROWN, EX – TECHNIK) is similar. The differences lie in other aspects, such as: construction quality, knowledge of the raw material, technical service, operating and safety system facilities. The authorized solvent for the extraction of fats is n-hexane. Its main advantages are selectivity, extraction power, almost zero influence on the oil quality, physical properties, (latent heat of vaporization, boiling temperature (60°C), steam tension) and chemical properties (low corrosive action). Certainly, the extraction stages that have suffered major evolution and have been subjected to more conceptual changes with respect to their basic design in recent years have been desolventization and cooling. The reasons behind this pressure for new developments are demands for a decrease in energy and hexane consumption, in addition to questions of safety in storage and transportation. To remove the hexane retained in the solid, a desolventizer is used: it consists of a vertical column made up of various cylindrical trays, each of which has a double base heated by steam. The solvent simply evaporates in the heat into a dry atmosphere in the upper trays. A direct jet of steam is used on the lower trays to remove the majority of the residual solvent from the exhausted olive cake. The exhausted olive cake is usually dried and cooled on additional trays located below those used in the desolventization process. Distillation is the process which separates the components of the dissolution, exploiting the different boiling points of the micelle components through the addition of sufficient heat for the component with the lowest boiling point to distil. Moreover, the addition of heat is combined with the action of a vacuum unit, allowing the temperatures reached to be lower than would be necessary under atmospheric conditions, thus at the same time managing to increase the energy performance of the process and its efficiency. The purpose of the distillation of the miscella is to separate, by evaporation, the solvent from the oil which remains liquid throughout the operation. The following points should be observed during the process: a) the hexane should be recovered in order to reincorporate it into the process. b) The oil should be free of hexane in order to prevent risk in the subsequent processing (storage and refining).

16

The oil should be in the distillation unit for as short a time as possible, only as long as necessary for the finished product to be lower than 150 ppm of hexane in oil. Finally, hexane leaks should be avoided, not only for safety reasons due to the formation of explosive atmospheres, but also because the concentration of hexane saturation in the air is high and increases with temperature. Taking into consideration the fact that in Andalusia there is a large extraction industry, every possible effort is made to ensure that measures are taken to reduce levels of Organic Solvent consumption which currently stand at 6000 t/year compared to 1500 t/year under the National Plan for the Reduction of Annual Emissions of VOCs.

The exploitation of pomace from an environmental point of view may be approached in a number of ways, such as composting gasification, steam explosion treatment for obtaining hydroxytyrosol (or the extraction of oils as presented above. The by-products generated are the stone, the fat-free solid (or exhausted olive cake) and the residual wastewater. The stone has very good properties as a fuel for heating, even for domestic installations. In addition to the use as fuel, with the properties discussed above, stones are also used as abrasive material for cleaning walls, for example, in the manufacturing of furfural, and for the manufacturing of active carbon for the treatment of gases, water or other special applications. The traditional use of exhausted olive pomace is as fuel in drying ovens or steam boilers because of its thermal capacity. As mentioned above, the pomace oil extraction industry is a high energy consumer, particularly at the pomace drying stage and during extraction with solvent. This fact, together with the imbalance currently existing in Spain between the generation of and increasing demand for electrical energy has led the sector to propose electrical cogeneration projects, such that, by exploiting the calorific potential of the exhausted olive cake or the pomace (biomass), it is possible to generate electrical energy and exploit the residual thermal energy for the stages of drying and extraction with solvent. Similarly, the ashes produced in combustion are used to manufacture manures, given their high soluble potassium content. And finally, what is perhaps the newest use of olive mill wastewater, complex agro industries are integrally exploiting the pomace with evaporators/concentrators capable of removing the olive mill wastewater and exploiting the residual energy of the exhaust steam from electricity generating turbines. The liquid generated in this process is used as cooling water in the capacitors and the resulting concentrate is excellent for use in the manufacturing of manures and fertilizers, and for its use as animal feed.

Table 2: Solid pomace oil by-products glossary

English pomace oil or olive kernel oil or olive pomace oil or crude pomace oil

Spanish orujo

Italian Olio di sansa

17

Greek πυρηνέλαιο

Croatian ulje komine maslina

Slovenian ostanek olja v oljčnih tropinah

English dried pomace

(contains:pomace oil, pulp, pits, approx.10% humidity)

Spanish orujo deshidrato

Italian Sansa essiccata

Greek ξηρή ελαιοπυρήνα

Croatian suha komina maslina

Slovenian suhe oljčne tropine

(vsebnost: ostanek olja v oljčnih tropinah, meso ali pulpa (mezokarp),

koščice (endokarp), približno 8 % vlage)

English

exhausted pomace or depleted olive pomace or extracted olive

pomace or exhausted (deoiled) olive cake

(contains: pulp, with or without pits, approx.10 % humidity)

Spanish orujillo

Italian Sansa esausta

Greek πυρηνόξυλο

Croatian iscrpljena komina masline

Slovenian Suhe tropine brez ostankov olja

(vsebnost: meso ali pulpa (mezokarp) z koščicami ali brez, približno 8

% vlage)

Harvesting of olive tree prunings takes place twice a year, once after harvesting of olives and a second time at the end of spring. It is 100% manual operation and there is not any specific field trial for cost estimation. Most of the amount of that type of biomass is burned at the roadside after harvesting. Only high diameter branches are collected and used by inhabitants for domestic heating. A little percentage of these quantities is provided to the wood market, but there is no specific inventory in the area. Proximate analysis and energy content are shown in the following table. The conversion of olive pellets for subsequent heating is being recently considered. Table 3: Proximate analysis and energy content

18

3. Olive oil and solid residues production in Spain, Italy, Greece,

Slovenia & Croatia Most countries along the Mediterranean Sea produce olive oil in varying quantities. Spain, Italy, and Greece represent more than three-fourths of the total olive oil output in the world. The largest producer, Spain, supplies about one-third of the olive oil globally. The olive oil produced in Spain is exported to nearly 100 countries. Italy is the second largest producer, with one-fourth of the world's total production. Greece is the third largest producer, representing about one-fifth of the global total production. With a consumption of about 20 quarts (19 litres) per person per year, Greeks are the largest consumers of olive oil per capita in the world.

Figure 9: Olive figures by producing country

Source: TDC-Olive network

Spain has 2.5 million hectares of olive tress under cultivation, where the Andalusia region (No 1 in the graph below) occupies the southern third of the peninsula and represents the most important region, with about 1,158,959 ha area under production, it produces approximately 75% of the total olive oil produced in Spain. The Andalusia Community is composed of eight provinces, from east to west: Almería, Granada, Jaén, Córdoba, Málaga, Seville, Cádiz, and Huelva. The production of olive oil is extended throughout the region, although it is concentrated primarily in the provinces of Jaén and Córdoba. The province of Jaén, with approximately a quarter of the Spanish olive growing surface area, represents about 40-45% of the Spanish olive oil production and nearly 15-20% of the world production. It is interesting to note that the province of Jaén produces more olive oil than all of Greece. A high number of olive mills exist in Spain. The majority of the olive mills uses two-phase extraction systems. Moreover, there are about 50 pomace oil extracting industries, only 20% of which are Cooperative Societies. They are characterised by the absence of public undertakings and foreign

19

capital. These companies frequently work as extractors of pomace oil, thus prolonging the plants’ utilization period. Figure 10: Spanish and Andalusia regions for olive growing

The Italian olive production covers approximately an area of 1.2 million ha, 80% of which is located in southern Italy, where Puglia represents the most important region, with about 370.000 ha, followed by Calabria (about 186.000 ha) and Sicily (about 60.000 ha). These three regions account for more than 60 percent of Italian olive production. In the centre-north of Italy, the most important regions for olive-tree production are Tuscany (about 108.000 ha), Lazio (about 87.000 ha), Campania (about 81.000 ha), and Abruzzo (about 44.000 ha). The other Italian regions, except Piedmont and Valle d’Aosta which have lesser olive production, cover a relatively small area: Sardinia (about 39.000 ha), Basilicata (about 31.000 ha), Umbria (about 28.000 ha), and Liguria (about 14.000 ha). Figure 11: Distribution of olive cultivation areas in Italy with reference to climate

The main extraction systems in Italy are classic press, continuous centrifugation (two-phase and three-phase options) and various mixed systems plus the percolation system, which is statistically

20

insignificant. Mixed systems can be defined as a whole group of possible combinations between the first two types. For example, a roller crusher, typical of a traditional extraction, can substitute a disc crusher or a hammer crusher in a continuous processing line. On the contrary, a disc crusher can be placed before a press, normally after the mixer. Mixed systems can be sometimes a solution to specific problems and should represent about 9% of all extraction systems, though they are often identified with the continuous group. On national basis, the press and the continuous systems seemed to equal each other (44.8% the first and 45.6% the second) until the end of the ’90 but today things have changed and the centrifugal technology prevails on the traditional. Giving a close look to the different regions, the continuous prevails remarkably in the south while the press system still plays a major role in the centre-north of the country. No data are available on the percentage incidence of two-phase and three-phase options within the continuous centrifugation category. Greece devotes 60% of its cultivated land to olive growing. Greece holds the third place in world olive production with more than 132 million trees, 3000 mills and 220 bottling companies which produce approximately 350,000 tons of olive oil annually, out of which 82% is extra-virgin. About 30% per cent of Greek oil is produced in island Crete, 26% in Peloponissos (southern peninsula), 10% in the Aegean island of Lesvos, 10% in the Ionian Islands (Adriatic Sea) and the remaining 24% is scattered around the rest of the country. Olive groves represent 20.5% of total farmland and olive oil production 14% of total plant production. In total approximately 1,200,000 hectares of land grow, over 140,000,000 trees. Only one sixth of those trees are intended for table olive production. Consumption of olive oil in Greece is the highest in the world, 23 kilos per capita, compared to the E.U. average of 4.65 kilos, Spain’s 13.68 and Italy’s 12.41 (Source: International Olive Oil Council). Figure 12: Distribution of olive cultivation in Greece

Figure 13: Olive Oil production in Greece

21

There are about 2,700 registered olive mills in Greece. The vast majority of the producers are small scale land owners with 3.2-4.8 ha or less. The percentage of the olive mills depending on the extraction method used is: 80% olive mills using the three-phase method, 18% use the classical extraction method and a very small percentage use the two-phase or “ecological” two-phase method. These percentages are not related to the production volumes. There are near 520,000 olive growers, 50.5% of which are professional farmers. The large number of olive growers in relation to the cultivated land reveals that there is no large scale industrialised olive farming. This means that olive cultivation although systematic and much improved by the application of recent technological developments and scientific progress still remains a “family” affair.20% of the mills are cooperative ones while the rest belong to the private sector. Private mills are usually small family operations. The average mill employs specialized personnel (1-2) and some 3-4 non specialized labourers. There are 35 olive pomace extraction plants in Greece with the largest number concentrated in Crete (11) and the Peloponnese oil (10). Crude Olive Pomace Oil production comes to an average of 40,000 tons per year. The average production of olive groves is particularly high, 360 kilos/ hectare when the corresponding world average is 160Kg/ hectare. In certain areas such as Crete average production is even higher going up to 500Kg/ hectare. Table 4: Type of Olive solid residues

Country Data

Type of solid residues Number

of olive-

mills

Olive

cultivation

area (in ha)

virgin

pomace

dried

pomace leaves pruning pits

Spain

National × × × × × 1722 2.509.677

Regional

-Jaen- × × × × × 327 n.a

Italy

National × × × × × 6000 1.200.000

Regional

-Liguria × × × × 180 13.500

Greece

National × × × × × 2500 1.125.000

Regional

-Crete- × × × × × 124 41.759

Croatia

National × × × × 125 30.000

Regional

-Istria - × × × × 18 3.600

Slovenia

National × × × 12 1470

Regional

-Istrian - × × × 11 1420

22

Table 5 Type of Olive oil production methods

Country Data

Production methods used

Traditional 2 phase

centrifugal

system

3 phase

centrifugal

system

Other

Spain National 100%

-Jaen- 100%

Italy National 37.5% 0.7% 47.5% Mixed (2.5) - 9,6 %. Other- 4,2 %

-Liguria- 52% 0,005% 30% Mixed (2.5) - 13 %. Other- 0,02%

Greece National 5% 7% 88%

-Crete- 1% 5% 94%

Croatia National 43% 57% (2-phase and 3-phase)

-Istria - 6% 63% 31%

Slovenia National 33,3% 33,3% 33,3%

-Istrian - 36% 27% 36%

Table 6: Olive by-products

Country Data

Quantity of (tn/year)

produced

olive oil

virgin

pomace

dry

pomace

(with pits)

pit/stone

Spain National 1.230.000 4.920.000 4.222.000 2.500.000

-Jaen- 544.555 2.058.221 1.770.378 1.050.000

Italy

National 721.418 n.a n.a n.a

-Liguria- 5.500 12.000 Not

existing

3.240 potentially

(27% of virgin pomace)

Greece National 352.000 598.000 53.800-161.500

-Crete- 33.300 n.a 56.500 5.100-15.400

Croatia National 5.000 18.200 n.a 3.640

-Istria - 810 3.509 n.a 710

Slovenia National 275 1100 n.a 281

-Istrian - 255 1000 n.a 258

23

4. Energy Exploitation Methods Thermochemical processes are quite flexible in their current application and it can be stated that no installation is similar to another. On the other hand, it is also true that installations are less bulky, simpler and smaller compared to biochemical ones, whereas they have to use heat and/or gas immediately. A customised exhaust filtering system must be used in order to avoid environmentally harmful gases. These thermochemical processes are: combustion, gasification, pyrolysis. These processes are the simplest to apply and they are based upon the thermal transformation of the biomass when subjected to high temperatures (300-1500 oC). Figure 14: Overview of thermochemical processes.

Source: CRES – Centre for Renewable Energy Sources

The simplest way to exploit olive solid residues for energy production is by direct combustion. This can take place however, only after olive pomace is dried. Combustion type of boilers gives off their heat to radiators in exactly the same way as e.g. an oil-fired one. These boilers are mainly automatic; since they are equipped with a silo containing olive dried pomace or exhausted pomace. A screw feeder feeds the fuel simultaneously with the output demand of the dwelling. A typical example of dried or exhausted pomace boilers is shown in figure 15 Advantageous features of these kinds of boilers are the high thermal efficiency, the low operation cost and the need of non frequent cleaning. Despite an often simple construction, most of the automatically fired boilers can achieve an efficiency of 80-90% and a CO emission of approximately 100 ppm. For some boilers, the figures are 92% and 20 ppm, respectively. An important condition for achieving these good results is that the boiler efficiency during day-to-day operation is close to full

24

load. For automatic boilers, it is of great importance that the boiler nominal output (at full load) does not exceed the maximum output demand in winter periods. Figure 15: Mile Boiler P, Samaras, Greece

Figure 16:Energía de la Loma, S.A, Spain.

In terms of large scale plants utilizing olive husk, fluidized bed combustors proved to be a reliable solution. In a fluidized-bed boiler, the fuel is fed into a solid bed, which has been fluidized, i.e., lifted off a distribution plate by blowing air or gas through the plate. The amount of bed material is very large in comparison to that of the fuel. Fluidized bed combustors have a variety of advantages, including their simplicity of construction, their flexibility in accepting solid, liquid or gaseous fuels (in combination and with variable characteristics), and their high combustion efficiency at a remarkably

25

low temperature 750-950 °C which minimizes thermal NOx generation and enhance the efficiency of SO2 absorption from the products of combustion. Fluidized bed units are eminently suitable for intermittent operation. The fluidized bed (FB) boilers provide good possibility to burn several different fuels in the same boiler: coal, peat together with biomass, waste, recycled/recovered fuel (REF) or refuse derived fuel (RDF). The combustion may take place under atmospheric or high pressure either in bubbling (BFB) or circulating fluidized bed (CFB) boiler. FB boilers are well controllable because of the fluid like bed and are reliable in operation. Furthermore, the ashes produced after combustion can be used as additives in manufacture.

The gasification process can be broken down into three phases. The first phase is a process of pyrolysis during which the biomass is converted by heat into char and volatile matter, such as steam, methanol, acetic acids and tars. The second phase is an exothermic reaction in which part of the carbon is oxidized to carbon dioxide. In the third phase, part of the carbon dioxide, the volatile compounds and the steam are reduced to carbon monoxide, hydrogen and methane. This mixture of gases diluted with nitrogen from the air and unreduced carbon dioxide is known as producer gas. If the original feedstock is charcoal, then the gasification process becomes two-phased, and the amount of tar produced is cut down. A composition of olive kernel gasification with air mixture is shown in table 7. Syngas (from “synthesis gas”) is the name given to a gas mixture that contains varying amounts of carbon monoxide and hydrogen generated by the gasification of a carbon containing fuel to a gaseous product with a heating value. Syngas consists primarily of carbon monoxide, carbon dioxide and hydrogen and has less than half the energy density of natural gas. Syngas is combustible and often used as a fuel source or as an intermediate for the production of other chemicals. Syngas for use as a fuel is most often produced by gasification of coal or municipal waste. Four types of gasifier are currently available for commercial use: countercurrent fixed bed, co-current fixed bed, fluidized bed and entrained flow. Concerning olive dried pomace the fluidized bed reactors have already been tested in terms of gasification. Table 7: Gas mixture from olive kernel gasification with air

Component % vv

CO 8.6

CO2 21.7

H2 5.4

CH 4 3

C2H4 1.6

C2H6 0.3

N2 59.46

Tar production in this case seems to be the major problem which this procedure faces, since it is formed at a temperature of ≈800°C and disturbs the fluidization. Another problem to solve during this process is the gas cleaning from tar and other suspended solids that come from fluidized bed or chars. Ash-related problems including sintering, agglomeration, deposition, erosion and corrosion, due to the low melting point ash of agroresidues consist a main obstacle for economical and viable application of this conversion method for energy exploitation of the specific residues

26

Pyrolysis is the transformation of a compound or material into one or more substances by heat alone (without oxidation); in other words thermal decomposition. Pyrolysis is somewhat similar to vaporization, however, it is a relatively slow chemical process compared to the vaporization. The temperature at which pyrolysis occurs depends on the fuel type and the heating rate. Coal for example pyrolises at about 420oC. This temperature is below the spontaneous ignition temperature of coal. Pyrolysis products consist of volatile gases, liquids (tar), and char generally. Products range from lighter volatiles to heavier tars. The composition of the volatile matter (gases), products of pyrolisis, depends also on the fuel. Pyrolysis of biomass is the thermal degradation of the material in the absence of reacting gases, and occurs prior to or simultaneously with gasification reactions in a gasifier. The liquid fraction of pyrolisised biomass consists of an insoluble viscous tar, and pyroligneous acids (acetic acid, methanol, acetone, esters, aldehydes, and furfural). The distribution of pyrolysis products varies depending on the feedstock composition, heating rate, temperature, and pressure.

BIOCHEMICAL PROCESSES

This biochemical process consists in the treatment of the biomass introduced in a digester without oxygen. After the biomass is introduced in the digester, a bacterial culture which is responsible for the biogas production is added. The anaerobic digestion is not the only option in the biological treatment of vegetable water, but is the most widespread application of waste management for energy exploitation. In this process, and after having homogenised the biomass that is going to be used, a mixture of gases is obtained; the most important one is methane. This process depends on the operation temperature. This operation parameter is fundamental in order to obtain a good yield during the process. Dependence of this process on temperature is due to the bacteria charged for the digestion, which acts at certain temperatures. The biogas produced is responsible for the biomass agitation that takes place in the digester. The obtained biogas in anaerobic digestion is obtained at the rate of 300 l/kg of dry material, with an approximate calorific value of 5,500 Kcal/m3. The biogas composition is variable, but it is predominantly formed of methane (55-65%) and carbon dioxide (35-45%) and in less proportion, nitrogen (0-3%), hydrogen (0-1%), oxygen (0-1%) and hydrogen sulphide (tracks). Anaerobic digestion is appropriate for high humidity biomass treatment, since a watery mean helps the process. The fuel used will be the one which could be digested, depending on the fat material, humidity, etc. Degasified two-phase pomace or “alperujo” can be energy used in a biomass direct combustion thermoelectric power station. Biogas can be used to generate heat and/or power, as well as treated as a transport fuel. The digested residual, on the other hand, can be applied to the land-farm, instead of inorganic fertilizers to improve soil fertility.

27

Hundreds of biogas applications have been established during the last two decades in Europe. The biogas schemes applied include several technological solutions characterised by different digester design, mixing process, filtering and various end uses.

Recent studies report the use of fermentation processes, as a way to obtain some interesting industrial bio products (bio alcohols). During many years of applied research, attention has been paid to the use of acid and enzymatic hydrolysis processes, in order to convert the lingo-cellulosic residues into fermentable sugars to obtain ethanol, unicellular protein and several chemical products. Generally, most of the ligno-cellulosic residues, before being submitted to fermentation, have to be submitted to a series of treatments, in order to optimise conditions. The complete sequence would be:

• Pre-treatment by mechanical, physical or biological ways.

• Chemical or enzymatic hydrolysis.

• Hydrolysed conditioning.

• Fermentative processes: in co-culture and in a sequential way, throughout a sacharification and simultaneous fermentation, by direct microbial conversion.

Currently many technologies are been developed in order to obtain liquid bio fuels (ethanol) from lingo-cellulosic materials. Two main lingo-cellulosic materials sources exist in the olive oil sector: the two-phase or “alperujo”, the three-phase pomace, and the olive grove pruning. Research in three-phase pomace (which could be also extended to two-phase pomace or “alperujo”), is done by separating the extracted pulp from the pit fragments, using temperatures between 190-236 ºC and time periods between 120-240 seconds, has achieved a selective solvolysis of their main compounds (lignin, hemi cellulose and cellulose). After a fast auto hydrolysis process (steam explosion) the result is one soluble and another insoluble fragment.

The average heating value of dry pomace (with stones, low moisture content) is 3500-4000 kcal/kg while for pits is 4000-4500 kcal/kg. Table 8: Comparison of Heating Values of Olive by-products

Kcal/kg Spain Italy Greece Slovenia Croatia

Average heating value of dry pomace

(with stones, low moisture) 3800 n.a.

3.500 –

4.000 4.216 n.a.

Average heating value of virgin pomace

( with pomace oil & pits, high moisture) 1800 1.800 n.a.

4.604 –

4.974 4219

Average Heating value of pit/stone 4100 4.750 4.500 4.805 4.500

28

As we can see from the table 8 dry pomace and pits have a little less heating value as compared to coal and a little more than wood. The energy potential than can be produced in each country is depicted in table 9 below. Table 9: Energy Potential from Olive by-products

Table 10: Heating value of fossil fuels.

Fuel kcal/kg

1 Propane 11060

2 Butane 10940

3 LPG Mixture 10960

4 Diesel 10200

5 Fuel Oil 9600

6 Town Gas 9100

7 Coal 4498

8 Wood 3890

9 Natural Gas 8300 – 9700 kcal/m3

Regional data

MWh/year Spain

~Jaen~

Italy

~Liguria~

Greece

~Crete~

Slovenia

~Istria~

Croatia

~Istrian~

Energy potential of dry

pomace(with stones, low

moisture)

3.183.064 n.a. 231.700-

267.400 n.a. n.a.

Energy potential of virgin

pomace ( with pomace oil &

pits, high moisture)

4.307.906 25.000 4.587 17.206

Energy potential of

pit/stone 5.005.814 17.898,57

26.780-

80.330 1.570 4.930

29

6. The current supply chains and the end-uses of solid residues in each

region.

Province of Jaen Jaén is the region with the main production of olive oil in Spain. Therefore the elimination of the waste is very important in this process. To eliminate the residues, the olive-mills use a 2-phase process: Olive pomace results from the extraction of olive oil through physical processes. With a variable composition, it is mainly used as a raw material to extract the residual oil that remains in the solid cake, prior to drying. A by-product designated as virgin pomace is obtained (humidity 62-70%) that goes through a pitted machine, while the pit is mainly used as fuel to produce heat for thermal use. Afterward, the virgin pomace goes through a process of drying and extraction and new by-product results, designated dry pomace (humidity 10%). This by-product is mainly used as fuel to produce electricity. Figure 17: Supply chain chart

Both of the following two types of energetic applications of the olive grove solid residues are used in Spain: 1. Thermal application: The biomass (olive solid residues) is used for the domestic sector, for

heating and sanitary hot water (SHW); also at industrial level for steam process that comes from reused residues.

2. Electrical application: The technology used for obtaining electricity is the Rankine vapour cycle, with generation or co-generation (heat + electricity) electrical plants (steam conventional cycles). Another alternative is the electricity generation through gasification processes.

The optimal electrical energy plant size is between 10 to 25 MW, the normal size is 25 MW so that it is the most profitable. Since some years ago, the Spanish Government began to promote thermal installations, but at the beginning problems or barriers in energy exploitation were existed. In Spain the development of the sector (of biomass installation) depended on two factors: Logistics & Distribution. Nowadays, a lot of

30

companies related to this sector create new distribution companies that supply biomass to all the thermal installations. Figure 18: Energy Production Potential from Biomass in Andalusia, Spain

The biomass industry remains underdeveloped in most industrialized countries. It supplies just three per cent of Spain’s total electricity consumption, while in most industrialized countries the figure is only one per cent. This is mainly due to lack of government support. Spanish biomass electricity producers receive a premium on top of the normal price for electricity; however this premium is not high enough to make biomass attractive to most investors so it is necessary to increase the premiums for the biomass sector. The implementation of the biomass electricity installations mainly depends on government policy. In the years 2004-2007, the price of which was established by government, were not profitable for implementation of olive-pomace installations. Finally in May 2007 the prices changed and investments in the biomass sector helped to develop old projects and start new ones.

Potential facilitating factors, opportunities or barriers concerning the energy exploitation of olive residues:

Biomass energy is increasingly popular as an alternative energy source for a variety of reasons:

• It is widely available in the region (Jaen).

• It can provide solutions to the climate change issue. The use of biomass does not increase atmospheric levels of carbon dioxide, a primary greenhouse gas, because of the life-cycles of plants and trees. The use of biomass can also decrease the amount of methane, another greenhouse gas, which is emitted from decaying organic matter. Biomass is a renewable, CO2 –neutral, fuel making it a valuable technology in efforts to reduce CO2 emissions in order to curb global warning and climate change.

Spain’s olive-mills use a process of two phases to eliminate olive grove residues. This process is the most appropriate for the extraction of olive oil: Olive residues can be composted, burned, use for heating, for animal feed supplement or returned to the olive trees as mulch. The biomass or wastes represent a cheap and technically feasible option to contribute to the reduction of the CO2 emissions.

31

• When utilizing the 2-phase system the fresh water consumption is reduced and also the wastewater streams are eliminated.

• When the refined oil is extracted, the leftover fibrous material is primary lignin and cellulose. This residue has still a high calorific value, and it can be composted, burned, use for heating, for animal feed supplement or returned to the olive trees as mulch.

• The remaining leaves and stone can be pyrolysed under non-oxidative atmosphere or gasification can take place with energy or alternative fuel production. It can be a solution to the environmental problems that their land filling or combustion could create.

Liguria Region Ligurian millers are craftsmen who work third party’s olives (imported olives) or their own’s (local olives). The quantity of residues therefore depends on imports but it is not easily figured. Most millers (over 60%) deliver pomace to pomace refineries: there are 2 small refineries in Liguria, but most pomace is sent to Tuscany or Latium (where there are big refineries) that pays very little money (more or less as much as the transport cost). Therefore, in Liguria there is only virgin pomace potentially available. The other millers use pomace for agronomic use (10%) and the rest dispose of it in another way. Liguria has a few pilot projects for alternative disposal of pomace (calcium addiction to 2-phase pomace and then delivery to a biomass plant located in another region) but there are environmental, procedural, legal or technical difficulties. Olive pit separation from virgin pomace (pit recovery range amounts to 18-30%) seems to have the highest potential in terms of heating value and price. At the moment pits are not purchasable in shops, only some mills sell them directly. There is a small district heating system in Arnasco fuelled with pit. The following energy applications can use olive solid residues. Anaerobic digestion: widely applied 40-50% of organic material is transformed into biogas which can be used to generate electricity or thermal energy. The main drawback is the production of small quantities of mud.

Gasification or combustion: to produce thermal energy or for cogeneration. Gasification allows using virgin pomace which is transformed into syngas made of CO and H. In Italy syngas is used to generate electricity in Calabria in a plant owned by Guascor. It produces 23MWt and 4.2 MWe. This kind of plants has the advantages that pomace does not need to be dried and high performances, but they need big quantities of pomace. The small quantities of pomace available in Liguria make it not economically viable the use for this kind of plant application. Direct combustion is motivated by the high heating value of the pomace which is 4.65 kWh/kg (the pit has a heating value of 5.4 kWh/Kg and can be used as it is or to produce pellets). Unfortunately for direct combustion it is needed to have dry pomace (according to law) but in Liguria there is only virgin pomace. In Italy there exist biomass plants burning dry pomace together with wood chips and other biomass.

• In Liguria there are cases of pit separation and consequent use it as domestic fuel. It is also sold for the same aim.

32

• There is a case of use of calcium for pomace drying (UNIECO) at Lucchi & Guastalli mill with subsequent use as fuel in biomass boilers (in Tuscany and Lombardy)

• There is a small (70 kW – 64 mt length) district heating plant running with olive nut in the municipality of Arnasco. It heats up the church and the annexed building.

Figure 19: Pomace production in the region of Liguria divided in province areas below


• Green certificates for electrical energy

• Possibility to use heat for the many greenhouses in Liguria (flowers and farming)

• Funding opportunities for <1MW plants, coming from the Rural Development Plan 2007-2013

• Mills have a low energy demand (for electricity in the range 16-70 kW and for heat around 40.000 kcal) therefore there is a need for different potential users.

• Presence of virgin pomace only and absence of regional pomace refineries therefore, need to find a way to dry pomace in order to increase its heating value. Pelletising could be a solution?

• Presence of many scattered small mills, therefore the transport factor becomes crucial in the feasibility study. And transport in Liguria is particularly difficult due to orography

• Presence of different milling systems, which generate different kinds of pomace.

• Seasonality of residues.

• Different crop yield each year.

33

Chania Region

In Greece oil refineries buy virgin pomace from olive millers, extract pomace oil from virgin pomace and they use the exhausted pomace either for their own energy needs or they sell it to the millers as a heating fuel. Dried or exhausted pomace is mainly used for heating purposes today on Crete for:

a) Houses b) Greenhouses c) Various small-sized industries

Today, exhausted pomace is used extensively in Crete for heat production; in the future, it has very good prospects in power generation and/or heat and power cogeneration. Since a large proportion of power in Crete is generated today from wind energy, it is likely that, in the future, biomass will also contribute to the generation of green electricity Figure 20: Supply chain chart

Its heating value is 3500-4000 Kcal/ kg (with a moisture content of 12%) and its price is approximately 0,05 Euros/ kg; thus, it is a very attractive option as a fuel in comparison to oil. Dried or exhausted pomace, however, has not yet found applications in power generation or cogeneration of heat and power in Greece. Because it can be easily burnt and the combustion technology is well known widely, it can be used as a solid fuel for power generation in the future. Presently, it is used in houses and in greenhouses for space heating and hot water. Also, it is used in various industries for drying purposes and/or for hot water heating. Greece exports small quantities to other European countries each year, where dried or exhausted pomace is used as fuel. The required machinery for the dried or exhausted pomace combustion is the boiler (including the burner), which is quite simple to use and not expensive. These boilers are reliable and made locally.


34

Dried or exhausted pomace can be used for power generation or cogeneration of heat and power in Crete, since it presents many advantages, such as:

• There is no need for harvesting of raw materials and transportation because it is produced in the dried or exhausted pomace processing plants.

• Its moisture content is very low and its heating value is high.

• Its price is rather low in comparison with its heating value.

• The combustion technology is well known. Since it is granular, either fixed bed reactors or fluidized bed reactors can be used.

• The generated power can be consumed either inside the plant or can be sent to the grid.

• The Greek Government offers good subsidies for investments in the field of Renewable Energy Sources and, of course, in Biomass.

• The use of Biomass for power generation in Crete will reduce the CO2 emissions on the island.

• In the case that such a plant should be created, various other solid agricultural residues can be used together with the Olive Kernel Wood as raw materials.

• The creation of such a plant will help in power generation to and from small-decentralized plants instead of larger centralized power plants that exist today in Crete.

• The sulphur content of dried or exhausted pomace is minimal.

• The efficiency of small-sized combustion plants is very low. The dried or exhausted pomace processing plants operate seasonally. The produced heat from dried or exhausted pomace should be used at the time that cogeneration of the heat and power is obtained (during its operational period which is from November – April), or outside the plant for nearby heat-requiring operations.

• Initially, the price of the dried or exhausted pomace may rise, due to an initial local deficit of this Biomass source.

• Nowadays, fewer people work in agriculture. There are no incentives or opportunities to the farmers to exploit olive residues in order to produce energy from them.

• People should be informed about the environmental and energy benefits of the olive residues exploitation.

• Cretan’s admitted that they would like to exploit olive residues only if they had a financial incentive.

• Most millers are at a senior age and lack knowledge about new possibilities and procedures for olive residues exploitation.

Table 11: Relationship between Energy production & Energy consumption in ABEA olive industry

Year

Total Energy

production (Biomass)

(1010

kcal)

Total Energy

consumption (Biomass

+Electric)

(1010

kcal)

Energy production/

Energy consumption

2001 4.7 2.72 1.73

2002 7.1 4.54 1.56

2003 5.7 3.84 1.48

35

Figure 21: The island of Crete

Figure 22: The region of Chania in the island of Crete

Table 12: Olive residues production in Crete.

olive residues Production (tn) 2003 Yearly change

Average heating

value

(kcal/kg)

Thermal Energy

production

(109kcal)

pits 103695 +8.553 4437 460

olive prunings 1550723 +57.670 3990 6187

Istria Region

36

In Slovene Istria, olive residues are usually (95.4 % of residues) composted and returned to the olive groves as fertilizer. The composting of olive residues is integrated in the processing cycle of each oil mill. After the 3-6 month composting period, the olive residues are spared on the surface as fertilizer, returning nutrients to the soil. Only 4.6 % of olive residues are used for energy purposes, to generate heat. This amount of residues produces enough green energy for heating two households. Until now there is no any supply chain in Slovene Istria region. The end users of olive residues are now mainly olive millers which use olive residues for composting. Two of them use olive residues for their private energy purposes (heating). Both of them have around 60 tons of residues per year. If they would use all of residues, it would be enough energy for heating at least 5 more households. Presently they are heating only their own two households. In figure 23 we can see the current supply chain & end-uses of residues in the region of Istrian. Figure 23: Supply chain chart

In figure 24 are shown new capacities for local generation of electricity from Renewables. Planned development of electricity generation from renewables does not include the energy exploitation of olive residue, because of their small quantities. Figure 24: RES production and planned new capacities

0

100

200

300

400

500

600

2006

Cap

acit

ies

(MW

h)

Small hydroelectric

station

Wind

Landfil gass

Purification plants

Biogass

Wood

Solar

Olive residues

0

10

20

30

40

50

60

70

80

90

100

110

120

2010 2020

year

New

cap

acitie

s (M

Wh)

Small hydroelectric

station

Wind

Landfil gass

Purification plants

Biogass

Wood

Solar

Olive residues

37

In Slovenia olive residue is treated as waste and not as secondary product. They don’t use olive residue for energy most of them are thrown away or use like fertilizer in olive fields. Two best practices are identified in SLO Istria region, where olive miller uses olive residues mostly as fuel for house heating and water heating. A description of the above two mills follows: 1. The first is a 3-phase mill. After olive oil extraction, olive residues are too wet to burn

immediately and therefore disposed to the field/meadow behind the mill. Olive residues are left to dry on the open space. Olive residues are mixed up/turned upside down several times to speed up the drying process. After certain time they are collected and loaded into big wooden containers and stored in the shed next to boiler room. Dried olive residues are used directly for burning/combustion in the stove.

2. The second mill is a traditional one which in past they used to dispose olive residues back at olive fields. Today they put them directly into a wooden container in order to dry them on open air (but under roof) and use them only for energy purposes; production of heat for heating private house and olive mill (ca. 250 m²).

Figure 25: Slovenia

Table 13: Olive mill data

Št. Mill name Name Surname Address ZC Town Technology

1 Oljarna TORKLA Beno Bajda Obrtna ulica 11 6310 Izola 2

2 Kocijančič Ido Kocjančič Frenkova 5 6276 Pobegi 2

3 Oljarna Torkla Šalara Franko Lisjak Obrtniška ulica 26a, Šalara 6000 Koper 2

4 Oljarna Torkla Krkavče Patricij Ternav Krkavče 97 6274 Šmarje 2,5

5 Oljarna Prinčič Prinčič Sv. Peter 18 6333 Sečovlje 2

6 Oljarna Krožera Fulvio Marzi Srgaši 40 6274 Šmarje 2,5

7 Oljarna Peroša Viktor Peroša Nova vas nad Dragonjo 8 6333 Sečovlje 3

8 Oljarna Čok Erika Čok Plavje 10 6281 Škofije traditional

9 Oljarna Oljka Evelin Toškan Vanganel 40 6000 Koper traditional

10 Oljarna Hrvatin Marinko Hrvatin Ul. 15 maja 10b 6000 Koper 2

38

11 Oljarna v Brdih Zadružna cesta 9 5212 Dobrovo v

Brdih 2

12 Oljarna Agapito Ivan Agapito Spodnje Škofije 15 6281 Škofije traditional

Technology Olives processed (t) Olive oil production (t) Olive residues (t) Waste water

(t)

Traditional 305,8 61,2 122,3 183,45

2 phase 612,7 122,5 536,1 122,54

2,5 /3 phase 304,5 60,9 167,5 334,98

SUM 1223,0 244,6 825,9 640,97


• Based on upward trend of petrol prices on global markets and breakthrough of new technologies, which use alternative / renewable sources of energy (for instance wood biomass in Slovenia), the use of olive residues could be an alternative source of energy, in first place for heating / production of heat and later for production of electricity.

• Since the quantity of olive residues in Slovenia is very small, the exploitation of these is not suitable for larger energy plants, such as large heating stations or power plants. Their use is most suitable for heating individual olive mills and private households, which are in direct proximity of olive mills. These conclusions are based on calculation of ratio between yearly energetic potential of olive residues, comparing to yearly energetic needs for energy in Slovenia, which is very low.

• Usage of olive residues has very important impact on the environment. Figure 26 below shows emission comparison between extra-light heating oil and olive residues (if they would use all olive residues in Slovenia for heating).

Figure 26: emission comparison between extra-light heating oil and olive residues

0

500

1.000

1.500

2.000

2.500

CO2 * 1000 SO2 NOx CxHy CO * 100 dust

kg

ELKO Olive residues

In calculation of emissions, CO2 is not considered as the result of burning olive residues. Although biomass releases carbon dioxide (CO2) into the atmosphere when combusted, the amount of CO2 released is equal to or less than the amount that the crop absorbs while growing (net emissions of CO2 are zero).

39

Istrian region

The Istrian region (Croatia) has a long olive growing and oil producing tradition. According to the latest official statistical data, a total of 600,000 olive trees are cultivated in Istria. Lately, traditional extensive olive cultivation methods were replaced with intensive modern growing technology, and olive growing has become attractive trend in agriculture. Moreover, the olive oil is one of the most important typical food products in Istria. The olive oil market has recently improved especially since the consumers pay more attention to both health and nutritional aspects of food. Olive sector in Istrian Region (Croatia) is organized as follows: Olive producers use services of 18 olive mills, mostly SME’s (Table 14, Figure 28). Olive mills produce olive oil and they are responsible for olive mill waste management. The treatment of olive milling residues in the region encompasses different treatments. Table 14: Olive mill data

Št. Mill name Name Surname Address Zip code Town Technology

1 Agro Millo Valter Smilović Baredine 16 52460 Buje 2

2 Agrofin Boris Vekić Zambratija bb 52475 Savudrija 3

3 Al Torcio Tranquilio Beletić Ulica Torci 18 52466 Novigrad 2

4 Baiocco Andrej Đurić Galižana 8a 52216 Galižana 3

5 Brist d.o.o. Silvano Puhar Ušićevi dvori bb 52203 Medulin -

6 Kraljević – CUI Danijel Kraljević Farnežine 52470 Umag 2

7 Olea d’ oro Germano Kraicer Partizanski put bb 52100 Pula 3

8 Pastorvicchio Antonio Pastorvicchio Istarska 28 52215 Vodnjan 2

9 Pavlović Alojzije Pavlović Crveni vrh bb 52475 Savudrija -

10 Pilar – Stella Maris Pilar family Stella Maris 52470 Umag 2

11 Torač Franko Vladišković Žbandaj bb 52440 Poreč 2

12 Babić Ante Babić Stancija Vineri bb 52466 Novigrad 3

13 Bronzi Sergio Černeka Bronzi 51 52420 Buzet 2

14 Brtonigla Šišot family Ronko bb 52474 Brtonigla Traditional

15 Pašutići Miljenko Prodan Pašutići bb 52420 Buzet 2

16 Agrolaguna Agrolaguna d.o.o. M. Vlašića 34 52440 Poreč 2

17 Rovinjsko selo Miro Pokrajac Rovinjsko selo 50 52210 Rovinj 2

18 Agroprodukt d.o.o.

Agroprodukt d.o.o. Trgovačka 135 52215 Vodnjan 3

Olive mill owners manage waste waters mostly using physical treatment processes in their own organization or by means of waste management companies. There are also some cases of OMWW releasing in the environment. In Croatia, olive residues are treated as a waste and not as secondary products. But, there are some cases of crude pomace treating as an organic fertilizer, usually placed back to the olive fields (with or without composting). Some mills deposit pomace in the mill vicinity

40

or release it in the environment. There are a very few cases of using pomace for energy purposes (as furnace fuel). At the moment in Croatia there is a lack of successful energy exploitation of olive residues. Quantities of residues are relatively low in Croatia but in the following period significant increasing could be foreseen. Figure 27: Supply chain chart


One of the main goals of Croatian energy development sector is to increase the use of renewable energy sources. The advantages of energy end-uses of these residues are:

• The improvement of olive waste management

• Not increase atmospheric levels of carbon dioxide, a primary greenhouse gas and at the same time it can also decrease the amount of methane, another greenhouse gas, which is emitted from decaying organic matter. Biomass is a renewable, CO2 –neutral, fuel making it a valuable technology in efforts to reduce CO2 emissions in order to curb global warning and climate change.

Figure 28: Location of olive mills in Istrian Region

41

Creation of supply olive-residues-to-energy chains could be the optimal solution for olive residues management in the region but some problems for the energy exploitation could arise:

• In Istria (and Croatia) there is no olive cake collecting centres or facilities for their drying and energy producing.

• Generally, limited access to information on regular and appropriate waste management • Existing producer’s attitude of non profitability on pomace use in energy purposes (results of

feasibility studies). • High percentage of olive oil in pomace in Croatia (no pomace oil extraction) requires a special

approach in energy production.

• Crucial factor for the feasibility study are transport expenses, due to olive mills dislocation

• Presence of different milling systems and different residues content

• Seasonality of olive residues production and different crop yield each year

Figure 29: Olive growing and olive oil production regions in Croatia

Istria

Dalmatia

42

7. National and Regional policy aspects

ROYAL DECREE 661/2007 The special regime for the production of electricity from renewable sources (wind, solar and biomass) was contemplated by in the Electricity Act 54/1997, which is still in force. Royal Decree 661/2007, which was published on 26 May 2007, regulates the production of electricity under this special regime. This royal decree supersedes Royal Decree 436/2004, passed in March 2004, establishing new tariffs and premiums for each kind of facility covered and incorporating renewable energy, waste to energy and cogeneration plants into the special regime. While previous regulations allowed alternative energy producers with a capacity of at least 50megawatts to either accept price regulation or to sell electricity at market value with the help of subsidies, the new decree guarantees producers a variable subsidy adapted to changes in the market value of electricity. Guarantees for processing new applications: The decree provides that those requesting new production facilities in the special regime must present a guarantee for an amount equivalent to Eur 500 per kW for the photovoltaic facilities or Eur 20 per kW for all other facilities. Hybrid plants: in order to guarantee a more efficient use of the plants and to encourage their development, the new Royal Decree permits hybridization (for example, that a thermoelectric solar plant use biomass when there is no sun or a biomass energy plant burn forest residues when supplies are low). Facilities holding a certificate for the definitive start-up of service before 1 January 2008 that opt to transfer, before 1 January 2009, electricity to the system in return for a regulated tariff will continue to be covered by Royal Decree 436/2004 for the lifetime of that facility. Facilities holding a certificate for the definitive start up of service before 1 January 2008 that opt to sell, before 1 January 2009, energy on the market will also continue to be covered by Royal Decree 436/2004 - until 31 December 2012. Facilities using solar energy as raw material, however, are exempt from these exceptions. Finally, the decree seeks to contribute to Spain's efforts to achieve its 2010 national target for the promotion of electricity from renewable energy under EC Directive 2001/77/CE. Table 9: Plants that mainly use fuel farming biomass residues

43

VEGETATION WATER AND POMACE Norms on industrial discharge: With law n°574, 11th November 1996 (Official Journal n° 265, 12th November 1996) the agronomic use of these by-products is allowed on the ground of their particular organic and inorganic composition that confers them important effects on chemical and structural composition of soils improving their fertility. Such use has to be authorised each time by the competent public authority on the ground of simple documentation but subordinate to limitations, verifications and possible sanctions in order to avoid any fraudulent activity that can pollute water tables. Technical aspects of fertirrigation according to the law 574/96

• maximum tolerance limit for soils: 50 m3/ha/year for vegetable water deriving from traditional mills; 80 m3/ha/year for vegetable water deriving from centrifugal extraction;

• possibility for the Mayor of any municipality of modifying those limits or suspending fertirrigation in case of environmental risk;

• submission of the agronomic report to the Municipality at least 30 days before the spreading. The report has to be written by an expert technician and has to cover topics such as the characteristics of the soil, the time and means of spreading;

• uniform spreading in order to avoid surface runoff;

• it is forbidden to spread vegetable water on soils located within 300 metres from drinkable water basins and/or 200 metre from villages or garden crops or water tables superficial (within 10 metres) or flooded, icy or snowy soils.

The legislative decree n° 152, 11th May 2000 (updated text published on OJ n° 246, 20th October 2000) regards the protection of waters from pollution and applies the European directives 91/271/CEE (treatment of storm sewage) and 91/676/CEE (protection of waters from agricultural pollution caused by nitrates). Article n° 38 (agronomic use) arranges that the competent Ministries issue a specific decree containing the criteria and the technical rules to which the Regions would have to adhere in order to deal consistently with the activities of agronomic use deriving from law 574/96. Such decree, up to now, has not been issued yet. Norms on non dangerous waste disposal:

• D.Lgs. n.152/2006 promotes the energy use of residues, especially from biomass only mechanically treated.

• DGR n. 848/2007 specifies criteria for agronomic use.

• If waters are not disposed nor spread on land, they have to be considered as waste. Norms on fertilizers:

• Virgin pomace from traditional mills can be used as fertiliser. Norms on pomace (dry or virgin) reuse

• DM 05/02/98 dry pomace is considered non dangerous waste that can be used as fuel.

• D Lgs 387/2003: determines what has to be considered “Biomass” (agricultural residues): i.e. any agricultural residue (or forest) which has only undergone mechanical processes

• D lgs 152/2006 determines the characteristics of dry pomace (Table 10) to be used as fuel

EXHAUSTED POMACE

44

With the legislative decree n° 22, 5th February 1997 (the so called Ronchi decree) (Ordinary Supplement n° 33 to OJ n° 38, 15th February 1997) this by-product of pomace extractors is defined as a special but not dangerous waste destined to energy recovery through combustion. Such definition obliges the owners of this by-product to the respect of specific administrative and technical bonds. The decree 5th February 1998 puts such by-product among those for which it is possible to use simplified procedures for their recovery, in compliance with the Ronchi decree. The Prime Minister’s decree 12th July 1990 (Ordinary Supplement n° 176, 30th July 1990) gives the guidelines for the control of pomace extraction plants emissions and fixes their minimum values. As a consequence, Puglia region, the most productive of all Italian regions, with provision n° 7, 22nd January 1999 completes this discipline on pomace extraction plants emissions, in its own territory. As far as the legal limits for phitosanitary products residue and aromatic poly-cyclical hydrocarbons in pomace olive oil are concerned, they are fixed in two decrees of the Ministry of Health of 20th November 2001 (OJ n° 25, 30th January 2002) and 18th September 2001 (OJ n° 25, 27th September 2001). According to the Italian Court for Correction of Errors, Sentence 3rd October 2003, n. 37562, vegetable water resulting from physical processing of olives is not to be considered as a waste when during oil extraction no chemical aids have been employed apart from additional water used either to diluting olive paste or washing machinery. The last word has been therefore said about the meaning of “waste” which according to article 6, clause 1, letter a) of the legislative decree 5th February 1997 (the so called Ronchi's Decree) cannot be applied to goods, substances and materials which objectively and unequivocally are destined to be recycled and therefore will not be abandoned.

Table 15: The characteristics of dry pomace to be used as fuel

Characteristics Measure Min/max

Ashes % (m/m) <4% humidity % (m/m) <15% N-esano mg/kg <30 Clorured organic solvents not present *

Low heating value kcal/kg >4.000 MJ/kg >16,747

• Regional Energy Plan: promotes the energy form biomass to reach a 7% RES in 2010 in Liguria.

• Regional deliberation 1058/2005 defines dry pomace as “green biomass”

• Regional Law 20/2007 states that biomass plant <35kWth do not need any approval. Beyond that limit, they need the Provincial authorization

The evolution of the institutional framework for RES:

The beginning of RES entry into Greece was Law 1559/1985 "Regulation of issues of alternative forms of energy and specific issues of power production from conventional fuels and other provisions" (Official Gazette A 135) under which the PPC, leading the way with RES, installed 24 MW whereas

45

local government organisations confined themselves to a meager level of 3 MW until 1995 and the private sector was left out of the scene entirely. In spite of the small outcome, the effort showed the strengths and weaknesses of the sector and in particular the initial failures paved the way for more mature implementations. Law 2244/1994 "Regulation of power generation issues from renewable energy sources and conventional fuels and other provisions" (Official Gazette A 168) modelled on the pattern of the German legislative document ushered in the RES era. The Law established for the country’s interconnected system fixed sale rates for renewable energy at a level equal to 90 percent of the medium-voltage, general use tariff and made it obligatory for the PPC to buy that energy. For the reimbursement of the capacity part, a scale pricing system was introduced according to the type of RES plant in terms of time availability at nominal capacity. Roughly speaking, the capacity part merely augmented the energy earnings by a small percentage of some 6.5 percent so that the final rate in 2006 corresponded to 0.07287 Euro/kWh. In the islands that are not connected to the mainland’s interconnected system, the pricing was based on 90 percent of the low-voltage, household rate and corresponded in the same year to 0.08458 Euro/kWh and no capacity reimbursement was provided. Law 2773/1999 for the liberalisation of the electricity market maintained the favorable pricing regime for RES by also placing emphasis on priority access to the grids. Law 2941/2001 "Simplification of procedures for establishing companies, licensing Renewable Energy Sources plants, regulation of issues of the company GREEK SHIPYARDS S.A. and other provisions" (Official Gazette A 201), coped successfully with the issue of RES installation in forests and scrublands by including provisions upheld and ruled as constitutional by the Council of State, Greece’s Supreme Administrative Court. Further more, this Law filled some important gaps in the legislative fabric and also attempted to deal the licensing process pathogenesis a thorough blow. On the regulatory level, specially for RES two joint ministerial decisions were issued, namely decision oik.104247/EYPE/YPEXODE/25.5.2006 "Procedure of preliminary, environmental assessment and approval of environmental terms of power plants using renewable energy sources according to article 4 of Law 1650/1986 as replaced with article 2 of Law 3010/2002” (Official Gazette B 663) and decision oik.104248/EYPE/YPEXODE/25.5.2006 “Content, supporting documents and miscellaneous data of preliminary studies of environmental impact assessment, environmental impact assessment studies and appurtenant environmental studies of power plants using renewable energy sources” (Official Gazette B 663) in order to be adjusted the overall licensing of RES facilities to the regime of environmental consensus. Among the regulations introduced, worth mentioning is the restriction of the number of consenting authorities to the absolute minimum necessary, the establishment of short-cut deadlines, the inactive lapse of which will allow the authority in charge of environment permitting to consider as positive the lacking intermediate approvals and opinions of other bodies and generally the streamlining of the sequence of the intermediate consents in the spirit of Directive 2001/77/EC article 6. Also, worth of being mentioning is the joint ministerial decision D6/F1/oik.19500/ 4.11.2004 (Official Gazette B’ 1671) by virtue of which small-scale RES plants were shifted to zero-impact level in order to make their integration possible into towns and settlements. Today the RES deployment regime is governed primarily by Law 3468/2006 “Generation of electricity from renewable energy sources and through high-efficiency co-generation of electricity and heat and miscellaneous provisions” (Official Gazette A’ 129). The text of the law along with its circular D6/F1/oik.21691/30.10.2006 are posted on the Ministry of Development website (http://www.ypan.gr). Policy aspects for the biomass handling in Greece:

46

Sanitary disposition Ε1β/301/1964 “For collection and waste pre-treatment”. This aspect describes technical directions in waste pre-treatment and gives the main directions in sanitary rubbish burial in Greece. Directive 75/442/EC of 15/7/1975 for waste, and the correspondent Greek policy. Directive 2000/76/EC, 4/12/ 2000, in order how to burn rubbish without environmental pollution. Ministerial decision 69728/824/96 "Policies for the handling in solid waste". The non dangerous waste handling is defined by the ministerial decision 69728/824/96. This rule marks that authorities which will manage the administration of the non toxic rubbish policy are the following:

- Reducing and prevention from the produced quantities using sustainable technologies. - Waste development with recycling, reusing or other procedure in order to produce

secondary raw material. - Energy waste development.

Ministerial decision 114218/97 (OGG 1016/Β/17.11.97) in order to get a main frame direction and generally programmes in solid waste handing. Ministerial decision 113944/97 (OGG 1016/Β/17.11.97) which has to do with the National Policy about the handling of solid waste. EC Directive 2000/76 (28/12/2000), for the waste incineration. Ministerial decision 50910/2727/2003 (OGG 1909/Β/2003) "Rules for the pre-treatment of solid waste. National and Regional handling plans". The main purpose of this ministerial decision is to set diachronic targets for the rubbish management in the whole national area in order to:

A. Reduce the waste production. B. Extend and modernisation in the collection and carriage network. C. Develop products which are contained in solid waste and to get energy from them. D. Reduce the bio fraction of solid waste which are going to be buried. E. Get the best environmental solution, for the part of the waste which can not be

elaborated, to put them in places Sanitary Burial. F. Repair environmental damages in places which have been polluted from solid waste.

Energy policy targets in the Republic of Slovenia are set out in the Resolution on the National Energy Programme (OJ RS, No. 57/04). There are two targets from the sphere of efficient energy consumption and renewable sources of energy, divided into a number of sub-targets. Raising the share of renewable sources of energy in the primary energy balance from 8.8 % in 2001 to 12 % by 2010 and targets in individual spheres: - increasing the share of renewable in the supply of heat from 22 % in 2002 to 25 % by 2010, - raising the share of electricity from renewable from 24,4 % in 2006 to 33.6 % by 2010, - 97 % of all electric energy from RES in the 2006 was produced in hydroelectric stations. - ensuring up to 2 % share of bio fuels for transport by the end of 2007. Increasing the share of electricity generated from renewable sources of energy to 33.6 % of gross electricity generated by 2010 will require the inclusion of all types of power plants using renewable

47

sources, from large wind farms to micro solar power plants. The targets of the share of electricity from renewable in the Republic of Slovenia do not at first glance appear high. Taking into account the rapid growth in electricity consumption in the Republic of Slovenia, however, these targets are extremely high.

Strategy of energy development of Republic of Croatia is accepted in March 2002. Energy legislation

include several acts (NN 68/01, 177/04, 76/07) Nevertheless regulations and state authorities are vague concerning olive residues management. OMWW treatment is regulated by Water management legislation but according the Croatian legislations, pomace generated by the production of olive oil is not a waste and as such is not referred in the Official Catalogue of Waste where a proper treatment for every waste is indicated. So, it could be treated as a waste or it could be used as a row material. If it is considered as a waste authorized organization should make physical-chemical analyses of waste and define the proper waste treatment. If it is not considered as a waste, the Ministry of Environmental Protection, Physical Planning and Construction recommend its usage as an animal feed supplement, natural organic fertilizer or solid biofuel. Ministry of Agriculture, Forestry and Water management concerns of its treatment as an animal feed or fertilizer and Croatian Government County Offices regulate its treatment in energy purposes. The lack of common policy on olive waste processing is evident in Croatia. Regarding to expected accession of Croatia to the EU, national legislative is in the process of harmonising with EU legislation.

48

8. Technological Equipment & Costs

Remarks:

All prices are exclusive of VAT. All these stoves are not only suitable for burning exhausted pomace or pits but for other type of biomass as well.

GREECE

Table 16: Economic comparison among energy sources

PRICE

THERMAL

EFFICIENCY COST OF ENERGY PRODUCED

DIESEL 0,70 €/lt

0,06 €/kwh 85% 0,070 €/KWH

PELLETS 0,35 €/kg

0,067 €/kwh 80% 0,084 €/KWH

WOOD 0,12 €/kg

0,026 €/kwh 70% 0,037 €/KWH

EXHAUSTED

POMACE

0,05 €/kg 0,012 €/kwh

75% 0,016 €/KWH

Table 17: Typical cost per household

Heating area Pellets ammount oC Pellet cost

(€)/week

Boiler Cost (€) Stove cost (€)

120 m2 200Kg/week 22 34 3.000 1.500

Figure 30: storage-feeding and burning system

49

Figure 31 : Boiler “Mile” type

Figure 32: Boiler “Mile” with componets

1. NS 100 control panel

2. Reception point of the coontrol panel's sensitivity instruments 3. Reception point of 3/4" for thermostat of the air dumper (wood

only) 4. Door's handle. 5. Lower door's handle. 6. Dumper door for controlling the air of combustion (wood only) 7. Cleaning door 8. Hot water exit to the radiators 9. Dumper for regulating the chimney's air-flow 10. Chimney's connection point

50

11. Chimney's cleaning door 12. Return of cold water from the radiators 13. Boiler's emptying. 14. Solid fuel insert with cast iron coil 15. Blower for combustion air 16. Boiler's lifting point 17. Insulated with nature-friendly materials, totally asbestos free

Table 18: Greek exhausted-pomace boilers “ΜΙΛΕ Π" for domestic use

TECHNICAL FEATURES-GREEK EXHAUSTED-POMACE BOILERS “ΜΙΛΕ Π" FOR DOMESTIC USE

Type Π35 Π50 Π65 Π80 Π110 Π160 Π210

Energy efficiency

(kcal/hr)

35.000 50.000 65.000 80.000 110.000 160.000 210.000

width (mm) 1380 1380 1380 1380 1380 1550 1700

length (mm) 970 970 970 970 1480 1480 1480

height (mm) 1460 1575 1690 1805 1640 1750 1860

weight (kg) 400 420 440 460 460 460 460

price (€) 4.100 4.310 4.540 4.770 6.050 7.490 8.920

Table 19: Greek exhausted-pomace boilers for industrial use

ENERGY EFFICIENCY -GREEK EXHAUSTED-POMACE BOILERS FOR INDUSTRIAL USE

TYPE OF BOILER WOOD EXHAUSTED POMACE DIESEL PRICE

Kcal/h Kcal/h Kcal/h €

Π806 159.000 200.000 250.000 15.140,00

Π807 202.000 255.000 320.000 15.837,28

Π808 246.000 310.000 390.000 16.530,47

Π809 268.000 340.000 425.000 17.488,37

Π810 290.000 370.000 460.000 19.206,41

Π811 312.000 400.000 495.000 20.168,43

Π812 334.000 430.000 530.000 21.131,48

Π813 356.000 460.000 565,000 22.093,50

Π814 378.000 490.000 600.000 23.053,46

Π815 400.000 520.000 635.000 24.015,48

Π816 422.000 550.000 670.000 24.977,50

Π817 444.000 580.000 705.000 25.940,55

Π818 466.000 610.000 740.000 26.902,57

Π819 488.000 640.000 775.000 27.862,53

Π820 510.000 670.000 810.000 28.824,55

Π821 532.000 700.000 845.000 29.787,60

Π822 554.000 730.000 880.000 30.749,62

Π823 576.000 760,000 915.000 31.711,64

Π824 598.000 790.000 950.000 32.671,60

Π825 620,000 820,000 985,000 33.629,50

Π826 642,000 850,000 1,020,000 34.591,52

Π827 664,000 880,000 1,055,000 35.554,57

Π828 686,000 910,000 1,090,000 36.516,59

Π829 708,000 940,000 1,125,000 37.478,61

Π830 730,000 970,000 1,160,000 38.438,57

Π831 752,000 1,000,000 1,195,000 40.723,11

51

BOILERS FOR HEATING AREA

• BETWEEN 40m2

AND 240m2

PRICE: 4.300-13750€

• BETWEEN 80m2

AND 450m2

PRICE: 6.900-25.300€

• BETWEEN 200m2

AND 800m2

PRICE: 23.200-43.000€

52

• BETWEEN 600m2

AND 1300m2

PRICE: 52.500-86.000€

• BETWEEN 1000m2

AND 2000m2

PRICE: 75.000-130.000€

STOVES FOR HEATING AREA:

• stove for heating area,7 kw, price:1300€

• stove for heating area between 9 kw and 13,5 kw, price: 1500-2100€

• stove for heating & hot sanitary water production 24kw, price: 3300€

53

ITALY

Table 20: Equipment characteristics

Technology capacity €

nut separator 500-1000 kg/h 10000-20000

burner see tables below see below

Burner with boiler see tables below see below

wood pelletizer 7400 ton/y (1400 kg/h if 5280 h/y) 2240000

pomace pelletizer 300 kg/h 95.000

pomace pelletizer 50 kg/h 35.000

Table 21: Transportation costs

1ton = 0,5 €/km VAT incl. Distance < 50 km

1ton = 0,4 €/km VAT incl. Distance <100 km

Table 22: Cost and heating value data

Fuel measure unit € heating power [kcal/kg]

Virgin pomace 1800

Depleted (exhausted) pomace 100 kg 2 4000

Wood pellet (to final users) 100 kg 27-40 4200

Pomace pellet 100 kg 14 4000

Nut 100 kg 15 4750

Table 23: Gross Energy data

Fuel [kcal] 100 kg [MWh] 100 kg efficiency ratio net energy

(MWh)

€/MWh final

use

Virgin pomace 180000,00 0,21 0,00 0,00 na

Depleted pomace 400000,00 0,46 0,80 0,37 5,39

Wood pellet (to final

users)

420000,00 0,49 0,85 0,41 80,89

Pomace pellet 400000,00 0,46 0,80 0,37 37,72

Nut 475000,00 0,55 0,85 0,47 32,03

Notes

75% of pellet producers are based in North Italy 4.656.800 kg of wood pellets sold in Liguria in 2006 of which

64% in Imperia

54

Table 24: “K22” Series automatic burners

K2202 E K2204 E K2206 E K2208 E K2210 E K2213 E K2218 E

Nominal Power kW 20 46 69 93 116 151 209

Allowable max pressure bar 3 3 3 3 3

Allowable max temperature ° C 85 85 85 85 85

Volume l 64 116 158 200 240

Fuel wood pellet & agricultural residues

Application field Agriculture/industry/Civil buildings

Burner type

Automatic regulation system of the temperature

Automatic switch on / switch off

Heating & hot sanitary water production

Price (VAT excluded) € 4650,0 4950,0 5500,0 6350,0 7450,0 15000,0 17750,0

Power cost €/kW 232,5 107,6 79,7 68,3 64,2 99,3 84,9

Figure 33

Table 25:”K22” Series manual burners

K2202 K2204 K2206 K2208

Nominal Power kW 20 46 69 93

Allowable max pressure bar 3 3 3 3

Allowable max temperature ° C 85 85 85 85

Volume l 64 116 158 200

Fuel wood pellet & agricultural residues


Burner type Automatic regulation system of the temperature

Manual switch on / switch off


Price (VAT excluded) € 3800,0 4150,0 4750,0 5500,0

Power cost €/kW 190,0 90,2 68,8 59,1

55

Figure 34

Table 26: ”KN” Series automatic burners

KN2002 KN2004 KN2006 KN2008 KN2010

Nominal Power kW 20 46 69 93 116

Allowable max pressure bar 3 3 3 3 3

Allowable max temperature ° C 90 90 90 90 90

Volume l 50 116 158 200 240

Fuel minced agricultural residues (no pellet) - pomace





Price (VAT excluded) € 3250,0 3500,0 4100,0 4900,0 6000,0

Power cost €/kW 162,5 76,1 59,4 52,7 51,7

Figure 35

Table 27:Burner accessories

Accessories € Power Range Per series

joint screw (if an external fuel tank has been provided)

1.900 23 - 116 kW KN - K22xx - K22xx E

3.150 151 - 267 kW

pressure metering sensor/temperature metering sensor/security vessel/expansion vessel

1.500

K22xx - K22xx E

56

Table 28: “K24” Series burners

K 2404 E K 2406 E K 2408E K 2410E K2413 E


Allowable max pressure bar n.a n.a n.a n.a n.a

Allowable max temperature ° C 85 85 85 85

Volume l n.a n.a n.a n.a n.a

Fuel wood pellet /pomace

Application field agriculture/industry/greenhouses

Burner type warm air blower

Automatic regulation system of the temperature


ONLY for heating use

Price (VAT excluded) € 5300,0 6200,0 7400,0 9650,0 18300,0

Power cost €/kW 115,2 89,9 79,6 83,2 121,2

Figure 36

Table 29: “K25” Series burners

(*) K 2504 E K 2506 E K 2508

E

K 2510

E

K2513 E


Fuel chips/wood pellet/pomace

Price (VAT excluded) € 8900 9850 11950 16500 34000

Power cost €/kW 193,5 142,8 128,5 142,2 225,2

Burner type generatore aria calda (*)only for demand

57

Figure 37

Table 30: “C.B.S.M” Series burners

C.B.S.M 400 C.B.S.M 600 C.B.S.M

800

C.B.S.M

1000

C.B.S.M

1000


Allowable max pressure bar n.a n.a n.a n.a n.a

Allowable max temperature ° C n.a n.a n.a n.a n.a

Volume l n.a n.a n.a n.a n.a

Fuel pellet consisting of various types of agricultural residues

heat exchanger for hot

sanitary water production

optional optional optional optional optional


Manual or auto switch on / switch off


Efficiency > 80 % > 80 % > 80 % > 80 % > 80 %

Price (VAT excluded) € 4800 5200 6100 7000 11300

Power cost €/kW 104,35 75,36 65,59 60,34 64,94

Figure 38

58

Table 31: “GS” Series burners

GS 36 GS 51 GS 81

Nominal Power kW 40,6 58 92,8

Allowable max pressure bar n.a n.a n.a

Allowable max temperature ° C n.a n.a n.a

Volume l 100 125 200

Fuel wood pellet / pomace pellet/ nut



optional optional optional




Efficiency > 85 % > 85 % > 85 %

Price (VAT excluded) € 8920,0 9690,0 10680,0

Power cost €/kW 219,7 167,1 115,1

Figure 39

Table 32: Burner accessories

GS 36 GS 51 GS 81

Hot sanitary water production coils € 350,00 350,00 500,00

59

Table 33:”Biomassa 34” type burner

Biomassa 34

Nominal Power kW 34

Allowable max pressure bar 2,5

Allowable max temperature ° C n.a

Volume l n.a

Fuel pellet consisting of various agricultural residues/

pomace/nut



n.a



Heating & hot sanitary water production (if an external hoarder has been installed)

Efficiency 90%

Price (VAT excluded) € 5.600,00

Power cost €/kW 164,71

Table 34: “Biomatic” Series burners

(**) Biomatic 20 + Biomatic 30 + Biomatic 50 +

Nominal Power kW 22 32,9 54,9

Allowable max pressure bar 1,5 1,5 1,5

Allowable max temperature ° C 100 100 100

Volume l 140 n.d 115

Fuel wood pellet wood pellet wood pellet

heat exchager for hot sanitary

water production

included included included

Burner type automatic switch on

Automatic flame regulation system

4-ways valve

semi-automatic cleaning system


Efficiency > 91% > 91% > 91%

Price (VAT excluded) € 9.292,00 12.254,00 13.595,00

Power cost €/kW 422,36 372,46 247,63

(**)flux metering sensor / plate heat exchanger for hot sanitary water / circulating pump included

Figure 40

60

Figure 41: Biomatic burner

Table 35: Accessories costs

Accessories

Ashes' automatic extractor € 1.179,00

jointed screw € 1.438,00

external pellet storage tank (200 kg) € 665,00

external pellet storage tank (500 kg) € 1.143,00

thermal hoarder (1100 l) € 4.612,00

thermal hoarder (1840 l) € 5.712,00

61

Table 36: Animax Turbomatic burners

Arimax Biojet Turbomatic 110 Arimax BIO

Nominal Power kW 80 110 120

Allowable max pressure bar 1,5 3 1,5

Allowable max temperature ° C 120 95 120

Volume l 370 300 460

Fuel pellet / nut pellet pellet

Price (VAT excluded) € 24800,00 24551,00 31700,00

Power cost €/kW 310,00 223,19 264,17

burner, fuelling screw, electrical control and regulation board, extracting screw (from silos)

Table 27: Accessories costs

Accessories

Thermal hoarder (3000 l) € 2400

Boiler (200 l) € 1278

Slovenia

Table 38: Slovenian storest burners

Slovene Stoves representatives

Power [kW] Component Price

4-10 Stove+burner 5.895,00




20 Stove 2.010,52

30 Stove 2.613,60

40 Stove 2.928,24

10-22 Burner 2.412,62

10 Stove+burner 7.875,00





Table 39: Slovenia Stores burners

Slovene stove producer

Power [kW] Component Price

7,5-25 Stove+burner 5.440,00


22,5-75 Stove+burner 8.730,00

62

30-100 Stove+burner 10.750,00

37,3-125 Stove+burner 12.040,00



8-29,4 Stove+burner 3.417,75


61-100 Stove+burner 15.000,00

87-150 Stove+burner 24.000,00



800 app. 160.000,00

1.000 app. 220.000,00

Table 40: Cost data

Pellets

Approximate price of pellets 156,75€/T - 176,00€/T, without transport.

Table 41: Pellet press cost

Component Capacity Price (€)

pelleting press 2T/h app. 150.000

all plant 2x 3T/h app. 9.000.000

Croatia

Table 42: Croatian representatives of pellet stoves

Power [kW] Components Price (EUR)

26 stove 718

32 stove 788

23 stove 621

41 stove 820

12,5-25 stove 3.745

45 stove 4.574

25 stove 4.816

47 stove 7.826

350 stove + burner 86.611





63

Table 43: Croatian representatives and producers of pomace pellet stoves

Power [kW] Components Price (EUR)

25 Stove+burner 3.228

boiler 462

35 stove with boiler for central heating 4.014

Table 44: Cost data

Pellets

190-210 EUR/t without transport

Table 45: Accessories for pelleting

Component Capacity Price (EUR)

pelleting press 200-700 kg/h 15.300

pelleting press 400-1500 kg/h 20.700

64

9. Annex

Statistics of energy consumption, ranked by country.

Title: Electricity consumption by country in 2005.

Definition: Total electricity consumed annually plus imports and minus exports, expressed in terawatt-hours

Source: CIA World Fact book

Country: Amount: Bar Graph:

Italy 303.8 Spain 241.8 Greece 53.5 Croatia 16.53 Slovenia 13.71

Title: Oil consumption by country in 2006.

Definition: Quantity consumed per day, in thousands of barrels Source: BP Statistical Review of World Energy June 2007

Country: Amount: Bar Graph:

Italy 1793 (2005: 1819 , –1.1% ) Spain 1602 (2005: 1619 , –0.9% ) Greece 451 (2005: 432 , 4.7% )

Title: € per litre Diesel

Definition:

Average amount in euro per one litre of Diesel. Incl. taxes & duties. In brackets: price excl. taxes & duties. Effective: May 30, 2008

Source: Euro-super 95 and Diesel: DG-TREN, Electricity and Gas: Euro Stat, GAS USA: Dept. of energy (DOE)

Country: Amount: Italy 1.49 ( 0.82) Greece 1.37 ( 0.84) Spain 1.31 ( 0.82) Slovenia 1.26 ( 0.75) Croatia 1.38

Title: € Per kWh electricity.

Definition: Average amount in euro per one kilowatt-hour of electricity for domestic consumers. Based on an annual consumption of 3500 kWh (30% during night time).Incl. taxes & duties. Effective: December, '07

Source: Euro-super 95 and Diesel: DG-TREN, Electricity and Gas: Euro Stat, GAS USA: Dept. of energy (DOE)

Country: Amount: Italy 0.234 Spain 0.123 Slovenia 0.113 Greece 0.073

Croatia 0.098

65

10. References

1. Biomass fuel supply chains for solid biofuels, EUBIONET2, IEE project

2. Biomass supply chains of Megalopolis district heating plant, Fact sheet 15 – Greece, EUBIONET2, IEE project.

3. By-Product Reusing from olive and olive oil production, TDC Olive network

4. Electronical Technical Transfer Olive Oil Network (www.e-toon.net)

5. Fuel Analyses and Thermo chemical Processing of Olive Residues AYHAN DEMIRBAS A; NADIR ILTEN A SELCUK

6. Herz (www.herz-feuerung.com)

7. Importance of olive-oil production in Italy, by G. FONTANAZZA.

8. Olive-oil production in Italy by PAUL VOSSEN

9. Olive-oil production in Greece by PAUL VOSSEN

10. Olive stone: a source of energy generation and a suitable precursor for activated carbon production S. ROMÁN, J. F. GONZÁLEZ1, J. M. ENCINAR

11. Olive Cake Supply Chain in Andalusia, Spain, Fact sheet 32 – Spain, EUBIONET2, IEE project

12. Possibilities of using olive kernel wood for power generation on Crete – Greece, by JOHN VOURDOUBAS

13. Production of pomace olive oil, By PEDRO SÁNCHEZ MORAL AND Mª VICTORIA RUIZ MÉNDEZ.

14. Rotary Drying of Olive Stones: Fuzzy Modelling and Control, by N. C. TSOURVELOUDIS, L. KIRALAKIS

15. Spanish Olive-oil production by PAUL VOSSEN

16. Utilisation of olive husk in energy sector in Cyprus, FOKAIDES, P., TSIFTES, K.

The sole responsibility for the content of this [webpage, publication etc.] lies with the authors. It does not necessarily reflect the opinion of the European Union.

The European Commission is not responsible for any use that may be made of the information contained therein.

Date post:	30-Jan-2020
Category:	Documents
Upload:	others
View:	0 times
Download:	0 times

Market of Olive Residues for Energy - European Commission · 2014-08-11 · 5 1. Olive Oil...

Documents