SUSTAINABLE CITIES: BIOGAS ENERGY FROM...

AGAMA Biogas (Pty) Ltd

The Green Building, 9b Bell Crescent Close, Westlake Business Park, 7945, South Africa

Tel: +27 (0)21 701 3364 • Fax: +27 (0)21 701 3365 • [email protected] • www.agama.co.za

Registration Number: 2008/018166/07

SUSTAINABLE CITIES: BIOGAS

ENERGY FROM WASTE

A FEASIBILITY STUDY AND GUIDELINES FOR IMPLEMENTING

BIOGAS FROM WASTE PROJECTS IN MUNICIPALITIES

GUIDELINES REPORT

July 2009

SOUTH AFRICAN CITIES NETWORK

Sustainable Cities: Biogas Energy from Waste: Guidelines Report Page i

Executive Summary

Introduction

This study explores biogas energy from waste opportunities in municipalities as a solution to address both liquid sewage and solid waste management problems. This Toolkit - comprising a technical report, a guidebook and a feasibility model - was commissioned by the South African Cities Network (SACN) to support their ongoing activities within Municipalities in South Africa addressing efficiency, energy and waste issues. These feasibility and planning tools are provided for energy from waste strategies that link up integrated waste management, sanitation planning, energy crisis resilience and climate change mitigation responsibilities.

The Toolkit is aimed at Municipal officials that are concerned with more sustainable measures to cope with the ever-increasing flows of municipal solid waste, and sewage, amongst other biowastes. The primary output, based on a range of selections made by the user, is a summary of the financial attractiveness of a given project scenario. The Toolkit was prepared by AGAMA Biogas and completed in July 2009, and presented at a seminar held in the City of Cape Town on 17 July 2009.

This executive summary outlines the guideline report as well as the technical report and model.

The guideline report is focussed on guidelines for planning and implementing municipal biogas systems including the current legislative environment and financial opportunities for biogas energy projects, as well as recommendations relating to policy for biogas energy projects. The technical report inter alia

• discusses biogas technology and its applications;

• looks at case studies of operating plants;

• presents waste data from the larger municipalities translated into a potential energy figure; and

• presents information on using the generic feasibility model, which allows for any potential biogas energy from waste project to be adequately scoped.

Sustainability: the rationale for this study

The World Commission on Environment and Development defines sustainability as a means of undertaking forms of progress that meet today’s needs without compromising the ability of future generations to meet theirs. As a society we need to ensure that our actions are sustainable from economic, environmental and social perspectives; thus, focusing on the lifecycle costs of a system (not just the capital or running costs), ensuring that the impact on the local and global environment are at worst neutral, and ensuring that we have the systems and capacities in place to operate our interventions into the future.

In South Africa the flow rates to centralised wastewater treatment works (WWTW) and the generation of municipal solid waste (MSW) are increasing due to the urbanising trend and population growth within the country. The impacts of this increase and lack of proper landfill and WWTW management are a shorter landfill life, increased methane emissions from landfills and WWTW and increased pollution of water and ground. This is not sustainable.

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An alternative to centralised services provision of waste management is to rather deal with these wastes further upstream, and even on-site, at the point of generation. A perfect example of this would be on-site composting of the organic fraction of municipal solids waste (OFMSW), and installation of an on-site sewage treatment system. Combining the two waste flows into one stream for co-treatment is a further opportunity. To this end, this work is focussed on on-site and mid-stream interception of wastes and optimising their co-treatment.

Biogas and biogas technology applications

Anaerobic Digestion is a process of decay of non-lignocellulosic biomass through the activity of anaerobic bacteria in the absence of oxygen. There are three micro-organisms (Hydrolytic, Acetogenic and Methanogenic) that break the complex chains to short-chain fatty acids and gasses then converted to acetic acid with further gases and finally biogas.

The energy output varies and is dictated by the volume of the biogas produced and the percentage methane in that volume. Carbohydrate rich feedstock results in about half methane, half carbon dioxide, whereas feedstock with high nitrogen (such as sewage sludge) produces nearly two-thirds methane. While the volume of biogas possible from a unit of various feedstocks is fixed, the rate of production (thus the digester size) is affected by the temperature and mixing within the digester.

Biogas Technologies

In general the fermentation reactor can be wet (up to 15% dry) or dry (between 25 and 50% dry). Wet fermentation technology typically involves the use of a reactor tank usually or often continuously mixed by impellers, recirculating pumps or recirculated biogas injection. The reactors are sometimes heated.

From left: Dome (wet), Plug-Flow (wet), Chamber (dry): [AGAMA, www.omafra.gov.on.ca, Bekon]

Covered lagoon digesters are also used for wet fermentation and are typically non-heated. Dry fermentation has been successfully demonstrated in a floor heated concrete chamber that seals the biogas in and air out. Other types of dry fermentation are ‘bag type’ or ‘immersion liquid storage vat’. The dry feedstock is introduced into the chamber in batches by means of a front-end loader or similar. Low sulphur output of dry fermentation means that less gas scrubbing is required for electrical generation.

The biogas characteristics of wet and dry fermentation are shown below:

Component Average Wet Percentage Range Dry Percentage

Methane (CH4) 60% 40 - 75%

Carbon Dioxide (CO2) 35% 25 - 55%

Water Vapour (H2O) 1.67% 0 - 10%

Ammonia (NH4) 1.67% 0 - 1%

Hydrogen Sulphide (H2S) 1.67% 0 - 1%

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It is possible that dry biomass from OFMSW can be added to a wet fermentation process, or dry sludge from the drying beds or dewatering plant at a wastewater treatment plant could be added to the dry fermentation process.

End Uses of Biogas in Municipal Context

The most direct and simple use of biogas is for household cooking or heating. Additional feedstock is required to be able to supply a group of houses, whose sewage feeds the digester, with enough gas to cook. Scrubbed and purified biogas could feed directly into a natural gas network.

Industries or industrial areas that have organic waste but also require heat for drying, steam production or cooling (in conjunction with an absorption chiller) could achieve integrated resource management with energy from waste.

For electricity generation the biogas needs to be filtered and scrubbed or purified. This would extract water vapour and sulphur which are potentially corrosive compounds to engines, as well as CO2 (which has no energy content), from the biogas. The resulting biomethane could be used as a fuel for gas engines or turbine powering an electrical generator. Another emerging electricity generator from biogas is a fuel cell. In this case the biogas needs to undergo intensive upgrading because H2S and ammonia (NH4) are toxic to the catalysis and have to be completely removed.

500 kW biogas engine (Austria), 1 MW reciprocating biogas engine (USA)

Source: www.bios-bioenergy.at, San Diego Wastewater Treatment Department, USA

It is encouraging to review the emerging technologies such as microturbines and fuel cells and these should not be forgotten when assessing energy from waste facilities. However, in the context of a developing world scenario it may be wiser to choose reciprocating engine technology that is well known, locally maintainable, easily available and proven to be effective.

Algaculture / Aquaculture

The nutrient rich effluent from a biogas digester is well suited to algaculture and aquaculture. Algae are fast growing and can be used as animal feed or fish food (and a possible future food source for humans). The algae can also be seen as an additional feedstock to put back into the digester or for biofuel production.

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Integrated Bio-energy and Waste Management

The figure below shows the options for integrated bio-energy and waste management solutions

Legal framework

Waste in South Africa is currently governed by means of a number of pieces of legislation1, including:

The South African Constitution (Act 108 of 1996) Hazardous Substances Act (Act 5 of 1973) Health Act (Act 63 of 1977) Environment Conservation Act (Act 73 of 1989) Occupational Health and Safety Act (Act 85 of 1993) National Water Act (Act 36 of 1998) The National Environmental Management Act (Act 107 of 1998) Municipal Structures Act (Act 117 of 1998) Municipal Systems Act (Act 32 of 2000) Mineral and Petroleum Resources Development Act (Act 28 of 2002) Air Quality Act (Act 39 of 2004) Waste Act (Act 59 of 2008)

1 For copies of this legislation visit www.polity.org.za/pol/acts/

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Policy Makers' Guide

Policy makers should consider the following with respect to energy from waste:

• Anaerobic digestion (AD) most prominent for biogas production.

• Carbon revenue can make large AD possible.

• Biogas benefits include heat, electricity and fertiliser.

• Integration into effective sanitation goals and free basic alternative energy policy.

• A standard implementation agency is required as well as skills development and capacity building in energy from waste projects.

• Demonstration projects would help pave the way.

• Better waste data collection is required.

• Cumbersome regulatory issues have led to the lack of successful projects.

• Municipal Finance Management Act imposes constraints on public-private partnership.

• Special feed-in tariffs may provide a boost.

Planning a biogas energy project

There are six overall steps in the project development:

1. The project concept is outlined at a basic level, so that the ultimate end point is well defined

2. Thereafter, the project feasibility – which assesses technical, financial and legal factors – is undertaken

3. If the project appears feasible, the project preparation steps can be undertaken

4. This leads to implementation, or project realisation

5. After implementation the biogas energy system is ready for commissioning

6. Thereafter the project moves into the operation and maintenance stage.

Project development stages

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Municipal Waste Data

Definition of waste

The definition of waste as stated by the Waste Act (Act No. 59, 2008) is as follows:

“Waste” means any substance, whether or not that substance can be reduced, re-used, recycled and recovered –

(a) that is surplus, unwanted, rejected, discarded, abandoned or disposed of:

(b) which the generator has no further use of for the purposes of production:

(c) that must be treated or disposed of; or

(d) that is identified as a waste by the Minister by notice in the Gazette and includes waste generated by the mining, medical or other sector, but –

(i) a by-product is not considered waste; and

(ii) any portion of waste, once re-used, recycled, recovered, ceases to be waste

Wastewater

Studies were consulted for wastewater to energy potential is South Africa. The current national wastewater treatment plants process an estimated 7,600 ML/day. Theoretically the potential electricity generation from all the national plants, if AD was utilised, is about 850 MWth or 255 MWe (UCT study). AGAMA Energy conducted an assessment of the six largest metro’s wastewater to energy potential arriving at 31 MW capacity or 263 GWh/a. Another study by PDG looked at the plants in South Africa that are currently utilising AD, that are considered large enough, and calculated the electricity potential from these plants as being about 12 MW and 105 GWh/a.

Solid Waste

AGAMA EfW studies projected that the quantity of solid waste disposed by the six largest municipalities2 in 2004 is about 8 million tonnes with a projected increase to 10 million tonnes in 2010. A total amount of 71,000 TJ/a of net energy content is disposed of at the landfill sites of South Africa’s Metros. This is equivalent to a total electricity generation of 6,000 GWh/a from a capacity of 693 MW of net energy being discarded. This is a theoretical number of all the embedded energy and it does not take into account any energy losses occurring in energy transformation and supply systems, nor infrastructural constraints, and assumes conversion of all of the energy content. If only the organic fraction is considered for the generation of biogas then the six largest metros, where it is more likely that an energy from waste project is feasible (due to scale), about 1,500 GWh/a is possible from about 176 MW of capacity. If a 25% organic waste capture factor were taken into account this would result in 375 GWh/a from 44 MW of capacity.

Summary of Energy Potential in South Africa

Waste Electrical Capacity Electrical Generation

Theoretical

AD of wastewater 31 MW 263 GWh/a

AD of organic solid waste 176 MW 1,500 GWh/a

TOTAL 207 MW 1,763 GWh/a

Realistic

AD of wastewater 12 MW 105 GWh/a

AD of organic solid waste 44 MW 375 GWh/a

TOTAL 56 MW 480 GWh/a

2 City of Johannesburg, Ekhurhuleni, eThekwini, Tshwane, Nelson Mandela Bay, City of Cape Town

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It should be noted that these figures are for large electricity generating plants. There is also an energy from waste potential for smaller plants where the gas is used directly and locally as an LPG replacement for cooking and heating.

Case Studies

Summary of Case Studies

Country South Africa Europe Asia

Plant Cato Manor PetroSA Bran Sands Moosdorf Rayong

Type Hydraulic fixed slab digester with aquaculture

Gas engine electricity generators

Advanced anaerobic digestion

Dry fermentation Mech treatment & anaerobic digester

Feed-

stock

Sewage (70 m3), OFMSW & Chicken litter (~3t max)

Refinery process waste

Sewage OFMSW and yard waste (12,700 t/a)

OFMSW (25,550 t/a)

Size Small (280 m3

digester) Large Large (2.1 ha) Medium

(7 chambers - 4,000 m2)

Medium

CAPEX R1.2 million (min 4 y breakeven)

R30 million R429 million R21 million (estimated)

R31 million

Output & Benefits

13 t/a LPGe (min)

Max: 67 t/a LPGe

34 GWh/a elec (3 x 1.4 MWe),

33,000 t/a CO2

37 GWh/a elec (4.7 MWe),

2 MWh heat,

R21 mil ROCs

5 GWh/a elec (710 kW),

7 GWh/a heat,

3,500 t/a water

5 GWh/a elect (625 kWe),

43,513 t/a CO2

Cost per Output

R92k/t/a LPGe (min)

Max: R18k/t/a

R882k/GWh/a, R7mil/MWe (elec plant only)

R11mil/GWh/a, R91mil/MWe

R4.2mil/GWh/a, R29mil/MWe


Maintenance Low High High Medium High

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Photos and illustrations from the case studies

South Africa – Cato Manor

May 2009 – brick walls with reinforcing progressing [AGAMA Energy]

South Africa – Petro SA

The biogas power building and 1.416 MW Jenbacher gas gensets at Petro SA Source: [www.biothermenergy.com]

Europe, UK - Advanced Anaerobic Digestion, Germany - Dry Fermentation

Bran Sands Waste Water Treatment works and Moosdorf dry fermentation energy recovery plant

Source: [Renewable Energy World, BioFerm Energy]

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Asia (Thailand) – Rayong

1 Bag opener 6 Feed preparation tank 11 Mechanical dryer

2 Drum screen 7 Bioreactor 12 Process water tank

3 Magnetic separator 8 Biogas holder 13 Thermal dryer

4 Fragmentiser 9 Gas engine generator 14 Fertiliser

5 Suspension tank 10 Buffer storage tank

Using the feasibility model

The model is a workbook of 9 spreadsheets including ‘Read Me’, ‘About’, ‘Flowchart’, ‘Feasibility Inputs’ and 5 process sheets with options (e.g. input for waste, post digester, land cost, revenue and site specifics) and an output summary including:

• Biogas production

• Electricity capacity and generation or LPG equivalent • Plant footprint • Capital and Operating cost • Cost

• Revenue and Interest charges

• IRR, NPV and payback The feasibility inputs give financial options (e.g. equity levels, inflation, sale prices, etc) technical options (e.g. generator efficiency, electricity required, runtime, etc) and carbon options (e.g. price, emission factors, CDM costs, etc). An overview of the model is illustrated by the flowchart shown below. In the model the flowchart directs the user to the correct process sheet.

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Acknowledgements

Content credits:

Greg Austin and Alastair Gets from AGAMA Biogas wrote the report and designed the feasibility model.

A reference group of experts provided guidance and advice on the methodology and outputs. In particular, the SACN would like to thank:

Barry Coetzee and Melumzi Nontangana (Solid Waste, City of Cape Town); Prof Harro von Blottnitz (Chemical Engineering, UCT); Peter Lukey (Department of Water and Environmental Affairs); Thembakazi Mali (Saneri)

Production credits:

Project management: Annie Sugrue (EcoSASA)

Photographs: Various (as indicated under the photographs)

Design and layout: AGAMA Biogas

Sadhna Bhana, Supriya Kalidas, Sharon Lewis, Clement Mpurwana, and Astrid Wood from the SACN secretariat provided administrative and programme management support.

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General Disclaimer

This information is provided "as is" and without warranty, express or implied. All warranties with regard to the accuracy, reliability, timeliness, usefulness or completeness of the information contained within this report are expressly disclaimed. All implied warranties of merchantability and fitness for a particular use are hereby excluded.

None of the authors or the Department of Science and Technology shall be liable or responsible to any person or entity for any loss or damage, including special, incidental, consequential, punitive or indirect damages, caused, or to have been caused (including, but not limited to, liability arising out of contract, negligence, strict liability, tort, patent or copyright infringement) directly or indirectly by or from the information or ideas contained, suggested, or referenced in this report or for any errors, misstatements, inaccuracies or omissions in the information or ideas contained in the report.

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Table of Contents

1. Introduction 1

2. Sustainability: the rationale for this study 1

3. Planning a biogas energy project 3

3.1 Outline of biogas energy project development 3

3.1.1 Project conceptualisation 3

3.1.2 Feasibility study 4

3.2 Planning and Preparation 5 3.3 Project implementation 5 3.4 Operation and Maintenance 6

4. Legal framework 6

4.1 Overarching legislation 6

4.1.1 Municipal Systems Act 7 4.1.2 Municipal Finance Management Act 8

4.2 Energy 8

4.2.1 White Paper on Renewable Energy 8

4.2.2 Department of Minerals and Energy 9

4.2.3 National Electricity Regulator and the new Energy Regulator 9

4.2.4 Renewable Energy Feed-in Tariff 9

4.3 Water 11 4.4 Solid waste 11 4.4.1 Integrated Pollution and Waste Management Policy for South Africa 11 4.4.2 National Waste Management Strategy 12

4.4.3 Waste management legislation for South Africa 13

4.4.4 Polokwane Declaration on Waste Management in South Africa 15

5. Policy Makers' Guide 16

6. Case Studies 17

6.1 South Africa 18

6.1.1 Cato Manor 18

6.1.2 Petro SA 20

6.2 Europe (UK - AAD & Germany - Dry Fermentation) 23

6.2.1 UK - Advanced Anaerobic Digestion 23

6.2.2 Germany - Dry Fermentation 24

6.3 Asia (Thailand) - Rayong 27

7. References 30

8. Resources 31

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Acronyms and abbreviations

ABM Area Based Management (eThekwini Municipality)

AD Anaerobic digestion

AAD Advanced anaerobic digestion

CCT City of Cape Town, http://www.capetown.gov.za

CDM Clean Development Mechanism

CER Certified Emission Reductions

DEAT Environmental Affairs and Tourism

DME Department of Minerals and Energy (now split into two departments)

DS Dry solid

DWAF Department of Water Affairs and Forestry (now the Department of Water and Environmental Affairs)

ECA Environment Conservation Act

ECAA Environmental Conservation Amendment Act

EfW Energy from Waste

FIT Feed-in Tariff

GHG Greenhouse gas

LPG Liquefied Petroleum Gas

MFMA Municipal Finance Act

MSW Municipal Solid Waste

NEMA National Environmental Management Act

NEPO National Energy Policy Office (Thailand)

NERSA National E Electricity Regulator of South Africa

NSA National Services Act

NWA National Water Act

NWMS National Waste Management Strategy

OFMSW Organic Fraction of Municipal Solid Waste

RE Renewable energy

REFiT Renewable Energy Feed-In Tariff

REPA Renewable Energy Purchasing Agency

ROC Renewable Obligation Certificate (UK)

UCT University of Cape Town

UNFCCC United Nations Framework Convention on Climate Change

VS Volatile solid

WMIS Waste Management Information System

WRC Water Research Commission

WWTW Waste Water Treatment Works

Sustainable Cities: Biogas Energy from Waste: Guidelines Report Page 1

This report comprises the GUIDELINES that assist the reader in planning and implementing biogas energy from waste projects.

1. Introduction This study explores biogas energy-from-waste opportunities in municipalities, and presents the information through a set of guidelines on the generation and use of biogas from municipal waste, as a solution to address both liquid sewage and solid waste management problems.

The project objective is to provide municipalities with feasibility and planning tools for energy-from-waste strategies that link up integrated waste management, sanitation planning, energy crisis resilience and climate change mitigation responsibilities.

Hence, there are two distinct outputs:

• A technical report that (i) analyses waste data streams in a sample set of municipalities; (ii) explains the development of the biogas feasibility model; and (iii) establishes a set of key feasibility benchmarks for municipal biogas systems.

• A set of guidelines for municipal leaders and officials on how to design, assess, plan, build and operate energy-from-waste systems through municipal biogas operations.

The information presented in this report is focussed on the latter output: guidelines for planning and implementing municipal biogas systems. The report also includes a comprehensive section covering the current legislative environment and financial opportunities for biogas energy projects. Recommendations relating to policy for biogas energy projects conclude this report.

The focus of these guidelines is on decentralised energy-from-waste plants. The design approach for sewage energy-from-waste plants is on low tech, small scale and a combination of the primary settling pond with an anaerobic digester. In this approach the digester retains solids for hundreds of days as a settling tank would do, whereas the effluent, after about five days, flows to secondary treatment. The digester is sized on the feedstock loading to prevent wash-out.

2. Sustainability: the rationale for this study There are many definitions of what sustainability means and what actions to achieve it might comprise. Perhaps the best known statement or definition is that of the World Commission on Environment and Development: sustainability means undertaking forms of progress that meet the needs of the present without compromising the ability of future generations to meet their needs. In practice, we as a society need to ensure that our actions are sustainable from economic, environmental and social perspectives. This means that we need to need to focus on the lifecycle costs of a system (not just the capital or running costs), we need to ensure that the impact on the local and global environment are at worst neutral, and we need to ensure that we have the systems and capacities in place to operate our interventions into the future. And, of course, the interventions themselves have to be acceptable and appropriate to our society and communities within it.

In South Africa, we are faced with the fact that flow rates to centralised waste water treatment works (WWTW) are increasing due to the urbanising trend within the country. The generation of municipal solid waste (MSW) in South Africa is increasing at a rate of up to 7% [1]. These facts have some of the following unintended impacts:

• Our landfill sites have a much shorter lifetime than their planned lifetime. Landfill site lifetimes are measured in terms of available landfill volume, or


airspace, and the faster this airspace it filled the quicker the available volume is filled

• Biogas emitted into the atmosphere from these landfill sites is also increasing faster than anticipated. Although current thinking by government, and planning by the private sector, would lead to capturing this biogas, the status quo (or baseline situation) is that our landfills are emitting enormous quantities of methane gas into the environment (see BOX 1 for info on methane gas)

• The situation at WWTWs is of extreme concern, with varied reports indicating that the plants are not properly managed or maintained, and are not coping with the increased loading rates. The net effect of this is non-DWAF compliant water being discharged to the environment, enormous levels of pollution in our rivers, with resulting loss of oxygen availability to our aquatic flora and fauna, and massive, uncontrolled growth on algae and aquatic weeds.

• The impact of polluted water entering our environment are diverse, but in summary: there are human health issues, including cholera and gastro enteritis; and there are environmental impacts, relating to the reduced availability of oxygen in the water for aquatic species as a result of the natural oxidation of the polluted water entering the environment

BOX 1: Methane Characteristics [2]

Molecular formula: CH4 Molar mass: 16.042 g/mol Appearance: Colourless gas Density (gas): 0.717 kg/m3 Density (liquid): 415 kg/m3 Melting point: -182.5 oC, 91 K, -297 oF Boiling Point: -161.6 oC, 112 K, -259 oF Solubility in water: 3.5 mg/100 mL (17 oC) Global warming potential: 21

In dealing with sewage and the organic fraction of MSW (OFMSW), our global society is geared around centralised services provision, meaning that water-borne sewage enters a sewerage system to be treated at a central WWTW, and that all of our solid waste – from homes, offices and industry – is collected and sent to landfill sites. In current thinking this approach can be termed an ‘end-of-pipe’ solution, meaning that the wastes flow through to the system only to be treated at the end. The alternative is to rather deal with these wastes further upstream, and even on-site. A perfect example of this would be on-site composting of OFMSW, and installation of an on-site sewage treatment system. Combing the two waste flows into one stream for treatment is a further, perhaps obvious, opportunity to arrive at the co-treatment of both.

This is of course not to say, to continue the pipe analogy, a mid-stream interception of the wastes. Hence, the OFMSW could be intercepted at existing waste transfer stations for treatment, and existing sewage treatment works could be upgraded. More realistically, in the context of sewage treatment and the ever-increasing demand for new connections to the sewerage system, this work is focussed on on-site and mid-stream interception of wastes and optimising their co-treatment.


3. Planning a biogas energy project Planning a biogas energy project involves a number of steps otherwise referred to as project development. This project development process is the overall set of steps that leads to a fully operational biogas energy system.

3.1 Outline of biogas energy project development There are six overall steps in the project development as indicated in Figure 1. The project concept is outlined at a basic level, so that the ultimate end point is well defined. Thereafter, the project feasibility – which assesses technical, financial and legal factors – is undertaken. This feasibility study can happen at different confidence levels, according to need and budget. If the project appears feasible, the project preparation steps can be undertaken. This leads to implementation, whereafter the biogas energy system is ready for commissioning. Thereafter the project moves into the operation & maintenance stage. For a full cradle to grave (or cradle to cradle) cycle one could include a seventh step that would consider re-investment, renewal and replacement of components and ultimately responsible demolition.

The first three steps – conceptualisation, feasibility and preparation – are described below, while the implementation and commissioning steps are described in Section 3.3, and the operation & maintenance in Section 3.4.

Figure 1: Project development stages

3.1.1 Project conceptualisation In general, biogas projects can be relatively complex since they cover a wide range of aspects and sectors. Of course, in the early stages of a municipality’s development of biogas projects there may be some really opportune projects that are quite simple, for example, an existing industrial waste water flow treated anaerobically where the produced biogas simply needs conversion to useful energy. During the project identification and conceptualisation stage, it is important to consider technical, financial, financing, organisational and legal issues that might be relevant. These considerations could be framed as the following questions:

• What technology will be used? Is this technology locally available?


• If there were no local suppliers, what after-sales support would there be from international suppliers? What influence does the exchange rate have on the viability of the project?

• Is there existing infrastructure that can be used as part of the project?

• Is there a continuous, uniform and secure feedstock supply?

• What form of energy outcome is desirable: heat, electricity, or both? Identifying a possible use for ‘waste’ heat can often be the factor that turns a non-viable project into a viable one

• Can the digestate be utilised? Is there a buyer for the product, and how difficult is it to transport?

• Is it likely that the required permits will be obtained?

• Is the project financially viable?

This last question is perhaps the most important, since without evidence of the project’s viability, no investor will commit to the project. At this stage of the project a simple cost-benefit analysis would be adequate; if the outcome of this assessment is positive, and positive answers to the other questions are obtained, then the project feasibility can be undertaken.

3.1.2 Feasibility study The feasibility study assesses the best options from a feedstock, gas use and financial perspective, while evaluating institutional arrangements, key risks and regulatory requirements. The regulatory requirements may include an EIA, which can be problematic because of the risks of not being able to clearly differentiate the project from other, more general concerns. One means of addressing this issue is making clear the benefit of improved site management that is likely to occur from the project because of the enhanced revenue and management requirements. [3].

Accompanying these guidelines is a financial model and technical report covering the technology of biogas and it applications, municipal waste data for the main South African metros and municipalities, case studies of biogas plants in municipal contexts and discussion of the feasibility model.

The model and technical report is a financial feasibility plan for a biogas digester in a municipal area, giving costs per quantity of waste or per size of digester, quantities of biogas and other plant outputs, amounts and types of waste required, savings that may accrue as a result of reduced infrastructure costs for sewage treatment. The aim is to assist officials compile a feasibility study with figures, benchmarks and thresholds so that municipalities can assess if a biogas digester might feasibly work in their municipal area.

The project depends on a secure and continuous feedstock supply (contract duration, quality/quantity guarantees, payment conditions) as well as energy product and digestate sales assurance. The feasibility needs to consider a financing strategy and involvement (from an early stage) other key factors such as local authorities, feedstock suppliers, financing companies and the general public [4].

The feasibility of the location of a biogas project should take the following into consideration [4]:

• A suitable distance from residential areas in order to avoid inconveniences, nuisance and thereby conflicts related to odours and increased traffic to and from the biogas plant.

• The direction of the dominating winds must be considered in order to avoid wind born odours reaching residential areas.


• The site should have easy access to infrastructure such as to the electricity grid, in order to facilitate the sale of electricity and to the transport roads in order to facilitate transport of feedstock and digestate.

• The soil of the site should be investigated before starting the construction.

• The chosen site should not be located in a potential flood affected area or high water table (generally building in an area of high water table is difficult and expensive and best to avoid).

• The site should be located relatively close to feedstock production aiming to minimise distances, time and costs of feedstock transportation.

• For cost efficiency reasons, the biogas plant should be located as close as possible to potential users of the produced heat. Alternatively, other potential heat users such as heat demanding industry, greenhouses etc. can be brought closer to the biogas plant site.

• The size of the site must be suitable for the activities performed and for the amount of biomass supplied.

3.2 Planning and Preparation The following points present a simplified outline of the main steps for the planning and preparation for implementation of a project.

• Quantitative Survey (understand the actual and projected raw material quantities and types).

• Site Survey (ensure that the correct site is selected relative to the chosen design).

• Soil conditions (geotechnical information should be established to determine the type of ground to determine issues bearing capacity and porosity, as considered in the feasibility).

• Topography and gradient (best options around cut and fill, ground export and import relative to the type and slop of the land)

• Existing structures and services (consider proximity to existing structures and understand cost relating to keeping them intact and unspoilt, understand the extent of existing services and ensure that they are avoided and the cost thereof)

• Proximity to source of waste (ensure that the site and source of raw material are optimally and cost effectively considered)

• Health and Safety (All management parties involved in a project should have a full knowledge of the contents of the OSH Act, task specific method statements and risk assessments should be relayed and signed-off by all involved in the project)

• Labour, Plant and Equipment (consider for implementation phase and running (operation and maintenance) phase)

• Method Statement and Risk Assessment Document (these documents need to be drawn up for a clear understanding of all phases on implementation and O&M to aid in understanding system methodologies, risks and hazards, and to transfer accountability and liability and responsibility accordingly)

• Programme (for control and cost effectiveness any implementation and operation should have a programme to measure against)

3.3 Project implementation Once an approved design has been received the following points should be considered:


• Materials and Materials Quality (it is preferable to use durable tried and tested (SABS) or industry certified materials and equipment - new and innovative products should only be used if they have been tested or successfully piloted)

• Implementation Standards (ensure that there is a standard against which actions can be measured which aid in control and quantifiable conditions)

• Construction (use industry recognized contractors, adopt sound contracting procedures)

3.4 Operation and Maintenance The following points cover some operational and maintenance issues, specifically trouble shooting for a fixed dome reactor:

• Sometimes misinformation or high expectations given to the client translate to the failure of a biogas system and no troubleshooting or repairs will help this. It is important to use a reputable and experienced contractor and design team.

• If all the components of planning, design, implementation and operations & maintenance are adhered to, then troubleshooting will be kept down to a minimum.

• It should be noted that if the plant has been designed and installed correctly one of the biggest problems to overcome with a fixed dome design is scum formation within the reactor. It is therefore important the correct types of un-contaminated feedstock, at the right consistency and in correct volumes, are placed into the system only.

• If there is a reduction in biogas production or biogas quality reduces (both symptoms showing up as loss in energy output), when other factors are constant (feed type and quantity, temperature and other process parameters) then troubleshooting is required.

• If the digested output has an unpleasant smell, then it is not sufficiently processed and troubleshooting is required

• The operator should be given a breakdown of troubleshooting procedures and must keep a record of the problems, and should know whom to contact if additional assistance is required.

• As a rule of thumb, sudden problems with a biogas plant are usually due to blockages and gradually occurring problems are due to leaks or biological malfunctioning.

4. Legal framework The section covers an analysis of national law, provincial law and municipal by-laws that relate to biogas (relative to sewage treatment, energy production, waste management) with details as to how each either supports or hinders the establishment of biogas digesters in municipal areas.

4.1 Overarching legislation Waste in South Africa is currently governed by means of a number of pieces of legislation, including:

• The South African Constitution (Act 108 of 1996)

• Hazardous Substances Act (Act 5 of 1973)

• Health Act (Act 63 of 1977)

• Environment Conservation Act (Act 73 of 1989)


• Occupational Health and Safety Act (Act 85 of 1993)

• National Water Act (Act 36 of 1998)

• The National Environmental Management Act (Act 107 of 1998)

• Municipal Structures Act (Act 117 of 1998)

• Municipal Systems Act (Act 32 of 2000)

• Mineral and Petroleum Resources Development Act (Act 28 of 2002)

• Air Quality Act (Act 39 of 2004)3

• Waste Act (Act 59 of 2008)

Some key pieces of relevant legislation are discussed in more detail below.

4.1.1 Municipal Systems Act Act No 32 of 2000 entitled “Local Government: Municipal Systems Act, 2000” is an important piece of legislation as it relates to the planning and undertaking of municipal service development [5]. Amongst others, the objectives of the Act are to “provide for the core principles, mechanisms and processes that are necessary to enable municipalities to move progressively towards the social and economic upliftment of local communities, and ensure universal access to essential services that are affordable to all; to provide for community participation; to establish a simple and enabling framework for the core processes of planning, performance management, and resource mobilisation; to provide a framework for local public administration and human resource development; and to provide for legal matters pertaining to local government.

Section 77 of the Act indicates those occasions when municipalities must both review and decide on a mechanism to provide municipal services, including when:

• preparing or reviewing its integrated development plan;

• a new municipal service is to be provided;

• an existing municipal service is to be significantly upgraded, extended or improved; or

• instructed to do so by the provincial executive acting in terms of section 139(l)(a) of the Constitution.

In the context of energy from waste, the second item is the most likely reason for needing to decide on an appropriate mechanism. If such a need arises, then Section 78 of the Act sets out the criteria and process for deciding on mechanisms to provide municipal services. When a municipality has to decide on a mechanism to provide a municipal service in the municipality, it must first assess:

• the direct and indirect costs and benefits associated with the project if the service is provided by the municipality through an internal mechanism, including the expected effect on the environment and on human health, well-being and safety;

• the municipality’s capacity and potential future capacity to furnish the skills, expertise and resources necessary for the provision of the service through an internal mechanism4;

• the extent to which the re-organisation of its administration and the development of the human resource capacity within that administration could be utilised to provide a service through an internal mechanism;

3 For copies of this legislation visit www.polity.org.za/pol/acts/

4 Where an internal mechanism includes a department or other administrative unit within its administration; any

business unit devised by the municipality, provided it operates within the municipality’s administration and under the control of the council in accordance with operational and performance criteria determined by the council; or any other component of its administration.


• the likely impact on development, job creation and employment patterns in the municipality; and

• the views of organised labour.

Importantly, the municipality may also take into account any developing trends in the sustainable provision of municipal services generally. Hence, working examples of biogas systems undertaken in this context (of improved and more sustainable waste management) should influence a municipality’s decision to move in this direction.

After having undertaken the above assessment, a municipality may:

• decide on an appropriate internal mechanism to provide the service; or

• before it takes a decision on an appropriate mechanism, explore the possibility of providing the service through an external mechanism5.

If a municipality decides to explore the possibility of providing the service through an external mechanism it must:

• give notice to the local community of its intention to explore the provision of the service through an external mechanism; and

• assess the different service delivery options taking into account

(i) the direct and indirect costs and benefits associated with the project, including the expected benefit of any service delivery mechanism on the environment and on human health, well-being and safety;

(ii) the capacity and potential future capacity of prospective service providers to furnish the skills, expertise and resources necessary for the provision of the service;

(iii) the views of the local community; (iv) the likely impact on development and employment patterns in the

municipality; and (v) the views of organised labour.

4.1.2 Municipal Finance Management Act Act No 56 of 2003 entitled “Local Government: Municipal Finance Management Act” was enacted to “secure sound and sustainable management of the financial affairs of municipalities and other institutions in the local sphere of government; to establish treasury norms and standards for the local sphere of government; and to provide for matters connected therewith” [6].

4.2 Energy

4.2.1 White Paper on Renewable Energy

The White Paper on Renewable Energy (2003) identifies waste as one of energy resources in South Africa [7], and provides the policy framework within which EfW projects can be developed and operated. This policy indicates the potential of generating energy from domestic and industrial waste streams, which in a business-as-usual are disposed of in a manner that they become an environmental burden. The Renewable Energy (RE) policy also highlights that the Municipal refuse disposed of in 1990 had an annual calorific value of 40.5 PJ [7]. The National Energy Bill and the RE policy give a provision of employing suitable technologies in South Africa that could efficiently recover renewable energies [7] [8].

5 Where an external mechanism means entering into a service delivery agreement with (i) a municipal entity; (ii)

another municipality; (iii) an organ of state, including (a) a water committee established in terms of the Water Service Act (1997), (b) a licensed service provider registered or recognised in terms of national legislation, and (c) a traditional authority; (iv) a community based organization or other non-governmental organization legally competent to enter into such an agreement; or (v) any other institution, entity or person legally competent to operate a business activity.


The advantage of applying the EfW concept is that this approach will not compete for waste with the upstream Waste Minimisation strategies (e.g. recycle, reuse, recovery). Instead it utilises residual waste, hence it effectively reduces the waste load going into a landfill. Almost all solid waste generated in South Africa is deposited into landfills. The decaying of this waste in a landfill leads to the release of methane. Methane can be used widely to meet energy needs. Energy policy identifies waste as one of the six key renewable energy resources in South Africa, which has not yet been fully tapped.

4.2.2 Department of Minerals and Energy

The Department of Minerals and Energy (DME) is the State organ responsible for ensuring exploration, development, processing, utilisation and management of minerals and energy resources in South Africa [9]. DME’s mandate is to provide services for the effectual transformation and governance of minerals and energy sectors, for sustainable development thereby improving the quality of life for South Africans [10].

Recently the DME has split into two separate departments of energy (DoE) and of minerals. This allows for better focus on each sector and avoids confusing the needs and priorities of one over the other.

4.2.3 National Electricity Regulator and the new Energy Regulator

The National Electricity Regulator of South Africa (NERSA) is the regulatory authority of the electricity supply in South Africa. The “NER” was established on the 1st April 1995 and more recently became known as NERSA [11]. The NER succeeded the former Electricity Control Board (ECB), which regulated Electricity Supply Industry for more than 70 years in South Africa. NERSA is a statuary body established in terms of the Electricity Act

The primary function of NERSA is to licence electricity generation, transmission and distributions; to approve electricity tariffs and; to set minimum standards for quality supply and service. Furthermore, NERSA play an important role of resolving disputes between electricity suppliers and their customers, as well as between suppliers themselves [12]. The NERSA gets its mandate from Minister of Minerals and Energy and was established through the Energy Regulator Act/Bill of 2004 [13], and acts as an enforcer and monitor of electricity regulation. NERSA’s mandate expanded to include gas and the petroleum pipelines.

The sources of funds that will enable the NERSA to be financially independent will be collected from [13]:

• money appropriated by Parliament,

• levies imposed through separate legislation,

• license fees, and

• money collected under Section 5B of Electricity Act.

4.2.4 Renewable Energy Feed-in Tariff

Guidelines for the Renewable Energy Feed-In Tariffs (REFiT) were published in March 2009 by NERSA. The REFiT is a mechanism to promote the deployment of renewable energy that places an obligation on specific entities to purchase the output from qualifying renewable electricity generators at pre-determined prices.

Feed-in Tariffs (FIT) are, in essence, guaranteed prices for electricity supply rather than conventional consumer tariffs. The basic economic principle underpinning the FITs is the establishment of a tariff (price) that covers the cost of generation plus a "reasonable profit" to induce developers to invest. Under this approach it becomes economically appropriate to award different tariffs for different technologies. The price for the electricity produced should be set at a level and for a period that provides a reasonable return on investment for a specific technology. The tariff should also be certain and long term enough to allow for project financing to be raised by the project.


Feed-in tariffs to promote renewable energy have now been adopted in over 36 countries around the world, including Spain and Germany and a number of states in the US, and also including developing nations such as Turkey, Thailand, Sri Lanka, Nicaragua, Indonesia, Ecuador, China, Brazil, Argentina and most recently Kenya.

The establishment of the Renewable Energy Feed-In Tariff (REFiT) in South Africa will provide an excellent opportunity for South Africa to increase the deployment of renewable energy in the country and contribute towards the sustained growth of the sector in the country, the region and internationally.

To fulfil the Purpose as laid out in Section 2, the specific objectives and key principles of the REFiT are to:

i. create an enabling environment for renewable electricity power generation in South Africa;

ii. establish a guaranteed price for electricity generated from renewables for a fixed period of time that provides a stable income stream and an adequate return on investment;

iii. create a dynamic mechanism that reflects market, economic and political developments;

iv. provide access to the grid and an obligation to purchase power generated;

v. establish an equal playing field with conventional electricity generation; and

vi. create a critical mass of renewable energy investment and support the establishment of a self sustaining market.

Eskom has been named as the designated Renewable Energy Purchasing Agency, or REPA.

A Qualifying Renewable Energy Power Generator shall be defined as new investments in electricity generation using the following technologies:

i. Landfill gas power plant;

ii. Small hydro power plant (less than 10 MW);

iii. Wind power plant;

iv. Concentrating Solar Power plant.

The following tariffs have been determined:

Technology REFiT (R/kWh)

Wind 1.25

Small hydro (< 10 MW) 0.94

Landfill gas 0.90

Concentrated solar 2.10

It is noteworthy that three technologies are not represented: solar photovoltaics, electricity from biomass, and electricity from biogas. However, the REFiT is to be revised in a 6-monthly cycle and hence there is still good opportunity to include at least biogas on to the list of qualifying technologies. In order to do so, the business case needs to be prepared that will assist NERSA in determining the appropriate tariff level. This feasibility modelling will no doubt assist in this process.


4.3 Water A guideline document issued by the Department of Water Affairs & forestry (DWAF) outlines some of the key elements required as it pertains to undertaking new wastewater projects, or upgrading existing facilities [14].

For proposed projects, it is necessary to address only the environmental issues that may be affected by the operational activities themselves. For existing operations the emphasis changes from an assessment of the potential impacts of a project on the virgin environment to establishing the actual impacts of an operation on an environment in which development has already taken place.

Specifically, in terms of the National Water Act (NWA) of 1998:

• In terms of section 22, a water use must be licensed unless it is listed in Schedule I, is an existing lawful use, is permissible under a general authorisation, or if a responsible authority waives the need for a licence.

• In terms of section 27, in issuing a licence a responsible authority must take into account all relevant factors included under sections 27(1)(a – k).

• In terms of the NWA all licences contemplated must incorporate the essential requirements of section 28.

• In terms of section 29(1)(a – i) and 29(2), a responsible authority may attach conditions to a licence.

• In terms of section 30(1 – 6), a responsible authority may, if necessary for the protection of the water resource or property, require the applicant to give security in respect of any obligation or potential obligation arising from a licence to be issued under this Act.

Specifically, in terms of the Water Services Act (WSA) of 1997:

• In terms of Chapter III, section 11(1) of the Water Services Act, 1997 (Act 108 of 1997) every water services authority has a duty to all consumers or potential consumers in its jurisdiction to progressively ensure efficient, affordable, economical and sustainable access to water services.

• In terms of Chapter III, section 12(1) (a and b) every water services authority has the duty to prepare a water services development plan which must contain details as set out in section 13. In terms of section 15(5) the water services development plan must form part of any integrated development plan contemplated in the Local government Transition Act, 1993 (Act No. 209 of 1993) and in terms of section 18(1) must report on the implementation of its development plan during each financial year.

• Sections 19 and 20 indicate the requirements for contracts and joint ventures for water services providers.

• Section 21 (3)(b)(i – v) indicates the requirements for the provision of by-laws.

In order for a proper assessment of these applications to be made, it is essential (and obligatory in terms of the NWA) that the applicant furnish detailed information concerning the operations. Further details can be found in the Aide Memoire [14].

4.4 Solid waste

4.4.1 Integrated Pollution and Waste Management Policy for South Africa

The White Paper on Integrated Pollution and Waste Management for South Africa sets out the government’s stance on pollution and waste [16]. The Policy’s main objective is


pollution prevention thus minimizing the impact on the environment. It encourages cooperative governance between various levels of government, public and private sectors to work towards achieving a cleaner environment.

The White Paper follows on from the over-arching policy presented in the White Paper on Environmental Management for South Africa (1998) [17]. This is further supported by the National Environmental Management Act (No. 107 of 1998) (NEMA) [18]. However, the guiding principles are based upon the Constitution, the Bill of Rights, and NEMA.

South Africa’s previous focus was on managing waste and its associated concerns once it is generated. However, this has now been shifted towards pollution prevention. Additionally, it aims to ensure that any pollution on the environment is remedied by holding the responsible parties accountable while prosecuting those in non-compliance.

The White Paper [17] covers:

• the global and national context of integrated pollution and waste management,

• key issues relating to pollution and waste management identified through stakeholders during the public participation process,

• the reasons for changing the emphasis from control to prevention,

• Approaches to integrated pollution and waste management policy criteria affecting governance,

• the government’s strategic goals and supporting objective for addressing the major issues regarding pollution and waste, and for measuring the success of policy implementation,

• the government’s approach to governance, detailing the powers and responsibilities of the different spheres and agencies of government and the regulatory approach to integrated pollution and waste management,

• ‘the way forward’, and

• the emphasis on reactive control, rather than proactive measures to manage air quality.

4.4.2 National Waste Management Strategy

The National Waste Management Strategy [19] translates into action the Government’s policy on waste as set out in White Paper on Integrated Pollution and Waste Management for South Africa [16]. It presents a plan up to the year 2010. The objective of integrated pollution and waste management policy is to move away from fragmented and uncoordinated waste management to integrated waste management. Such a holistic and integrated management approach extends over the entire waste cycle from cradle to grave, and covers the prevention, generation, collection, transportation, treatment and final disposal of waste.

While the long-term objective of the strategy is waste prevention and minimisation, a number of corrective actions such as improved waste collection and waste treatment are required in the shorter term due to prevailing inadequate waste management practices. The short-term priority Action Plans of the National Waste Management Strategy include:

• Integrated Waste Management Planning Waste Information System,

• General Waste Collection,

• Waste Minimisation and Recycling,

• Waste Treatment and Disposal, and

• Capacity Building, Education, Awareness and Communication.


4.4.3 Waste management legislation for South Africa

The purpose of legislation is to protect and control utilisation of environment by supporting the main objectives of waste management. Some of these objectives include:

• minimisation of waste generation,

• enhancing environmentally sound waste recycling and re-use, and

• promoting environmentally friendly waste treatment and disposal.

The control of environmental pollution in South Africa is regulated by Sections 19 and 20 in Part IV of Environmental Conservation Act (Act No. 73 of 1989) [20]. Section 19 addresses the prohibition and removal of litter from the environment with particular emphasis to areas that have public access. The new Environmental Conservation Amendment Act (Act 50 of 2003) (ECAA) has been developed to amend the Environment Conservation Act, 1989 (Act No. 73 of 1989). The ECAA provides amendments specifically for the following [21]:

• transfer of administrative powers of waste disposal sites from Minister of Water Affairs and Forestry (DWAF) to Minister of Environmental Affairs and Tourism (DEAT),

• powers to DEAT to formulate regulations regarding control of waste types and products which may cause detrimental effect on the environment and human health if they enter waste stream, and

• powers to DEAT regarding financial matters relating to identified waste types (e.g. plastic bags) and deposition systems.

The ECAA particularly informs Part IV of the Environment Conservation Act (ECA), which focuses on “Control of Environmental Pollution”. Section 20 of ECA is titled ‘Waste Management’ and deals with management of waste disposal sites, commonly know as landfill sites. The administration of landfill sites was however undertaken by Minister of Water Affairs and Forestry. This contradicted the integrated approach to pollution control and waste management as set out in the White Paper on Integrated Pollution Control and Waste Management for South Africa [16]. The overall objective of ECAA is to allow for more integrated approach to waste management by locating responsibilities of all aspects of waste hierarchy (e.g. waste recycling, minimisation, disposal, etc) to one Minister, that of Environmental Affairs and Tourism. Environmental Law Subcommittee, respective ministers and MECs have agreed upon this transfer.

Furthermore, the current ECA of 1989 [20] does not give DEAT regulatory powers to control products, materials or substances that may cause harm to the environment when they enter the waste stream. An example of such materials is the asbestos products. Therefore the ECAA amends the ECA to allow Minister and DEAT to make regulations that will prohibit, control and regulate substances that may have detrimental effect on the environment and human health. Moreover, the Environmental Conservation Amendment Bill which preceded ECAA sought to allocate additional regulatory powers to DEAT in order to promote waste recycling and minimisation with regard to some waste types such as glass, plastic, tyres, and so on [22].

The Department of Environmental Affairs and Tourism (DEAT) published the Waste Management Bill for South Africa for comment in 2007, with the objective of the Bill being to propose the Waste Management Act. This Act is further discussed in section 0. The National Environmental Management: Waste Act of 2008

The most recent piece of national legislation relating to solid waste is the National Environmental Management: Waste Act 59 of 2008. This was assented to by the President of the Republic of South Africa on 6 March 2009 and was published in the Government Gazette on 10 March 2009. The Act essentially repeals all waste legislation


in other pieces of legislation into one single piece of legislation. However, no provision has been made in the Bill that regulates the utilisation of waste stream for other purposes such as power generation.

The Act will come into effect on a date still to be determined by the Minister by proclamation in the Government Gazette.

The Waste Act inter alia:

• Creates a general duty on the State to put in place uniform measures that seek to reduce the amount of waste generated and to ensure that, where waste is generated, the waste is re-used, recycled and recovered in an environmentally friendly manner prior to it being treated and disposed of in a safe manner;

• Facilitates the establishment of a national waste management strategy as well as national and provincial norms and standards for the management of waste including those relating to the classification of waste, waste management services and the storage, treatment and disposal of waste (including the planning and operation of waste treatment and waste disposal facilities);

• Provides for various specific waste management measures, including:

o The declaration of priority wastes by the Minister by notice in the Gazette and the waste management measures to be taken in relation to declared priority wastes;

o The creation of various general duties on a “holder” of waste to take reasonable measures, including to avoid the generation of waste, to reduce, re-use, recycle and recover waste, to dispose of waste in an environmentally sound manner, and to manage the waste so that it does not endanger health or the environment;

o Stipulating that, where reduction, re-use, recycling and recovery of waste is undertaken, unless otherwise provided for in the Act it must be ensured that such activities use less natural resources than the disposal of the waste and, to the extent that it is possible, are less harmful to the environment than the disposal of such waste;

o The declaration of certain wastes which will be subject to extended producer responsibility and the specification of certain extended producer responsibility measures that must be taken;

o The declaration of certain listed waste management activities which cannot be commenced with, undertaken or conducted without complying with the requirements or standards to be determined or without a waste management licence if such a licence is required. Pending publication of such list/s, Schedule 1 of the Act is applicable (“Waste management activities in respect of which a waste management licence is required”);

o Setting specific requirements for the storage, collection and transportation of waste;

o Setting specific requirements for the treatment, processing and disposal of waste, including a prohibition against the disposition of waste at an unauthorised disposal facility;

o Requirements regarding the preparation of industry waste management plans by individuals and organs of state;

o Provisions regarding contaminated land, including: o The application of the Act to land that was contaminated prior to the

commencement of the Act; o The identification and notification of investigation areas, such as land

where high-risk activities have taken place or are taking place that are likely to cause contamination, including the consequences attached to such identification and notification, such as the remediation of the land after consideration of the requisite site report, as well as a limitation on the transfer of remediation sites.


• Provides for the licensing and control of waste management activities, including:

o The procedure for application for a licence, including the factors to be taken into account by the licensing authority, as well as the criteria for a fit and proper person which must be taken into account when considering an application;

o Provisions regarding the decision of licensing authorities on applications, the issuing of waste management licences, the contents of the licence, and the transfer of licences; and

o The Act makes provision for the review, variation, renewal, revocation, suspension and surrender of licences.

The Act further makes provision for compliance issues, including penalties and offences, regulations, the consultative process that must be followed by the Minister or the MEC before exercising a power in terms of the Act, and the procedures to be followed for appeals and exemptions.

When it comes into effect, the Act will repeal the relevant provisions of the Environment Conservation Act 73 of 1989 (including section 20 of that Act dealing with waste disposal site permitting), but also provides for transitional provisions in respect of permits issued in terms of the Environment Conservation Act 73 of 1989 and other transitional provisions, including regarding the Schedule 1 listed waste management activities.

4.4.4 Polokwane Declaration on Waste Management in South Africa

There is an ever growing global call on efficient resource utilization and elimination rather than managing waste. Such concern has led to the evolution of the Zero Waste ideology. Overall Zero Waste is a systematic approach to resource management that strives to maximize recycling, minimize waste, reduce consumption and ensures that products are made to be reused, repaired or recycled back into nature or the marketplace [24].

The South African community vis-à-vis the government, business and civil society adopted “The Polokwane Declaration on Waste Management” at the First National Waste Management summit held in Pietersburg, South Africa from the 26th to the 28th of September 2001 [25] - hereafter termed the Polokwane Declaration. The Polokwane Declaration called for consorted effort amongst the parties to reduce waste generation and disposal and also participation in a whole host of initiatives aimed at sustainable resource utilization. The following is an overview of the goals and targets that were agreed upon [26] [27]:

• Reduction of waste generation and disposal by 50% and 25% respectively by 2012;

• Promotion of recycling opportunities, which are sustainable;

• Engagement in activities that will grow the recycling industry by 30% by 2012; and

• Zero waste by 2022.

The Zero Waste concept adapted in the Polokwane Declaration seeks to shift South Africa into a truly sustainable economy through clean technology and production consequently resulting in efficient use of energy and resources. The set goal of Zero Waste by 2022 brings the following challenges and perceptions into focus:

• Reengineering of the current linear input/output industrial model into a circular model promoting the use of end products. The Polokwane Declaration also aims to have clean production processes and resource accountability been adopted in the South African industrial economy.


• Promotion of waste avoidance, prevention, reduction, re-use and recycle. Waste elimination at source as compared to an end-of-pipe waste management style is cited.

• The implementation of the National Waste Management Strategy (NWMS) and setting up of a Waste Management Information System (WMIS) are some of the goals deliberated on in the Polokwane declaration.

• The Polokwane Declaration recognizes the need for co-involvement of all interested parties to achieve the set goal. Thorough role playing is critical for attainment of Zero Waste goals. Civic participation is required and the associated benefits such as job creation and creation of efficient local communities as enumerated.

The Zero Waste framework is based on lessons learnt from nature. Zero Waste is a guiding principle that says that waste is not natural and can be eliminated with the proper product design, supportive policy and advocacy efforts. Nature has developed a cyclical material flow system whereby waste from one organism is a resource for another organism. There is mounting concern to revert from unsustainable resource use that is destroying the globe. The current energy and material production and consumption behaviour have made authorities to want to implement the Zero Waste strategy in a bid to have sustainable societies. Parallels have been drawn calling for waste avoidance, recycling, reuse, product liability and related manufacturing strategies, cleaner production technologies and environmental accountability.

Implementation of Zero Waste resource management systems is perhaps one of the most significant steps to the sustainability of the earth’s atmosphere and ecosystems. The Polokwane Declaration adapted by South Africa calls for Zero waste by 2022. The South African government committed to implementing a NWMS, and has since set this in motion. This is commendably transforming the previous waste approach to waste management in South Africa and “prioritizing waste management”. There is a move from the traditional end-of-pipe waste management approach towards the waste recycling reuse, waste avoidance, cleaner production and a number of Zero Waste ‘principles’.

5. Policy Makers' Guide A recent study by UCT on energy from wastewater [28] for WRC provided some guidance for policy makers to assist with the roll out of energy from waste water. While the focus of this study was on waste water the policy guide could arch over solid waste as well. The following points are taken from the report.

• Anaerobic digestion (AD) for the production of biogas is by far the most prominent technology as a means of energy recovery from waste

• The sale of Certified Emission Reductions (CER) through the Clean Development Mechanism (CDM) can make large scale AD projects possible

• The benefits of biogas generation from waste include:

o On site production of heating and/or cooking for households, on-site electricity and heat for industry

o Reduction of pressure on natural resources (such as wood)

o Production of sludge fertilisers which can be applied to cultivated land

• The scope to integrate “energy from wastewater” goals with effective sanitation (MDG 2015) is large

• Free basic alternative energy policy (FBAE 2007) could be linked to voluntary installation of AD biogas systems


• A standard implementation agency is required to ensure uniform standards of design and construction of AD systems – this should improve access to financing government grants or loans, as well CERs

• There is a desperate need for skills development and capacity building to provide sufficient technological expertise to support the roll out and maintenance of energy from waste projects

• Support for demonstration projects would assist in the development of skills and the acceptance and uptake of appropriate energy from wastewater solutions

• There is a lack of effective data collection and data maintenance for waste, especially waste water

• Cumbersome regulatory issues have lead to the lack of success in implementation of existing processes – e.g. the policy that no income generating secondary industries are allowed on state owned operations

• Municipal Finance Act (MFMA) imposes constraints on public-private partnerships (such as the requirement that every project should go out to tender and is limited to three years unless approved by council

• Previously the national electricity tariff structure has not been conducive to energy recovery, although the announcement of special feed-in tariffs may provide a boost

• Policy is needed to support skills training and develop a national capacity to implement new technologies in energy recovery

6. Case Studies This section reports on existing biogas digester systems, both in South Africa and other nations, which are part of an integrated waste management system of municipal areas. Two studies are in South Africa, two are in Europe (UK and Germany) and one is in Asia (Thailand).

Table 1 below gives a summary of the case studies’ most relevant parameters and significant indicators. More detail of each of the case studies is given in sections 6.1 to 6.3.

Table 1: Summary of Case Studies

Country South Africa Europe Asia

Plant Cato Manor PetroSA Bran Sands Moosdorf Rayong

Type Hydraulic fixed slab digester with aquaculture

Gas engine electricity generators

Advanced anaerobic digestion

Dry fermentation Mech treatment & anaerobic digester

Feed-

stock

Sewage (70 m3), OFMSW & Chicken litter (~3t max)

Refinery process waste

Sewage OFMSW and yard waste (12,700 t/a)

OFMSW (25,550 t/a)

Size Small (280 m3

digester) Large Large (2.1 ha) Medium

(7 chambers - 4,000 m2)

Medium

CAPEX R1.2 million (min 4 y breakeven)

R30 million R429 million R21 million (estimated)

R31 million


Output & Benefits

13 t/a LPGe (min)

Max: 67 t/a LPGe

34 GWh/a elec (3 x 1.4 MWe),

33,000 t/a CO2

37 GWh/a elec (4.7 MWe),

2 MWh heat,

R21 mil ROCs

5 GWh/a elec (710 kW),

7 GWh/a heat,

3,500 t/a water

5 GWh/a elect (625 kWe),

43,513 t/a CO2

Cost per Output

R92k/t/a LPGe (min)

Max: R18k/t/a

R882k/GWh/a, R7mil/MWe (elec plant only)

R11mil/GWh/a, R91mil/MWe



Maintenance Low High High Medium High

6.1 South Africa

6.1.1 Cato Manor

6.1.1.1 Introduction Cato Manor is one of five Area Based Management (ABM) precincts identified by the eThekwini Municipality (Durban) for addressing social, economic and spatial development needs and priorities. In the formulation of an appropriate response to unemployment and the need to improve the socio-economic status of Cato Manor residents, the ABM has developed a multi-culture programme that seeks to involve community members in urban agricultural initiatives. The programme involves a considerable amount of investment in infrastructure and programme development.

The eThekwini Municipality through their Cato Manor ABM Branch is currently developing the old SPCA site (amongst others) to accommodate aquaculture, poultry farming, mushroom farming, organic fruit and vegetable farming initiatives, etc. Through various innovative techniques, the agricultural systems are being developed with a view to achieve maximum benefits from each site.

6.1.1.2 Objectives The objective of the project is to investigate integrated waste management with the benefit of energy production and aquaculture in a municipality. This would help turn a waste disposal and treatment problem into a much needed resource within the municipal border.

6.1.1.3 The project The project involves intercepting the municipal sewer, installation of a low-tech small scale biogas digester as first stage treatment, followed by algae raceways as a second stage treatment, followed by aquaculture ponds as a third stage treatment, with the final discharge water being used for irrigation and food production. This is a combination primary settling tank and anaerobic digester where the solids sink and are retained for hundreds of days and the effluent is retained for between 4 and 5 days. The digester is sized on the feedstock loading to prevent wash-out.


Figure 2: Preparing to lay the foundation slab for the digester

Source [AGAMA Biogas]

The peak flow rate from the surrounding community’s wastewater that enters the digester is 70,000 litres or 70 m3 per day. The digester has a reactor volume of 280 m3 and comprises two reactor chambers. The finished top slab is available for later utilisation for example as a netball court, or similar. The digester is designed to co-digest different substrates, not just the sewage. It is anticipated that the digester will also biodegrade food wastes from the community, chicken manures from the on-site chicken production, water hyacinth from municipal collections and fish manures from the downstream aquaculture ponds, amongst other organic substrates. The biowaste will be mechanically macerated before it is fed into the digester.

The connection between the sewer and the biogas digester has an inlet screen separator, which ensures that no foreign non-biodegradable objects enter the digester. The two digester chambers have sludge removal devices operating under gravity to discharge sludge periodically to a composting pit, for further nutrient addition to the food production areas.

The estimated minimum biogas production is 28 m3/day, derived only from the sewage wastes. The digester has a gas holding capacity of 42 m3. Although the ultimate use of the gas has not yet been decided upon, two scenarios for its use are:

• Cooking

With some small amount of additional substrates (about 500 kg/d) and a twice daily use of the biogas for cooking, up to 84 m3 of biogas (twice the gas holding capacity) would be consumed daily. This has an energy amount equivalent to 36 kg of LP Gas production per day, or approximately R750/day. If the maximum substrate of 3 t/d were loaded the gas output rises to 67t/a.

• Electricity

The digester is capable of biodegrading in the order of 3 tonnes of substrates per day. Were this amount to be fed to the digester daily, the potential daily energy production would lie in the range of 510 kWh to 1,020 kWh, depending on the type and proportion of the feedstocks. This is equivalent of a continuous power capacity of 21 and 42 kW, respectively. An amount of 1,020 kWh would be sufficient to power 60% of the 200 households that are connected to the sewer system supplying the digester.


6.1.1.4 Financial assessment The outputs of the overall system are far greater than just the biogas energy derived from the digester: there are financial values associated with the algae, fish protein, and foodstuffs, and economic value derived from the improved social wellbeing and health were these benefits to be consumed by the local community. Yet, for the purposes of this study, we limit the simple breakeven analysis to only the biogas energy aspect.

For cooking (LPGe) the biogas digester, including inlet screen separator but excluding the post digester treatment, has a turnkey budget of R1.2 million. A simple breakeven on the basis of the minimum R750 energy production per day indicates that the project has a breakeven period of approximately four years (and less than a year for maximum energy production).

6.1.1.5 Finding / Outcomes The minimum energy benefit is 13 tonnes of LPG equivalent per year. At today’s prices the simple breakeven for the minimum energy benefit is about 4 years but with energy pricing increasing is likely to be half of this. The maximum energy benefit results in a breakeven of less than a year.

6.1.1.6 Other benefits This project reduces the sewerage volumes (by 70 m3/day) that would have required treatment by the municipality. At the same time it contributes to the municipality’s climate change mitigation by the utilisation and destruction of the powerful greenhouse gas (methane) that is produced by waste water treatment.

6.1.1.7 Lessons learned and repeatability At the time of writing the construction of the facilities is underway. Commissioning is due to be complete by the end of June 2009.

There were delays to the project due to initial scope and planning issues. A digester of this size needs to be planned, designed, built and operated by specialist professionals. It is important to ensure that the engineering and project management capability from the municipality are suited to the scale of the project.

Figure 3: May 2009 – brick walls with reinforcing progressing

Source [AGAMA Biogas]

6.1.2 Petro SA This case study (PetroSA Biogas to Energy Project, MethCap SPV1 (Pty) Ltd) was compiled by the Renewable Energy and Energy Efficiency Program in Southern Africa (REEEP-SA), and presented here with some rearrangement, additions and editing. Source: [29]


6.1.2.1 Introduction The project is the first Independent Power Producer in South Africa to use the Clean Development Mechanism under the Kyoto Protocol and is a 4.2 MW biogas to electricity plant located in Mossel Bay at the state owned gas-to-liquids refinery PetroSA. The project was developed and financed by MethCap, a company owned by international engineering firm WSP Group and minority shareholders include the Central Energy Fund and a group of broad based Black Economic Empowerment investors. Project debt was provided by the Development Bank of Southern Africa. The project uses 3 gas-fired engines supplied by GE Jenbacher and project revenue comprises of electricity sales and Certified Emission Reduction units. The generation plant, which took 11 months to construct, was formally opened by the Minister of Minerals and Energy Ms Buyelwa Sonjica on 28 September 2008 and has been operating ever since.

The project is located at PetroSA, a state owned corporation that has operated a gas to liquids plant at Duinzicht, outside Mossel Bay on the south coast of South Africa, since 1987. The production process at Duinzicht leads to waste process water that has been dealt with by anaerobic digestion since the inception of the Plant. The anaerobic digestion is continuous and a critical process for the operation of the PetroSA plant. Methane rich biogas is naturally generated by anaerobic digestion process. The scrubbed biogas is burned in the reciprocating engines generating electricity. This results in the national grid generating less coal based electricity therefore reducing CO2 emissions by 33,000 tonnes per annum for the life of the project.

Figure 4: The biogas power building at PetroSA

Source: [30]

6.1.2.2 Objectives The main objective of the project is to generate non-fossil fuelled electricity reducing CO2 emissions in South Africa. A further objective was to create a poverty alleviation mechanism in the Eden municipality and this aim is being achieved by paying an annual 7.5% royalty to a poverty alleviation fund for the development of sustainable social projects. The program is managed by and NGO Ikamva Labantu, which has more than 40 years experience in implementing, projects with similar objectives.

6.1.2.3 The Project The project activity included:

• The building of an engine room on existing, already disturbed land, within the PetroSA plant;

• The installation of gas fired combustion engines;


• Piping the gas from the existing T-piece into the engines. Due to the corrosive nature of the gas, the new gas supply pipes to the engines are stainless steel;

• The design ensures oxygen free gas lines and constant positive pressure in the digester and associated piping;

• Three 1.416 MW General Electric Jenbacher engines have been installed to establish an installed capacity (maximum output) of 4.248 MW. The generation set is complete with intercoolers and water coolers and are housed in a specially built, 198 square meter plant room;

• The engines drive coupled electrical generators that produce electricity at 6,6 kV;

• The existing biogas flare stack remains open and on-line to allow for engine shutdowns and to burn excess gas.

• The cable transporting the electricity from the genset to the grid is approximately 1 km, and mostly runs with existing cables below the surface.

• The GE Jenbacher gensets were chosen based on reliability, performance guarantees and operational efficiency.

Figure 5: 1.416 MW Jenbacher gas gensets at PetroSA

Source: [30]

6.1.2.4 Financial resources and partners The total project cost is R30 million which was funded by a combination of debt and equity. The principal project sponsor and sole developer was MethCap SPV 1 and minority shareholders are Central Energy Fund, Ikamva Labantu and NRG Investments, the latter two of which are broad based empowerment companies.

6.1.2.5 Finding / Outcomes The project produces approximately 34 GWh of electricity per annum, which is sold to the local grid at PetroSA displacing coal-based electricity. The tariff paid to MethCap SPV 1 for the electricity matches exactly that of the imported grid cost and contributes a small share to the plants consumption. With the CER revenue, the project is financially feasible.

6.1.2.6 Other Benefits The project reduces 33,000 tonnes of CO2 annually and was registered by the UNFCCC in September 2006. The project created approximately 100 part time jobs directly during different phases of construction and 2 full time positions for the next fifteen years. In addition, the poverty alleviation project will create jobs for approximately 50 people.


6.1.2.7 Lessons learned and repeatability The project implementation was delayed by 5 months due to petrochemical and site specific requirements, which were not in any way anticipated. There were also administrative delays during the project registration phase at the UNFCCC. The general project development process including obtaining licences, permits, approvals, raising debt, project construction and management are universally applicable and similar to those encountered previously in the EU. Particular factors contributing to the success include deep financial and project finance experience, strong technical knowledge and innovation and a pioneering position in the carbon market particular to non-annex 1 countries.

It would be worth seeking out other plants (like PetroSA) within the cities that are already, as part of their process, producing methane rich biogas that can be fed into gas engine electricity generators. These could be, for example, waste water treatment works, refineries or landfills.

6.2 Europe (UK - AAD & Germany - Dry Fermentation)

6.2.1 UK - Advanced Anaerobic Digestion This case study was compiled from information in an April 2009 Renewable Energy World article [31] and the websites of Cambri [32] and Monsal [33].

6.2.1.1 Introduction Northumbrian Water Ltd (NWL) operates 437 waste water treatment plants in the UK. Currently anaerobic digestion processes are employed for about 10% of the sludge in these plants.

Advanced anaerobic digestion technologies produce a greater biogas yield with a reduction of sludge volumes and reduced odours. The sludge is of a better quality resulting in a safer (pathogen free) bio-solids fertiliser.

There are two types of advanced technology used in UK; namely a Cambri process, which is a “thermal hydrolysis” process and a Monsal process, which is an “enzymic hydrolysis” process. The Cambri process utilises a high temperature (165oC) and a high pressure (6 bar), which disintegrates cell structure/organic materials and dissolves naturally occurring cell polymers, a form of protein, into an easily digestible feed for anaerobic digestion. The Monsal process ramps the temperature from 42oC to 55oC over several days. This provides enhanced pathogen reduction and improves the performance of the digestion process.

6.2.1.2 Objectives The objective of the project is to better manage sludge at the waste water treatment plant and improve energy cost stability.

6.2.1.3 The Project A new plant at Bran Sands in Teesside, UK is 21 ha and utilises the Cambri process for treating sludge from Northumbrian Waste Water Treatment Works to replace an energy intensive thermal drying plant for the sludge waste. The thermal hydrolysis advanced anaerobic digestion process reduces 500,000 tonnes of sludge to 60,000 tonnes.


Figure 6: Bran Sands Waste Water Treatment works

Source: [31]

The methane produced is collected in 11m diameter storage bags that feed four combined heat and power (CHP) engines. The 4.7 MWe will produce 37 GWh/a of electricity and 2 MWth heat recovery used in thermal hydrolysis process. The electricity production reduces the grid energy need by about half and the heat recovery reduces the natural gas used for heating. This helps reduce impact of volatile and unpredictable energy prices.

6.2.1.4 Financial indicators The contract to design, construct and install the project was priced at £33 million (R429 million). The project is eligible for renewable obligation certificates (ROCs) worth £1.6 million (R21 million).

6.2.1.5 Finding / Outcomes Construction commenced in the middle of 2007 and biogas production is scheduled to commence by mid 2009 with the full benefits by year end. The project will produce 37 GWh/a of electricity and 2 MWth of heat.

The recycling of treated bio-solids in the agriculture sector is considered ‘best practicable environmental option’ (BPEO) by both UK and EU. The site is covered by Pollution Prevention and Control Regulations (PPC).

6.2.1.6 Other Benefits The project will improves sludge management in area as a whole and reduce maintenance compared to the existing systems.

Thermal hydrolysis at Bran Sands and lime stabilisation at another plant has reduced group’s emissions by 62,000 t/a.

6.2.1.7 Repeatability NWL plans to roll-out the sludge strategy at another plant in Howdon on Tyneside. This in affect means that the same design can be used on other sites learning from the experience of the first plant at Bran Sands and promoting cost savings.

6.2.2 Germany - Dry Fermentation This case study is taken from information on the BioFerm website [34], a presentation by Williams on BioFerm technology [35] and an AGAMA Energy study [36].

6.2.2.1 Introduction The biomass digester of the dry fermentation process is generally a floor heated concrete chamber that seals the biogas in and air out (see Figure 7). Looking at a dry fermentation digester one may easily be fooled into thinking that it is a garage or barn – except for the hydraulically operated gas sealed door, as well as the biogas and percolate


circulating pipes with their control mechanisms. This is the ‘garage’ type dry fermentation plant as used at the Moosdorf Plant in Bavaria Germany (see Figure 8).

The feedstock is introduced in batches – meaning that it is not a continuous flow but rather supplied in discrete batches of biomass that may not be easily pumped but can be ‘stacked’– like the OFMSW and yard waste feedstock at the Moosdorf Plant. The feedstock is moved into the chamber by means of a front-end loader. The biomass can be between 25% and 50% solid and is sealed into the chamber for between 30 and 60 days during which time the biological fermentation takes place automatically at mesophilic temperatures (around 35oC). After that period the chamber is opened and the digested remains removed, which can be used for composting, and another batch introduced to the chamber.

Figure 7: Typical dry fermentation batch process with percolate

Source: [37]

The production of biogas is affected by the quality and mix of the feedstock but generally the biogas produced would have characteristics set out in Table 2.

These percentages may be typical of all fermentation processes. However, the low H2S is an advantage for an electrical generating engine as less scrubbing may be needed with lower corrosion of components (compared to other fermentation processes).

Table 2: Typical characteristics of dry fermentation biogas

Component Percentage

Methane (CH4) 45 - 70%

Carbon Dioxide (CO2) 25 - 55%

Water Vapour (H2O) 0 - 10%

Nitrogen (N2) 0.01 - 5%

Hydrogen (H2) 0 - 1%

Ammonia (NH4) 0.01 – 2.5%

Hydrogen Sulphide (H2S) 0 – 200ppm


Figure 8: Moosdorf dry fermentation energy recovery plant

Source: [BioFerm Energy, Germany]

6.2.2.2 Objectives The objective of the project is to achieve optimal biogas output from municipal organic waste with minimal labour.

6.2.2.3 The Project The project is owned and operated by BIOMethan and is located in Moosdorf, Waldmünchen, south-eastern Germany. The plant supplies electricity to the City of Waldmünchen and heat to the community of Moosdorf.

The plant has seven dry fermentation chambers with a footprint of one acre (just over 4,000 m2). Feedstock totalling 12,700 tonnes per year of OFMSW and yard waste is loaded into the chambers producing about 2 million m3 of biogas per year. The biogas is scrubbed and feeds a 710 kW generator producing about 5 GWhe/a of electricity and 7 GWhth/a of heat.

Nearly 6,000 t/a of dry digestate is produced which is processed to compost. The plant also recovers about 3,500 t/a of water.

6.2.2.4 Financial indicators No published financial information could be found for this project but an AGAMA Energy study [36] indicated a South African capital cost of about R3 million per chamber (including electrical conversion and heat exchangers). This implies a capital cost of about R21 million for this project if it were to be built in South Africa with South African contractors.

6.2.2.5 Other Benefits The dry fermentation plant has the benefit of carbon neutral energy production whilst a low water consumption. There are lower maintenance costs due to fewer moving parts on the digester side.

6.2.2.6 Repeatability Dry fermentation technologies for processing OFMSW are perhaps more appropriate for developing country situations, since the management of large systems is often less complicated and requires simple mechanical processing by means of trucks or loaders that may already be in use at refuse stations. Increasingly dry fermentation for processing OFMSW is establishing itself, especially in Germany, and therefore can be considered to be a plausible and recently proven option for biomass treatment with energy recovery.


6.3 Asia (Thailand) - Rayong This case study is based on a presentation by Based on a presentation delivered by Mr R Price of ICLEI at the Cities Sustainable Energy Strategy conference held in Cape Town, South Africa in 2003. See also [38] and [39].

6.3.1.1 Introduction The area of Rayong Municipality is about 17 m2 with a population of nearly 58,000 housed in about 23,000 households. The climate is hot with high humidity.

Rayong Municipality generates approximately 75 to 85 tonnes of MSW per day, of which 50% is organic waste. The Rayong waste management model comprises of separation at source (recyclables, organic and non-recyclable) with different collection days by the municipality and recycling drop-off points.

Organic waste is collected from community, markets, restaurants, department stores, hotel & night soil. At present, 15 tons/day biowaste is collected from 3,400 households (15% of all households).

6.3.1.2 Objectives The objectives of the project were to promote community participation in organic waste sorting at source and promoting environmental conservation.

6.3.1.3 The project The Rayong facility currently treats 70 tonnes of MSW per day using anaerobic digestion as a core process to produce fertilizer and to generate electricity from biogas. The process is shown in the figure below.

1 Bag opener 6 Feed preparation tank 11 Mechanical dryer

2 Drum screen 7 Bioreactor 12 Process water tank

3 Magnetic separator 8 Biogas holder 13 Thermal dryer

4 Fragmentiser 9 Gas engine generator 14 Fertiliser

5 Suspension tank 10 Buffer storage tank

Figure 9: Schematic of Rayong Municipality OFMSW Treatment System

Items 1 through 6 comprise the Mechanical pre-treatment of the biogas plant, in order to ensure that only organic waste arrives at the digester.

The biowaste has the following composition:

DS (dry solid) content 24.4 %

VS (volatile solid) content of DS 70.0 %

The DS content of this feed is adjusted down to 15% in the feed preparation tank using process water and/or soil liquid.


Figure 10: Process flow diagram for Rayong Municipality OFMSW Treatment System

6.3.1.4 Financial resources and partners The cost of project was US$3.6 million (R31 million) which was granted by the National Energy Policy Office (NEPO). Assuming a CPIX of 8% per annum, the project would cost approximately R57 million today.

6.3.1.5 Finding / Outcomes The project is an integrated waste management process including waste sorting, recycling, composting and capturing Methane to generate electricity. It was managed by local government with local financing which resulted in. cost saving for waste collection (alternated day collecting instead of daily collecting) and income generation from electricity sales. The landfill life was extended due to reduction of input load.

The integrated waste treatment process resulted in the following outputs:

Output from Mechanical Treatment:

Recyclables 6 t/d

Unusable material rejected to landfill 4 t/d

Output from the AD process:

Dehydrated (dried) humus 16 t/d

Biogas (65% methane content) 6,000 m³/d

Electricity 14 MWh/d

625 kWelec

(20% is used for internal consumption, and the surplus electricity is sold to the utility company)


Figure 11: Jenbacher gas gensets at Rayong

Source: [38]

6.3.1.6 Other Benefits Before the implementation of this cogeneration project the emissions from the MSW were 4,540 t/a of methane (95,340 t/a of CO2). After implementation the GHGs emissions from flaring excess methane, gas exhaustion of gas engine were reduced by 43,513 tonnes.

The project promoted social participation in recycling and organic waste sorting, renewable energy and environmental conservation.

6.3.1.7 Lessons learned and repeatability The technology was appropriate for a tropical country where the ambient temperature (35 - 40°C) is appropriate for anaerobic digestion by microorganisms.

People’s participation helped raise awareness of environmental management


7. References [1] http://www.capetown.gov.za/en/solidwaste/Pages/CitysWasteMinimisationsummit.aspx

[2] http://en.wikipedia.org/wiki/Methane

[3] Methane Emission Reduction Opportunities in Twelve South African Cities: Turning a Liability into a Resource, Palmer Development Group for USAID/SACN, 2004

[4] Biogas Handbook, BiG East, October 2008

[5] Act No 32, 2000: Local Government: Municipal Systems Act

[6] Act No 56, 2003: Local Government: Municipal Finance Management Act

[7] Department of Minerals and Energy (DME) (2003): White Paper on Renewable Energy, Republic of South Africa, November 2003.

[8] Republic of South Africa (2004): Draft National Energy Bill, Version 3, 15 September 2004, Minister of Minerals and Energy

[9] Department of Minerals and Energy (DME) (2005), website: http://www.dme.gov.za/

[10] Department of Minerals and Energy (DME) (2005), website: http://www.dme.gov.za/home.asp?menu=about/mission_and_vision.htm

[11] National Electricity Regulator (NER) (2005): NER News, Newsletter on developments in the Electricity Supply Industry, Monthly Issue, May 2005.

[12] South Africa (2005): website: www.info.gov.za/otherdocs/1995/energy.htm

[13] Republic of South Africa (2004): Energy Regulator Bill, Bill published in Government Gazette No. 25994 of 6 February 2004, Minister of Minerals and Energy, ISBN 0 621 34842 2.

[14] Aide Memoire: For the preparation of a Water Quality Management Report to support the application for licences for sewage treatment works in terms of the requirements of the National Water Act 1998 (Act 36 of 1998). Water Quality Management Series, Operational Guideline No U2.1. First Edition, February 2003. Department of Water Affairs and Forestry.

[15] Act no 59, 2008: National Environmental Management: Waste Act, 2008

[16] Department of Environmental Affairs and Tourism (DEAT) (2000): White Paper on Integrated Pollution Control and Waste Management for South Africa; A policy on Pollution Prevention, Waste Minimisation, Impact Management and Remediation; Government Gazette No. 20978, Vol. 417, Pretoria, 17 March 2000.

[17] Department of Environmental Affairs and Tourism (DEAT) (1998): White Paper on Environmental Management Policy for South Africa, Government Gazette No. 18894, Vol. 395, Pretoria, 15 May 1998.

[18] Republic of South Africa (1998). National Environmental Management Act (No. 107 of 1998), Vol. 401, No. 19519, Cape Town, 27 November 1998.

[19] National Waste Management Strategy, National Waste Management Strategies and Action Plans in South Africa, Strategy Formula Phase, Version D, 15 October 1999, www.environment.gov.za.

[20] Republic of South Africa (1989). Environmental Conservation Act (Act No. 73 of 1989). Section 20: Waste Management. Government Gazette, Republic of South Africa.

[21] Republic of South Africa (2003). Environment Conservation Amendment Act (Act No. 50, 2003), Assented to 10 February 2004. Government Gazette No. 26023, 18 February 2004.

[22] Republic of South Africa (2003). Environment Conservation Amendment Bill, Government Gazette No. 252889 of 1st August 2003, B45 – 2003, ISBN 0621338648.

[23] Department of Minerals and Energy (DME) (2003): White Paper on Renewable Energy, Republic of South Africa, November 2003.

[24] Zero Waste, Recycling and Climate Change http://www.grrn.org/general/support.html,

[25] Department of Environmental Affairs and Tourism (DEAT) (2001): Polokwane Declaration. www.environment.gov.za.

[26] http://www.environment.gov.za/SearchAsps/Documents_contents.asp

[27] Global Alliance for Incinerator Alternatives http://www.no-burn.org/campaigns/wssd.html

[28] S. Burton, B. Cohen, S. Harrison, S. Pather-Elias, W. Stafford, R. van Hille and H. von Blottnitz, Energy from Waste Water – a Feasibility Study, Guides..., WRC Project k5/1732, Dept of Chem Eng, UCT

[29] http://www.reeep-sa.org/casestudies

[30] http://www.biothermenergy.com/

[31] Renewable Energy World, April 2009, Advanced Anaerobic Digestion – More Gas from Sewage Sludge


[32] http://www.cambi.no/wip4/detail.epl?cat=10636

[33] http://www.monsal.com

[34] http://www.bioferm-es.com/us/technology/dry-fermentation/

[35] Organic material management: anaerobic digestion via BIOFerm dry fermentation, Oshkosh, WI, January 16, 2009

[36] Biofuels in the City of Cape Town, Energy from Waste, Nov 2007, AGAMA Energy for UNDP/CCT/SI

[37] Evaluation of the newest biogas plants in Germany with respect to renewable energy production, greenhouse gas reduction and nutrient management P. Weiland, Ch. Rieger, Th. Ehrmann Institute of Technology and Biosystems Engineering, Federal Agricultural Research Centre (FAL), Future of Biogas in Europe II, Esbjerg 2-4 October 2003

[38] http://www.scribd.com/doc/7802162/Rayongbiomethanation

[39] https://www.iclei.org/fileadmin/user_upload/documents/SEA/CCP_Projects/Rayong.pdf

8. Resources • Sustainability Guide for Energy from Waste (EfW) Projects and Proposals. Waste

Management Association of Australia – Energy from Waste Division. January 2005.

• The Potential for Renewable Gas in the UK, A paper by National Grid, January 2009

• www.sawic.org.za South African Waste Information Centre

• www.polity.org.za Creamer Media News

• www.susana.org Sustainable Sanitation Alliance

• www.big-east.eu Handbook: Promoting Biogas in Eastern Europe

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