Post on 16-Feb-2022
transcript
QUARTERLY PROGRESS REPORT III
May 29th, 2015 – August 28th, 2015
Assessment and Evaluation of Advanced Solid Waste Management Technologies for Improved
Recycling Rates
PRINCIPLE INVESTIGATOR: Nurcin Celik, Ph.D.
Department of Industrial Engineering
University of Miami
Coral Gables, FL, USA
Telephone: (305) 284-2391
E-mail: celik@miami.edu
TEAM MEMBERS: Duygu Yasar, Mehrad Bastani, and Gregory Collins
WORK ACCOMPLISHED DURING THIS REPORTING PERIOD
In the third phase of this study, the work has majorly focused on collecting technology data for
static pile composting, in-vessel composting, windrow composting, and anaerobic digestion
technologies, and conducting analytical hierarchical process (AHP) for biological treatment
technologies. Recommendations were given for each group of county based on the obtained results
from AHP.
Criteria are redefined for the evaluation of advanced biological treatment technologies.
Criteria are weighed using Expert Choice Decision Support Software for 8 groups.
AHP is performed for 8 groups and the most optimum advanced biological SWM
technology among static pile composting, in-vessel composting, windrow composting, and
anaerobic digestion are selected for each group of county.
Preliminary recommendations are provided based on the obtained results.
Technologies that were not taken into consideration are listed and the reasons are
explained.
Second TAG meeting was held during this period.
The assessment of advanced thermal and biological SWM technologies is completed 100% during
this report period. The collection of data for this study is 100% completed during this report period.
At later phases of this study, recommendations will be studied based on the comments obtained in
the second TAG meeting and the AHP results.
INFORMATION DISSEMINATION ACTIVITIES
The majority of the work conducted in this reporting period has been disseminated via the
following publications and activities.
Journal Paper(s):
D. Yasar, N. Celik and J. Sharit. 2015. Evaluation of Advanced Thermal Technologies for
Development of Sustainable Waste Management Systems in Florida, Journal of
Performability, accepted with minor revision.
Book Chapter(s):
D. Yasar and N. Celik, Assessment of Advanced Biological Treatment Technologies for
Sustainability, In Applying Nanotechnology for Environmental Sustainability, submitted.
Newsletter:
D. Yasar and N. Celik, Assessment of Advanced Thermal Solid Waste Management
Technologies, featured in Talking Trash: Newsletter of the SWANA Florida Sunshine Chapter,
Summer 2015.
Site Visits and Presentations:
TAG II Meeting: Our second TAG meeting took place on August 18th, 2015 in the McArthur
Engineering Building of the University of Miami. We also had set up a conference call for
those who wanted to attend the meeting remotely.
Several comments were given during our second TAG meeting. Attendees suggested our team to
consider conventional waste treatment methods and benchmark the current conventional waste
management method of the county with the advanced technologies while giving recommendations
to groups of counties. Discussions have also evolved around the considerations of the combustion
facilities. For instance, if a county has recently invested in starting a combustion facility, it may
not be very practical, or even feasible for them to invest on an advanced technology. It may prove
more beneficial to considered the advanced technologies for the counties which have a landfill that
is reaching to its designed capacity and do not have a plan to manage their future waste. In the
third phase of the study, such conventional waste management methods will be taken into
consideration when detailing county-specific recommendations.
Attendees also suggested our team to obtain information about a steam pyrolysis facility operated
by the University of Florida. Our team will be contacting the facility and request information about
the financial and operational characteristics of the technology for the next phase of the study.
It was also suggested by attendees to double-check the tipping fees of technologies since they
seemed lower than what they should be. Team will also pay attention to the facts whether or not
the providing data sources consider both the capital and operational costs within these fees. This
may further affect the recommendations when conventional methods are taken into consideration.
Our team will double-check this data from publicly available sources and mainly from the vendors
in the U.S. before further detailing its recommendations.
Attendees suggested that the counties that are close to each other should be grouped together while
giving the recommendations. It is more feasible to jointly establish a facility for the counties close
to each other as they can transfer the waste to a single location easier than those farther away.
While studying the recommendations in our next phase, geographic location of the counties and
their distances to each other will be taken into consideration.
Attendees also expressed that the thermal technologies can be considered as a single option since
the only main difference between them is the process temperature. Our results obtained from the
AHP model suggested the same thermal treatment technology for all groups of counties. The
results also showed that their differences have minimal impact on the results for counties.
Website: The team has updated the website describing this project. The website is accessible
at http://coe.miami.edu/simlab/swm_2015.html.
1. INTRODUCTION
Over the past several decades, both the volume and diversity of Municipal Solid Waste (MSW)
generation has increased markedly worldwide, with the United States exhibiting the greatest rate
of growth, both overall and per-capita, by a significant margin. In 2006, the total amount of
municipal solid waste (MSW) generated globally reached 2.02 billion tons, representing a 7%
annual increase since 2003 [1]. It is further demonstrated that after 2010 global generation of
municipal waste has exhibited approximately a 9% increase per year. This burgeoning growth,
combined with the concomitant increase in the regulation of disposal operations and dwindling
availability of suitable disposal sites, has made the planning and operation of integrated Solid
Waste Management (SWM) systems progressively more challenging. According to the concept of
sustainable waste disposal, a successful treatment of MSW should be safe, effective, and
environmentally friendly [2]. However, existing waste-disposal methods cannot achieve this goal.
As a result of these factors, and growing pressures for environmental protection and sustainability,
the State of Florida has established an ambitious 75% recycling goal, to be achieved by the year
2020. At present, the recycling rate in the State of Florida is approximately 30%, based on a goal
set by the landmark Solid Waste Management Act of 1988. However, Municipal solid waste
(MSW) landfills represent the dominant option for waste disposal in many parts of the world.
Based on 2013 municipal solid waste management data, combustion and landfilling has constituted
the 62% of Florida waste management method [3]. Conventional waste landfills occupy large
amounts of land and lead to serious environment problems [4]. While the use of landfills is
decreasing in many parts of the State of Florida, there are nonetheless thousands of closed landfills
and thousands more that are operating but will close over the next 10–30 years. Furthermore,
landfill facilities lead to significant operational and post-operational care period and costs (Figure
1).
Figure 1: Management phases of a MSW landfill throughout life-cycle
On the other side, incineration technology was developed to reduce the total volume of waste and
make use of the chemical energy of MSW for energy generation. However, the emissions of
pollutant species such as 𝑁𝑂𝑥, 𝑆𝑂𝑥, HCl, harmful organic compounds [5,6], and heavy metals [7,8]
are high in the incineration process. Another problem with MSW incineration is the serious
corrosion of the incineration system by alkali metals in solid residues and fly ash [7]. Furthermore,
due to the low incineration temperature related to the low energy density of MSW, the energy
efficiency of MSW incineration is relatively low [9,10]. Due to aforementioned problem of
conventional technologies, many stakeholders, such as utilities, regulators, governmental agencies,
municipalities, and private firms, have recognized the necessity of establishing advanced solid
waste technologies and integrated solid waste management programs.
Developing these technologies is essential for the State of Florida for several reasons. These
technologies have the potential to enable the State to reduce its waste, and increase its recycling
rate such that its goal of reaching 75% recycling rate by 2020 can be achieved, not by particular
counties that have strong solid waste management structure in place, but by the majority of the
State of Florida counties, including the ones currently struggling with their waste operations. The
new and emerging solid waste management technologies also show potential to create new jobs,
produce renewable energy, and promote economic growth. In addition, while higher recycling
rates may enable lower disposal rates in the landfills, which reduces the land sources utilization
and leaves more room for humans and wildlife, improper implementation of these new
technologies may cause serious problems such as infectious diseases, waste contamination, toxic
emissions, and occupational health issues for solid waste workers. Moreover, current
implementation of these technologies is limited by aspects such as regional divergence, political
factors, market forces, technical supports, amongst many others. Thus, a comprehensive top-to-
bottom assessment of each of these significant technologies as well as their comparison against
each other becomes crucial before their applications are discussed for or appear in the counties of
the State of Florida. However, in light of the inherently challenging nature of the MSW stream and
management, combined with the fiscal difficulties befalling municipalities throughout the state,
numerous technical and social challenges to all parties of solid waste management are presented.
Because these technologies are emerging or being researched in different geographical locations
(other states or maybe other countries), a unified and consistent evaluation scheme has to be
developed before these technologies are considered to be implemented (in part or fully) in the State
Land
fill
Co
nst
ruct
ion
Was
te
Dis
po
sal
Po
st-d
isp
osa
l
Fin
al C
app
ing
Aft
erca
re
(Po
st-c
losu
re
care
)
Surv
eil
lance
No
Car
e
Operational Period Post-operational care period
of Florida counties. To this end, the purpose of this study is to identify and evaluate new and
emerging advanced solid waste management technologies and their potential to help state reach its
recycling goal by 2020 in a manner that is structurally unified, and useful for practitioners in terms
of various criteria such as cost, impact on the waste generation and recycling rates, impact on the
landfill emissions, and byproducts, and impact on the promotion of sustainable economic
development.
2. BACKGROUND AND LITERATURE REVIEW OF ADVANCED SOLID WASTE
MANAGEMENT TECHNOLOGIES
Solid waste generation is a result of every activities and the importance and social and economic
complexity of problems related to solid waste management in industrialized countries have
increased during the last three decades ([11]-[13]). The ideal of completely eliminating waste is
highly unrealistic; therefore, the best approach is to handle solid waste in sustainable way to protect
the environment and conserve the natural resources. Accordingly, significant modifications to
existing waste management technologies and programs have become necessary in order to achieve
the 75% recycling goal established by the state government and obtain most optimal handling of
municipal solid waste for all stakeholders, including environmental managers, regulators, policy
makers, and the affected communities in the state. As a general definition, integrated solid waste
management (SWM) systems are systems that provide for the collection, transfer, and disposal or
recycling of waste materials from a given region. These systems handle a wide variety of materials
collected from the generation units and require numerous specialized facilities and technologies to
process, recycle and disposal these collected materials. Therefore, researchers have conducted a
series of studies on the technologies required for the integrated SWM systems throughout the
MSW life-cycle.
For any solid waste management treatment method, the primary implementation goal is to ensure
that the public health is protected while cost effectiveness is maintained. Compared to traditional
disposal landfills which provide an open loop of MSW life cycle, the advanced disposal
technologies usually combine the recycling and recovery methods, leading to a closed loop of
MSW life cycle (see Figure 2) and thereby improving the recycling rate.
Figure 2: Traditional open loop (left) and advanced disposal landfills close loop cycles (right)
Manufacture
Transfer Station
Customers (Residents)
Collection Fleets Landfill
(End of Line)
Manufacture
Transfer Station
Customers (Residents)
Collection Fleets Advanced Disposal Landfill
Recycling Reuse Recovery
Several researchers have performed evaluation of advanced technologies and analysis for MSW
processing and disposal, in order to decrease landfill utilization and increase the waste recycling
and recovery [13, 14]. Advanced SWM technologies can be categorized in three major groups
including thermal, biological/chemical, and physical technologies. These technologies are known
to be environmentally sound, cost-effective and implementation acceptable ([8]-[10]).
Aforementioned technologies are categorized in Figure 3 to show the technologies in each group.
A similar study has been conducted in New York by New York City Economic Development
Corporation and Department of Sanitation (2004) to provide information for future plan of solid
waste management system. The evaluation considered 43 technologies in total and is conducted
based on a series of criteria, such as readiness and reliability, size and flexibility, beneficial use of
waste, marketability, public acceptability, cost, etc. According to evaluation of advanced SWM
technologies, City of Los Angeles evaluated various technologies and demonstrated that
technologies best suited for processing black bin post-source separated MSW on a commercial
level are the thermal technologies [17]. Chirico [18] has conducted a study with the purpose of
evaluation, analyzing, and comparing SWM technologies and their potential to decrease landfill
utilization and emissions, promote sustainable economic development, and generate renewable
energy in Georgia. In this quarterly report, initially a brief description of advanced SWM
technologies will be provided. Data collection stages will be presented in Section 3. It is followed
by the description of methodology in Section 4. Section 5 will elaborate the AHP methodology.
Finally, recommendations are presented in Section 6.
Figure 3: Categorization of Advanced Solid Waste Management Technologies
2.1 Thermal Treatment Technologies
Data for this category will be provided in data collection section since these technologies are
evaluated using AHP in this quarterly period.
2.2 Biochemical Treatment Technologies
Biochemical (Biological) technologies operate at lower reaction rates and lower temperatures.
Biochemical technologies work material that is biodegradable. Some technologies involve the
synthesis of products using chemical processing carried out in multiple stages. Byproducts can
vary, which include: electricity, compost and chemicals. The most important advanced solid waste
management technologies are defined as follows:
MSW Technologies
Biomechanical Treatment
Thermal Treatment
Anaerobic Process
Anaerobic Digestion
Gasification
Pyrolysis
Plasma
Steam
Waste Convertor
Catalytic Cracking
Advanced Thermal
Hydrothermal
Hydrolysis
De-polymerization
Physical Technologies
2.2.1 Anaerobic Digestion
Anaerobic digestion (AD) is a method engineered to decompose
organic matter by a variety of anaerobic microorganisms under
oxygen-free conditions. The end product of AD includes biogas
(60–70% methane) and an organic residue rich in nitrogen. This
technology has been successfully implemented in the treatment
of agricultural wastes, food wastes, and wastewater sludge due
to its capability of reducing chemical oxygen demand (COD) and
biological oxygen demand (BOD) from waste streams and
producing renewable energy [18]. Harvest’s Energy Garden in
Central Florida uses low solids anaerobic digestion to turn bio
solids and food waste into clean energy and natural fertilizers (Figure 4).
2.2.2 Depolymerization
A significant, valuable percentage of today's municipal solid waste stream consists of polymeric
materials, for which almost no economic recycling technology currently exists. This polymeric
waste is incinerated, landfilled or recycled via downgraded usage. Thermal plasma treatment is a
potentially viable means of recycling these materials by converting them back into monomers or
into other useful compounds [19].
2.3 Physical Technologies
Physical technologies are used to alter the physical characteristics of the MSW feedstock. These
materials in MSW may be shredded, sorted, and/or dried in a processing facility. The output
material is referred to as refuse-derived fuel (RDF). It may be converted into high dense
homogeneous fuel pellets and transported and combusted as a supplementary fuel in utility boilers.
3. DATA COLLECTION for ATSWM Technologies
3.1 Advanced Thermal SWM Technologies
The most important reason for the growing popularity of thermal processes for the treatment of
MSW has been the increasing environmental, technical and public dissatisfaction with the
performance of conventional incineration processes. Thermal technologies operate in high
temperatures which usually ranges from 700oF to 10,000oF. They typically process carbon-based
waste such as paper, petroleum-based wastes like plastics, and organic materials such as food
scraps. The main output (byproduct) of thermal technologies is syngas which can be converted
into electricity. In this section, obtained data for thermal technologies will be presented.
3.1.1 Gasification
The technology data for gasification are obtained from Montgomery Project Gasification Facility
and publicly available online sources. Gasification technology mainly involves the reaction of
Figure 4: Harvest’s Energy
Garden in Central Florida
carbonaceous feedstock with an oxygen-containing reagent, usually oxygen, air, steam or carbon
dioxide, generally at temperatures above 1400oF. It contains the partial oxidation of a substance
which indicates that the amount of oxygen is not sufficient for entire oxidization of fuel. The
process is largely exothermic but some heat may be required to initialize and sustain the
gasification process. Gasification has several advantages over traditional combustion processes for
MSW treatment. Low oxygen environment where the process takes places bounds the formation
of dioxins. Hydrocarbon pollutants are either not formed or removed in the gas clean-up process.
Additionally, it requires just a fraction of the stoichiometric amount of oxygen necessary for
combustion. As a result, it requires less expensive gas cleaning equipment. In terms of efficiency,
it is stated that 90% of incoming energy is available for end use. Finally, gasification generates a
fuel gas that can be integrated with reciprocating engines, combined cycle turbines, and
potentially, with fuel cells that convert fuel energy to electricity more efficiently than conventional
steam boilers. Commercial gasification plants that use MSW as inputs exist in various countries
including Japan, Europe, and North America.
3.1.2 Plasma Arc Gasification
Plasma gasification is a multi-stage process which starts with inputs ranging from waste to coal to
plant matter, and can include hazardous wastes. Feedstock is not combusted since the environment
inside the vessel is deprived of oxygen. Rather feedstock is broken down into elements such as
hydrogen, carbon monoxide, and water. The initial step in plasma arc gasification is to process the
feedstock to make it uniform and dry, and have the usable recyclables sorted out. The second step
is gasification, where extreme heat from the plasma torches is applied inside a sealed, air-
controlled reactor. During gasification, carbon-based materials break down into gases and the
inorganic materials melt into liquid slag which is poured off and cooled. The heat destroys the
poisons and hazards completely. The gas that is created is called synthesis gas or “syngas”. The
syngas created in the gasifier undergoes a clean-up process to make it suitable for conversion into
other forms of energy including electricity, heat, and liquid fuels since it contains dust
(particulates) and other undesirable elements like mercury. The third stage is gas clean-up and heat
recovery, where the gases are scrubbed of impurities to form clean fuel, and heat exchangers
recycle the heat back into the system as steam. In the final stage, the output ranges from electricity
to a variety of fuels, hydrogen, and polymers. The entire conversion process is a closed system so
no emissions are released. According to the Westinghouse Plasma Corporation Report, only about
2-4% of the material introduced into a WPC plasma gasification plant needs to be sent to landfill.
This technology was going to be implemented in St. Lucie County for the first time in the U.S. in
2007, however the project was cancelled in 2012.
3.1.3 Pyrolysis
Pyrolysis systems thermally break down solid waste in the absence of air or oxygen at temperatures
of approximately 600C and 800C. It has the advantage of being relatively simple and adaptable
to a wide variety of feedstock and it can produce several usable products from typical waste
streams. However, solid fuel must be shredded and the moisture content inside solid waste must
be reduced to below 10%. This is one of the reasons that pyrolysis plants have not been successful
in large scale. Pyrolysis produces gases and a solid char product such as activated carbon,
international grade diesel, and synthetic gas as byproduct. Pyrolysis can convert a wide variety of
waste including hazardous waste since it can generate excess heat to reduce moisture content of
waste below 10%. However, it is impractical for large amount of waste. Although pyrolysis of
biomass keeps developing on a relatively small scale, no commercial plants for the pyrolysis of
MSW are operating in the United States today.
3.2 Data Collection Stages
In this quarterly period, advanced thermal SWM technologies are evaluated for different counties
in Florida. The collection of reliable data from various sources comprises a major task in this work,
since these technologies are not currently in widespread commercial use. Data collection is
composed of four stages. In the first stage, the criteria set are defined for AHP. In the second stage
of data collection, SMEs from Floridian counties are contacted to compute the criteria weights. In
the third stage, Florida Department of Environmental Protection solid waste management 2013
annual reports are explored to obtain the annual waste generation for each waste disposal type of
Floridian counties. This data are used to categorize the counties. In the last stage of data collection,
advanced thermal SWM technology data are collected from publicly available sources and defined
facilities.
3.2.1 Defining Criteria Set
The criterion set was defined after inspection of a wide range of journal and white papers in the
first phase of data collection. Several issues such as environmental policies, regulations, public
health and characteristics of advanced thermal SWM technologies were also taken into
consideration. The criterion set and the explanations are given below:
Revenue is the profit that the facility earns by selling the outputs of the process. There are
three potential sources of revenue from a MSW conversion facility which are energy sales,
sales of other outputs, and tipping fees. Revenue from the sale of energy highly depends
on the price for electricity and the net amount of electricity generated. Selling the energy
and products should provide a satisfactory profit.
Tipping fee is a charge for a given quantity of waste received at a waste processing facility.
For financial feasibility of project, tipping fees should be cost competitive and should
provide a significant contribution to the revenue of the facility. Tipping fees typically
constitute the largest source of revenue for a waste disposal facility.
Capital cost of the project is the amount of money which is invested in SWM project.
Operation cost is the ongoing expenses for maintenance of facility.
Development period should not be too long, since competitors could jump into the market
since the solid waste industry is very competitive even in the public sector.
Flexibility of process should be considered since the municipal solid waste has a highly
variable nature. The process should be flexible enough to keep up with the changes of the
content of the waste. Flexibility of process may affect operation costs and tipping fees. The
ability of converting different waste types through a single process lowers the costs as well
as fees.
Land requirements of the facility might be an important issue for some counties that do not
own a readily available land to establish the facility.
Net conversion efficiency shows how much of the received waste is diverted into
energy/marketable products. Net conversion efficiency directly affects the tipping fee since
less efficient processes lead to higher operating costs which are generally paid by higher
tipping fees.
Ease of permitting is the criterion to measure how capable the process is at obtaining the
necessary local and state permits.
Marketability of recovered products shows how much demand exists in the current market
for the outputs of the process. It is not possible to generate the necessary revenue to support
the process if the markets for the outputs being produced don’t have market demand or
current markets are too distance or unstable.
Environmental impact of the process indicates the level of damage that the process or its
byproducts have on the environment. The process itself should not contradict one of its
main purposes which is to reduce the damage on the environment.
Public acceptability measures the level of public support to alternative technology. It is not
possible for a solid waste management facility to function properly without public support.
Number of facilities affects the availability of data and the size of vendors for ATSWM
technologies.
AHP structure for explored ATSWM technologies and defined criterion set is built and given
in Figure 5. AHP structure is designed in a way that environmental, social, economic, technical,
and regulatory issues can be adequately considered. In the second stage of data collection,
criteria weights are determined after contacting SWM of Floridian counties and Florida
Department of Environmental Protection through email communication.
3.2.2 Contacting SMEs
In the second stage of data collection, criteria weights are determined after contacting SMEs from
SWM divisions of Floridian counties and Florida Department of Environmental Protection via
surveys. In order to obtain data for AHP, 173 email requests were placed to waste management
experts in various Floridian counties including Alachua, Baker, Bay, Bradford, Brevard, Broward,
Calhoun, Charlotte, Citrus, Clay, Collier, Columbia, Desoto, Dixie, Duval, Escambia, Flagler,
Gadsden, Gilchrist, Glades, Gulf, Hamilton, Hardee, Hendry, Highlands, Holmes, Indian River,
Jackson, Jefferson, Lafayette, Lake, Lee, Leon, Levy, Liberty, Madison, Manatee, Marion, Martin,
Miami Dade, Monroe, Nassau, Okaloosa, Okeechobee, Orange, Osceola, Palm Beach, Pasco,
Pinellas, Polk, Putnam, Santa Rosa, Sarasota, Seminole, St. Johns, St. Lucie, Sumter, Suwannee,
Taylor, Volusia, Wakulla, Walton, Washington counties.
Experts contacted from given counties come from various backgrounds related to solid waste.
Their backgrounds and job titles include solid waste specialists, solid waste managers,
environmental service directors, public works directors, solid waste recycling coordinators,
hazardous waste professional engineers, recycling coordinators, utility operations directors, solid
waste facility directors, sanitation directors, and environmental managers.
3.2.3 Categorization of Counties
As a third stage of data collection, similar counties are categorized based on their abilities to
manage waste using similar advanced SWM technology. Hence, the categorization of counties into
Gasification
Plasma Arc
Gasification
Pyrolysis
Revenue
Tipping Fees
Capital Cost
Operation/Maintenance
Development Period
Flexibility of Process
Landtake of Facility
Net Conversion Efficiency
Ease of Permitting
Marketability
Environmental Impact
Public Acceptability
Number of Facilities
Criterion Set Alternatives
Figure 5: AHP Structure
different groups is conducted based on the pre-defined factors, including the landfill life cycle,
disposal types, and waste generation. Florida Department of Environmental Protection solid waste
management 2013 annual reports are used to obtain solid waste disposal types, landfill lifecycles,
and waste generation data of each county [10]. The first step is classifying counties based on least
recycled disposal types. Here, the formed groups are then divided into subgroups based on their
annual waste generation amounts.
3.2.3.1 Municipal Solid Waste Types in Floridian Counties
According to United States Environmental Protection Agency (EPA), MSW heavily consists of
everyday items that are discarded by the residents and businesses such as newspapers, office
papers, paper napkins, plastic films, clothing, food packaging, cans, bottles, food scraps, yard
trimmings, product packaging, grass clippings, furniture, wood pallets, appliances, paint, and
batteries [21]. In this work the definition provided by the EPA for MSW is used to categorize the
counties based on the waste types. Waste types that are not considered in categorization of counties
and reasons for not using them are discussed in this section.
For some waste types that are 100% recyclable, recycling technologies are already well established
with their associated markets. For instance non-ferrous metals such as brass, stainless steel, copper,
aluminum are, overall, 100% recyclable and can be easily recovered during the recycling
process. They perform well when used in new products since they retain their properties when
recovered. Moreover, 48% of Floridian counties have a recycling rate greater than 50% for non-
ferrous metals. As such, these wastes do not need to be converted by advanced SWM technologies
and therefore are not considered as part of the categorization.
Construction and demolition (C&D) debris is comprised of waste that is generated during new
construction, renovation, and demolition of buildings, roads, and bridges. C&D debris often
contains bulky, heavy materials that include concrete, asphalt, doors, windows, gypsum, and
bricks. C&D waste is mainly disposed in landfılls that are permitted to accept only C&D waste or
that receive primarily MSW. C&D debris waste includes building related construction,
renovation, and demolition debris whereas non-MSW C&D debris contains roadways, bridges,
and other non-building related C&D debris generation. The largest percentage of C&D debris
generation and recovery is made up of non-MSW C&D debris. In addition, C&D debris has a
separate disposal stream than MSW. For these reasons, C&D debris is also not considered as one
of the waste types to categorize the counties.
3.2.3.2 Floridian County Categories for AHP
The main purpose of using advanced SWM technologies is to reduce the amount of landfilled
waste. For this reason, categorization is performed based on the least recycled waste type in each
county. The counties that have the lowest recycling rates of yard trashes fall into the same group
while the counties that have the lowest recycling rates of various paper waste including newspaper,
office paper, cardboard were collected under another group. AHP calculations are performed for
each group and suggest the same advanced thermal SWM technology for the counties in the same
group. The most widely generated waste type is chosen when more than one type has the lowest
recycling rate.
Three groups, food-yard trash, paper, and plastic trash, are obtained in the first categorization as
these are the three waste types that have the lowest recycling rates in each county. Subgroups are
obtained in the second step based on the waste generation amount of each county.
Grouping procedure is also shown in Figure 6. 2013 Solid Waste Annual Report County MSW
and Recycling Data are used for grouping these counties. The grouping process shown in Figure
6 can be implemented to rearrange the groups as the more annual waste generation data becomes
available.
Waste type which has the
least recycling rate during 2013
Food
FDEP 2013 Solid Waste Annual Report
County MSW and Recycling Data
Paper Plastic
annual waste
generation
annual waste
generation
annual waste
generation
4500 -15,000
15,000-80,000
80,000-400,000
400,000-1,000,000
1 - 3.5 million
10,000-100,000
100,000-700,000
100,000-700,000
Figure 6: Grouping Process of Floridian Counties
Formed county groups are as follows:
Group 1 is formed by Lafayette, Holmes, Liberty, Dixie, Gilchrist, Wakulla, Union,
Hamilton, Madison and Calhoun. They have the least recycling rates for food where their
annual waste generation varies from 4500 to 15,000 tons.
Group 2 consists of Glades, Taylor, Franklin, Desoto, Levy, Washington, Hendry,
Okeechobee, Gadsden and Columbia. They have the second to least recycling rates for
food where their annual waste generation varies from 15,000 to 80,000 tons.
Group 3 consists of Nassau, Walton, Citrus, Flagler, Clay, Okaloosa, Osceola, Marion, Bay
and Alachua. They have the least recycling rates for food and yard trash where their annual
waste generation varies from 100,000 to 400,000 tons.
Group 4 is formed by Escambia, Lake, Manatee, Seminole, Collier, Volusia and Polk. They
have the least recycling rates for food where their annual waste generation varies from
450,000 to 950,000 tons.
Group 5 is formed by Lee, Brevard, Pinellas, Duval, Hillsborough, Orange, Broward and
Dade. They have the least recycling rates for food where their annual waste generation
varies from 1 million to 3.5 million tons.
Group 6 is formed by Jefferson, Baker, Bradford, Jackson, Putnam and Highlands. They
have the least recycling rates for paper product where their annual waste generation varies
from 10,000 to 100,000 tons.
Group 7 is formed by Gulf, Hardee, Suwannee, Charlotte, Sarasota, Indian River, Palm
Beach, Santa Rosa, St. Johns and St. Lucie. They have the least recycling rates mainly for
plastic products where their annual waste generation varies from 15,000 to 300,000 tons.
Group 8 consists of Sumter, Hernando, Monroe, Martin, Leon and Pasco. They have the
least recycling rates for other paper products where their annual waste generation varies
from 100,000 to 700,000 tons.
3.2.4 Technology Data
In the last stage, data for advanced thermal SWM technologies are collected from publicly
available sources and from facilities in the U.S. The Montgomery gasification facility in Orange
County, St. Lucie plasma arc gasification project and JBI Niagara Falls pyrolysis facility are
contacted to obtain the necessary data for technologies. Necessary data are the capital cost and
operation cost of technologies, revenue that the facility obtain by selling the outputs of the process,
tipping fees of the facility, permitting issues of project, efficiency and the flexibility of the process.
4. METHODOLOGY
Our aim in this research project is to assess the emerging advanced SWM technologies for
Floridian counties. Considering SWM literature, AHP is chosen for comparing advanced thermal
SWM technologies and find an optimum technology to manage their wastes for each county. After
advanced SWM technologies are defined, the inputs obtained from solid waste management
divisions of Floridian counties are incorporated into a pairwise comparison matrix to rank the
identified technologies. Our methodology is defined in the following subsections.
4.1 AHP
The AHP method is a strong and effective tool that deals with complex decision making problems
using a set of criteria to find the best alternative [22]. The model is hierarchically structured,
consisting of objectives, criteria, sub-criteria, and alternatives. The criterion set is weighed using
pairwise comparison matrices which are built based on subject matter experts (SMEs) opinion. For
each criterion, alternatives have different performance scores. Global scores are determined by
combining criteria weights and performance scores of alternatives.
After defining criterion set, the first step of an AHP is to weigh them by averaging the SME
opinions. SMEs rank the criterion set based on their importance and the rankings are converted
into values in a 1-9 scale. A 1-9 scale is used to create a pairwise comparison matrix of the criterion
set and is shown in Figure . If activity i has one of the non-zero numbers in 7 assigned to it when
compared with activity j, then j has the reciprocal value when compared with i.
Figure 7: Explanation of 1-9 Saaty Scale
Subject matter expert judgments provided from each county are converted into pairwise
comparison matrices. Aggregation of individual judgments (AIJ) is completed using geometric
mean of corresponding elements. Each matrix element of the consolidated decision matrix is the
geometric mean of corresponding elements of SMEs’ individual decision matrices. The
consolidated matrix is used to compute the global priorities of criteria for each group of counties.
Meanwhile, their consistencies need to be checked in order to achieve a convincing result. In this
study, Expert Choice Decision Support Software is used to establish the AHP model.
5. AHP RESULTS
The next task is to compute the weights of criteria for each group of counties. In this study, criteria
weights are computed using Expert Choice Decision Support Software. Subject matter expert
judgments provided from each county are converted into pairwise comparison matrices.
Aggregation of individual judgments (AIJ) is completed using geometric means. Each matrix
element of the consolidated decision matrix is the geometric mean of corresponding elements of
SMEs’ individual decision matrices. The consolidated matrix is used to compute the global
priorities of criteria for each group of counties. Expert Choice Software uses the consolidated
matrix to compute the weights of criteria. After pairwise comparison matrices are incorporated
into the AHP model, results are obtained from Expert Choice Decision Support Software for each
group. The computed criteria weights are shown in Figure 5.
1 3 5 7 9
Equal Slight Moderate Strong Extreme More Important
Figure 5: Criteria Weights Obtained from Expert Choice (a) Group 1, (b) Group 2, (c) Group 3,
(d) Group 4, (e) Group 5, (f) Group 6, (g) Group 7, (h) Group 8
Using computed criteria weights, gasification, pyrolysis, and plasma arc gasification technologies
are compared. According to AHP results obtained from our model, the optimum alternative with
respect to given criteria set is gasification while the poorest one is the pyrolysis for all groups. The
inconsistency ratio which indicates the amount of inconsistency of comparisons is computed for
each group of counties. Inconsistency ratio below 0.1 mean that the pairwise comparisons are
consistent and do not require revision. Results show that the overall inconsistencies for all groups
are below 0.1 as shown in Figure 6.
Group 1 Group 2 Group 3 Group 4 Group 5 Group 6 Group 7 Group 8
IR 0.03 0.02 0.01 0.01 0.01 0.02 0.01 0.01
0.03
0.02
0.01 0.01 0.01
0.02
0.01 0.01
0
0.01
0.02
0.03
0.04
0.05
0.06
0.07
0.08
0.09
0.1Maximum inconsistency ratio
Figure 6: Overall Inconsistency Ratios (IR) Obtained from Expert Choice Decision Software
(<<0.1)
6. RECCOMENDATIONS
AHP results show that gasification has the highest ranked score for all groups as shown in Figure
7. However, it can be seen that weights of the plasma arc gasification and gasification technologies
for groups 5 and 8 are approximately the same. For these counties capital cost is among the most
important criteria. Plasma arc gasification can be an option for them, if the weight of capital cost
of technology is decreased because plasma arc gasification requires the highest capital cost among
alternatives.
For the first and seventh groups, where the most important criterion is public acceptability, plasma
arc gasification is not a good option unless a public outreach to inform the public about plasma arc
gasification is done. There is still public concern about this technology. The most important
criterion for second group is environmental impact. Gasification and plasma arc gasification
perform similarly on reducing greenhouse gas emissions. Any of these two technologies can satisfy
this criterion well. Revenue is the most important criterion for the third and sixth groups. Plasma
arc gasification brings the highest revenue among alternatives and plasma arc gasification may
serve better to increase revenue in long term. Capital cost is the most important criterion for fourth
group. Hence, gasification is the most viable option providing that counties ranked this criterion
high because of their limited budget.
Counties which are interested in output of the process may select any of alternatives since all of
the thermal technologies generate syngas as output which can be converted into energy. When
technology availability is considered gasification technology has been commercially used
worldwide and vendors also can be found in the U.S. For counties which can collaborate with the
facilities in other countries, plasma arc gasification can also be a viable option.
These evaluations and recommendations provide a robust basis and structural framework for the
counties which will initiate an advanced solid waste management project. Further evaluations can
be built based on this study for conceived SWM projects of Floridian counties.
Group 1 Group 2 Group 3 Group 4 Group 5 Group 6 Group 7 Group 8
Pyrolysis 0.240 0.182 0.206 0.214 0.206 0.213 0.214 0.185
Plasma Arc Gasification 0.243 0.367 0.382 0.37 0.391 0.372 0.322 0.407
Gasification 0.516 0.451 0.412 0.416 0.403 0.415 0.463 0.408
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.50
0.55
Ad
va
nce
d T
her
ma
l S
WM
Tec
hn
olo
gy
Wei
gh
ts
Figure 7: AHP Results for all groups
7. DATA COLLECTION for ABSWM Technologies
7.1 ABSWM Technologies
ABSWM technologies offer the opportunity to process the organic rich fraction of MSW. During
the biological treatment of MSW, biodegradable waste decomposed by living microbes. Aerobic
and anaerobic conditions are two types of environment where microbes are able to live. Organic
portion of MSW should be separated from mixed waste before they are used as feedstock for
ABSWM processes. ABSWM technologies are divided into two major groups as aerobic and
anaerobic processes. Windrow composting, static pile composting, and in-vessel composting are
evaluated under the category of aerobic processes.
7.1.1 Windrow Composting
One of the most prevalently used methods for large scale composting is windrow composting.
Rows of turning piles are the main components of the system. Organic waste is fed into piles as
they turn periodically. Periodic turning reduces the odors while increases the operating costs. The
width and height of the windrows are defined considering several parameters such as feedstock
characteristics and aeration conditions. They are open systems. Thus they can easily be affected
by the weather changes. Information obtained during the WasteCON 2015, it takes 8 to 12 months
to produce a compost.
7.1.2 Static Pile Composting
They are similar to windrow systems however, they do not need to be turned. Due to this fact, they
can be larger than windrows. They can process large amounts of waste since they can be designed
in larger capacities. Their process parameters should be monitored and controlled closely to
provide the distribution of heat over the system.
7.1.3 In-vessel Composting
In vessel composting systems are closely monitored aeration systems which produces compost in
an enclosed container such as reactor. Their appearances are similar to anaerobic digestion
facilities. The most important advantage they provide is that the system temperature, moisture, and
other parameters can be closely controlled. However, they have high capital and operating costs.
Emissions are less than windrow composting due to their closed system design.
7.1.4 Anaerobic Digestion
Anaerobic digestion (AD) of MSW involves conversion of biodegradable waste into water and
biogas by microbes in the absence of oxygen. The process is performed in an indoor vessel. Process
is performed in three major stages: hydrolysis, acetogenesis, and methanogenesis. First insoluble
portion of organic matter is hydrolyzed into soluble molecules. Secondly, the outputs of first step
is converted into carbon dioxide, hydrogen and simple organic acids. Lastly, methane formers
produce methane.
The optimal process temperature is around 30-35oC. Anaerobic digestion can be classified based
on the number of reactors used: single or multiple reactors. In multistage systems, hydrolysis takes
place in a separate vessel. In multistage systems, process parameters can be customized in each
stage but they have higher capital costs.
7.2 Data Collection Stages
In this quarterly period, ABSWM technologies are evaluated for different counties in Florida. Data
collection is composed of four stages. In the first stage, the criteria set are defined for AHP. SMEs
rankings obtained for the evaluation of ATSWM technologies were used for ABSWM technology
evaluation as well. Previously formed county categories were used for the evaluation of ABSWM
technologies.
7.2.1 Defining Criteria Set
The set of criteria was customized for the evaluation of ABSWM technologies. Capital cost,
operating cost, operation time, land requirements of the facility, conversion efficiency,
environmental impact, and public acceptance were taken into consideration. For the rest of the
criteria, ABSWM technology performances were very close and the difference were negligible.
Due to this fact, they were not taken into consideration. AHP structure for explored ABSWM
technologies and defined criterion set is built and given in Figure 8.
In the second stage of data collection, criteria weights are determined after contacting SWM of
Floridian counties and Florida Department of Environmental Protection through email
communication. Criteria weights for each group of counties can be seen in Figure 9.
Alternatives
Windrow
Composting
Static Pile
Composting
In-vessel
Composting
Capital Cost
Operating Cost
Land Requirement
Operation Time
Public Acceptance
Efficiency
Environmental Impact
Criteria Set
Selecting an
Appropriate
ABSWM
Technology
Goal
Anaerobic
Digestion
Figure 8: AHP Structure for ABSWM Technology Evaluation
8. AHP RESULTS
Using computed criteria weights, ABSWM technologies are compared. The inconsistency ratio
which indicates the amount of inconsistency of comparisons is computed for each group of
counties. Inconsistency ratio below 0.1 means that the pairwise comparisons are consistent and do
not require revision. Results show that the overall inconsistencies for all groups are below 0.1 as
shown in Figure 10.
Figure 10: Overall Inconsistency Ratios (IR) Obtained from Expert Choice Decision Software
(<<0.1)
9. RECCOMENDATIONS
AHP results show that static pile composting has the highest global weight for Group 5, in-vessel
composting has the highest global weight for Groups 1 and 7, anaerobic digestion has the highest
global weight for Groups 2,3,4,6, and 8 as can be seen in Figure 11. Results for the evaluation of
ABSWM technologies are not similar to results obtained from the evaluation of ATSWM
technologies. This must be because ATSWM technologies are very similar and their main
difference is the process temperatures.
Figure 11: Figure 12: AHP Results for All Groups of Counties
0
0.02
0.04
0.06
0.08
0.1
Group 1 Group 2 Group 3 Group 4 Group 5 Group 6 Group 7 Group 8
IR
Group 1 Group 2 Group 3 Group 4 Group 5 Group 6 Group 7 Group 8
Windrow composting 0.130 0.125 0.151 0.158 0.170 0.157 0.135 0.154
Static pile composting 0.214 0.216 0.250 0.276 0.297 0.268 0.238 0.267
In-vessel composting 0.374 0.282 0.289 0.254 0.246 0.281 0.334 0.275
Anaerobic digestion 0.282 0.377 0.310 0.313 0.287 0.295 0.293 0.304
0.0
0.1
0.2
0.3
0.4
0.5
Ad
van
ced
Bio
logic
al
Con
ver
sion
Tec
hn
olo
gy W
eig
hts
In the next quarterly report, recommendations will be given based on the results obtained from
AHP models and the current waste management capacities of counties. These evaluations and
recommendations provide a robust basis and structural framework for the counties which will
initiate an advanced solid waste management project. Further evaluations can be built based on
this study for conceived SWM projects of Floridian counties.
10. OTHER TECHNOLOGIES
Steam classification, hydrothermal carbonization, catalytic cracking, and depolymerization
technologies were not evaluated in this study. They are not commercially used for processing
MSW. However, there are demonstration facilities for steam classification in California and for
hydrothermal carbonization in Germany. Facilities were contacted during this quarterly period, but
information needed for our evaluation was not provided by them.
PROGRESS AND THE FUTURE WORK
Task I: Assessment of Advanced Solid Waste Management Technologies (%100 complete)
In this study, we propose to identify and evaluate the new and emerging solid waste management
and recycling technologies and their potential benefits to various Floridian counties in order to
help the State reach its 75% recycling goal by 2020. For the purposes of this evaluation study,
“new and emerging technologies” are defined as technologies (e.g., biological, chemical,
mechanical and thermal processes) that are not currently in widespread commercial use in the State
of Florida, or that have only recently become commercially operational [21] [32]. During second
quarterly period, advanced thermal SWM technologies are identified as gasification, plasma arc
gasification and pyrolysis. Required data to perform AHP are collected and commercial status of
regarding these technologies are assessed. During third quarterly period, advanced biological
SWM technologies are identified as windrow composting, static pile composting, in-vessel
composting, and anaerobic digestion. Required data to perform AHP are collected and commercial
status of regarding these technologies are assessed.
Task II: Data Collection Technologies (%100 complete)
Various data regarding the advanced thermal and biological SWM technologies are collected by
utilizing multiple data collection techniques. Data are collected by reviewing materials and
interviewing. Waste management literature is collected from on-line databases at University of
Miami and County Waste Management Plans is collected from Florida Department of
Environmental Protection and County government websites. In order to implement AHP, we have
contacted to solid waste management divisions of each county. 173 email requests for evaluation
of criterion set by SMEs are sent to all Floridian Counties. Site visits will also be conducted to
several Floridian counties. Conversion technology division manager of Salinas Valley Solid Waste
Authority was contacted to obtain information for Autoclaving Technology Testing Program. The
Montgomery gasification facility in Orange County and JBI Niagara Falls pyrolysis facility are
contacted to obtain the necessary data for technologies. Plasma arc gasification data are obtained
the online documents provided for St. Lucie plasma arc gasification project. Hydrothermal
carbonization, steam classification, depolymerization, and catalytic cracking technologies were
searched from publicly available sources. No data were available related to the set of criteria and
no commercial scale facility were found in the U.S. These technologies were not evaluated due to
the comments obtained during the first TAG meeting.
Task III: Comparative Evaluation of Advanced Thermal SWM Technologies (100%)
In this study, the Analytical Hierarchy Process (AHP) is chosen as the qualitative decision making
tool in selection of the appropriate technologies for different communities in the State of Florida.
The model is hierarchically structured, consisting of objectives, criteria, sub-criteria, and
alternatives. Based on several pre-defined criteria such as environmental impact, market potential,
public acceptability, development period, etc., the analysis provides a priority lists for these
technologies as an output. In this reporting period, AHP is conducted to assess gasification, plasma
arc gasification, pyrolysis, windrow composting, static pile composting, in-vessel composting, and
anaerobic digestion technologies for 67 counties in Florida. Expert Choice Decision Support
Software is used for analysis. SME opinions and data for technologies are incorporated into the
software and results give the most optimum thermal and biological technologies to be implemented
for each group of county.
Task IV: Recommendations (80%)
Combining obtained quantitative and qualitative findings (through the output obtained from the
AHP analysis), final recommendations are provided. These recommendations are developed for
the State of Florida and its counties considering various factors costs, required operational
expertise, public acceptance/opposition, environmental impacts, and implementation feasibilities.
State-wide recommendations are provided considering the potential wide audience of this study
including various stakeholders of the solid waste industry, city officials, private companies, solid
waste practitioners, waste generators (residential and commercial), environmental agencies, and
communities at large.
APPENDIX A: SELECTED DOCUMENTS REVIEWED
[1] Global Waste Management, Market Report, 2007.
[2] Sakai S, Sawell SE, Chandler AJ, Eighmy TT. World trends in municipal solid waste
management. Waste Manage 1996;16(5–6):341–50.
[3] Florida Research and Economic Information Database Application Website, Accessed March
2015.
[4] Belevi H, Baccini P. Long-term behavior of municipal solid waste landfills. Waste Manage
1989;7(1):43–56.
[5] Kristina H. Role of a district-heating network as a user of waste-heat supply from various
sources - the case of Goteborg. Appl Energy 2006;83(12):1351–67.
[6] Marcelo RH, Jose A, Perrella B. Cogeneration in a solid-wastes power-station: acase-study.
Appl Energy 1999;63(2):125–39.
[7] Gordon M. Dioxin characterisation formation and minimisation during municipal solid waste
(MSW) incineration: review. Chem Eng J 2002;86(3):343–68.
[8] Suksankraisorn K, Patumsawad S, Fungtammasan B. Combustion studies of high moisture
content waste in a fluidised bed. Waste Manage 2003;23(5):433–9.
[9] Carlton CW. Municipal solid waste combustion ash: State-of-the-knowledge. J Hazard Mater
1996;47(1–3):325–44.
[10] Solid Waste Management in Florida Annual Report, 2013. Available online at:
http://www.dep.state.fl.us/Waste/categories/recycling/SWreportdata/13_data.htm
[11] Hokkanen, J., and Salminen, P. 1997. Choosing a solid waste management system using
multi-criteria decision analysis, European Journal of Operational Research, 98 (1), 19-36.
[12] Schell, C., and Liu, A., 2009. Canada Solid Waste Disposal Equipment, Report submitted to
U.S. Commercial Service in Vancouver, Canada.
[13] Antmann, E.D., Shi, X., Celik, N., and Dai, Y.D., 2011. Continuous-discrete simulation-based
decision making framework for solid waste management and recycling programs, Computer
and Industrial Engineering, 65(3), 438-454.
[14] Regional Municipality of Halton, 2007. EFW Technology Overview. Technical Report.
Available online at: [www.halton.ca/common/pages/UserFile.aspx?fileId=17470]
[15] Heermann C., Schwager F.J., Whiting K.J., 2001. Pyrolysis and Gasification of Waste: A
Worldwide Technology and Business Review. Juniper Consultancy Services.
[16] Gamble, S. and Alexander, R., 2009. Integrated Resources and Solid Waste Management
Plan. Technical Memorandum prepared for County of Hawaii. Available online at:
[http://www.hawaiizerowaste.org/uploads/files/IRSWMP_Appendixes_Dec2009.pdf]
[17] City of Los Angeles, 2005. Summary Report: Evaluation of Alternative Solid Waste
Processing Technologies. USR Corporation.
[18] Chen Y, Cheng JJ, Creamer KS. Inhibition of anaerobic digestion process: a review.
Bioresource Technology 2008;99(10):4044–64.
[19] Guddeti, R. R. (2000). Depolymerization of the waste polymers in municipal solid waste
streams using induction-coupled plasma technology.
[20] Department for Environment Food & Rural Affairs, 2013. Advanced Biological Treatment of
Municipal Solid Waste. Available online at:
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/221037/pb13
887-advanced-biological-treatment-waste.pdf
[21] Wastes-Municipal Solid Waste: United States Environmental Protection Agency; [updated
2/28/2014; cited 2015 5/22/2015]. Available from:
http://www.epa.gov/epawaste/nonhaz/municipal/.
[22] Saaty, T. L. The Analytic Hierarchy Process: McGraw-Hill, New York; 1980.