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

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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

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d T

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WM

Tec

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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

Figure 9: Criteria Weights for the Evaluation of ABSWM Technologies

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

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0.4

0.5

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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.