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OAR Box 1781 

Prepped by Ollie Stewart 

Document Number: 

13)11-1-5 

Docket Number: 

A-90-37 

Printed 10/29/2008 10:46:18 AM Sheet 13 of 142 
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^!L!% UNITED STATES ENVIRONMENTAL PROTECTION AGENCY 

OFFICE OF RESEARCH AND DEVELOPMENT 

AIR AND ENERGY ENGINEERING RESEARCH LABORATORY 

RESEARCH TRIANGLE PARK, NORTH CAROLINA 27711 

DATE: August 31, 1993 

SUBJECT: Comments on Chapter 4, "Opportunities To Reduce Methane 

Emissions from Landfills" from Report to Congress - Opportunities 

To Reduce Methane Emissions in The United States" 

FROM: Susan A. Thorneloe (MD 63) ^ 

Global Warming Control Branch 

Global Emissions & Control Division 

TO: Stan Durkee (H 8105) 

Office of Science Planning & Regulatory Evaluation 

As you requested, I have reviewed the draft report that is in Red Border 

Review. I have a number of concerns about the landfill chapter. My main 

concern is that it gives the impression that utilization is relatively easy when this 

is not the case. There are a number of barriers (or disincentives) that are 

occurring. I think this needs to be more emphasized in the report. Hopefully by 

identifying these barriers, Congress can initiate steps that will lead to developing 

policies that will help to minimize some of the existing barriers. 

Provided below is a list of our comments. Also attached is a paper on the 

benefits and barriers associated with landfill gas utilization. I think the 

information provided in this paper would be of help in OAIAP's revision of this 

chapter. Also attached is a mark-up of some of the pages from the draft chapter. 

Do not hesitate calling me at (919) 541-2709 if I can be of further assistance. 

1. Given the uncertainty associated with the estimate of methane emissions, three 

significant figures is not accurate. 

2. There is a discrepancy between the ORD estimate and the OALAP estimate of 

methane emissions from landfills in the U.S. The ORD estimate is 9 to 19 Tg/yr 

as compared to OAIAP's estimate which is 8 to 12 Tg/yr. We are behind in 

getting our final estimate published due to my illness but it should be published 

this fall. We have included the estimate in the OPPE Report to Congress on 

International Methane Emissions. 
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3. There are several statements that speak in generalities about methane recovery 

that are not factual. For example, page 4-2 states that it is technically feasible to 

recover 85% of LF emissions, it is profitable to recover only about 50-60% of 

landfill methane emissions at an electricity price of $0.05 per kWh. Most of the 

industry does not claim profitability unless they can obtain $0.06 - 0.08 per kWh. 

Also there are a number of factors that can affect the project in addition to 

economics. Although project economics are important, other factors can 

ultimately decide a project's fate. For instance, States are viewing these projects 

as an emission source as opposed to a pollution prevention source. Consequently, 

projects are not being permitted or developed so that New Source Review or 

other applicable regulations are not triggered. 

Just last week I received a call from Waste Management about a large project that 

they had proposed in the State of Illinois. They had hoped to install 2 gas 

turbines. The State denied the permit due to concern for NOx emissions. 

Apparently the State did not allow offsets to be considered. This project was 

marginally economical but with the air permit being denied, it is not being 

developed. 

I am also aware of other projects that are constrained by either NOx or CO 

emission limits and consequently are not utilizing all of the gas that is being 

generated. There are also projects constrained by power contracts and are not 

utilizing all of the gas being generated. These factors are inhibiting landfill gas 

to energy projects. The Air and Energy Engineering Research Laboratory in 

association with the Solid Waste Association of North America is collecting 

information about the different projects in the U.S. so that we have a better 

understanding of these projects including the barriers affecting landfill gas 

utilization. 

The point that we would like to make is that there are other factors as important 

or more important than economics that affect the viability of these projects. We 

are working with OAQPS to see that these kinds of projects get considered as 

pollution prevention projects so that States will hopefully more favorably 

consider these projects since they do result in a number of benefits including 

reduction of methane, VOC, toxics and conservation of our global fossil fuel 

resources. 

4. TTThere are several statements in this chapter that we feel are overly simplistic 

as to landfill gas utilization. Such as "The profitability of recovering and using 

LFG depends upon the amount of gas produced and its value." The information 

in the EPA report that is referenced in this chapter (Landfill Gas Energy 

Utilization: Technology Options and Case Studies, June 1992) was collected to 
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help illustrate the different factors affecting landfill gas utilization. The 1992 

report identifies the different factors such as the trace constituents in the gas that 

determine clean-up requirements, moisture content of the gas and its 

characteristics that determine type of piping and well materials to be used (some 

sites have gone to stainless steel which greatly impacts the cost of the installation), 

dilution of gas and performance effects, and load factor. There are also non 

technical issues including the permitting requirements, applicable emission 

restrictions, power contract restrictions, and liability requirements. 

A project in Virginia shut down due to problems with moisture and gas clean up 

difficulties. A project in Maryland had an engine seize after only 500 hours of 

operation. This impacted the economics. We can provide other examples if you 

would like. 

5. We would like to see how the value on page 4-5 is derived which is the value 

of recovering landfill methane emissions. 

6. We appreciate that pages 4-7 and 4-8 give an overview of four of the six sites 

featured in the case studies. However, it was our intent to show the real life 

difficulties associated with landfill gas to energy projects. These are considered 

successful projects but it has not been easy as the case studies illustrate. I think 

this kind of information is important to include to the Report to Congress so that 

they have a better understanding of the barriers both technical and nontechnical. 

7. We think the barrier section needs to be expanded to cover some of the ideas 

offered above. The power contracts to result in constraints as due to emission 

limits for NOx and CO. Although fuel cells could meet these emission limits, 

they are roughly twice the price of technology in use today. Consequently, 

somehow we need to adopt some sort of system that would allow for offsets or 

consideration of these factors. Typically projects are built based on the lowest 

BID and there is not any kind of consideration of these other factors such as 

higher energy efficiency. 

8. It is not clear how profitability is defined for Exhibit 4-7. As we tried to point 

out above there are factors other than just the buyback rate that affect the 

economics of a project. 

9. The GAA yearbook is frequently cited. Please be aware that there are many 

problems with this database. Consequently, SWANA in conjunction with EPA's 

AEERL are working to develop a database that will provide more reliable 

information for the U.S. landfill gas industry. The first version of this database 

was published in reference 1992d. 
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10. This chapter seems very long. Some of the information seems repetitious. 

For example, the information presented on page 4-8 and 4-9 on barriers is 

repeated on pages 4-47 and 4-48. We also found other information is repeated in 

the chapter that could be consolidated helping to shorten the chapter. 

3 Attachments 

cc: Dennis Doll, OAQPS 

Dennis Drehmel, AEERL 

Bob Hangebrauck, AEERL 

Bill Lamason, OAQPS 

Mike Maxwell, AEERL 

Blair Martin, AEERL 

Frank Princiotta, AEERL 

Lowell Smith, OEPER 
CHAPTER 4 

OPPORTUNITIES TO REDUCE METHANE EMISSIONS FROM LANDFILLS 

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Landfill Methane Emissions Reductions 

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Landfill Methane Emissions (Tg) 

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Emissions with Profitable 

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8.1-11.8 

8.8-12.7 

9.5-13.4 

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1.6-2.2 

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(1.8-4.8)d (9.5-11.3)e 

a Source: USEPA (1993) Baseline emissions reflect methane recovery of 1.5 Tg per yaar throughout the 

period examined. 

b Technically feasible emissions reduction estimated at 85 percent of emissions in the absence of any 

recovery projects. 

c Range of estimates based on an electricity sales price of $0.05 per kWh. 

d Range of estimates based on an electricity sales price of SO 06 per kWh. 

• Range of estimates based on an electricity sales price of $0.04 per kWh. 

4.1 SUMMARY 

Landfills are the largest anthropogenic source of methane emissions in the United 

States. In 1990 landfills emitted an estimated 8.1 to 11.8 Tg to the atmosphere (USEPA 

1993). These emissions represent a substantial amount of energy and are equivalent to 

about 5,000 to 7,500 MW of electric generating capacity. In the absence of efforts to reduce 

.. emissions, landfill methane emissions are expected to grow to between 9.5 to 13.4 Tg per 

Review Draft • July 1993 • Do Not Cite or Quote Page 4-1 
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produces electricity. The advantages of steam turbines are high electric generating efficiency 

and relatively low air pollutant emissions. The disadvantage of steam turbines is that they 

require an extremely large quantity of gas to operate and so are suitable only for a handful ot 

the very largest landfills. 

Other Utilization Options 

Sale as a Medium-BTU Fuel. If the landfill is located near suitable industrial facilities 

the gas can be transported via pipeline and sold as a "medium-BTU" fuel.3 An ideal mediumBTU gas customer would be located near the landfill and would have a nearly continuous 

demand for gaseous fuel. Landfill gas customers may use the gas to fuel a cogeneration 

system, to fire boilers or chillers, or to provide space heating. 

Fuel Cells. A fuel cell converts the chemical energy of the methane directly into 

usable energy as electricity and heat. The advantages of fuel cells include: high energy 

efficiency; low by-product emissions; limited noise production; minimal labor requirements; 

and modularity. The disadvantage of fuels cells is their high cost. However, the cost of fuel 

cells is expected to decrease enough to be competitive with other methods of generating 

electricity. Fuel cells hold great promise as a future option for using landfill gas. 

Production of Liquid Fuels and Industrial Chemicals. Recent developments in 

alternative fuels have led to the improvement of a process that converts landfill gas into 

diesel, naphtha, and high grade industrial waxes. The advantage of producing these 

products is that the economic benefits do not depend on the local electric power system or 

on proximity to a suitable industrial customer. The disadvantage of producing these products 

Is high cost that makes them not competitive with conventional liquid fuels. 

Flaring. Flaring is the simplest way to eliminate landfill gas. The advantage of flaring 

is that the cost is small compared to energy recovery systems. The disadvantage is that 

flaring produces no income for the landfill. 

4.1.4 Current Recovery and Utilization Projects 

There are about 100 landfill gas recovery and utilization projects operating in the U.S. 

(GAA-499T). The following are a few examples of successful projects. 

^U^fJbt. , HitReciprocating Engine • Marina, CA. The Marina project began operation in December 

1983 and is one of the oldest landfill gas recovery and utilization projects in the United States 

The landfill opened in 1966 and contains about four million tons of waste. The recovery 

system consists of 12 vertical wells and seven horizontal trenches. About 900,000 cubic feet 

of gas are collected per day. The gas powers a Waukesha 12-cylinder IC engines that turns 

two generator sets that together produce 1.2 MW of power (USEPA 1992c; USEPA 1992d). 

Combustion Turbine • San Diego, CA. The Sycamore Canyon Landfill is located near 

San Diego, California. The landfill opened in 1962 and has nearly nine million tons of waste 

in place. The collection system consists of 50 vertical wells that collect about 1,200,000 cubic 

3

 A medium BTU fuel has an energy content between 400 to 600 BTU/ft3. By contrast a high BTU fuel such as 

natural gas has an energy content of about 1,000 BTU/tt3 

Review Draft • July 1993 - Do Not Cite or Quote Page 4-7 
P.8 

USEPA (Unrted States Environmental Protection Agency) 1991b. EPA Docket Number A-B8-09 

Document Number ll-B-45, Memorandum from Kathleen Hogan, Chief, Methane 

Programs to Alice Chow, Office of Air Quality Planning and Standards, "Analysis of 

Profits and Cost from Regulating Municipal Solid Waste Landfills," March 28,1991. 

USEPA (United States Environmental Protection Agency) 1992a. "Characterization of 

Municipal Solid Waste In the Unrted States: 1992 Update." EPA Office of Solid Waste 

and Emergency Response, Washington, D.C. EPA/530-R-019, July 1992. 

USEPA (Unrted States Environmental Protection Agency) 1992b. "Development of an Empirical 

Model of Methane Emissions from Landfills." Air and Energy Engineering Research 

Laboratory, Research Triangle Park, NC EPA 600/R-92-037, March 1992. 

'USEPA (Unrted States Environmental Protection Agency) 1992c. "Landfill Gas Energy 

Utilization: Technology Options and Case Studies," prepared by the Air and Energy 

Engineering Research Laboratory, US EPA, Research Triangle Park, NC 27711, EPA600/R-92-116. June 1992. 

USEPA (United States Environmental Protection Agency) 1992d. "Landfill Gas 

Recovery/Utilization - Options and Economics" prepared by the Global Emissions and 

Control Division, Air and Energy Engineering Research Laboratory, US EPA, Research 

Triangle Park, NC 27711, March 5,1992. 

USEPA (Unrted States Environmental Protection Adency) 1993. "Anthropogenic Methane 

Emissions in the United States - Report tbjcongress," prepared by Global Change 

Division, Office of Air and Radiation, US EPA, Washington, DC. 

Williams, R.A. and E. Larson. 1989. "Expanding/Roles for Gas Turbines in Power 

Generation," in Electricity: Efficient End-Use and New Generation Technologies, and 

Their Planning Implications, Lund Unive/sity Press. Sweden. 1989. 

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^yA^tX^ SMJ> D^U ^V ^ ,5~*-TMI 

Review Draft - Jury 1993 - Do Not Cite or Quote Page 4 50 
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Landfill Gas Recovery/Utilization 

Options and Economics 

Susan A. Thorneloe (MD-63) 

(Jlobal Emissions and Control Division 

Air and Energj Engineering Research Laboratory 

U. S. Environmental Protection Agency 

Research Triangle Park, North Carolina 27711 

Presented at: 

The Sixteenth Annual Conference 

bv the Institute of Gas Technology 

on 

Energy from Biomass and Wastes 

Orlando, Florida 

March 5, 1992 
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Landfill Gas Utilization -

Options, Benefits, and Barriers 

Susan A. Thorneloe (MD-63) 

Global Emissions and Control Division 

Air and Energy Engineering Research Laboratory 

U. S. Environmental Protection Agency 

Research Triangle Park, North Carolina 27711 

Presented at: 

The Second United States Conference on 

Municipal Solid Waste Management 

at 

Hyatt Regency Crystal City 

Arlington, VA 

June 3 - 5, 1992 
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&EPA 

United Steles 

Environmental Protection 

Agency 

Research and 

Development 

EPA-600/R-92-116 

June 1992 

LANDFILL GAS 

ENERGY UTILIZATION: 

TECHNOLOGY OPTIONS 

AND CASE STUDIES 

Prepared for 

Office of Air and Radiation 

and 

Office of Policy, Planning and Evaluation 

Prepared by 

Air and Energy Engineering Research 

Laboratory 

Research Triangle Park NC 27711 

*»JJI am