United States
Environmental Protection
Agency
Air and Energy Engineering
Research Laboratory
Research Triangle Park, NC 27711
Research and Development
EPA/600/SR-95/035
May 1995
EPA Project Summary
Landfill Gas Energy Utilization
Experience: Discussion of
Technical and Non-Technical
Issues, Solutions, and Trends
Michiel Doom, John Pacey, and Don Augenstein
Clean Air Act (CAA) regulations for
new and existing municipal solid waste
landfills are expected to require ap-
proximately 500 to 700 sites to install
and maintain a landfill gas extraction
and control facility to reduce landfill
emissions, which include nonmethane
organic compounds, toxics, and green-
house gases. The Air and Energy Engi-
neering Research Laboratory (AEERL)
of the U.S. Environmental Protection
Agency (EPA) is conducting ongoing
research to provide information on en-
ergy conversion options for landfill gas
utilization as a means of assisting land-
fill owner/operators that may be affected
by the CAA regulations.
This report is a follow-on to a 1992
publication that provides information
on the different options for landfill gas
utilization that are illustrated by case
studies. The focus of this new report is
on technical and non-technical consid-
erations associated with the develop-
ment and operation of landfill gas to
energy projects. Much of the informa-
tion used to generate this report is from
interviews and site visits with the ma-
jor developers and operators of the
more than 110 projects in the U.S. This
report also provides the history and
trends of the landfill gas industry in
the U.S. Graphs illustrate how the in-
fluence of reciprocating internal com-
bustion (RIC) engines, compared to
other utilization options, has steadily
increased over time.
Landfill gas is a medium heating
value fuel (approximately 500 Btu/scf
or 19 MJ/m3), and can contain corro-
sive compounds and particulates. The
gas may be used in direct heating ap-
plications (i.e., boilers or kilns), in re-
ciprocating engines and turbines to pro-
duce electricity, or it may be purified to
pipeline quality gas, or for use in fuel
cells. This report identifies the poten-
tial difficulties that may be encountered
in developing a landfill gas to energy
project and presents possible solutions
that have been found through the ex-
perience of the landfill gas to energy
industry. Possible remedies to typical
technical landfill gas issues addressed
in this report are 1) material modifica-
tions, 2) condensate management, 3)
use of special oils (in RIC engines),
and 4) engine adjustments (in RIC en-
gines).
Some of the non-technical problems
and solutions described in this report
are associated with the development
of energy utilization options including
project economics, barriers, and incen-
tives. Two new programs that may pro-
vide incentives are described. The in-
formation presented on non-technical
barriers is primarily based on the ex-
perience of private U.S. landfill gas
project developers and operators and
is not intended to give a comprehen-
sive overview of all perspectives on
landfill gas utilization.
Ongoing research by EPA and oth-
ers is aimed at tracking and develop-
ing new options for landfill gas utiliza-
tion. This report summarizes informa-
tion on new landfill gas utilization tech-
nologies, including vehicular fuel sys-
tems and fuel cells. Overall results of
-------
programs to demonstrate the opera-
tional feasibility of innovative technolo-
gies appear quite promising. For ex-
ample, the fuel cell technology for land-
fill gas has many potential advantages
over conventional technologies includ-
ing its high energy efficiency, minimal
by-product emissions, and minimal la-
bor and maintenance. The use of fuel
cells may be economically feasible be-
fore the turn of the century.
This Project Summary was developed
by EPA's Air and Energy Engineering
Research Laboratory, Research Tri-
angle Park, NC, to announce key find-
ings of the research project that is fully
documented in a separate report of the
same title (see Project Report ordering
information at back).
Technical Considerations
This section discusses the technical is-
sues associated with the use of landfill
gas compared to natural gaswhich is
the primary fuel used for energy conver-
sion equipment such as reciprocating en-
gines, gas turbines, and fuel cells. This
section reviews these technical issues and
summarizes current field experience in
minimizing their effects. To obtain prag-
matic and recent information, interviews
were conducted with five developers and/
or operators of landfill gas energy projects
and one engine manufacturer.
Technical issues arise as a result of the
relatively low heating value or from the
presence of chlorinated and toxic com-
pounds, particulates, as well as the for-
mation of condensates or deposits. [For
landfill gas the heating value is approxi-
mately 19 MJ/m3 and for natural gas it is
approximately 37 MJ/m3 (500 vs. 1,000
Btu/scf).] Possible remedies to typical tech-
nical landfill gas issues addressed in this
report are 1) material modifications, 2)
condensate management, 3) use of spe-
cial oils (in RIC engines), and 4) engine
adjustments (in RIC engines).
The section presents four simplified pro-
cess flow charts illustrating approaches to
landfill gas cleanup for utilization projects.
Non-Technical Considerations
This section discusses non-technical
barriers that are associated with landfill
gas recovery and utilization as encoun-
tered by the landfill gas utilization indus-
try. Also, incentives and government ini-
tiatives to encourage landfill gas utiliza-
tion are described. To obtain pragmatic
and recent information, interviews were
conducted with seven developers and/or
operators of landfill gas energy projects.
U.S. barriers that were identified from
the interviews conducted for this report
include:
Unfavorable economics due to low
energy prices and high debt service
rates for landfill gas-to-energy projects
that generate electricity or pipeline
quality gas;
Limited or unstable marketplace;
Obtaining third party project financing
at reasonable cost, because it is diffi-
cult, time consuming, and proportion-
ately more costly for small projects
than for large projects;
Difficulties in obtaining air permits,
especially for projects located in
ozone, nitrogen oxide (NOx), and car-
bon monoxide (CO) nonattainment ar-
eas, because air boards and utilities
often have lengthy permit processes
and contract negotiations;
Difficulties in negotiating power con-
tracts with local utilities because they
are primarily interested in purchasing
low-cost power without considering
environmental externalities (e.g., off-
sets from power plants using fossil
fuel). [However, the environment has
changed somewhat as a consequence
of State Public Utility Commissions
(PUCs) who mandate that utilities pay
only avoided cost for electricity pur-
chases];
Unforeseen costs resulting from com-
pliance with new air quality rules and
regulations, and declining energy rev-
enues that cannot be adjusted to off-
set new costs;
Taxation by some states (e.g., Cali-
fornia) on landfill gas extraction and
energy conversion facilities; and
Difficulties in understanding federal
and state energy policies and envi-
ronmental regulations that may affect
these projects.
U.S. incentives for undertaking landfill
gas projects include:
Purchase of electricity at avoided cost
of between 2.5 and 3.0 cents/kWh,
except where a utility offers a special
incentive program, consisting of a
levelized higher price, and/or capac-
ity entitlement,
Production Tax Credits (PTCs),
Favorable utility contracts for electric-
ity projects,
Tax exemptions for landfill gas ex-
traction and energy conversion facili-
ties,
Technical assistance from EPA's Con-
trol Technology Center, and
New initiatives such as the Depart-
ment of Energy's research, develop-
ment, and demonstration program
(RD&D Program) targeted at the tech-
nical barriers to landfill methane (CH4)
energy recovery and EPA's Landfill
CH4 Outreach Program that is de-
signed to remove regulatory, informa-
tion, and other barriers.
Emerging Technologies
Emerging technologies are discussed
in this report:
Landfill gas utilization as vehicular fuel
(demonstration project),
Conversion of landfill gas to metha-
nol (demonstration plant under con-
struction),
Landfill gas utilization in fuel cells
(demonstration project),
Rankine cycle converters (field tests
have been conducted to recover
waste heat from landfill gas flares),
and
Stirling engines (no landfill gas expe-
rience to date).
Most experience to date has been on
fuel cell applications to landfill gas. The
EPA initiated a research and development
project in 1991 to evaluate the use of
commercially available fuel cells for land-
fill gas applications, because of the poten-
tial environmental and energy efficiency
characteristics, which include a higher en-
ergy efficiency (to 40%), minimal by-prod-
uct emissions, and minimal labor and main-
tenance requirements.
The major technical consideration as-
sociated with the application of fuel cells
to landfill gas projects is the gas cleanup
system. Testing of EPA's cleanup system
has just been completed, resulting in over
200 hours of successful operation. The
gas cleanup system is designed to clean
the gas to 3 ppmv of chlorides and 3
ppmv of sulfur. Next, a 1-year demonstra-
tion is planned to study the performance
of fuel cells for landfill gas energy conver-
sion applications. The major non-techni-
-------
cal consideration associated with fuel cells Attributes of various proven technolo- policy that regards landfill gas to en-
has been the capital cost. gies for generating electricity while ergy projects as potential pollution pre-
A Oth utilizing landfill gas as a fuel, vention sources, and
Information ' Landfi" gas turbines> Non-technical issues such as the sale
The reoort includes other material that ' A demonstration project to convert of electricity from landfill gas projects
I he report me udes other material that d a|ternative energy regu|atory poli-
is geared to the landfill gas industry. Van- idiiunn ydb miu vemue mei, a* a 3 K
ous appendices provide information on: An EPA memo dated July 1994 pro-
International landfill gas experience, viding the EPA's New Source Review
-------
MichielDoom is with E. H. PechanandAssoc., Inc., Durham, NC27707; John Pacey
is with F.H.C., Inc., Pebble Beach, CA 93953; and Don Augenstein is with I.E.M.,
Palo Alto, CA 94306.
Susan A. Thorneloe is the EPA Project Officer (see below).
The complete report, entitled "Landfill Gas Energy Utilization Experience: Discus-
sion of Technical and Non-Technical Issues, Solutions, and Trends," (Order No.
PB95-188108; Cost: $36.50, subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Air and Energy Engineering Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park, NC 27711
United States
Environmental Protection Agency
Center for Environmental Research Information
Cincinnati, OH 45268
Official Business
Penalty for Private Use $300
BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35
EPA/600/SR-95/035
------- |