U.S. patent application number 13/072264 was filed with the patent office on 2011-07-21 for methods of reducing greenhouse gases in landfills and coal mines.
This patent application is currently assigned to HEARTLAND TECHNOLOGY PARTNERS LLC. Invention is credited to Craig Clerkin, Bernard F. Duesel, JR., Michael J. Rutsch.
Application Number | 20110178961 13/072264 |
Document ID | / |
Family ID | 44121845 |
Filed Date | 2011-07-21 |
United States Patent
Application |
20110178961 |
Kind Code |
A1 |
Duesel, JR.; Bernard F. ; et
al. |
July 21, 2011 |
METHODS OF REDUCING GREENHOUSE GASES IN LANDFILLS AND COAL
MINES
Abstract
A method of reducing greenhouse gases while simultaneously
generating carbon credits includes mitigating greenhouse gases at
unregulated landfill sites or mitigating greenhouse gases at
regulated landfill sites in excess of the required mitigation
activities, obtaining carbon credits in an amount created by the
mitigation efforts and selling or using the carbon credits in an
open market to, for example, offset the costs of the mitigation
efforts or to fund or support other greenhouse gas emission
activities.
Inventors: |
Duesel, JR.; Bernard F.;
(Goshen, NY) ; Rutsch; Michael J.; (Tulsa, OK)
; Clerkin; Craig; (Stoughton, WI) |
Assignee: |
HEARTLAND TECHNOLOGY PARTNERS
LLC
Kirkwood
MO
|
Family ID: |
44121845 |
Appl. No.: |
13/072264 |
Filed: |
March 25, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12043786 |
Mar 6, 2008 |
|
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13072264 |
|
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60893345 |
Mar 6, 2007 |
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Current U.S.
Class: |
705/500 |
Current CPC
Class: |
Y02W 30/30 20150501;
G06Q 99/00 20130101; Y02W 10/20 20150501; C02F 11/04 20130101; B09B
1/00 20130101; Y02W 10/23 20150501; B01D 53/62 20130101; B01D
2258/0291 20130101; Y02W 30/35 20150501; B01D 2251/304
20130101 |
Class at
Publication: |
705/500 |
International
Class: |
G06Q 90/00 20060101
G06Q090/00 |
Claims
1. A method of reducing greenhouse emissions at an abandoned coal
mine, comprising: collecting a first greenhouse gas released from
exposed coal seams in the abandoned coal mine prior to the first
greenhouse gas entering the atmosphere outside of the abandoned
coal mine; converting at least some of the first greenhouse gas
into a second, less potent greenhouse gas; and applying for a first
set of greenhouse gas emission reduction credits for converting the
at least some of the First greenhouse gas into the second, less
potent greenhouse gas, wherein the greenhouse gas emission
reduction credits are tradable on a financial exchange.
2. The method of claim 1, wherein converting the at least some of
the first greenhouse gas into the second, less potent greenhouse
gas includes using the first greenhouse gas as a fuel source in an
additional process or processes.
3. The method of claim 2, further including applying for a second
set of greenhouse gas emission reduction credits for reducing the
use of fossil fuels in the additional process or processes as a
result of using the first greenhouse gas as the fuel source in the
additional process.
4. A method of reducing greenhouse gas emissions at a landfill,
comprising: analyzing gas mitigation measures already in place at
the landfill; analyzing by-product mitigation measures already in
place at the landfill; measuring the amount of fossil fuel used to
mitigate the by-products in the by-product mitigation measures;
calculating a greenhouse gas emission reduction credit potential
for the landfill by determining the amount of the first greenhouse
gas needed to power the by-product mitigation measures; and
applying for a first set of greenhouse gas emission reduction
credits based on the amount of fossil fuel saved by using the first
greenhouse gas as a fuel for the by-product mitigation
measures.
5. The method of claim 4, wherein the by-product mitigation
measures include landfill leachate evaporation.
6. The method of claim 4, further comprising accounting for the
monetary value of the greenhouse gas emission reduction credits in
an overall budgeting process when calculating a cost of installing
greenhouse gas emission reduction equipment.
7. The method of claim 4, wherein the first greenhouse gas is
methane.
8. The method of claim 4, further comprising converting the first
greenhouse gas into a second, less potent greenhouse gas when
powering the by-product mitigation measures.
9. The method of claim 8, wherein converting the first greenhouse
gas into the second, less potent greenhouse gas includes burning
the first greenhouse gas.
10. The method of claim 9, further comprising diverting at least
some heat generated by burning the first greenhouse gas into the
by-product mitigation measures to at least partially evaporate
landfill leachate.
11. The method of claim 10, wherein the landfill leachate is at
least partially evaporated in a submerged combustion gas
evaporator.
12. The method of claim 10, wherein the landfill leachate is at
least partially evaporated in a concentrator having a narrowed
section and a demister.
13. The method of claim 8, further comprising applying for a second
set of greenhouse gas reduction credits based on converting the
first greenhouse gas into a second, less potent greenhouse gas.
14. The method of claim 8, wherein the first greenhouse gas is
burned in an electrical power generator.
15. The method of claim 14, further comprising diverting at least
some exhaust from the electrical power generator into at least one
of the by-product mitigation measures.
16. The method of claim 15, further comprising applying for a
second set of greenhouse gas emission reduction credits based upon
using the first greenhouse gas as a fuel for creating electricity
in the electrical power generator instead of using a fossil fuel in
the electrical power generator.
17. A method of reducing greenhouse gas at a landfill, comprising:
collecting a first landfill gas, which is a greenhouse gas, in a
landfill gas collection system; burning the collected first
landfill gas, thereby forming an exhaust gas including a second,
less potent greenhouse gas; collecting landfill leachate in a
landfill leachate collection system; transporting the leachate to a
landfill leachate evaporation or concentration device; diverting a
first portion of the exhaust gas to the landfill leachate
evaporation or concentration device, wherein latent heat in the
exhaust gas at least partially evaporates the landfill leachate;
and diverting a second portion of the exhaust gas to an industrial
operation and using latent heat in the second portion of the
exhaust gas as an energy source in the industrial operation.
18. The method of claim 17, wherein the landfill leachate
evaporation or concentration device is a submerged gas
evaporator.
19. The method of claim 17, wherein the landfill gas is burned in
an electric power generator, and further comprising applying for a
fourth set of greenhouse gas emission reduction credits based on
using the landfill gas as a fuel source for the power generator
instead of using a fossil fuel as a fuel source for the power
generator.
20. The method of claim 17, wherein the landfill gas is methane and
the less potent greenhouse gas is carbon dioxide.
21. The method of claim 17, further comprising applying for a first
set of greenhouse gas emission reduction credits based on
transforming the landfill gas into a less potent greenhouse
gas.
22. The method of claim 21, further comprising applying for a
second set of greenhouse gas emission reduction credits based on
using landfill gas as fuel in the landfill leachate evaporation or
concentration device instead of using a fossil fuel in the landfill
leachate evaporation or concentration device.
23. The method of claim 22, further comprising applying for a third
set of greenhouse gas emission reduction credits based on using
latent heat from the second portion of the exhaust gas as an energy
source in the industrial operation instead of using energy from
fossil fuel as an energy source in the industrial operation.
Description
RELATED APPLICATIONS
[0001] This patent application is a continuation of U.S. patent
application Ser. No. 12/043,786, filed on Mar. 6, 2008, which is a
non-provisional application claiming priority benefit of U.S.
Provisional Patent Application No. 60/893,345, filed on Mar. 6,
2007. The entire disclosures of U.S. patent application Ser. Nos.
12/043,786 and 60/893,345 are hereby expressly incorporated by
reference herein.
FIELD OF THE DISCLOSURE
[0002] This disclosure relates generally to a method of reducing
the emissions of greenhouse gases in landfills and coal mines, and
more specifically to a method of generating carbon credits while
reducing greenhouse gases at various sites, such as landfills and
coal mines.
BACKGROUND
[0003] Generally speaking, "global warming" refers to the observed
increase in the average temperature of the Earth's atmosphere and
oceans in recent decades and the projected continuation of this
increase in temperatures. Models referenced by the
Intergovernmental Panel on Climate Change (IPCC) predict that
global temperatures are likely to increase by 1.1.degree. to
6.4.degree. C. (2.0.degree. to 11.5.degree. F.) between 1990 and
2100. The uncertainty in this range results from two factors,
namely, differing future greenhouse gas (GHG) emission scenarios,
and uncertainties regarding climate sensitivity.
[0004] Global average near-surface atmospheric temperature rose
0.74.+-.0.18 degrees Celsius (1.3.+-.0.32 degrees Fahrenheit) in
the last century. The prevailing scientific opinion on climate
change is that most of the observed increase in globally averaged
temperatures since the mid-20th century is very likely to be due to
the observed increase in anthropogenic greenhouse gas
concentrations, leading to a warming of the Earth's surface and
lower atmosphere by increasing the greenhouse effect. Greenhouse
gases are released by activities such as the burning of fossil
fuels, land clearing, agriculture, and the natural decay of trash
in landfills.
[0005] Greenhouse gases are components of the atmosphere that
contribute to the greenhouse effect. Some greenhouse gases occur
naturally in the atmosphere, while others result from human
activities. Naturally occurring greenhouse gases include water
vapor, carbon dioxide, methane, nitrous oxide, and ozone. Certain
human activities, however, add to the levels of most of these
naturally occurring gases. For example, decomposition of trash
placed into a landfill is an anaerobic process that produces
methane gas which, in turn, leaves the landfill as landfill gas.
The amount of methane gas created from decomposition depends on a
number of factors, but is generally proportional to the composition
and amount of trash placed within the landfill. Thus, each ton of
trash at a given composition that is placed into a landfill creates
a predictable amount of methane gas. However, owners of landfills
will often not take action to mitigate the greenhouse gases (such
as methane gas) produced in a landfill because the costs of such
mitigation are too high, and in many cases such mitigation actions
are not required by the governmental regulating bodies which
regulate landfill operations.
[0006] However, there is currently a global focus on reducing GHG
emissions. In fact, both international and national initiatives are
currently in force and others are pending or under consideration.
One example of a global effort to mitigate the effects of
greenhouse gases on the global climate is the Kyoto Protocol to the
United Nations Framework Convention on Climate Change, which is an
amendment to the international treaty on climate change, assigning
mandatory targets (GHG targets) for the reduction of greenhouse gas
emissions to signatory nations. The Kyoto Protocol includes
flexible mechanisms which allow some economies to meet their GHG
targets by purchasing GHG emission reductions (often called "carbon
credits") from elsewhere. These carbon credits can be bought or
otherwise obtained either via financial exchanges (such as the new
EU Emissions Trading Scheme) or from projects which reduce
emissions in other economies.
[0007] Although several countries (most notably the United States)
have not yet and may never ratify the Kyoto Protocol, there are
also private initiatives in, for example, the United States where
units of the government and private companies can voluntarily agree
to reduce their GHG emissions. While joining the program is
voluntary, members of this program have legally enforceable
requirements for GHG reductions. Currently, this initiative is
administered by the Chicago Climate Exchange (CCX). The CCX also
hosts a trading exchange which facilitates the sale of carbon
credits by members who do not release the amount of allowed GHG,
and which facilitates the purchase of emission reductions (carbon
credits) by members who are not able to achieve their required GHG
reductions through their own operations. GHG reduction projects
anywhere in the world are eligible for trading carbon credits on
the CCX.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Objects, features, and advantages of the present invention
will become apparent upon reading the following description in
conjunction with the drawing figures, in which:
[0009] FIG. 1. is a schematic representation of methods of
generating greenhouse gas (GHG) emission reduction credits.
[0010] FIG. 2 is a schematic representation of different ways of
reducing methane emissions to generate GHG emission reduction
credits.
[0011] FIG. 3 is a schematic representation of a low cost
concentrator used to process wastewater.
[0012] FIG. 4 is a schematic representation of a second low cost
concentrator used to process wastewater.
[0013] FIG. 5 is an illustration of a method of reducing GHG
emissions and generating carbon credits at an unregulated
landfill.
DETAILED DESCRIPTION
[0014] A method of reducing greenhouse gas emissions by creating
and accounting for greenhouse gas emission reduction credits is
described herein. Although greenhouse gas emission reduction
credits are referred to hereinafter as "carbon credits," greenhouse
(as emission reductions do not have to be related to the reduction
of "carbon" emissions per se, but can be related to the reduction
of other greenhouse gas emissions. The method includes performing
an initial site evaluation which may include, in part, measuring
the amount of greenhouse gases emitted from the site and an
analysis of mitigation measures already employed at the site,
including mitigation of other undesirable by-products, such as
landfill leachate or other wastewater. Often these other mitigation
measures, such as treating landfill leachate, consume fossil fuels
as an energy source to treat the undesirable by products. After the
initial site evaluation, the carbon credit potential of the site
may be calculated by determining how much methane or other
greenhouse gas (GHG) can be converted or used to power mitigation
processes already in place, if any. Once the carbon credit
potential is calculated, an application may be submitted to the
Chicago Climate Exchange (CCX) (or other carbon credit market
entity) describing the proposed process and potential reduction of
GHG emissions from the site.
[0015] At some point, such as when the CCX (or other carbon market
entity) approves the application, an economic analysis of the
project is conducted in which the carbon credits are accounted for
in the overall budgeting process. Often, these carbon credits may
turn an unprofitable site into a profitable site while improving
the environment by at least partially offsetting the costs of
installing GHG emission reduction equipment. Once it is determined
that GHG emission reduction at a site is economically feasible
(including accounting for the carbon credits), appropriate
equipment is installed at a site and is operated to reduce the
overall emission of greenhouse gases according to the application,
thereby generating carbon credits, which may then be issued and
traded (or sold) on an exchange such as the CCX.
[0016] Turning now to FIG. 1, at least four methods of generating
carbon credits 10 are available under the Kyoto Protocol or the
CCX. A first method 20, which is probably the most effective way to
reduce GHG emissions and thereby produce carbon credits, is to
destroy methane or avoid methane generation. Methane is generally
destroyed by burning the methane. Carbon credits for methane
destruction or avoidance are generally available for any site
(e.g., landfill) where there is no current regulatory requirement
to destroy methane or avoid methane generation. Carbon credits are
also available for regulated sites that implement methane
destruction or avoidance procedures which exceed regulatory
requirements. Methane generation is generally avoided by reducing
the amount of trash available for decomposition in a landfill.
[0017] A second method 30 of generating carbon credits is to use
renewable fuel sources instead of fossil fuels for some process. In
particular, carbon credits are available when a process that
consumes fossil fuel is switched to consume a renewable fuel, such
as landfill gas. One likely technology available to use landfill
gas as a fuel source includes the implementation of submerged gas
evaporators/processors (SGE/SGP) as shown in U.S. Pat. No.
5,342,482 and U.S. Patent Publication No. 2004/0040671, both of
which are hereby incorporated by reference. Commercial examples of
such SGEs are Liquid Solutions' E-VAP.TM. and RE-VAP.TM.
technology. Other technologies which may be available to use
landfill gas or other renewable fuel sources include power
generation systems and/or waste heat recovery systems used in, for
example, industrial/commercial facilities. Those in the carbon
reduction industry refer to these carbon credits as "fuel switch"
credits.
[0018] A third method 40 of generating carbon credits is to improve
current technology to reduce the GHG outputs of such technology,
such as developing cleaner burning power plants (i.e., those which
reduce GHG emissions) and more efficient automobile engines. Carbon
credits are also available to those who reduce emission when
technology improvements decrease the amount of energy used to
perform the same function (i.e., when implementing a more efficient
process). Carbon credits generated by such activities and issued by
a carbon credit trading authority (e.g., CCX) may be used to at
least partially offset the research and development costs of
improving the current technology and the cost of implementing the
technology.
[0019] A fourth method 50 of generating carbon credits is to
sequester greenhouse gas emissions before they are released to
atmosphere. The sequestering of greenhouse gas emissions may be
accomplished by using submerged gas reactors that process carbon
dioxide in an exhaust gas by reacting the carbon dioxide with an
alkali to form a carbonate salt thereby removing carbon dioxide
from the exhaust gas and sequestering the carbon dioxide in a
different molecular form (e.g., sodium carbonate) for re-use or
disposal. An example of a commercially available submerged gas
reactor is Liquid Solutions' RE-VAP system.
[0020] FIG. 2 illustrates a number of different processes or areas
where methane destruction or avoidance 20 is effective in reducing
GHG emissions and thereby generating carbon credits. There are at
least two methods of reducing methane generated by landfills, which
are significant generators of methane. In particular, methane
production can be reduced by (1) reducing the amount of trash put
into a landfill, thereby reducing the amount of methane produced in
the landfill, and (2) processing the methane to produce a less
potent greenhouse gas.
[0021] In the first case, when trash is placed into a landfill 60,
the decomposition process, which is an anaerobic process, produces
methane gas that leaves the landfill 60 as landfill gas. The amount
of methane gas created from the decomposition process depends on a
number of factors, but is generally proportional to amount of trash
placed into the landfill. Thus, each ton of trash deposited into a
landfill produces a predictable amount of methane gas. Conversely,
each ton of trash that would have otherwise been placed into a
landfill, but is instead used for some other purpose, reduces the
amount of methane gas generated by an amount generally proportional
to the amount of trash not placed into the landfill 60 as is
illustrated by the block 52 of FIG. 2. There are some technologies
that can be used to reduce the amount of trash that needs to be
placed into a landfill 60, including converting the trash to fuel,
composting the trash, and/or recycling the trash. Thus, reducing
the amount of trash put into a landfill 60 is a way of generating
carbon credits through methane avoidance.
[0022] In one example of diverting biodegradable wastes from
landfills, the biodegradable waste may be converted into refuse
derived fuel (RDF). RDF diverts biodegradable material from
landfills thereby avoiding methane production within the landfill
while providing a renewable fuel that is easy to transport and may
be used as a substitute for fossil fuels. Trash can be converted to
fuel by preparing the trash in a shredder/compactor and compressing
the trash to produce compact RDF that may be used as an energy
source in place of fossil fuel. For example, the shredder/compactor
may produce RDF in a variety of forms, pellets, briquettes, fuel
rods, etc.
[0023] In another example of diverting biodegradable wastes from
landfills, digesters may be used to treat solid and liquid organic
wastes such as manure, liquid and food wastes (e.g., animal and
vegetable fats), etc. produced in agricultural operations to reduce
the natural uncontrolled release of methane to atmosphere wherever
the solid and liquid organic wastes decompose under anaerobic
conditions such as within soil or piles. Methane produced in the
controlled anaerobic environment within digesters is captured and
may be applied to a wide range of processes. Wherever applied, if
the use of energy from the methane generated in a digester
displaces the use of fossil fuels, carbon credits may be
generated.
[0024] Another way to reduce the methane gas emitted from landfills
is to process the methane gas 54 to convert the methane gas into a
less potent GHG. For example, simply burning the methane in a flare
reduces the greenhouse effect because the products of the
combustion CO.sub.2 and H.sub.2O have a less significant greenhouse
effect than the methane gas itself. Methane gas is a substantially
more potent GHG emission than CO.sub.2 or H.sub.2O and converting
methane gas to other products, such as CO.sub.2 and H.sub.2O
reduces the greenhouse effect.
[0025] Similarly, it is possible to reduce GHG emissions by
processing methane gas produced in abandoned coal mines 70. In
particular, methane gas, which is found in many coal seams, is
released to the atmosphere when the coal seam is disturbed, both
during mining operations and after mining operations have ceased.
In some cases, the methane gas can be economically recovered. In
other cases, destruction of the methane may be required by
regulation. However, there are many locations where destruction of
the methane gas is not required nor currently financially
viable.
[0026] Another method of reducing GHG emissions is to implement a
product recovery process 80, such as the recovery of methanol.
Methanol, which is an industrial chemical used in many
applications, is commonly manufactured from natural gas. Often,
methanol is used for cleaning or other processes where the methanol
is not consumed. In many cases, the spent methanol is disposed of
in, for example an incinerator or other waste treatment process.
However, it is possible in many cases to collect and recover spent
methanol and then to convert the spent methanol back to a
commercial grade methanol. Because the most commonly used process
for manufacturing methanol consumes large quantities of natural
gas, each gallon of recovered or converted methanol reduces the
amount of natural gas consumed. Further, if spent methanol is
recovered in a process that includes a distillation stage employing
waste heat or heat energy produced from a renewable energy source
such as the methane found in landfill gas, additional reductions in
the use of natural gas and/or other fossil fuels may be realized.
The substitution of energy derived from waste heat or a renewable
fuel source is an avoidance of the additional greenhouse gas
emissions (carbon credit) that would have resulted from the direct
use of fossil fuel in the distillation process.
[0027] Current U.S. regulations force landfills over a certain size
to collect and treat gases generated by the landfill. However, this
type of regulation leaves a large number of smaller landfills
unregulated as to collection and treatment of landfill gas. Often,
owners of non-regulated sites, such as non-regulated landfills,
take minimal or no action to mitigate greenhouse gas emissions
because the costs of mitigation yield minimal or negative return on
investment. Moreover, in the case of many regulated landfills, only
the minimum required landfill gas control treatment, such as
burning the landfill gas in a flare is implemented.
[0028] As will be understood, using various techniques with various
underlying technologies, non-economically viable sites such as
landfills, coal mines, etc., may be modified to reduce the
emissions of greenhouse gases in an economically viable manner
based on the incorporation, creation, accounting for and selling of
carbon credits. In other words, the value of the carbon credits at
least partially offsets the costs of installing and maintaining
greenhouse gas emission reducing equipment. Often, the carbon
credits alone have enough value to make collection and disposal of
greenhouse gases at landfills and other sites profitable.
Furthermore, even regulated sites can benefit from these techniques
as collection and conversion of greenhouse gases above and beyond
the regulated requirements may be accomplished to generate carbon
credits.
[0029] One method of reducing greenhouse gases and thereby
generating carbon credits is to beneficially utilize landfill gas
to process landfill leachate in, for example, a submerged
combustion gas evaporator (SGE), such as that illustrated in U.S.
Pat. No. 5,342,482 and U.S. Patent Publication No. 2004/0040671
(FIG. 5). Because combustion gas evaporators evaporate liquids by
injecting hot combustion gas into a liquid, switching the
combustion gas in such an evaporator from a fossil fuel to a
renewable gas (e.g., substituting methane generated in landfills or
digesters for natural gas) reduces greenhouse gas emissions and
thereby provides a basis for generating carbon credits. These
carbon credits currently trade for $0.5 to $2 per ton on the CCX,
although the value of the carbon credits will fluctuate in
accordance with supply and demand on the exchange. A typical
submerged combustion gas evaporator treating 10,000 gallons per day
of leachate that employs a landfill gas flare to treat exhaust
vapor reduces greenhouse gas emissions by about 170 metric tonnes
per day of carbon dioxide equivalent (CO.sub.2e), thereby creating
a number of carbon credits and thus providing a significant
economic incentive in producing the credits. Often, the creation,
accounting for, and selling of carbon credits are enough to turn a
non-profitable landfill gas to energy project into a profitable
one.
[0030] Another method of generating carbon credits while disposing
of landfill gas is evaporating waste water (such as landfill
leachate) with relatively compact, inexpensive gas liquid
contacting devices that run on renewable fuels, such as landfill
gas. Two such low cost concentrators are shown in FIGS. 3 and 4.
Each concentrator includes a gas inlet 220, 320, a gas exit 222,
322 and a flow corridor 224, 324 connecting the gas inlet 220, 320
and a gas exit 222, 322. The flow corridor 224, 324 includes a
narrowed portion 226, 326 that accelerates the gas through the flow
corridor 224, 324. A liquid inlet 230, 330 injects liquid into the
gas stream at a point prior to the narrowed portion 226, 326. The
gas liquid combination is thoroughly mixed within the flow corridor
224, 324 and a portion of the liquid is evaporated at the adiabatic
system temperature. A demister 234 (or cyclonic mixing chamber 352)
downstream of the narrowed portion 226, 326 removes entrained
liquid droplets from the gas stream and re-circulates the removed
liquid to the liquid inlet 230, 330 through a re-circulating
circuit 242, 342 driven by pumps 240, 340. Fresh liquid is
introduced into the re-circulating circuit 242, 342 via an inlet
244, 344 at a rate sufficient to offset the amount of liquid
evaporated in the flow corridor 224, 234. Additionally,
concentrated fluid is output from the re-circulating circuit 242,
342, via outlets 246, 346. Induction fans 250, 350 pull gas and
entrained liquid through the demister 234 and the cyclonic mixing
chamber 352 to the gas exits 222, 322. In FIG. 4, the gas is
provided to the exit 322 via a hollow cylinder 356. These low cost
concentrators are generally compact and transportable because many
of the components may be manufactured from lightweight, inexpensive
materials such as, plastic or fiberglass. Thus, these concentrators
may be moved from site to site as needs dictate.
[0031] Using landfill gas to produce power (generally electricity)
is another method of reducing greenhouse gas emissions and thereby
generating carbon credits while disposing of landfill gas, because
the power generating equipment is not using fossil fuels as it
normally would be. Such power generation equipment can be used in
conjunction with the above mentioned submerged combustion gas
evaporators (i.e., the combustion gas used in the SGE is taken
directly from the power generating equipment) and low cost
concentrators. In this manner, depending on the regulatory status
of the landfill, the carbon credits generated may be additive: once
for the destruction of the methane gas and again for the generation
of power from a renewable energy source. Furthermore, the power
generated may be sold on the open market for an additional
profit.
[0032] Moreover, waste heat generated by such power generating
equipment may be recovered and reused by a heat recovery system,
thereby further reducing greenhouse gas emissions and creating
additional carbon credits. Two example waste heat recovery systems
are shown in U.S. patent application Ser. Nos. 11/114,822 and
11/114,493, both of which are hereby incorporated by reference. In
this case, the recovered waste heat may be transported to a nearby
industry for use (FIG. 5). Again, such a method generates carbon
credits because the waste heat, generated by a renewable fuel, is
used in place of a traditional fossil fuel heat source.
[0033] FIG. 5 depicts an example of a method of reducing greenhouse
gases and generating carbon credits by 1) destroying more potent
GHG: 2) converting conventional processes to renewable fuel
sources; and 3) using waste heat in industrial operations in place
of heat generated by burning fossil fuels. The value of the carbon
credits generated by this example method may be used to at least
partially offset the costs of installing and maintaining the
greenhouse gas emission reducing equipment. A typical small,
unregulated landfill 100 is fitted with a gas collection system 110
and a liquid collection system 120. Landfill gas collected by the
gas collection system 110 is burned in a combustion process 130
that may be a flare or other combustion process such as an engine,
thus reducing the greenhouse effects of the methane by converting
the methane into CO.sub.2 and H.sub.2O and further generating
carbon credits in the process. Landfill leachate collected by the
liquid collection system 120 is transported to a Submerged Gas
Evaporator (SGE) or a low cost concentrator 140. The SGE or low
cost concentrator 140 uses the exhaust gas from the combustion
process 130 to process and evaporate the leachate delivered by the
liquid collection system 120. Thus, the SGE or low cost
concentrator 140 generates carbon credits by processing the
leachate with a renewable energy source (landfill gas) instead of
using a combusted fossil fuel. Further, if caustic is added to the
leachate, CO.sub.2 from the exhaust gas may be sequestered as
sodium carbonate, thus further reducing greenhouse gas emissions
and generating further carbon credits. Over time, the carbon
credits generated by the combustion process 130 and the SGE or low
cost concentrator 140 may meet or exceed the costs of installing
such a system. Thus, the generation of the carbon credits may
improve the environment by making the installation of greenhouse
gas reducing systems and/or leachate treatment systems economically
feasible.
[0034] Additionally, waste heat 150 from the combustion process 130
may be captured and used in an industrial process in a nearby
industry 160. Using the waste heat instead of heat from burning a
fossil fuel generates carbon credits as discussed above. Thus, the
exemplary method shown in FIG. 5 generates carbon credits in at
least four different ways. First, GHG (landfill gas, i.e., methane)
is destroyed generating carbon credits. Second, landfill gas (a
renewable energy source) is used to evaporate and treat the
landfill leachate instead of burning fossil fuel to evaporate and
treat the leachate. Third, CO.sub.2 from exhaust gas may be
sequestered by chemical conversion, thus reducing the amount of
CO.sub.2 released to the atmosphere. Fourth, waste heat from a
combustion device is used in an industrial process that normally
would use heat generated by burning a fossil fuel.
[0035] Thus, one general method of reducing greenhouse gas
emissions at, for example, a landfill, wastewater treatment plant,
coal mine or other site that produces greenhouse gases, including
for example methane gas, includes installing and/or using gas
collection technology at the site to collect the gas, and
thereafter implementing gas processing technology to convert the
collected gas to other forms having reduced greenhouse gas volume
or potency, all at a level greater than that required by the
relevant regulations effecting the site. The collected gas may be
processed in a combustion process, such as in a flare or other
burner to convert the gas to other materials that are less potent
greenhouse gases, and/or may be used as a fuel source to power
other processes which might otherwise use fossil fuels, which
thereby further reduces the production of greenhouse gases. Still
further, the waste heat from the burning of the collected gas may
be used in other processes to further reduce the amount of fossil
fuels used in those other processes, thereby further reducing the
emission of greenhouse gases that would otherwise be created by the
use of fossil fuels or other non-renewable fuels.
[0036] As an integral part of this process, an estimate of the
amount of reduction of the greenhouse gas emissions that will be
obtained as a result of the installation and/or use of the gas
collection and processing technology may be determined, and this
estimate may be used to apply for approval or other authorization
from an appropriate carbon credit trading authority for the
generation of carbon credits. After the carbon credit creation
process is approved and implemented at the site, the amount of
greenhouse gas reduction actually accomplished at the site may be
determined based on, for example, measurements of the amount of gas
collected at the site, the amount and type of gas processed or
converted to other products, the amount of fossil fuels which were
not used due to the use of the collected gas as a power or energy
source instead, etc. These measurements, which may be based on gas
volume measurements, gas potency or composition measurements,
energy measurements, etc., may then be used to actually obtain
issuance of the carbon credits via the credit trading authority
based on the approved process. Thereafter, the obtained carbon
credits may be sold or traded via that or any appropriate trading
or exchange authority, and thereby used to finance the installation
and running of the gas emission reduction technology or for any
other purpose such as to offset other carbon or greenhouse gas
generating processes.
[0037] According to another method of reducing greenhouse gas
emissions, waste reduction technology, such as technology that
reduces the amount of waste that needs to be placed into a landfill
site, may be installed or used to reduce greenhouse gas emissions.
This technology may, for example, convert the waste that would
otherwise be placed into the landfill into a usable form, such as a
fuel source. In one example, appropriate types of waste may be
highly compacted and later burned as fuel. In another example,
certain types of the waste, such as plastics, paper products, etc.,
may be collected and recycled in known recycling processes to
reduce the waste placed into the landfill site. The amount of
converted waste may then be used to determine a number of carbon
credits based on a projection of the reduction of methane gas that
would otherwise result from the decomposition of that waste in the
landfill site over time.
[0038] Still further, if the waste is converted to a fuel source,
the fuel source may be used in one or more processes instead of
fossil fuels to reduce the amount of fossil fuels used to power
these other processes, thereby creating the basis for additional
carbon credits. Also, heat or other waste energy from the use of
the waste-based fuel source may be used as energy in still other
processes, thereby further reducing the amount of fossil fuels
needed to implement those other processes and thus further reducing
greenhouse gas emissions.
[0039] Again, as an integral part of this process, an estimate of
the amount of reduction of the greenhouse gas emissions that are
obtained as a result of the installation and/or use of the waste
reduction technology (including the use of renewable fuel created
as a by-product of this waste reduction technology) may be
determined, and this estimate may be used to apply for approval or
other authorization from an appropriate carbon credit trading
authority for the generation of carbon credits. After the carbon
credit creation process is approved and implemented at the site,
the amount of greenhouse gas reduction actually accomplished at the
site may be determined based on, for example, measurements of the
amount of processed or converted waste, the amount and types of
fuel created as a result of the waste conversion process, the
amount of fossil fuels which were not used due to the use of the
waste-based fuel as a power or energy source, etc. These
measurements, which may be based on waste reduction volume
measurements, waste-based fuel production measurements, waste-based
fuel composition measurements, measurements of the energy created
from the waste-based fuel, etc., may then be used to obtain carbon
credits via the credit trading authority based on the approved
process. Thereafter, the obtained carbon credits may be sold or
traded via that or any appropriate trading or exchange authority,
and thereby used to finance the installation and running of the
waste reduction technology or for any other purpose such as to
offset other carbon or greenhouse gas generating processes.
[0040] Additionally, this method of reducing greenhouse gas
emissions provides an opportunity to tailor site specific GHG
reducing technology to the particular characteristics of an
existing landfill site (e.g., size, condition, existing operations,
infrastructure, etc.) in order to maximize the reduction of GHG and
thus maximize the production of carbon credits.
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