Problem Statement TheU.S.DepartmentofDefense(DoD)occupiesover620,000buildingsatover400instal-lationsintheU.S.spendingover$2.5billiononenergyconsumptionannually.Reductionsinenergyconsumptionfromthesefacilities,andutilizationofrenewableenergysourceshavebecomeaprimarygoaloftheDoDto:• Reduceemissionsandenvironmentalimpactsrelatedtopowerproductionand consumptioninresponsetoairpollutionandclimatechangeissues.• Reducecostsassociatedwithenergyconsumption,resultinginadditional resourcesaimedattheDoDprimarymission.• Improveenergysecurity,flexibility,andindependence.Currently, the Air Force alone operates 563 landfills at U.S. installations. Landfills produce waste gas streams containing methane that is vented, flared, or otherwise destroyed. Aside from wasting a potentially useful renewable fuel source, the methane in landfill gas represents a significant global warming potential. Methane has been identified as a greenhouse gas whichisharmfultotheEarth’satmosphereandisconsideredtobeover20timesworsethanCO2intermsofglobalwarmingpotential.CurrentApproachesandDrawbacks:•Venting • Methane (potent GHG) emissions •Regulatorylimits • Site utilization (brownfields) requires remediation•Flaring • Emissions (CO2, NOx, PM, etc.) and associated regulatory burden •Energyconsumption(supplementalfuel) •Capitalcostandmaintenance•Onsitepowergeneration •Feasibleoption •Currenttechnologiesonlyfeasibleduringpeakmethanegeneration
Potential Solution • Utilize a waste fuel stream (LFG) to generate on site electric power• Eliminates venting or flaring of LFG•Offsetelectricitypurchasesanddependencyoncommercialpower•Reduceemissionsandenvironmentalimpactsrelatedtopowerproduction and LFG emissions•Reducecostsassociatedwithenergyconsumption• Improve energy security, flexibility, and independence
ObjectiveTheobjectiveofthisproposedprojectistodemonstrateandverifytheeconomicandenviron-mental utility of an advanced waste-to-energy technology at DoD landfills. A unique microtur-bine technology provided by Flex Energy is capable of utilizing ultra-low-BTU landfill or other waste gases as fuel to provide efficient on-site power production. In addition to landfills, this systemhaspotentialapplicationonavarietyofDoDsites,includingwastewatertreatment,VOCremediationsystems,andwellothertypicalfossilfuelapplications.Thisdemowillbecompleted jointly with the EPA ETV Green House Technology Center.
Technology DescriptionMicroturbines: •Compact,lowmaintenance,modular,lowemissions •Varietyoffuels,proveninterconnection • Challenge: High fuel pressure or high maint. compressorFlex-Microturbine®Capabilities: • Unique thermal oxidizer allows the Flex to run on gas that is as low as 15 BTU per cubic footatatmosphericpressure • Adapted to varying fuel energy content and quality • Maximum gross electric power output of 200kW •Integrateddesignforsimplegridinterconnection •integrateallprotectiverelayfunctions •remoteoperationandmonitoringFlex-Microturbine®Design: • Modified Solar Spartan microturbine • fuel system modifications to blend the fuel with air, reducing the BTU content below combustiblelimits •nofuelcompressor–air/fuelmixthroughturbineintakecompressor •useofaproprietarythermaloxidizerinsteadoftraditionalcombustion •FlexibleoperationallowsforuseoffuelwithvaryingBTUcontent • gas clean-up system not necessary when operating on landfill gas“Flex”Advantagesovertraditionalmicroturbines: • A single power plant can handle a wide range of fuels (1.5% CH4 to 100% CH4). • Operation on ultra-low BTU LFG, making it usable throughout a landfill’s active and post-closurelife. •Eliminationoftraditionalfuelcompressor • Low NOx emissions (as low as 0.01 lb/MWh vs. the 2007 California certification level of 0.07 lb/MWh). • The oxidizer will oxidize H2S, eliminating the need for a H2S clean-up system • Gas is utilized at atmospheric pressure.
Fig1:The“Flex”runningon15to42BtugasatanoilfieldnearSantaBarbara
x
x
x
xxx
NOx (ppb)
NO (ppb)
NO2 (ppb)
CO (ppm)
CO2 (%)
x
30
25
20
15
10
5
0
-5
-10
0 5 10 15 20 25
Emis
sion
s
Power kW Note: Ambient NOx was 40 ppb
Flex-Microturbine® Emissions Testing
Fig2:EmissionData
Economic Analysis Assumptions:•Substantialcostreductionsasvolumesincrease.•Installationcostscanbesubstantiallyreduced•Operatingcostswillreduce• Gas cleanup costs will increase•Fuelcostsareassumedtobezero.• The value of electric power is assumed to be $.10/kWh and stable. • No value is placed on carbon or NOx credits, waste heat recovery, offset of flare fuel, or other potential benefits.
Environmental Benefits of TechnologyIn addition to the potential economic benefits presented by the Flex, there are potential envi-ronmental benefits as well. •electricitygeneratedbytheFlexoffsetselectricitysuppliedbytheutilitygrid•reductioninelectricitydemandfromthegrid,offsetbyon-sitepowerproduction• emission reductions of NOX , PM, and other emissions•25Flexmicroturbineswouldoffsetemissionsassociatedwithpowergenerationof approximately 4.7 tpy of NOx emissions• By venting LFG at the rate of 700 scfm at Fort Benning, the carbon equivalent emission rate would be approximately 12,246 tons of carbon equivalents per year. Oxidizing this methanetoCO2throughuseof25Flexmicroturbinesystemswouldresultinanestimatedannual carbon equivalent emission rate of 1464 tpy, equating to an overall emission reduction on the order of 10,782 tons carbon equivalent.
About Southern Research & the Greenhouse Gas Technology Center
Southern Research Institute operates the Greenhouse Gas Technology Cen-ter (GHG Center)
underacooperativeagreementwiththeUSEnvironmentalProtectionAgency Office of Research and Development’s Environmental Technol-ogy Verification (ETV) Program. The GHG Center’s mission is to further environmentalprotectionbysubstantiallyacceleratingtheacceptance
and use of improved and innovative environmental technologies. With performance data developed under this program, technology buyers, finan-
ciers, and permitters in the United States and abroad are better equipped to makeinformeddecisionsregardingenvironmentaltechnologypurchaseanduse.Ourclientsrangefromtechnologydevelopersthatneedanindependentpartytoprovidereliabletestdatatocompaniesandgovernmentagenciesthatneedto“benchmark”multipletechnologiestosubstantiateclaimsandreal-worldimplications.
Technologies are evaluated using a formal verification process that is guided by stakehold-ers and peer reviewers. The GHG Center uses recognized standards, protocols and testing organizations to complete the verifications. All test plans, data, analysis and reports are peer reviewed, and undergo rigorous quality assurance reviews under the GHG Center’s and the EPA’s ETV Program Quality Management Programs.
Fig1:LandfillmethaneventFig2:Landfillflaring
Fig3:LandfillpowergenerationCost Benefits of Technology
Table1.1:30kwFlex-MicroturbineataDoDLandfill-Cost/BenefitAnalysis
Year CapitalCosts($/KW) Fuel,O&MCosts($/kW-Yr) Revenues Benefit Payback ($/kW-Yr) ($/kW-Yr) (Years)
Total Gas Total Cost Cost to Cap Operation Maint. Cleanup O&M Power Net Payback ofUnit Install Costs Cost Cost Cost Cost Revenue Period
2008 2,000 1,000 3,000 175 131 53 359 876 517 5.82012 1,500 750 2,250 150 100 60 310 876 566 4.02016 1,000 500 1,500 150 100 70 320 876 556 2.7
Performance of a Microturbine Power GenerationSystem Utilizing Low-BTU Landfill Gas
www.southernresearch.orgContact: Tim Hansen, ETV Director, ESTCP [email protected] 919-282-1050
http://www.epa.gov/etv/
ThisworkisfundedunderESTCPproject SI-0823
Recommended
