文献翻译——甲烷检测仪

第1页外文文献资料MethanedetectorMethane(CH4)isthethirdmostabundantgreenhousegas(GHG)butisvastlyunderstudiedincomparisontocarbondioxide.Sourcesandsinkstotheatmospherevaryconsiderablyinestimation,includingsourcessuchasfreshandmarinewatersystems.Anewmethodtodeterminedissolvedmethaneconcentrationsindiscretewatersampleshasbeenevaluated.Byanalyzinganequilibratedheadspaceusinglasercavityring-downspectroscopy(CRDS),lownanomolardissolvedmethaneconcentrationscanbedeterminedwithhighreproducibility(i.e.,0.13nMdetectionlimitandtypical4%RSD).WhileCRDSinstrumentscostroughlytwicethatofgaschromatographs(GC)usuallyusedformethanedetermination,theprocesspresentedhereinissubstantiallysimpler,faster,andrequiresfewermaterialsthanGCmethods.Typically,70-mLwatersamplesareequilibratedwithanequivalentamountofzeroairinplasticsyringes.Theequilibratedheadspaceistransferredtoaclean,drysyringeandthendrawnintoaPicarroG2301CRDSanalyzerviatheinstrumentspump.Wedemonstratethatthisinstrumentholdsalinearcalibrationintothesub-ppmvmethaneconcentrationrangeandholdsastablecalibrationforatleasttwoyears.ApplicationofthemethodtoshipboarddissolvedmethanedeterminationinthenorthernGulfofMexicoaswellasriverwaterisshown.Concentrationsspanningnearlysixordersofmagnitudehavebeendeterminedwiththismethod.Thistopicalreportrepresentsapathwaytowardbetterunderstandingoftheimpactofmarinemethanehydratesonsafetyandseafloorstabilityandfuturecollectionofdatathatcanbeusedbyscientists,engineers,managersandplannerstostudyclimatechangeandtoassessthefeasibilityofmarinemethanehydrateasapotentialfutureenergyresource.Ourunderstandingoftheoccurrence,distributionandcharacteristicsofmarinemethanehydratesisincomplete;therefore,researchmustcontinuetoexpandifmethanehydratesaretobeusedasafutureenergysource.Exploringbasinswithmethanehydrateshasbeenoccurringforover30第2页years,buttheseeffortshavebeenepisodicinnature.Tofurtherourunderstanding,theseeffortsmustbemoreregularandemploynewtechniquestocapturemoredata.Thisplanidentifiesincompleteareasofmethanehydrateresearchandeffortssolutionsbysystematicallyreviewingknownmethanehydrate“ScienceChallenges”andlinkingthemwith“TechnicalChallenges”andpotentialfieldprogramlocations.Gasifier-derivedsyngasfromcoalhasmanyapplicationsintheareaofcatalytictransformationtofuelsandchemicals.Rawsyngasmustbetreatedtoremoveanumberofimpuritiesthatwouldotherwisepoisonthesynthesiscatalysts.Inorganicimpuritiesincludealkalisalts,chloride,sulfurcompounds,heavymetals,ammonia,andvariousP,As,Sb,andSe-containingcompounds.Systemscomprisingmultiplesorbentandcatalyticbedshavebeendevelopedfortheremovalofimpuritiesfromgasifiedcoalusingawarmcleanupapproach.Thisapproachhasthepotentialtobemoreeconomicthanthecurrentlyavailableacidgasremoval(AGR)approachesandimprovesuponcurrentlyavailableprocessesthatdonotprovidethelevelofimpurityremovalthatisrequiredforcatalyticsynthesisapplication.GasificationalsolendsitselfmuchmorereadilytothecaptureofCO2,importantintheregulationandcontrolofgreenhousegasemissions.CO2capturematerialwasdevelopedandinthisstudywasdemonstratedtoassistinmethaneproductionfromthepurifiedsyngas.SimultaneousCO2sorptionenhancestheCOmethanationreactionthroughrelaxationofthermodynamicconstraint,thusprovidingeconomicbenefitratherthansimplyconsistingofanadd-oncostforcarboncaptureandrelease.Moltenandpre-moltenLiNaKCO3canpromoteMgOandMgO-baseddoublesaltstocaptureCO2withhighcyclingcapacity.AstablecyclingCO2capacityupto13mmol/gwasdemonstrated.Thiscapturematerialwasspecificallydevelopedinthisstudytooperateinthesametemperaturerangeandthereforeintegrateeffectivelywithwarmgascleanupandmethanesynthesis.Bycombiningsyngasmethanation,water-gas-shift,andCO2sorptioninasinglereactor,singlepassyieldtomethaneof99%wasdemonstratedat10barand330oCwhenusinga20wt%Ni/MgAl2O4catalystandamolten-phasepromotedMgO-basedsorbent.Undermodelfeedconditionsboththesorbentandcatalystexhibitedfavorablestabilityaftermultipletestcycles.Thecleanupforwarmgascleanupofinorganicswasbrokendowninto第3页threemajorsteps:chlorideremoval,sulfurremoval,andtheremovalforamultitudeoftracemetalcontaminants.Na2CO3wasfoundtooptimallyremovechloridesatanoperatingtemperatureof450C.ForsulfurremovaltworegenerableZnObedsareusedforbulkH2Sremovalat450C(5ppmS)andanon-regenerableZnObedforH2Spolishingat300C(40ppbS).ItwasalsofoundthatsulfurfromCOScouldbeadsorbed(tolevelsbelowourdetectionlimitof40ppb)inthepresenceofwaterthatleadstonodetectableslipofH2S.Finally,asorbentmaterialcomprisingofCuandNiwasfoundtobeeffectiveinremovingtracemetalimpuritiessuchasAsH3andPH3whenoperatingat300C.Proof-of-conceptoftheintegratedcleanupprocesswasdemonstratedwithgasifier-generatedsyngasproducedattheWesternResearchInstituteusingWyomingDeckerCoal.Whenoperatingwitha1SLPMfeed,multipleinorganiccontaminantremovalsorbentsandatar-reformingbedwasabletoremovethevastmajorityofcontaminantsfromtherawsyngas.Atar-reformingcatalystwasemployedduetotheproductionoftarsgeneratedfromthegasifierusedinthisparticularstudy.Itisenvisionedthatinarealapplicationacommercialscalegasifieroperatingatahighertemperaturewouldproducelesseramountoftar.Continuousoperationofapoison-sensitivecopper-basedWGScatalystlocateddownstreamfromthecleanupstepsresultedinsuccessfuldemonstration.Tunablemulti-modediodelaserabsorptionspectroscopyformethanedetectionwasdemonstrated.Theexclusivedependenceofthe1318nmlasermodesdistributionontheinputcurrentandtemperaturewasjustified.Stableabsorptionsignalsrelatedtothemethaneconcentrationswereobtainedbasedonsecond-harmonicdetectiontechnique.Areal-timedatarecordingandanalyzingsoftwareprogramwasdevelopedtorealizetheon-linegasconcentrationmonitoring.Ameasurementsensitivityof25ppmmandanaccuracyof0.27%ofthissystemwereachieved.Minecontainsalotofexplosivegaseswillcausehugeeconomiclossesaftertheaccident,andevenendangerthelivesofminers.Withtheextensionofthecontinuousimprovementofthetechnicalmeanstoexpandcoalminingandminingandminingdepthscale,securityrisksonmoreandmore.Gasaccidentsincoalmineaccidentsintheproportionisincreasing.Sodonotputgasaccidentundercontrol,wecannotachievestablecoalmineproductionsafetysituationimproves,第4页itcannotguaranteethesustainedandhealthydevelopmentofthecoalindustry.Therefore,coalminemethanegasforrapidandaccuratedetectionisparticularlyimportantformethanegasdetectioninstrumentsofresearchanddevelopmenthasbeenanissueofconcern.Inordertoensuresafetyofthemine,topreventgasexplosion,theInstitutecoalabroadinthisfieldforaverylongperiodofresearch,thedevelopmentofmanytypesofgasdetectors,buttheexistinggasdetectioninstrumentsarewidespreadvolumelarge,complexinstallation,maneuver,intelligenceandlowdefects.Therefore,developmentofportable,versatile,high-precisionintelligentgasdetectorhasimportantpracticalsignificancetopromotethesafeproductionofcoalindustry.Aportablemethanegasmonitorbasedonaninfraredspectrumabsorptionprinciplehasbeendevelopedusingadual-channelanddual-wavelengthpyroelectricinfrareddetector,activefiltersaroundtheovertoneabsorptionlinesofmethaneat3.31m,referencefiltersaroundthenon-absorptionlinesofmethaneat3.93m,mid-IRLEDs,aminiaturegold-filledcellstructure,temperaturesensorsforgasconcentrationcalibrationandcompensation,anelectricalmodulationsource,andahighlyintegratedintelligentcontroller.Adetailedinvestigationhasbeencarriedouttodesignalow-costportableIRopticalsensorformethanedetectionthatcanoperateinharshenvironmentswithtemperaturevariationsbetween10Cand40C.Theinfrareddetectionopticsprincipleusedindevelopingthissystemismainlyanalyzed.Aprototypebasedonthisdesignshowedanaccuracyof0.05%,whichmeetsthetechnologyrequirementsoflower-powerconsumption,reducedvolume,andwidemeasurementrange.Adetailedinvestigationhasbeencarriedoutonthedesignofalow-costportableopticalsensorformethanedetectionwithasensitivityof1%oftheLowerExplosiveLevel(LEL)formethane(500ppm)andabletooperateinharshenvironmentswithtemperaturevariationbetween20and50C.Thesensordesignisbasedontheuseofnear-IRLEDsoperatingaroundtheovertoneabsorptionlinesofmethaneat1660nmusingastainlesssteeltubetodirectthelightthroughthegastothedetectors.Variousconfigurationsofsource/detectorlayouthavebeenexaminedtoprovideappropriatereferenceandsignalpathsinordertoachievereliablemethanedetectionatLELlevelsinthepresenceoftemperaturevariation.Anoptimumdesignhasbeenidentifiedusingtwodetectors第5页withappropriateopticalfilteringandwithtemperaturestabilisationofthesourceanddetectors.Basedonthisdesign,aprototypeinstrumenthasbeendemonstratedwithanultimatesensitivityof0.2%LELmethane(100ppm).Diodelaserbasedabsorptionspectroscopy(DLAS)iswidelyusedforgasdetectioninvarietyofapplicationsacrosstheenergy,petrochemicalandminingindustries.Recentdevelopmentsinnearandmidinfrareddiodelasershaveimprovedthesensitivityofgasmeasurementbasedonhighresolutionspectraoftargetspecies.Theavailabilityofnear-infrareddiodesthatcanoperateatroomtemperaturehasexpandedtheapplicationofspectroscopytechniqueinhand-heldgasdetectiondevices.DLASinconjunctionwithopticalfibreshasalsobeenappliedforthedistributedsensingandmonitoringofvariousgasesinreal-timebasis.Thispaper,afterintroducingmethanecharacteristicsandsemiconductordiodelasers,comprehensivelyreviewsdevelopmentinspectroscopicmethanesensingtechniquesinaccordancewithmethaneabsorptionlinesinthenearinfraredspectrum.Accordingtooneembodiment,asystemfordetectingandidentifyinggasesincludesapiezoresistivemicrocantilevertransducer,whereindissipationofheatfromthepiezoresistivemicrocantileverintooneormoregasesismeasuredbychangesinanelectricalresistanceofthepiezoresistor,avibratingmicrocantilevertransducer,whereinshiftsaremeasuredinresonantfrequencyofthevibratingmicrocantileverduetoviscousdampingthereofbytheoneormoregases,andasubsystemforcorrelatingthemeasuredresistancechangesandtheresonantfrequencyshiftstotheoneormoregases.Inanotherembodiment,amethodfordetectingandidentifyingoneormoregasesincludesdeterminingdissipationofheatfromamicrocantileverintooneormoregases,anddeterminingshiftsinresonantfrequencyofthemicrocantileverduetoviscousdampingthereofbytheoneormoregases.Othersystems,methods,andcomputerprogramproductsarealsodescribedaccordingtomoreembodiments.第6页中文翻译稿甲烷检测仪甲烷（CH4）是自然界第三丰富的温室气体（GHG），但是相比之下没有二氧化碳那样广为人知。气体的来源和渠道有相当大的不同，来源包括如淡水和海水系统。一种新的确定离散水样中溶解的甲烷浓度的方法已经被探讨出来了。通过使用激光腔衰荡光谱的平衡顶部空间（CRDS），低纳摩尔溶解的甲烷浓度可以有很高的确定性。而CRDS仪器用于甲烷的测定成本大约只有气相色谱仪（GC）的一半，本文中所呈现的基本上是简单，快速，并且需要的材料比用GC更少的方法。通常情况下，70毫升水样品与零空气的塑料注射器是等量平衡的。已平衡的顶部空间经由仪器的泵转移到一个清洁，干燥的注射器，然后就制成PicarroG2301CRDS分析仪。我们证明这种仪器至少在两年内可以保持线性校准甲烷浓度范围到子ppmv并保持稳定。船载此方法应用在检测溶于墨西哥湾北部河水的甲烷已经被证明可行。浓度跨越近6个数量级，已用这种方法确定。本专题报告代表着更好的了解海底甲烷水合物在安全性和未来的数据收集可由科学家，工程师使用海底甲烷水合物的途径，研究气候变化和评估海洋甲烷水合物作为未来潜在的能源资源的可行性。我们所了解的海底甲烷水合物的分布和特性是不完整的;因此，如果甲烷水合物能作为未来的能源发展，研究必须继续。甲烷水合物盆地探索已经存在了30多年，但这些努力已经在本质上是情节。让我们进一步了解，这些努力必须更经常地采用新的技术来获取更多的数据。这个计划通过系统回顾已知的甲烷水合物“科学挑战”，并把它们与“技术挑战”的和潜在的现场程序位置确定甲烷水合物的研究和努力解决不完整的地方。气化炉导出的煤制合成气在催化转化为燃料和化学品的多个领域。原料气必须去除一些杂质，否则毒合成催化剂。无机杂质包括碱金属盐，氯化物，硫化物，重金属，氨，和P，因为，锑，硒化合物。包括多个吸附剂和催化剂床层的系统已被开发用于煤的气化使用一个温暖的清理方法去除杂质。这种方法要比现有的酸性气体去除更多的经济潜力（AGR）方法和改进现有的流程，不提供除杂，是催化合成中的应用所要求的水平。气化本身更容易捕获的CO2，在控制温室气体排放的重要调节。CO2捕获材料的开发和研究中被证明协助生产纯化的合成气甲烷。同时通过CO2吸附的热力学约束松弛提高CO甲烷化反应，从而提供了经济效益，而不是简单地由碳捕获和释放一个附加成本。熔融和预熔linakco3能促进MgO和MgO基双盐捕获CO2的高循环容量。一个稳定的循环CO2量为13毫摩尔/克了。该捕获材料在这项研究中专门开发的在相同的温度范围内操第7页作，因此有效的整合与温暖的气体净化和甲烷的合成。结合合成气的甲烷化，水煤气变换，和在一个反应器中CO2吸附，单程收率甲烷99%在10酒吧和330oc使用20%重量的Ni/MgAl2O4催化剂和熔融相的MgO基脱硫剂时表现出了。新型饲料条件下，吸附剂和催化剂具有良好的稳定性，经过多重测试循环下。对无机物的温暖的气体净化净化被分成三个主要步骤：除氯，硫的脱除，和多种微量金属污染物的去除。碳酸钠被发现最佳去除氯化物在操作温度450C两脱硫再生氧化锌床450C散装H2S去除使用（5ppm的）和H2S抛光300C非可再生的ZnO层（40ppb的）。同时还发现，硫COS能够吸附（低于我们的检测限为40ppb水平）在水的存在下，导致没有检测到滑移的H2S。最后，吸附剂材料包括铜和镍被发现在去除痕量金属杂质如AsH3和PH3经营300C.证明的综合清理过程的概念在有效与气化炉合成气生成使用怀俄明德克尔煤业西部研究院生产的证明。与1SLPM进给操作时，多个无机污染物去除的吸附剂和焦油重整床能原从合成气中去除污染物的绝大多数。一种焦油重整催化剂由于气化炉的使用在这项研究中产生的焦油生产。可以预见，在实际应用中的一个商业规模的气化炉运行在较高的温度下会产生少量的焦油。连续操作的毒药敏感的铜基变换催化剂位于下游的清理步骤导致成功的示范。可调谐多模二极管激光吸收光谱检测甲烷的证明。在1318nm激光模式分布对输入电流和温度的依赖性是有道理的独家。基于二次谐波检测技术得到了稳定的吸收信号，甲烷浓度有关。实时数据记录和分析软件程序的开发，实现在线气体浓度监测。25ppm的测量灵敏度和该系统的精度达到0.27%。矿中含有大量的气体爆炸会造成巨大的经