生物质流化床气化实验研究与模拟

华中科技大学硕士学位论文生物质流化床气化实验研究与模拟姓名：赵向富申请学位级别：硕士专业：热能工程指导教师：陈汉平20061108ICO2N2CO21CO2ER850ER=0.10.31.11.6m3/kg4.59.5MJ/m3ER0.20.28ERCOH2ASPENPLUSGibbsRYieldRGibbsASPENPLUSIIABSTRACTBiomassisanidealrenewableenergywithadvantagesofabundanceresourcesandneutralingreenhousegascirculation.Theaimofbiomassgasificationistoobtaincombustiblegasproduct,suchasCO,H2,CH4,etc.Inthispaper,anexperimentalstudyonbiomassatmosphericairgasificationwasperformedinfluidizedbed.Fromthepointviewofmechanism,experimentandmodeling,thegasificationofbiomasswascomprehensiveanalyzed.Firstly,theinvestigationsofpyrolysisandchargasificationofthreekindsofbiomass(sawdust,peanutshellandricestraw)werepreformedusingThermogravimetricanalysis.KineticparameterswerecalculatedbasedonTG-DTGcurves.Theresultsshowedthatthemodelofpyrolysismechanismwasfirst-ordermodel.Themodelofchargasificationwasunreactedshrinkingcoremodel.ThereactivityofsawdustcharwasobviouslyhigherthanrichstrawwithCO2asgasifyingagent.Secondly,atmosphericairgasificationofbiomasswasperformedinpilot-scalefluidizedbed.Themaininfluencingfactors(equivalenceratio,bedtemperature,addingsteamandaddingcatalyst)werestudiedindetail.Theresultsshowedthatthegasyieldwas1.1-1.6m3/kg,theheatingvaluewas4.5-9.5MJ/m3,asthetemperatureat850withequivalenceratiovariantfrom0.1to0.3.ItwasobservedthattheoptimalrangeofERisat0.2-0.28.Theheatingvalueandgasificationefficiencyweredecreasedwithequivalenceratioincreasing.TheCOcontentandcarbonconversionefficiencywereincreasedwithtemperature.It’sfavorableforH2upgradingwithsteamaddition.Thevolumecontentofcombustiblegaswasincreasedwiththeadditionofdolomite.Thirdly,basedonASPENPLUS,abiomassgasificationmodelbythemethodofGibbsfreeenergyminimizationwasapproached.UsingtheRYieldblockandRGibbsblock,themodelwasmodifiedbytherestrictedequilibriumoftheRGIBBSreactor.Itwasfoundthatthesimulationresultsfitwellwiththeexperimentresults.Themodelwasprovedreliable.Simultaneously,themodelwasusedtosimulatethepilotfluidizedbedandgasificationpowerplant,it’sprovedthatthemodelcanbeappliedwidely.Keywords:biomassgasification,fluidizedbed,model,ASPENPLUS□______□“√”111.1200419.769.0%48.5%205040483422004SO22254.958.6200520022442010302202538820057%202015%4CO214%[1]6.520107.265200438390080020.51%72018.46%2305.90%20105.75%200532020101350203050%15%35%220062015202015%3000440500010002001.2CHONS[2]2261262COHOCHOO+→+[3]1-11-13[4]IGCC[5]BIGCC1.3800-900COH2CH4CO2(LHV)4-6MJ/Nm312-18MJ/Nm3,40MJ/Nm31996IGCC[6]6MW9MW32BattelleIGCC16-18MJ/Nm3[7]5-10BIGCCMW[8]20054[9]1-11-1200539200412002005140013035080%2116MariaP.Aznar[10]COH273Hanaoka,Toshiaki[11]CaOCO2H2[12]CO2H251.412750850GibbsCorella[13,14]12Sadaka[15]GibbsMansaray[16]PhilippeMathieu[17]ASPENPLUS[18],,PASICALDELPHI,FBGB[19]CFDIGCCASPENPLUS61.5[20-24][25,26]2111TGA23ASPENPLUSGibbs45211721.20-1302.200-4003.400[27][28-33]Dai[34]Encinar(300-900°C)600°C40-60%20-40%10-25%200-300C-O-CC-C220-325200-500310-420(500)()8NETSCHSTA40910K/min20mgN2100ml/min2.1RT-3410020mgSTA-409STA-409(STA)TGDSC/DTGTGDTA/DSCSTATGDTA/DSCTGDTA/DSCSTA2-1N2N2100ml/min10K/min800CO2100ml/min60min2-1(wt.%)(wt.%)MadVadAadFCadCHNSOLHV(MJ/kg)6.1174.63.4715.8245.766.740.07047.4215.288.8468.484.6917.9946.153.071.270.0749.4416.034.1367.7713.5614.5443.902.980.980.0352.1113.52TGDTG2-12-22-31100TG91002100-200TG3200-4002-4200-4007544002-4250-10-8-6-4-20010020030040050060070080020406080100TG(%)DTG(%/min)-5-4-3-2-101010020030040050060070080020406080100TG(%)DTG(%/min)2-1TG-DTG2-2TG-DTG-7-6-5-4-3-2-101010020030040050060070080020406080100TG(%)DTG(%/min)0100200300400500600700800204060801002-3TG-DTG2-4TG102.2(EA)(2.1)(2.2)Biomass(s)→Char(s)volatile(g)(2.1)()dkfdtαα=(2.2)αk)(αfα∞−−=∞wt(T)kArrheniusexp(/)kAERT=−(2.3)A(min1)E(J/mol)R(R=8.314J/K•mol)(2.2)(2.3))(expααfRTEAdtd−=(2.4)EA2.2.1(2.5)110()exp()tEGAdtktRTα=−=∫(2.5)∫=αααα0)()(fdGEA2tG−)(α,αt,ARTEkln/aln+−=Tk/1ln∝EA2.2.2β,dtdT/=βEA(2.4)RTEAfdtd−=ln)(/lnαα(2.6)Tx1==)(/lnααfdtdyREa−=Abln=(2.6)baxy+=ab(2.6)EADTGdt/dα(2.4)0()()()xdaAEGapxfaRβ==∫(2.7)122232!3!4!()1xepxxxxx−=−+−+/xERT=()px2/2()1ERTARTRTGaeEEβ−=−(2.8)E2RTERT21−≈1(2.8)2()lnlnGEARTRTEαβ=−+(2.9)()Ga2)(lnTaG~T1RE−A2.2.3[35-38][39,40](1-a)nn2/31.01.52.02.5nnnn=12-1R0.99-E/RTnn=1n=1131.551.601.651.701.751.80-16-14-8-6-4ln(G(a)/T2)&ln(da/dt/f(a))103/Tf(a)=(1-a)2-1n=1TG-DTGDTGnn=12-1100kJ/mol2-12.3CO2[41]N2800CO2100ml/min60minDTGEkJ/molA(s-1)R257-391365105.32.92*1060.999220-36033377.732.79*1040.999259-393339100.61.86*1060.996142-110min50min[42]2/3()(1)fαα=−(2.5)k2-120min900-20min2k2-1kR0-10min344.450.990-20min1067.030.9801020304050600.00.20.40.60.81.0min8002-1152.4STA-409N21.100100-200200-4004002502.n=1105.3kJ/mol100.6kJ/mol77.73kJ/mol3.344.451067.03163800-900COH2CH4CO21.COOC↔+221(3.1)22COOC↔+(3.2)2222COOCO+↔(3.3)2.22CCOCO+↔(3.4)3.22HCOOHC+↔+(3.5)242CHCH+↔(3.6)222HCOOHCO+↔+(3.7)24222COHCHCO+↔+(3.8)43.4CO2850CO2CO850CO1200CO2COCO3.6800173.78509003.83.63.83.64-8MJ/Nm3(/)12-18MJ/Nm3()40MJ/Nm3()3.1211COH2F-T10kg/h183-13m7kg/h30036cm233-13.1.1200r/min1