分离工程工业应用实例：干气脱硫

分离工程工业应用实例：干气脱硫1.工艺计算用的流程简述根据原油的含硫量及加工深度的不同，炼厂干气不同程度地含有H2S等硫化物。例如胜利馏分油催化裂化干气中，含H2S约2.2%(体)。除炼制低硫原油的干气在作为燃料气使用时不需脱硫外，一般炼油厂的干气不管是作为燃料使用还是用作化工装置的原料，都需要先进行脱硫。炼厂气体脱硫方法主要分为两大类。—为干法脱硫，主要用于需要较高脱硫率的场合，常用的有氧化锌法、活性炭吸附法；另一为湿法脱硫，其中使用最普遍的为醇胺法脱硫。我国炼厂干气脱硫绝大多数采用这种醇胺法。醇胺法脱硫是一种典型的吸收—再生反应过程。本算例是以MDEA（甲基二乙醇胺）为吸收剂，在吸收塔内吸收原料气中的H2S(同时吸收CO2和其他含硫杂质)。吸收了H2S水溶液(富液)经升温后在常压的再生塔内借助塔底的重沸器加热解吸将溶液再生。再生后的贫液经冷却后送吸收塔循环使用，再生塔顶的酸性气经冷凝分液后送硫回收装置回收硫磺。其中S10流股为补充的溶剂，它的量应该尽量少，对整个计算很重要。工艺模拟流程见图1-1。12345678910T1E123456789101112131415116T2SP1P1F1S1S2S3S4S7S8S9S10S5S11S6S12图1-1干气脱硫例题模拟流程图2.需要输入的主要参数原料和工艺参数如表2-1和表2-2所示。表2-11原料组成及工艺参数序号组分Kmol/hr1H2S1.2992CO28.7543CO5.8584N2116.1945O230.8876H2O07H2216.8088CH4210.8339C2H465.19810C2H6139.53111C3H619.28212PROPANE19.862131BUTENE9.10314BUTANE9.99115PENTANE0.55516MDEA0流量Kmol/hr854.156温度℃40.000压力MPa1.000表2-2输入的工艺参数项目单位数值吸收塔压力MPa0.75吸收塔压降MPa0.01进料MDEA浓度Wt%20贫液进吸收塔的温度℃36.0贫液进吸收塔的压力MPa1.0吸收塔吸收塔理论板数10再生塔压力MPa0.17再生塔压降MPa0.03富液进再生塔的温度℃110.0再生塔塔顶温度℃50再生塔再生塔理论板数16其它补充MDEA的温度℃36补充MDEA的压力MPa1.03.软件版本采用PRO/Ⅱ软件5.61版流程计算中所用模块见表3-1所示，共6个。表3-1流程计算模块表模块名称代号流程图上的代号入口物流号出口物流号吸收塔COLOMNT-1S7,S2S1,S3再生塔COLOMNT-2S4S9,S5换热器HXE-1S11,S3S4,S6泵PUMPP-1S5S11闪蒸罐FLASHF-1S6S12分离器SPLITTORSP-1S10,S12S8,S74.结果分析迭代收敛后，排出的净化气中H2S含量小于10ppm，符合质量要求，见表4-1。本例中MDEA的补充是很重要的，这样可以使全流程的物料平衡趋于合理。表4-1输出主要物流表ComponentRatesStreamNameS1S2S3S4S5S6DescriptionPhaseVaporVaporLiquidMixedLiquidLiquidTemperatureC36.01840.00039.308110.000117.37649.771PressureKPA750.0001000.000750.362750.362170.56210000.000MolecularWeight20.20620.48824.86624.86624.74424.744ComponentMolarRatesKG-MOL/HRH2S0.0041.2991.8461.8460.5570.557CO20.0008.7548.7548.7540.0000.000CO5.8535.8580.0050.005N2116.131116.1940.0630.063O230.85330.8870.0340.034H2O6.2951315.9581315.9581315.0201315.021H2216.702216.8080.1060.106CH4210.764210.8330.0700.070C2H465.19865.1980.0000.000C2H6139.440139.5310.0910.091C3H619.25519.2820.0280.028PROPANE19.85019.8620.0120.0121BUTENE9.1039.1030.0010.001BUTANE9.9819.9910.0100.010PENTANE0.5550.5550.0000.000MDEA0.00093.65593.65593.65593.655TotalKG-MOL/HR849.984854.1561420.6311420.6311409.2321409.232S7S8S9S10S11S12LiquidLiquidVaporLiquidLiquidLiquid36.00036.00050.00036.000120.14536.0001000.0001000.000150.0001000.00010000.0001000.00024.71024.71039.95422.86824.74424.7440.5500.0071.2880.5570.5570.0000.0008.7540.0000.0000.0050.0630.0341322.24717.7530.93824.9791315.0201315.0210.1060.0700.0000.0910.0280.0120.0010.0100.00093.6561.2570.0001.25993.65593.6551416.45319.01711.39826.2381409.2321409.2325.输入文件GeneratedbyPRO/IIKeywordGenerationSystemversion5.61$Generatedon:TueAug2318:00:452005TITLEPRINTINPUT=PART,STREAM=ALL,RATE=M,WT,FRACTION=M,WT,MBALANCE,&ION=NONETOLERANCESTREAM=0.0005,-0.05DIMENSIONMETRIC,PRES=KPA,STDTEMP=0,STDPRES=101.325SEQUENCESIMSCICALCULATIONTRIALS=50,RVPBASIS=APIN,TVP=37.778,RECYCLE=ALLCOMPONENTDATALIBID1,H2S/2,CO2/3,CO/4,N2/5,O2/6,H2O/7,H2/8,CH4/9,C2H4/10,C2H6/&11,C3H6/12,PROPANE/13,1BUTENE/14,BUTANE/15,PENTANE/16,MDEATHERMODYNAMICDATAMETHODSYSTEM=AMIN,TRANSPORT=PURE,ENTHALPY(V)=SRK,DENSITY(V)=SRK,&ENTROPY(L)=SRK,ENTROPY(V)=SRK,SET=AMIN01,DEFAULTMETHODSYSTEM=NRTL,SET=NRTL01STREAMDATAPROPERTYSTREAM=S2,TEMPERATURE=40,PRESSURE=1000,PHASE=M,&RATE(WT)=17500,COMPOSITION(M)=1,0.15/2,1.011/3,0.6766/&4,13.4197/5,3.5673/7,25.04/8,24.35/9,7.53/10,16.115/11,2.227/&12,2.294/13,1.0514/14,1.1539/15,0.0641,NORMALIZEPROPERTYSTREAM=S7,TEMPERATURE=40,PRESSURE=10000,PHASE=M,&RATE(WT)=35000,COMPOSITION(WT)=6,80/16,20,NORMALIZEPROPERTYSTREAM=S10,TEMPERATURE=36,PRESSURE=1000,PHASE=M,&RATE(WT)=600.001,COMPOSITION(WT)=6,80/16,20PROPERTYSTREAM=S11,TEMPERATURE=120,PRESSURE=10000,PHASE=M,&RATE(WT)=40000,COMPOSITION(WT)=6,80/16,20,NORMALIZEUNITOPERATIONSCOLUMNUID=T1PARAMETERTRAY=10,IO=30FEEDS2,10/S7,1PRODUCTOVHD(M)=S1,BTMS(WT)=S3,35000,SUPERSEDE=ONPSPECPTOP=750,DPCOLUMN=10PRINTPROPTABLE=PARTESTIMATEMODEL=SIMPLE,TTEMP=38,BTEMP=40TEMPERATURE1,38/10,40TOLERANCEEQUILIBRIUM=0.0001,ENTHALPY=0.0001PACKSECTION(1)=1,10,SULZER=M250Y,HEIGHT=5METHODSET=AMIN01HXUID=E1HOTFEED=S11,M=S6,METH=AMIN01COLDFEED=S3,M=S4,METH=AMIN01CONFIGURECOUNTEROPERCTEMP=110FLASHUID=F1FEEDS6PRODUCTV=S12ISOTEMPERATURE=36,PRESSURE=1000METHODSET=AMIN01SPLITTERUID=SP1FEEDS10,S12PRODUCTM=S7,M=S8OPERATIONOPTION=FILLSPECSTREAM=S7,RATE(WT,KG/H),TOTAL,WET,VALUE=35000METHODSET=AMIN01COLUMNUID=T2PARAMETERTRAY=16,IODAMPING=0.8FEEDS4,4PRODUCTOVHD(M)=S9,BTMS(WT)=S5,35000,SUPERSEDE=ONCONDENSERTYPE=PART,PRESSURE=150,TEST=50DUTY1,1/2,16PSPECPTOP=170,DPCOLUMN=30PRINTPROPTABLE=PARTESTIMATEMODEL=CONVENTIONAL,CTEMP=50,TTEMP=110.1,BTEMP=122.3,&RTEMP=122.9TEMPERATURE1,50/2,110.1/15,122.3/16,122.9SPECREFLUX(WT,KG/H),VALUE=4000SPECTRAY=1,TEMPERATURE(C),VALUE=50VARYDUTY=1,2TOLERANCEEQUILIBRIUM=0.0001,ENTHALPY=0.0001PACKSECTION(1)=2,15,SULZER=M250Y,HEIGHT=10REBOILERTYPE=KETTLEMETHODSET=AMIN01PUMPUID=P1FEEDS5PRODUCTM=S11OPERATIONPRESSURE=10000METHODSET=AMIN01RECYCLEDATAACCELERATIONTYPE=BROYDENEND