相平衡大作业

相平衡和状态方程化学化工学院化学工艺专业孙文静1.根据临界性质推导R-K方程的参数方程。（a=?,b=?）解：R-K方程为：==应用于临界状态：（1）(2)把（1）代入（2），得： . (3)由（1），得：（4）（5）由（5），得：（6）把式（6）代入（3），得：＝0.086640把式（6）代入（4）式，得：=0.427480即：a＝0.086640b=0.4274802.用UNIFAC法求乙醇和苯的活度系数，温度为345K，组成X1=0.2解：乙醇有1个CH3基团，1个CH2基团和1个OH基团，苯有6个ACH基团，参数见下表：参数查流体相平衡原理及其应用（M）朱自强主编浙江大学出版社1990P324-325基团乙醇苯)RkQkCH3CH2OHArCH111000010.90110.67441.00000.53130.8480.5401.20000.40000101986.50.0573156.40.635561.130.8376-11.21.0328986.50.0573156.40.635561.130.8376-11.21.032889.60.7712636.10.1582..基团.0.03701/3.00.03701/300.03701/300.888901基团0.06960.3277-0.04430.2087-0.09850.4637-0.7877-1基团0.98990.831000.98990.831000.22960.494400.9590-1基团0.82760.6991-0.82760.6991-OH1.13541.3840-ArCH1.008-1基团0.15480.4121-0.09860.2624-1.60320.4277-0.0135-03.SOAVE方程同时应用于汽液两相计算2.0MP时，丙烯（1）＋异丁烷（2）在全浓度范围内T,Px,y的相平衡数据解：查出有关物性数据如下表：组分有关计算公式如下：.(1).求解步骤：输入已知的数据，假设一个温度和组成；由方程（1）求解压缩因子，对汽相（使用组成）取其最大根，对液相（使用组成）取其最小根教学方出和以后由（2）式计算逸度系数，于是可求出用新的重新试差，返回去试差以前应该把归一化；用检验是否收收敛。如果＞,则调整温度重新试差。计算结果见下表：表1：SOAVE方程计算2Mpa丙烯(1)—异丁烷(2)平衡体系的结果φ1φ2φ1Vφ2VZVZL0.000372.68001.51390.75570.90060.75570.66730.10080.050.0821369.45001.46840.72330.89440.74870.66620.09920.100.1603366.29001.42330.69200.88800.74170.66560.09760.150.2346363.20001.37880.66170.88160.73490.66530.09610.200.3050360.17001.33470.63250.87510.72810.66540.09470.250.3717357.21001.29160.60440.86870.72150.66600.09330.300.4347354.32001.24930.57740.86220.71510.66700.09200.350.4941351.50001.20810.55160.85570.70880.66840.09070.400.5501348.76001.16810.52700.84940.70280.67030.08950.450.6072346.08001.12910.50340.84300.69700.67260.08830.500.6522343.491.09150.48110.83690.69150.67540.08710.550.6985340.96001.05510.45970.83080.68620.67860.08600.600.7419338.50001.01990.43950.82490.68130.68220.08480.650.7825336.12000.98620.42030.81920.67660.68620.08370.700.8205333.81000.95370.40210.81360.67220.69060.08260.750.8560331.58000.92260.38490.80830.66830.69530.08150.800.8890324.41000.89270.36860.80330.66450.70030.08050.850.9198327.31000.86400.35320.79840.66120.70560.07940.900.9485325.28000.83660.33860.79390.65810.71120.07830.950.9751323.32000.81050.32490.78960.65540.71700.07731.001.0000321.43000.78560.31200.78560.65310.72310.0763表2：丙烯(1)—异丁烷(2)体系在2Mpa下的VLE数据x1（液相组分中丙烯浓度mol%）y1（汽相组分中丙烯浓度mol%）T（泡点温度K）0.000372.68000.050.0821369.45000.100.1603366.29000.150.2346363.20000.200.3050360.17000.250.3717357.21000.300.4347354.32000.350.4941351.50000.400.5501348.76000.450.6072346.08000.500.6522343.490.550.6985340.96000.600.7419338.50000.650.7825336.12000.700.8205333.81000.750.8560331.58000.800.8890329.41000.850.9198327.31000.900.9485325.28000.950.9751323.32001.001.0000321.43002Mpa下丙烯(1)—异丁烷(2)汽液平衡体系的T-x-y图附：原程序（MATLAB6.5语言程序）%使用Soase(RKS)状态方程计算泡点温度及组成%1：物性数据Propene丙烯Tc1=365k,Pc1=4.62Mpa,w1=0.148%2：物性数据isobutane异丁烷Tc2=408.1k,Pc2=3.648Mpa,w2=0.176tic%开始计时Tc1=365;Pc1=4.620;w1=0.148;Tc2=408.1;Pc2=3.648;w2=0.176;%总压P=2.0MpaP=2.000;m1=0.48+1.574*w1-0.176*w1^2;m2=0.48+1.574*w2-0.176*w2^2;aTc1=0.42748*(8.314*Tc1)^2/Pc1;aTc2=0.42748*(8.314*Tc2)^2/Pc2;b1=0.0866*8.314*Tc1/Pc1;b2=0.0866*8.314*Tc2/Pc2;forx1=0:0.05:1x2=1-x1;forT=310:0.01:378.10Tr1=T/Tc1;Tr2=T/Tc2;%童景山书aTr=[1+m(1-Tr1^0.5)]^2;aTr1=(1+m1*(1-Tr1^0.5))^2;aTr2=(1+m2*(1-Tr2^0.5))^2;a1=aTc1*aTr1;a2=aTc2*aTr2;%烃烃二元体系混合规则,二元交互作用参数kij=0a12=(a1*a2)^0.5;b12=(b1+b2)/2;a=a1*x1.^2+2*a12*x1*x2+a2*x2.^2;b=b1*x1.^2+2*b12*x1*x2+b2*x2.^2;A=P*a/(8.314*T)^2;B=P*b/T/8.314;%ai的平均值用avi表示av1=2*(x1*a1+x2*a12);av2=2*(x1*a12+x2*a2);%bi的平均值用bvi表示bv1=2*(x1*b1+x2*b12)-b;bv2=2*(x1*b12+x2*b2)-b;H1=A-B-B^2;H2=A*B;%求z^3-z^2+z*H1-H2=0的根eq=[1,-1,H1,-H2];z=roots(eq);zv=max(z);zL=min(z);%求逸度系数L,V,液相为L，汽相为VL1=exp(bv1*(zL-1)/b-log(zL-B)-A/B*(av1/a-bv1/b)*log(1+B/zL));L2=exp(bv2*(zL-1)/b-log(zL-B)-A/B*(av2/a-bv2/b)*log(1+B/zL));V1=exp(bv1*(zv-1)/b-log(zv-B)-A/B*(av1/a-bv1/b)*log(1+B/zv));V2=exp(bv2*(zv-1)/b-log(zv-B)-A/B*