苯乙烯生產(chǎn)的物料衡算計(jì)算過程案例綜述1.1生產(chǎn)能力的計(jì)算年生產(chǎn)量為5000噸；年工作天數(shù)300天。根據(jù)任務(wù)要求每小時(shí)的生產(chǎn)需達(dá)：（5000×103kg/300天/24h）=694.44kg/h。1.2物料衡算式質(zhì)量守恒定律為物料衡算基礎(chǔ)，由此可得：∑G式中：∑G投入—投入系統(tǒng)的物料總量∑G產(chǎn)品—系統(tǒng)產(chǎn)出的產(chǎn)品和副產(chǎn)品總量∑G回收—系統(tǒng)中回收的物料總量∑G流失—系統(tǒng)中流失的物料總量1.3脫氫反應(yīng)器的物料衡算（1）已知條件A.由于是連續(xù)生產(chǎn)，因此可以確定計(jì)算的基準(zhǔn)為kg/h，所以需要計(jì)算出每小時(shí)產(chǎn)量以及原料的投料量。B.乙苯脫氫反應(yīng)：主反應(yīng)：C6H5C2H5?C6H5C2H3+H2（a）主要副反應(yīng)：C6H5C2H5→C6H6+C2H4（b）C6H5C2H5+H2→C6H5CH3+CH4（c）水蒸氣乙苯質(zhì)量比為1.3:1；乙苯轉(zhuǎn)化率為85%；反應(yīng)選擇性為（a）90%、（b）3%、（c）7%。C.每小時(shí)苯乙烯的流量：694.44kg/hD．原料規(guī)格：乙苯（99%）：含有甲苯0.7%、苯0.2%、焦油0.1%。水蒸氣（95%）：含雜質(zhì)氣體5%。E.（2）物料衡算主反應(yīng)：A．原料進(jìn)入反應(yīng)器的流量理論乙苯的流量=（694.44×106.16）/（104.15×85%×90%×98%）=971.98kg/h實(shí)際乙苯的流量=971.98/99%=981.82kg/h=9.27kmol/h甲苯的流量=981.82×0.7%=6.8867kg/h=0.0747kmol/h苯的流量=981.82×0.2%=1.97kg/h=0.0252kmol/h焦油的流量=981.2×0.1%=0.9832kg/h=0.0033kmol/hB.進(jìn)反應(yīng)器的蒸氣量理論水蒸氣的流量=1.3×971.98=1266.17kg/h實(shí)際水蒸氣的流量=1266.17/95%=1332.81kg/h=74.05kmol/hC．脫氫過程計(jì)算主反應(yīng)：C6H5C2H5?C6H5C2H3+H2（a）轉(zhuǎn)化率為：85%生成的苯乙烯=971.98×85%×104.15/106.16=812.21kg/h=7.80kmol/h生成的氫氣=971.98×85%×2/106.16=15.60kg/h=7.80kmol/h剩余乙苯=971.98×（1-85%）=146.10kg/h=1.38kmol/hD．副反應(yīng)：（1）C6H5C2H5→C6H6+C2H4（b）生成的苯=9.27×85%×3%=0.2364kmol/h生成的乙烯=0.2364kmol/h出料中的苯量=0.0252+0.2364=0.2616kmol/h（2）C6H5C2H5+H2→C6H5CH3+CH4（c）生成的甲苯=9.27×85%×7%=0.5516kmol/h生成的甲烷=0.5516kmol/h消耗的氫氣=0.5516kmol/h出料的甲苯=0.0747+0.5516=0.6263kmol/h出料的氫氣=7.8-0.5516=7.2484kmol/hE．氧化反應(yīng)2H2+O2→2H2O輸入的氧氣=7.2484/2=1.6242kmol/h生成的水=7.2484/hF．總結(jié)上述計(jì)算，得到物料平衡表，如表1、表2所示：表SEQ表格\*ARABIC1脫氫反應(yīng)器的物料平衡表-進(jìn)料進(jìn)料組分Kg/hKmol/h%（mol）%（wt）乙苯981.829.2798.9099.01苯1.970.02520.270.20甲苯6.88670.07470.800.69焦油0.98320.00330.040.10氧氣115.97441.6242水蒸氣1332.8174.05合計(jì)991.65999.3732100100表SEQ表格\*ARABIC2脫氫反應(yīng)器的物料平衡表-出料出料組分Kg/hKmol/h%（mol）%（wt）苯乙烯812.217.8041.0868.63乙苯146.101.387.6212.35甲苯57.70730.62631.464.88苯20.43360.26161.441.73乙烯6.63340.23641.310.56甲烷8.84770.55161.050.75焦油0.98320.00330.020.08水130.47127.248440.0311.03合計(jì)1181.38618.10761001001.4冷凝油水分離階段的物料衡算A．進(jìn)料：設(shè)反應(yīng)器中的反應(yīng)物質(zhì)可以完全流入到冷凝油水分離器苯乙烯=812.21kg/h=7.7kmol/h乙苯=146.10kg/h=1.38kmol/h甲苯=57.7073kg/h=0.6263kmol/h苯=20.4336kg/h=0.2616kmol/h乙烯=6.6334kg/h=0.2364kmol/h甲烷=8.8477kg/h=0.5516kmol/h焦油=0.9832kg/h=0.0033kmol/h水=130.4712kg/h=7.2484kmol/hB．出料：設(shè)冷凝油水分離器可以進(jìn)料物資可以完全流出苯乙烯=812.21kg/h=7.7kmol/h乙苯=146.10kg/h=1.38kmol/h甲苯=57.7073kg/h=0.6263kmol/h苯=20.4336kg/h=0.2616kmol/h乙烯=6.6334kg/h=0.2364kmol/h甲烷=8.8477kg/h=0.5516kmol/h焦油=0.9832kg/h=0.0033kmol/h水=130.4712kg/h=7.2484kmol/hC．總結(jié)上述計(jì)算，得到物料平衡表，如表3、表4所示：表SEQ表格\*ARABIC3冷凝油水分離器的物料衡算表-進(jìn)料進(jìn)料組分kg/hkmol/h%（mol）%（wt）苯乙烯812.217.8041.0868.63乙苯146.101.387.6212.35甲苯57.70730.62631.464.88苯20.43360.26161.441.73乙烯6.63340.23641.310.56甲烷8.84770.55161.050.75焦油0.98320.00330.020.08水130.47127.248440.0311.03合計(jì)1181.38618.1076100100表SEQ表格\*ARABIC4冷凝油水分離器的物料衡算表-出料出料組分kg/hkmol/h%（mol）%（wt）苯乙烯812.217.8041.0868.63有機(jī)相乙苯146.101.387.6212.35甲苯57.70730.62631.464.88苯20.43360.26161.441.73焦油0.98320.00330.020.08乙烯6.63340.23641.310.56甲烷8.84770.55161.050.75水130.47127.248440.0311.03無機(jī)相合計(jì)1181.38618.10761001001.5乙苯/苯乙烯精餾塔的物料衡算油水分離器出口所得的有機(jī)混合物質(zhì)量組成，如表5所示：表SEQ表格\*ARABIC5反應(yīng)出口的有機(jī)混合物質(zhì)量組成組分Kg/hW%苯乙烯812.2178.29乙苯146.1014.08甲苯57.70735.56苯20.43361.97焦油0.98320.09合計(jì)1037.434100.00A．已知：mB．進(jìn)料：苯乙烯=812.21kg/h=7.7kmol/h乙苯=146.10kg/h=1.38kmol/h甲苯=57.7073kg/h=0.6263kmol/h苯=20.4336kg/h=0.2616kmol/h焦油=0.9832kg/h=0.0033kmol/h阻聚劑=1037.4368×0.3%=1.11kg/h=0.0169kmol/hC．出料：設(shè)乙苯/苯乙烯精餾塔的分離率為98%苯乙烯=812.21×98%=795.9658kg/h=7.6425kmol/h乙苯=146.10×98%=141.178kg/h=1.3487kmol/h甲苯=57.7073×98%=56.5532kg/h=0.6138kmol/h苯=20.4336×98%=20.0249kg/h=0.2564kmol/h焦油=0.9832×98%=0.9635kg/h=0.0032kmol/h阻聚劑=1.11×98%=1.0478kg/h=0.0166kmol/hD．總結(jié)上述計(jì)算，得到物料平衡表，如表6、表7所示：表SEQ表格\*ARABIC6乙苯/苯乙烯精餾塔的物料衡算表-進(jìn)料進(jìn)料組分Kg/hKmol/h%（mol）%（wt）苯乙烯812.217.8077.3278.06乙苯146.101.3811.6814.04甲苯57.70730.62636.215.55苯20.43360.26162.591.96焦油0.98320.00330.030.09阻聚劑1.110.01690.170.30合計(jì)1040.54410.0881100.00100.00表格SEQ表格\*ARABIC7乙苯/苯乙烯精餾塔的物料衡算表-出料出料組分Kg/hKmol/h%（mol）%（wt）乙苯141.1781.348711.6514.04塔頂甲苯56.55320.61386.215.55苯20.02490.25642.591.96苯乙烯795.96587.642577.3478.06塔底焦油0.96350.00320.030.09阻聚劑1.04780.01660.170.30合計(jì)1019.7339.8812100.00100.001.6乙苯塔的物料衡算A．進(jìn)料：乙苯=141.178kg/h=1.3487kmol/h甲苯=56.5532kg/h=0.6138kmol/h苯=20.0249kg/h=0.2564kmol/hB．出料：設(shè)乙苯塔的分離率為98%乙苯=141.178×98%=140.3144kg/h=1.3217kmol/h甲苯=56.5532×98%=55.4221kg/h=0.6015kmol/h苯=20.0249×98%=19.6244kg/h=0.2512kmol/hC．總結(jié)上述計(jì)算，得到物料平衡表，如表8、表9所示：表SEQ表格\*ARABIC8乙苯塔的物料衡算表-進(jìn)料進(jìn)料組分Kg/hKmol/h%（mol）%（wt）乙苯141.1781.348760.7865.15甲苯56.55320.613827.6625.73苯20.02490.256411.569.11合計(jì)219.75612.2189100.00100.00表SEQ表格\*ARABIC9乙苯塔的物料衡算表-出料出料組分Kg/hKmol/h%（mol）%（wt）甲苯55.4220.601527.6625.73塔頂苯19.62440.251211.559.11乙苯140.31441.321760.7865.15塔底合計(jì)215.36082.1744100.00100.001.7苯/甲苯塔的物料衡算A．進(jìn)料：甲苯=55.4221kg/h=0.6015kmol/h苯=19.6244kg/h=0.2512kmol/hB．出料：設(shè)苯/甲苯塔的分離率為98%甲苯=55.4221×98%=54.3137kg/h=0.5895kmol/h苯=19.6244×98%=19.2319kg/h=0.2462kmol/hC．總結(jié)上述計(jì)算，得到物料平衡表，如表10、表11所示：表SEQ表格\*ARABIC10