以 C2~ C4烯烃作为碳四烯烃催化裂解制乙烯和丙烯反应系统模型，借助吉布斯自由能最小原理对碳四烯烃裂解过程进行热力学计算。结果表明，随着温度升高，乙烯平衡收率升高，610℃时，丙烯平衡收率达44.8%。在丁烯裂解过程中，随着压力降低，乙烯平衡收率升高，压力低于0.1 MPa 时，随着压力降低，乙烯平衡收率升高速率加快，由0.1 MPa 时的21.8%升至0.01 MPa时的46.5%。压力在（0.05~0.8）MPa 时，随着压力降低，丙烯平衡收率缓慢升高，0.05 MPa时达45%，之后迅速下降。热力学计算结果与实验结果比较显示，实验温度范围，1-丁烯在 ZSM -5分子筛催化剂上催化裂解过程中乙烯和丙烯的收率以及丁烯转化率随温度的变化趋势同热力学计算结果一致。从提高丙烯收率的角度，建议温度（500~580）℃，压力0.05 MPa。%Using C2 - C4 olefins as reaction model of production of propylene and ethylene from catalytic cracking of C4 olefins,the thermodynamics performance for C4 olefins cracking was calculated based on the principle of minimum gibbs free energy. The results showed that equilibrium yield of ethylene increased with the increase of temperature,and equilibrium yield of propylene reached 44. 8% at 610 ℃. On the other hand,equilibrium yield of ethylene enhanced with the decrease of pressure at 580 ℃ , especially while pressure was below 0. 1 MPa,the equilibrium yield of ethylene had a rapid increase from 21. 8% at 0. 1 MPa to 46. 5% at 0. 01 MPa;equilibrium yield of propylene increased slightly with the decrease of pressure at the range of(0. 05 - 0. 8)MPa,and reached 45% at 0. 05 MPa and subsequently decreased rapidly. The comparison of thermodynamics equilibrium data and experiment test results showed that the yield of ethylene and propylene and butene conversion from thermodynamics calculation data were in accord with experiment results based on production of propylene and ethylene from butane catalytic cracking over ZSM-5 molecular sieve catalyst. In order to obtain optimum propylene yield,the appropriate reaction condition suggested at reaction temperature range of(500 - 580)℃ and pressure 0. 05 MPa.
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