基于概率方法的二氧化碳氢化反应热力学优化

Thermodynamics optimization for hydrogenation of carbon dioxide based on probability method

为从热力学的角度优化二氧化碳合成低碳烯烃反应的反应性能,基于Gibbs自由能最小化方法对二氧化碳氢化反应进行平衡热力学分析,通过模拟计算得到反应温度、反应压力、进料气氢碳摩尔比对二氧化碳平衡转化率、低碳烯烃选择性及平衡组分摩尔分数的影响。基于概率学理论,建立反应条件对反应性能参数的概率函数,使用NSGA-Ⅱ多目标优化算法对催化反应性能进行多目标优化。结果表明:相比单目标最优化方法,多目标优化方法可使反应系统多个相互矛盾的目标协同达到最优,在提高二氧化碳转化率和低碳烯烃选择性的同时降低催化系统中H2O平衡摩尔分数。

In order to optimize the reaction performance of hydrogenation reaction of CO2to light olefins from a thermodynamics point, the thermodynamics analyses of CO2hydrogenation reaction were conducted based on Gibbs free energy minimization method. The influences of reaction temperature, pressure and feed gas mole ratio of H2/CO2on the CO2equilibrium conversion, the selectivity of light olefins and equilibrium mole fractions of constants were obtained by simulation. Probability theory was used to build the probability functions between reaction conditions and reaction performances. NSGA-Ⅱ multi-objective optimization(MOO) algorithm was used to conduct MOO for the catalytic performances. The results show that MOO method can balance multiple conflicting objectives and obtain a trade-off optimization compared with the method of single-objective optimization. The application of MOO in the catalytic reaction system can simultaneously achieve increment for the CO2conversion and the selectivity of light olefins and decrement for equilibrium mole fraction of H2O.