CH_4催化转化宏观动力学

MACROKINFTIC MODEL FOR CH_4 CATALYTIC REFORMING

使用积分反应器在孔砖型镍催化剂上进行了CH_4、CO_2和水蒸汽转化反应实验,获得了宏观动力学模型。实验数据用指数-样条函数拟合,采用解微分方程组最优化方法确定动力学模型的参数。考虑内扩散影响的宏观反应动力学方程为:R_(CH_4)=1.379×10^(-4)exp(-50032/RT)P_(CH_4)^(3.31)P_(CO_2)^(-2.93)R_(CO_2)=2.150×10^(-4)exp(-86541/RT)P_(CH_(?))^(2.40)P_(CO_2)^(-1.66)(1-Qp/Kp)

The catalytic reaction of CH_4 with CO_2 and steam is studied in an integral flow reactor, over a nickel checkerwork catalyst, at a temperature range of 1218-1373K and under a pressure of 1.08×l0~5Pa. Conversion data based on crude catalyst, with influence of interior mass transfer, were obtained for CO_2/CH_4=0.9 and CO_2/CH_4=1.45(mol ratio), and successfully fitted to an exponential spline function. An approach involving stepwise regression and optimization is used to evaluate kinetic paremeters. Rate equations developed that reasonably represent the experimental data are as follows:R_(CH_4)=1.379× 10^(-4)exp (-50032/RT)P_(CH_4)~3.31P_(O_2)^(-2.93)R_(CO_2)=2.150×10^(-4)exp (-86541/RT)P_(CH_4)~2.40P_(CO_2)^(-1.66)(1-Q_p/K_p)