孔砖型催化剂上 CH_4、CO_2和水蒸汽催化反应宏观动力学模型

MACROKINETIC MODEL OF CH_4-CO_2-STEAM REACTION OVER A CHECKWORK CALALYST

在原型孔砖型催化剂上进行 CH_4、CO_2和水蒸汽催化反应宏观动力学研究。在950—1100℃温区内,获得了如下的动力学模型■R_(CH_4)=0.1109exp(-50010/R_■T)p_(CH_4)^(3.3)·p_(CO_2)^(-2.9)R_(CO_2)=0.3487exp(-86503/R_■T)P_(CH_4)^(2.4)·P_(CO_2)^(-1.7)(1-Q_p/K_p)

The catalytic reaction of CH_4 with CO_2 and steam over a nickel check- work catalyst was studied in an integral flow reactor with the temperature range of 1218-1373 K and at 1.08×10~5 Pa.Conversion data which were influenced by interior mass transfer were obtained for CO_2/CH_4=0.9 and CO_2/H_2O=1.45 (molar ratio).These data were successfully fitted to an exgonential second- polynomial spline function.An approach involving stepwise regression and optimization was used to determine the kinetic parameters.The simulated re- sults obtained by Eq.17 agreed well with the experimental data.This model was developed on the basis of the following mechanism: CH_4+H_2O=CO+3H_2, CO_2+H_2=CO+H_2O. The experimental results showed that the latter reaction is not at equilibrium and its direction is not altered.The results also indicate that the checkwork nickel catalyst can be employed well in the upside of the reformer.