甲烷水蒸汽催化转化的动力学模型

在常压下使用内循环式无梯度反应器研究了Z102镍催化剂上甲烷水蒸汽催化转化反应的动力学。实验条件如下:反应温度500—700℃,H_2O/CH_4=2.5—4.5（克分子比）,甲烷空速为2000—10000ml/h·g-cat。根据实验结果的分析,作者认为在反应过程中一氧化碳和二氧化碳是同时生成的,即甲烷水蒸汽催化转化反应可用平行反应模型来表示。所得到的一氧化碳及二氧化碳的生成速度方程分别为: rco=k,p_(CH_4)~(0.8)及 rco_2=k_2p_(CH_4)~(0.8) p_(H_2O)~(1.5)反应速度常数k_1及k_2与温度的关系均符合阿累尼乌斯方程。一些研究者认为在通常的操作条件下,甲烷水蒸汽催化转化反应过程中,水煤气变换反应很快就达到平衡,我们的实验数据计算证明这个见解是不妥的。

The Kinetic Model for Catalytic Steam Reforming of Methane

The kinetics of methane steam catalytic reforming reaction over Z 102 nickel catalyst had been investigated in internal recycle gradientless reactor at atmospheric pressure. Experimental conditions were as follows:reaction temperature range 500-700℃, H2O/CH4=2.5-4.5 (molar ratio), methane space velocities 2000-10000ml/h.g-cat. According to the analysis of experimental results the authors have considered that carbon monoxide and carbon dioxide are formed together in these reaction process, i. e, catalytic steam reforming of methane may be represented by parallel reaction model. The rate equations of carbon monoxide and carbon dioxide formationwere obtained respectively. The dependencies of reaction rate constants k1 and k2 on temperature can be fitted in with Arrhenius equation.Some investigators considered that water gas shift reaction equilibrium was very rapidly attained in the catallytic steam reforming of methane process under usual operating conditions. Our calculations of experimental data shows that this opinion is incorrect.