待生剂上焦炭部分氧化制CO本征反应动力学

INTRINSIC REACTION KINETICS OF PARTIAL OXIDATION OF COKE TO CO ON SPENT CATALYST

制备了碳含量(w)为1.7%的待生剂作为焦炭反应的原料,在反应温度510~780℃区间内,开展了以制CO为目的的焦炭部分氧化本征反应动力学研究,获得了不同反应环境下碳转化速率的本征反应动力学参数。实验结果表明:低于780℃时,在碳-水体系中,碳、水的反应级数为零级,碳气化反应的活化能和指前因子分别为161.23kJ mol和116.2s^(-1);在碳-氧-水体系中,当氧和水过量时,碳的反应级数为一级,氧、水的反应级数为零级,待生剂上碳含量(w)低于0.5%时,在510~665℃下碳气化反应的表观活化能和指前因子分别为38.22kJ/mol和1.37s^(-1);在碳-氧-水体系中,当碳和水过量时,氧的反应级数为一级,碳、水的反应级数为零级,碳气化反应的本征活化能和指前因子分别为79.74kJ/mol和311712s^(-1);在反应温度低于800℃时,CO主要由碳和氧反应生成,待生剂上碳与氧反应初始生成CO与CO2的摩尔比λ与温度T的关系为:λ=8.31e(-16736(RT))。

Spent catalyst with 1. 7% of carbon content was prepared as the material for kinetic study. The intrinsic reaction kinetics of partial oxidation of carbon was investigated at the reaction temperatures ranging from510 ℃ to 780 ℃. The kinetic parameters of carbon conversion were obtained for various reaction conditions. For the coke-water system,when the gasification of carbon conducts at below 780 ℃ with present of excessive carbon,the gasification of carbon follows zero-order reaction with the activation energy and the frequency factor of161. 23 k J/mol and 116. 2 s^（-1）,respectively. For the coke-oxygen-water system when the carbon content of the spent catalyst is less than 0. 5%,and oxygen and water are excessive,the carbon gasification in the temperature range of 510—665 ℃ is first-order reaction with the activation energy and the frequency factor of 38. 22 k J/mol and 1. 37s^（-1）,and zero-orders for both water and oxygen. When the carbon and water are excessive in the same system,the oxygen consumption follows first-order reaction with the activation energy and frequency factor of carbon being 79. 74 k J/mol and 311 712 s^（-1）,respectively. Experimental results indicate that the formation of CO is mainly from the reaction of carbon and oxygen at the reaction temperatures below 800 ℃. The relationship between the value of λ（ CO/CO2mole ratio） and reaction temperature T is λ=8. 31e^（-16 736（ RT））.