摘要
综合考虑化学反应速率、内扩散和反应热的影响,建立单个催化剂颗粒表面烧焦过程的数学模型,模拟研究了粒径1 000μm的球形催化剂的表面烧焦过程。研究表明,650℃再生,化学反应速率为控制步骤,催化剂的再生过程符合整体反应模型;800℃再生,内扩散影响严重,碳含量、氧分压沿径向变化剧烈。再生温度升高,催化剂颗粒的瞬时温升增大;催化剂初始碳含量越高、CO2/CO摩尔比越大,催化剂颗粒的瞬时温升越大,但再生过程所需时间增加;催化剂颗粒的径向温度分布均一。在排除外扩散影响的条件下,反应气速对再生过程影响很小。
Taking into account the chemical reaction rate,internal diffusion and reaction heat,the theoretical model of regeneration process was established to investigate the regeneration within large coked catalyst particle.The results showed that at 650 ℃,limited by the chemical reaction rate,regeneration process was characterized by the homogeneous model.At temperature over 750 ℃,internal diffusion of gaseous reactant being the controlling step,the distinct radial profiles of oxygen partial pressure and carbon content were established.The maximum temperature rise in a single spherical catalyst particle increased with the increase of initial regeneration temperature.The maximum temperature rise also increased with the increase of carbon load and CO2/CO mol ratio in product gas.However,the regeneration time needed to reach one burn-off degree was prolonged.The temperature throughout the catalyst particle was homogeneous.The influence of gas flow rate on the regeneration process could be neglected in the case of eliminating external diffusion.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2007年第4期423-430,共8页
Journal of Fuel Chemistry and Technology
基金
国家自然科学基金重大项目(20490202)
教育部新世纪优秀人才支持计划(NCET-04-0107)
关键词
大颗粒
芳构化催化剂
再生
数值模拟
large particle
aromatization catalyst
regeneration
numerical simulation
