摘要
针对甲醇制丙烯(MTP)体系反应快,内扩散影响显著的特点,考察了催化剂颗粒大小对反应的影响,提出了床层-颗粒双尺度耦合模型。模型同时考虑了床层及颗粒内的流动、热量和物质传递、以及化学反应在不同尺度上的物理化学过程,较好反映了整个反应器床层不同位置处催化剂粒径对反应结果的影响规律。模拟结果表明,反应器的进料端甲醇浓度高,反应速率快,适合选用小尺寸催化剂颗粒,以减少内扩散的限制;而在反应器床层的中后段,大颗粒催化剂对提高丙烯的选择性更有利。据此提出了MTP反应器不同尺寸颗粒的催化剂组合填充方式。
Considering the fact that MTP reaction possesses the fast reaction rate and significant intraparticle limitation, a coupled model in multi-scale incorporating a single particle model and a fixed-bed model was applied to investigate the effect of catalyst particle size on the reaction rate. The hydrodynamics, mass and heat transfer, chemical reaction, were taken into consideration in the model involving single particle and fixed-bed multi-scale behaviors. This model shows better performance in predicting the impact of catalyst particle size at different locations of reactor. Simulation results indicate that at the feed end, owing to the high concentration of methanol, the reaction rate is fast and small particle size is preferred to reduce the intraparticle diffusion limitation, while at the middle or back end, big particle size is suggested to increase propylene selectivity. Finally, a portfolio method of loading catalyst particle in fixed-bed was recommended.
出处
《化学反应工程与工艺》
CAS
CSCD
北大核心
2015年第1期40-48,共9页
Chemical Reaction Engineering and Technology
关键词
甲醇制丙烯
固定床
颗粒
多尺度模型
methanol to propylene
fixed-bed
particle
multi-scale model
