5A分子筛分离重整抽余油过程中结焦及再生行为和微结构分析

COKING AND REGENERATED BEHAVIORS OF 5A MOLECULAR SIEVE IN SEPARATION OF REFORMATE RAFFINATE AND ITS MICROSTRUCTURE ANALYSIS

为实现吸附-精馏耦合由重整抽余油生产高纯度正己烷工艺的长周期运行,采用微结构分析方法研究了烯烃在5A分子筛孔道中的结焦行为及失活分子筛的再生工艺。结果表明,重整抽余油中的烯烃是引起分子筛结焦失活的主要因素。对于结焦5A分子筛,以空气为再生气体,在空速为720 h^(-1)、温度为350℃的条件下再生1 h,吸附活性可以达到新鲜5A分子筛的96%以上。通过比表面积、孔径、孔体积分布等微结构分析可知,经过再生之后的分子筛基本恢复了新鲜分子筛的结构特征。

In order to prolong the running cycle of producing high purity n-hexane from reformate raffinate through adsorption-distillation technology, coking of olefins in the channels of 5A molecular sieve and regeneration of coked 5A molecular sieve were studied by microstructure analysis. Results indicated that the existence of olefins in the reformate raffinate was the major factor engendering the deactivation of 5A molecular sieve. For the coked 5A molecular sieve, using air as regeneration gas at a space velocity of 720 h-1 , a regeneration temperature of 350℃ and a regeneration time of 1 h, the activity of the regenerated molecular sieve could reach 96% of that of the fresh one. The analysis results of specific surface area, pore size and pore volume showed that the microstructure of the regenerated molecular sieves was close to that of the fresh one.