苯乙烯在4种分子筛催化剂上的催化裂化规律

Catalytic cracking of styrene over four zeolite catalysts

采用小型固定流化床(ACE Model C),模型化合物苯乙烯在USY-C、REY-C、ZRP-C、Beta-C催化剂上催化裂化转化规律。结果表明,苯乙烯在分子筛催化剂上的转化率由高到低的顺序是:Beta-C>USY-C>REY-C>ZRP-C,主要发生氢转移反应、烷基侧链裂化反应、烷基转移反应和脱氢缩合反应,其中氢转移是苯乙烯催化裂化过程中最主要的化学反应;Y分子筛催化剂对焦炭和大分子产物的选择性高,ZRP-C和Beta-C催化剂对小分子的裂化气体选择性高。随着反应温度的升高,不利于氢转移反应,苯乙烯的特征产物和转化率随质量空速的升高降低,质量空速对苯乙烯催化裂化反应的影响比反应温度大。

The catalytic cracking conversion of model compound styrene on USY-C,REY-C,ZRP-C and Beta-C catalysts was conducted in a small fixed fluidized bed(ACE Model C).The results show that the conversion of styrene on the molecular sieve catalyst is in the order from high to low:Beta-C>USY-C>REY-C>ZRP-C,hydrogen transfer reaction,alkyl side chain cracking reaction,alkyl transfer reaction and dehydrocondensation reaction mainly occur,among which hydrogen transfer is the most important chemical reaction in the catalytic cracking process of styrene;Y zeolite catalyst has high selectivity for coke and macromolecular products,and ZRP-C and Beta-C catalysts have high selectivity for small molecule cracking gas.With the increase of reaction temperature,it is not conducive to the hydrogen transfer reaction.The characteristic product and conversion of styrene decrease with the increase of mass space velocity.The influence of mass space velocity on the catalytic cracking reaction of styrene is greater than the reaction temperature.