DMTO再生催化剂经C4/C5+裂解预积炭后对MTO反应性能的影响

采用小型固定流化床,研究了MTO副产物C4/C5^+烯烃在DMTO再生催化剂上的催化裂解反应、预积炭情况,以及预积炭后再生催化剂对MTO反应性能的影响。结果表明:C4/C5^+烯烃可作为原料在DMTO再生催化剂上进行催化裂解,生成乙烯、丙烯,增加双烯产量。在此裂解过程中,DMTO再生催化剂发生预积炭,可以提高MTO反应中双烯的初始选择性,缩短反应诱导期,提高双烯收率;同时,可以减小甲醇的生焦率,降低甲醇消耗。DMTO再生催化剂预积炭会影响催化剂寿命,其经C4/C5^+裂解预积炭过程中碳质量分数以3%左右为宜。

Effect of Pre-coked DMTO Regeneration Catalyst Through C_4/C_5~+ Alkenes Cracking on the MTO Reaction Performance

With small-scale fixed fluidized-bed reactor,a study was made on the catalytic cracking reaction and carbon deposition of C4/C5+alkenes,MTO byproducts,on DMTO regeneration catalyst,and the effect of pre-coked catalyst on the performance of the MTO reaction.The results showed that C4/C5+alkenes could have catalytic cracking on the DMTO regeneration catalyst as raw materials to produce ethylene and propylene,thus increasing their yields.The pre-coked DMTO regeneration catalyst through C4/C5+alkenes cracking could not only improve the initial selectivity of ethylene and propylene,shorten the induction period of MTO reaction and subsequently enhance the yields of ethylene and propylene,but also reduce the coke formation rate of MTO reaction and decrease the consumption of methanol.However,the lifetime of catalyst could be influenced after carbon deposition,so taking many factors into account,approximately 3%of carbon mass fraction through C4/C5+cracking was advisable for DMTO regeneration catalyst.