C_(4)预积碳对甲醇制烯烃再生催化剂反应性能的影响

Effect of carbon pre-deposition on reaction activity of regenerated catalyst for methanol to olefins

充分转化甲醇制烯烃(MTO)工艺副产物C_(4),可有效提升装置的经济性,是有效增产乙烯和丙烯的重要手段。再生催化剂经C_(4)预积碳后,在催化剂上生成的焦炭起到修饰催化剂的孔道结构、降低分子筛的酸强度和酸密度、进而缩短MTO反应的诱导期,提高目的产物收率的作用。基于某公司1.8×106 t/a的MTO工业装置,分析了在不同负荷下C_(4)预积碳对MTO反应过程组分变化的影响。实验结果表明,C_(4)预积碳可降低甲醇单耗;低负荷下,C_(4)预积碳利于丙烯生成;高负荷下,利于乙烯生成;同时,C_(4)预积碳的经济性主要取决于乙烯和丙烯的价格,如果乙烯和丙烯的价格均高于C_(4),则进行C_(4)预积碳经济性好。

The full conversion of C_(4),a by-product of methanol to olefins(MTO)process,can effectively improve the economic efficiency of the plant and is an important means to increase the production of ethylene and propylene.After the regeneration catalyst is pre-deposited with C_(4),the coke generated on the catalyst modifies the pore structure of the catalyst,reduces the acid strength and density of the molecular sieve,and thus shortens the induction period of MTO reaction,increasing the yield of the target products.Based on a 1.8×106 t/a MTO industrial plant of a certain company,the effect of C_(4) pre-deposition on the composition changes of the MTO reaction under different loads were analyzed.The results show that C_(4) pre-deposition can reduce the methanol consumption,and is conducive to the propylene production under low load and ethylene production under high load.Meanwhile,the economic feasibility of C_(4) pre-deposition mainly depends on the prices of ethylene and propylene,and if the prices of ethylene and propylene are higher than C_(4),then C_(4) pre-deposition is more economical.