甲醇制烯烃产品分布影响规律研究

Research on product distribution influences in methanol to olefin

甲醇制烯烃的主要产品为乙烯、丙烯为主的低碳烯烃,因此研究反应条件对产品气分布的影响对于提高双烯收率具有重要意义。文章基于60wt/a工业化MTO装置,研究了反应温度、反应压力、定碳、藏量和循环量等反应条件对产品气分布的影响,结果表明:提高反应温度能够显著提高双烯选择性,同时甲烷含量跟随上升,但当温度>490℃时,乙炔含量明显上升,对后续分离过程不利。低压在一定程度上利于提高乙烯选择性。较高的再生定碳能够提高双烯选择性,降低C_4及C_5^+组分的收率,应将定碳控制在2%以上已获得最大的双烯收率。藏量与循环量影响催化剂停留时间分布,较大的循环量有利于多产乙烯。

The main products of methanol to olefins are ethylene and propylene. Therefore it is important of study the influence of reaction conditions on product distribution for improving the yield. Based on the 60wt/a industrial MTO device,this paper research the effect of temperature,pressure,carbon content,catalyst reserve and circulation rate on the product distribution. Results show that increasing the reaction temperature can significantly increase the selectivity of dienes and methane. When the temperature is above 490℃,the acetylene content increases obviously,which is harmful to the subsequent separation process. Low pressure is beneficial to increase ethylene selectivity. Higher carbon content can improve the selectivity of ethylene and propylene and reduce the yield of C4 and C5＋. The catalyst reserves and circulation affect the residence time distribution of catalyst,and larger cycle is favorable for producing more ethylene.