甲醇与戊烯耦合制丙烯的实验研究

在等温固定床反应器中使用高硅铝比的H-ZSM-5分子筛催化剂,考察了温度、空时和进料比例3个反应条件对甲醇与戊烯耦合反应制丙烯的影响。适宜的温度范围为420~500℃,此时甲醇转化率可达到100%,升高温度可提高甲醇转化率和丙烯选择性,并减少副产物烷烃和芳烃的生成;减小空时可减少副产物的产生并提高丙烯与乙烯生成比例,但当空时减小到1~5(g·h)/mol,丙烯生成量减小;耦合反应相比甲醇和戊烯各自单独进料,可明显减少副产物生成,甲醇进料比例的增大能够使丙烯的选择性升高,但戊烯的转化率会降低。n(甲醇)/n(戊烯)为2时,副产物的生成量最小。

Experimental Study on Preparation of Propene by Coupled Reaction of Methanol and Pentene

The effects of reaction temperature, space-time and feeding ratio on the methanol-pente-ne coupled reaction were investigated over H-ZSM-5 catalyst in an isotherm fixed-bed reactor. The appropriate reaction temperature is 420-500 ℃ , within this range the conversion of methanol can reach 100%. Rising temperature can enhance the conversion of methanol and propene selectivity effectively, and also reduce generation of by-products, which are alkanes and aromatics. The space-time won＇ t influence the conversion of methanol. When it is decreased, the product distribution is enhanced effectively. The limit range is above 5 （ g. h）/mol, otherwise the reaction residence time is too short for propene yield. The byproducts are reduced by coupling reaction compared with either separated feed. When the ratio of methanol to pentene is increased, the propene selectivity is enhanced while the conversion of pentene is lessened. The by-products are reduced to minimum when the ratio is 2.