液化石油气在MTP反应中的作用

Effects of liquefied petroleum gas co-feeding with the methanol in the MTP reaction

在MTP反应中,考察液化石油气/水蒸汽或水蒸汽与甲醇共进料的反应条件对催化剂寿命和丙烯选择性的影响,并利用热重分析对催化剂结焦情况进行了分析。结果表明,液化石油气/水蒸汽作稀释气时,丙烯选择性较水蒸汽作稀释气时提高了9.9个百分点,200 h内,催化剂结焦质量分数减少7.3个百分点,在两个反应周期,催化剂寿命累计延长250 h,表明液化石油气中C4烯烃与甲醇的耦合作用在MTP反应中起关键作用,可有效提高丙烯选择性,延缓催化剂结焦,提高催化剂寿命。

The effects of methanol co-feeding with the vapor/liquefied petroleum gas （LPG） or vapor merely on the selectivity to propylene and the catalyst lifetime in the methanol to propylene（MTP） reac- tion were investigated respectively. The status of coke deposition over the catalysts was analyzed by TG. Comparing with the methanol co-feeding with the water steam, the selectivity to propylene were increased by 9.9% under the condition of the methanol co-feeding with the vapor LPG;coke amounts accumulated on the catalyst decreased 7.3wt% during 200 h, and the catalyst lifetime was prolonged about 250 h in the two cycle reaction periods. It indicated that the coupling reaction of C4 olefin in the LPG with methanol played a key role in the MTP reaction. Therefore the selectivity to propylene were improved, coke deposition on the catalyst was slowed down and the catalyst service life was prolonged in the condition of methanol co-feeding with the LPG and vapor.