异丁烯选择性叠合工艺及优化措施

Isobutene selective oligomerization process and optimization measures

关键词:  异丁烯选择性叠合  抑制剂  叔丁醇  反应器温升  二聚物  列管式反应器  侧线反应器

Key words:  isobutene selective oligomerization  inhibitor  tert butyl alcohol  reactor temperature rise  dimer  tubular reactor  side-reactor

摘要:

异丁烯选择性叠合工艺将异丁烯选择性地叠合为二异丁烯,是C₄资源利用的有效途径之一。针对该工艺特点,论述了在原料中加入醇类等极性组分可有效降低多聚物的生成,并提高目的产物的选择性,指出了采用TBA做抑制剂时产品中不含醚类氧化物,且可通过补水的方式来弥补TBA损失。当原料中异丁烯质量分数大于25%时,需要采取一定的措施以控制因较强的放热反应造成的反应器温升,其中采用列管式反应器或在原料中加入惰性组分如异辛烷等都是行之有效的措施。由于催化蒸馏塔存在结构复杂、塔高因塔内装有大量催化剂易超过70 m等缺陷,建议采用新型侧反应器-精馏塔集成结构取代催化蒸馏塔,该结构既保持了催化蒸馏塔能量利用率高的优点,又避免了该塔复杂的结构设计。国内对异丁烯选择性叠合工艺的开发与应用处于起步阶段,建议进一步加强对该工艺的研究,以期为国内C₄资源的有效利用提供更好、更强有力的技术支持。 

Abstract:

Isobutene can be selectively dimerized into diisobutene by isobutene selective oligomerization process, which can effectively utilize C_4s resources. According to the characteristics of this process, it is discussed that adding polar components such as alcohols in feeds can effectively reduce the formation of polymers and improve the selectivity of target products. It is pointed out that when TBA is used as an inhibitor, there is no ether oxides in the product, and the loss of TBA can be compensated by adding water. When the mass fraction of isobutene in the feeds is more than 25%, some measures should be taken to control the temperature rise of the reactor caused by the strong exothermic reaction, among which using the tubular reactors or adding inert components such as isooctane into the feeds are effective measures. Due to the defects of complex tower internals and tower height easily exceeding 70 m caused by the large amount of catalysts in the tower, a new type of side-reactor column configuration is proposed to replace the catalytic distillation column. This structure not only maintains the advantage of high energy utilization in catalytic distillation process, but also avoids complex structure design. The development and application of isobutene selective oligomerization process is still in its infancy in China. It is suggested to further strengthen the research on this process in order to provide a better and more powerful technical support for the effective utilization of C_4s resources in China.