Department of Chemistry, National University of Singapore, 3 Science Drive 3, Kent Ridge, Singapore, 117543, Singapore.
Chem Asian J. 2020 Dec 14;15(24):4199-4214. doi: 10.1002/asia.202001023. Epub 2020 Nov 19.
Butadiene is an important monomer for synthetic rubbers. Currently, the annual demand of ∼16 million tonnes is satisfied by butadiene produced as a byproduct of steam naphtha cracking where ethylene and propylene are the main products. The availability of large amounts of shale gas and condensates in the USA since about 2008 has led to a change in the cracker feed from naphtha to ethane and propane, affecting the amount of butadiene obtained. This has provided the impetus to look into direct processes for butadiene production. One option is the eco-friendly conversion of (bio) ethanol to butadiene (ETB). This process had been developed in the 1930s in the then Soviet Union. It was operated on a large scale in USA during World War II but has since been abandoned in favour of petroleum-based processes. The current trend, driven both by the availability of the raw material and ecological considerations, may make this process feasible again, particularly if the catalytic systems can be improved. This critical review discusses recent catalysts for the ETB process with special focus on the development since 2014, benchmarking them against earlier systems with a large database of operational experience.
丁二烯是合成橡胶的重要单体。目前，每年约 1600 万吨的需求是通过蒸汽石脑油裂解生产的丁二烯来满足的，其中乙烯和丙烯是主要产品。自 2008 年左右以来，美国大量页岩气和凝析油的出现改变了裂解原料从石脑油到乙烷和丙烷的情况，这影响了丁二烯的产量。这促使人们研究丁二烯生产的直接工艺。一种选择是将（生物）乙醇环保转化为丁二烯（ETB）。该工艺于 20 世纪 30 年代在当时的苏联开发。在第二次世界大战期间，它在美国大规模运行，但此后已被放弃，转而采用基于石油的工艺。目前的趋势，一方面是由于原材料的可用性，另一方面是出于生态考虑，可能使该工艺再次可行，特别是如果可以改进催化体系。这篇综述讨论了 ETB 工艺的最新催化剂，特别关注自 2014 年以来的发展情况，并使用大量的操作经验数据库对其与早期系统进行了基准比较。
