Catalyst screening for dehydration of primary alcohols from renewable feedstocks under formation of alkenes at energy-saving mild reaction conditions

Abstract

Among current challenges for the chemical industry is the shift of the raw material basis from fossil feedstocks to renewable sources, which is also of relevance for the field of the industrial product class of alkenes with a chain length of C₆ or more. A process concept based on CO₂ and renewable energy is the conversion of 1-hexanol, being accessable from such renewable sources, to hexene sources. In this contribution, the dehydration of 1-hexanol catalyzed by Lewis acids such as metal triflates is presented. The prioritized catalysts have been also applied for the dehydration of C₇–C₁₂ primary alcohols. Hf(IV) and Ti(IV) triflates have shown the highest conversions in comparison to 13 other metal triflates, leading to high alkene yields of more than 70%. Furthermore, this study revealed a process running at energy-saving conditions and the so far lowest reaction temperatures for a chemocatalytic dehydration of primary alcohols being in the range of 140–180 °C only.