Butadiene Production from Ethanol

Butadiene is one of the most essential basic chemicals at the core of the chemical industry, which is an important ingredient used to make products such as tires, engineering polymers and latex products. Continued use of petroleum to produce butadiene is now widely recognized as unsustainable because of depleting supplies and increase in emissions of greenhouse gas in the environment. Butadiene production from renewable materials, such as bioethanol, has attracted significant interest for environmental and economic sustainability. This article critically reviewed the catalytic conversion technologies for butadiene production from bioethanol considering aspects related to the catalysts, reaction pathways and process developments. Acid-base bifunctional catalysts can facilitate high yield and high selectivity of butadiene. Two main reaction pathways—Prins and 3-hydroxybutanal, and two synthesis processes—single-reactor and two-reactor, were reviewed. The reactors of fixed bed and fluidized bed were discussed With a high-surface-area NiO/MgO · SiO₂ catalyst, a highest selectivity and a maximum yield of 1,3-butadiene reached over 90% and 53 mol.%, respectively in a fixed bed continuous flow reactor by Kitayama et al. (1996).