(683f) Tuning 1,3-Butadiene Selectivity from Ethanol with Induction Heating

1,3-butadiene, the main petrochemical for rubber production, can be produced from biomass ethanol rather than fossil feedstocks. Although ethanol-to-1,3-butadiene (ETB) reaction can occur in a single step in the Lebedev process, adding acetaldehyde to the feed can significantly improve the selectivity to 1,3-butadiene at a lower temperature, as a result, the Ostromislensky process can be more effective for 1,3-butadiene production. Our results show that the first step of ethanol-to-acetaldehyde over Cu can be lowered to 215 ËšC with induction heating (IH), and the second step of ethanol and acetaldehyde-to-1,3-butadiene is preferred above 300 ËšC. Having each step perform at its preferred temperature can reduce energy consumption, produce fewer side products, and improve the selectivity to 1,3-butadiene. This can be achieved by applying IH to a tandem system, through which the heat is provided by the hysteresis loss from the susceptors and can be controlled to create two temperature zones in one reactor.
Our results of the tandem system show that the selectivity to C4 products, including 1,3-butadiene and butene isomers, are improved compared with the single bed system with the pure ethanol feed. While the selectivities to 1,3-butadiene and butene isomers over 4wt% ZrO2/SiO2 catalyst with IH are 1.88% and 1.97%, respectively, the tandem system can achieve 1,3-butadiene and butene isomers selectivities of 29.2% and 14.5%, respectively, showing its potential to improve the selectivity to C4 products by providing acetaldehyde and H2 to the second catalyst bed and controlling the temperatures separately for each reaction step. Adjusting the temperature and the space velocity can further improve selectivity. Applying induction heating to the ETB tandem reaction can control reaction temperatures individually for the first time, a breakthrough technology for reducing carbon footprint and increasing product efficiency.