(563g) Improving 1,3-Butadiene Selectivity with an Induction Heated Tandem System

The electrification of process heating through induction heating (IH) has gained attention due to the possibility of direct usage of renewable electricity replacing heating through fossil fuel combustion. We have previously shown that IH can decrease the reaction temperature by 30 ËšC and reduce the energy consumption by 67% through the design of the catalyst bed configuration, demonstrating its ability to improve production and energy efficiency. In this work, we applied IH to the ethanol-to-1,3-butadiene (ETB) reaction using Co as the susceptor to provide heat inside the reactor. 1,3-butadiene can be produced in two reaction steps through the Ostromislensky process. Our results show that the first step of ethanol-to-acetaldehyde over Cu/Al₂O₃ catalyst can be lowered to 215 ËšC with 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 in a tandem system can reduce energy consumption, produce fewer side products, and improve the selectivity to 1,3-butadiene. This can be achieved by applying IH as a targeted heating method; two temperature zones can be achieved in one reactor by controlling the amount of the susceptor.

Our results show that the tandem system can achieve 1,3-butadiene and butene isomers (C4 products) selectivities of 29.2% and 14.5%, while the selectivities are only 1.88% and 1.97%, respectively, over the ZrO₂/SiO₂ single catalyst bed with IH. The tandem system with IH improves the selectivity of C4 products by providing acetaldehyde as an intermediate to the second catalyst bed and controlling the temperatures separately for each reaction step. The selectivity of C4 products can be further improved by adjusting the reaction temperature, space velocity, bed configuration, and catalyst design. Our work has shown that the ethanol conversion of 62.9% and high C4 products’ selectivity of 55.3% can be achieved at nine times lower power consumption. We show that IH can individually control reaction temperatures in ETB reaction for the first time, which can be a breakthrough technology for reducing greenhouse gas emissions and increasing product efficiency.