A two-step strategy for the selective conversion of ethanol to propene and hydrogen

Abstract

Simultaneous production of propene and hydrogen from ethanol is a promising way of a renewable feedstock conversion into value-added products. Conventional reaction schemes of the direct one-step catalytic conversion of ethanol into propene include the reaction of the isopropanol dehydration to propene. However, the dehydration ability of a catalyst inevitably gives rise to the ethanol dehydration to ethene that diminishes the propene yield. To avoid ethanol dehydration to ethene, the two-step process is composed of the ethanol conversion to acetone in the first step and the acetone conversion to propene in the second step. The thermodynamic analysis of the known reaction pathways for the ethanol conversion to propene shows that a 74.6% yield of propene can be achieved even at a low temperature of 200 °C. According to the literature data, possible catalysts can be Cu/La2Zr2O7 or Fe3O4 for the first step, and the mixed Ag–In/SiO2 and K3PW12O40 catalyst for the second step. We speculate that the propene yield may reach 72% using these catalysts in the two-step process.