Catalytic Conversion of 1,2-propanediol to 2-propanone: an Exploratory Study

Climate change underscores the urgency of exploring novel pathways for the decarbonization of the transportation sector. Within the aviation sector, biofuel appears to be the most viable short-term solution. Recently, the focus has centered on the aldol condensation of biomass-derived furans with ketones as 2-propanone (acetone) or 2-hydroxy-2-propanone (acetol), offering an efficient method to produce intermediates suitable for aviation fuels. However, 2-propanone is currently produced from cumene, a petroleum-derived source. This study proposes 1,2-propanediol (1,2-PDO), a sustainable product obtained by the hydrogenolysis of glycerol, a byproduct of the biodiesel industry, as a renewable feedstock for the generation of 2-propanone. For that purpose, the coprecipitation method with sodium hydroxide was employed to synthesize three copper, zinc, and aluminum-based catalysts. The catalysts were characterized through ICP-OES, N2 adsorption-desorption, XRD, and H2-TPR. The dehydration of 1,2-PDO to 2-propanone was investigated in a continuous system at 227 ºC, using a 10 wt% aqueous solution of 1,2-PDO at atmospheric pressure with a W/m ratio of 10 gCatalyst min g1,2-PDO-1. The catalyst with the lower zinc content achieved the highest carbon selectivity to 2-propanone at 22.1% and generated 1845 µmol2-propanone/mol1,2-PDO. This study revealed that lower zinc content could enhance 1,2-PDO dehydration to 2-propanone, preventing the subsequent hydrogenation of 2-propanone to 2-propanol. Additional optimization is required to attain higher yields.