Valorization of furfural to fuel additives by aluminophosphate and metal-organic framework catalysts

Abstract

In this research, aluminophosphate (APAl) catalysts and metal oxide catalysts from calcined metal-organic frameworks (C-MOFs) were successfully synthesized. APAl-A catalysts were obtained from the FQM-383 laboratory group of Prof. Dr. Rafael Luque. The catalysts were named APAl-X/Y-A-Z which X/Y was the ratio of P/Al ratio and Z was the calcination temperature. Both factors were varied to study their effects on the catalyst properties of surface area and active acid sites on catalyst surface. The MOFs (MIL-101(Fe) and MIL-125(Ti)) were prepared by the solvothermal method. The calcination of MOFs (C-MIL-101(Fe) and C-MIL-125(Ti)) provided metal oxide catalysts. The APAl catalysts and C-MOFs catalysts catalyzed acetalization and hydrogenolysis, respectively. The furfural was used as the reactant in the reactions to upgrade the biomass and produce biofuel and chemical building blocks. The furfural acetalization with ethanol produced furfural diethyl acetal (FDA) which is biofuel. The acetalization reaction was studied in the batch system with varying reaction temperature to find the optimum condition. The reaction temperature of 25oC was found to favor the reaction. The APAl-85/15-A-773 exhibited the best performance in the reaction through the batch system with 89% conversion providing >99% selectivity of FDA. The catalyst reuse was investigated. Moreover, the furfural acetalization was estimated with the flow system over the APAl-85/15-A-773 giving 92% conversion. For furfural hydrogenolysis with 2-propanol, the furfuryl alcohol (FOL) was obtained. The FOL is an important starting material to produce other chemicals. The furfural hydrogenolysis with 2-propanol was studied through the flow system varying the catalysts. The C-MIL-125(Ti) catalyst showed the best performance in the reaction offering 83% conversion with 77% FOL selectivity.