Facile synthesis and economic analysis of Cu/C catalyst for efficient biodiesel production

Abstract

A cheap biochar-based metal catalyst, Cu/C was prepared by employing a facile pyrolysis method and using the waste biomass resource of rice straw as C source, and was used in the transesterification reaction of soybean oil to prepare biodiesel. With the addition of copper nitrate and with a pyrolysis temperature of 400°C for the biomass precursor, the as-synthesized Cu/C-400 catalyst with a loading amount of 6 wt% in the reaction dispersion results in a biodiesel yield of 88.5% ± 1.8%. The Cu/C-400 catalyst still maintains a high activity with a biodiesel yield of 79.4% ± 1.2% after four cycles. The economic analysis about Cu/C-400 catalyzed production of 1 t biodiesel is carried out by using the life cycle cost (LCC) method, indicating that the cost of 1 t soybean biodiesel is about 7727.8 RMB. In particular, the catalyst cost is only 5.6% of the total cost, indicating the low cost of the synthesized catalyst. Finally, the sensitivity analysis reveals that an appropriate increase in catalyst loading amount can improve the biodiesel yield, but lead to an increase in the total cost of biodiesel, and therefore reasonable control of catalyst loading amount is necessary. This work will inspire the further development and application of biochar-based metal catalyst in biodiesel production.