Reduced Graphene Oxide Functionalized with Sulfonic Groups as a Catalyst in the Production of Biodiesel Fuel Obtained from Recycled Cooking Oil

Biodiesel from recycled cooking oil was produced using reduced graphene oxide functionalized with sulfonic groups as a catalyst. The FTIR and Raman spectra of the catalyst showed indications of the presence of the sulfonic groups that were corroborated by EDS. The presence of acid groups of the catalyst contributed to a more efficient esterification, achieving a conversion of 70.9% compared to 63.2% without using a catalyst. In general, the properties of the biodiesel obtained presented acceptable values according to the ASTM D-6751 standard, such as an Inferior Calorific Value of 39,794 MJ/Kg, very close to the 42.7 MJ/Kg of conventional diesel. Therefore, the catalyst based on reduced graphene oxide functionalized with sulfonic groups is a viable option for the treatment of cooking oil, recycled to mitigate the contamination of city drainage, in the production of biodiesel suitable for use as fuel in diesel engines.