Review of biodiesel production by the esterification of wastewater containing fats oils and grease (FOGs)

• Literature review on the esterification/transesterification catalytic processes in biodiesel production. Highlighting use of Fats, Oils, and Greases (FOGs) from wastewater. Reduction high Free Fatty Acid (FFA) content FOGs by esterification to methyl/ethyl ester. Evaluation reaction conditions, such as temperature, time, types catalyst, alcohol. A promising solution for near future is substitution non-renewable fossil fuels with a sustainable liquid feedstock biofuel (biodiesel) The cost conventional production higher than that petroleum-based diesel since it produced mostly expensive high-quality virgin oil. 70–80% overall associated raw materials. Brown grease (with free fatty acid levels > 15%) created rendered trap waste known (FOGs). It potential source feedstocks available at no cost. Many researchers are interested using low-cost oils This paper reviews effect pre-treatment process parameters conversion FOGs-wastewater esterification, including alcohol oil molar ratio, catalyst amount.