Utilisation of waste frying oil for the production of biodiesel.

Abstract

Given the rising energy demands and environmental concerns associated with fossil fuels, the conversion of waste oils into biodiesel presents a low cost and eco-friendly solution. The inappropriate disposal of Waste Frying Oil results in water treatment problems however, it can be used as a biodiesel feedstock contributing to a decrease in the environmental burden, besides replacing fossil diesel. This study focused on the production and characterization of biodiesel derived from waste cooking oil through the transesterification process. The project aimed to explore the viability of using readily available waste oils as an alternative feedstock for sustainable fuel production. The study involved characterization of the waste oil to determine its suitability as a feedstock to producing a good quality yield of biodiesel. Biodiesel was produced using the transesterification process which based on single step catalysis. The study investigated key parameters such as Fatty Acid Methyl Ester concentration, yield, viscosity, density and nitrogen content across varying methanol to oil ratios to evaluate the quality and performance of the resulting biodiesel. The obtained biodiesel was compared with the European and American standards to check whether it meets the required specifications of a biofuel. For waste oils whose acid value is 0.37%, results show that a methanol to oil ratio of 1:6 at a catalyst concentration of 1% wt gives the highest yield of methyl esters. Ratio 1:6 had the highest yield of 95% before washing and 89% after washing in terms of biodiesel output followed by 1:4 and lastly 1:8 implying that the methanol volumes should not be too low or too high to obtain a good quality yield of biodiesel. However, ratio 1:8 gives the cleanest biodiesel in relation to the nitrogen content which is a major impurity during combustion. The viscosity of the biodiesel across all ratios did not align with the acceptable ranges of the European (3.5-5.0) and American standards (1.9-6.0) because it was lower than the permissible values and more research on how to improve the viscosity of biodiesel as a fuel should be considered.