Production of biodiesel from low-quality vegetable oils with a high content of free fatty acids by acid-catalyzed transesterification

Univesity of Ruse “Angel Kanchev”, Department of Repairing, Reliability, Mechanisms, Machines, Logistic and Chemical Technologies, Agrarian and Industrial Faculty, 7017 Ruse, Bulgaria

^* Corresponding author: vkopchev@uni-ruse.bg

Abstract

Research on the production and application of cheap and renewable energy sources is one of the most relevant directions in modern science. They are imposed for a number of reasons, mainly due to the limited deposits of oil, natural gas and coal, the protection of the environment and the health of people. Unfortunately, the needs for such alternative energy sources are huge, and the possibilities for obtaining them are limited. On the other hand, low-quality vegetable oils obtained as waste products or as a result of improper storage or processing, as well as oils after use represent a valuable raw material and energy source. However, this necessitates the search for ways to utilize them by turning them into better quality products. The aim of the present work is to investigate the possibility of obtaining methyl esters of fatty acids (biodiesel), from vegetable oils with high acid values, by transesterification with acid catalysts, which includes the selection of suitable catalysts and conditions for optimal process progress.