Synthesis of Biodiesel from Ricinus communis Oil Using Acid and Base Catalysts: Experimental Insights

Abstract

The escalating global demand for petroleum products has led to a consistent rise in the prices of conventional fuels such as petrol and diesel. With fossil fuel reserves depleting at an accelerated pace, it is anticipated that by 2025, the world may encounter a critical shortage of petroleum-based energy sources. Consequently, there is an urgent need to explore and develop sustainable alternatives to fossil fuels. Among the various renewable energy options, biodiesel has emerged as a viable and environmentally benign substitute. Biodiesel is defined as the mono-alkyl esters of long-chain fatty acids derived from vegetable oils or animal fats. It is characterized by favorable attributes such as biodegradability, non-toxicity, and negligible sulfur and aromatic content, making it a cleaner-burning fuel.

In the present study, a detailed experimental investigation was conducted to synthesize methyl esters from non-edible feedstocks, specifically castor oil, utilizing acid (H₂SO₄) and base (NaOH) catalysts. The influence of key process parameters such as reaction temperature and residence time on the biodiesel yield and physicochemical properties (including viscosity, specific gravity, and acid value) was systematically evaluated. The comparative analysis of acid- and base-catalyzed transesterification processes revealed significant differences in performance and product characteristics, thereby contributing valuable insights into catalyst selection and process optimization for biodiesel production.