A Study on Castor Oil and Its Conversion into Biodiesel by Transesterification Method

Abstract

Castor (Ricinus communis) beans were subjected for the extraction of oil which contained 48% yield. The refined oil contained 0.8% free fatty acid (FFA) and 76.258mg KOH/g saponification value which showed that oil was very suitable for biodiesel production. Biodiesel can be synthesized by transesterification process using acid or base catalyst. The obtained oil and biodiesel was analysed by GC/MS and characterized for its use as fuel in compression ignition motors. From GC/MS, methyl esters content (6:1 molar ratio) was found to be about 88%. The experiments were performed at variable condition such as methanol/oil molar ratio, different temperatures, types and concentration of catalysts used. The best condition for transesterification process was 9:1 methanol/oil molar ratio, 65°C and 1 weight % of KOH. Product analysis was performed by ASTM/EN standards. The obtained biodiesel provided satisfactory values of density and saponification but its viscosity was very high. This situation can be corrected by mixing other methyl esters or mineral diesel for its use as diesel fuel.DOI: http://dx.doi.org/10.3126/njst.v15i1.12009 Nepal Journal of Science and TechnologyVol. 15, No.1 (2014) 45-52