Physico-chemical analysis of biodiesel obtained from blends of virgin castor oil and biodiesel obtained from mixture of oil

Abstract

Castor oil is one of the most important potential feedstocks for biodiesel production, but the product obtained has problems within the specific density and viscosity specifications. A wat to improve these properties is to produce biodiesel form blends of castor biodiesel oil with other biodiesel oils. On the other hand, the recycling of waste oils and fats to obtain biodiesel can help in the economic development of several regions in Brazil. This work includes producing biodiesel from blends of virgin castor oil and waste frying oil. Biodiesel production from blends of virgin castor oil (VCO) and waste cooking oil (WCO) from ethylic route and alkaline catalysis was studied in this work. Physico-chemical characterization of VCO (B1), WCO (B2) and three different blends (B3: 50%VCO + 50%WCO; B4: 25%VCO + 75%WCO; B5: 75%VCO + 25%WCO) were evaluated. Initial blend was characterized by acidity level, free fatty acid, saponification index, and density. Iodine and cetane index, glycerin, absence of triglycerides and rheological behavior were determined for obtained biodiesel. The results indicated that the acidity level dropped considerably after the transesterification, however only biodiesel from B1, B4 and B5 showed acidity index in accordance with the standard parameters. Nevertheless, B1 viscosity and cetane number lied outside the legislation. All samples were within the specified standard for iodine index and density. Despite the fact that B4 and B5 results were within the legislation for biodiesel, B4 would be a better alternative due to higher quantity of WCO.