Process Optimization of Catalyst Removal and Characterization of Waste Water After Alkali-Catalyzed Transesterification of Jatropha Oil

Abstract

Raw jatropha oil was transesterified in the presence of different alkaline catalyst solutions. A solution of 3-wt% KOH with methyl alcohol was found to be optimum for producing ester with lowest viscosity. Methyl alcohol was also found to be more effective over ethyl alcohol for converting raw oil to corresponding esters. After separation of the glycerol layer from ester under room temperature, three consecutive washings were carried out using single distilled water in the ratio of 5 to remove catalyst from the produced ester. Nearly 75% catalyst removal from ester was recorded within 30 min of contact period. Among the chemical characteristics of the waste water, its pH, chemical oxygen demand, and concentrations of oil and grease, and phenol were measured. Waste water was found to be alkaline in nature, and its chemical oxygen demand ranged from 684 to 792 mg/l. The phenol concentration varied between 103 and 163 mg/l, while oil and grease concentration ranged from 1433 to 1640 mg/l, representing a significant pollutant load in biodiesel waste water.

Keywords:

• COD
• Jatropha oil
• Oil & grease
• Phenol
• Waste water