Biodiesel production from waste shortening oil from instant noodle factories

Waste shortening oil (WSO) from instant noodle factories was used for biodiesel production by transesterification using alkali as a catalyst in a laboratory scale. The effects of various parameters such as potassium hydroxide concentration, methanol/WSO molar ratio, temperature and reaction time on the biodiesel production were investigated. To determine the optimal operating condition for biodiesel production, potassium hydroxide concentration from 0.25 to 1.5 wt%, methanol/WSO molar ratio from 3:1 to 9:1, temperature from 35 to 65 °C and reaction time from 30 to 90 min were employed. The highest ester yield of biodiesel was obtained at the catalyst concentration of 1.0 wt% KOH, methanol/WSO molar ratio of 8:1, temperature of 55 °C, and reaction time of 60 min. Biodiesel obtained had many advantages such as high cetane number, low acid value and carbon residue and can be used as an alternative diesel without modifications to engine or injection system.