Production of biodiesel from dairy wastewater sludge: A laboratory and pilot scale study

This study investigates the production of biodiesel from activated sludge of milk processing plant as a low cost feedstock. The method involves lipid extraction, refining and optimization of biodiesel from activated sludge under laboratory conditions. These results were scaled up to a pilot plant was analyzed. In the laboratory study, the sludge yielded 18.81 wt% of crude lipid. It is degummed and dewaxed to get refined oil that is used for the production of biodiesel. The optimal reaction parameters were 0.8 wt% catalyst; a temperature of 55 °C; 6:1 methanol to oil molar ratio for 40 min. The process is scaled up to a prototype demonstration plant with a batch size of 10 kg. The dried sludge yielded 16.2 ± 1.3 wt% and 13.64 ± 0.8 wt% of crude lipid and biodiesel respectively. Biodiesel made in pilot plant is compared with ASTM standards. Keywords: Activated sludge, Extraction, Biodiesel, Scale u