Biodiesel Production from Municipal Wastewater Sludge Recent Trends

Municipal wastewater treatment plants produce huge amounts of sludge, which is expected to increase with the advancement of modern society. Sludge management is expensive and challenging for any wastewater treatment plant. Different approaches are being considered to reduce waste management cost and to produce valuable fuels and chemicals. As municipal sewage sludge is a good source of lipids and phospholipids, it is a potential source for biodiesel (‘fatty acid alkyl ester’) production. Biodiesel, a key alternative of petrodiesel, is produced via esterification and transesterification. It receives huge attention as it is renewable and environmentally viable and can be used either directly as a fuel or as a blend with petrodiesel without any engine modification. But biodiesel production is not economically viable mainly due to the higher raw material cost and edible sources that compete with food materials. Hence, it is important to find an alternative, inexpensive, and readily available raw material source. Sewage sludge can play a vital role in biodiesel production to mitigate the production cost and environmental footprint. Biodiesel production from wastewater sludge has been widely investigated over the last two decades. This chapter highlights the recent advances, challenges, and economic analysis of biodiesel production from municipal sewage sludge.