Production of Biodiesel from Industrial Sludge: Recent Progress, Challenges, Perspective

Production of biofuels and their application in various industrial sectors along with transport vehicles greatly reduce the inevitability of fossil fuels. In addition to being non-renewable sources of energy, fossil fuels also have undesirable influence on the environment since they emit harmful gases. It has been reported in the available literature that the thermo-bio-chemical treatment of industrial sludge, agricultural and plant residues, microalgae, and sewage can contribute significantly to the manufacturing of biofuels like ethanol, bio-oil, syngas, hydrogen, and methane. A review of the literature also revealed that the most effective and appealing approach is to produce biofuels from industrial sludge that is readily available at no cost. The primary components of industrial sludge are detergents, phenols, lipids, proteins, and carbohydrates. Highly toxic pollutants including both inorganic and organic pollutants are also present in industrial sludge. The lipid component, made up of oils, greases, fats, and long-chain fatty acids resulting from industrial sludge, presents a great avenue for the production of biodiesel. It is widely acknowledged that the employed feedstock determines the majority of the costs associated with biodiesel production technology. As a result, it is crucial to convert the sludge into biofuels by inventing novel technologies to mitigate the energy demands in recent times as well as in the future. However, upscaling the industrial synthesis of biodiesel remains challenging. This chapter shall deal with the challenges associated with the production of biodiesel from industrial sludge and also shed light on future perspectives for developing novel techniques to upsurge biodiesel production.