Evaluating recent developments in utilizing organic waste for biofuel production - A comprehensive review

Abstract

Energy is the primary need for carrying out various activities. With limited resources, depleting energy source materials, and rising demand, alternative sources for energy transformation are explored. Waste materials discarded after their primary use have the potential for energy generation. Solid waste, especially organic waste, has a high degradability rate due to its rich microbial population. During the degradation process, it produces biogas, which can be utilized as an energy source. This review evaluates the viability and sustainability of waste-to-energy technologies by incorporating thorough techno-economic and environmental analysis. Anaerobic Digestion (AD), aimed primarily at biogas production, utilizes a diverse microbial community in oxygen-free conditions. A higher abundance of particular bacteria, such as Firmicutes and Bacteroidetes, helps to maintain the reactor's stability. The degradation rate has been modelled with different mathematical equations, and the modified Gompertz model is found to be most suitable for AD. The positive impact of advanced tools like artificial intelligence, machine learning, and life cycle assessment on conventional technologies can help the research community to improve the design and efficiency of waste-to-energy technologies. Regardless of the advancements in co-substrate degradation, the utilization of catalysts and carbon-rich additives for faster degradation or the use of nanomaterials and bioplastic for increasing gas yield, biogas production as a profitable business model is still a challenging task due to variability in feedstock, technical limitations in handling bulk waste, impurity in final output gas, and contaminated by-product formation. © 2025 Elsevier B.V., All rights reserved.