Bioethanol Production from Crop Waste: Sustainable practice for agro-waste management

With the increasing global energy demand, alternative renewable energy sources with sustainability are being explored. One of them being production of bioethanol. Huge quantities of agricultural lignocellulosic wastes are generated worldwide which are usually combusted in the open atmosphere, leading to air pollution and the release of greenhouse gases. These gases eventually cause global warming. Microbial valorization of such types of agricultural lignocellulosic waste materials, e.g., bioethanol production, is one of the most environmentally friendly alternatives for agro-waste management and biofuel production. Bioethanol is a potential renewable fuel since it is combusted more cleanly and results in less greenhouse gas emissions. Yet, recalcitrance of lignocellulosic biomass, mostly lignin, cellulose, and hemicellulose, presents substantial barriers to its conversion. To mitigate this problem, efficient pretreatment methods are needed to eliminate lignin and hemicellulose, supplemented by enzymatic hydrolysis and fermentation of released sugars. Integrated pretreatment strategies, along with the use of efficient enzyme-producing microbes, create avenues for enhancing the commercial viability of bioethanol. This review focuses on the production process of bioethanol from agricultural waste, its limitations, applications, and future perspectives.