Sugarcane wastes into commercial products: Processing methods, production optimization and challenges

Sugarcane is a cash crop that has been a significant source of revenue in many countries around the world. In the last few decades, sugarcane mills that were only intended for sugar production were converted into biorefineries. Biorefinery enables the co-production of useful products from the sugarcane wastes such as bagasse, molasses, cane trash, filter mud and vinasse. In certain applications like disposable plates, fly ash, and as reinforcement in polymer composites, bagasse can be directly employed without the need for secondary processing while applications like paper, biochemical, lignosulfonate, vanillin, etc., require secondary processing through the biochemical route involving pre-treatment, acid hydrolysis, and fermentation. Other sugarcane wastes can also be mixed with bagasse to obtain biomethane, bioethanol, and bioelectricity. This article focuses on the recent advancements in such pre-treatment and processing methods employed by the researchers. It also outlines the strategies to co-generate two different products and ways to maximize the product yield and highlights various parameters influencing the process. The challenges that are critical to the sustainability of the sugarcane biorefineries and their mitigations were also discussed.