Inedible oil feedstocks for biodiesel production: A review of production technologies and physicochemical properties

• Published in: Sustainable chemistry and pharmacy 2022-12, Vol.30, p.100840, Article 100840
• Main Authors: Devarajan, Yuvarajan, Munuswamy, Dinesh Babu, Subbiah, Ganesan, Vellaiyan, Suresh, Nagappan, Beemkumar, Varuvel, Edwin Geo, Thangaraja, Jeyaseelan
• Format: Article
• Language: English
• Subjects: Inedible feedstock; Oil extraction; Physicochemical properties; Production technologies
• ISSN: 2352-5541; 2352-5541
• DOI: 10.1016/j.scp.2022.100840

Biodiesel emits lesser harmful pollutant emissions than renewable and biodegradable ones compared diesel. Research confirms that edible products and crops are the major sources of biofuel production. Excessive usage of these crops leads to higher production costs, economic imbalance, and depletion of food supply. Biofuel production from inedible sources shall lower the drawbacks of edible products and crops. Inedible feedstocks are the sustainable source of biofuel production as they are mostly grown on waste/abandoned land, produce similar or higher yields than edible feedstocks, and are fairly cost-effective. Hence this present work reviews the challenges and possibilities of employing inedible oil and products as a potential feedstock for biofuel production. Salient features of inedible oil such as production technologies, cost and benefits, fatty acid and physicochemical properties and oil extraction technology are reviewed from the latest literature. The outcome of this study suggests that there is a huge prospect of utilizing inedible oil as a reliable feedstock for biofuel generation. Among various production processes, scCO2 extraction technology proved to reduce inedible oil's moisture by 70% and FFA content by 62%, with a higher conversion rate of about 97%, as methanol in supercritical conditions has lesser interaction with the FFA of inedible oil. Inedible feedstocks are effective, non-toxic and safe in biofuel production. However, there exists a challenge in restricting its development in large-scale commercialization. [Display omitted] •Summary of the various feedstocks for biodiesel production is critically reviewed.•Production and extraction technologies of inedible oil are comprehensively discussed.•The physical properties of inedible oil were comprehensively studied.•ScCO2 extraction technology lowered the moisture and FFA content of inedible oil.•There is a huge prospect on utilizing inedible oil as feedstock for biofuel generation.