Valorization of used cooking oil: challenges, current developments, life cycle assessment and future prospects

Abstract

This review explores the recycling of used cooking oil, a global waste product with an annual production ranging from 41 to 67 million tons, for waste management and resource recovery. It examines the sources and composition of used cooking oil, focusing on its potential as a feedstock for valuable products. The review analyzes biochemical, thermal, and chemical conversion methods for their application in valorization of UCO (Used Cooking Oil). The advanced techniques such as catalytic upgrades, electrochemical conversion, membrane separation, and supercritical fluid extraction have also been investigated for their role in improving efficiency. Although biodiesel is the widely produced product, the review also sheds light on the recent researches for development of plastic, soap and other value-added products from UCO. Using a case study methodology and a review of recent research, the article also addresses challenges like feedstock variability and environmental impacts. It discusses market trends, regulatory frameworks, and potential research directions, aiming to integrate used cooking oil valorization into sustainable waste management and circular economy practices.