A comprehensive review on waste valorization of cashew nutshell liquid: Sustainable development and industrial applications
Sampson Kofi Kyei, William Iheanyi Eke, R. D. Nagre, Isaac Mensah, Onyewuchi Akaranta
Abstract
The idea of turning agro-wastes into industrial products through waste valorization is gaining popularity due to its significant role in a circular economy. This is of utmost significance in terms of the sustainability paradigm of resource utilization, contribution to the developing circular economy, and responsible consumption. Liquid extracts from cashew by-products are rich in phenolic compounds and are important for valorization and use as feedstocks in azo compounds/dyes; friction linings; surface coatings, adhesives, and varnishes; resins and rubbers; foundry chemicals; pesticides, larvicides, and anti-termites; pharmaceuticals; biodiesel production, and other applications. Hence, effective management of cashew by-products would result in a high-income generation and sustainable development. The review discusses issues that improve the utilization of cashew nutshell liquid for the attainment of some UN Sustainable Development Goals, explicitly SDGs 6 (clean water and sanitation), 9 (industry, innovation, and infrastructure) and 3 (good health and well-being). This comprehensive review will serve as a foundation for future research on cashew nut waste management and nanotechnological developments devoted to its use in green products that do not negatively impact the environment. Finally, it would mitigate the current issues and project the precise direction of potential opportunities and advancements for waste-derived CNSL.