Sustainability challenges in conventional shea butter production in Africa: a review of energy consumption and resource efficiency

This paper addresses the energy consumption in conventional shea butter production processes and its impact on sustainability. The socio-cultural significance of shea butter extraction and the environmental challenges posed by the demand for firewood in the Shea belt are considered. The aim of this study is to review the existing research on energy consumption in conventional shea butter production processes and provide insights into reducing energy consumption while improving sustainability. The specific objectives are to analyse critical operations in the process and quantify their electricity, water, and heat demand. The study identifies grinding shea kernels into a paste, fat recovery, and oil clarification as the key operations regarding electricity, water, and heat demand, respectively. The conventional production process heavily relies on firewood as an energy source, consuming approximately 8–10 kWh of heat per kg of produced crude shea butter when improved cookstoves/roasters are used. However, the use of three-stone cookstoves can double or even quadruple the heat demand. Valorisation of shea butter process residues, such as kneading sludges, has the potential to cover 50% of the required heat and replace significant amounts of firewood. However, this approach necessitates careful process design and potentially alternative fuels from the residues to ensure efficient combustion and reduce smoke emissions. The conventional shea industry generates a considerable amount of by-products, yet no systematic and efficient valorisation scheme is currently implemented. By implementing improved cookstoves and developing a comprehensive valorisation strategy for process residues, significant reductions in energy consumption and environmental impact can be achieved.