An approach for enhancing optimal resource recovery from different classes of waste in South Africa: Selection of appropriate waste to energy technology

The need for effective municipal solid waste (MSW) management in an environmentally friendly, technologically viable, economically feasible and socially acceptable way presents a major global challenge. Planning of MSW management for municipalities require periodical evaluation of technology performance should consider the full waste hierarchy towards an enabling action for reduction, reusing and recycling in provision of energy and secondary raw materials for sustainable development. Decision support model is an integrated approach to enhance optimal resource recovery from different classes of waste for optimal economic importance, technical possibilities, environmental impact and sociocultural implication. The paper proposed a decision support model for selecting appropriate technology using approximation method for pairwise and normalized comparison matrix for Analytical Hierarchy Process (AHP) with subjective judgement of the sustainable indicators for different classes of waste in Western Cape municipality and six other urban areas. Among the four technologies, Anaerobic Digestion (AD) is ideal for the conversion of WtE with overall scoring of 57%, based on positive impact on the environment compared to Incineration (24%), Gasification (13%) and Pyrolysis (6%). The sustainable indicators criteria results revealed priority vector score for Environment as 0.4537, followed by Sociocultural at 0.2495, Economical at 0.2168 and Technical at 0.0800. The sensitivity coefficient for CR at 1 0,277 for technology and 0,238 for cost with preference to AD for the Western Cape Municipality in South Africa. This is important for policymakers in technology selection decisions support for MSWtE in similar contexts of the developing world.