Challenges on waste-to-energy for the valorization of industrial wastes: Electricity, heat and cold, bioliquids and biofuels

Abstract

In light of legislative requirements and circular economy principles, valorization of wastes is the best strategy for its management. The biodegradable fraction of industrial wastes is a sustainable source of biomass, thereby optimizing its management by energy valorization, decreasing the quantity of waste that needs to be managed (and its economic costs), minimizing the environmental impact and health risks, and reducing the high dependence of industries on primary sources and fossil energy. Although traditional biomass sources, such as wood, crops, agricultural and forestry residues, and food and municipal wastes, are renewable, sustainable and cost-efficient, they compete with food and their energy processes release waste into the environment. Waste to Energy (WtE) is a recent, efficient and sustainable method of waste management based on the idea that energy sustainability involves both sustainable energy sources and sustainable energy systems. This paper reviews studies that propose industrial waste and by-products as sustainable, renewable and unlimited sources of biomass for use in sustainable energy systems to generate electricity, heat and cold, bioliquids and biofuels. The advantages and disadvantages of various types of resources are presented, and their limitations and the challenges that must be overcome are analyzed and compared.