Sustainable contributions of the use of industrial and municipal wastes as an alternative fuel in cement plants – a review

Abstract One of the most appropriate methods of utilizing different types of waste is using these wastes as alternative fuels in cement factories and similar enterprises. In this paper, the impacts of the use of waste mixtures as alternative fuels in cement plants on process parameters, technological availability, costs, kiln design, quality of alternative fuels, calorific value, clinker quality, and the environment were reviewed based on the available literature. To contribute to the environmentally sensitive and feasible activities of cement enterprises and other stakeholders affected by waste, this study analyzed the sustainable contributions of using different waste mixtures as alternative fuels in cement factories through their combined processing. For this purpose, sustainability criteria for the use of wastes as alternative fuels were established, and the contribution of these waste mixtures to these criteria was determined. The literature reviewed supports the use of these wastes as alternative fuels in cement factories due to their environmental benefits, especially through waste, greenhouse gas, and fossil fuel reduction, as well as their benefits such as cost reduction and feasibility in enterprises in a sustainable scope. The results show that, compared to other waste groups, plastic waste, biomass waste, wood waste, tire waste, and wastewater sludge, in combination with other waste mixtures, provide more evidence of sustainability criteria. Furthermore, the evidence indicates that, compared to other criteria, the feasibility of using waste groups as alternative fuel is assessed by focusing on different percentages of mixtures, environmental remediation, the physical and chemical conditions of the waste and factors affecting its combustion, and the energy content of the waste. This study serves as a guide for investors, waste providers, municipal and industrial operators, all stakeholders affected by waste, countries, and policymakers targeting the use of alternative fuels in cement factories.