Investigating the environmental impacts of alternative fuel usage in cement production: a life cycle approach

Cement production is a complex process including the use of a high amount of raw materials and energy, and it causes significant emissions such as carbon dioxide and nitrogen oxide. However, the use of alternative fuels in cement production has ecological, economic, and social benefits. In this study, the environmental impacts of alternative fuel usage in cement production process were determined by life cycle assessment (LCA) using two methods: (1) IMPACT 2002+ for determining the effects on climate change, human health, ecosystem quality, and resources and (2) Hoekstra et al. (2012) for determining the effect on water scarcity. For this purpose, firstly, LCA of cement production was conducted for the present situation (PS) in Turkey. Secondly, three scenarios (S1, S2, and S3) were built which include different substitution rates (15% and 30%) and different alternative fuels (refuse-derived fuel [RDF] and thermally dried sludge [DS]). The results indicate that the use of RDF as an alternative fuel is more environmentally friendly than the use of DS in cement production. Climate change, one of the most significant impacts derived from cement production, reduces 27% and 12% with the 30% and 15% substitution rate of fossil fuel by RDF for all cement types, respectively. On the contrary, with the use of DS (substitution rate of 15%), climate change increases about 0.5% compared with PS conspicuously. Considering results in terms of water scarcity assessment, it is concluded that electricity consumption is the most significant process contributed to water scarcity because of the production process of electricity.