Environmental Impact Assessment of Using Waste Tires as an Alternative Fuel in a Cement Clinker Production Plant in...

Waste tires as an alternative fuel in the cement industry offer multiple advantages, including reduced CO₂ emissions and decreased reliance on fossil fuels. In this study, a comparative life cycle assessment (LCA) was conducted for cement clinker production with coal (CPC) as fuel and with waste tires as an alternative fuel (CPCT). The study adopted a "gate-to-gate" scope, with a functional unit of 1 ton of clinker. Environmental impacts were evaluated using the IMPACT 2002 + method. Global warming and non-renewable energy were the dominant impacts in cement clinker production. Compared to the CPC scenario, the CPCT scenario reduced the endpoint damage to resources, climate change, and human health by 19.91%, 2.30%, and 0.70%, respectively. However, the damage to ecosystem quality increased by 11.53%. When the waste tires substitution ratio increased from 5% to 20% according to scenario simulation results, the impacts on non-renewable energy and global warming dropped by 16.23% and 8.59%, respectively. Conversely, this higher substitution ratio exacerbated terrestrial acid/nutri (+10.75%), aquatic acidification (+9.70%), and respiratory inorganics (+5.76%). The results indicated a trend toward reduced reliance on coal and lower CO₂ emissions in the cement clinker production process through the substitution of waste tires. Nevertheless, the trade-off involved higher emissions of certain pollutants, most notably NO_x, leading to increased ecosystem-related impacts.