Thermal Behavior and Gas Emissions of Biomass and Industrial Wastes as Alternative Fuels in Cement Production: A TGA-DSC and TGA-MS Approach

Abstract

The cement industry contributes approximately 7% of global anthropogenic CO2 emissions, primarily through energy-intensive clinker production. This study evaluates the thermal behavior and gas emissions of seven waste materials (sawdust, pecan nutshell, wind blade waste, industrial hose waste, tire-derived fuel, plastic waste, and automotive shredder residue) as alternative fuels for cement manufacturing, motivated by the limited information available regarding their performance and environmental impact, with bituminous coal used as a reference. Thermogravimetric analysis and differential scanning calorimetry (TGA-DSC) were used to quantify mass loss and energy changes, while TGA coupled with mass spectrometry (TGA-MS) was used to identify volatile compounds released during thermal degradation. Both TGA-DSC and TGA-MS were conducted under oxidative conditions. The analysis revealed that these waste materials can generate up to 70% of coal’s energy, with combustion primarily occurring between 200 °C and 600 °C. The thermal profiles demonstrated that these materials can effectively replace fossil fuels without releasing harmful toxic gases like HCl, dioxins, or furans. Combustion predominantly emitted CO2 and H2O, with only trace volatile organic compounds such as C3H3 and COOH. The findings highlight the potential of alternative fuels to provide substantial energy for cement production while addressing waste management challenges and reducing the industry’s environmental impact through innovative resource valorization.