Laboratory Quantification of Gaseous Emission from Alternative Fuel Combustion: Implications for Cement Industry Decarbonization.

The cement industry accounts for approximately 7% of global CO2 emissions, with fuel combustion contributing 40% of sectoral emissions. Alternative fuels from industrial and municipal waste offer emission reduction opportunities while addressing waste management challenges. This study quantifies real-time gaseous emissions (CO2, CO, NOx, and SO2) from seven alternative fuels-sawdust (SD), pecan nutshell (PNS), wind blade waste (WBW), industrial hose waste (IHW), tire-derived fuel (TDF), plastic waste (PW), and automotive shredder residue (ASR)-during calcination at 850 °C. Bituminous coal served as the reference fuel. Gas concentrations were continuously monitored using the testo 350 portable gas analyzer. Emission factors were calculated on a mass basis (kg/kg fuel) and energy basis (kg/GJ) for standardized comparisons. Alternative fuels consistently produced lower CO2 emission factors than coal, with biomass-derived fuels (SD and PNS) showing reductions of 45% and 38%, respectively. Most alternative fuels generated lower CO and NOx emissions per unit energy due to their higher volatile matter content, promoting complete combustion. TDF was an exception, exhibiting 2.8 times higher CO emissions. SO2 emissions were negligible except in the case of TDF (0.14% sulfur content). The measured emission factors were 15-30% lower than theoretical IPCC values, confirming the environmental viability of alternative fuels as coal substitutes in cement production.