Abstract:Against the backdrop of "dual carbon", replacing traditional fossil fuels with green energy has become a key measure for carbon emission reduction at the source in the cement industry. Therefore, this study takes a 2 500 t/d cement clinker production line as the research object, analyzes the effects of different substitution ratios of hydrogen and ammonia on the flue gas flow, composition and temperature at the outlet of the decomposition furnace through thermodynamic analysis, and conducts an economic analysis. The results show that the blending of hydrogen in the decomposition furnace reduces the mass flow of the outlet flue gas, slightly increases the volume flow, raises the outlet temperature, increases the volume fractions of O2 and H2O, and reduces the volume fraction of CO2. The blending of ammonia in the decomposition furnace increases the mass flow of the outlet flue gas, decreases the outlet temperature, increases the volume flow more than that of hydrogen blending, increases the volume fractions of O2 and H2O, and reduces the volume fraction of CO2. The economic analysis shows that when the costs of green hydrogen and ammonia decrease to 5 320 CNY/t and 792 CNY/t respectively, or when the carbon tax prices rise to 2 773 CNY/t and 2 858 CNY/t respectively, the costs of using green hydrogen/ammonia in the cement industry will be comparable to those of coal. This study can provide important references for future energy conservation, emission reduction and energy structure optimization in the cement industry.