Economic, environmental and exergy analysis of the decarbonisation of cement production cycle

The aim of this study is to analyze the exergetic, environmental, and economic impact of the use of alternative fuels (Plasmix), instead of coal on the clinker production to valorise a non-recyclable waste and to limit global CO2 emissions. The cement production process was implemented in AspenPlus® environment, simulating different scenarios with the possibility to conduct the non recyclable plastic waste incineration in oxy-combustion conditions. Three scenarios were considered: without and with flue gas recirculation from the pre-heating tower and the oxy-combustion layout. Sensitive analyses were carried out to optimize cyclonic pre-heater tower working. Exergetic and economic analyses were performed, and the relevant impacts on economic profitability were analysed. The study reports the advantages and disadvantages of the different scenarios in terms of exergy efficiency, energy requirements, economic impact and pollutants emissions savings. Oxy-combustion layout resulted in 18.4% savings in terms of CO2 emissions but, at the same time, a lower Return of Investment (11.79%) with respect to the scenario with flue gas recirculation (11.82%). The exergy analysis of third scenario re returned the maximum obtainable value of the exergy efficiency (58.4%).