Integrating oxy-fuel combustion and power-to-gas in the cement industry: A process modeling and simulation study

The cement industry is one of the sectors responsible for the highest carbon dioxide (CO2) emissions of the world. CO2 capture technologies for storage and/or utilization are pointed out as the most relevant alternatives for significant greenhouse gases mitigation. Among CO2 capture technologies, oxy-fuel combustion has stood out due to its greater capture efficiency. For CO2 utilization, one alternative is to apply the power-to-gas technology. This study evaluated the CO2 capture and utilization for a cement industry employing oxy-fuel combustion and power-to-gas technologies. The integration of oxy-fuel combustion and power-to-gas technology was analyzed through the steady-state modeling and simulation of a cement plant using the commercial flowsheet simulation software Aspen Plus (R). Results show that despite the high demand for electricity, it is possible to use power-to-gas for the utilization of CO2 captured in the cement industry via the oxy-fuel process. To meet the oxy-fuel O2 requirements, it is necessary that 21.9% of CO2 be utilized. The electric energy consumption by the oxy-fuel and power-to-gas integration could range from 0,7 to 7,0 MWh/tclinker. However, values as high as 304.7 kgSNG/ tclinker could be produced, which would adhere to the standards required by Brazilian Law, assuming all captured CO2 was destined for utilization.