Integrating P2M-CC for Sustainable Decarbonization in Cement Manufacturing

The cement industry is recognized as an energy-intensive industry, and as a consequence of this, it is one of the industries that generate large amounts of CO2 into the environment. The global fight against climate change requires rethinking processes in such industries. The use of fossil fuels as a primary energy source and the cement production process make it one of the industries with the largest CO2 footprint. In this case, a sustainable solution, at least in the medium term, is to integrate the P2M-CC (Power - to - methane with carbon capture) concept, which involves replacing natural gas with synthetic methane obtained by methanization of green hydrogen and carbon dioxide captured from the industrial process. The paper analyzed three modernization scenarios of a cement plant with an annual production of 1,200,000 tons defined on the basis of techno-economic assumptions. It was observed that by integrating the P2M-CC concept in the initial process, the CO2 emission factor decreased from 789 (baseline scenario) to about 85 kg/ton of cement (proposed scenarios). From an economic point of view, the initial investment costs were significantly higher in the proposed scenarios than in the reference case due to the expansion of the plant by including electrolysis, methane, CO2 capture, and wind farm energy production. The costs were thus 5 to 13 times (€ 2.9 billion) higher than in the baseline scenario according to the assumptions underlying each scenario. In terms of operation and maintenance costs, the variation was totally different depending on the scenario analyzed, ranging from less than half of the costs of the baseline scenario to 2.4 times (€ 2.8 billion) higher. This variation depended to a large extent on the CO2 tax and the excess electricity used in the clinker process. The discounted cost per tonne of cement, LCOC, varied significantly for the 3 proposed scenarios, with the minimum value (about 58% lower than in the reference case) being obtained for the ideal scenario where the excess electricity covers the entire electricity needs of the cement plant processes. Despite the much higher initial investment and operating costs, the payback period was slightly longer than in the baseline case (5 vs. 3 years) due to the significantly higher net fees paid in the baseline scenario. In conclusion, the technical and economic improvement of the performance of the cement industry is dependent on the EU-wide regulation of CO2 taxes but also on the careful management of electricity generated by renewable energy sources.