【Frontiers in HaiChuan Chemical Technology】Dalian Institute of Chemical Physics develops technology for using steel waste as a catalyst in cement production

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The Dalian Institute of Chemical Physics has developed a technology for using steel waste as a catalyst in cement production. Recently, research teams led by Researcher Lu Fang from the Biomass Hydrogen Bond Selection and Activation Research Group (DNL0605) in the Bioenergy Research Department, Researcher Cai Rui from the Low-Carbon Strategy Research Center (DNL26), and Academician Liu Zhongmin from the Low-Carbon Catalysis and Engineering Research Department (DNL12) at the Dalian Institute of Chemical Physics, in collaboration with partners such as the China National Building Materials Research Institute and Northeastern University, have made new progress in achieving low-carbon production in the cement industry. The research team utilized the iron components present in cement raw materials to create a catalytic system that mimicked the composition of steel waste, thereby producing iron-based catalysts. These catalysts enabled the selective conversion of calcium carbonate (CaCO3) and methane (CH4) into calcium oxide (CaO) and syngas (CO and H2) when heated together. Such catalysts can be used directly in the production of cement clinker without the need for separation, offering a new pathway for the green and low-carbon transformation of the cement industry. The carbon emissions from the cement industry account for about 7.5% of global industrial carbon emissions, with the decomposition of carbonates accounting for 60% of the carbon emissions generated during cement production. Due to the dual constraints of thermodynamics and kinetics in the carbonate decomposition process, it has been impossible to overcome the technical barrier of forced decomposition at high temperatures. Currently, the main strategies for reducing carbon emissions in the cement industry include improving equipment efficiency and using low-carbon alternative fuels such as biomass and hydrogen. However, none of these methods alter the core chemical process of calcium carbonate decomposition, making it difficult to address the high carbon emission issues in the cement sector on a fundamental level. In this study, researchers used metal elements such as iron, aluminum, and zinc to simulate the composition of steel waste and prepare catalysts. These catalysts were used to facilitate a co-thermal conversion reaction between CaCO3 and CH4 in a methane atmosphere; after the reaction, the catalysts did not need to be separated and could be used directly in the production of cement clinker, while simultaneously producing syngas with high added value. Experimental results show that, compared to traditional carbonate decomposition processes, this method can reduce carbon emissions by approximately 80%, offering a new pathway for deep decarbonization in the cement industry. Mechanistic studies indicate that this catalytic process occurs primarily through two pathways: the direct reaction pathway involves the interaction of adsorbed CH4 with the carbon-oxygen bonds at the Ca-Fe interface, resulting in the formation of CO and H2 ； The decomposition-absorption pathway involves CaCO3 first decomposing to form CaO and CO2, which then react with activated CH4 to produce CO and H2. Experiments show that the direct reaction pathway is dominant. Furthermore, the research team used iron oxides as active sites; by introducing aluminum and zinc, they increased the specific surface area of the catalyst as well as the dispersion of the catalytic active sites, thereby optimizing the microenvironment around the iron sites and enhancing the catalyst’s activity. Life cycle assessment (LCA) shows that this technology has good environmental benefits and potential for carbon emission reduction. The relevant findings were published in *National Science Review* under the title “Carbon emission reduction in cement production catalyzed by steel solid waste”. The co-first authors of this work are Engineer Liu Zhenggang and Associate Researcher Lu Rui from Group DNL0605 in my institute. This work was supported by projects such as the **National Natural Science Foundation and the Liaoning Binhai Laboratory.