Research progresses on oxy-fuel combustion carbon dioxide capture technologies in cement industry

ZHOU Yuegui; WANG Yuting; HUANG Guanshuo; CHEN Tao

doi:10.13226/j.issn.1006-6772.CBJ25022201

Abstract：Cement industry is one of the major industries with high energy consumption and high pollutants emissions,and its carbon dioxide(CO2)emission control has become a hotspot in the academia and industry.Oxy-fuel combustion technology is one of the most important technologies for high-efficiency and low-cost carbon dioxide capture,utilization and storage(CCUS)in cement industry,which is of great significance for reducing CO2 emission and enhancing cement clinker production.This paper systematically reviews the research progresses of oxygen-enriched combustion,partial oxy-fuel combustion and full oxy-fuel combustion in terms of experimental studies,numerical simulations,process optimization and industrial application.Oxygen-enriched combustion improves combustion temperature,heat efficiency and clinker production by increasing the oxygen volume fraction in the combustion air,and the optimal oxygen volume fraction is 27％-30％.It has been industrially applied in many cement production lines and has realized the fuel saving and yield enhancement.Partial oxy-fuel combustion is a CO2 capture technology with utilizing oxy-fuel combustion in the calciner,which can enhance CO2 volume fraction and reduce NOx emissions,but the calciner temperature needs to be raised appropriately in order to maintain the same calcination degree of limestone,and the fuel consumption will be increased.Full oxy-fuel combustion is used in both the calciner and rotary kiln,which can obtain a high CO2 volume fraction in flue gas,and it is the future direction of CO2 capture technology in cement industry.In order to achieve the same furnace temperature and product quality as those in air atmosphere,the overall oxygen volume fraction of full oxy-fuel combustion needs to be increased to 27％-29％,and it is also necessary to optimize the partitions of the oxygen volume fractions of primary/secondary/tertiary oxidizer streams both in the rotary kiln and the calciner oxy-fuel combustors.The techno-economic analysis of partial and full oxy-fuel combustion in cement industry shows that the CO2 capture cost is 200-250 yuan/ton,which is lower than that for post-combustion carbon capture technology,indicating that oxy-fuel combustion technology is better in the economic performance.In the future,the CO2 capture technology of oxy-fuel combustion in cement industry will be further developed in the direction of high efficiency,low cost and low energy consumption,focusing on research and development of the key technologies of full oxy-fuel combustion,low-cost oxygen generation technologies and deep integration with renewable energy power to gas and renewable synthetic fuels,in order to finally realize CCUS and net-zero CO2 emission in cement industry.