Under the background of global climate change, cement industry, as a traditional industry with high energy consumption and high emissions, is facing unprecedented challenges. In order to achieve green and low-carbon transformation, cement enterprises have sought various ways to reduce carbon. Wu Xiaomei, associate professor of
South China University of Technology, said that cement enterprises can reduce carbon from many aspects:
First, save energy and reduce consumption in the production process, do a good job in the management of equipment and technology upgrading, and reduce the level of power consumption and coal consumption in all links; The second is to reduce the proportion of clinker in cement within the scope permitted by national standards. The third is to use a large number of alternative fuels to reduce the consumption of fossil energy; Fourth, the extensive use of clean energy (solar, wind, hydrogen, etc.); Fifthly, the co-disposal of alternative raw materials (especially calcareous alternative raw materials) and solid hazardous wastes, a considerable part of the co-disposal projects of solid hazardous wastes are conducive to improving the burnability of cement raw materials and reducing the heat consumption of clinker; The six is CCS/CCCUS (carbon capture and collection technology).
"The use of alternative fuels can greatly reduce the consumption of fossil energy, thus reducing carbon emissions." Wu Xiaomei pointed out that at present, there are successful cases in the world that 100% of cement production lines use alternative fuels to produce cement, and the average proportion of alternative fuels in European cement enterprises has reached more than 60%. Taiwan Cement and other groups have done a good job in the application of alternative fuels.
A considerable number of enterprises, even under the condition that the old production line has not been enlarged in the second generation of dry kiln technology reform, through the use of alternative fuels, the standard coal consumption of clinker can reach the first level of energy consumption index , which not only achieves better social benefits and economic benefits in carbon trading in reducing carbon emissions, but also improves the economy. Moreover, the price difference between coal and alternative fuels also brings direct and considerable economic benefits to enterprises.
However, there are also some difficulties in the practical application of alternative fuels, such as the unstable grade of alternative fuels (moisture, calorific value, particle size, combustion rate); The transportation and metering of alternative fuels are unstable ; the bottleneck of the amount of substitution is affected by the burning speed/space and the limit of harmful components (such as chloride ions), and is restricted by the output or quality of clinker. "These factors will affect the actual carbon reduction effect of alternative fuels." Wu Xiaomei said.
According to Wu Xiaomei, because there are many kinds of alternative fuels used by enterprises and the quality changes greatly, the harmful components or trace components brought by alternative fuels are different, and the impact on the quality of clinker is also different. This problem needs to be analyzed on a case-by-case basis.
But in general, if the alternative fuel is mainly domestic waste or general industrial combustible waste, when the substitution ratio is high, it may bring more alkali content to the clinker, thus causing the 28-day strength of the clinker to decrease. Because the calorific value, combustion rate and feeding rate of alternative fuels fluctuate greatly, the output and quality of clinker will also increase.
How to reduce the impact of alternative fuels on clinker production and quality? What problems should cement enterprises pay attention to when using alternative fuels? On October 24-25, China Cement Network will hold the "2024 China Cement Double Carbon Conference and the 12th Energy Conservation and Environmental Protection Technology Exchange Conference" in Wuhu Conch International Hotel. At the meeting, Wu Xiaomei will bring wonderful sharing, please look forward to it!
