WANG Junjie;YANG Huawei;ZHAN Yueping;CHAI Zhen;CAI Jun;ZHU Zhiping;State Key Laboratory of Coal Conversion,Institute of Engineering Thermophysics,Chinese Academy of Sciences;Shanxi Key Laboratory of Coal Flexible Combustion and Thermal Conversion;Shanxi Engineering Research Center of Coal Clean,Efficient Combustion and Gasification;University of Chinese Academy of Sciences;The cement industry is an important basic raw material industry, and also an industry with high energy consumption and high carbon emissions. China has abundant biomass resources. As alternative fuel, the application of biomass in the cement industry can help reduce the fossil energy consumption and carbon emissions, which is one of the main ways to achieve carbon neutrality for China′s cement industry. Progress and existing problems for biomass to be applied in the cement industry was analyzed, and solutions were gave. Compared with traditional fossil fuels, biomass fuel has such characteristics as high moisture content, low calorific value and large size. When it is used in cement production, these problems such as lower fuel burnout rate, higher flue gas volume, higher heat consumption, higher alkali content and larger fluctuation might be caused. A series of standards on solid recovered fuel(SRF) have been established abroad, laying a foundation for the standardized preparation and large-scale use of SRF including biomass in cement industry. According to the dataissued by the Global Cement and Concrete Association, the proportion of biomass fuel in the global cement industry accounted for 6.7% in 2020, among which agricultural, organic, diaper waste accounted for the largest proportion, i.e., 32%. The biomass fuel in Czech Republic, Germany, and Poland accounted for more than 22%. In contrast, the use of biomass and other alternative fuels in China′s cement industry started late. By 2021, the proportion of cement production lines using alternative fuels was less than 3%, and the thermal substitution ratio was about 2%. From the perspective of domestic application, biomass as alternative fuel can help reduce fossil fuel consumption, but there are still some problems such as incompatibility with the existing thermal system, low efficiency of thermal utilization, and certain influence on the production and quality of clinker. In order to reduce the negative impact of biomass fuel, it is necessary to pretreat it. Therefore, relevant technologies including mechanical pretreatment and high-temperature combustion pretreatment were introduced, and their advantages and disadvantages were compared. At the end of the paper, the main problems on the application of biomass fuels in cement industry were analyzed and the corresponding solutions were put forward. The solutions are to strengthen the pilot study and enhance its guidance to the actual production, improve relevant standards and establish an industry chain of alternative fuels including biomass, use the large amount of low-temperature waste gas from cement kiln to dry biomass fuel and reduce the water brought into the system, optimize the relative positions of biomass fuel fed to calciner by CFD simulation, popularize the high temperature combustion pretreatment technology such as circulating fluidized bed per to the type of biomass fuels, develop intelligent control system for alternative fuels and reduce the impact on clinker production quality. The cement industry is an important battleground for China′s carbon emission reduction. Biomass as alternative fuel will certainly show strong vitality and broad application prospects in the cement industry, and make important contributions to the realization of China′s dual-carbon strategic objectives.
2023 10 v.29;No.158 [Abstract][OnlineView][HTML全文][Download 16836K]