Research On The Impact Of Carbon Emissions In The Industrial Silicon Production Proces

In the context of "carbon peaking and carbon neutral",the problems of high energy consumption and high emissions in the industrial silicon production process are particularly prominent.Based on a large amount of actual production data,this paper uses various methods to analyze the factors and degree influencing carbon emissions in the industrial silicon production process,with the aim of providing relatively scientific ideas for energy saving and emission reduction in this industry.The specific research content and results include the following three main articles:(1)Taking the actual factory data as the research object,the direct carbon emission and total carbon emission of industrial silicon production process were calculated by using activity level method and energy carbon emission coefficient.The total carbon emissions include direct carbon emissions from the consumption of carbon reducing agents,carbon emissions from the consumption of graphite electrodes in industrial processes and indirect carbon emissions from the consumption of electricity.A factor decomposition model of carbon emission in industrial silicon production process of 11 monthly stages was established by using logarithmic average Dirichter index decomposition method(LMDI method),which was divided into four factors: energy carbon emission coefficient,energy consumption structure,energy intensity and industrial silicon output.The results show that energy intensity is the biggest factor to curb carbon dioxide emissions,and energy consumption structure has a certain impact on reducing carbon emissions,but the effect is not obvious.The energy carbon emission coefficient has no effect on carbon emissions within a year,while industrial silicon production is the most influential factor that increases carbon dioxide emissions in every month of the year.(2)According to the carbon emission data calculated in(1),its average value and influence ratio are analyzed.The research results show that indirect carbon emission from power consumption is the main emission,followed by carbon emission from carbon reducing agent,and carbon emission from electrode is the lowest and most stable.The carbon emission of carbon reductants in industrial silicon production process in different types of mineral furnace was analyzed by statistics.It was found that raw material consumption was highly correlated with direct carbon emission and moderately correlated with total carbon emission.In8.5MVA furnace type,the order of influence degree of different carbon reducers on carbon emission is: bituminous coal > petroleum coke > wood block;12.5MVA furnace type: petroleum coke > bituminous coal > wood block.(3)The environmental impact of industrial silicon and its downstream high purity silicon production process is quantitatively calculated and evaluated by using life cycle assessment method.In the process of continuous purification of industrial silicon to obtain high purity crystal silicon by modified Siemens method,the main environmental impacts during the life cycle are divided into 1 to 10 impact categories by contribution analysis and improvement evaluation,and the weight of key factors determining environmental load is calculated.The results show that the combined environmental impacts of industrial silicon production and improved Siemens process to produce high-purity polysilicon are about 4.532 and4.991,respectively.According to the quantitative results,the emphasis of improvement is to reduce the power consumption in the production stage of high-purity silicon,and further optimize the waste recycling in the production process.