| Traditional desulfurization denitration technology in secondary pollution,high water consumption,low ammonia escape,by-products utilization value of defects,Shandong university,based on the in situ preparation of powdered activated coke build coal-fired flue gas pollutants autonomy and high value utilization system in the process with coal itself on the combustion flue gas pollutants produced by sulfur recovery can be implemented at the same time,can help to alleviate the shortage of China’s sulfur resources status quo.Preliminary basic research and pilot test have carried out in-depth research on the system,but before further promotion and application,it is necessary to analyze the material energy consumption and environmental impact of the system,compared with the traditional flue gas pollutant treatment technology,analyze the advantages and disadvantages of the process.The operation characteristics of the autonomous and high-value utilization system of coalburning flue gas pollutants are analyzed,and the logistics model of the system is established.The system mainly includes in-situ preparation of powdery activated char,fluidization adsorption of SO2,thermal regeneration of sulfur-loaded activated char,directional reduction of SO2,catalytic reduction of NOx by pyrolysis gas.The in-situ preparation of powdery activated semi-coke refers to the rapid preparation of activated semi-coke and byproduct pyrolysis gas by pulverized coal in the flue gas environment,which is the most critical link in the whole process.Based on distributed activation energy model can predict the dynamic equations of coal pyrolysis products with Aspen plus logistics of coke making process simulation,and pilot tests to verify this model,this model can better predict when preparation conditions(temperature,O2 concentration and the concentration of water vapor in the atmosphere,CO2 concentration)changes,Production of reactive coke and pyrolysis gas(CO,H2,CO2 and CH4).The activated semi-coke prepared is used to adsorb SO2 in flue gas in a fluidized bed.When the activated semi-coke adsorbed SO2 is recycled and reused by thermal method,SO2 is desorbed,and then the activated coke/pyrolysis gas is coupled to be reduced to elemental S in the SO2-rich desorption,realizing the recovery of high elemental sulfur in flue gas.The pyrolysis gas can also be used as a reducing agent to catalyze the reduction of NOx based on the nitrogen oxide adsorption and reduction decoupling process.Based on the system logistics model established,the autonomous and high-value utilization system of 300MW class coal-fired flue gas pollutants is taken as the research object,and the material energy analysis is carried out from each process to the whole system,and the energy consumption of the system is analyzed combined with the three-link energy consumption model.The lignite energy conversion efficiency is 80.83%,and the energy conversion efficiency of the coking system is 62.73%.The fluidized adsorption process consumes 620.55kW of electricity,while the regeneration of sulfur-bearing coke and the reduction of SO2 consume 606.5kg/h of activated coke and 4775.43kW of electricity.The denitrification process consumes 630.3 1kg/h of activated coke and 558.13kW of electricity.The energy conversion efficiency and recovery efficiency of the system are 72.6%and 20.27%respectively.The key to improve the energy utilization efficiency of the system lies in the energy recovery link,and there is a large utilization space for cooling and discarding.In order to analyze the environmental performance of the system,based on the analysis of material energy consumption,the autonomous and high-value utilization system of 300MW class coal-fired flue gas pollutants and the representative traditional flue gas pollutant treatment system(wet desulphurization+ammonia SCR)were analyzed for the life cycle of the operation stage respectively.The annual energy consumption list,material consumption list and pollutant list are analyzed,and the environmental impact load can be compared.Considering the environmental impacts of greenhouse effect,acidification,eutrophication,photochemical ozone synthesis and soot and dust,the environmental impact load of the autonomous and highvalue utilization system of coal-burning flue gas pollutants is 6429.7PET2000 after weighting.The environmental impact load of wet desulfurization and ammonia SCR flue gas purification technology is 84670.89 PET2000.The environmental impact load of the autonomous and high-value utilization system of coal-burning flue gas pollutants is far less than that of wet desulphurization and ammonia SCR flue gas purification technology,which is a flue gas purification technology with less environmental impact. |
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