Study On Combustion Characteristics And Particulate Pollutant Emission Of Coal-Biomass Briquette

China’s energy structure is dominated by coal.More than 80%of the coal is used for direct combustion every year,resulting in a large amount of energy waste.Meanwhile,as a big agricultural country,China is rich in biomass energy.As a kind of renewable energy,biomass energy has a broad prospect.The direct burning of crop straws in situ also brings serious environmental pollution and energy waste.Biomass briquette technology is an important clean coal technology,which can bring huge environmental and economic benefits.In this paper,Zhaotong lignite,Shenhua bituminous coal and Jincheng anthracite were selected as raw materials.Starch solution and polyvinyl alcohol were used as binder to compress coal and corn stalks with different degrees of coalification into briquette under the pressure of 25MPa.The combustion characteristics of biomass briquette were studied by thermogravimetric analyzer.The effects of biomass content,degree of coalification and combustion atmosphere on combustion characteristics were discussed.The kinetic parameters under different conditions were calculated.The emission rule of PM_2.5 fine particulate matter in the flue gas of coal-biomass briquette furnace was summarized.The experimental results show that the addition of biomass reduces the ignition point of coal and effectively improves the combustion performance of raw coal.When the biomass content is 5%,10%,15%,20%,25%and 30%,the comprehensive characteristic combustion index of lignite is 2.89,4.46,5.07,6.73,8.76 and 13.16,respectively.The higher the biomass content,the better the combustion characteristics of biomass briquette.When the biomass content is 20%,the comprehensive combustion characteristic index of bituminous coal,lignite and anthracite is 9.9,10.5and 2.3,respectively.The comprehensive characteristic combustion index of bituminous briquette is better than that of lignite and anthracite.When the biomass content is 10%,the characteristic index of bituminous coal pyrolysis and combustion is 0.8 and 1.2.When the biomass content is 20%,the comprehensive characteristic index of bituminous coal pyrolysis and combustion is 1.5 and 1.8.When the hybrid biomass briquette is burned in civil furnace,with the increase of biomass content,the emission factor of PM2.5 fine particulate matter,the emission factor of PAHs and the emission factor of heavy metal have the same law.When the biomass content is 15%,the emission factor of pollutants is the minimum.The emission factor of anthracite is much smaller than that of lignite and bituminous coal.There are 18 figures,22 tables and 75 references in this dissertation.