Research Of The Influence Of Civil Stove Air Pollutants Based On Biomass Pellet Characteristics

Currently,winter heating in rural areas was one of the main sources of air pollution in China,so promoting the use of biomass pellet in those areas as cooking materials and heating method was an ideal way to reduce pollution,especially when it was combined with local conditions.By analyzing the effect of the properties of biomass pellet on pollution emission during the combustion,this paper has studied the combustion pollution emission and thermal performance indexes of different biomass pellet with different water content and different kinds,and with its mixture fuels.The main work contents were as follows:(1)Two biomass pellets,pear wood and elm wood,were selected to explore the emission factors of fuel water content on pollution emissions.The results showed that the emission factors of CO and PM2.5 gradually decreased in the low-power state during the combustion of pear wood fuel with the increase of water content.However,in the combustion of elm wood fuel,with the increase of water content,the emission factors of CO in the high-power state gradually decreased,while the emission factor of NOx in the two fuels,dried or increaed humidity,increased.In terms of thermal performance,the fuel water content had little influence on the thermal efficiency of biomass furnace and was not affected by the type of fuel.However,the higher the water content was,the longer the cooking boiling time was,and the combustion rate and cooking firepower intensity were obviously reduced.(2)The influence of a single fuel type on pollutant emissions from biomass stoves was analyzed.The results showed that the types of biomass pellet had strong correlation with the emission concentration of solid particles and gas pollutants.Due to the high content of N element in biomass fuel,NOx concentration emitted from combustion was generally high and the emission concentration range was between 73.7±12.5 mg/m3 and 610.4±71.2 mg/m3.At the same time,when a single biomass fuel was burned the negative correlations(r<-0.75)in a cooking and radiant heating stove and the same negative correlation in the water heating stove between O2 and SO2 and NOx,as well as CO2 and smoke temperature were verified through characterizations.(3)Blended biomass pellet was prepared from pine sawdust,corn straw,pine sawdust and jujube wood with the mass ratio of 7:3,5:5 and 3:7,and the influence on the performance of biomass stove was studied.The results showed that blended biomass pellet could reduce the emissions of NOx by 40%-65%and PM2.5 by 10%-15%,but the emission reduction effect was inconsistent at the high and low power combustion stage.The change of CO emission concentration was not obvious and mainly affected by the actual combustion condition.At the same time,when the blended biomass fuel was burned,the negative correlations(r<-0.53)in a water heating stove between O2 and SO2 and NOx,as well as CO2 and smoke temperature were verified more like the fuel with better pollution emissions through characterizations.