The Study On Ash Melting Characteristic And Pore Structure Of Blend Ash Of Degreased Kitchen Waste And Straw Biomass

About 60 million tons of kitchen waste is produced every year in China,which is a major component of urban domestic waste.The kitchen waste contains a large amount of combustible ingredients.By burning,it can not only turn waste into treasure to solve the energy crisis,but also reduce and recycle waste.Due to the low calorific value of the kitchen waste,the pre-treated Degreased Kitchen Waste(KW)and straw waste are mixed and burned,which not only can use straw waste,but also can improve the burning quality.In this paper,the melting characteristics and pore structure of mixed ash samples of KW and straw biomass were studied in order to provide reference for boiler KW and its slagging biomass.The main research results are as follows:(1)Elemental analysis and industrial analysis were used to determine KW and three types of straw-like biomass(Rice Straw(RS),Corn Straw(CS),Wheat Straw(WS))The composition and the ash melting point tester and XRD experiments were used to analyze the effects of different process conditions(mixing type,blending ratio,ashing temperature)on the ash-like melting characteristics of KW and biomass at 800? ashing temperature.All three biomasses can reduce the melting temperature of mixed ash samples.The main reason for the decrease of melting temperature of CS and KW and RS and KW mixed ash samples is the decrease of mullite and sillimanite content until disappearance and the increase of leucite content;The decrease in the content of sillimanite and the increase in the content of leucite and albite are the main reasons for the decrease in the melting temperature of the mixed ash and KW samples(2)With the increase of ashing temperature,the ash melting temperature of KW,WS and its mixture decreases continuously.With the increase of ashing temperature,KW ash is mainly composed of quartz and anorthite,and also Contains a small amount of mullite and sillimanite;WS ash is mainly quartz,and when the temperature is low,there will be Na salt and K salt.When the temperature is high,it will be converted into albite and leucite;mixed ash ash The slag is mainly quartz.When the temperature is low,the ash contains Na salt,K salt and mullite.When the temperature rises,the Na salt and K salt disappear,and the content of mullite and sillimanite increases.(3)Taking KW,WS and their mixtures as the research objects,the pore structure of ash samples under different ashing temperatures and different blending ratios were analyzed by BET isotherm adsorption/desorption experiment,FHH fractal model and SEM experiments.With the increase of ashing temperature,the BET specific surface area of KW,WS and their mixture ash samples increased first and then decreased.As the WS content increased,the BET specific surface area increased continuously.The FHH method is used to fit the adsorption curve,and the fractal dimension D1,D2 and D3 of three different stages are obtained(D1 reflects the fractal characteristics of micropores and small holes,and D2 is the fractal feature of partial mesopores.D3 is medium Fractal characteristics of holes and large holes,).For KW,WS and mixed ash samples at different ashing temperatures,the biggest change is D3,D1 and D2 are basically unchanged,the pore structure of mesopores is the most complicated,the pores and micropores are second,and the macropores are relatively simple..For the mixed ash samples with different blending ratios,the change of D3 is the largest,D1 and D2 are all changed,and the trend is basically increased.The large pores are relatively simple,and the micropores and mesopores are more complicated.