Effect Of Pulverized Coal Ash On Migration And Transformation Of K,Cl During Biomass Combustion And Its Mechanism

The sustainable development of society is constrained by problems such as shortage of fossil energy,global environmental pollution.In this regard,humans have proposed a strategy to accelerate the transformation of energy structure.Thus,vigorously developing green renewable energy has become an inevitable trend.As a green and clean renewable energy,biomass energy will be of great significance for accelerating the transformation of energy structure.However,the content of K,Cl in biomass is high,which causes the problem of ash,slagging and corrosion of boiler heating area in the combustion process,which seriously jeopardizes the safe and economic operation of boiler equipment,which greatly restricts the application and development of biomass direct combustion technology.Pulverize coal ash is rich in reserves and low in price,and it is an excellent composite additive.In this paper,pulverized coal ash was used as additive to study the effect of pulverized coal ash on the migration and transformation of K,Cl during biomass combustion,thus revealing the mechanism of ash deposition,slagging and corrosion during biomass combustion.The research contents are as follows:For wheat straw and corn stalk,the effects of combustion temperature and biomass on the migration and transformation of K,Cl in biomass ash were studied.The results showed that the content of K,Cl in the two biomass ash decreased with the increase of combustion temperature,but the degree of slagging was different due to the different migration and transformation laws of K,Cl in the two biomass.Two different kinds of pulverized coal ash were selected as additives.The effects of addition ratio and type,combustion temperature,biomass type on the migration and transformation of K,Cl in biomass ash were investigated.The results showed that with the pulverized coal ash AF1 and AF2 as additives,the optimal addition ratio was 20%for wheat straw ash and 11%for cofn straw ash.Two types of pulverized coal ash are added,and a high-melting-point potassium compound and a chlorine-containing compound are formed in the bottom ash,so that the content of K,Cl in the bottom ash is reduced,and the ash,slagging and corrosion in the combustion process of the biomass are improved.In order to strengthen the effect of pulverized coal ash additive,CaO and Al2O3 were added to the proportion,and the factors such as the ratio and type of addition,the combustion temperature and the type of biomass were investigated.The impact of Cl migration conversion.The results showed that the optimal addition ratio of modified pulverized coal ash AF1 and modified pulverized coal ash AF2 to wheat and corn stover ash,was n[CaO:Al2O3:SiO2]?1:2:2.Adding modified pulverized coal ash AF1 and AF2,both K,Cl in the biomass are fixed in the bottom ash,and high-melting potassium compounds and chlorine-containing compounds are formed to alleviate the sintering and corrosion of the biomass ash.