生物质合成灰的烧结熔融特性和矿物转变规律实验研究OACSTPCD

[Objective]The coking problem of biomass in fluidized bed combustion process was studied,and the influence of potassium salt form and content on the sintering and melting characteristics of biomass ash was analyzed.[Methods]The sintering and melting characteristics and the mineral transformation law of synthetic biomass ash were analyzed by experiments with scanning electron microscope coupled energy dispersive spectrometer,X-ray diffractometer,X-ray fluorescence,and FactSage thermodynamic calculation software.[Results]In the typical operating temperature range of 750-950℃,the sintering and melting degree of synthetic biomass ash aggravates with the increase of temperature and potassium salt mass fraction.In addition,the effects of different forms of potassium salt on the sintering and melting characteristics of biomass synthetic ash are also significantly different.When the potassium salt is in the form of K2CO3,the liquid phase in the synthetic ash could reach up to 34.36%,leading consequently to severe sintering of the ash.When the potassium salt is in the form of KCl,most of K and Cl elements escape at 750-850℃,and the sintering degree of synthetic ash is weakened in comparison with the K2CO3 situation.When the potassium salt is in the form of K2SO4,the liquid phase in the synthetic ash is the least,and the sintering and melting degree is also the weakest.[Conclusion]Changing the form of potassium salt and controlling the temperature of fluidized bed are expected to alleviate the coking problem of biomass in fluidized bed combustion.