The Study On Ash Fusion And Viscosity-temperature Characteristics Of Blend Ash Of Straw Biomass And Coal

Co-gasification of biomass and coal can not only make up the disadvantages of biomass gasification, but also produce positive meaning to promoting the grade of biomass utilization, and enriching as well as improving the entrained-flow gasification technology. Based on the entrained flow co-gasification technology of biomass and coal, the physicochemical properties of different biomass (rice straw, corn stalk and cotton straw) ashes of different ashing temperature were explored, and the ash fusion characteristics of Liuqiaoyikuang coal, Qinglongkuang coal, Baodian coal, Yulin coal with rice straw, corn stalk, cotton straw were also studied. Meanwhile, the characteristics of viscosity-temperature of blending ash at the blend ratio of 10% were also studied by high-temperature viscometer. Different models of ash fusion temperature were used to predict the blend ash fusion temperature of biomass and coal.The result shows that crop straw ashes have quite high content of alkali metals (especially potassium) and quite low fusion point (especially corn straw ash), which can easily cause the corrosion, slagging, and fouling of equipment. Although some amount of K in the form of KCl and (KC1)2 are released into the gas phase at higher ashing temperature, the fusion temperatures of three kinds of crop straw ash are not affected obviously by the different ashing temperature. It is more exact and referenced that the straw biomasses were ashed at a lower temperature (such as<700℃). The addition of 3 kinds of crop straw reduces the ash flow temperature of Liuqiaoyikuang coal and Qinglongkuang coal significantly, and the flow temperature of coal ash can be reduced to 1380℃at the blend ratio of 30%. Though the addition of rice straw increases the ash flow temperature of Yulin coal, the flow temperatures of mixtures are less than 1300℃at all blend ratios. The viscosity-temperature characteristic of Baodian coal ash was improved by the addition of crop straw, and the lowest operating temperature of gasifier can be reduced by 20℃. Due to the emergence of anorthite, the viscosity increased with decreasing the temperature of melting ash. According to the ash fusion temperature of biomass and coal blending in different proportions, the predicting flow temperature of neural network model was more exact and referenced.