The affect of alkali metal in biomass ash on operation of fluidized gasification

As a result of certain content of alkali metal in biomass, in the process of thermal transition, the alkali metal enriches to the bed materials, and forms low-melting compound which lead agglomeration. In the paper, sand, bauxite and periclase are used as three different kinds of bed materials, while, at last alkali metal in biomass enriched to bed materials for all the three kinds of materials. Alkali metal and SiO₂ forms low-melting compound, which would destroy the fluidization in furnace. And then the temperature of some part will become high, which promote the formation of low-melting compound. Finally, the slag is formed in the furnace, and then the system operation stops.