Abstract:

In order to resolve the utilization of solid-phase product generated in the process of coal-fired coupling biomass circulating fluidized bed gasification power generation, the effect of gasification temperature on fuel gas components, carbon content, specific surface area, micromorphology and adsorption capacity of the solid-phase products was investigated in Xiangyang power plant 6# unit with rice husk as the raw material. The results showed that, CO and H₂ contents in the gas increased first and then decreased with the increase of gasification temperature. When the temperature was 775 ℃, CO and H₂ contents arrived the highest values of 18.79% and 7.83%. During 625-775 ℃, a high calorific value of fuel gas, as well as the carbon content of solid-phase product, could be obtained. At a lower gasification temperature, a well-developed pore structure, an increased number of pores, and a medium thickness of pore wall could form and the larger specific surface area of solid-phase products increased by decreasing of the temperature. There was a linear correlation between the iodine adsorption value and the specific surface area. At 625 ℃, the maximum specific surface area of solid-phase products could be reached(145.3 m²/g), as well as the maximum adsorption capacity of iodine of 265 mg/g. The solid products are promising in the fields with a high consumption of adsorption materials while a relatively low demand for adsorption capacity.

Key words: coal coupled biomass power generation, circulating fluidized bed, biomass gasification, solid-phase product, adsorption