关键词: 海藻生物质, 流化床, 床温, 风速, 床高

Abstract: Fluidized bed combustion experiment of two seaweed particles(Enteromorpha clathrata and Sargassum natans)was carried out in a bench-scale combustor.When seaweed particles were fed into the fluidized bed, dehydration and release of volatile matter happened.Devolatilization and burning of volatile matter of seaweed particles during fluidized bed combustion happened in about 1 min, followed by combustion of char.Combustion of char accorded with the shrinking core model in which carbon nucleus burned layer by layer from outside to inside and ash layer radius remained almost constant.As volatile matter was released at the beginning of combustion, Sargassum natans particles fractured immediately after they were fed into the fluidized bed.SEM analysis was used to study the cross-sections of Enteromorpha clathrata particles and their chars collected at different combustion periods.During the combustion process of Enteromorpha clathrata particles, internal porosity of particles increased gradually.The micro-pore surface became rougher.By feeding a few seaweed particles at a time,combustion of two seaweed particles(Enteromorpha clathrata,Sargassum natans)was also studied in the fluidized bed.During combustion of Enteromorpha clathrata particles, relative concentration of NO_x increased, while relative concentration of CO decreased.The SO₂ and NO_x released from Sargassum natans particles were more than those from Enteromorpha clathrata particles.CO concentration also decreased with increasing bed temperature.Increasing bed temperature intensified heat transfer in the combustor. Devolatilization of two kinds of seaweed happened earlier, and burnout time both shortened.Increase of air velocity and bed height facilitated combustion of two kinds of seaweed and shortened their burnout time.

Key words: seaweed biomass, fluildized bed, bed temperature, air velocity, bed height