Bed agglomeration characteristics of rice straw combustion in a vortexing fluidized-bed combustor.
To investigate bed agglomeration characteristics, the combustion of pelletized rice straw was conducted in a bench-scale vortexing fluidized bed. Effects of bed temperature, superficial velocity, secondary gas velocities, and mass blended ratio of coal on the defluidization time were investigated. The alkali concentrations in different sections of the bed zone were also studied. The bed materials and agglomerates were analyzed using SEM/EDX to obtain the surface morphology and the compositions. The results revealed that the defluidization time is increased with superficial gas velocity and is decreased with bed temperature. Eutectic composition with low melting point materials promote defluidization at high temperatures. Effect of the secondary gas velocity on the defluidization time indicates different trends at different bed temperatures. The highest value of alkali concentration appears at upper bubbling zone. Coal ash can avoid the existence of a certain eutectic composition, and increases its melting point.
School of Energy and Environment, Anhui University of Technology, Maanshan 243002, Anhui Province, PR China.
Feng
F
Duan
Department of Chemical Engineering, Chung Yuan Christian University, Chungli 32023, Taiwan, ROC. Electronic address: cschyang@cycu.edu.tw.
Chien-Song
CS
Chyang
School of Energy and Environment, Anhui University of Technology, Maanshan 243002, Anhui Province, PR China.
Li-hui
LH
Zhang
Department of Chemical Engineering, Chung Yuan Christian University, Chungli 32023, Taiwan, ROC.
Siang-Fong
SF
Yin
D019149:Bioreactors; D001709:Biotechnology / Q000295:instrumentation* / Q000379:methods*; D003031:Coal; D012275:Oryza / Q000737:chemistry*; D011188:Potassium / Q000032:analysis; D012212:Rheology; D013052:Spectrometry, X-Ray Emission; D013997:Time Factors; D014866:Waste Products
D003031:Coal; D014866:Waste Products; D011188:Potassium
Agglomeration; Defluidization time; Pelletized rice straw; Vortexing fluidized bed