Experiments are carried out in a bench-scale bubbling fluidized bed with silica sand at different bed temperature(750
800
850
and 900 ℃)to study the mechanism of bed material agglomeration during fluidization combustion of furfural residues. The results show that bed agglomeration and defluidization only take place at 900 ℃ during the experiment period(6 hours). XRD and SEM/EDS analyses on bed materials and agglomerate samples discharged from the bed after combustion show that the main reason that makes the fluidized bed have different characteristics of bed agglomeration and defluidization is the different composition of alkali metal potassium salt in furfural residue ash at different bed
temperature. The main composition of alkali metal potassium salt is KCl at 750 ℃
a mixture of KCl and K
2
SO
4
at 800 ℃
and a complex containing alkali metal potassium silicate compounds with Al and Ca above 800 ℃. The melting point of the complex is about 900 ℃. Thus
the melting of this complex compounds plays an important role in agglomeration and defluidization during combustion of furfural residue in fluidized bed. These results have certain reference value for choosing combustion temperature in furfural residue fluidization bed boiler.
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