Measurement and characterization of biomass mean residence time in an air-blown bubbling fluidized bed gasification reactor

FUEL

卷:253

Article

Agu, Cornelius E.¹  Pfeifer, Christoph²  Eikeland, Marianne¹  Tokheim, Lars-Andre¹  Moldestad, Britt M. E.¹ 

[1] Univ South Eastern Norway, Dept Proc Energy & Environm Technol, N-3918 Porsgrunn, Norway

[2] Univ Nat Resources & Life Sci, Dept Mat Sci & Proc Engn, A-1190 Vienna, Austria

关键词: Biomass gasification;    Residence time;    Char accumulation;    Bubbling bed;    Devolatilization;   

DOI  :  10.1016/j.fuel.2019.05.103

来源: Elsevier

【 摘 要 】

Gasification of biomass in bubbling fluidized beds can be limited by accumulation of unconverted char particles during the process. The amount of unconverted biomass depends on the residence time of the fuel particles. This study demonstrates a method for measuring the biomass residence time over the conversion period at a given air flowrate and a given amount of biomass in a bubbling bed using the variation of bed temperature and fluid pressure recorded over time. The results show that biomass conversion is characterized by the devolatilization and extinction times. The two biomass residence times increase with decreasing air flowrate and increasing amount of biomass charged in the bed. The amount of unconverted char between the two characteristic times also increases with decreasing air flowrate and increasing biomass load. The total heat loss during the devolatilization is observed to increase with increasing air flowrate and amount of biomass in the bed. Correlations are proposed for predicting the mean biomass residence time, the amount of unconverted char particles and the devolatilization heat loss at a given operating condition. The results of this study can be used in determining the bubbling bed properties and solid circulation rate required to decongest the accumulated char particles in the bed.

【 授权许可】

Free