Numerical Study on the Hydrodynamics Behaviour in Bubbling Fluidized Bed for Sewage Sludge Gasification

Sewage sludge is high moisture bio-solid produced during the sewage treatment. Gasifying sewage sludge based on the fluidization technology becomes a promising method of waste management to achieve energy recovery for sustainability and environmental protection. The hydrodynamics behaviour of sewage sludge in the fluidized bed is crucial to obtain an effective gasification process. In this numerical study, sewage sludge and saw dust are adopted as the feedstock for gasification, and air is continuously injected from the bottom of the fluidized bed. The multiphase flows of sewage sludge, saw dust and air are studied and compared under different operating conditions based on the Euler-Euler model. The results are capable of serving as reference for the design and optimisation of the sewage sludge gasification to improve the effectiveness.