Simulation and optimization of screw feeder in a bubbling fluidized bed gasification reactor

Abstract

A fluidized bed biomass gasification reactor is used to produce syngas from biomass and municipal wastes. Gasification is a flexible technology where many different types of feedstocks can be used. The University of South-Eastern Norway has a 20kW gasification reactor which is used to investigate the quality and quantity of the syngas produced using different types of feedstocks. At the present, the reactor has the challenge to supply feedstock to the reactor via transport screws. The main challenge consists of achieving continuous feeding and reduction in the feed rate. Therefore, this work is focused on the optimization of the screw feeder in the gasification reactor to obtain a reduced feed rate while maintaining a continuous feeding rate. The aim is to reduce the feed rate from approximately 8 kg/h to 3-4 kg/h without missing continuity of the feeding.

A model of the screw feeder is developed using CAD software SolidWorks and the model is simulated using open-source simulation software LIGGGHTS to investigate feed rate and continuity using different combinations of transport screw parameters. The simulation results are processed using Excel and viewed graphically with the open-source visualization software ParaView. The simulation results are compared to the experimental measurements in the gasification reactor. The validated model is further used to investigate the feed rate with different combinations of transport screw parameters and the results are compared and discussed.