Performance of a volatiles distributor equipped with internal baffles under different fluidization regimes

Artikel i vetenskaplig tidskrift, 2022

Chemical looping combustion of biomass is a promising carbon capture technology due to its inherent CO2 separation advantage. However, complete fuel conversion, particularly volatiles conversion for biomass, is usually not achieved in the fuel reactor. A novel concept named volatiles distributor (VD) has been proposed and tested in a cold-flow fluidized-bed, which shows good potential to achieve a more uniform horizontal distribution of the volatiles and improve the gas-solid contact. In this work, the VD has been further developed by introducing an array of internal baffles inside the VD. The objective is to improve the horizontal gas distribution and reduce the volatiles slip from the bottom of the VD. The results show that the uniformity of the horizontal distribution is improved significantly by the VD equipped with the internal baffles, especially in the single and multiple bubble regimes. The volatiles slip from the bottom of the VD is reduced by the installation of internal baffles according to the visual observation, even though there is a higher CO2 concentration detected above the bottom edge of the VD near the wall. A pronounced back-mixing of gas near the wall in the main riser may be the principal reason for the higher measured CO2 concentration.