Test Operation of a Separated-Gasification Chemical Looping Combustion System for Coal

摘要

Chemical looping combustion (CLC) has been one of the most attractive topics for the clean utilization of coal. Based on the staged-gasification of the solid fuel, a separated-gasification CLC apparatus for coal was established, which mainly consisted of a gasifier (GR), a reduction reactor (RR), and an air reactor (AR). This design separated the gasification of the coal avoiding the direct solid-solid contact between oxygen carriers and coal which was beneficial to lengthen the life cycle of the oxygen carriers. The established system was tested under both cold and hot conditions. The variable conditions of different amounts of fluidized gas and the air into AR were carried out to verify the feasibility and the stability of this system. Results indicated that the system could be operated stably under the variable conditions, showing acceptable pressure distributions in the reactor system. In the hot operation, the concentration of CO2 at the outlet of RR reached a relatively high level (92.7%-93.2%) while the CO2 concentration at the outlet of AR was 0.93%-1.12% during the stable durations. However, there was still a problematic condition, unstable operation of coal screw feeder, which needed further improvement.