Retrospect and prospect of carbon stripper technology in solid-fuel chemical looping combustion

Abstract

The performance of carbon stripper (CS) directly affects the carbon capture of in-situ gasification chemical looping combustion systems. This paper describes the separation mechanism of existing CS methods and reviews current CS technologies. The internal CS shows moderate carbon capture efficiency of 82–96%. However, it interferes with the gas-solid flow and reaction in fuel reactor. The external CSs are mainly based on bubbling fluidized beds with the carbon capture efficiency between 60 and 99%. Due to the lower gas velocity for fluidization, the residence time of particles is sufficient, while the collision and friction forces between particles increase. The inertial separator CS shows favorable separation performance under high-flux conditions with the carbon capture efficiency of around 97%, while its adaptability needs to be improved. The operating gas velocity, solid flux, and physical properties of particles in CS significantly affect its separation performance. The specialized structure optimizations are found to be able to improve the CS separation performance directly. Besides, the balance between separation efficiency and complex structure in CS should be fully considered. With different research methods including typical experimental testing, computational fluid dynamics and particle image velocimetry, the current problems of CS are expected to be ameliorated in the future.