(480f) Experimental Study of a Riser-Based Carbon Stripper in a Solid Fuel-Chemical Looping Combustion System
AIChE Annual Meeting
2017
2017 Annual Meeting
Particle Technology Forum
Fluidization and Fluid-Particle Systems for Energy and Environmental Applications II
Wednesday, November 1, 2017 - 9:26am to 9:43am
A three-fluidized-bed system was constructed based on Glickmanâs simplified scaling ratios. The system is comprised of a fuel reactor, an air reactor and a carbon stripper in between. The fuel reactor is a bubbling fluidized bed; the air reactor is a riser which transports solid particles back into the fuel reactor, and the carbon stripper is riser-based. Plastic beads and ilmenite particles were used to simulate the fluidization behavior of char particles and oxygen carrier particles. Pressure profile, solid circulation rate, separation ratio and separation efficiency were measured and calculated to study the separation characteristics of the carbon stripper.
Long-term stable operations were achieved and results have proven the feasibility of the proposed three-reactor system. Solid circulation rate can be easily controlled by adjusting the fluidization gas velocity of loopseals. With an increase of gas velocity in the carbon stripper, more particles were elutriated back to the fuel reactor and the separation ratio and separation efficiency increased. With mixture feeding rates below 17 kg/m2s, the separation efficiency increased from 71% to 97% as the gas velocity increased from 0.8 m/s to 1.6 m/s. Energy-cost ratios were calculated, and gas velocity higher than 0.8 m/s and mixture feeding rates lower than 17 kg/m2s were preferred.
The separation characteristics of a carbon stripper is of vital importance to the operation of a three-fluidized-bed CLC system. The results of this paper reveals that carbon strippers can be used to increase the carbon capture efficiency and that riser is an economically feasible way to realize carbon stripping in a CLC system.