Experimental investigation of operation characteristics of a lab-scale dual fluidized bed by calcium looping process

Abstract

Even though calcium looping application for pre-combustion carbon dioxide capture itself has been demonstrated at TRL 6, modification on carbonator/gasifier structure is still desired for further enhanced sorption and tar reforming intensification. A lab-scale dual fluidized bed within a compact fluidized bed carbonator is the first time constructed and tested under electric-heating hot conditions, which is a critical step to develop to self-heat and pilot-scale system. The compact fluidized bed carbonator takes advantage under two coupled different fluidization regimes and reaction temperatures, and has more commonality and flexibility in future application. In this work, feasibility of long-term stable state operation on the lab-scale hot rig was proved and several tests were conducted to study its operation characteristics by calcium looping process. Normalized capture efficiency model for the compact fluidized bed carbonator is developed. Constructional constraints of reactor, different operating conditions and sorbent characteristics have strong effects on capture efficiency and active space time. This work provides a solid basis for future investigation of calcium-based sorption enhanced gasification or tar cracking intensification on this facility.