KINETIC AND STRUCTURAL STUDIES OF REGENERATION OF SULFIDED DOLOMITE IN CARBON DIOXIDE II THE CYCLIC REGENERATION

Regeneration of sulfided dolomite in CO2, an alternative to regeneration in CO2/H2O, has been conducted in a TGA system up to 20 cycles under the optimal regeneration condition, The solid sorbent has shown a much slower deterioration in sulfidation capacity upon cycling by regeneration in CO2 than in CO2/H2O. The utilization of Ca reached 50% in the 20th cycle. compared with the 20% by the CO2/H2O regeneration, The XES sulfur profile of partially reacted samples indicated a switch in reaction pattern, both in sulfidation and regeneration, from topochemical to nontopochemical at the 3th/4th cycle. Incorporating the concept of solid deactivation, a. cyclic regeneration model was developed and successfully predicts the progress of regeneration in a specific cycle and the trend of change in reaction pattern.