Continuous sorbent reactions in a high-temperature fabric filter followingconvective pass Ca(OH)(2) injection for SO2 removal

A specially designed two-stage reactor was used to study solid sorbent reac tions in the filtration stage of a high-temperature fabric which follow con vective pass Ca(OH)(2) injection. Solid conversions during the progress of the sorbent reactions were thoroughly analyzed. It was found that, unlike t he sorbent reactions in the injection stage, which proceed extremely fast w ith strong carbonation under high temperatures, the subsequent sorbent reac tions in the filtration stage are much slower and residual sorbent is mainl y utilized in removing sulfur dioxide (SO2). Two major reaction pathways ar e discovered in the filtration stage. The first route is through the decomp osition of residual calcium hydroxide (Ca(OH)(2)), which is critical in ind ucing further sorbent reactions when there is sufficient residual sorbent. The second route is the sulfation of the carbonation product, calcium carbo nate (CaCO3), which may become the principal reaction to remove SO2 after t he residual sorbent is consumed. The convective pass and the fabric filter are found to be equally important reaction sites in the combined process of convective pass sorbent injection with high-temperature filtration. The ov erall SO2 removal efficiency of the system is affected by both the sorbent injection and filtration conditions.