An improved core-in-shell sorbent for desulfurizing hot coal gas

An improved core-in-shell sorbent for desulfurizing hot coal gas was investigated. An unusual calcium-based sorbent was prepared by pelletizing powdered limestone and then applying a coating of cement and limestone to the pellets. The coatings were strengthened by extended tumbling in a drum pelletizer, followed by steam curing to hydrate the calcium silicates and aluminates. The results showed that the pellets with the thinner shell composed of 60 wt% limestone offered the best compromise between crushing strength and absorption capacity. It was concluded that repeated loading and regeneration of the sorbent resulted in a gradual loss of reactivity, which was probably due to sintering.