| Abstract
| - The performance of a ZnO-doped manganese oxide MZ(1:0.1) as a regenerable sorbent for hotcoal gas desulfurization in 70-cycles tests in a fixed bed reactor has been studied. Sulfidationhas been carried out at 700 °C using a simulated RKW coal gas, while regeneration of the sulfidedsorbent has been conducted at 800 °C using pure air. The performance was very good as deducedfrom low pre-breakthrough H2S concentration in the outlet gas, high sorbent efficiency, and longdurability. Despite that, a slight efficiency decay was observed that will make the sorbent becomeinactive after a certain number of successive cycles in use. Simple methods of preparation, similarto those used in the manufacture of the original fresh sorbents, are shown to be effective inrecovering the activity of this sorbent. Additionally, because manganese sulfate plays an importantrole in the long durability exhibited by manganese based sorbents, the evolution of this compoundin the reactor bed in a typical regeneration test has been studied by FTIR spectroscopy. It isformed during the first stages of regeneration but it decomposes then, although not completely,in the last stages of the process, acting as a por-forming additive, like graphite, in every cycle.
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