气氛环境对S Zorb吸附剂中硅酸锌生成的影响

针对S Zorb吸附脱硫工业运行装置中因硅酸锌的生成导致吸附剂活性严重降低等问题,在模拟工况、不同气氛条件下,对不同状况的S Zorb吸附剂进行处理,探讨硅酸锌的生成与环境及硅源的关系。结果表明:在550℃、干燥或纯水蒸气条件下,新鲜剂中难以生成硅酸锌;在550℃、有再生剂或待生剂存在的水热条件下,新鲜剂中有明显的硅酸锌生成;待生剂或再生剂中ZnS在焙烧过程中产生的SO2与高温水热环境之间的协同作用加速了硅酸锌的生成;在水热伴随酸性物质的环境下,待生剂上持硫量越高,硅酸锌的生成量越大;当待生剂上已有硅酸锌存在时,其再生过程中硅酸锌的生成速率进一步加快;不同硅源生成硅酸锌的差异较大,具有规整结构的硅源抗水热酸环境的能力较强。

EFFECT OF ATMOSPHERE ON ZINC SILICATE FORMATION IN S ZORB SORBENTS

The commercial operation indicated that the formation of Zinc Silicate is one of the key reasons for the deactivation of S Zorb sorbent. The commercial used sorbents in different state are tested under simulated industrial conditions with different atmospheres to investigate the relations of Zn2SiO4 formation with atmospheric environment and the silicon source. The results show that it is difficult to form Zn2SiO4 in fresh sorbent in simply dry or water vapor atmosphere even at 550℃. While Zn2SiO4 appears when the spent sorbent or regenerated sorbent coexists with the fresh one under hydrothermal condition at this temperature. The collaboration generated between SO2 produced during calcination of ZnS and high temperature hydrothermal surrounding will promote the formation of Zn2SiO4. The results also show that in the atmosphere of hydrothermal and acid, the more S in the spent sorbent, the more Zn2SiO4 formed. The growth rate of Zn2SiO4 will increases if Zn2SiO4 already exists in the spent sorbent. Different Si source will cause a different trend in the formation of Zn2SiO4, where the structured Si sources possess stronger resistance to hydrothermal-acid environment. Key words：S Zorb sorbent；Zinc Silicate；acid atmosphere