Abstract:

In this paper, the recent advances on the study of the Co-based catalysts for Fischer-Tropsch synthesis, i.e., the deactivation mechanism, regeneration method of catalyst and how to prolong the catalyst life,are reviewed. The main causes of catalyst deactivation in Co-based FTS are poisoning, sintering of Co, carbon deposition, re-oxidation, metal-support solid state reactions, surface reconstruction, surface blockage and attrition. Carbon deposition and sintering of Co are the main reasons of Co-based catalyst deactivation, the key to prolong the life of Co-based catalysts for FT synthesis is to improve the resistance to the sintering of Co and coke deposition. The resistance to the sintering of Co could be improved by enhancing the interaction between the active metal Co and the support, controlling the Co metal particle size distribution and adopting coated or confined method. The carbon deposition can be inhibited by adding promoters, adjusting the experimental conditions (e.g. H₂/CO, GHSV). The catalyst could be regenerated by hydrogen treatment, de-wax, oxidation and reduction, de-wax, oxidation, solution treatment and reduction, in order to reactivate catalyst efficiently, the selection of optimal regeneration method should be combined with the main reason of catalyst deactivation. In the future, it is the key to improve the stability of catalyst and solve the industrial scale-up research of catalyst regeneration technology.

Key words: syngas, catalyst, mechanism, regeneration, life time

摘要：

综述了钴基费托合成催化剂的失活机理、催化剂再生工艺及如何延长催化剂寿命的研究进展，通过分析催化剂失活原因，认为中毒、Co颗粒烧结、积炭、氧化、固相反应、晶相重构、表面阻塞和催化剂磨损等因素造成催化剂不同程度失活，其中积炭和Co颗粒烧结是催化剂失活的最主要原因，延长催化剂寿命的关键是提高催化剂的抗烧结能力和抑制积炭生成。增强活性金属Co和载体间的相互作用，保持Co晶粒分布均一或采用包覆、限域等策略可提高催化剂的抗烧结能力，通过添加助剂、调整氢碳比和空速等工艺参数亦可抑制积炭的生成。采用氢处理、脱蜡-氧化-还原和脱蜡-氧化-溶液处理-还原等工艺可实现催化剂的再生，对催化剂进行再生时要结合催化剂失活的主要原因，选择合适的再生工艺来最大限度地恢复催化剂活性。今后，提高催化剂的稳定性以及开发催化剂再生工艺技术路线是提高钴基费托合成技术竞争力的关键。

关键词: 合成气, 催化剂, 机理, 再生, 寿命