费托合成钴基催化剂的研究进展

 费托合成油技术是煤炭、天然气等含碳资源清洁优化利用的重要途径, 其关键问题之一是催化剂选择性的调控, 即抑制甲烷生成和提高馏分油含量. 近 10 年来, 中国科学院山西煤炭化学研究所系统地开展了钴基费托合成催化剂及制备放大的工程基础研究, 包括钴分散度、还原度与甲烷生成之间的关系, 载体表面疏水性对催化剂性能的影响, 以及采用孔道限域等手段初步实现了产物的选择性调控. 同时, 初步阐明了甲烷生成的结构基础, 并指明了新型馏分油催化剂研发方向. 在此基础上, 研制了新型钴基催化剂, 其具有低甲烷选择性、高重质烃选择性和良好稳定性的特点. 目前, 对 I 型催化剂完成了实验室稳定性验证并实现了工业示范; 对 II 型催化剂 (甲烷选择性约 2%~3%) 完成了稳定性验证.

The Development of Cobalt-Based Catalysts for Fischer-Tropsch Synthesis

Fischer-Tropsch (F-T) synthesis is an important route to utilize fossil resources such as coal and natural gas. The key point is the control of catalyst selectivity, that is how to suppress methane formation and to improve distillate selectivity. In the past decade, Co-based F-T synthesis catalysts and related scale-up were investigated in our laboratory, including the relationship between cobalt dispersion, reducibility, and methane formation along with the hydrophobic modification and the core-shell structure. It was found that CH4 selectivity is correlated with the reducibility of cobalt, which depends on its particle size. Based on these, Co-based catalysts have been developed for the scale-up with the feature of low CH4 and high heavy hydrocarbon selectivity. Catalyst I is now subjected to the demo-plant of over 5 000 t/a, and Catalyst II (with much low CH4 selectivity) has operated for more than 8 000 h.