Deactivation and regeneration of alkali metal promoted iron Fischer-Tropsch synthesis catalysts

Abstract

Abstract Potassium promoted iron Fischer-Tropsch synthesis (FTS) catalyst showed a low deactivation rate of 0.083% per day after an initial conditioning period of 300 hours. Beryllium promoted iron catalyst produced an even more stable activity than potassium promotion, with a deactivation rate as low as 0.0062% per day. Higher temperature generated a shorter conditioning period for potassium promoted catalyst. For potassium promoted catalyst, FTS activity, CO 2 selectivity, hydrocarbon productivity and water gas shift activity showed the same conditioning period of 300 hours of time on stream after passing a peak value at about 120 hours of reaction time. A higher water gas shift activity, higher CO 2 and CH 4 selectivity was obtained for the beryllium promoted catalyst than by potassium. Beryllium promoted catalyst also showed a superior regenerability when either H 2 or CO was utilized. When rejuvenated with CO a better activity recovery was achieved than with H 2 .