Fischer-Tropsch Synthesis. Some Important Variables of -the Synthesis on Iron Catalysts.

Fischer–Tropsch Synthesis: Deactivation as a Function of Potassium Promoter Loading for Precipitated Iron Catalyst

“…With further increases in the potassium content, the active sites may be blocked by potassium, resulting in a decline in catalyst activity. Furthermore, as stated earlier, the addition of potassium is in favor of carbon deposition on the surface, which leads to the formation of inactive carbon covering the active sites on the surface and thus leads to a further decline in the FTS activity [6,19]. The effect of potassium promoter loading on FTS activity/stability observed in the present study passes through a maximum at 0.5K/100Fe, and further increases in potassium loading increased the deactivation rate.…”

“…Nearly all iron-based FTS catalysts contain potassium as one of the promoters, although the amount can vary depending on the desired product distribution. The overall effects of potassium on the behavior of iron-based FTS catalysts have been investigated over different catalyst systems [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Kölbel [3] examined the effect of potassium on the surface properties of supported iron and precipitated Fe-Cu-SiO 2 catalysts, and found that the addition of potassium on the precipitated iron catalyst enhanced CO chemisorption and suppressed H 2 chemisorption.…”

“…The effects of potassium on the FTS and WGS activities and product selectivity have also been investigated over a variety of iron-based catalysts [13,17,19,20]. While some researchers have reported that FTS activity either increases [2,6,13] or passes through a maximum as a function of potassium loading [11,20], others have found that potassium either has no effect on the activity for FTS [21] or suppresses it [17,20]. In our previous study [22], we reported the activity/stability of an unpromoted and a 2 % potassium promoted iron catalyst during FTS, and the activities of these catalysts decreased in a similar manner with time on stream.…”

Cobalt–iron nano catalysts supported on TiO2–SiO2: Characterization and catalytic performance in Fischer–Tropsch synthesis

“…In this reaction, the effect of H2/CO ratio is remarkable, and in turn the lower H2/CO ratio in the reactor results in a higher C13+ selectivity. From the results, it can also draw the conclusions that the higher H2/CO ratio is preferential for chain termination to produce light hydrocarbons while lower H2/CO ratio is preferential for the chain growth and the production of heavy hydrocarbons [50][51]. Therefore, the C13+ selectivity decreased with increasing H2/CO ratio.…”

State of the art in biorefinery in Finland and the United States, 2008

“…Although pyrolysis oil has never been found useful for much other than direct combustion in boilers or possibly turbines, the gas produced in gasification can be reformed into a number of products including hydrocarbons much like diesel fuel, methane (the major component of natural gas), methanol, hydrogen, and higher-chain-length alcohols (Hamelinck 2004). Most notable from a historical perspective was the use of gasifiers by Germany to produce fuel-grade hydrocarbons from coal during World War II (Anderson, et al, 1952;Schulz, 1999) Coal gasification and Fischer-Tropsch reforming have also been used extensively by the Republic of South Africa (Stiegel and Maxwell, 2001;Schulz, 1999). Biomass, much the same as coal, can be converted to product gas and reformulated into the same variety of products.…”