High temperature Fischer-Tropsch

Iron-based high-temperature Fischer-Tropsch (Fe-HTFT)... 

After the Second World War a gas-to-liquids facility that employed an iron-based high-temperature Fischer-Tropsch (Fe-HTFT) process was constructed at Brownsville, Texas. The technology was developed by Hydrocarbon Research, Inc.,20 and the commercial facility was operated by the Carthage Hydrocol Company. The Hydrocol plant was in commercial operation during the period 1951-1957, and it was shut down mainly for economic reasons (the oil price was around US 2 per barrel at that time). 

Change occurred in high-temperature Fischer-Tropsch reactor technology. The circulating fluidized bed Sasol Synthol reactors were replaced by fixed fluidized bed Sasol Advanced Synthol (SAS) reactors.44 This did not meaningfully affect the Fe-HTFT syncrude composition, but it reduced the operating cost of HTFT synthesis. 

Steynberg, A. P., Espinoza, R. L., Jager, B., and Vosloo, A. C. 1999. High temperature Fischer-Tropsch synthesis in commercial practice. Appl. Catal. A 186 41-54. 

The higher alkene feed (C10-14) for the production of detergent alcohols is either a product from the wax-cracker (terminal and internal alkenes) or the byproduct of the ethene oligomerisation process (internal alkenes). In the near future a feed from high-temperature Fischer-Tropsch may be added to this. The desired aldehyde (or alcohol) product is the linear one and the cobalt catalyst must therefore perform several functions ... 

Fischer-Tropsch Technology FTS can be carried out in several different reactor types fixed bed, fluidized bed, or slurry phase and at different temperatures. The high-temperature Fischer-Tropsch (HTFT) synthesis runs at 320°C-350°C, at which temperatures typically all products are in the gas phase [22], HTFT is operated in fluidized-bed reactors, with iron catalysts. Selectivities correspond to chain-growth probabilities in the range of 0.70-0.75 and are ideal for gasoline production, but olefins and oxygenates are formed as well and are used as chemicals. 

Table 11.3 Typical Product Distribution from High Temperature Fischer-Tropsch...

Fig. 2. Circulating [circulating fluidized bed (CFB)] and ebulating [fixed-fluidized bed (FFB)] reactors for high temperature Fischer-Tropsch operations (high gasoline and alkene production).

Fig. 5. Relation between the selectivities of the hydrocarbon cuts for the high temperature Fischer-Tropsch process. The selectivities are on a C atom % basis.

Fig. 8. The selectivity of methane as a function of the partial pressure factor (high temperature Fischer-Tropsch operation).

Although not as widely used as a gas-sofid PBR, FBR remains as the only choice for processes such as FCC and high-temperature Fischer-Tropsch (HTFT) synthesis, both of which have key roles in the petroleum processing and petrochemical industries. FCC is a critical step in petroleum refining and involves catalytic breakdown of heavy gas oil molecules into... 

Figure 1.16 High-temperature Fischer-Tropsch synthesis reactors, (a) Sasol Synthol circulating fluidized-bed reactor.

In principle, solids found in nature can display activity as heterogeneous catalysts (e.g., iron ores are applied in high temperature Fischer-Tropsch catalysis). However, after 100 years of intense research in catalysis it has been found that in most cases synthetic materials are more suitable as the reproducibility of their synthesis is higher and their specific properties can be adjusted by the synthetic procedure. 

Figure 6.11.9 XTL plant (X to liquid with X as natural gas, coal, biomass) with low or high temperature Fischer-Tropsch synthesis.

Table 18.4 The carbon number distribution of high-temperature Fischer—Tropsch (HTFT) and low-temperature Fischer—Tropsch (LTFT) products, excluding Ci—C2 hydrocarbons...

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