Fischer-Tropsch Processes and Reactors

General aspects of the synthesis and of different processes are discussed in the literature, for example, by Anderson (1984), Dry (2002, 1981), Filers, Postuma, and Sie (1990), Falbe (1977), Haenel (2006), Schulz (1999), Zennaro, Hugues, and Caprani (2006), and Schaub, Rohde, and Subiranas (2006). For further details on different reactor types used for ET-synthesis we refer to Dry (2002), Jess, Popp, and Hedden (1999), Sie and Krishna (1999, 2000), Sie, Senden, and Van Wechem (1991), Zennaro, Hugues, and Caprani (2006), and Schaub, Rohde, and Subiranas (2006). Here we can only point out some main aspects of reactor technology and process design. 

Reactor capacities are in the range of 300 (fixed bed) to 1200 tonnes (slurry bubble column) of liquid hydrocarbons per day (Schaub, Rohde, and Subiranas, 2006). Low-temperature reactors have to cope with a three-phase reaction system (gas, liquid. 

7 7 Fuels and Chemicals from Syngas Methanol and Fischer-Tropsch Synthesis Hydrocracking 

Lujgt]. The conversion of syngas per pass is only about 30%, but by the installation of a gas recycle, usually with a recycle ratio of two to three, the overall conversion is in the range 70-80%. The limited conversion per pass helps to remove the reaction heat and by this means a temperature runaway can be avoided. Example 6.11.1 (adapted from Jess and Kem, 2009) examines some general aspects of the influence of the recycle ratio on reactor behavior. 

Example 6.11.1 Influence of recycle ratio on the behavior ofa FT reactor 

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