Fischer-Tropsch synthesis added olefin reactions

Schulz, H., and Claeys, M. 1999. Reactions of a-olefins of different chain length added during Fischer-Tropsch synthesis on a cobalt catalyst in a slurry reactor. Appl. Catal. A 186 71-90. 

The Fischer-Tropsch synthesis follows a polymerization mechanism where a Q unit is added to the growing chain. A simplified representation of the reaction network is shown in Fig. 1, where the key points are termination by either H-abstraction to give a-olefins or by hydrogenation to give w-paraffins. 

Fischer-Tropsch synthesis, 28 80, 97, 103, 30 166-168, 34 18, 37 147, 39 221-296 activation energy and kinetics, 39 276 added olefin reactions, 39 251-253 bed residence time effects on chain growth probability and product functionality, 39 246-250... 

D. Reactions of Added Olefins During Fischer-Tropsch Synthesis... 

Dimerization and codimerization reactions are widely used on an industrial scale either to provide chemicals of high added value or to upgrade by-product olefinic streams coming from various hydrocarbon cracking processes (steam or catalytic cracking) or hydrocarbon forming processes (Fischer-Tropsch synthesis or methanol condensation) (e. g., according to eq. (1)). 

To investigate the role of readsorption and secondary conversion during Fischer-Tropsch synthesis, experiments were performed in which small amounts of ethylene were added to the synthesis gas before reaction. The fate of the olefin was then followed as a function of reaction time. In the case of ethylene (2.7 mol % in synthesis gas) under the present reaction conditions, 80-90% of the added olefin reacted. As shown in Figure 13, the predominant reaction was hydrogenation to ethane, but approximately 10% of the added ethylene was incorporated into growing chains. The incorporation of ethylene into chain products increased the relative amounts of C3 to C5 hydrocarbons as shown in Figure 14. To further demonstrate this effect, a series of experiments were performed in which the initial concentration of ethylene was varied while all other... 

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