Olefin readsorption mechanism model

The mesoscale effects on the product distribution of FTS should include two points as follow (1) the modified ASF product distribution and olefin readsorption mechanism model and (2) diffusion-reaction model and external-internal diffusion model of FTS process. 

Modified ASF Product Distribution and Olefin Readsorption Mechanism Model... 

In 1993, Lox and Froment (1993) proposed detailed dynamic model mechanism which based on FTS carbide mechanism, the model clarify the association between operating conditions change and FTS product distribution under classical ASF frame. This was the first attempt to develop detailed dynamic model. Recently, Ma and coworkers (Ma et ah, 1999a, 1999b) proposed a FTS detailed dynamic-olefin readsorption mechanism model, which indicates eigenactivity of olefin readsorption, the formation of which is shown in Eqs. (39)—(45), where R is the reaction rate of different hydrocarbons, R, is the reaction rate constant of different reactions, a is the chain-growth possibility corrected by is the... 

For this model, the product distribution of FTS should be determined or influenced by not only the chain-growth factor a but also the secondary reaction of olefins (/ ), which can direct the design of FTS catalyst and engineering enlargement. However, the olefin readsorption mechanism model needs to be studied further to clarify the intrinsic product distribution of FTS. 

Because the transient data for methanation reaction are more accurate than those for C2-C5 hydrocarbons. By decoupling the methanation reaction, rate coefficients for the initial part of the mechanism can be fixed, followed by correct account of readsorption of reactive olefins during subsequent modeling based on a plug-flow reactor model. 

---