Steady state Fischer-Tropsch synthesis in supercritical propane

Journal Article · Sun Jan 01 04:00:00 EST 1995 · Industrial and Engineering Chemistry Research; (United States)

DOI:https://doi.org/10.1021/ie00040a004· OSTI ID:6575731

Lang, X; Akgerman, A; Bukur, D B ^[1]

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1. Texas A and M Univ., College Station, TX (United States)

Fischer-Tropsch synthesis (FTS) on a precipitated iron catalyst was conducted in a fixed bed reactor at baseline conditions of 1.48 MPa, 250 C, 2 L(NTP)/(h [times] g of cat), H[sub 2]/CO = 0.67, and in supercritical propane (total pressure of 7 MPa) while keeping the synthesis partial pressure and gas flow rate constant. The catalyst activity and lumped hydrocarbon product distribution under the supercritical conditions were similar to those obtained during reaction a the baseline conditions; however, higher selectivities of 1-olefins were obtained during the supercritical phase FTS. This suggests that the rate of FTS is not diffusion limited under the reaction conditions used in this study, whereas the secondary olefin hydrogenation and isomerization reactions are diffusion limited. An independent test in which nitrogen was used instead of propane showed that operation at a total pressure of 7 MPa does not have any effect on olefin selectivity. The observed increase in olefin selectivity during the supercritical FTS is due to higher diffusivities and desorption rates of high molecular weight olefins relative to normal FTS where the catalyst pores are filled with liquid hydrocarbons (wax).

• DOE Contract Number: FG22-92PC92545
• OSTI ID: 6575731
• Journal Information: Industrial and Engineering Chemistry Research; (United States), Journal Name: Industrial and Engineering Chemistry Research; (United States) Vol. 34:1; ISSN IECRED; ISSN 0888-5885
• Country of Publication: United States
• Language: English

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CARBON MONOXIDE
CARBON OXIDES
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CHEMICAL REACTION KINETICS
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