Effect of process conditions on olefin selectivity during conventional and supercritical Fischer-Tropsch synthesis

Journal Article · Tue Jul 01 04:00:00 EDT 1997 · Industrial and Engineering Chemistry Research

DOI:https://doi.org/10.1021/ie960507b· OSTI ID:529744

Bukur, D B; Lang, X; Akgerman, A; Feng, Z ^[1]

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

A precipitated iron catalyst (100 Fe/5 Cu/4.2 K/25 SiO{sub 2} on mass basis) was tested in a fixed-bed reactor under a variety of process conditions during conventional Fischer-Tropsch synthesis (FTS) and supercritical Fischer-Tropsch synthesis (SFTS). In both modes of operation it was found that: total olefin content decreases whereas 2-olefin content increases with either increase in conversion or H{sub 2}/CO molar feed ratio. Total olefin and 2-olefin selectivities were essentially independent of reaction temperature. The effect of conversion was more pronounced during conventional FTS. Comparison of olefin selectivities in the two modes of operation reveals that total olefin content is greater while the 2-olefin content is smaller during SFTS. Also, both the decrease in total olefin content and the increase in 2-olefin content with increase in carbon number (i.e., molecular weight of hydrocarbon products) was significantly less pronounced during SFTS in comparison to the conventional FTS. The obtained results suggest that 1-olefins, and to a smaller extent n-paraffins, are the primary products of FTS. Secondary reactions (isomerization, hydrogenation, and readsorption) of high molecular weight {alpha}-olefins occur to a smaller extent during SFTS, due to higher diffusivities and desorption rates of {alpha}-olefins in the supercritical propane than in the liquid-filled catalyst pores (conventional FTS).

• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: FG22-92PC92545
• OSTI ID: 529744
• Journal Information: Industrial and Engineering Chemistry Research, Journal Name: Industrial and Engineering Chemistry Research Journal Issue: 7 Vol. 36; ISSN IECRED; ISSN 0888-5885
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
ALKENES
CATALYSTS
CATALYTIC EFFECTS
CHEMICAL REACTION KINETICS
COPPER
FISCHER-TROPSCH SYNTHESIS
IRON
PARAMETRIC ANALYSIS
PERFORMANCE TESTING