Abstract
Fischer-Tropsch synthesis (FTS) was studied on a precipitated iron catalyst in a fixed-bed reactor under both "supercritical" (propane or n-hexane as supercritical fluids; P = 4.1-7.0 MPa) and conventional operating conditions (P = 1.48 MPa), as well as in a stirred tank slurry reactor (STSR) under conventional conditions. Catalyst activity in the supercritical mode of operation was slightly higher than during conventional FTS in the fixed-bed reactor (FBR). This is attributed to higher diffusivities of reactants in supercritical fluids relative to the conventional mode of operation (pores filled with liquid hydrocarbon wax). Catalyst activity was significantly lower in the STSR than in the FBR, due to incomplete reduction of the catalyst in the STSR. Hydrocarbon selectivities in the FBR were similar in both modes of operation. Methane selectivity in the STSR was lower and C 5 + selectivity higher than in the FBR, due to better temperature control in the former and differences in the extent of mixing and 1-olefin readsorption. Total olefin selectivity of high molecular weight olefins was lower and 2-olefin selectivity was higher in the STSR than in the FBR at similar conversions. This indicates that olefin selectivity is not controlled by intraparticle diffusion. It appears that the olefin selectivity in the STSR is largely determined by the residence time of high molecular weight 1-olefins in the liquid phase, 1-olefin solubility dependence on carbon number, and adsorption/desorption phenomena at the catalyst surface.
| Original language | English |
|---|---|
| Pages (from-to) | 6038-6044 |
| Number of pages | 7 |
| Journal | Industrial and Engineering Chemistry Research |
| Volume | 44 |
| Issue number | 16 |
| DOIs | |
| Publication status | Published - 3 Aug 2005 |
| Externally published | Yes |
Fingerprint
ASJC Scopus subject areas
- Polymers and Plastics
- Environmental Science(all)
- Chemical Engineering (miscellaneous)
Cite this
Comparative study of an iron fischer-Tropsch catalyst performance in stirred tank slurry and fixed-bed reactors. / Bukur, Dragomir B.; Lang, Xiaosu; Nowicki, Lech.
In: Industrial and Engineering Chemistry Research, Vol. 44, No. 16, 03.08.2005, p. 6038-6044.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Comparative study of an iron fischer-Tropsch catalyst performance in stirred tank slurry and fixed-bed reactors
AU - Bukur, Dragomir B.
AU - Lang, Xiaosu
AU - Nowicki, Lech
PY - 2005/8/3
Y1 - 2005/8/3
N2 - Fischer-Tropsch synthesis (FTS) was studied on a precipitated iron catalyst in a fixed-bed reactor under both "supercritical" (propane or n-hexane as supercritical fluids; P = 4.1-7.0 MPa) and conventional operating conditions (P = 1.48 MPa), as well as in a stirred tank slurry reactor (STSR) under conventional conditions. Catalyst activity in the supercritical mode of operation was slightly higher than during conventional FTS in the fixed-bed reactor (FBR). This is attributed to higher diffusivities of reactants in supercritical fluids relative to the conventional mode of operation (pores filled with liquid hydrocarbon wax). Catalyst activity was significantly lower in the STSR than in the FBR, due to incomplete reduction of the catalyst in the STSR. Hydrocarbon selectivities in the FBR were similar in both modes of operation. Methane selectivity in the STSR was lower and C 5 + selectivity higher than in the FBR, due to better temperature control in the former and differences in the extent of mixing and 1-olefin readsorption. Total olefin selectivity of high molecular weight olefins was lower and 2-olefin selectivity was higher in the STSR than in the FBR at similar conversions. This indicates that olefin selectivity is not controlled by intraparticle diffusion. It appears that the olefin selectivity in the STSR is largely determined by the residence time of high molecular weight 1-olefins in the liquid phase, 1-olefin solubility dependence on carbon number, and adsorption/desorption phenomena at the catalyst surface.
AB - Fischer-Tropsch synthesis (FTS) was studied on a precipitated iron catalyst in a fixed-bed reactor under both "supercritical" (propane or n-hexane as supercritical fluids; P = 4.1-7.0 MPa) and conventional operating conditions (P = 1.48 MPa), as well as in a stirred tank slurry reactor (STSR) under conventional conditions. Catalyst activity in the supercritical mode of operation was slightly higher than during conventional FTS in the fixed-bed reactor (FBR). This is attributed to higher diffusivities of reactants in supercritical fluids relative to the conventional mode of operation (pores filled with liquid hydrocarbon wax). Catalyst activity was significantly lower in the STSR than in the FBR, due to incomplete reduction of the catalyst in the STSR. Hydrocarbon selectivities in the FBR were similar in both modes of operation. Methane selectivity in the STSR was lower and C 5 + selectivity higher than in the FBR, due to better temperature control in the former and differences in the extent of mixing and 1-olefin readsorption. Total olefin selectivity of high molecular weight olefins was lower and 2-olefin selectivity was higher in the STSR than in the FBR at similar conversions. This indicates that olefin selectivity is not controlled by intraparticle diffusion. It appears that the olefin selectivity in the STSR is largely determined by the residence time of high molecular weight 1-olefins in the liquid phase, 1-olefin solubility dependence on carbon number, and adsorption/desorption phenomena at the catalyst surface.
UR - http://www.scopus.com/inward/record.url?scp=23844448736&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=23844448736&partnerID=8YFLogxK
U2 - 10.1021/ie0492146
DO - 10.1021/ie0492146
M3 - Article
VL - 44
SP - 6038
EP - 6044
JO - Industrial and Engineering Chemistry Research
JF - Industrial and Engineering Chemistry Research
SN - 0888-5885
IS - 16
ER -