Low severity upgrading of F-T waxes with solid superacids

Technical Report · Wed Jan 01 00:00:00 EST 1992

DOI:https://doi.org/10.2172/6855179· OSTI ID:6855179

Tierney, J W; Wender, I

In the past year, we synthesized a Pt/ZrO[sub 2]/SO[sub 4] catalyst which exhibits high conversions and selectivity for desirable products from long-chain paraffins, such as n-hexadecane, n-dotriacontane(n-C[sub 32]) and a SASOL wax(C[sub 58]-C[sub 64]). The catalyst preparation procedure has been carefully worked out and is reproducible. Isomerization and hydrocracking activities of long-chain paraffins and selectivities to various products were examined under mild conditions: 443 K and 2.5 MPa initial hydrogen pressure. Effects of temperature, pressure, catalyst loading, Pt concentration on n-alkane conversions were studied to understand the mechanism on the acid catalyst surface. Upgrading of the alkanes proceeds through initial isomerization followed by [beta]-scission reactions and further isomerizations. Isomerization is favored at low temperature and short reaction times, whereas cracking is favored at higher temperatures or pressures. The hydrogen pressure has a considerable influence on the product distribution. Hydrogen transfer probably proceeds through dissociation of molecular hydrogen to generate pretonic acid sites which cause C-C cleavage. Effect of increasing Pt loadings shows a trend similar to increasing hydrogen pressure. Characterization of the present catalyst demonstrates that catalytic activity depends to a large extent on proper coordination of finely dispersed platinum to strong acid sites as well as on pore size distribution.

• Research Organization: Pittsburgh Univ., PA (United States). Dept. of Chemical and Petroleum Engineering
• Sponsoring Organization: USDOE; USDOE, Washington, DC (United States)
• DOE Contract Number: FG22-91PC91304
• OSTI ID: 6855179
• Report Number(s): DOE/PC/91304-T4; ON: DE93008123
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ALKANES
HYDROCRACKING
ISOMERIZATION
PARAFFIN
WAXES
CATALYSTS
CHEMICAL REACTION KINETICS
PLATINUM
PROGRESS REPORT
SULFATION
ZIRCONIUM OXIDES
CHALCOGENIDES
CHEMICAL REACTIONS
CRACKING
DECOMPOSITION
DOCUMENT TYPES
ELEMENTS
HYDROCARBONS
KINETICS
METALS
ORGANIC COMPOUNDS
OTHER ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
PLATINUM METALS
PYROLYSIS
REACTION KINETICS
THERMOCHEMICAL PROCESSES
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
ZIRCONIUM COMPOUNDS
400201* - Chemical & Physicochemical Properties