TITLE: Low severity upgrading of F-T waxes with solid superacids.  Quarterly report, September 1, 1993--November 30, 1993.

AUTHOR: J. W. Tierney;   I. Wender.

INST.  AUTHOR: Pittsburgh Univ., PA. Dept. of Chemical and Petroleum Engineering.

SPONSOR: Department of Energy, Washington, DC.

LANGUAGE: English

PUB.  TYPE: Technical Report

PUB.  COUNTRY: United States

SOURCE: Department of Energy [DE],  31 Jan 94,  12p.

NTIS ORDER NO.: DE94010298INW

ABSTRACT:

During the last quarter we characterized the acidity of platinum-promoted solid superacids by TPD (temperature-programmed desorption) and investigated the effect of sulfate concentration on the activity of Pt/ZrO(sub 2)/SO(sub 4) catalysts for isomerization and hydrocracking of n-hexadecane. The activities of Pt/ZrO(sub 2) promoted by different anions (SO(sub 4)(sup 2 (minus)), MoO(sub 4)(sup 2(minus)) and WO(sub 4)(sup 2(minus))), to give Pt/ZrO(sub 2)/SO(sub 4), Pt/ZrO(sub 2)/MoO(sub 4) and Pt/ZrO(sub 2)/WO(sub 4), were compared and the results related to their acidity and acid strength determined by TPD. TPD was an effective tool for the rapid evaluation of the acidity of metal-promoted solid superacids; this technique provided a good indication of the activity of the bifunctional solid superacids. The activity of the Pt/ZrO(sub 2)/SO(sub 4) catalyst at 160(degrees)C was compared with a Pt/(gamma)-Al(sub 2)O(sub 3) reforming catalyst at 160(degrees)C and also at 400(degrees)C (350 psig H(sub 2)), respectively. The Pt/(gamma)-Al(sub 2)O(sub 3) catalyst was not effective at 160(degrees)C but gave a 6.2 wt% conversion of the n-hexadecane to isomerized and cracked products at 400(degrees)C. The isomerization and hydrocracking of long-chain paraffins over metal-promoted solid superacids were carried out in the presence of selected aromatic compounds. It appears that the presence of aromatics changes the surface acidity of the catalyst, resulting in higher molecular weight products (from C(sub 4)(minus)C(sub 9) to C(sub 10)(minus)C(sub 16)) from n-hexadecane. This finding is important in obtaining a more desirable product distribution from hydrocracking of F-T waxes.

REPORT  NUMBER: DOE/PC/91304-T8

CONTRACT  NUMBER: FG22-91PC91304