Hydrocracking vegetable oil on borate-containing catalysts: Effect of nature of support

• Published in: Kinetics and catalysis 2017, Vol.58 (5), p.563-576
• Main Authors: Chumachenko, Yu. A., Trenikhin, M. V., Talzi, V. P., Gulyaeva, T. I., Paukshtis, E. A.
• Format: Article
• Language: English
• Subjects: Alkanes; Aluminum oxide; Boron oxides; Catalysis; Catalysts; Chemical reactions; Chemistry; Chemistry and Materials Science; Cycloalkanes; Decarboxylation; Dehydration; Diesel; Feed rate; Hydrocarbons; Hydrocracking; Hydrogenation; Physical Chemistry; Platinum; Scholarships & fellowships; Zirconium dioxide
• ISSN: 0023-1584; 1608-3210
• DOI: 10.1134/S0023158417050032

The structure, texture, and acid properties of platinum catalysts on oxide (Al 2 O 3 , ZrO 2 , ZrO 2 –Al 2 O 3 ) and borate-containing supports (B 2 O 3 –Al 2 O 3 , B 2 O 3 –ZrO 2 ) are studied. The catalysts are tested in the process of hydrocracking sunflower-seed oil at 380°C, 4.0 MPa, and a weight stock feed rate of 1.0 h –1 . It has been found that aluminum oxide (A) contains the γ-Al 2 O 3 phase, zirconium dioxide (Z) includes 85 and 15 rel. % of the monoclinic (M) and tetragonal (T) phases, respectively, while zirconium dioxide with the addition of 2.5 wt % Al 2 O 3 (ZA) comprises 14 and 86 rel. % of the M–ZrO 2 and T–ZrO 2 phases, respectively. The B 2 O 3 –Al 2 O 3 (BA) and B 2 O 3 –ZrO 2 (BZ) systems modified with boron oxide (20 wt %) are X-ray amorphous. A Pt/BA catalyst differs from a Pt/A catalyst, while a Pt/BZ catalyst has a larger specific surface area and acidity than Pt/Z and Pt/ZA catalysts and contains Bronsted acidic centers (BACs) along with Lewis acidic centers (LACs). Only LACs are present on the surface of Pt/A, Pt/Z, and Pt/ZA catalysts. The LAC/BAC ratio in Pt/BA and Pt/BZ catalysts is 0.3 and 1.0, respectively. All the catalysts provide complete oil conversion to give C 5+ hydrocarbons with a yield of 81.7–87.3 wt %. Pt/A catalyzes mainly decarboxylation and hydrogenation–dehydration reactions, while Pt/Z and Pt/ZA provide decarboxylation. The yield of diesel fraction reaches 71.8–73.9 wt % with an n-alkane content of 94.0–95.9 wt %. One-stage oil hydrocracking with the prevalence of hydrodecarbonylation and hydrogenation–dehydration reactions occurs on Pt/BA and Pt/BZ catalysts for 20 h to give the yield of the diesel fraction of at least 81.4 and 74.4 wt % and the total content of iso -alkanes and cycloalkanes of at least 28.3 and 60.7 wt %, respectively.