Hydroisomerization of n-Heptane in a Fixed-Bed Reactor Using a Synthesized Bimetallic Type-HY Zeolite Catalyst

Khalaf, Younus H.; Sherhan, Bashir Y.; Shakour, Zaidoon M.

doi:10.30684/etj.2022.132491.1124

	Hydroisomerization of n-Heptane in a Fixed-Bed Reactor Using a Synthesized Bimetallic Type-HY Zeolite Catalyst
Engineering and Technology Journal
Article 5, Volume 40, Issue 9, September 2022, Pages 1158-1170 PDF (1.36 M)
Document Type: Research Paper
DOI: 10.30684/etj.2022.132491.1124
Authors
Younus H. Khalaf^* ¹; Bashir Y. Sherhan²; Zaidoon M. Shakour¹
¹Chemical Engineering Department, University of Technology-Iraq
²Chemical Engineering Department, University of Technology - Iraq
Abstract
The synthesis of NaY-zeolite was performed hydrothermally. The preparation of the bifunctional catalysts was achieved by loading NH₄Y-zeolite with a cheap Zr metal, as a second loading metal, with tiny amounts of Pt to compose a Pt-Zr/Y-zeolite catalyst. Different characterization methods (i.e., XRD, SEM, EDX, BET, and AFM) were used to investigate the catalyst properties. The catalytic performance was studied by performing the hydroisomerization of n-heptane in a gas phase at a temperature of 275°C and atmospheric pressure in a fixed-bed reactor. The GC-FID results of the products confirmed the positive role of Zr in enhancing the catalytic features, as reflected by the increase in the isomerized products and the decrease in the unwanted by-products. Incorporating 1.0wt%Zr with 1.0wt% of Pt significantly improved the activity and selectivity and increased the yield of branched alkanes. This was achieved because the addition of zirconium provided an extraordinary Lewis acidity to the zeolite-framework structure and simultaneously took advantage of the electronic and catalytic properties of Zr and Pt metals to enhance its novel catalytic features. This reduced the amount of Pt metal and halved the cost of the catalyst. In addition, the bimetallic catalyst (HY-zeolite loaded with 1wt%Pt & 1wt%Zr) achieved values of 74.2, 78.8, and 58.5mol% for conversion, selectivity, and yield, respectively. The conversion was improved to a level close to 2wt% Pt/HY-zeolite catalyst, while selectivity was not significantly decreased from that of 2wt% Zr/HY-zeolite catalyst, reaching a yield level of isomers close to that of 2wt% Pt/HY-zeolite catalysts.
Highlights
The synthesis of NaY-zeolite by the hydrothermal method. Modification of NaY to form NH₄Y, HY, and Metal-Loaded-HY-Zeolites by incipient wetness impregnation method The preparation of the bimetallic catalyst depends on the two metals Zr and Pt. Performing the hydroisomerization of n-heptane and proving the novel catalyst (1wt% Pt with 1wt% Zr)/ HY-Zeolite is an active and selective catalyst. The amount of the costly Pt metal in the catalyst depends on the cheap Zr Metal was decreased.
Keywords
Bimetallic; Isomerization; Octane, Platinum Synthesis; Zirconium

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