Hydroisomerization performance of platinum supported on ZSM-22/ZSM-23 intergrowth zeolite catalyst

Abstract

The typical physicochemical properties of these catalysts were characterized by X-Ray Diffraction (XRD), N 2 absorption-desorption, Pyridine-Fourier Transform Infrared (Py-FTIR), Transmission Electron Microscopy (TEM), X-Ray Fluorescence (XRF), Scanning Electron Microscopy (SEM) and NH 3-Temperature Programmed Desorption (NH 3-TPD), and the performance of these catalysts in n-dodecane hydroisomerization was evaluated in a continuous down-flow fixed bed with a stainless steel tubular reactor. The characterization results indicated that the intergrowth zeolite ZSM-22/ZSM-23 possessed the dual structure of ZSM-22 and ZSM-23, and the catalyst Pt/ZSM-22/ZSM-23 had similar pores and weak acidity to Pt/ZSM-22 and Pt/ZSM-23 catalysts. Moreover, Pt/ZSM-22/ZSM-23 catalyst showed a high selectivity in hydroisomerization of long chain n-alkanes to mono-branched isomers. The evaluation results for n-dodecane hydroisomerization indicated that the activity of Pt/ZSM-22/ZSM-23 was the lowest, while the hydroisomerization selectivity was the highest among the three catalysts. The maximum yield of i-dodecane product was 68.3% over Pt/ZSM-22/ZSM-23 at 320 ºC.

Catalytic Hydroisomerization of Long-Chain Hydrocarbons for the Production of Fuels

“…Another option to enhance the aluminum presence on the external zeolite (ZSM-22) surface, is to use ethanol as a co-solvent in hydrothermal zeolite synthesis [36], leading to the formation of ZSM-22 nano-bundles. These particles exhibited, according to 27 Al 2D 3Q MAS NMR, more aluminum that was located on the T1, T2, and T3 sites than a conventional ZSM-22. This result was interpreted by the oriented fusion of nanorods, as promoted by the presence of ethanol and formation of new micropores.…”

“…Composite materials and hierarchical zeolites have been prepared in order to increase the mass transfer inside zeolites. Several methods exist for preparation of hierarchical zeolites, such as dual templating [25,36], desilication via alkali treatment [35], dealumination via acid treatment [25], and synthesis of composite materials such as intergrowth micro/mesoporous ZSM-22/ZSM-23 (Table 3) [27]. Agglomeration of zeolites can be suppressed via their alumination, which was performed in [9,10].…”

Deactivation and regeneration of Pt‐modified zeolite Beta–Bindzil extrudates in n‐hexane hydroisomerization

“…Several studies on C 7 –C 16 n ‐alkane hydroisomerization used crushed shaped Pt catalysts (0.1–0.8 mm) with Pt deposition on either the shaped supports 1,2,40,41 or on a zeolite 1,2,21,42 . However, detailed studies of the uncrushed shaped bifunctional catalysts are still lacking in the open literature 2,3 .…”

Catalytic Hydroisomerization Upgrading of Vegetable Oil-Based Insulating Oil

“…Chi Kebin et al [53] investigated the performance of platinum supported on ZSM-22/ZSM-23 zeolite mixtures as hydroisomerization catalysts. The ZSM-22/ZSM-23 zeolites were prepared to have a uniform needle-shaped particle size from spindle-shaped ZSM-22 and nest-shaped ZSM-23.…”