Improving Plasma Regeneration Conditions of Pt–Sn/Al2O3 in Naphtha Catalytic Reforming Process Using Atmospheric DBD Plasma System

Abstract

The catalytic naphtha reforming is one of the largest processes of petroleum industry that is used to rebuild the low-octane hydrocarbons in the naphtha to more valuable high-octane gasoline called reformate without changing the boiling point range. An atmospheric pressure pin to plate dielectric barrier discharge (DBD) plasma was used to remove carbonaceous contaminant from the coked Pt-Sn/Al 2 O 3 catalysts during the naphtha reforming process. The effects of treatment time and flow ratios of O 2 /Ar and O 2 / He on the carbon content of the coked catalysts were investigated. The produced radicals and active species of the plasma process were identified by optical emission spectroscopy. To confirm removing the coke from the catalyst, thermal gravimetric/differential thermal analysis and temperature programmed oxidation analysis were done. Effects of treatment time and flow ratios of O 2 /Ar and O 2 /He on the carbon content of the coked catalysts were investigated by applying elemental analysis. The results of X-ray diffraction, X-ray fluorescence, Brunauer-Emmett-Teller, and CO adsorption showed that the structure and specifications of regenerated catalysts remained without significant changes during the plasma treating. The catalyst performance test revealed that DBD plasma regenerated catalysts increased the aromatic content of the feed as well as the fresh catalysts. The results showed that the plasma treatment method for regeneration of Pt-Sn/Al 2 O 3 can be applied at lower temperature and pressure relative to the thermal regeneration method.

Cold plasma treatment of catalytic materials: a review

“…In addition to preparing catalytic materials with high activity and stability, it is important to regenerate the deactivated catalytic materials to decrease the cost in chemical engineering. The deactivation of catalytic often occurs in heterogeneous catalytic reaction processes, such as abatement of volatile organic compounds (VOCs) [33,35], synthesis of NH 3 [311], hydroprocessing of CCl 4 [312], oxidative coupling of methane (OCM) [40], nitrobenzene hydrogenation [313] naphtha reforming [37], etc. Poisoning by strong chemisorption of reactants or products, coke formation by cracking/condensation reactions, and sintering of active components are the main sources of catalytic materials deactivation.…”

“…Research on the regeneration of catalytic materials has been explored for decades. The currently applied regeneration methods include supercritical fluid extraction (SFE), thermal treatment, etc [37]. High temperature or high pressure used for the regeneration of catalytic materials bring kinds of negative effects, such as agglomeration of active species, destruction of support structure, and segregation of different metals, etc.…”

“…On the other hand, the influence of cold plasma on the contact behavior at the mesoscopic scale makes the structure of the catalytic materials different from those obtained by conventional methods. Therefore, cold plasma treatment has been proved to be a fast, environmentally friendly and efficient method for reduction [22][23][24][25][26], deposition [27], combination [23,27,28], decomposition [1], modification [27][28][29][30], doping [2,[26][27][28][29][30][31], etching [27][28][29][30][31], exfoliation [2,28] and regeneration [32][33][34][35][36][37][38][39][40][41] of catalytic materials. The plasma strategies (usually occurred simultaneously) for catalytic materials treatment to improve their performance can be accomplished by increasing the surface area and the number of active sites, modulating the crystal structure, as well as by modification, doping, and vacancy engineering [2,29,42].…”

Plasma Catalytical Reactors for Atmospheric Gas Conversions

“…4), to increase the discharge gap, avoiding spark formation and form a non‐uniform dielectric field, resulting in lower operation voltage and lower dielectric loss . This combination results in several reactors as the (multi)needle‐to‐plane DBD , (multi)tubular‐to‐plane DBD , pin‐to‐plane DBD or wire‐to‐plane DBD. However, most of this corona DBD setups are currently used for plasma‐alone experiments.…”

Establishing the Appropriate Conditions of Regeneration of Cataytic Reforming Pt/AL<sub>2</sub>O<sub>3</sub> Catalyst

“…The major goal of catalyst regeneration is to restore the catalyst to almost its fresh activity state where metal and acid sites are functioning as before coke deposition. To achieve this goal, the catalyst coke is burned off in a controlled manner, platinum and promoter metals are redispersed, and catalyst chloride is restored either to a fresh catalyst level or to a prescribed regenerated catalyst chloride level [10].…”