Hydro-conversion of 1-methyl naphthalene into (alkyl)benzenes over alumina-coated USY zeolite-supported NiMoS catalysts

Abstract

Hydro-conversion reactions were carried out at 360°C under 5 MPa of H 2 pressure to study ring-opening reactions of 1-methyl naphthalene using NiMoS supported on γ-alumina and alumina-coated/mixed USY zeolites. The catalysts were characterized using N 2-BET, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), pyridine FT-IR, and high-resolution transmission electron microscopy (HRTEM) to study the influence of morphological and acidic properties on hydrogenation (HYD) and hydrocracking (HC) reactions. NMACZ-2 (NiMoS supported on the minimum amount of alumina-coated USY zeolite) showed enhanced reactivity for HC and produced (alkyl)benzenes with the highest yield, of ca. 80%. By-products were tetralin, decalin and cyclo-paraffin species. The tetralin species produced using NMACZ-2 moved into the alumina-coated USY zeolite support before undergoing HYD to produce decalin species, which were rapidly and selectively hydro-cracked into (alkyl)benzenes. A large amount of decalin was produced through the HYD of tetralin without significant cracking, possibly due to the weak acid character of γ-alumina. Bulk-phase Mo oxide species on NMAZ (physical mixture of alumina and USY zeolite), as well as deactivation of the catalysts due to coke formation over the naked zeolite surface, inhibited the ring opening of tetralin, decreasing the yield of (alkyl) benzene. 3 Various morphologies, such as the MoS 2 structure and acidic characteristics of the catalysts, were crucial factors affecting the HC reactivity of 1-methyl naphthalene.

Optimization of catalytic hydrodeoxygenation of oleic acid into biofuel using fluoroplatinum oxalate zeolite supported catalyst

“…In this direction, several studies such as effects of different catalyst supports [9,11] and types of metals [12,13], catalyst preparation procedure [14,15] and additives such as sulfur [16] and phosphorus [17] are currently receiving attentions. Among all the catalyst supports studied, zeolites appeared to be more interesting and promising owing to their crystalline structure, well-defined pore shapes and sizes which allow tweaking of catalytic properties and performance [12].…”

Mild hydrocracking of 1-methyl naphthalene (1-MN) over alumina modified zeolite

“…In contrast, alumina-coated zeolite carries the highly dispersed NiMoS as well as the strong acidity, which is induced by the underlying zeolite layer, on the single alumina surface. In an earlier publication, alumina-modified USY zeolite for the hydrocracking of 1-MN as a model compound in LCO has been proposed by the present authors [13], in which the selective hydrocracking activity of NiMoS supported on the alumina-coated USY zeolites varies with their coating amounts as illustrated in Fig. 1, since the thickness of alumina coating controls the balance between acidity and hydrogenation activity.…”

“…The synthetic method of the catalysts was well summarized in the previous study [13]. The amounts of nickel and molybdenum oxide loaded on these supports were controlled at 5 and 20 wt%, respectively, in both the catalysts.…”

“…Based on the above points, the alumina modified USY zeolite (NMACZ series) was synthesized by the authors in association with JGC-CCIC to compare it with the physical mixture of alumina/USY zeolite catalyst (NMAZ) [13]. The representative results (Table 3) show that NMAZ catalyst with stronger acidity lead to lower yields of (alkyl)benzenes and higher light products through excesscracking over the exposed acidic sites of zeolite.…”

Effect of precursor acidity on zeolite supported Pd catalyst properties and hydrodeoxygenation activity for the production of biofuel

“…The comparably severe loss of crystallinity in the FPd/Z catalyst compared toPd/Z earlier observed in the SEM and XRD results which gave rise to its comparably higher Si/Al ratio (Table 1) Recently in attempt to gain thorough insight into the hydrodeoxygenation (HDO) process of different feed stocks, studies onreaction variablessuch as effects of reaction pressure and temperature, H 2 gas flow rate, catalyst loading and even types of reactors and mode of operations have been well studied and reported [20,[30][31][32][33][34]. However, since existing hydrotreating units of conventional crude oil refineries can be adapted for the HDO process of biofuel production, studies on expedient synthesis of suitable catalysts such as types of the support and metals [34], systematic catalyst preparation procedure [20,26,35]and additives such as sulfur [36]and phosphorus [31]are currently receiving attention.In this direction, we recently, functionalized nickel with oxalic acid and supported on alumina for the hydrodeoxygenation of oleic acid into high grade biofuel [18]. At the best operational conditions of 20 bar, 360 ºC and 100 ml/min of gas flow, the catalystshowed superior activities to other alumina supported Ni catalysts in literature.…”