Role of the Ru and Support in Sulfided RuNiMo Catalysts in Simultaneous Hydrodearomatization (HDA), Hydrodesulfurization (HDS), and Hydrodenitrogenation (HDN) Reactions

Abstract

Simultaneous hydrodesulfurization (HDS), hydrodearomatization (HDA), and hydrodenitrogenation (HDN) reactions have been studied over sulfided RuNiMo/Al 2 O 3 catalysts. The effects of Ru promotion and alumina support modification with HY zeolite and P on catalyst performance have been studied using a synthetic feed containing dibenzothiophene, toluene, naphthalene, and pyridine. Activity tests were carried out in a semiautomatic microplant equipped with a continuous flow reactor, working under conditions similar to industrial practice (P ) 5 MPa, T ) 285-360 °C, and liquid hourly space velocity (LHSV) ) 3 and 4.5 h -1 ). The catalysts were characterized by S BET , X-ray diffraction (XRD), temperature-programmed reduction (TPR), temperature-programmed desorption of ammonia (TPD-NH 3 ), and X-ray photoelectron spectroscopy (XPS) techniques. Activity tests revealed that optimal Ru loading is 1 wt % (nominal). Under fixed experimental conditions (300 °C, 5 MPa, and LHSV ) 3 h -1 ), ultra-low sulfur diesel (S < 20 ppm S) was obtained over a Ru(1%)Ni(5%)Mo(14%)/γ-Al 2 O 3 catalyst from a feed containing 18361 ppm S. However, this catalyst showed similar capability toward aromatics and pyridine removal as a commercial NiMo/Al 2 O 3 catalyst. At a reaction temperature of 345 °C, the 5% HY-Al 2 O 3 substrate led to a small increase in the hydrogenation capability of this catalyst but without enhancement of its HDS/HDN capability. On the contrary, the P-modified substrate resulted in a lower activity. The properties of the supported catalysts are discussed in terms of the support effect and Ru promotion.

Catalytically Active Sites of Supported Pt Catalysts for Hydrogenation of Tetralin in the Presence of Dibenzothiophene and Quinoline

“…Especially, hydrodearomatization (HDA) is aimed to reduce the concentration of aromatics in the fuel to fulfill the tightened requirements for ultraclean diesel. Oxide-supported noble metal catalysts are well-known for their high hydrogenation activities in deep HDA. − This includes also bimetallic catalysts containing combinations of Pt, Pd, Rh, Ru, and Re. However, such noble metals exhibit a low resistance toward sulfur and nitrogen poisons, which are usually present in the feedstocks …”

Effect of Nitrogen Compounds on Reactive Adsorption Desulfurization over NiO/ZnO-Al2O3-SiO2 Adsorbents

“…Nitrogen-containing compounds may affect the adsorption of sulfur compounds on the active sites, leading to coke deposition, which decreases desulfurization efficiency . Many researches focus on the competitive adsorption between sulfur and nitrogen compounds on nickel based catalyst. − This is the key factor for the inhibiting effects on the HDS of sulfur compounds. , Basic nitrogen compounds, such as quinoline, are stronger inhibitors for the HDS reactions than the nonbasic moieties, such as indole. − Besides nitrogen compounds, Huang et al , investigated the RADS mechanism on Ni/ZnO and the competition between RADS of dibenzothiophene (DBT) and hydrogenation of naphthalene over Ni/ZnO. They found that naphthalene inhibited the RADS of DBT, while DBT inhibited the hydrogenation of naphthalene.…”

“…14−20 This is the key factor for the inhibiting effects on the HDS of sulfur compounds. 21,22 Basic nitrogen compounds, such as quinoline, are stronger inhibitors for the HDS reactions than the nonbasic moieties, such as indole. 23−26 Besides nitrogen compounds, Huang et al 27,28 investigated the RADS mechanism on Ni/ ZnO and the competition between RADS of dibenzothiophene (DBT) and hydrogenation of naphthalene over Ni/ZnO.…”

Synergetic effect in RuxMo(1-x)S2/SBA-15 hydrodesulfurization catalysts: Comparative experimental and DFT studies

“…Since the pioneering work by Pecoraro and Chianelli [4], the catalysts based on RuS2 demonstrated to be one of the most effective catalytic systems for desulfurization processes [5][6][7][8][9][10][11][12][13][14][15][16][17][18]. The high HDS activity of the monometallic RuS2/Al2O3 catalyst was ascribed to easy stabililization of the sulfur species upon reaction conditions employed and high intrinsic hydrogenation activity of Ru [9].…”

“…The high HDS activity of the monometallic RuS2/Al2O3 catalyst was ascribed to easy stabililization of the sulfur species upon reaction conditions employed and high intrinsic hydrogenation activity of Ru [9]. Indeed, the enhancement of the HDS activity and selectivity toward hydrogenation route products was observed after Ru incorporation into a commercial Ni(Co)Mo/Al2O3 sulfide catalysts [10][11][12][13][14].…”