Aluminosilicates supported La-containing sulfur reduction additives for FCC catalyst: Correlation between activity, support structure and acidity

Accepted Manuscript Title: Aluminosilicates supported La-containing sulfur reduction additives for FCC catalyst: correlation between activity, support structure and acidity Authors: Aleksandr Glotov, Nikolai Levshakov, Anna Vutolkina, Sergey Lysenko, Eduard Karakhanov, Vladimir Vinokurov PII: DOI: Reference:

S0920-5861(18)31062-9 https://doi.org/10.1016/j.cattod.2018.10.009 CATTOD 11672

To appear in:

Catalysis Today

Received date: Revised date: Accepted date:

16-7-2018 3-10-2018 8-10-2018

Please cite this article as: Aleksandr Glotov, Nikolai Levshakov, Anna Vutolkina, Sergey Lysenko, Eduard Karakhanov, Vladimir Vinokurov, Aluminosilicates supported La-containing sulfur reduction additives for FCC catalyst: correlation between activity, support structure and acidity, Catalysis Today https://doi.org/10.1016/j.cattod.2018.10.009 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.

Aluminosilicates supported La-containing sulfur reduction additives for FCC catalyst: correlation between activity, support structure and acidity Aleksandr Glotov*a,b, Nikolai Levshakova,b, Anna Vutolkinab, Sergey Lysenkob, Eduard Karakhanovb, Vladimir Vinokurova aGubkin

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Russian State University of Oil and Gas, Physical and Colloid Chemistry Department, Leninskiy prospect 65, Moscow, 119991, Russia bLomonosov Moscow State University, Chemistry Department, Leninskiye Gory 1-3, GSP-1, Moscow, 119991, Russia *Corresponding

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author: Aleksandr Glotov, e-mail: [email protected] Postal address: Gubkin Russian State University of Oil and Gas, Physical and Colloid Chemistry Department, Leninskiy prospect 65, Moscow, 119991, Russia

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Graphical abstract:

Highlights  Aluminosilicates based additives decrease sulfur content by 39 % than FCC catalyst;  Additives on Al-MCM-41, Al-SBA-15 are more active in sulfur removal than Al-SBA-16;  Modification by metals (Al, La) leads to increasing of acidity and sulfur removal.

Abstract

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Mesoporous silica oxides MCM-41, SBA-15 and SBA-16 were synthesized and modified to form aluminosilicates with Al/Si atomic ratio of 1/400. In order to improve thermal and mechanical stability the alumina phase was intercalated. The resulted Al-MCM-41/Al2O3, Al-SBA-15/Al2O3, Al-SBA-16/Al2O3 supports were impregnated with 5% lanthanum and tested as sulfur reduction additives to equilibrium microspherical zeolite–containing cracking catalyst (e-cat). The well-ordered pore arrangement and incorporation of alumina atoms into mesoporous framework were confirmed by X-ray diffraction (XRD), transmission electron microscopy (TEM) and 27Al solid-state magic angle spinning nuclear magnetic resonance (MAS NMR) spectroscopy. To compare the sulfur reduction activity with respect to the nature of the support, the textural properties and acidity were studied by low-temperature nitrogen adsorption/desorption (N2 adsorption/desorption) and temperature programmed desorption of ammonia (NH3-TPD) techniques. Catalytic cracking of vacuum gas oil (VGO) over e-cat mixed with mesoporous supported La additives (10 wt%) synthesized was carried out on a micro activity testing (MAT) laboratory unit at 500 °C and catalyst/feedstock weight ratio of 3.4 to compare the morphology of mesoporous structure and sulfur reduction activity. In order to assess the support effect on catalytic performance a comparative study of La/Al 2O3 and mesoporous La supported additives was carried out. Hydrothermal stability of additives was also studied by means of steaming procedure at the temperature of 700 °C (100 % steam) for 2 hours.

Keywords

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Sulfur removal, structured mesoporous aluminosilicates, FCC additives, catalytic cracking, vacuum gas oil, lanthanum.

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Nomenclature

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BET BJH CTMAB e-cat FCC HCO LCO MAS NMR MAT NH3-TPD TEM TEOS VGO XRD

Brunauer-Emmett-Teller Barrett-Joyner-Halenda cetyltrimethylammonium bromide equilibrium microspherical zeolite–containing cracking catalyst Fluid Catalytic cracking heavy cycle oil light cycle oil Solid-state magic angle spinning nuclear magnetic resonance micro activity testing temperature-programmed desorption of ammonia transmission electron microscopy tetraethyl orthosilicate vacuum gas oil X-ray diffraction

1. Introduction

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Due to the strong ecological restrictions for fossil fuels the demand for heavy oil feedstock refinery aimed at low-sulfur gasoline production has increased considerably [1, 2]. Hydrotreatment of FCC gasoline is widely used for production of eco-friendly transportation fuels with lower sulfur, nitrogen and benzene content [3, 4]. At the same time, FCC gasoline is one of the major sources of sulfur in gasoline pool [3]. In order to decrease sulfur content in gasoline fraction, sulfur reduction additives to catalysts can be used [4-7]. Its sulfur reduction activity depends on adsorption capacity for sulfur compounds which in turn provided by acidity of support [8-12]. The latter should also have thermal and mechanical stability. A number of researches are devoted to investigation of sulfur reduction activity of Al2O3 based additives [5]. Conventionally used Zn-Mg-Al spinels are not highly activity due to low concentration of Lewis acid sites [4, 6, 7]. The main disadvantages of these additives are decreasing of FCC gasoline fraction yields and high coke formation [6, 13]. Blending zinc or magnesium spinels based additives with commercial FCC increases Al2O3 and reduces the zeolite contents in catalytic system. This dilution provided by additives results in low conversion and decrease gasoline yield [14, 15]. The higher coke formation than the catalyst without additives may be connected with low hydrogen transfer activity. On the other hand, high Lewis acidity and activity of ZnAl2O4 additives in reduction of sulfur molecules from light cycle oil enhances coke yield also [3, 16]. Mesoporous silica oxides are promising support materials possessing an ordered mesoporous framework. Isomorphous substitution of silicon by aluminium leads to formation aluminosilicates characterized by high acidity and specific surface area providing high adsorptive capacity for sulfur compounds [9, 17]. Thanks to aluminium atoms included in the structure, these materials can generate Brønsted and Lewis acidity, so these modified supports can be used for acid-catalyzed reactions, such as isomerization and cracking [9, 18]. Besides, due to appropriate pore sizes excluding steric hindrances the mesoporous aluminosilicates are more resistant to pore blocking and long-lived catalysts and additives [19-21]. Incorporation of alumina atom into silica framework of mesoporous materials also leads to increasing a wall thickness resulting in higher thermal and mechanical stabilities of aluminosilicates formed [22, 23]. It was reported, that mesoporous based La-containing additives, thanks to high specific surface area and acidity, have a high adsorptive capacity for sulfur compounds [10]. It was assumed that interaction between lanthanum and oxygen bridging atoms leads to formation two hydroxide groups, thereby enhancing the number of Brønsted acid sites. So, sulfur organic compounds being Brønsted bases could be rapidly adsorbed and cracked [13,24]. In our previous researches the high sulfur reduction activity of metalcontaining MCM-41 and HMS based additives was shown [13, 25, 26]. It was proved that among La, W and Ni-containing additives the former has the highest sulfur reduction ability. Hydrothermal stability of MCM-41 supported La additives was also considered in detail [24]. Sulfur reduction activity of additives based on HMS mesoporous silica oxide supporting 5 % of La is similar to that of based on MCM-41. The highest sulfur reduction ability and gasoline yield were observed for the additive La/HMS/Al 2O3 with the carrier

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composition of 60/40 wt% [26]. We also have demonstrated the catalytic performance of Al-SBA-15, Al-SBA-16 and Al-MCM-41 supported Mg, Zn, La additives [23, 27]. The present research is devoted to testing La-containing mesoporous aluminosilicates Al-MCM-41, Al-SBA-15, Al-SBA-16 as components of sulfur reduction additives to FCC catalyst. The thermal and mechanical stability of these materials also can be achieved due to formation of alumina phase [28]. We combined two approaches previously described to create aluminosilicate based sulfur reduction additives characterized by high specific surface area, suitable acidity and high adsorption capacity for sulfur species. The structure, textural properties and acidity of mesoporous aluminosilicates affect on adsorption capacity but also influence on dispersion of active metal phase. Thus, in this study, the catalytic performance of Al-SBA-15, Al-SBA-16 and Al-MCM-41 supported La was investigated with respect to the effects of support morphology. 2. Materials and methods 2.1 Materials

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The properties of VGO using as a feedstock are summarized in Table 1.

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2.2 Additive preparation procedure

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A commercial equilibrium microspherical zeolite-containing cracking catalyst (e-cat) was used as a FCC catalyst. Table 2 summarizes its properties. Prior to testing, e-cat was calcined in air at 550 °C for 5 h.

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The mesoporous silica oxide was synthesized via the neutral templating pathway [28] using cetyltrimethylammonium bromide (CTMAB) as a surfactant (98%, “SigmaAldrich”), tetraethyl orthosilicate (TEOS) (≥98%, “Sigma-Aldrich”) as the silica source. CTMAB was dissolved in distilled water at the temperature of 35 °C, and the weighed portion of aqueous ammonia (25 wt%) was added to the solution. While stirring, TEOS was added slowly to the surfactant solution for 30 min, resulting in a gel with the molar composition 5SiO2:CTMAB:462H2O. The mixture was stirred for 4 h, and then aged at room temperature for 24 h. The white precipitate was filtered and washed with 200 ml of distilled water. The sample was dried at room temperature for 24 h, then at 110°C for 3 h, and at 350°C for 3 h. Calcination was carried out in static air at 650°C for 4 h to remove the template. Following the procedure [29], SBA-15 oxide silica was synthesized. Pluronic P123 was dissolved in aqueous solution of 1.6 M HCl at 30 °C and TEOS was added dropwise while stirring. Reaction mixture was stirring at 40 °C for 24 h. After this, resulted gel was placed in the autoclave and treated hydrothermally at 100°C for 24 h. The solid product was recovered by filtration, washed with deionized water and dried at 80 °C. The sample was calcined in air at 650 °C for 4 h to remove the template. For the synthesis of SBA-16 [30], the weighed portion of Pluronic F127 was dissolved in aqueous solution of 2 M HCl. While stirring the solution, TEOS was added dropwise. Reaction mixture was stirring at 40 °C for 2 h. After this, resulted gel was placed in the autoclave and treated hydrothermally at 80°C for 6 h. The white precipitate was

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washed by distilled water, filtered and dried at 80 °C. The sample was dried at 110 and 350 °C for 3 h respectively and calcined at 650 °C in air for 4 h to remove the template. Resulting silica oxide MCM-41, SBA-15 and SBA-16 were modified by aluminium isopropoxide according to the reported procedure [28]. The aluminosilicates were formed with pseudoboehmite using 1M nitric acid solution followed by calcination at 550°C for 3 h. Resulting Al-MCM-41/Al2O3, Al-SBA15/Al2O3, Al-SBA-16/Al2O3 materials were used for preparation of La-containing additives via incipient wetness impregnation technique. To incorporate of 5 wt% of La the calcined supports were impregnated using La(NO3)3 aqueous solutions. The materials were dried in air at room temperature for 8 h, then at 110 °C for 12 h and calcined at 650 °C for 4 h. 2.3 Characterization techniques

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The isotherms of nitrogen adsorption/desorption at 77 K were measured on the Micromeritics Gemini VII 2390t instrument. Before the measurements, the samples were degassed at temperature of 350 °C for 6 h. The specific surface area was calculated using the Brunauer–Emmett–Teller (BET) method in the range of relative pressures P/P0 = 0.05–0.30. The pore volume and pore size distributions were determined from the adsorption branches of the isotherms based on the Barrett–Joyner–Halenda (BJH) model. TEM microscopy studies of mesoporous supports and La-containing additives were carried out using a JEM-2100 JEOL microscope operating with a 100 kV accelerating voltage. X-ray diffraction (XRD) data were obtained at room temperature on a Bruker D2 PHASER powder diffractometer in the θ–θ geometry with X-ray generation at 30 kV and 10 mA using a copper anode (λ(CuKα) = 1.5418 Å). Diffraction patterns were recorded with sample rotation in the horizontal plane in the angle interval of 2θ of 1.5° to 8° using a step size of 0.05° and 3 s per step. The diffraction patterns were processed using the Bruker software package diffrac.EVA. Identification of phases was carried out on the basis of ICDD. The acidity of the mesoporous aluminosilicates and La-containing additives was determined by the temperature-programmed desorption of ammonia (NH3-TPD) measurements carried out with the Micromeritics AutoChem HP Chemisorption Analyzer. The temperature was raised up to 800°C with heating rate 10°C/min. In order to determine quantity of desorbed NH3 and total acidity of materials TPD-NH3 data was analyzed with AutoChem HP V2.04. Solid-state magic-angle spinning nuclear magnetic resonance (MAS NMR) 27Al spectra were recorded using a Varian Unity Inova Plus AS500 spectrometer and a 7.5mmT3 HXY probe; the sample rotation frequency was 4.5 kHz, and aluminum chloride were used as standard reference substances. Lanthanum content in additives was determined by ARL QUANT'X EDXRF Spectrometer (Thermo Scientific) with a standard-less analysis method UniQuant. 2.4 Catalytic activity measurements The MAT procedure is one of the most common methods for FCC catalysts testing. Due to reproducibility of results and low cost, great amount of FCC catalysts and additives evaluations were performed using ASTM procedure D-3907 [4, 5, 16].

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Catalytic cracking experiments were performed using MAT-unit with a fixed bed reactor corresponding to the ASTM procedure D3907 [31]. Feed (1.3 g) was injected for 75 s at 500 °C. Mixture of e-cat and additive (mass ratio of 10/1) was used as a catalytic system. Weighted hourly space velocity was 15.6 h-1. Results for all testing additives were compared with those for e-cat used as a reference. The liquid fraction was collected, weighed and analyzed by a simulated distillation method according to ASTM procedure D2887 [32], on a gas chromatograph “Chromos GC-1000” with capillary column MXT-2887 (10m*0,53mm*2,65µm) and FID equipped. The analysis conditions are presented in Table 3. Depending on boiling points, the liquid products were separated into three fractions of gasoline (50–196 °C), light cycle oil (LCO) (196–300 °C), and heavy cycle oil (HCO) (300 °C+). The measurement error in determining the fraction composition was 1 wt%. The concentration of sulfur in the liquid products was determined on a Spektroskan S energy-dispersive X-ray fluorescence analyzer with an error of 50 ppm. The coke content of the catalyst was determined by gravimetry with an error in 1 wt%. Yields of liquid fractions W (%wt) were calculated as follows: 𝑊 = (𝑚 ∗ 𝑠)⁄𝑚𝑓 where m – mass of liquid products (g), s – mass content of fraction in liquid products (%wt), mf – mass of feed (g), mf=1.3 g. The yield of coke Sc (%wt) was calculated according to the following formula: 𝑚𝑐𝑎𝑡 − 𝑚𝑏𝑐𝑎𝑡 𝑚𝑐𝑎𝑡+𝑎𝑑𝑑 𝑆𝑐 = ∗ ∗ 100% , 𝑚𝑐𝑎𝑡 𝑚𝑓 where mcat – mass of coked catalyst with additive after reaction (g), mbcat – mass of coked catalyst with additive after coke burning (g), m cat+add – mass of catalyst with additive (g), mcat+add=4.0 g The yield of gaseous products Sg (wt %) was obtained from the equation: Sg=100 % - Sl - Sc, where Sl – yield of liquid products (wt%), Sc – yield of coke (wt%). Steaming procedure The steaming procedure of La/Al-MCM-41/Al2O3 was performed at the temperature of 700 °C (100 % steam) for 2 h. Experiments were performed in the stainless steel fixed bed unit heated by a 3-zone furnace. During the procedure 10 ml of water were injected. Temperature was controlled by the internal thermocouple.

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3. Results and discussions At first, mesoporous silica oxides were synthesized according to the Scheme 1. Next, isomorphous substitution of Si4+ by Al3+ cations by the post-synthesis treatment was performed resulted in aluminosilicates with atomic Si/Al ratio of 400/1 formation. According to the [28] this Si to Al atomic ratio is enough for increasing acidity saving ordering structure of mesoporous silica oxide that leads to high specific surface area. Simultaneously such trace amount of Al could give a material with high hydrothermal stability. To obtain Al-MCM-41/Al2O3, Al-SBA-15/Al2O3, Al-SBA-16/Al2O3 supports with component mass ratio of 60/40 aluminosilicates were formed with pseudoboehmite using

1M nitric acid solution followed by calcination. After this, La impregnation was carried out by standard incipient wetness impregnation technique using aqueous solutions of La(NO3)3 Thus, FCC additives La/Al-MCM-41/Al2O3, La/Al-SBA-15/Al2O3 and La/Al-SBA16/Al2O3 with the particle size in the range of 120-250 μm were obtained.

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The formation of mesoporous framework was confirmed by N 2 adsorption/desorption, BET, TEM, and XRD methods. Incorporation of alumina atoms was proved by 27Al MAS NMR, which reveal the coordination of Al atoms in the samples. The spectra of the aluminosilicates record the signal at 55.3 ppm corresponding to tetrahedral aluminum atoms [33], whereas the signal at 0 ppm could be related to octahedral extra framework Al species (Fig. 1S). The low-angle X-ray diffraction patterns of naked Al-MCM-41 and Al-SBA-15 supports are shown in Fig. 1.

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According to XRD data silica oxide mesoporous structure didn’t collapse after modification with aluminium isopropoxide resulted in aluminosilicates formation. The AlMCM-41 sample had well defined (100), (110) and (200) reflections corresponding to hexagonal structure. On the other hand, the XRD patterns of Al-SBA-15 sample had defined reflections at 2 and 2.9 2θ degrees corresponding to formation of SBA-15 type material with a cubic structure [34, 35]. By means of elemental analysis lanthanum content was 4.83, 4.56 and 4.78 wt% for Al-SBA-16, Al-SBA-15 and Al-MCM-41 based additives respectively. The textural properties of the supports and La-containing additives were studied by low-temperature N2 adsorption/desorption. The N2 isotherms for all samples are of type IV. The N2 isotherms have capillary condensation step in range of relative pressure between 0.4-0.8 indicating the presence of mesoporous framework (Fig. 2).

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The shapes of the isotherms for additives are similar to those of the silica, indicating that the porous characteristics of the supports have not been damaged during both alumina incorporation and La loading. Textural properties of supports and additives are listed in Table 4.

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Both SBET and Vpore decrease after metal oxide incorporation during additives preparation. Regardless of the support, all additive samples have a high value of S BET about 400-500 m2/g. Decreasing of Vpore after metal loading suggests the loss of mesoporosity, which is probably due to formation of La-oxides into pores. The pore volumes for La/Al-SBA-15/Al2O3 and La/Al-SBA-16/Al2O3 are very similar (0.42 and 0.43 cm3/g respectively), but the pore diameter of Al-SBA-16 based additives is much lower than that of Al-SBA-15 supported (36 vs 49 Ǻ). It can be explained by different pore structures of silica oxides. SBA-16 substrate has a three-dimensional channel system and uniform-size pores of a super large cage-like structure with a cubic symmetry. SBA16 is known to contain micropores within the walls of primary mesopores forming a threedimensional channel system with connections between the mesopores. SBA-15 and MCM-41 characterized by 2-D hexagonal porous arrangement.

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Calcined aluminosilicates and La-containing additives have a well-ordered porous arrangement as depicted on TEM micrographs that indicate the porous structure of the support remains the same after metal loading followed by calcination. According to the data obtained (Fig. 3), mesoporous structure of silica oxides was kept after modification. The ordered structure of pores and channels can be seen from microphotographs. The acidity of supports and mesoporous based La-containing additives was measured by NH3-TPD method. The acid sites distribution pattern was classified as weak, medium and strong depending on the temperature ranges where ammonia is being desorbed. The concentration of acid sites (in μmol NH3 desorbed per gram) is summarized in Table 5.

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The incorporation of La leads to increasing total acidity of additives. As seen in Table 5, the observed trend for the weak and total acid sites for both mesoporous materials and La additives was as follows: Al-SBA-16/Al2O3
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It is worth mention, that not perfectly linear correlation could be explained by different acidity of the test materials, but also affected by pore structure of supports. It could be also related to textural properties (pore diameter and pore volume) influenced on accessibility of the sulfur compounds to achieve the active acid sites. Thus, pore diameter of La/Al-SBA-16/Al2O3 is too small (37 Ǻ), while for Al-SBA-15 based additives the value is 46 Ǻ. The most active La/ Al-MCM-41/Al2O3 additive has an average Dpore 40 Ǻ approving some molecules to go through pores without adsorption. Besides, the 2-D pore system of Al-MCM-41 is preferable for bulky molecules diffusion achieving active sites.

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The 2-D hexagonal arrangement of pore system of the Al-SBA-15 material might provide more favorable mass transfer kinetics than the 3-D pore arrangement of Al-SBA16 leading to cracking sulfur organic compounds under FCC conditions. In some degree, the diffusion limitations could be also caused by some extent pores blocking of the support or loss mesoporosity during metal loading confirmed by decrease of Dpore according to N2 adsorption/desorption data. Along with enhanced sulfur reduction activity, the additives also affect on products distribution. The gasoline yields using additives decrease according to the following trend: La/Al2O3
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It is well known that FCC catalysts affected by steaming during coke burning in regenerator at high temperature [37]. Incorporation of alumina atom into silica framework of mesoporous materials also leads to increasing a wall thickness resulting in higher thermal and mechanical stabilities of aluminosilicates formed [22]. The thermal and mechanical stability can be also achieved due to formation of alumina phase [13, 28]. In order to evaluate stability of the mesoporous based La-containing additives steaming treatment having performed at the temperature of 700 °C (100 % steam) for 2 h. As Fig.6 shows, this treatment destroys mesoporous structure. The specific surface area of mesoporous based additive decrease to 46 m2/g according to low-temperature N2 adsorption/desorption. The N2 isotherms of steamed sample are of type II, indicating the presence of alumina phase (Fig.6). The nitrogen

consumption also decreases within the shift of the inflection point of its hysteresis to higher value of the relative pressure (from 0.4 to 0.6 P/P0).

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4. Conclusions According to data above, additive based on Al-MCM-41/Al2O3 is more effective than its Al-SBA-15 and Al-SBA-16 counterparts providing decrease of sulfur content in liquid products on 39% comparing to e-cat. The more the total amount of desorbed ammonia, the higher sulfur reduction activity follows the trend: La-Al-SBA-16/Al2O3
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Acknowledgments This work was financially supported by Russian Science Foundation (project №17-79-

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10301). Authors thank V.D. Stytsenko for his contribution in this work.

References [1] Y. Wen, G. Wang, C. Xu, J. Gao, Energ. Fuel. 26 (2012) 3201-3211. [2] Z. Klimint, S.J. Smith, J. Cofala, Environ. Res. Lett. 8 (2013) 014003. [3] X. Pang, L. Zhang, S. Sun, T. Liu, X. Gao, Catal. Today 125 (2007) 173-177. [4] R. Feng, H. Al-Megren, X. Li, M.C. Al-Kinany, K. Qiao, X. Liu, Z. Yan, Appl. Petrochem. Res. 4 (2014) 329-336. [5] P.F. Andersson, M. Pirjamali, S.G. Järås, M. Boutonnet-Kizling, Catal. Today 53 (1999) 565-573.

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[6] T. Myrstad, H. Engan, B. Seljestokken, E. Rytter, Appl. Catal. A: Gen. 187 (1999) 207212. [7] A.A. Vargas-Tah, R.C. García, L.F.P. Archila, J.R. Solis, A.J.G. López, Catal. Today 107 (2005) 713-718.

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[8] K. S. Triantafyllidis, E. A. Deliyanni, Chem. Eng. J. 236 (2014) 406-414. [9] F. Subhan, B.S. Liu, Chem. Eng. J. 178 (2011) 69-77.

[10] F. Subhan, B.S. Liu, Y. Zhang, X.G. Li, Fuel Process. Technol. 97 (2012) 71-78.

U

[11] D. Del Rio, U. Sedran, G. de la Puente, Int. J. Chem. React. Eng. 10 (2012). [12] Y. Aponte, D. Djaouadi, H. de Lasa, Fuel 128 (2014) 71-87.

A

N

[13] A.P. Glotov, S.V. Kardashev, S.V. Egazar’yants, S.V. Lysenko, V.A. Vinokurov, E.A. Karakhanov, Chem. Tech. Fuels Oils 52 (2016) 171-174.

M

[14] A. Corma, M.S. Grande, V. Gonzalez-Alfaro, A.V. Orchilles, J. Catal. 159 (1996) 375382. [15] A. V. Karthikeyani, N. Anantharaman, K. M. Prabhu, L. Kumaresan, C.A. Pulikottil, S.S.V. Ramakumar, Int. J. Hydrogen Energy 42 (2017) 26259-26544.

ED

[16] M. B. Siddiqui, S. Ahmed, A.M. Aitani, C.F. Dean, Appl. Catal. A: Gen. 303 (2006) 116-120.

PT

[17] R. Mokaya, W. Jones, Z. Luan, M.D. Alba, J. Klinowski, Catal. Lett. 37 (1996) 113120. [18] S. Jun, R. Ryoo, J. Catal. 195 (2000) 237-243.

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[19] M.R. Awual, M.M. Hasan, T. Ihara, T. Yaita, Micropor. and Mesopor. Mat. 197 (2014) 331-338. [20] M. Ebrahimi-Gatkash, H. Younesi, A. Shahbazi, A. Heidari, Appl. Water Sci. 7 (2017) 1887-1901.

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[21] M. Jacquin, D.J. Jones, J. Rozière, S. Albertazzi, A. Vaccari, M. Lenarda, L. Storaro, R. Ganzerla, Appl. Catal. A: Gen. 251 (2003) 131-141. [22] R. Mokaya, J. Phys. Chem. B 104 (2000) 8279-8286 [23] A.P. Glotov, N.S. Levshakov, A.V. Vutolkina, S.V. Lysenko, Pet. Chem. 58 (2018) 214-219. [24] F. Can, A. Travert, V. Ruaux, J.P. Gilson, F. Maugé, R. Hu, R.F. Wormsbecher, J. Catal. 249 (2007) 79-92. [25] E.A. Karakhanov, A.P. Glotov, A.G. Nikiforova, A.V. Vutolkina, A.O. Ivanov, S.V. Kardashev, A.L. Maksimov, S.V. Lysenko, Fuel Process. Technol. 153 (2016) 50-57.

[26] A.V. Anisimov, S.V. Lysenko, M.V. Terenina, A.P. Glotov, N.S. Levshakov, A.G. Nikiforova, Theor. Found. Chem. Eng. 51 (2017) 825-829. [27] A.P. Glotov, N.S. Levshakov, M.I. Artemova, E.M. Smirnova, A.V. Vutolkina, S.V. Lysenko, Chem. Technol. Fuels Oils 54 (2018) 15-23. [28] J.T. Tompkins, R. Mokaya, ACS Appl. Mater. Interfaces 6 (2014) 1902-1908. [29] Q. Li, Z. Wu, B. Tu, S.S. Park, C.S. Ha, D. Zhao, Micropor. and Mesopor. Mat. 135 (2010) 95-104. [30] Sun, H., Tang, Q., Du, Y., Liu, X., Chen, Y., & Yang, Y., J. Colloid. Interf. Sci. 333 (2009) 317-323.

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[31] ASTM International, West Conshohocken, PA, ASTM D2887 / D2887-16, Standard Test Method for Boiling Range Distribution of Petroleum Fractions by Gas Chromatography, www.astm.org.

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[32] ASTM International, West Conshohocken, PA, ASTM D3907/D3907M-13, Standard Test Method for Testing Fluid Catalytic Cracking (FCC) Catalysts by Microactivity Test, www.astm.org. [33] T. Chiranjeevi, G.M. Kumaran, J.K. Gupta, G.M. Dhar, Thermochim. Acta. 443 (2006) 87-92.

U

[34] H. Chen, Y. Wang, Ceram. Int. 28 (2002) 541-547.

N

[35] M. Kruk, M. Jaroniec, C.H. Ko, R. Ryoo, Chem. Mater. 12 (2000) 1961-1968. [36] D. Del Rio, R. Bastos, U. Sedran, Catal. Today 213 (2013) 206-210.

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[37] M. A. B. Siddiqui, A. M. Aitani, Pet. Sci. Techn. 25 (2007) 299-313.

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Fig. 1. Low-angle XRD patterns of Al-MCM-41 (A) and Al-SBA-15 (B)

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Fig. 2. N2 adsorption–desorption isotherms of La/Al-MCM-41/Al2O3, La/Al-SBA-15/Al2O3 and La/Al-SBA-16/Al2O3.

D

IP T

C

SC R

B

ED

M

A

N

U

A

A

CC E

PT

Fig. 3. TEM micrographs of the Al-SBA-16 (A), Al-SBA-15 (B), Al-MCM-41 (C) and La/Al-MCM-41/Al2O3 (D)

IP T SC R

A

CC E

PT

ED

M

A

N

U

Fig. 4. Correlation between sulfur reduction activity and acidity of additives

IP T SC R

A

CC E

PT

ED

M

A

N

U

Fig. 5. Product yields and sulfur concentration in liquid products on e-cat blended with aluminosilicates supported La additives

IP T SC R

A

CC E

PT

ED

M

A

N

U

Fig. 6. Nitrogen adsorption/desorption isotherms for La/Al-MCM-41/Al2O3 before and after steaming

A

CC E

PT

ED

M

A

N

U

SC R

IP T

Scheme 1. Synthesis of sulfur reduction additives

Table 1 Properties of the feedstock Density at 20°C, g/cm3

1.93

0.910

Distillation, °C

Conradson carbon residue, wt% 0.16

Initial boiling point 333

10%

50%

380

437

Final boiling point 535

A

CC E

PT

ED

M

A

N

U

SC R

IP T

Sulfur content, wt%

Table 2 Properties of the e-cat Specific Packing surface density, Dpore, A area, g/cm3 m2/g 0.898 158 43 40-45, μm 7.9

Vpore, cm3/g

Rare earths

Na2O

Fe2O3

Al2O3

Coke

0.13 1.30 0.46 0.80 32.0 0.079 Particle size distribution, wt% 45-63, 63-80, 80-100, 100-160, 160-315, >315, μm μm μm μm μm μm 21.4 32.9 20.0 13.6 0.87 0.27

A

CC E

PT

ED

M

A

N

U

SC R

IP T

20-40, μm 2.0

Content, wt%

Table 3 Parameters of simulated distillation method He Gas consumption, ml/min 42 Detector temperature, °C

H2 25

Air 250

370

Vaporizer temperature, °C

370 Isotherm, min

Heating rate, °C/min

35 340

1 15

20 -

A

CC E

PT

ED

M

A

N

U

SC R

IP T

Column temperature, °C

Vpore (cm3/g) 0.59 0.37 0.53 0.42 0.49 0.43 0.46 0.43

A

CC E

PT

ED

M

A

N

U

SC R

Dpore (Ǻ) 41 40 49 46 36 37 60 55

IP T

Table 4 Textural properties of the test materials Material SBET (m2/g) Al-MCM-41/Al2O3 647 La/Al-MCM-41/Al2O3 515 Al-SBA-15/Al2O3 504 La/Al-SBA-15/Al2O3 490 Al-SBA-16/Al2O3 592 La/Al-SBA-16/Al2O3 581 Al2O3 200 La/Al2O3 169

a

Ammonia amount (μmol/g) desorbed below 300 °C Ammonia amount (μmol/g) desorbed above 300 °C

A

CC E

PT

ED

M

A

N

U

SC R

b

Total desorbed ammonia 433 522 196 347 178 269 214

IP T

Table 5 Acidic properties of the test materials determined by NH3-TPD Weak and medium Strong acid Sample acid sitesa sitesb Al-MCM-41/Al2O3 256 177 La/Al-MCM-41/Al2O3 335 187 Al-SBA-15/Al2O3 126 70 La/Al-SBA-15/Al2O3 237 110 Al-SBA-16/Al2O3 36 142 La/Al-SBA-16/Al2O3 96 173 Al2O3 146 68