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John Adjaye - One of the best experts on this subject based on the ideXlab platform.
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Enhancement of sulfur and nitrogen removal from Heavy Gas Oil by using polymeric adsorbent followed by hydrotreatment
Fuel, 2018Co-Authors: Prachee Misra, Ajay Kumar Dalai, Sandeep Badoga, John AdjayeAbstract:Abstract This study is focused on the challenges associated with the utilization of Heavy Oil as refinery feedstock. Various catalytic and non-catalytic methods to achieve higher desulfurization of feed have been widely studied in the past. In this study, we are proposing a new integrated technology that combines selective adsorption of heterocyclic sulfur and nitrogen compounds followed by catalytic hydrotreatment. Glycidyl methacrylate based polymers were developed in bulk and used as an adsorbent for the removal of nitrogen and sulfur species. In the first step, the polymeric adsorbent reduced sulfur and nitrogen content of Heavy Gas Oil through charge transfer complex formation. Optimization of adsorption parameters was done using Taguchi orthogonal array to maximize the removal of catalyst inhibiting nitrogen heterocyclic compounds. Afterwards, hydrotreatment of polymer treated Heavy Gas Oil was studied in a trickle-bed reactor. Functionalized polymer treated feed was hydrotreated using NiMo/γ-Al2O3 catalyst synthesized in lab with 13 wt% molybdenum and 2.5 wt% nickel, and hydrodesulfurization (HDS), hydrodenitrogenation (HDN) and hydrodearomatization (HDA) activities were measured. Experiments were performed in the temperature range of 370–390 °C, pressure of 8.96 MPa, 1 h−1 LHSV and H2/Oil ratio = 600 (v/v). Prior removal of nitrogen and sulfur compounds using functionalized polymer subsequently favored the hydrotreating activity in the trickle bed reactor. Removal of refractory sulfur and nitrogen species before hydrotreatment has resulted in 94.3 wt% HDS and 63.3 wt% HDN as compared to 93.1 wt% HDS and 60.5 wt% HDN activities at optimum temperature of 390 °C. A total of 42.8% aromatic content was found in untreated HGO which decreased in the polymer pre-treated HGO. The highest HDA was observed for polymer pre-treated HGO feed at 390 °C, where the aromatic content decreased from 23.9% to 21%.
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Insights into individual and combined effects of phosphorus and EDTA on performance of NiMo/MesoAl2O3 catalyst for hydrotreating of Heavy Gas Oil
Fuel Processing Technology, 2017Co-Authors: Sandeep Badoga, John Adjaye, Ajay K Dalai, Yongfeng HuAbstract:Abstract The individual and combined effects of phosphorus, EDTA and support modification on hydrotreating of bitumen derived Heavy Gas Oil were studied. The EDTA/Ni molar ratio was varied from 0.5 to 2 for optimization and studying the effect of EDTA on activity of mesoporous alumina supported NiMo catalyst. The phosphorus was impregnated using two different methods: modified co-impregnation (MCI) and sequential impregnation (SI), and their effect on physico-chemical properties was studied. The catalysts were characterized using N 2 -physisorption, CO-chemisorption, pyridine-FTIR, H 2 -TPR, NH 3 -TPD, X-ray diffraction, High resolution-TEM and XANES. HRTEM and XANES techniques were predominantly used to determine the structural changes, and to visualize and measure active metal dispersion. All catalysts were tested for hydrotreating reactions in a continuous trickle-bed reactor at industrial conditions. The activities were measured in terms of hydrodesulfurization (HDS), hydrodenitrogenation (HDN) and hydrodearomatization (HDA). The studies on NiMo/γ-Al 2 O 3 were also performed for comparison purpose. The increase in HDS and HDN activities was observed for NiMo/MesoAl 2 O 3 catalyst and this is assigned to high metal dispersion due to large surface area and pore volume of synthesized mesoporous alumina. The addition of EDTA in NiMo/MesoAl 2 O 3 catalyst resulted in increasing the MoS 2 slab length and stacking degree, which resulted in decrease in dispersion, and HDN and HDS activities. However, the catalyst NiMoP/MesoAl 2 O 3 (MCI) containing only 2.5 wt.% P prepared by modified co-impregnation method showed the best HDS (97 wt.%) and HDN (77 wt.%) activity among all other studied catalysts. This increase in activity is attributed to the effect of mesoporous alumina and influence of P on reducibility, acidic strength, structural changes and desired molybdenum dispersion.
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insights into individual and combined effects of phosphorus and edta on performance of nimo mesoal2o3 catalyst for hydrotreating of Heavy Gas Oil
Fuel Processing Technology, 2017Co-Authors: Sandeep Badoga, John Adjaye, Ajay K Dalai, Yongfeng HuAbstract:Abstract The individual and combined effects of phosphorus, EDTA and support modification on hydrotreating of bitumen derived Heavy Gas Oil were studied. The EDTA/Ni molar ratio was varied from 0.5 to 2 for optimization and studying the effect of EDTA on activity of mesoporous alumina supported NiMo catalyst. The phosphorus was impregnated using two different methods: modified co-impregnation (MCI) and sequential impregnation (SI), and their effect on physico-chemical properties was studied. The catalysts were characterized using N 2 -physisorption, CO-chemisorption, pyridine-FTIR, H 2 -TPR, NH 3 -TPD, X-ray diffraction, High resolution-TEM and XANES. HRTEM and XANES techniques were predominantly used to determine the structural changes, and to visualize and measure active metal dispersion. All catalysts were tested for hydrotreating reactions in a continuous trickle-bed reactor at industrial conditions. The activities were measured in terms of hydrodesulfurization (HDS), hydrodenitrogenation (HDN) and hydrodearomatization (HDA). The studies on NiMo/γ-Al 2 O 3 were also performed for comparison purpose. The increase in HDS and HDN activities was observed for NiMo/MesoAl 2 O 3 catalyst and this is assigned to high metal dispersion due to large surface area and pore volume of synthesized mesoporous alumina. The addition of EDTA in NiMo/MesoAl 2 O 3 catalyst resulted in increasing the MoS 2 slab length and stacking degree, which resulted in decrease in dispersion, and HDN and HDS activities. However, the catalyst NiMoP/MesoAl 2 O 3 (MCI) containing only 2.5 wt.% P prepared by modified co-impregnation method showed the best HDS (97 wt.%) and HDN (77 wt.%) activity among all other studied catalysts. This increase in activity is attributed to the effect of mesoporous alumina and influence of P on reducibility, acidic strength, structural changes and desired molybdenum dispersion.
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synthesis and characterization of mesoporous aluminas with different pore sizes application in nimo supported catalyst for hydrotreating of Heavy Gas Oil
Applied Catalysis A-general, 2015Co-Authors: Sandeep Badoga, Rajesh V Sharma, Ajay K Dalai, John AdjayeAbstract:Abstract The mesoporous alumina materials having different textural properties were synthesized by modifying the procedures mentioned in literature. Pluronic P-123 was used as structure directing agent (SDA) and aluminum isopropoxide was used as precursor for aluminum. The materials were characterized using N2 adsorption–desorption isotherms (BET), X-ray diffraction, FTIR and high resolution-TEM (HRTEM). BET, XRD and HRTEM analyses had confirmed the synthesis of mesoporous aluminas with different textural characteristics. The synthesized mesoporous aluminas were utilized as a support material for NiMo catalyst for hydrotreating of Oil sands bitumen derived Heavy Gas Oil, in a fixed bed reactor at industrial conditions. The catalytic activity was measured in terms of hydrodesulfurization (HDS) and hydrodenitrogenation (HDN). The catalysts were characterized by BET, XRD, FTIR, Raman, CO-chemisorption, HRTEM, TPD and TPR. The activity study for conventional NiMo/γ-Al2O3 was also performed for comparison. Six types of mesoporous aluminas and corresponding catalysts were synthesized based on HNO3/H2O ratio varying from 0 to 2. It was observed that with increase in water content the surface area, pore volume and pore diameter of mesoporous aluminas increase. Moreover, the structure changes form ordered hexagonal to wormlike/sponge-like and fibular and then to corrugated platelets/rod like structures with increase in water content. However, the morphology of structure was changed after loading of active metals and the catalytic active follows the order NiMo/Meso-Al-0.6 > NiMo/Meso-Al-0.4 > NiMo/Meso-Al-2 ≈ NiMo/Meso-Al-0.2 > NiMo/Meso-Al-0 > NiMo/γ-Al2O3 > NiMo/Meso-Al-1.25. The highest activity shown by catalyst NiMo/Meso-Al-0.6 could be assigned to (i) its higher pore volume and surface area, (ii) highest metal dispersion, (iii) more number of weak acidic sites and (iv) lower Mo reduction temperatures.
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hydrotreating of Heavy Gas Oil on mesoporous zirconia supported nimo catalyst with edta
Fuel, 2014Co-Authors: Sandeep Badoga, Ajay Kumar Dalai, Rajesh V Sharma, John AdjayeAbstract:Abstract Large pore, high surface area mesoporous zirconia was synthesized using P123 as structure directing agent and was used as support material for hydrotreating of Heavy Gas Oil. The mesoporous zirconia supported NiMo hydrotreating catalyst was prepared with and without EDTA via incipient wetness impregnation method. The structural characteristics of catalysts were measured by X-ray diffraction (XRD), FT-IR, RAMAN, TPD (Temperature Programmed Desorption), TPR (Temperature Programmed Reduction), HRTEM, XANES and N 2 -adsorption desorption isotherms (BET). The hydrotreating activities of the catalysts were measured using Athabasca bitumen derived Heavy Gas Oil at industrial reaction conditions. Catalytic activity of NiMo/γ-Al 2 O 3 and NiMo SBA-15 catalysts was also determined for comparative studies. Low angle XRD and BET results support the formation of ordered mesoporous structure in the catalyst. Wide angle XRD, FT-IR and RAMAN analyses confirm the presence of mixture of monoclinic and tetragonal phase of zirconia in the catalyst. Surface acidity and type of acidic sites present were measured using NH 3 -TPD and Pyridine-FTIR. The extent of active metal dispersion in NiMo/Meso-Zr, Ni(NO 3 ) 2 –Mo/Meso-Zr and NiMo/Meso-Zr(EDTA) catalyst is shown by CO chemisorption and HRTEM analysis. It has been confirmed from physio-chemical characterization that addition of EDTA increases the catalytic activity by (i) increasing the active metal dispersion as indicated by HRTEM and CO chemisorption, (ii) increase in Ni sulfidation temperatures and (iii) decreasing the metal support interaction as shown by XANES analysis. XANES analysis revealed that molybdenum oxide is present predominantly in tetrahedral form in NiMo/Meso-Zr catalyst whereas its present predominantly in octahedral form in NiMo/Meso-Zr (EDTA) catalyst. The catalytic activity was investigated and corelated systematically with the textural and structural properties of the catalysts. The HDS and HDN activities follows the order: NiMo/Meso-Zr(EDTA) ⩾ NiMo/γ-Al 2 O 3 > NiMo/Meso-Zr > Ni(NO 3 ) 2 –Mo/Meso-Zr > NiMo/SBA-15.
Ajay Kumar Dalai - One of the best experts on this subject based on the ideXlab platform.
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Enhancement of sulfur and nitrogen removal from Heavy Gas Oil by using polymeric adsorbent followed by hydrotreatment
Fuel, 2018Co-Authors: Prachee Misra, Ajay Kumar Dalai, Sandeep Badoga, John AdjayeAbstract:Abstract This study is focused on the challenges associated with the utilization of Heavy Oil as refinery feedstock. Various catalytic and non-catalytic methods to achieve higher desulfurization of feed have been widely studied in the past. In this study, we are proposing a new integrated technology that combines selective adsorption of heterocyclic sulfur and nitrogen compounds followed by catalytic hydrotreatment. Glycidyl methacrylate based polymers were developed in bulk and used as an adsorbent for the removal of nitrogen and sulfur species. In the first step, the polymeric adsorbent reduced sulfur and nitrogen content of Heavy Gas Oil through charge transfer complex formation. Optimization of adsorption parameters was done using Taguchi orthogonal array to maximize the removal of catalyst inhibiting nitrogen heterocyclic compounds. Afterwards, hydrotreatment of polymer treated Heavy Gas Oil was studied in a trickle-bed reactor. Functionalized polymer treated feed was hydrotreated using NiMo/γ-Al2O3 catalyst synthesized in lab with 13 wt% molybdenum and 2.5 wt% nickel, and hydrodesulfurization (HDS), hydrodenitrogenation (HDN) and hydrodearomatization (HDA) activities were measured. Experiments were performed in the temperature range of 370–390 °C, pressure of 8.96 MPa, 1 h−1 LHSV and H2/Oil ratio = 600 (v/v). Prior removal of nitrogen and sulfur compounds using functionalized polymer subsequently favored the hydrotreating activity in the trickle bed reactor. Removal of refractory sulfur and nitrogen species before hydrotreatment has resulted in 94.3 wt% HDS and 63.3 wt% HDN as compared to 93.1 wt% HDS and 60.5 wt% HDN activities at optimum temperature of 390 °C. A total of 42.8% aromatic content was found in untreated HGO which decreased in the polymer pre-treated HGO. The highest HDA was observed for polymer pre-treated HGO feed at 390 °C, where the aromatic content decreased from 23.9% to 21%.
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hydrotreating of Heavy Gas Oil on mesoporous zirconia supported nimo catalyst with edta
Fuel, 2014Co-Authors: Sandeep Badoga, Ajay Kumar Dalai, Rajesh V Sharma, John AdjayeAbstract:Abstract Large pore, high surface area mesoporous zirconia was synthesized using P123 as structure directing agent and was used as support material for hydrotreating of Heavy Gas Oil. The mesoporous zirconia supported NiMo hydrotreating catalyst was prepared with and without EDTA via incipient wetness impregnation method. The structural characteristics of catalysts were measured by X-ray diffraction (XRD), FT-IR, RAMAN, TPD (Temperature Programmed Desorption), TPR (Temperature Programmed Reduction), HRTEM, XANES and N 2 -adsorption desorption isotherms (BET). The hydrotreating activities of the catalysts were measured using Athabasca bitumen derived Heavy Gas Oil at industrial reaction conditions. Catalytic activity of NiMo/γ-Al 2 O 3 and NiMo SBA-15 catalysts was also determined for comparative studies. Low angle XRD and BET results support the formation of ordered mesoporous structure in the catalyst. Wide angle XRD, FT-IR and RAMAN analyses confirm the presence of mixture of monoclinic and tetragonal phase of zirconia in the catalyst. Surface acidity and type of acidic sites present were measured using NH 3 -TPD and Pyridine-FTIR. The extent of active metal dispersion in NiMo/Meso-Zr, Ni(NO 3 ) 2 –Mo/Meso-Zr and NiMo/Meso-Zr(EDTA) catalyst is shown by CO chemisorption and HRTEM analysis. It has been confirmed from physio-chemical characterization that addition of EDTA increases the catalytic activity by (i) increasing the active metal dispersion as indicated by HRTEM and CO chemisorption, (ii) increase in Ni sulfidation temperatures and (iii) decreasing the metal support interaction as shown by XANES analysis. XANES analysis revealed that molybdenum oxide is present predominantly in tetrahedral form in NiMo/Meso-Zr catalyst whereas its present predominantly in octahedral form in NiMo/Meso-Zr (EDTA) catalyst. The catalytic activity was investigated and corelated systematically with the textural and structural properties of the catalysts. The HDS and HDN activities follows the order: NiMo/Meso-Zr(EDTA) ⩾ NiMo/γ-Al 2 O 3 > NiMo/Meso-Zr > Ni(NO 3 ) 2 –Mo/Meso-Zr > NiMo/SBA-15.
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synthesis of novel polymer poly glycidyl methacrylate incorporated with tetranitrofluorenone for selective removal of neutral nitrogen species from bitumen derived Heavy Gas Oil
Fuel Processing Technology, 2013Co-Authors: Danish Rizwan, Ajay Kumar Dalai, John AdjayeAbstract:Abstract Over the last two decades, numerous studies have been undertaken in identifying the inhibiting and deactivating effects of basic nitrogen compounds present in Heavy Gas Oil (HGO) on catalyst active sites; however, limited information is available on the presence and effect of neutral nitrogen species, which have shown to exhibit both inhibitory and deactivating effects comparable to those of the basic species. A novel pretreatment process employing the heterogeneously cross-linked macroporous polymer poly(glycidyl methacrylate) as the hydrophilic support coupled with organic compound tetranitrofluorenone has been synthesized in a four stage procedure for the selective removal of neutral nitrogen heterocyclic compounds from Heavy Gas Oil using charge transfer complexes. Scanning electron microscopy (SEM), low temperature N 2 adsorption–desorption (BET), CHNOS elemental analysis, Fourier transform infrared spectroscopy (FT-IR), epoxy content titration, and thermo gravimetry/differential thermal analyzer (TG/DTA) were employed for determining the optimum parameters during the synthesis of each stage. The optimized polymer has shown promising results with successful removal of up to 6.7% of the nitrogen species in a single contact using approximately 15 wt.% of the polymer with respect to HGO, while having little to no influence on the sulfur species. The reusability of the polymer has also shown consistency in the selective removal of nitrogen compounds, with continuous removal rates in the range of 6.7%.
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effect of pore diameter of ni mo al sba 15 catalysts on the hydrotreating of Heavy Gas Oil
Applied Catalysis A-general, 2011Co-Authors: Chandra K Mouli, Ajay Kumar Dalai, Kapil K Soni, John AdjayeAbstract:Abstract SBA-15 with pore diameter greater than 10 nm was synthesized by varying the synthesis parameters and adding swelling agent hexane and inorganic salt ammonium fluoride. Direct and post synthesis modification methods were employed to incorporate aluminum in the framework of SBA-15. In the direct synthesis approach, the highest pore diameter achieved was limited to 7 nm, but post synthesis method was employed successfully to achieve high pore diameter catalysts. The pore structure of the synthesized SBA-15 did not collapse until 13 nm of pore diameter as confirmed from the small angle XRD and TEM. The prepared Ni–Mo catalysts with different pore diameters were screened for hydrotreating of Heavy Gas Oil (HGO) in a trickle bed continuous reactor. The catalyst with 13 nm pore diameter gave highest conversion compared to other catalysts.
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application of different pore diameter sba 15 supports for Heavy Gas Oil hydrotreatment using few catalyst
Applied Catalysis A-general, 2011Co-Authors: Philip E Boahene, Ajay Kumar Dalai, Kapil K Soni, John AdjayeAbstract:Abstract This work focuses on utilizing mesoporous SBA-15 materials of different pore diameters as potential hydrotreating catalyst supports for Heavy Gas Oil (HGO). Hexane was used as swelling agent for the preparation of variable pore diameter SBA-15 materials. Four kinds of SBA-15 supported FeW catalysts with different pore diameters in the range of 5–20 nm were prepared and designated as Cats-A to D. The aqueous co-impregnation technique was employed for preparation of the catalysts. The supports were characterized by several techniques including X-ray powder diffraction (XRD) and N2 adsorption–desorption isotherms. The SBA-15 supported FeW catalysts were characterized by ICP-MS, BET surface area analysis, powder XRD, transmission electron microscopy (TEM), scanning electron microscopy (SEM) and CO chemisorption. Results from XRD profiles, TEM images, and N2 adsorption–desorption isotherms confirmed the presence of highly ordered two-dimensional hexagonal structure with cylindrical arrays of pores. The structural integrity of the samples was preserved even after loading of 2 wt.% Fe and 15 wt.% W. Hydrotreating experiments were conducted using bitumen derived Heavy Gas Oil under industrial conditions of temperature, pressure, LHSV, and Gas to Oil ratio of 375–400 °C, 8.8 MPa, 1 h−1, and 600 mL/mL, respectively. The SBA-15 supported catalyst with pore diameter of 10 nm (Cat-B) was the best among the supports studied for FeW catalysts, probably due to sufficient mass transfer of reactant liquids and Gases through the catalyst's pores while still maintaining a high surface area necessary for metal dispersion.
Ajay K Dalai - One of the best experts on this subject based on the ideXlab platform.
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effect of synthesis technique on the activity of conimo tri metallic catalyst for hydrotreating of Heavy Gas Oil
Catalysis Today, 2017Co-Authors: Sandeep Badoga, Arvind Ganesan, Ajay K Dalai, Shri ChandAbstract:Abstract The γ-Al2O3 supported CoNiMo tri-metallic catalysts were synthesized by four different procedures involving the variation in metal impregnation sequence. The catalysts were characterized using XRD, BET, HR-TEM, H2-TPR, Raman, and CO chemisorption techniques. All catalysts were tested for the hydrotreating of bitumen-derived Heavy Gas Oil in a continuous fixed bed reactor operating at typical industrial conditions of 9.0 MPa, 375–395 °C, 1 h−1 liquid hourly space velocity (LHSV) and Gas to Oil ratio of 600:1 ml/ml. The hydrotreating activity of tri-metallic catalysts is compared with that of bimetallic NiMo/γ-Al2O3 and CoMo/γ-Al2O3 catalysts. It was found that various synthesis procedures have a different impact on metal dispersion. The impregnation of Ni prior to Co results in higher dispersion of molybdenum as seen from XRD. The tri-metallic catalyst Co-NiMo/γ-Al2O3 (1.5Co 2.0Ni 13.0Mo/γ-Al2O3) synthesized has shown 8% and 38% higher hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) activity as compared to that shown by bimetallic catalysts. The higher activity shown by tri-metallic CoNiMo catalysts is ascribed to the double promotional effect of Co and Ni and formation of three types of active phases NiMoS, CoMoS and Ni-CoMoS.
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insights into individual and combined effects of phosphorus and edta on performance of nimo mesoal2o3 catalyst for hydrotreating of Heavy Gas Oil
Fuel Processing Technology, 2017Co-Authors: Sandeep Badoga, John Adjaye, Ajay K Dalai, Yongfeng HuAbstract:Abstract The individual and combined effects of phosphorus, EDTA and support modification on hydrotreating of bitumen derived Heavy Gas Oil were studied. The EDTA/Ni molar ratio was varied from 0.5 to 2 for optimization and studying the effect of EDTA on activity of mesoporous alumina supported NiMo catalyst. The phosphorus was impregnated using two different methods: modified co-impregnation (MCI) and sequential impregnation (SI), and their effect on physico-chemical properties was studied. The catalysts were characterized using N 2 -physisorption, CO-chemisorption, pyridine-FTIR, H 2 -TPR, NH 3 -TPD, X-ray diffraction, High resolution-TEM and XANES. HRTEM and XANES techniques were predominantly used to determine the structural changes, and to visualize and measure active metal dispersion. All catalysts were tested for hydrotreating reactions in a continuous trickle-bed reactor at industrial conditions. The activities were measured in terms of hydrodesulfurization (HDS), hydrodenitrogenation (HDN) and hydrodearomatization (HDA). The studies on NiMo/γ-Al 2 O 3 were also performed for comparison purpose. The increase in HDS and HDN activities was observed for NiMo/MesoAl 2 O 3 catalyst and this is assigned to high metal dispersion due to large surface area and pore volume of synthesized mesoporous alumina. The addition of EDTA in NiMo/MesoAl 2 O 3 catalyst resulted in increasing the MoS 2 slab length and stacking degree, which resulted in decrease in dispersion, and HDN and HDS activities. However, the catalyst NiMoP/MesoAl 2 O 3 (MCI) containing only 2.5 wt.% P prepared by modified co-impregnation method showed the best HDS (97 wt.%) and HDN (77 wt.%) activity among all other studied catalysts. This increase in activity is attributed to the effect of mesoporous alumina and influence of P on reducibility, acidic strength, structural changes and desired molybdenum dispersion.
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Insights into individual and combined effects of phosphorus and EDTA on performance of NiMo/MesoAl2O3 catalyst for hydrotreating of Heavy Gas Oil
Fuel Processing Technology, 2017Co-Authors: Sandeep Badoga, John Adjaye, Ajay K Dalai, Yongfeng HuAbstract:Abstract The individual and combined effects of phosphorus, EDTA and support modification on hydrotreating of bitumen derived Heavy Gas Oil were studied. The EDTA/Ni molar ratio was varied from 0.5 to 2 for optimization and studying the effect of EDTA on activity of mesoporous alumina supported NiMo catalyst. The phosphorus was impregnated using two different methods: modified co-impregnation (MCI) and sequential impregnation (SI), and their effect on physico-chemical properties was studied. The catalysts were characterized using N 2 -physisorption, CO-chemisorption, pyridine-FTIR, H 2 -TPR, NH 3 -TPD, X-ray diffraction, High resolution-TEM and XANES. HRTEM and XANES techniques were predominantly used to determine the structural changes, and to visualize and measure active metal dispersion. All catalysts were tested for hydrotreating reactions in a continuous trickle-bed reactor at industrial conditions. The activities were measured in terms of hydrodesulfurization (HDS), hydrodenitrogenation (HDN) and hydrodearomatization (HDA). The studies on NiMo/γ-Al 2 O 3 were also performed for comparison purpose. The increase in HDS and HDN activities was observed for NiMo/MesoAl 2 O 3 catalyst and this is assigned to high metal dispersion due to large surface area and pore volume of synthesized mesoporous alumina. The addition of EDTA in NiMo/MesoAl 2 O 3 catalyst resulted in increasing the MoS 2 slab length and stacking degree, which resulted in decrease in dispersion, and HDN and HDS activities. However, the catalyst NiMoP/MesoAl 2 O 3 (MCI) containing only 2.5 wt.% P prepared by modified co-impregnation method showed the best HDS (97 wt.%) and HDN (77 wt.%) activity among all other studied catalysts. This increase in activity is attributed to the effect of mesoporous alumina and influence of P on reducibility, acidic strength, structural changes and desired molybdenum dispersion.
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synthesis and characterization of mesoporous aluminas with different pore sizes application in nimo supported catalyst for hydrotreating of Heavy Gas Oil
Applied Catalysis A-general, 2015Co-Authors: Sandeep Badoga, Rajesh V Sharma, Ajay K Dalai, John AdjayeAbstract:Abstract The mesoporous alumina materials having different textural properties were synthesized by modifying the procedures mentioned in literature. Pluronic P-123 was used as structure directing agent (SDA) and aluminum isopropoxide was used as precursor for aluminum. The materials were characterized using N2 adsorption–desorption isotherms (BET), X-ray diffraction, FTIR and high resolution-TEM (HRTEM). BET, XRD and HRTEM analyses had confirmed the synthesis of mesoporous aluminas with different textural characteristics. The synthesized mesoporous aluminas were utilized as a support material for NiMo catalyst for hydrotreating of Oil sands bitumen derived Heavy Gas Oil, in a fixed bed reactor at industrial conditions. The catalytic activity was measured in terms of hydrodesulfurization (HDS) and hydrodenitrogenation (HDN). The catalysts were characterized by BET, XRD, FTIR, Raman, CO-chemisorption, HRTEM, TPD and TPR. The activity study for conventional NiMo/γ-Al2O3 was also performed for comparison. Six types of mesoporous aluminas and corresponding catalysts were synthesized based on HNO3/H2O ratio varying from 0 to 2. It was observed that with increase in water content the surface area, pore volume and pore diameter of mesoporous aluminas increase. Moreover, the structure changes form ordered hexagonal to wormlike/sponge-like and fibular and then to corrugated platelets/rod like structures with increase in water content. However, the morphology of structure was changed after loading of active metals and the catalytic active follows the order NiMo/Meso-Al-0.6 > NiMo/Meso-Al-0.4 > NiMo/Meso-Al-2 ≈ NiMo/Meso-Al-0.2 > NiMo/Meso-Al-0 > NiMo/γ-Al2O3 > NiMo/Meso-Al-1.25. The highest activity shown by catalyst NiMo/Meso-Al-0.6 could be assigned to (i) its higher pore volume and surface area, (ii) highest metal dispersion, (iii) more number of weak acidic sites and (iv) lower Mo reduction temperatures.
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hydrotreating of Heavy Gas Oil on mesoporous mixed metal oxides m al2o3 m tio2 zro2 sno2 supported nimo catalysts influence of surface acidity
Industrial & Engineering Chemistry Research, 2014Co-Authors: Sandeep Badoga, Rajesh V Sharma, Ajay K Dalai, John AdjayeAbstract:Mesoporous mixed metal oxides, TiO2–Al2O3, ZrO2–Al2O3, and SnO2–Al2O3, were synthesized using a novel method and were used as a support material for the NiMo hydrotreating catalyst. The catalyst was prepared via the incipient wetness sequential impregnation method. All catalysts were characterized using N2 adsorption–desorption isotherms (BET), X-ray diffraction, FTIR, pyridine-FTIR, acridine-FTIR, CO-chemisorption, ICP-MS, TPD, and TPR. The HDS and HDN activities of the catalysts were determined using Athabasca bitumen derived Heavy Gas Oil at industrial reaction conditions. The catalytic activity of synthesized NiMo/γ-Al2O3 catalyst was also determined for comparative studies. Low angle XRD and BET analysis has confirmed that the method developed for synthesis is suitable for the preparation of a mesoporous mixed oxide based NiMo hydrotreating catalyst. H2-TPR analysis has confirmed that the introduction of metal oxides such as ZrO2, TiO2, and SnO2 in alumina increases the active metal (Mo) and support ...
Sandeep Badoga - One of the best experts on this subject based on the ideXlab platform.
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Enhancement of sulfur and nitrogen removal from Heavy Gas Oil by using polymeric adsorbent followed by hydrotreatment
Fuel, 2018Co-Authors: Prachee Misra, Ajay Kumar Dalai, Sandeep Badoga, John AdjayeAbstract:Abstract This study is focused on the challenges associated with the utilization of Heavy Oil as refinery feedstock. Various catalytic and non-catalytic methods to achieve higher desulfurization of feed have been widely studied in the past. In this study, we are proposing a new integrated technology that combines selective adsorption of heterocyclic sulfur and nitrogen compounds followed by catalytic hydrotreatment. Glycidyl methacrylate based polymers were developed in bulk and used as an adsorbent for the removal of nitrogen and sulfur species. In the first step, the polymeric adsorbent reduced sulfur and nitrogen content of Heavy Gas Oil through charge transfer complex formation. Optimization of adsorption parameters was done using Taguchi orthogonal array to maximize the removal of catalyst inhibiting nitrogen heterocyclic compounds. Afterwards, hydrotreatment of polymer treated Heavy Gas Oil was studied in a trickle-bed reactor. Functionalized polymer treated feed was hydrotreated using NiMo/γ-Al2O3 catalyst synthesized in lab with 13 wt% molybdenum and 2.5 wt% nickel, and hydrodesulfurization (HDS), hydrodenitrogenation (HDN) and hydrodearomatization (HDA) activities were measured. Experiments were performed in the temperature range of 370–390 °C, pressure of 8.96 MPa, 1 h−1 LHSV and H2/Oil ratio = 600 (v/v). Prior removal of nitrogen and sulfur compounds using functionalized polymer subsequently favored the hydrotreating activity in the trickle bed reactor. Removal of refractory sulfur and nitrogen species before hydrotreatment has resulted in 94.3 wt% HDS and 63.3 wt% HDN as compared to 93.1 wt% HDS and 60.5 wt% HDN activities at optimum temperature of 390 °C. A total of 42.8% aromatic content was found in untreated HGO which decreased in the polymer pre-treated HGO. The highest HDA was observed for polymer pre-treated HGO feed at 390 °C, where the aromatic content decreased from 23.9% to 21%.
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effect of synthesis technique on the activity of conimo tri metallic catalyst for hydrotreating of Heavy Gas Oil
Catalysis Today, 2017Co-Authors: Sandeep Badoga, Arvind Ganesan, Ajay K Dalai, Shri ChandAbstract:Abstract The γ-Al2O3 supported CoNiMo tri-metallic catalysts were synthesized by four different procedures involving the variation in metal impregnation sequence. The catalysts were characterized using XRD, BET, HR-TEM, H2-TPR, Raman, and CO chemisorption techniques. All catalysts were tested for the hydrotreating of bitumen-derived Heavy Gas Oil in a continuous fixed bed reactor operating at typical industrial conditions of 9.0 MPa, 375–395 °C, 1 h−1 liquid hourly space velocity (LHSV) and Gas to Oil ratio of 600:1 ml/ml. The hydrotreating activity of tri-metallic catalysts is compared with that of bimetallic NiMo/γ-Al2O3 and CoMo/γ-Al2O3 catalysts. It was found that various synthesis procedures have a different impact on metal dispersion. The impregnation of Ni prior to Co results in higher dispersion of molybdenum as seen from XRD. The tri-metallic catalyst Co-NiMo/γ-Al2O3 (1.5Co 2.0Ni 13.0Mo/γ-Al2O3) synthesized has shown 8% and 38% higher hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) activity as compared to that shown by bimetallic catalysts. The higher activity shown by tri-metallic CoNiMo catalysts is ascribed to the double promotional effect of Co and Ni and formation of three types of active phases NiMoS, CoMoS and Ni-CoMoS.
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insights into individual and combined effects of phosphorus and edta on performance of nimo mesoal2o3 catalyst for hydrotreating of Heavy Gas Oil
Fuel Processing Technology, 2017Co-Authors: Sandeep Badoga, John Adjaye, Ajay K Dalai, Yongfeng HuAbstract:Abstract The individual and combined effects of phosphorus, EDTA and support modification on hydrotreating of bitumen derived Heavy Gas Oil were studied. The EDTA/Ni molar ratio was varied from 0.5 to 2 for optimization and studying the effect of EDTA on activity of mesoporous alumina supported NiMo catalyst. The phosphorus was impregnated using two different methods: modified co-impregnation (MCI) and sequential impregnation (SI), and their effect on physico-chemical properties was studied. The catalysts were characterized using N 2 -physisorption, CO-chemisorption, pyridine-FTIR, H 2 -TPR, NH 3 -TPD, X-ray diffraction, High resolution-TEM and XANES. HRTEM and XANES techniques were predominantly used to determine the structural changes, and to visualize and measure active metal dispersion. All catalysts were tested for hydrotreating reactions in a continuous trickle-bed reactor at industrial conditions. The activities were measured in terms of hydrodesulfurization (HDS), hydrodenitrogenation (HDN) and hydrodearomatization (HDA). The studies on NiMo/γ-Al 2 O 3 were also performed for comparison purpose. The increase in HDS and HDN activities was observed for NiMo/MesoAl 2 O 3 catalyst and this is assigned to high metal dispersion due to large surface area and pore volume of synthesized mesoporous alumina. The addition of EDTA in NiMo/MesoAl 2 O 3 catalyst resulted in increasing the MoS 2 slab length and stacking degree, which resulted in decrease in dispersion, and HDN and HDS activities. However, the catalyst NiMoP/MesoAl 2 O 3 (MCI) containing only 2.5 wt.% P prepared by modified co-impregnation method showed the best HDS (97 wt.%) and HDN (77 wt.%) activity among all other studied catalysts. This increase in activity is attributed to the effect of mesoporous alumina and influence of P on reducibility, acidic strength, structural changes and desired molybdenum dispersion.
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Insights into individual and combined effects of phosphorus and EDTA on performance of NiMo/MesoAl2O3 catalyst for hydrotreating of Heavy Gas Oil
Fuel Processing Technology, 2017Co-Authors: Sandeep Badoga, John Adjaye, Ajay K Dalai, Yongfeng HuAbstract:Abstract The individual and combined effects of phosphorus, EDTA and support modification on hydrotreating of bitumen derived Heavy Gas Oil were studied. The EDTA/Ni molar ratio was varied from 0.5 to 2 for optimization and studying the effect of EDTA on activity of mesoporous alumina supported NiMo catalyst. The phosphorus was impregnated using two different methods: modified co-impregnation (MCI) and sequential impregnation (SI), and their effect on physico-chemical properties was studied. The catalysts were characterized using N 2 -physisorption, CO-chemisorption, pyridine-FTIR, H 2 -TPR, NH 3 -TPD, X-ray diffraction, High resolution-TEM and XANES. HRTEM and XANES techniques were predominantly used to determine the structural changes, and to visualize and measure active metal dispersion. All catalysts were tested for hydrotreating reactions in a continuous trickle-bed reactor at industrial conditions. The activities were measured in terms of hydrodesulfurization (HDS), hydrodenitrogenation (HDN) and hydrodearomatization (HDA). The studies on NiMo/γ-Al 2 O 3 were also performed for comparison purpose. The increase in HDS and HDN activities was observed for NiMo/MesoAl 2 O 3 catalyst and this is assigned to high metal dispersion due to large surface area and pore volume of synthesized mesoporous alumina. The addition of EDTA in NiMo/MesoAl 2 O 3 catalyst resulted in increasing the MoS 2 slab length and stacking degree, which resulted in decrease in dispersion, and HDN and HDS activities. However, the catalyst NiMoP/MesoAl 2 O 3 (MCI) containing only 2.5 wt.% P prepared by modified co-impregnation method showed the best HDS (97 wt.%) and HDN (77 wt.%) activity among all other studied catalysts. This increase in activity is attributed to the effect of mesoporous alumina and influence of P on reducibility, acidic strength, structural changes and desired molybdenum dispersion.
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synthesis and characterization of mesoporous aluminas with different pore sizes application in nimo supported catalyst for hydrotreating of Heavy Gas Oil
Applied Catalysis A-general, 2015Co-Authors: Sandeep Badoga, Rajesh V Sharma, Ajay K Dalai, John AdjayeAbstract:Abstract The mesoporous alumina materials having different textural properties were synthesized by modifying the procedures mentioned in literature. Pluronic P-123 was used as structure directing agent (SDA) and aluminum isopropoxide was used as precursor for aluminum. The materials were characterized using N2 adsorption–desorption isotherms (BET), X-ray diffraction, FTIR and high resolution-TEM (HRTEM). BET, XRD and HRTEM analyses had confirmed the synthesis of mesoporous aluminas with different textural characteristics. The synthesized mesoporous aluminas were utilized as a support material for NiMo catalyst for hydrotreating of Oil sands bitumen derived Heavy Gas Oil, in a fixed bed reactor at industrial conditions. The catalytic activity was measured in terms of hydrodesulfurization (HDS) and hydrodenitrogenation (HDN). The catalysts were characterized by BET, XRD, FTIR, Raman, CO-chemisorption, HRTEM, TPD and TPR. The activity study for conventional NiMo/γ-Al2O3 was also performed for comparison. Six types of mesoporous aluminas and corresponding catalysts were synthesized based on HNO3/H2O ratio varying from 0 to 2. It was observed that with increase in water content the surface area, pore volume and pore diameter of mesoporous aluminas increase. Moreover, the structure changes form ordered hexagonal to wormlike/sponge-like and fibular and then to corrugated platelets/rod like structures with increase in water content. However, the morphology of structure was changed after loading of active metals and the catalytic active follows the order NiMo/Meso-Al-0.6 > NiMo/Meso-Al-0.4 > NiMo/Meso-Al-2 ≈ NiMo/Meso-Al-0.2 > NiMo/Meso-Al-0 > NiMo/γ-Al2O3 > NiMo/Meso-Al-1.25. The highest activity shown by catalyst NiMo/Meso-Al-0.6 could be assigned to (i) its higher pore volume and surface area, (ii) highest metal dispersion, (iii) more number of weak acidic sites and (iv) lower Mo reduction temperatures.
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Simulation of a Two-Stage Micro Trickle-Bed Hydrotreating Reactor using Athabasca Bitumen-Derived Heavy Gas Oil over Commercial NiMo/Al2O3 Catalyst: Effect of H2S on Hydrodesulfurization and Hydrodenitrogenation
International Journal of Chemical Reactor Engineering, 2006Co-Authors: Christian Botchwey, Ajay K Dalai, John AdjayeAbstract:A two-stage, micro trickle-bed reactor (for studies of the effects of hydrogen sulfide on hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) of Athabasca bitumen-derived Heavy Gas Oil over commercial NiMo/Al2O3 catalyst) has been simulated. One dimensional homogeneous mass transfer and a two dimensional heat transfer models were developed. The essence of the simulation was to enhance the understanding of the effects of hydrogen sulfide in the hydrotreating catalyst bed in a two-stage mode and also to predict the catalyst requirements for deep HDS and HDN processes. The kinetic model used in the simulation was based on the Langmuir-Hingshelwood method of rate determination. Adsorption constants were estimated by non-linear least squares method. The kinetic models were tested on independent set of data and found to predict the experimental data satisfactorily. The mass transfer simulation considered the effects of variables such as temperature and catalyst loading or liquid hourly space velocity (LHSV) on the trends of hydrogen sulfide generation and, sulfur and nitrogen conversions along the catalyst bed. The model was numerically solved using a fourth-order Runge-Kutta technique. The 1:3 wt/wt catalyst loading with inter-stage hydrogen sulfide removal was found to give the best HDN and HDS activities. Simulated results showed that doubling the present catalyst mass and operating at 653 °C with inter-stage hydrogen sulfide removal would give 6 and 179 ppm product sulfur and nitrogen, respectively. On the other hand, without hydrogen sulfide removal, only 49 and 302 ppm product sulfur and nitrogen could be attained, respectively. The heat transfer simulation compared temperature profiles in the two-stage process to a single stage process for the 1:3 wt/wt catalyst loading at 653 K. The temperature regime in Stage II was found to be more uniform unlike Stage I and the single stage. Crank Nicholson algorithm was used to solve the 2-D partial differential equations.
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Simulation of a Two-Stage Micro Trickle-Bed Hydrotreating Reactor using Athabasca Bitumen-Derived Heavy Gas Oil over Commercial NiMo/Al2O3 Catalyst: Effect of H2S on Hydrodesulfurization and Hydrodenitrogenation
International Journal of Chemical Reactor Engineering, 2006Co-Authors: Christian Botchwey, Ajay Kumar Dalai, John AdjayeAbstract:A two-stage, micro trickle-bed reactor (for studies of the effects\nof hydrogen sulfide on hydrodesulfurization (HDS) and hydrodenitrogenation\n(HDN) of Athabasca bitumen-derived Heavy Gas Oil over commercial\nNiMo/Al2O3 catalyst) has been simulated. One dimensional homogeneous\nmass transfer and a two dimensional heat transfer models were developed.\nThe essence of the simulation was to enhance the understanding of\nthe effects of hydrogen sulfide in the hydrotreating catalyst bed\nin a two-stage mode and also to predict the catalyst requirements\nfor deep HDS and HDN processes. The kinetic model used in the simulation\nwas based on the Langmuir-Hingshelwood method of rate determination.\nAdsorption constants were estimated by non-linear least squares method.\nThe kinetic models were tested on independent set of data and found\nto predict the experimental data satisfactorily. The mass transfer\nsimulation considered the effects of variables such as temperature\nand catalyst loading or liquid hourly space velocity (LHSV) on the\ntrends of hydrogen sulfide generation and, sulfur and nitrogen conversions\nalong the catalyst bed. The model was numerically solved using a\nfourth-order Runge-Kutta technique. The 1:3 wt/wt catalyst loading\nwith inter-stage hydrogen sulfide removal was found to give the best\nHDN and HDS activities. Simulated results showed that doubling the\npresent catalyst mass and operating at 653 degrees C with inter-stage\nhydrogen sulfide removal would give 6 and 179 ppm product sulfur\nand nitrogen, respectively. On the other hand, without hydrogen sulfide\nremoval, only 49 and 302 ppm product sulfur and nitrogen could be\nattained, respectively. The heat transfer simulation compared temperature\nprofiles in the two-stage process to a single stage process for the\n1:3 wt/wt catalyst loading at 653 K. The temperature regime in Stage\nII was found to be more uniform unlike Stage I and the single stage.\nCrank Nicholson algorithm was used to solve the 2-D partial differential\nequations.
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Two-Stage Hydrotreating of Athabasca Heavy Gas Oil with Interstage Hydrogen Sulfide Removal: Effect of Process Conditions and Kinetic Analyses
Industrial & Engineering Chemistry Research, 2004Co-Authors: Christian Botchwey, Ajay Kumar Dalai, John AdjayeAbstract:Two-stage hydrodenitrogenation (HDN)−hydrodesulfurization (HDS) of Heavy Gas Oil, derived from Athabasca bitumen, has been carried out in a trickle-bed microreactor using a commercial NiMo/Al2O3 catalyst. The operating conditions for the experiments were varied as follows: temperature range of 340−420 °C, reactor pressure of 950−1600 psig, liquid hourly space velocity range of 0.5−2.0 h-1, and hydrogen to Heavy Gas Oil ratio of 600 mL/mL. Variation in the catalyst loading between stages I and II was also studied. Stage I products were stripped off any generated hydrogen sulfide and further hydrotreated in stage II to see the impact of hydrogen sulfide interstage removal on the hydrotreating activities. A comparison of the two-stage results to those of the single-stage results shows an enhancement in the hydrotreating activities. For instance, a 12.6 wt % increase in the conversion of nonbasic nitrogen was observed. The optimum conditions for higher gain in HDN and HDS due to hydrogen sulfide removal were...
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Two-stage hydrotreating of Athabasca Heavy Gas Oil with interstage hydrogen sulfide removal: Effect of process conditions and kinetic analyses
Industrial and Engineering Chemistry Research, 2004Co-Authors: Christian Botchwey, Ajay Kumar Dalai, John AdjayeAbstract:Two-stage hydrodenitrogenation (HDN)-hydrodesulfurization (HDS) of Heavy Gas Oil, derived from Athabasca bitumen, has been carried out in a trickle-bed microreactor using a commercial NiMo/Al2O3 catalyst. The operating conditions for the experiments were varied as follows: temperature range of 340-420 °C, reactor pressure of 950-1600 psig, liquid hourly space velocity range of 0.5-2.0 h-1, and hydrogen to Heavy Gas Oil ratio of 600 mL/mL. Variation in the catalyst loading between stages I and II was also studied. Stage I products were stripped off any generated hydrogen sulfide and further hydrotreated in stage II to see the impact of hydrogen sulfide interstage removal on the hydrotreating activities. A comparison of the two-stage results to those of the single-stage results shows an enhancement in the hydrotreating activities. For instance, a 12.6 wt%increase in the conversion of nonbasic nitrogen was observed. The optimum conditions for higher gain in HDN and HDS due to hydrogen sulfide removal were found to be 380 °C, 7.6 MPa, and 1:3 (w/w) catalyst loading. A Langmuir-Hinshelwood model developed for the hydrogen sulfide inhibition predicts sufficiently the observed data of the two-stage process.