scholarly journals Mutual inhibition effect of sulfur compounds in the hydrodesulfurization of thiophene, 2-ethylthiophene and benzothiophene ternary mixture

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Catalina Calin ◽  
Cristian Leostean ◽  
Ancuța Roxana Trifoi ◽  
Elena-Emilia Oprescu ◽  
Elizabeth Wiita ◽  
...  
Keyword(s):  
Ternary Mixture ◽  
Flow Reactor ◽  
Fixed Bed ◽  
Chemical Species ◽  
Sulfur Compounds ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Total Acidity ◽  
Mutual Inhibition ◽  
Inhibition Effect

AbstractThe hydrodesulphurization of a model component and equimolar ternary mixture of thiophene, 2-ethylthiophene and benzothiophene over sulphided CoMo/γ-Al2O3 and CoMo/γ-Al2O3-Nb2O5 catalysts were investigated in a fixed bed flow reactor. The catalysts were prepared by incipient wetness impregnation method and characterized by textural characteristics, total acidity and chemical species present on the catalysts surface. The characterization results showed that both CoMo/γ-Al2O3-Nb2O5 and sulphided CoMo/γ-Al2O3 catalysts exhibit a mesoporous structure with cylindrical pores open at both ends, evidenced by the IV type adsorption–desorption isotherm with a H1 hysteresis loop and have an average pore diameter between 3 and 4 nm. The chemical species present on the catalysts surface evaluated by XPS indicated that Co2+ and Mo4+ species are present in the sulfide form on both catalysts surfaces. In addition, there are also found oxidic species arising from incomplete reduction and sulphidation. The presence of niobium oxide in the catalytic support had a positive effect in leading to higher specific surface area (170 m2/g) and total acidity (0.421 meq/g) compared with CoMo/γ-Al2O3 catalyst (140 m2/g and 0.283 meq/g) respectively. The evaluation results from the hydrodesulfurization showed that CoMo/γ-Al2O3-Nb2O5 catalyst had a higher activity in hydrodesulphurization process of thiophene, 2-ethylthiophene and benzothiophene. The CoMo/γ-Al2O3-Nb2O5 catalyst eliminated sulfur from the single component feed (corresponding to 2380 ppm S) and reduced below 10 ppm, for the feed consisting in the equimolar ternary mixture of thiophene, 2-ethylthiophene and benzothiophene (2380 ppm S). The reactivity of thiophen compounds was reduced due to competitive adsorption. It was observed that benzothiophene inhibits the transformation of thiophene and 2-ethylthiophene. A mutual inhibition effect between sulfur compounds was also observed when thiophene, 2-ethylthiophene and benzothiophene were combined and tested over the CoMo/γ-Al2O3 catalyst. The inhibition effect had a lower intensity by introducing Nb2O5 in the catalyst support.

scholarly journals Tungsten Oxide-Modified SSZ-13 Zeolite as an Efficient Catalyst for Ethylene-To-Propylene Reaction

Catalysts ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 553
Author(s):  
Mansurbek Urol ugli Abdullaev ◽  
Sungjune Lee ◽  
Tae-Wan Kim ◽  
Chul-Ung Kim
Keyword(s):  
Tungsten Oxide ◽  
Fixed Bed ◽  
Acid Sites ◽  
Fixed Bed Reactor ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Efficient Catalyst ◽  
X Ray ◽  
Propylene Selectivity ◽  
Temperature Programmed

Among the zeolitic catalysts for the ethylene-to-propylene (ETP) reaction, the SSZ-13 zeolite shows the highest catalytic activity based on both its suitable pore architecture and tunable acidity. In this study, in order to improve the propylene selectivity further, the surface of the SSZ-13 zeolite was modified with various amounts of tungsten oxide ranging from 1 wt% to 15 wt% via a simple incipient wetness impregnation method. The prepared catalysts were characterized with several analysis techniques, specifically, powder X-ray diffraction (PXRD), Raman spectroscopy, temperature-programmed reduction of hydrogen (H2-TPR), temperature-programmed desorption of ammonia (NH3-TPD), inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and N2 sorption, and their catalytic activities were investigated in a fixed-bed reactor system. The tungsten oxide-modified SSZ-13 catalysts demonstrated significantly improved propylene selectivity and yield compared to the parent H-SSZ-13 catalyst. For the tungsten oxide loading, 10 wt% loading showed the highest propylene yield of 64.9 wt%, which was 6.5 wt% higher than the pristine H-SSZ-13 catalyst. This can be related to not only the milder and decreased strong acid sites but also the diffusion restriction of bulky byproducts, as supported by scanning transmission electron microscopy-energy dispersive X-ray spectroscopy (STEM-EDS) observation.

On efficiency of vanadium-oxide promoter in cobalt Fischer – Tropsch catalysts

2021 ◽  
Vol 1 (1-2) ◽  
pp. 15
Author(s):  
Elham Yaghoobpour ◽  
Yahya Zamani ◽  
Saeed Zarrinpashne ◽  
Akbar Zamaniyan
Keyword(s):  
Vanadium Oxide ◽  
Active Sites ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Bet Surface Area ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Fischer Tropsch ◽  
Co Conversion ◽  
Loading Amount

Promoters and their loading amount have crucial roles in cobalt Fischer – Tropsch catalysts. In this regard, the effects of vanadium oxide (V2O5) as a proposed promoter for Co catalyst supported on TiO2 have been investigated. Three catalysts with 0, 1, and 3 wt.% of V2O5 promoter loading are prepared by the incipient wetness impregnation method, and characterized by the BET surface area analyzer, XRD, H2-TPR, and TEM techniques. The fixed-bed reactor was employed for their evaluations. It was found that the catalyst containing 1 wt.% V2O5 has the best performance among the evaluated catalysts, demonstrating remarkable selectivity: 92 % C5+ and 5.7 % CH4, together with preserving the amount of CO conversion compared to the unpromoted catalyst. Furthermore, it is reported that the excess addition of V2O5 promoter (> 1 wt.%) in the introduced catalyst leads to the detrimental effect on the CO conversion and C5+ selectivity, mainly owing to diminished active sites by V2O5 loading.

What is the Effect of Promoter Loading on Alkalized Bimetallic Co-Mo Catalyst for Higher Alcohols Synthesis from Syngas?

2019 ◽  
Vol 19 (2) ◽  
pp. 86-94
Author(s):  
R. G. Moqadam ◽  
A. Tavasoli ◽  
M. Salimi
Keyword(s):  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Incipient Wetness Impregnation ◽  
Operating Pressure ◽  
Impregnation Method ◽  
Higher Alcohol Synthesis ◽  
Higher Alcohol ◽  
Alcohol Synthesis ◽  
Higher Alcohols Synthesis ◽  
Methanol Formation

Manganese and nickel co-modified K/Co/MoS2 catalysts supported on graphene were prepared by incipient wetness impregnation method for application in higher alcohol synthesis (HAS). All catalysts were characterized by X-ray diffraction (XRD), nitrogen adsorptiondesorption, temperature-programmed reduction (TPR) and transmission electron microscopy (TEM). The effect of promoters, as well as supports on higher alcohol synthesis production from syngas, was investigated in a fixed bed reactor. The process was performed with an molar ratio H2 : CO = 1 : 1, operating pressure and temperature of 4 MPa and 330 °C, respectively, and gas hourly space velocity (GHSV) 3.84 m3 (STP)/(kgcat.·h) as reaction conditions (STP – standard temperature and pressure). Results originated from practical works showed that the addition of Ni to the graphene-based catalyst increased HAS production and decreased methanol formation. The total alcohols space-time yield (STY) and alcohol selectivity on Ni/Mn/Co/Mo/K/graphene catalyst reached a maximum at 0.41 galc./(gcat.·h) and 63.51 %, respectively, which is higher than the same composition over alumina supported catalyst.

Effect of olefin and aromatics on thiophene adsorption desulfurization over modified NiY zeolites by metal Pd

RSC Advances ◽  
2016 ◽  
Vol 6 (78) ◽  
pp. 75006-75013 ◽  
Author(s):  
Xiaona Han ◽  
Haizheng Li ◽  
Haokai Huang ◽  
Liang Zhao ◽  
Liyuan Cao ◽  
...  
Keyword(s):  
Competitive Adsorption ◽  
Flow Reactor ◽  
Fixed Bed ◽  
Incipient Wetness Impregnation ◽  
Characterization Methods ◽  
Adsorption Desulfurization ◽  
Incipient Wetness

NiY and NiPdY adsorbents were prepared by incipient wetness impregnation and characterized by a series of characterization methods. Competitive adsorption desulfurization performance was evaluated in a fixed-bed flow reactor.

scholarly journals Study on Low-Temperature Catalytic Dehydrogenation Reaction of Tail Chlorine by Pd/Al2O3

2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
Hanhan Wang ◽  
Tingting Lu ◽  
Yuna Li ◽  
Bo Wu ◽  
Jianwei Xue ◽  
...  
Keyword(s):  
Low Temperature ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Incipient Wetness Impregnation ◽  
Catalytic Dehydrogenation ◽  
Impregnation Method ◽  
Pd Catalysts ◽  
Dehydrogenation Reaction ◽  
Loading Amount ◽  
Oxygen Reaction

The catalytic dehydrogenation reaction of tail chlorine by Pd was studied using a fixed-bed reactor at low temperature from 30 to 100°C. Different catalyst supports such as SiO2 and Al2O3 were applied to prepare Pd catalysts by the incipient-wetness impregnation method. And the catalysts were characterized by XRD, FTIR, XPS, SEM, and N2 adsorption-desorption. The catalyst Pd loading on both SiO2 and Al2O3 had a catalytic effect on the dehydrogenation reaction, but the carrier Al2O3 was more superior. The hydrogen conversion and selectivity of hydrogen-oxygen reaction increased first and then decreased with Pd loading amount and temperature by using Pd/Al2O3 as catalysts, but the influence of temperature was limited when it was higher than 60°C. The hydrogen conversion was 97.38% and selectivity of hydrogen-oxygen reaction was 79% when the reaction temperature was at 60°C with 1 wt.% Pd/Al2O3.

scholarly journals Ca-Modified Co/SBA-15 Catalysts for Hydrogen Production through Ethanol Steam Reforming

2013 ◽  
Vol 24 ◽  
pp. 1-16 ◽  
Author(s):  
Chen-Bin Wang ◽  
Siao Wun Liu ◽  
Kuan Fu Ho ◽  
Hsin Hua Huang ◽  
Chih Wei Tang ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Steam Reforming ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Coke Deposition ◽  
Incipient Wetness Impregnation ◽  
Hydrogen Yield ◽  
Impregnation Method ◽  
Steam Reforming Of Ethanol ◽  
Incipient Wetness

Hydrogen production through steam reforming of ethanol (SRE) over the Ca-modified Co/SBA-15 catalysts was studied herein to evaluate the catalytic activity, stability and the behavior of coke deposition. The Ca-modified SBA-15 supports were prepared from the Ca(NO3)2·4H2O (10 wt%) which was incorporated to SBA-15 by incipient wetness impregnation (assigned as Ca/SBA-15) and direct hydrothermal (assigned as Ca-SBA-15) method. The active cobalt species from the Co(NO3)2·6H2O (10 wt%) was loaded to SiO2, SBA-15 and modified-SBA-15 supports with incipient wetness impregnation method to obtain the cobalt catalysts (named as Co/SiO2, Co/SBA-15, Co-Ca/SBA-15 and Co/Ca-SBA-15, respectively). The prepared catalysts were characterized by using X-ray diffraction (XRD), temperature programmed reduction (TPR), transmission electron microscopy (TEM) and BET. The catalytic performance of the SRE reaction was evaluated in a fixed-bed reactor. The results indicated that the Co/Ca-SBA-15 catalyst was preferential among these catalysts and the ethanol can be converted completely at 375 °C. The hydrogen yield (YH2) approached 4.76 at 500 °C and less coke deposited. Further, the long-term stability test of this catalyst approached 100 h at 500 °C and did not deactivate.

scholarly journals Catalytic Conversion of Residual Palm Oil in Spent Bleaching Earth (SBE) By HZSM-5 Zeolite based-Catalysts

2018 ◽  
Vol 13 (3) ◽  
pp. 456 ◽  
Author(s):  
Mohd Lukman Musa ◽  
Ramli Mat ◽  
Tuan Amran Tuan Abdullah
Keyword(s):  
Palm Oil ◽  
Batch Reactor ◽  
Bleaching Earth ◽  
Fixed Bed ◽  
Nitrogen Adsorption ◽  
Catalytic Conversion ◽  
Fixed Bed Reactor ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Liquid Biofuel

Bleaching earth is used to remove colour, phospholipids, oxidized products, metals and residual gums in the palm oil process refinery. Once adsorption process end, the spent bleaching earth (SBE) which contains approximately 20-40 wt. % of the adsorbed oil was usually disposed to landfills. The oil content in SBE was recovered by catalytic cracking using transition metal (Cu, Zn, Cr, and Ni) doped HZSM-5 zeolite in a batch reactor (pyrolysis zone) and fixed bed reactor (catalyst bed). The 5 wt. % of each metallic was introduced in HZSM-5 zeolite using incipient wetness impregnation method. The main objective of this study was to investigate the performance of modified HZSM-5 zeolite for cracking of residual oil in SBE. The physicochemical properties of the catalysts were characterized    using XRD, FTIR, Nitrogen adsorption, and TPD-NH3.  Liquid biofuel obtained from cracking was analyzed by GC-MS. The incorporation of metallic loaded on HZSM-5 zeolite has reduced the surface area of the catalyst that gives a significant impact to the catalytic behavior. The Ni/HZSM-5 zeolite exhibited the highest yields of alkenes as compared to others but slightly decreases the yield of alkanes whereas in contrast with the Cr/HZSM-5, the obtained alkanes were found higher than that of alkenes. In addition, the Cr/HZSM-5 and Ni/HZSM-5 favored the conversion of polycyclic aromatics to mono-aromatics, whereas parent HZSM-5 catalyst favored the formation of poly-aromatics. These results indicated that the metal loaded on HZSM-5 can promote the cracking of heavy fractions to lighter hydrocarbon thus can be used for cracking oil in SBE. Copyright © 2018 BCREC Group. All rights reservedReceived: 10th December 2017; Revised: 31st May 2018; Accepted: 10th June 2018How to Cite: Musa, M.L., Mat, R., Abdullah, T.A.T. (2018). Catalytic Conversion of Residual Palm Oil in Spent Bleaching Earth (SBE) By HZSM-5 Zeolite based-Catalysts. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (3): 456-465 (doi:10.9767/bcrec.13.3.1929.456-465)Permalink/DOI: https://doi.org/10.9767/bcrec.13.3.1929.456-465 

scholarly journals The Effect of Temperature on Catalytic Pyrolysis of HDPE Over Ni/Ce/Al2O3

2021 ◽  
Vol 77 (1) ◽  
pp. 26-35
Author(s):  
V. Balasundram ◽  
N. Ibrahim ◽  
R. Isha
Keyword(s):  
Catalytic Pyrolysis ◽  
Fixed Bed ◽  
Hydrogen Gas ◽  
Economic Feasibility ◽  
Fixed Bed Reactor ◽  
Effect Of Temperature ◽  
High Yield ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Pyrolytic Oil

The main objective of the current work is to investigate the influence of reaction temperature on catalytic pyrolysis of High-Density Polyurethane (HDPE) over Ni/Ce/Al2O3 into enriched hydrocarbons of pyrolytic oil and gas The experiments were performed at four different pyrolysis reaction temperatures (500, 600, 700, and 800 °C) via in-situ fixed bed reactor. The Al2O3 (75 wt.%) was used as a support, while nickel (20 wt.%) and cerium (5 wt.%) were impregnated as promoters via incipient wetness impregnation method. The catalyst to plastic mass ratio was kept constant at 1:1 for all investigated samples. The results revealed that the Ni/Ce/Al2O3 catalyst has synergistic effects on the catalytic pyrolysis of HDPE into a high yield of hydrocarbon compounds (C5 – C20) in pyrolytic oil and hydrogen gas composition in pyrolytic gas. The highest yield of pyrolytic oil was achieved at 700 °C (53.23 %), while the highest yield of pyrolytic gas was achieved at 800 °C (67.85 %). The small molecular hydrocarbons in pyrolytic oil (C5 - C9) decreases with increasing temperature from 500 to 800 °C. The highest hydrogen gas yield of 77.59 %. was achieved at 700 °C. Thus, this research has economic feasibility in producing alternative valuable energy from the plastic waste stream.

Na2WO4-Mn/mullite Catalysts for Oxidative Coupling of Methane

2011 ◽  
Vol 287-290 ◽  
pp. 3015-3019 ◽  
Author(s):  
Pinsuda Viravathana ◽  
Narathorn Sukwises ◽  
Siriporn Boonpa ◽  
Siriporn Larpkiattaworn
Keyword(s):  
Oxidative Coupling ◽  
Fixed Bed ◽  
Oxidative Coupling Of Methane ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Xps Spectra ◽  
Xrd Pattern ◽  
Tube Reactor ◽  
Bet Method ◽  
Mn Species

The catalysts, 5 wt% Na2WO4-2 wt% Mn on mullites sintered at 1200°C, 1300°C, 1400°C, and 1500 °C, were prepared by incipient wetness impregnation method for the oxidative coupling of methane (OCM) reaction in a fixed-bed quartz tube reactor. These catalysts were characterized by XRD, XPS and BET method. The XRD pattern of Na2WO4-Mn/mullite indicated that the main crystal phase of metal oxide was MnWO4. From the XPS spectra, the results revealed the information on Na, W and Mn species distributed on the catalyst surface. For catalytic activity testing, Na2WO4-Mn/mullite sintered at 1300 °C showed the highest C2selectivity of 11.4% and Na2WO4-Mn/mullite sintered at 1400 °C showed the highest CH4conversion of 56.6%.

Synthesis and Characterization of Cu/ZnO Catalyst on Carbon Nanotubes and Al2O3 Supports

2018 ◽  
Vol 916 ◽  
pp. 139-143 ◽  
Author(s):  
Noor Asmawati Mohd Zabidi ◽  
Tuan Syahylah Tuan Sulong ◽  
Sardar Ali
Keyword(s):  
Carbon Nanotubes ◽  
Methyl Formate ◽  
Fixed Bed ◽  
Supported Catalyst ◽  
Hydrogenation Reaction ◽  
Fixed Bed Reactor ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Attractive Option ◽  
Multi Walled Carbon Nanotubes

CO2 conversion into valuable chemicals is an attractive option to deal with the increasing CO2 concentration in the atmosphere. In this study, Cu/ZnO catalyst was synthesized on multi-walled carbon nanotubes (MWCNTs) and Al2O3 supports via incipient wetness impregnation method. The physicochemical properties of the catalysts were investigated using TEM, XRD, N2 adsorption-desorption analysis, H2-TPR and XPS. The performance of the synthesized catalysts in a CO2 hydrogenation reaction was evaluated in a fixed-bed reactor at 503 K, 22.5 bar and H2:CO2 ratio of 3:1. TEM images showed that Cu/ZnO nanoparticles were deposited inside the CNTs as well as on the exterior walls of the CNTs. The average CuO crystallite size on Al2O3 and CNTs supports was 15.7 and 11 nm, repectively. Results of H2-TPR studies showed that the reducibility of the catalyst was improved on the CNTs support. XPS analysis confirmed the presence of Cu2+ in the samples, however, the binding energy of Cu 2p3/2 peak on the Al2O3 support was shifted to higher value compared to that of CNTs support. Products obtained from the CO2 hydrogenation reaction in the presence of these catalyts were methanol, ethanol, methyl formate and methane. The CO2 conversion of around 23% was obtained using both types of catalysts, however, Cu/ZnO on CNTs resulted in higher yield of methyl formate compared to that of Al2O3-supported catalyst.

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