scholarly journals Effects of Al and Co Promoters on CuO/SBA-15/Kaolinite Catalyst Properties and CO2 Hydrogenation at Low Pressure

2021 ◽  
Vol 259 ◽  
pp. 04001
Author(s):  
Zane Abelniece ◽  
Valdis Kampars ◽  
Helle-Mai Piirsoo ◽  
Aile Tamm
Keyword(s):  
Fixed Bed ◽  
Mesoporous Structure ◽  
Xrd Analysis ◽  
Hydrogenation Reaction ◽  
Molar Ratio ◽  
Impregnation Method ◽  
Kaolinite Clay ◽  
Post Synthesis ◽  
Adsorption Desorption ◽  
Hydrogenation Of Co

CuO on mesoporous silica catalyst was prepared with post synthesis impregnation method, and the effects of Al and Co promoters on CuO/SBA-15/kaolinite catalyst properties and CO2 hydrogenation were studied. The mixing technology with kaolinite clay (containing Al2O3) was used to obtain the granules and to enhance the CO2 conversion to methanol as a product. The performance of all catalysts for catalytic hydrogenation of CO2 was evaluated on a fixed-bed tubular micro-activity reactor at 20 bar and 250°C with H2/CO2 molar ratio 3:1. XRD analysis, N2 adsorption-desorption analysis and SEM-EDX analysis indicated that the mesoporous structure of SBA-15 remains after loading with CuO and promoters, and after mixing with kaolinite clay. Results were compared with results obtained with commercial CuO/Al2O3 catalyst, which showed high MeOH selectivity (78%) during CO2 hydrogenation reaction.

CO2 valorization into synthetic natural gas (SNG) using a Co–Ni bimetallic Y2O3 based catalysts

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Radwa A. El-Salamony ◽  
Sara A. El-Sharaky ◽  
Seham A. Al-Temtamy ◽  
Ahmed M. Al-Sabagh ◽  
Hamada M. Killa
Keyword(s):  
Reaction Mechanism ◽  
Natural Gas ◽  
Fixed Bed ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Molar Ratio ◽  
Impregnation Method ◽  
Synthetic Natural Gas ◽  
Methanation Reaction ◽  
Co2 Valorization

Abstract Recently, because of the increasing demand for natural gas and the reduction of greenhouse gases, interests have focused on producing synthetic natural gas (SNG), which is suggested as an important future energy carrier. Hydrogenation of CO2, the so-called methanation reaction, is a suitable technique for the fixation of CO2. Nickel supported on yttrium oxide and promoted with cobalt were prepared by the wet-impregnation method respectively and characterized using SBET, XRD, FTIR, XPS, TPR, and HRTEM/EDX. CO2 hydrogenation over the Ni/Y2O3 catalyst was examined and compared with Co–Ni/Y2O3 catalysts, Co% = 10 and 15 wt/wt. The catalytic test was conducted with the use of a fixed-bed reactor under atmospheric pressure. The catalytic performance temperature was 350 °C with a supply of H2:CO2 molar ratio of 4 and a total flow rate of 200 mL/min. The CH4 yield was reached 67%, and CO2 conversion extended 48.5% with CO traces over 10Co–Ni/Y2O3 catalyst. This encourages the direct methanation reaction mechanism. However, the reaction mechanism over Ni/Y2O3 catalyst shows different behaviors rather than that over bi-metal catalysts, whereas the steam reforming of methane reaction was arisen associated with methane consumption besides increase in H2 and CO formation; at the same temperature reaction.

Dehydrogenation of Propane to Propene over Mesoporous ZrO2-Supported VCrO Catalysts

2014 ◽  
Vol 1008-1009 ◽  
pp. 290-294
Author(s):  
Bao Agula ◽  
Si Qin Dalai ◽  
Yue Chao Wu
Keyword(s):  
Pore Size Distribution ◽  
Pore Size ◽  
Size Distribution ◽  
Mesoporous Structure ◽  
Molar Ratio ◽  
Impregnation Method ◽  
Size Distributions ◽  
Tem Analysis ◽  
Surfactant Assisted ◽  
Uniform Pore Size

Mesoporous ZrO2with narrow mesopore size distributions has been prepared by the surfactant-assisted method of nanoparticle assembly. A series of VCrO/ZrO2catalysts with different V/Cr molar ratio (0.3, 0.6, 1.0, 1.3 and 1.6) were prepared by the wetness impregnation method and characterized by XRD, N2adsorption and TEM techniques. N2adsorption and TEM analysis revealed that the surfactant-assisted method prepared VCrO/ZrO2catalysts have wormhole-like mesoporous structure with uniform pore size distribution. VCrO/ZrO2catalysts have been applied for direct dehydrogenation of propane to propene. The optimistic catalyst was V/Cr-0.6 with highest yield of 41.7% the corresponding conversion of propane was 44.1% and selectivity to propene was 94.5% at 550 °C.

Influence Factors of Denitration Study on Catalyst Mn-Ce/TiO2

2013 ◽  
Vol 634-638 ◽  
pp. 526-530
Author(s):  
Chun Xiang Geng ◽  
Qian Qian Chai ◽  
Wei Yao ◽  
Chen Long Wang
Keyword(s):  
Reaction Temperature ◽  
Catalytic Reduction ◽  
Removal Rate ◽  
Load Capacity ◽  
Fixed Bed ◽  
Influence Factors ◽  
Space Velocity ◽  
Molar Ratio ◽  
Impregnation Method ◽  
Ammonia Gas

Selective Catalytic Reduction (SCR) processes have been one of the most widely used denitration methods at present and the property of low tempreture catalyst becomes a hot research. The Mn-Ce/TiO2 catalyst was prepared by incipient impregnation method. The influence of load capacity, reaction temperature, O2 content, etc. on denitration were studied by a fixed bed catalyst reactor with ammonia gas. Results showed that catalyst with load capacity 18% performed high NO removal rate of 90% at conditions of reaction temperature 160°C, low space velocity, NH3/NO molar ratio 1: 1, O2 concentration 6%.

scholarly journals ADSORPTION PROPERTIES OF TITANIA-SILICA MEMBRANES OBTAINED ON CERAMIC SUBSTRАTE

2018 ◽  
Vol 54 (3) ◽  
pp. 274-280
Author(s):  
T. F. Kouznetsova ◽  
A. I. Ivanets ◽  
J. D. Sauka
Keyword(s):  
Surface Area ◽  
Quartz Substrate ◽  
Cetylpyridinium Chloride ◽  
Nitrogen Adsorption ◽  
Mesoporous Structure ◽  
Adsorption Properties ◽  
Molar Ratio ◽  
Silica Membranes ◽  
Metal Silicate ◽  
Adsorption Desorption

Titania-silica membranes on a porous quartz substrate are prepared by its direct contact with metal silicate sol at various Ti/Si ratios in the conditions of coagel sedimentation and presence of cetylpyridinium chloride. The study of textural and adsorption properties of membranes is conducted by low-temperature nitrogen adsorption-desorption, including methods of t-plots and DFT theory. It was shown that obtained membranes have mesoporous structure with the specific surface area and pore hydraulic diameter varied in intervals of 64–217 m2 /g and 4–11 nm, respectively. Developed values of surface area remain up to molar ratio of Ti/Si = 50/50.

scholarly journals Thermodynamic Analysis of Methanol Synthesis via CO2 Hydrogenation Reaction

2021 ◽  
Author(s):  
Suresh Kanuri ◽  
Satyapaul A. Singh ◽  
Santanu P. Datta ◽  
Chanchal Chakraborty ◽  
Sounak Roy ◽  
...  
Keyword(s):  
Fixed Bed ◽  
Hydrogenation Reaction ◽  
Fixed Bed Reactor ◽  
Molar Ratio ◽  
Decomposition Reactions ◽  
Reverse Water Gas Shift ◽  
Equilibrium Conversion ◽  
Direct Hydrogenation ◽  
Thermodynamic Feasibility ◽  
Water Gas

Abstract The most inspiring opportunity to reduce greenhouse gas emissions is direct hydrogenation of CO2 into a commodity of products, which is also an appealing choice for generating renewable energy. CO2 hydrogenation can yield methanol which has a broad range of applications. In the present study, a thermodynamic feasibility analysis of the CO2 hydrogenation reaction is carried out using the Aspen Plus tool. CO2 hydrogenation to methanol, reverse-water-gas-shift (RWGS), and methanol decomposition reactions were considered in this analysis. The effect of different parameters such as temperature (ranging from 50 to 500°C), pressures (ranging from 1 bar to 50 bar), and CO2:H2 molar ratio (ranging from 1:3 to 1:20) on methanol yield has been investigated. The Aspen predicted data is compared with the fixed-bed reactor experimental data. High pressure and low-temperature conditions are found to be the favourable option for a higher value of methanol yield. The CO2 conversion and CH3OH selectivity are favourable when the H2/CO2 molar ratio is greater than 3. A substantial gap between the Aspen predicted equilibrium conversion of CO2 and the experimental value of CO2 conversion is observed in the study.

Analisis Struktur dan Spesies Permukaan Terhadap Kereaktifan Mangkin Oksida Mangan–Timah

2012 ◽  
Author(s):  
Mohd. Tahir Ahmad ◽  
Wan Azelee Wan Abu Bakar ◽  
Nor Aziah Buang
Keyword(s):  
Manganese Oxides ◽  
Fixed Bed ◽  
Xrd Analysis ◽  
Catalytic Performance ◽  
Impregnation Method ◽  
Catalyst Sample ◽  
Calcination Temperatures ◽  
Composition Ratios ◽  
The Relationship ◽  
Micro Reactor

Oksida timah (IV) dengan kehadiran bahan pendop memperlihatkan pelbagai aktiviti yang menarik untuk dikaji dengan mendalam. Dalam kajian ini oksida timah (IV) didopkan dengan Mn(II) dan Mn(IV) pada pelbagai nisbah komposisi dan suhu pengkalsinan menggunakan kaedah pengisitepuan. Bagi melihat aktiviti pemangkinan, sampel mangkin diuji menggunakan sistem reaktor mikro padatan tetap yang menghampiri keadaan sebenar ekzos kenderaan bermotor. Hasil ujian menunjukkan sampel mangkin yang didopkan dengan Mn(II) pada nisbah komposisi 40:60 berpotensi sebagai mangkin dua arah yang setanding dengan mangkin komersil, Pt/AI2O3 dan Hopcalite (CuMn2O4). Pengoksidaan lengkap 100% (T100) berlaku pada suhu yang rendah iaitu T100 = 100°C bagi gas CO dan T100 = 300°C bagi gas propana. Bagi memahami kaitan struktur dan keupayaan pemangkinan sampel mangkin, dua teknik pencirian dilakukan iaitu XPS dan XRD. Pencirian melalui teknik XPS mengenalpasti oksida mangan wujud dengan nombor pengoksidaan +2 dan +3 pada suhu pengkalsinan 400 dan 600°C. Kewujudan nombor pengoksidaan tersebut disahkan melalui teknik XRD iaitu bagi oksida mangan disumbang oleh Mn2O3 dan spinel Mn3O4. Didapati aktiviti pemangkinan yang terbaik bagi sampel mangkin ialah apabila sampel mangkin berada dalam percampuran kedua–dua nombor pengoksidaan tersebut. Daripada teknik XRD juga didapati darjah kehabluran sampel mangkin meningkat apabila suhu pengkalsinan ditingkatkan. Kata kunci: Aktiviti pemangkinan; XPS dan XRD Tin(IV) oxide when doped with other metal oxides exhibit interesting activities to be studied further. In this research, tin(IV) oxide was doped with Mn(II) and Mn(IV) at various composition ratios and calcination temperatures using an impregnation method. The catalytic performance of the prepared sample were investigated using a fixed bed micro-reactor system which resembled the actual exhaust gas condition. For catalyst sample doped with Mn(II) 40:60, the catalytic results have shown their potential as 2–way catalyst that are comparable with the commercial catalyst (Pt/AI2O3 and Hopcalite (CuMn2O4). Catalyst sample gave a 100% conversion (T100) at a low temperature of T100 = 100°C for CO and T100 of 300 for C3H8. To verify the relationship between the structures of the catalyst sample with their catalytic capabilities, characterisation analysis by XPS and XRD were performed. XPS analysis recalled the existence of manganese oxides with oxidation numbers of +2 and +3 at calcination temperatures of 400 and 600°C. This finding is supported by XRD analysis which showed that the manganese oxide was contributed by Mn2O3 and spinel Mn3O4. Therefore the best catalytic activities could be achieved with a catalyst sample prepared under a mixture of the two oxidation numbers. More over from the XRD technique, the degree of crystalinity of the catalyst sample increase as the calcination temperature increases. Key words: Catalytic activity; XPS and XRD

scholarly journals Metals on ZrO2: Catalysts for the Aldol Condensation of Methyl Ethyl Ketone (MEK) to C8 Ketones

Catalysts ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 622 ◽  
Author(s):  
Zahraa Al-Auda ◽  
Hayder Al-Atabi ◽  
Keith Hohn
Keyword(s):  
Methyl Ethyl Ketone ◽  
Main Product ◽  
Aldol Condensation ◽  
Fixed Bed ◽  
Hydrogenation Reaction ◽  
Fixed Bed Reactor ◽  
Molar Ratio ◽  
Phase Reaction ◽  
Methyl Ethyl ◽  
One Step

Methyl ethyl ketone (MEK) was converted to heavier ketones in one step, using a multi-functional catalyst having both aldol condensation (aldolization and dehydration) and hydrogenation properties. 15% Cu supported zirconia (ZrO2) was investigated in the catalytic gas phase reaction of MEK in a fixed bed reactor. The results showed that the main product was 5-methyl-3-heptanone (C8 ketone), with side products including 5-methyl-3-heptanol, 2-butanol, and other heavy products (C12 and up). The effects of various reaction parameters, like temperature and molar ratio of reactants (H2/MEK), on the overall product selectivity were studied. It was found that with increasing the temperature of the reaction, the selectivity to the C8 ketone increased, while selectivity to the 2-butanol decreased. Also, hydrogen pressure played a significant role in the selectivity of the products. It was observed that with increasing the H2/MEK molar ratio, the 2-butanol selectivity increased because of the hydrogenation reaction, while decreasing this ratio led to increasing the aldol condensation products. In addition, it was noted that both the conversion and selectivity to the main product increased using a low loading percentage of copper, 1% Cu–ZrO2. The highest selectivity of 5-methyl-3-heptanone reached ~64%, and was obtained at a temperature of around 180 °C and a molar ratio of H2/MEK equal to 2. Other metals (Ni, Pd, and Pt) that were supported on ZrO2 also produced 5-methyl-3-heptanone as the main product, with slight differences in selectivity, suggesting that a hydrogenation catalyst is important for producing the C8 ketone, but that the exact identity of the metal is less important.

The Catalytic Performance of Sol-Gel Alumina Supported Ti-Ce Catalysts for H2S Selective Oxidation to Elemental Sulfur

2018 ◽  
Vol 17 (5) ◽  
Author(s):  
H. Mehmet Tasdemir ◽  
Yavuz Yagizatli ◽  
Sena Yasyerli ◽  
Nail Yasyerli
Keyword(s):  
Reaction Time ◽  
Selective Oxidation ◽  
Elemental Sulfur ◽  
Sol Gel ◽  
Lewis Acidity ◽  
Molar Ratio ◽  
Feed Ratio ◽  
Impregnation Method ◽  
Durability Test ◽  
Adsorption Desorption

Abstract In this study, alumina supported Ti-Ce catalysts (10 % by weight and Ti/Ce molar ratio is 4:1) were prepared by using wet impregnation method and their catalytic activities were tested in H2S selective oxidation to elemental sulfur. The support alumina was synthesized by classical (SGC) and modified (SGM) sol-gel methods. The N2 adsorption-desorption, XRD, XPS, EDS and FTIR techniques were used to characterize the synthesized catalysts. The N2 adsorption-desorption isotherms showed that both catalysts have mesoporous structure. Only γ-Al2O3 crystalline phase together with amorphous structure were observed in the XRD patterns. The pyridine adsorbed FTIR analyzes showed that 10 %Ti-Ce@SGC and 10 %Ti-Ce@SGM catalysts have the same Lewis acidity. The activity tests were carried out at 250 °C and with a stoichiometric feed ratio of O2 to H2S being 0.5 for two different reaction times as 150 and 510 min. Complete conversion of H2S was obtained during 180 min. and 330 min. of reaction time over 10 %Ti-Ce@SGC and 10 %Ti-Ce@SGM, respectively. However, all catalysts showed very high sulfur selectivity. Sulfur deposition was detected over 10 %Ti-Ce@SGC catalyst both 150 and 510 min. of reaction time while it was observed after 510 min. of durability test over 10 %Ti-Ce@SGM catalyst. This can be the reason for the earlier loss of catalytic activity 10 %Ti-Ce@SGC than 10 %Ti-Ce@SGM.

scholarly journals Catalytic Performance of Phosphorus Incorporated HZSM-5 in Coupling Transformation of Methanol with 1-butene to Propylene

2021 ◽  
Vol 72 (3) ◽  
pp. 33-44
Author(s):  
Haifeng Tian ◽  
Yongyong Nan ◽  
Jinlong Lv ◽  
Fei Zha ◽  
Xiaohua Tang ◽  
...  
Keyword(s):  
Fixed Bed ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Molar Ratio ◽  
N2 Adsorption ◽  
Facile Hydrothermal Method ◽  
Phosphorus Species ◽  
Coupling Transformation ◽  
Ft Ir ◽  
Adsorption Desorption

Directly incorporated phosphorus species into the framework of HZSM-5 zeolite (H[P, Al]-ZSM-5) was successfully synthesized by the facile hydrothermal method. It was characterized by employing XRD, ICP-OES, SEM, FT-IR, N2 adsorption-desorption, NH3-TPD, XPS and TG-DTA, respectively. The effects of the phosphorus species content, temperature, WHSV, and the molar ratio of methanol/1-butene in coupling transformation of methanol with 1-butene to propylene catalyzed by H[P, Al]-ZSM-5 in a fixed bed reactor were studied systematically. Tests have suggested the acid content and specific surface area of H[P, Al]-ZSM-5 are reduced. Under the condition of reaction temperature at 550�Z, molar ratio of methanol/1-butene to 1.0, reaction pressure at 0.1 MPa and WHSV= 3.53 h-1, the P-modified HZSM-5 zeolite (with the P2O5 molar composition of 0.4 )the selectivity and yield of propylene are 35.6% and 32.5%, respectively.

scholarly journals Activity Evaluation of CoMo Nanoparticles Supported on Meso-microporous Composites in Dibenzothiophene Hydrodesulphurization

2019 ◽  
Vol 15 (1) ◽  
pp. 112-118
Author(s):  
Nastaran Parsafard ◽  
Mohammad Hasan Peyrovi ◽  
Zahra Mohammadian ◽  
Niloofar Atashi
Keyword(s):  
Activation Energy ◽  
High Surface ◽  
High Surface Area ◽  
Fixed Bed ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Impregnation Method ◽  
Wet Impregnation ◽  
Ft Ir ◽  
Adsorption Desorption

CoMo-supported mesoporous catalysts were synthesized by 50 wt% of HZSM-5 and 50 wt% of FSM-16, KIT-6, and MCM-48. These catalysts were prepared by the wet-impregnation method and pre-sulfided with CS2. The catalytic performance was evaluated for HDS reaction of dibenzothiophene over a temperature range of 250-400 °C in a micro fixed-bed reactor under atmospheric pressure. The supported CoMo bimetallic catalysts were characterized by XRD, XRF, FT-IR, N2 adsorption-desorption, and SEM. The CoMo/KIT-6/HZSM-5 indicate higher activity than other catalysts at 400 °C for dibenzothiophene hydrodesulphurization. Also, the best selectivity to cyclohexylbenzene (CHB) is related to CoMo/FSM-16/HZSM-5. The activation energy was also calculated for all prepared catalysts for the conversions of less than 10%; according to which, the activation energy for CoMo/KIT-6/HZSM-5 is less than other catalysts (~21 kJ/mol) which can be related to the appropriate pore size and high surface area of the support. Copyright © 2020 BCREC Group. All rights reserved 

Sign in / Sign up

Export Citation Format

Share Document