scholarly journals Hydrogen Production through Autothermal Reforming of Ethanol: Enhancement of Ni Catalyst Performance via Promotion

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 5176
Author(s):  
Ekaterina Matus ◽  
Olga Sukhova ◽  
Ilyas Ismagilov ◽  
Mikhail Kerzhentsev ◽  
Olga Stonkus ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Structural Characteristics ◽  
H2 Production ◽  
Autothermal Reforming ◽  
Molar Ratio ◽  
Ni Catalyst ◽  
Hydrogen Yield ◽  
Impregnation Method ◽  
Transmission Electron ◽  
Preparation Mode

Autothermal reforming of bioethanol (ATR of C2H5OH) over promoted Ni/Ce0.8La0.2O1.9 catalysts was studied to develop carbon-neutral technologies for hydrogen production. The regulation of the functional properties of the catalysts was attained by adjusting their nanostructure and reducibility by introducing various types and content of M promoters (M = Pt, Pd, Rh, Re; molar ratio M/Ni = 0.003–0.012). The composition–characteristics–activity correlation was determined using catalyst testing in ATR of C2H5OH, thermal analysis, N2 adsorption, X-ray diffraction, transmission electron microscopy, and EDX analysis. It was shown that the type and content of the promoter, as well as the preparation mode (combined or sequential impregnation methods), determine the redox properties of catalysts and influence the textural and structural characteristics of the samples. The reducibility of catalysts improves in the following sequence of promoters: Re < Rh < Pd < Pt, with an increase in their content, and when using the co-impregnation method. It was found that in ATR of C2H5OH over bimetallic Ni-M/Ce0.8La0.2O1.9 catalysts at 600 °C, the hydrogen yield increased in the following row of promoters: Pt < Rh < Pd < Re at 100% conversion of ethanol. The introduction of M leads to the formation of a NiM alloy under reaction conditions and affects the resistance of the catalyst to oxidation, sintering, and coking. It was found that for enhancing Ni catalyst performance in H2 production through ATR of C2H5OH, the most effective promotion is with Re: at 600 °C over the optimum 10Ni-0.4Re/Ce0.8La0.2O1.9 catalyst the highest hydrogen yield 65% was observed.

scholarly journals Hydrogen Production by Partial Oxidation Reforming of Methane over Ni Catalysts Supported on High and Low Surface Area Alumina and Zirconia

Processes ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 499 ◽  
Author(s):  
Anis Fakeeha ◽  
Ahmed A. Ibrahim ◽  
Hesham Aljuraywi ◽  
Yazeed Alqahtani ◽  
Ahmad Alkhodair ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Hydrogen Production ◽  
Surface Area ◽  
Partial Oxidation ◽  
Reaction Temperature ◽  
Molar Ratio ◽  
Hydrogen Yield ◽  
Impregnation Method ◽  
H2 Yield ◽  
Partial Oxidation Reforming

The catalytic activity of the partial oxidation reforming reaction for hydrogen production over 10% Ni supported on high and low surface area alumina and zirconia was investigated. The reforming reactions, under atmospheric pressure, were performed with a feed molar ratio of CH4/O2 = 2.0. The reaction temperature was set to 450–650 °C. The catalytic activity, stability, and carbon formation were determined via TGA, TPO, Raman, and H2 yield. The catalysts were calcined at 600 and 800 °C. The catalysts were prepared via the wet-impregnation method. Various characterizations were conducted using BET, XRD, TPR, TGA, TPD, TPO, and Raman. The highest methane conversion (90%) and hydrogen yield (72%) were obtained at a 650 °C reaction temperature using Ni-Al-H-600, which also showed the highest stability for the ranges of the reaction temperatures investigated. Indeed, the time-on-stream for 7 h of the Ni-Al-H-600 catalyst displayed high activity and a stable profile when the reaction temperature was set to 650 °C.

Parametric Study of an Autothermal Micro Surface Reactor for Hydrogen Production

2010 ◽  
Author(s):  
M. H. Akbari ◽  
A. H. Sharafian Ardakani ◽  
M. Andisheh Tadbir
Keyword(s):  
Hydrogen Production ◽  
Rectangular Cross Section ◽  
Surface Reactions ◽  
Chemical Species ◽  
Space Velocity ◽  
Autothermal Reforming ◽  
Molar Ratio ◽  
Hydrogen Yield ◽  
Governing Equations ◽  
Reactor Model

Hydrogen production through autothermal reforming (ATR) of hydrocarbons, such as methane, is one option of interest for mobile applications of hydrogen fuel cells. In the present study, a numerical investigation of catalytic autothermal reforming of methane in a surface microreactor is presented. A three-dimensional ATR reactor model is developed to simulate the flow and surface reactions in a microchannel of rectangular cross section with 340-μm sides, and total length of 8.5 mm. A four-reaction mechanism is implemented to simulate the surface reactions on a Ni/Al2O3 catalyst. The governing equations in the model include conservations of mass, momentum, energy and chemical species. A CFD code based on the finite-volume method has been developed in-house to solve the governing equations. Validation of the results against available data confirms the accuracy of the numerical approach. The simulation results reveal the dependency of hydrogen yield on space velocity (SV), air/fuel molar ratio (A/F), water/fuel molar ratio (W/F), and the gas feed temperature.

Activity of Copper and Nickel Loaded on HZSM-5Zeolite Based Catalyst for Steam Reforming of Glycerol to Hydrogen

2014 ◽  
Vol 699 ◽  
pp. 504-509
Author(s):  
Hafizah Abdul Halim Yun ◽  
Ramli Mat ◽  
Tuan Amran Tuan Abdullah ◽  
Mahadhir Mohamed ◽  
Anwar Johariand Asmadi Ali
Keyword(s):  
Hydrogen Production ◽  
Steam Reforming ◽  
Fixed Bed ◽  
Operating Conditions ◽  
Zeolite Catalysts ◽  
Fixed Bed Reactor ◽  
Molar Ratio ◽  
Hydrogen Yield ◽  
Impregnation Method ◽  
Glycerol Conversion

The study focuses on hydrogen production via glycerol steam reforming over copper and nickel loaded on HZSM-5 zeolite based catalyst. The catalysts were prepared by using different loading amount of copper (0-10wt%) and nickel (0-10wt%) on HZSM-5 zeolite catalysts through wet impregnation method and was characterized by X-Ray Diffraction (XRD). The performances of catalysts were evaluated in terms of glycerol conversion and hydrogen production at 500°C using 6:1 of water to glycerol molar ratio (WGMR) in a tubular fixed bed reactor. All the catalysts had achieved more than 85% of glycerol conversion except that of 5%Cu loaded on HZSM-5 catalyst. The addition of nickel into 5% Cu/HZSM-5 catalyst had increased the hydrogen yield. Similar trend was observed when copper was added into Ni/HZSM-5 catalyst but using copper loaded on HZSM-5 alone was unable to produce hydrogen compared to using nickel catalyst alone. It showed that copper acted as a promoter for hydrogen production. It was established that a 5wt% of Cu with 10wt% of Ni loaded on HZSM-5 catalyst showed significant improvement in terms of hydrogen yield and gaseous product compositions at selected operating conditions.

Autothermal Reforming of Propane Over Ni Catalysts Supported on a Variety of Perovskites

2007 ◽  
Vol 7 (11) ◽  
pp. 4013-4016 ◽  
Author(s):  
SeungSoo Lim ◽  
DongJu Moon ◽  
JongHo Kim ◽  
YoungChul Kim ◽  
NamCook Park ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Storage Capacity ◽  
Flow Reactor ◽  
Oxygen Storage Capacity ◽  
Autothermal Reforming ◽  
Oxygen Storage ◽  
Hydrogen Yield ◽  
Impregnation Method ◽  
Ni Catalysts ◽  
Atmospheric Flow

Autothermal reforming of propane for hydrogen over Ni catalysts supported on a variety of perovskites was performed in an atmospheric flow reactor. Perovskite is known for its higher thermal stability and oxygen storage capacity, but catalytic activity of itself is low. A sites of the ABO3 structured perovskites were occupied by La while B sites by one of Fe, Co, Ni, and Al by citrate method. The composition of the reactant mixture was H2O/C/O2 = 8.96/1.0/1.1. The changes in the states of the catalysts after reaction were analyzed by XRD, TPD, and TGA. Ni/LaAlO3 catalyst maintained the perovskite structure after reaction. It showed higher hydrogen yield and thermal stability compared to those of the catalysts with Fe, Co, or Ni in B sites. Catalysts prepared by deposition-precipitation (DP) method showed higher activity than those prepared by impregnation method, presumably due to the smaller sizes of the NiO crystal particles.

Hydrogen Production via Catalytic Autothermal Reforming of Desulfurized Jet-A Fuel

2016 ◽  
Author(s):  
Shuyang Zhang ◽  
Xiaoxin Wang ◽  
Peiwen Li
Keyword(s):  
Energy Efficiency ◽  
Hydrogen Production ◽  
Hydrogen Storage ◽  
Coke Formation ◽  
Autothermal Reforming ◽  
Operating Conditions ◽  
Hydrogen Yield ◽  
Fuel Conversion ◽  
Optimal Operating ◽  
Reaction Equilibrium

On-board hydrogen production via catalytic autothermal reforming is beneficial to vehicles using fuel cells because it eliminates the challenges of hydrogen storage. As the primary fuel for both civilian and military air flight application, Jet-A fuel (after desulfurization) was reformed for making hydrogen-rich fuels in this study using an in-house-made Rh/NiO/K-La-Ce-Al-OX ATR catalyst under various operating conditions. Based on the preliminary thermodynamic analysis of reaction equilibrium, important parameters such as ratios of H2O/C and O2/C were selected, in the range of 1.1–2.5 and 0.5–1.0, respectively. The optimal operating conditions were experimentally obtained at the reactor’s temperature of 696.2 °C, which gave H2O/C = 2.5 and O2/C = 0.5, and the obtained fuel conversion percentage, hydrogen yield (can be large than 1 from definition), and energy efficiency were 88.66%, 143.84%, and 64.74%, respectively. In addition, a discussion of the concentration variation of CO and CO2 at different H2O/C, as well as the analysis of fuel conversion profile, leads to the finding of effective approaches for suppression of coke formation.

scholarly journals Characterization of Ag-promoted Ni/SiO2 Catalysts for Syngas Production via Carbon Dioxide (CO2) Dry Reforming of Glycerol

2016 ◽  
Vol 11 (2) ◽  
pp. 220 ◽  
Author(s):  
Norazimah Harun ◽  
Jolius Gimbun ◽  
Mohammad Tazli Azizan ◽  
Sumaiya Zainal Abidin
Keyword(s):  
Carbon Dioxide ◽  
Tubular Reactor ◽  
Dry Reforming ◽  
Bet Surface Area ◽  
Molar Ratio ◽  
Hydrogen Yield ◽  
Impregnation Method ◽  
Glycerol Conversion ◽  
Syngas Production

<p>The carbon dioxide (CO<sub>2</sub>) dry reforming of glycerol for syngas production is one of the promising ways to benefit the oversupply crisis of glycerol worldwide. It is an attractive process as it converts carbon dioxide, a greenhouse gas into a synthesis gas and simultaneously removed from the carbon biosphere cycle. In this study, the glycerol dry reforming was carried out using Silver (Ag) promoted Nickel (Ni) based catalysts supported on silicon oxide (SiO<sub>2</sub>) i.e. Ag-Ni/SiO<sub>2</sub>. The catalysts were prepared through wet impregnation method and characterized by using Brunauer-Emmett-Teller (BET) surface area, Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), and Thermo Gravimetric (TGA) analysis. The experiment was conducted in a tubular reactor which condition fixed at 973 K and CO<sub>2</sub>:glycerol molar ratio of 1, under atmospheric pressure. It was found that the main gaseous products are H₂, CO and CH<sub>4</sub> with H₂:CO molar ratio &lt; 1.0. From the reaction study, Ag(5)-Ni/SiO<sub>2</sub> results in highest glycerol conversion and hydrogen yield, accounted for 32.6% and 27.4%, respectively. Copyright © 2016 BCREC GROUP. All rights reserved</p><p><em>Received: 22<sup>nd</sup> January 2016; Revised: 22<sup>nd</sup> February 2016; Accepted: 23<sup>rd</sup> February 2016</em></p><strong>How to Cite</strong>: Harun, N., Gimbun, J., Azizan, M.T., Abidin S.Z. (2016). Characterization of Ag-promoted Ni/SiO<sub>2</sub> Catalysts for Syngas Production via Carbon Dioxide (CO<sub>2</sub>) Dry Reforming of Glycerol. <em>Bulletin of Chemical Reaction Engineering &amp; Catalysis</em>, 11 (2): 220-229 (doi:10.9767/bcrec.11.2.553.220-229)<p><strong>Permalink/DOI:</strong> http://dx.doi.org/10.9767/bcrec.11.2.553.220-229</p>

scholarly journals Catalytic Steam Reforming of Glycerol Over Cerium and Palladium-Based Catalysts for Hydrogen Production

2013 ◽  
Vol 10 (2) ◽  
Author(s):  
Ali Ebshish ◽  
Zahira Yaakob ◽  
Y. H. Taufiq-Yap ◽  
Ahmed Bshish ◽  
Abdulmajid Shaibani
Keyword(s):  
Electron Microscopy ◽  
Hydrogen Production ◽  
Steam Reforming ◽  
Catalytic Reactions ◽  
Fixed Bed Reactor ◽  
Hydrogen Yield ◽  
Water Mixture ◽  
Impregnation Method ◽  
Catalytic Steam Reforming ◽  
Total Average

In this work, catalytic steam reforming of glycerol for hydrogen production was performed over Ce/Al2O3 and Pd/Al2O3 catalysts prepared via the impregnation method. The catalysts were characterized by scanning electron microscopy (SEM-EDX), transmission electron microscopy (TEM), BET surface area, and X-ray diffraction (XRD). Two sets of catalytic reactions were conducted, one comparing 1% Pd/Al2O3 to 1% Ce/Al2O3 and the second comparing 1% Ce/Al2O3 loading to 10% Ce/Al2O3 loading. All catalytic reactions were performed using a fixed-bed reactor operated at 600 °C and atmospheric pressure. Aglycerol–water mixture at a molar ratio of 1:6 was fed to the reactor at 0.05 ml/min. In the first set of experiments, Pd/Al2O3 exhibited higher hydrogen productivity than Ce/Al2O3. A maximum hydrogen yield of 56% and a maximum selectivity of 78.7% were achieved over the Pd/Al2O3 catalyst. For the second set of experiments, the results show that the reaction conversion increased as the cerium loading increased from 1% to 10%. A total average hydrogen yield of 28.0% and a selectivity of 45.5% were obtained over 1% Ce/Al2O3, while the total average hydrogen yield and selectivity were 42.2% and 52.7%, respectively, for 10% Ce/Al2O3.

Hydrogen Production from Ethanol Steam Reforming over Ni-Cu/ZnO Catalyst

2011 ◽  
Vol 236-238 ◽  
pp. 1067-1072
Author(s):  
Li Ping Liu ◽  
Xiao Jian Ma ◽  
Peng Zhang ◽  
Ya Nan Liu
Keyword(s):  
Hydrogen Production ◽  
Steam Reforming ◽  
Fixed Bed ◽  
Surface Characteristics ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Molar Ratio ◽  
Ethanol Steam Reforming ◽  
Hydrogen Yield ◽  
Ethanol Steam

Hydrogen production by ethanol steam reforming over Ni-Cu/ZnO catalyst in the temperatures range of 250-550°C was studied on a fixed bed reactor. The effects of reaction temperature and water/ethanol molar ratio on hydrogen production were investigated. The structure and surface characteristics of the catalyst were measured by scanning electron microscopy (SEM), X-ray diffraction (XRD) and differential thermal analyzer (TG-DSC). The results show that the Ni-Cu/ZnO catalyst has good catalytic performance with higher hydrogen yield of 4.87molH2/molEtOH reacted. A comparison of hydrogen production from ethanol steam reforming over Ni-Cu/ZnO catalyst with over a commercial catalyst was made in this paper.

scholarly journals Effect of Preparation Mode on the Properties of Mn-Na-W/SiO2 Catalysts for Oxidative Coupling of Methane: Conventional Methods vs. POSS Nanotechnology

2016 ◽  
Vol 18 (2) ◽  
pp. 93 ◽  
Author(s):  
I.Z. Ismagilov ◽  
E.V. Matus ◽  
V.V. Kuznetsov ◽  
M.A. Kerzhentsev ◽  
S.A. Yashnik ◽  
...  
Keyword(s):  
Catalytic Performance ◽  
Oxidative Coupling Of Methane ◽  
Molar Ratio ◽  
High Dispersion ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Polyhedral Oligomeric Silsesquioxanes ◽  
Preparation Mode ◽  
Slurry Method ◽  
Conventional Methods

<p>Reflectance spectroscopic methods the electronic, redox and structural properties of Mn-Na-W/SiO<sub>2</sub> catalysts prepared by the incipient wetness impregnation method and mixture slurry method were studied in detail. Since POSS nanotechnology (POSS = polyhedral oligomeric silsesquioxanes) has attracted attention as tooling for synthesis of catalysts with novel properties and functionalities, we expanded this method for the preparation of Mn-Na-W/SiO<sub>2</sub> catalyst. The physicochemical and catalytic properties of Mn-Na-W/SiO<sub>2</sub> catalysts prepared by conventional methods and POSS nanotechnology were examined comparatively. In all studied Mn-Na-W/SiO<sub>2</sub> catalysts both individual oxides (MnO<sub>x</sub>, WO<sub>3</sub>) and bimetal oxide phases (Na<sub>2</sub>WO<sub>4</sub>, MnWO<sub>4</sub>) are found in addition to oxide particles of high dispersion. The UV-Vis Diffuse Reflectance indicates that Na<sup>+</sup> cations facilitates stabilization of octahedrally coordinated Mn<sup>3+</sup><sub>Oh</sub> cations in the isolated state, while Mn<sup>3+</sup><sub>Oh</sub> promote the disordering of W<sup>6+</sup> cations in the supported system. The Mn-Na-W/SiO<sub>2</sub> prepared using metal-POSS precursors marks out presence of unglobular SiO<sub>2</sub> particles, higher dispersion of MnO<sub>x</sub> and MnWO<sub>4</sub> particles and more easily reducible metal-oxide species. The catalysts prepared by incipient impregnation method and mixture slurry method have practically similar catalytic performance while the catalyst prepared by POSS nanotechnology method shows lower activity and selectivity. At 800‒850 °C the increase of C<sub>2</sub> hydrocarbons yield from 4 to 15% and the rise of molar ratio С<sub>2</sub>Н<sub>4</sub>/C<sub>2</sub>H<sub>6</sub> from 0.2 to 1 are observed when impregnation or mixture slurry method are used for catalyst preparation instead of POSS nanotechnology method.</p>

Simulation of Hydrogen Production by Using Concentrated Solar Energy Through Thermo-Chemical Water Splitting Process: Part II—Simulation of Zinc Hydrolysis Reaction to Generate Hydrogen

2011 ◽  
Author(s):  
Furqan Ahmad Khan ◽  
Kamran Siddiqui
Keyword(s):  
Hydrogen Production ◽  
Wall Temperature ◽  
Particle Diameter ◽  
Molar Ratio ◽  
Reactor Wall ◽  
Hydrogen Yield ◽  
Concentrated Solar Energy ◽  
Cylindrical Reactor ◽  
Chemical Cycle ◽  
Zinc Particle

This study is focused on the second step of ZnO/Zn thermo-chemical cycle, where zinc (produced in the first step of the cycle) reacts with steam to produce hydrogen and zinc oxide. The simulation of this hydrogen production step was carried out inside a cylindrical reactor using commercial CFD software, FLUENT. A parametric study was conducted based on the zinc particle diameter, reactor wall temperature, and steam/zinc molar ratio. The yield of hydrogen was found to increase with an increase in the reactor wall temperature, and with a decrease in the zinc particle diameter. However, steam/zinc molar ratio was found to have no effect on the hydrogen yield.

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