Ni Catalyst Properties for Ammonia Reforming: Comparison of Ni Content and Space Velocity

CO2 methanation is recognized as one of the best technologies for storing intermittent renewable energy in the form of CH4. In this study, CO2 methanation performance is investigated using Ni/Al2O3, Ru/Al2O3, and Ru-Ni/Al2O3 as the catalysts under conditions of atmospheric pressure, a molar ratio of H2/CO2 = 5, and a space velocity of 5835 h−1. For reaction temperatures ranging from 250 to 550 °C, it was found that the optimum reaction temperature is 400 °C for all catalysts studied. At this temperature, the maximum values of CO2 conversion, H2 efficiency, and CH4 yield and lowest CO yield can be obtained. With temperatures higher than 400 °C, reverse CO2 methanation results in CO2 conversion and CH4 yield decreases with increased temperature, while CO is formed due to reverse water-gas shift reaction. The experimental results showed that CO2 methanation performance at low temperatures can be enhanced greatly using the bimetallic Ru-Ni catalyst compared with the monometallic Ru or Ni catalyst. Under ascending-descending temperature changes between 250 °C and 550 °C, good thermal stability is obtained from Ru-Ni/Al2O3 catalyst. About a 3% decrease in CO2 conversion is found after three continuous cycles (74 h) test.

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The ‘Green’ Ni-UGSO Catalyst for Hydrogen Production under Various Reforming Regimes

Catalysts ◽

10.3390/catal11070771 ◽

2021 ◽

Vol 11 (7) ◽

pp. 771

Author(s):

Mostafa Chamoumi ◽

Nicolas Abatzoglou

Keyword(s):

Space Velocity ◽

Sulfur Poisoning ◽

Dry Reforming Of Methane ◽

Molar Ratio ◽

Ni Catalyst ◽

X Ray ◽

Steam Methane ◽

Catalytically Active ◽

Slag Production ◽

Temperature Levels

A new spinelized Ni catalyst (Ni-UGSO) using Ni(NO3)2·6H2O as the Ni precursor was prepared according to a less material intensive protocol. The support of this catalyst is a negative-value mining residue, UpGraded Slag Oxide (UGSO), produced from a TiO2 slag production unit. Applied to dry reforming of methane (DRM) at atmospheric pressure, T = 810 °C, space velocity of 3400 mL/(h·g) and molar CO2/CH4 = 1.2, Ni-UGSO gives a stable over 168 h time-on-stream methane conversion of 92%. In this DRM reaction optimization study: (1) the best performance is obtained with the 10–13 wt% Ni load; (2) the Ni-UGSO catalysts obtained from two different batches of UGSO demonstrated equivalent performances despite their slight differences in composition; (3) the sulfur-poisoning resistance study shows that at up to 5.5 ppm no Ni-UGSO deactivation is observed. In steam reforming of methane (SRM), Ni-UGSO was tested at 900 °C and a molar ratio of H2O/CH4 = 1.7. In this experimental range, CH4 conversion rapidly reached 98% and remained stable over 168 h time-on-stream (TOS). The same stability is observed for H2 and CO yields, at around 92% and 91%, respectively, while H2/CO was close to 3. In mixed (dry and steam) methane reforming using a ratio of H2O/CH4 = 0.15 and CO2/CH4 = 0.97 for 74 h and three reaction temperature levels (828 °C, 847 °C and 896 °C), CH4 conversion remains stable; 80% at 828 °C (26 h), 85% at 847 °C (24 h) and 95% at 896 °C (24 h). All gaseous streams have been analyzed by gas chromatography. Both fresh and used catalysts are analyzed by scanning electron microscopy-electron dispersive X-ray spectroscopy (SEM-EDXS), X-ray diffraction (XRD), and thermogravimetric analysis (TGA) coupled with mass spectroscopy (MS) and BET Specific surface. In the reducing environment of reforming, such catalytic activity is mainly attributed to (a) alloys such as FeNi, FeNi3 and Fe3Ni2 (reduction of NiFe2O4, FeNiAlO4) and (b) to the solid solution NiO-MgO. The latter is characterized by a molecular distribution of the catalytically active Ni phase while offering an environment that prevents C deposition due to its alkalinity.

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Novel Ni-Co-Mo-K Catalysts Supported on Multiwalled Carbon Nanotubes for Higher Alcohols Synthesis

Journal of Catalysts ◽

10.1155/2013/942145 ◽

2013 ◽

Vol 2013 ◽

pp. 1-7 ◽

Cited By ~ 2

Author(s):

Venkateswara Rao Surisetty ◽

Janusz Kozinski ◽

Ajay Kumar Dalai

Keyword(s):

Carbon Nanotubes ◽

Multiwalled Carbon Nanotubes ◽

Synthesis Gas ◽

Space Velocity ◽

Molar Ratio ◽

Higher Alcohols ◽

Multiwalled Carbon ◽

Ni Content ◽

Trimetallic Catalyst ◽

Higher Alcohols Synthesis

Alkali-promoted Ni-Co-Mo catalysts supported on multiwalled carbon nanotubes (MWCNTs) were prepared using 9 wt% K, 4.5 wt% Co, and 15 wt% Mo, whereas Ni content was varied from 0 to 6 wt%. The catalysts were extensively characterized and studied for higher alcohols synthesis from synthesis gas. Alkali-promoted trimetallic catalyst with 3 wt% Ni showed the highest total alcohols yield of 0.284 gm/(gm of cat./h), ethanol selectivity of 20%, and higher alcohols selectivity of 32% at 330°C and 9.0 MPa using gas hourly space velocity (GHSV) of 3.8 m3 (STP)/kg of catalyst/h and H2 to CO molar ratio of 1.25.

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Transformation of Gaseous Technical Mixture of the Alkanes and Alkenes Into Liquid Fraction Over Ni-HZSM-5 Obtained by Ionic Exchange

Revista de Chimie ◽

10.37358/rc.18.4.6232 ◽

2018 ◽

Vol 69 (4) ◽

pp. 938-943

Author(s):

Iuliean Vasile Asaftei ◽

Ion Sandu ◽

Neculai Catalin Lungu ◽

Adrian Florin Spac ◽

Maria Ignat

Keyword(s):

Catalytic Activity ◽

Ion Exchange ◽

Liquid Fraction ◽

Fixed Bed ◽

Liquid Product ◽

Space Velocity ◽

Bifunctional Catalyst ◽

Ni Catalyst ◽

Ionic Exchange ◽

Exchange Method

Paraffin�s and olefins in the cracked naphtha can be transformed into aromatics and iso-paraffins to reduce the olefins content as well to improve the octane number of the gasoline commercial fraction. In this work Ni-HZSM-5 bifunctional catalyst was prepared by ion exchange with Ni(NO3)2 aqueous solution. The activity of Ni-HZSM-5 (wt.% 1.34% Ni) catalyst prepared by ion exchange method was investigated in the conversion of light hydrocarbons resulted as by-products of petroleum refining process (mixtures of butenes and (normal + iso) butanes as main components). The obtained Ni-based catalyst has been compare with HZSM-catalyst. The conversion experiments have been performed in a fixed-bed stainless-steel reactor (Twin Reactor System Naky) at 450oC, under 4 atm. (over Ni-HZSM-5) and 8 atm. pressure (over HZSM-5), respectively and at a space velocity (WHSV) of 1h-1. The catalytic activity of (Ni-HZSM-5 catalyst) monitored over 10 catalytic tests (with regeneration of catalyst after each test) using a mixtures butanes-butylenes. The catalytic activity and selectivity towards liquid products - BTX aromatic hydrocarbons and oligo(iC5-iC10, nC5-nC10, ] C10) - depends on time streaming, composition of butanes-butylenes mixture and pressure. In the first hours of each test the aromatic BTX are the main component of the liquid product (connected with butylenes consume) and after that, the oligo fraction become predominant. The initial aromatization process described as dehydrocyclodimerization of alkanes and alkenes, principally to aromatics BTX and molecular hydrogen, is accompanied by oligomerization, isomerization, cracking and alkylation processes to form finally in the liquid phase product an excessively mixture of iso- and normal - C5 -C10 and ] C10 aliphatic hydrocarbons.

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An investigation on the influence of catalyst composition, calcination and reduction temperatures on Ni/MgO catalyst for dry reforming of methane

RSC Advances ◽

10.1039/c6ra15256b ◽

2016 ◽

Vol 6 (94) ◽

pp. 91603-91616 ◽

Cited By ~ 17

Author(s):

Muhammad Usman ◽

W. M. A. Wan Daud

Keyword(s):

Catalytic Activity ◽

Space Velocity ◽

Dry Reforming ◽

Dry Reforming Of Methane ◽

Catalyst Composition ◽

Ni Content ◽

High Space ◽

Very High ◽

High Space Velocity

Catalytic activity of Ni/MgO catalyst investigated at different Ni content (20, 40 and 80 wt%), calcination (450, 600 and 800 °C) and reduction temperatures (550 and 800 °C) for dry reforming reaction at very high space velocity.

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Evidence for ordered Fe3Ni

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100125981 ◽

1987 ◽

Vol 45 ◽

pp. 216-217

Author(s):

K.B. Reuter ◽

D.B. Williams ◽

J.I. Goldstein

Keyword(s):

Experimental Data ◽

Martensitic Transformation ◽

Electron Diffraction ◽

Room Temperature ◽

Direct Evidence ◽

Transformation Product ◽

Iron Meteorites ◽

X Ray ◽

Ni Content ◽

Temperature Transformation

In the Fe-Ni system, although ordered FeNi and ordered Ni3Fe are experimentally well established, direct evidence for ordered Fe3Ni is unconvincing. Little experimental data for Fe3Ni exists because diffusion is sluggish at temperatures below 400°C and because alloys containing less than 29 wt% Ni undergo a martensitic transformation at room temperature. Fe-Ni phases in iron meteorites were examined in this study because iron meteorites have cooled at slow rates of about 10°C/106 years, allowing phase transformations below 400°C to occur. One low temperature transformation product, called clear taenite 2 (CT2), was of particular interest because it contains less than 30 wtZ Ni and is not martensitic. Because CT2 is only a few microns in size, the structure and Ni content were determined through electron diffraction and x-ray microanalysis. A Philips EM400T operated at 120 kV, equipped with a Tracor Northern 2000 multichannel analyzer, was used.

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Fabrication of Carbon Nanotube Triode Using Helicon Plasma Cvd with Electroplated Nico Catalyst

MRS Proceedings ◽

10.1557/proc-772-m7.4 ◽

2003 ◽

Vol 772 ◽

Author(s):

Masakazu Muroyama ◽

Kazuto Kimura ◽

Takao Yagi ◽

Ichiro Saito

Keyword(s):

Carbon Nanotubes ◽

Carbon Nanotube ◽

Metal Catalyst ◽

Ni Catalyst ◽

Plasma Cvd ◽

Helicon Plasma ◽

Plasma Enhanced Cvd ◽

Turn On ◽

Aligned Carbon Nanotubes ◽

Vertically Aligned

AbstractA carbon nanotube triode using Helicon Plasma-enhanced CVD with electroplated NiCo catalyst has been successfully fabricated. Isolated NiCo based metal catalyst was deposited at the bottom of the cathode wells by electroplating methods to control the density of carbon nanotubes and also reduce the activation energy of its growth. Helicon Plasma-enhanced CVD (HPECVD) has been used to deposit nanotubes at 400°C. Vertically aligned carbon nanotubes were then grown selectively on the electroplated Ni catalyst. Field emission measurements were performed with a triode structure. At a cathode to anode gap of 1.1mm, the turn on voltage for the gate was 170V.

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Effect of Ni content on the Hardenability of a Bainitic Steel for Processing of Plastics

10.26678/abcm.cobem2017.cob17-1174 ◽

2017 ◽

Author(s):

José Britti Bacalhau ◽

Túlio Mumic Cunha ◽

Conrado Ramos Moreira Afonso

Keyword(s):

Bainitic Steel ◽

Ni Content

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Synthesis and study the Structural and electrical and mechanical properties of High Temperature Superconductor Tl0.5Pb0.5Ba2Can-1Cun-xNixO2n+3-δ Substituted with nickel oxide for n=3

Ibn AL- Haitham Journal For Pure and Applied Science ◽

10.30526/31.3.2024 ◽

2018 ◽

Vol 31 (3) ◽

pp. 26 ◽

Cited By ~ 4

Author(s):

Laheeb. A. Mohammed ◽

Kareem. A. Jasim

Keyword(s):

Nickel Oxide ◽

High Temperature Superconductor ◽

Sintering Temperature ◽

Concentration Effects ◽

High Tc ◽

Xrd Diffraction ◽

Ni Content ◽

High Tc Phase ◽

Pure Phases ◽

Critical Temperature Tc

on this research is to study the effect of nickel oxide substitution on the pure phases superconductor Tl0.5Pb0.5Ba2Can-1Cun-xNixO2n+3-δ (n=3) where x=(0,0.2,0.4,0.6,0.8.and 1.0). The specimens in this work were prepared with used procedure of solid state reaction with sintering temperature 8500C for 24 h .we used technical (4-prob)to calculated and the critical temperature Tc . The results of the XRD diffraction analysis showed that the structure for pure and doped phases was tetragonal with phases high-Tc phase (1223),(1212) and low-Tc phase (1202) and add to the presence of some impure phase. It was noted the value a=b,c the parameter of the lattice increment with the increment of Ni content. The increment of (NiO) concentration effects electrical resistivity, dielectric constant and the hardness.

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INVAR M93

Alloy Digest ◽

10.31399/asm.ad.fe0143 ◽

2008 ◽

Vol 57 (1) ◽

Keyword(s):

Fracture Toughness ◽

Low Temperature ◽

Physical Properties ◽

Tensile Properties ◽

Low Temperatures ◽

Bend Strength ◽

Temperature Performance ◽

Ni Content ◽

Precision Alloys ◽

Ni Alloy

Abstract Invar is an Fe-Ni alloy with 36% Ni content that exhibits the lowest expansion of known metals from very low temperatures up to approximately 230 deg C (445 deg F). Invar M93 is a cryogenic Invar with improved weldability. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear and bend strength as well as fracture toughness and fatigue. It also includes information on low temperature performance as well as forming and joining. Filing Code: FE-143. Producer or source: Metalimphy Precision Alloys.

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