Tri-Reforming of Methane over Pt Modified Ni/MgO Catalysts under Atmospheric Pressure – Thermal Distribution in the Catalyst Bed

2012 ◽  
Vol 252 ◽  
pp. 255-258 ◽  
Author(s):  
Hong Tao Jiang ◽  
Hui Quan Li ◽  
Hao Fan
Keyword(s):  
Temperature Profile ◽  
Atmospheric Pressure ◽  
Preparation Method ◽  
Fixed Bed ◽  
Space Velocity ◽  
Methane Reforming ◽  
Thermal Distribution ◽  
Sequence Method ◽  
Catalysts Preparation

Thermal distribution in catalyst bed was investigated for the fixed-bed tri-reforming of methane over Pt modified Ni/MgO catalysts under atmospheric pressure, 850 °C, and space velocity of 2000−20000 h−1. The effects of the W/F on the thermal distribution of different catalysts were examined. The results indicated that for Pt modified Ni/MgO catalysts, the temperature profile depended on catalysts preparation method. According to the thermal distribution, for Pt modified Ni/MgO catalysts prepared by sequence method, the catalyst bed can be divided into tow zones: auto-thermo reforming zone and oxygen absent zone. Methane reforming proceeds in both zones together.

Effects of Cu and K Promoters on the Catalytic Performance of Iron-Based Nanocatalyst for Fischer-Tropsch Synthesis

2013 ◽  
Vol 832 ◽  
pp. 15-20 ◽  
Author(s):  
Sara Faiz Hanna Tasfy ◽  
Noor Asmawati Mohd Zabidi ◽  
Duvvuri Subbarao
Keyword(s):  
Atmospheric Pressure ◽  
Fixed Bed ◽  
Space Velocity ◽  
Catalytic Performance ◽  
Reactant Ratio ◽  
Impregnation Method ◽  
Fischer Tropsch ◽  
Heavy Hydrocarbons ◽  
Co Conversion ◽  
Iron Based

Iron-based nanocatalyst was prepared via impregnation method on SiO2 support. The effects of promoters, namely, K and Cu, on the physical properties and catalytic performance in FTS have been investigated. The FTS performance of the synthesized nanocatalysts was examined in a fixed-bed microreactor at temperature of 523K, atmospheric pressure, 1.5 reactant ratio (H2/CO) and space velocity of 3L/g-cat.h. In FTS reaction, Cu promoter resulted in a lower CO conversion and C5+ hydrocarbons selectivity but higher selectivity to the lighter hydrocarbons (C1-C4) comparedto those obtained using the K promoter. Higher CO conversion (28.9%) and C5+ hydrocarbons selectivity (54.4%) were obtained using K as a promoter compared to that of Cu promoter. However, the K-promoted nanocatalyst resulted in a lower CO conversion but higher selectivity of the heavy hydrocarbons (C5+) compared to those obtained using the un-promoted nanocatalyst.

scholarly journals Investigation of Butane-butylene Technical Mixtures Transformation Over Modified Microporous Materials Prepared by Ion Exchange Method Into Liquid Fraction Rich in Aromatic Hydrocarbons

2019 ◽  
Vol 70 (6) ◽  
pp. 2004-2009
Author(s):  
Iuliean Vasile Asaftei ◽  
Neculai Catalin Lungu ◽  
Maria Ignat ◽  
Ion Sandu
Keyword(s):  
Catalytic Activity ◽  
Ion Exchange ◽  
Atmospheric Pressure ◽  
Liquid Fraction ◽  
Fixed Bed ◽  
Space Velocity ◽  
Exchange Method ◽  
Structure Morphology ◽  
Stainless Steel Reactor ◽  
Ion Exchange Method

The Zn and Ni were introduced into HZSM-5 zeolite by ion exchange method with aqueous solutions of Zn(NO3)2 and Ni(NO3)2, to investigate the catalytic activity and selectivity of modified Zn-HZSM-5 and Ni-HZSM-5 catalysts for conversion of butane-butylenes technical mixtures in a fixed-bed stainless-steel reactor (Twin Reactor System Naky) at 450�C, at atmospheric pressure for Zn-HZSM-5 and at 4 atm. total pressure for Ni-HZSM-5 and at a space velocity (WHSV) of 1h-1. The catalysts were characterized using XRD, SEM, and NH3-TPD analysis for their structure, morphology and acidity. The catalytic activity of the same catalyst were examined during over 10 catalytic tests (with regeneration of catalyst after each test) using mixtures of butanes-butylenes.

Dimethyldisulphide Hydrodesulphurization on NiCoMo / Al2O3 Catalyst

2017 ◽  
Vol 68 (7) ◽  
pp. 1496-1500
Author(s):  
Rami Doukeh ◽  
Mihaela Bombos ◽  
Ancuta Trifoi ◽  
Minodora Pasare ◽  
Ionut Banu ◽  
...  
Keyword(s):  
Good Accuracy ◽  
Fixed Bed ◽  
Continuous System ◽  
Space Velocity ◽  
Molar Ratio ◽  
Catalytic Reactor ◽  
Liquid Hourly Space Velocity ◽  
Hydrodesulfurization Process ◽  
Al2o3 Catalyst ◽  
Simplified Kinetic Model

Hydrodesulphurization of dimethyldisulphide was performed on Ni-Co-Mo /�-Al2O3 catalyst. The catalyst was characterized by determining the adsorption isotherms, the pore size distribution and the acid strength. Experiments were carried out on a laboratory echipament in continuous system using a fixed bed catalytic reactor at 50-100�C, pressure from 10 barr to 50 barr, the liquid hourly space velocity from 1h-1 to 4h-1 and the molar ratio H2 / dimethyldisulphide 60/1. A simplified kinetic model based on the Langmuir�Hinshelwood theory, for the dimethyldisulphide hydrodesulfurization process of dimethyldisulphide has been proposed. The results show the good accuracy of the model.

Comparative Study on the Kinetic Modeling of the Oxidative Coupling of Methane in Laboratory and Bench Scales

2008 ◽  
Vol 3 (1) ◽  
Author(s):  
Nakisa Yaghobi ◽  
Mir Hamid Reza Ghoreishy
Keyword(s):  
Kinetic Models ◽  
Oxidative Coupling ◽  
Consumption Rate ◽  
Linear Regression Analysis ◽  
Fixed Bed ◽  
Space Velocity ◽  
Oxidative Coupling Of Methane ◽  
Power Law Model ◽  
Fixed Bed Reactors ◽  
Rate Of Reaction

The aim of this work is to develop and compare kinetic models for the oxidative coupling of methane (OCM) based on the gas hourly space velocity (GHSV) value and CH4/O2 ratio in two scales: laboratory and bench. The experiments were carried out in tubular fixed bed reactors at 1023 K, using 0.7-1.5 g and 30 g of perovskite titanate as the reaction catalyst for laboratory and bench scales, respectively. The various GHSVs (8000, 12000, 17000 h-1) and (3400, 4300, 5200 h-1) and methane to oxygen ratios (1, 2, 3, 4, 7.5) and (2, 2.5, 3) were selected for laboratory and bench scales, respectively. We have proposed a mechanism in which the consumption rate of methane is always twice of production rate of C2. A power law model was assumed for rate of reaction in terms of partial pressure of oxygen and methane. Using a linear regression analysis, the kinetic models were determined. Comparison of the calculated rate of reaction with the experimentally measured data confirmed the accuracy and applicability of the developed model for both scales.

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%.

High-Spatial-Resolution OH Rotational Temperature Measurements in an Atmospheric-Pressure Flame Using an Indium-Based Resonance Ionization Detector

1995 ◽  
Vol 49 (5) ◽  
pp. 655-659 ◽  
Author(s):  
Giuseppe A. Petrucci ◽  
Denise Imbroisl ◽  
Robert D. Guenard ◽  
Benjamin W. Smith ◽  
Jame D. Winefordner
Keyword(s):  
Temperature Profile ◽  
Spatial Resolution ◽  
Atmospheric Pressure ◽  
High Spatial Resolution ◽  
Rotational Temperature ◽  
Resonance Ionization ◽  
Excitation Spectra ◽  
Excitation Beam ◽  
Flame Region ◽  
Collisional Ionization

The use of a resonance ionization photon detector (RID) is described for the measurement of flame temperatures with a spatial resolution of less than 100 μm. The detector, based on the two-step excitation of indium atoms, with subsequent collisional ionization, was used to record rotational excitation scans of OH in an atmospheric-pressure acetylene/air flame. The OH excitation spectra were recorded by scanning an “excitation” laser in the A2σ+ ← X2II i (1, 0) vibronic band in the wavelength range, 281–288 nm, while simultaneously illuminating the same flame region with the “detection” laser, tuned to the 6 p2 P3/2 → 10 d2. D5/2 excited-state transition of In at 786.44 nm. The excitation and detection laser beams were made orthogonal in the flame, defining the resolution to be limited by the waist of the excitation beam (100 μm), whose diameter was always smaller than the detection laser beam. A temperature profile of the flame is recorded with the use of both the RID approach and a more conventional laser-induced fluorescence (LIF) approach for comparison. A more structured temperature profile is recorded with the RID owing to its high spatial resolution, whereas the LIF method, which is inherently a line-of-sight method, produces a rather featureless temperature distribution across the flame. Anomalously high flame temperatures were recorded at the flame edge with the RID. The cause of these high flame temperatures has not been determined.

Production of Hydrogen-Rich Gas Through Pyrolysis of Biomass in a Two-Stage Reactor

2004 ◽  
Author(s):  
Guanyi Chen ◽  
Qiang Li ◽  
Xiaoyang Lv ◽  
Na Deng ◽  
Lifei Jiao
Keyword(s):  
Rice Straw ◽  
Fixed Bed ◽  
Space Velocity ◽  
Corn Stalk ◽  
Two Stage ◽  
Gaseous Products ◽  
Production Of Hydrogen ◽  
Gas Space ◽  
Energy Products ◽  
Pyrolysis Of Biomass

Biomass is quite abundant in the world, particularly in some countries like China. China has large quantities of straw and/or stalk-origin biomass resources and the attention is currently being paid to the exploitation of these resources to produce energy products via different technical solutions, among of which pyrolysis of biomass to produce hydrogen-rich gas is very promising as hydrogen is a very clear energy carrier. In this work, pyrolysis of rice straw, corn stalk and sawdust was carried out in a two-stage reactor (the first-stage reactor is a conventional fixed-bed pyrolyser, and the second-stage reactor is a catalytic fixed bed) to produce hydrogen-rich gas. The effect of catalytic bed on the pyrolysis behaviour have been investigated, with the emphasis on final product particularly hydrogen. The operation of the catalytic reactor appears significant in promoting biomass pyrolysis towards the production of gaseous products, especially hydrogen. At 750°C of the pyrolyser with rice straw as fuel, the use of the catalytic bed leads to the increases of gas yield from 0.41 Nm3/kg to 0.50 Nm3/kg, approximately 22% increase, and of H2 concentration from 33.79% to 50.80% in volume, approximately 50.3% increase, respectively. Compared with calcined dolomite, fresh nickel-based catalyst shows stronger catalytic effect on the pyrolysis of rice straw as its use in the catalytic bed results in the increase of gas yield from 0.41 Nm3/kg to 0.56 Nm3/kg, approximately 36.6% increase, and the increase of H2 concentration from 33.79% to 59.55% in volume, approximately 76.2% increase. Furthermore, two catalysts follow the same trend for the pyrolysis of corn stalk and sawdust. At temperature of 815°C, catalysts also follow the same trend. Catalytic bed can significantly reduce the level of tar which is carried out with the producer gas, to less than 1% of original level. Catalyst load or gas space velocity (hourly) has the influence on the gas yield and H2 concentration. 30% of load, i.e. gas space velocity (hourly) 0.9 × 104 h−1, appears reasonable. Beyond that, gas yield and H2 concentration remain almost unchanged.

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