Hydrogen Production by a Steam Reforming Reactor for Heavy Hydrocarbons

2011 ◽  
Author(s):  
Yasutaka Fujimoto ◽  
Toshio Shinoki ◽  
Hirochika Tanigawa ◽  
Jiro Funaki ◽  
Katsuya Hirata
Keyword(s):  
Steam Reforming ◽  
Thermal Equilibrium ◽  
Space Velocity ◽  
Conversion Ratio ◽  
Equilibrium Theory ◽  
Temperature Profiles ◽  
Heavy Hydrocarbons ◽  
Liquid Hourly Space Velocity ◽  
High Conversion Ratio ◽  
Thermal Diffuser

The authors develop a small and simple steam-reforming reactor in a home-use size for n-dodecane as a heavy-hydrocarbons fuel. Under the thermal condition controlled by electric heaters and a gas burner with a thermal diffuser, the authors measure the inside-temperature profile and the hydrogen-molecule ratio (concentration) RH2, together with the molecule ratios RCH4, RCO and RCO2 of other main gas components such as CH4, CO and CO2, respectively. Besides, the authors conduct numerical simulations based on a thermal-equilibrium theory, in addition to experiments. As a result, the authors successfully achieve suitable inside-temperature profiles. And, the effects of the liquid-hourly-space velocity LHSV upon RH2, RCH4, RCO and RCO2 are shown, experimentally. For LHSV ≤ 1, the experimental results agree well with the thermal equilibrium theory. This is in consistent with high conversion ratio XC12H26 ≳ 80%. Furthermore, the authors reveal the effects of the temperature T inside the reactor upon the molecule ratios, comparing with the thermal-equilibrium theory.

Hydrogen Production From Various Heavy Hydrocarbons by Steam Reforming

2017 ◽  
Author(s):  
Yasuyoshi Takeda ◽  
Masaki Kusumi ◽  
Masaaki Kamizono ◽  
Toshio Shinoki ◽  
Hirochika Tanigawa ◽  
...  
Keyword(s):  
Steam Reforming ◽  
Catalyst Layer ◽  
Space Velocity ◽  
Conversion Ratio ◽  
Temperature Profiles ◽  
Heavy Hydrocarbons ◽  
Upper Limit ◽  
Liquid Hourly Space Velocity ◽  
Thermochemical Equilibrium ◽  
The Common

The authors develop a small and simple steam-reforming reactor in a home-use size for such various heavy-hydrocarbons fuels as n-octane, n-decane, n-tetradecane and n-hexadecane in addition to n-dodecane, and measure the inside-temperature profile and the molar fractions of main gas components such as H2, CH4, CO and CO2. As a result, the authors successfully achieve suitable inside-temperature profiles. Namely, temperature almost-linearly increases in the downstream direction along a reactor, under such two conditions as 600–950 K at the upstream end of the catalyst-layer bed in the reactor and as less-than 1,070 K everywhere in the reactor. And, the authors reveal the effects of the liquid-hourly space velocity (LHSV) upon the molar fractions, a conversion ratio and reforming efficiencies for various heavy-hydrocarbons fuels. All the molar fractions, which agree well with thermochemical-equilibrium theory, are approximately independent of LHSV. The conversion ratio is about 90 % for LHSV ≤ 0.6 h−1, and monotonically decreases with increasing LHSV for LHSV > 0.6 h−1. Then, each reforming efficiency always attains the maximum for LHSV ≈ 0.6 h−1 being independent of fuels. This suggests the common upper limit of LHSV for practically-suitable operation.

Hydrogen Production From Petroleum Hydrocarbons

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Toshio Shinoki ◽  
Masaaki Kamizono ◽  
Koshi Katagiri ◽  
Masaki Kusumi ◽  
Yasuyoshi Takeda ◽  
...  
Keyword(s):  
Petroleum Hydrocarbons ◽  
Catalyst Layer ◽  
Space Velocity ◽  
Conversion Ratio ◽  
Temperature Profiles ◽  
Heavy Hydrocarbons ◽  
Liquid Hourly Space Velocity ◽  
Thermochemical Equilibrium ◽  
The Common ◽  
Test Use

Abstract The authors develop a small and simple steam-reforming reactor in a home-use size for such various heavy-hydrocarbons fuels as n-octane, n-decane, n-tetradecane, and n-hexadecane in addition to n-dodecane and measure the inside-temperature profile and the molar fractions of main-gas components such as H2, CH4, CO, and CO2. This reactor is designed only for laboratory-test use, not for a commercial product. As a result, the authors successfully achieve suitable inside-temperature profiles, namely, temperature almost linearly increases in the downstream direction along a reactor, under two conditions such as 600–950 K at the upstream end of the catalyst-layer bed in the reactor and less than 1070 K everywhere in the reactor. And, the authors reveal the effects of the liquid-hourly space velocity (LHSV) upon the molar fractions, a conversion ratio and reforming efficiencies for various heavy-hydrocarbons fuels. All the molar fractions, which agree well with thermochemical-equilibrium theory, are approximately independent of LHSV. The conversion ratio is about 90% for LHSV ≤ 0.6 h−1 and monotonically decreases with increasing LHSV for LHSV > 0.6 h−1. Then, each reforming efficiency always attains the maximum for LHSV ≈ 0.6 h−1 being independent of fuels. This suggests the common upper limit of LHSV for practically suitable operation.

Hydrogen Production by Catalytic Steam Reforming of Model Compounds of Biomass Fast Pyrolysis Oil

2010 ◽  
Vol 1279 ◽  
Author(s):  
P. Lan ◽  
Q. L. Xu ◽  
L. H. Lan ◽  
Y. J. Yan ◽  
J. A. Wang
Keyword(s):  
Hydrogen Production ◽  
Steam Reforming ◽  
Space Velocity ◽  
Molar Ratio ◽  
Hydrogen Yield ◽  
Pyrolysis Oil ◽  
Model Compounds ◽  
Liquid Hourly Space Velocity ◽  
Bio Oil ◽  
Catalytic Steam Reforming

AbstractA Ni/MgO-La2O3-Al2O3 catalyst with Ni as active component, Al2O3 as support, MgO and La2O3 as additives was prepared and its catalytic activity was evaluated in the process of hydrogen production from catalytic steam reforming of bio-oil. In the catalytic evaluation, some typical components present in bio-oil such as acetic acid, butanol, furfural, cyclopentanone and m-cresol were mixed following a certain proportion as model compounds. Reaction parameters like temperature, steam to carbon molar ratio and liquid hourly space velocity were studied with hydrogen yield as index. The optimal reaction conditions were obtained as follows: temperature 750-850 °C, steam to carbon molar ratio 5-9, liquid hourly space velocity 1.5-2.5 h-1. The maximum hydrogen yield was 88.14%. The carbon deposits were formed on the catalyst surface but its content decreased as reaction temperature increased in the bio-oil steam reforming process.

Steam Reforming of Benzene over Modified Ni/olivine Catalyst

2011 ◽  
Vol 236-238 ◽  
pp. 389-393
Author(s):  
Xiao Qin Yang ◽  
Shao Ping Xu ◽  
Shuang Quan Zhang
Keyword(s):  
Catalytic Activity ◽  
Reaction Temperature ◽  
Steam Reforming ◽  
Catalyst Activity ◽  
Space Velocity ◽  
Ni Catalysts ◽  
Physiochemical Properties ◽  
Mo Catalyst ◽  
Liquid Hourly Space Velocity ◽  
Aluminate Cement

Steam reforming of benzene was carried out over Ni catalysts supported on modified olivine (MO). The MO was prepared by moulding olivine powder with calcium aluminate cement followed by calcination. It was found that calcination temperature of the support significantly influenced its physiochemical properties and the catalyst activity. The effects of reaction temperature, steam to carbon ratio (S/C) and liquid hourly space velocity (LHSV) on the catalytic activity were studied. The Ni/MO catalyst was shown to be very active at the reaction temperature above 750 °C. A close to 100% C-conversion was obtained at the conditions with reaction temperature 800 °C, LHSV 0.8 h–1and S/C ratio 2.5. No obvious deactivation of the catalyst was observed during 500 min stability test.

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.

Numerical Analysis of the Heat and Mass Transfer Characteristics in an Autothermal Methane Reformer

2010 ◽  
Vol 7 (5) ◽  
Author(s):  
Joonguen Park ◽  
Shinku Lee ◽  
Sunyoung Kim ◽  
Joongmyeon Bae
Keyword(s):  
Mass Transfer ◽  
Numerical Analysis ◽  
Heat And Mass Transfer ◽  
Steam Reforming ◽  
Space Velocity ◽  
Reaction Model ◽  
Operating Conditions ◽  
Local Thermal Equilibrium ◽  
Inlet Temperature ◽  
Transfer Characteristics

This paper discusses a numerical analysis of the heat and mass transfer characteristics in an autothermal methane reformer. Assuming local thermal equilibrium between the bulk gas and the surface of the catalyst, a one-medium approach for the porous medium analysis was incorporated. Also, the mass transfer between the bulk gas and the catalyst’s surface was neglected due to the relatively low gas velocity. For the catalytic surface reaction, the Langmuir–Hinshelwood model was incorporated in which methane (CH4) is reformed to hydrogen-rich gases by the autothermal reforming (ATR) reaction. Full combustion, steam reforming, water-gas shift, and direct steam reforming reactions were included in the chemical reaction model. Mass, momentum, energy, and species balance equations were simultaneously calculated with the chemical reactions for the multiphysics analysis. By varying the four operating conditions (inlet temperature, oxygen to carbon ratio (OCR), steam to carbon ratio, and gas hourly space velocity (GHSV)), the performance of the ATR reactor was estimated by the numerical calculations. The SR reaction rate was improved by an increased inlet temperature. The reforming efficiency and the fuel conversion reached their maximum values at an OCR of 0.7. When the GHSV was increased, the reforming efficiency increased but the large pressure drop may decrease the system efficiency. From these results, we can estimate the optimal operating conditions for the production of large amounts of hydrogen from methane.

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.

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