Effect of molar ratio of water / ethanol on hydrogen selectivity in catalytic production of hydrogen using steam reforming of ethanol

2019 ◽  
Vol 44 (20) ◽  
pp. 9823-9829 ◽  
Author(s):  
Gülay Özkan ◽  
Başak Şahbudak ◽  
Göksel Özkan
Keyword(s):  
Steam Reforming ◽  
Molar Ratio ◽  
Steam Reforming Of Ethanol ◽  
Production Of Hydrogen ◽  
Hydrogen Selectivity

Steam-reforming of ethanol for hydrogen production

2011 ◽  
Vol 65 (3) ◽  
Author(s):  
Ahmed Bshish ◽  
Zahira Yaakob ◽  
Binitha Narayanan ◽  
Resmi Ramakrishnan ◽  
Ali Ebshish
Keyword(s):  
Hydrogen Production ◽  
Steam Reforming ◽  
Molar Ratio ◽  
Ethanol Conversion ◽  
Impregnation Method ◽  
Reaction Conditions ◽  
Oxide Supports ◽  
Steam Reforming Of Ethanol ◽  
Production Of Hydrogen ◽  
Hydrogen Selectivity

AbstractProduction of hydrogen by steam-reforming of ethanol has been performed using different catalytic systems. The present review focuses on various catalyst systems used for this purpose. The activity of catalysts depends on several factors such as the nature of the active metal catalyst and the catalyst support, the precursor used, the method adopted for catalyst preparation, and the presence of promoters as well as reaction conditions like the water-to-ethanol molar ratio, temperature, and space velocity. Among the active metals used to date for hydrogen production from ethanol, promoted-Ni is found to be a suitable choice in terms of the activity of the resulting catalyst. Cu is the most commonly used promoter with nickel-based catalysts to overcome the inactivity of nickel in the water-gas shift reaction. γ-Al2O3 support has been preferred by many researchers because of its ability to withstand reaction conditions. However, γ-Al2O3, being acidic, possesses the disadvantage of favouring ethanol dehydration to ethylene which is considered to be a source of carbon deposit found on the catalyst. To overcome this difficulty and to obtain the long-term catalyst stability, basic oxide supports such as CeO2, MgO, La2O3, etc. are mixed with alumina which neutralises the acidic sites. Most of the catalysts which can provide higher ethanol conversion and hydrogen selectivity were prepared by a combination of impregnation method and sol-gel method. High temperature and high water-to-ethanol molar ratio are two important factors in increasing the ethanol conversion and hydrogen selectivity, whereas an increase in pressure can adversely affect hydrogen production.

scholarly journals Sustainable Production of Hydrogen by Steam Reforming of Ethanol Using Cobalt Supported on Nanoporous Zeolitic Material

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1934
Author(s):  
Javier Francisco da Costa-Serra ◽  
Maria Teresa Navarro ◽  
Fernando Rey ◽  
Antonio Chica
Keyword(s):  
Steam Reforming ◽  
Zeolite Y ◽  
Cobalt Catalysts ◽  
Coke Deposition ◽  
Bet Surface Area ◽  
Ethanol Conversion ◽  
Y Zeolite ◽  
Steam Reforming Of Ethanol ◽  
Production Of Hydrogen ◽  
Hydrogen Selectivity

Cobalt catalysts supported on Y zeolite and mesoporized Y zeolite (Y-mod) have been studied in steam reforming of ethanol (SRE). Specifically, the effect of the mesoporosity and the acidity of the y zeolite as a support has been explored. Mesoporous were generated on Y zeolite by treatment with NH4F and the acidity was neutralized by Na incorporation. Four cobalt catalysts supported on Y zeolite have been prepared, two using Y zeolite without mesoporous (Co/Y, Co/Y-Na), and two using Y zeolite with mesoporous (Co/Y-mod and Co/Y-mod-Na). All catalysts showed a high activity, with ethanol conversion values close to 100%. The main differences were found in the distribution of the reaction products. Co/Y and Co/Y-mod catalysts showed high selectivity to ethylene and low hydrogen production, which was explained by their high acidity. On the contrary, neutralization of the acid sites could explain the higher hydrogen selectivity and the lower ethylene yields exhibited by the Co/Y-Na and Co/Y-mod-Na. In addition, the physicochemical characterization of these catalysts by XRD, BET surface area, temperature-programmed reduction (TPR), and TEM allowed to connect the presence of mesoporous with the formation of metallic cobalt particles with small size, high dispersion, and with high interaction with the zeolitic support, explaining the high reforming activity exhibited by the co/y-mod-Na sample as well as its higher hydrogen selectivity. It has been also observed that the formation of coke is affected by the presence of mesoporous and acidity. Both properties seem to have an opposite effect on the reforming catalyst, decreasing and increasing the coke deposition, respectively.

scholarly journals A highly efficient and stable Ni/SBA-15 catalyst for hydrogen production by ethanol steam reforming

2020 ◽  
Vol 45 ◽  
pp. 146867831989184
Author(s):  
Xia An ◽  
Jia Ren ◽  
Weitao Hu ◽  
Xu Wu ◽  
Xianmei Xie
Keyword(s):  
Steam Reforming ◽  
Photoelectron Spectroscopy ◽  
Nickel Nitrate ◽  
Molar Ratio ◽  
Linear Regression Method ◽  
Impregnation Method ◽  
X Ray ◽  
Nickel Sulfamate ◽  
Steam Reforming Of Ethanol ◽  
Production Of Hydrogen

The production of hydrogen by steam reforming of ethanol was carried out on SBA-15-supported nano NiO catalyst synthesized by the equivalent-volume impregnation method with two different Ni sources (nickel nitrate and nickel sulfamate). The catalyst was characterized by N2 adsorption–desorption, X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy to examine the physical and chemical properties. The activity tests were performed with the steam, with water/ethanol molar ratio ranging from 2:1 to 15:1, the N2 flow rate from 20 to 120 mL min−1 to determine the space-time, and the temperature range from 623 to 923 K on the two different Ni source catalysts. A favorable operating condition was established at 823 K using water/ethanol = 6 molar ratio and carrier gas (N2) flow of more than 50 mL min−1 for nickel nitrate source, but for nickel sulfamate source, the optimum temperature changed to 773 K and other conditions were the same as for the nickel nitrate source. After eliminating the influence of internal and external diffusion factors, an empirical power-law kinetic rate equation was derived from the experimental data. The non-linear regression method was used to estimate the kinetic parameter. The activation energy of the catalyst was then calculated, and the supported nickel nitrate and nickel sulfamate catalysts were 25.345 and 41.449 kJ mol−1, respectively, which was in agreement with the experimental and model-predicted results.

scholarly journals SOL-GEL DERIVED Co AND Ni BASED CATALYSTS: APPLICATION FOR STEAM REFORMING OF ETHANOL

2010 ◽  
Vol 8 (1) ◽  
pp. 47-53
Author(s):  
Haryo Satriya Oktaviano ◽  
Wega Trisunaryanti
Keyword(s):  
Steam Reforming ◽  
Catalyst Activity ◽  
Sol Gel ◽  
Lewis Acid Site ◽  
Morphological Properties ◽  
Molar Ratio ◽  
Gel Method ◽  
Sol Gel Method ◽  
Steam Reforming Of Ethanol ◽  
Ethanol Steam

Cobalt and nickel based catalysts for ethanol steam reforming have been prepared. Preparation of Na-Ni-Mo/C, Na-Co-Mo/C, K-Ni-Mo/C and K-Co-Mo/C have been carried out using sol-gel method by applying citric acid as complexion agent and source for support formation. Prepared catalyst via sol gel showed tailored morphological properties signed by tailored pore size distribution. The acidity of catalyst showed that all catalysts contain only Lewis acid site. The catalyst activity test was conducted by using semi flow method with molar ratio of ethanol : water = 0.33 at 400 oC   Keywords: sol-gel method, steam reforming, ethanol

Production of hydrogen for MC fuel cell by steam reforming of ethanol over MgO supported Ni and Co catalysts

2003 ◽  
Vol 4 (6) ◽  
pp. 259-268 ◽  
Author(s):  
S. Freni ◽  
S. Cavallaro ◽  
N. Mondello ◽  
L. Spadaro ◽  
F. Frusteri
Keyword(s):  
Fuel Cell ◽  
Steam Reforming ◽  
Co Catalysts ◽  
Steam Reforming Of Ethanol ◽  
Production Of Hydrogen ◽  
Supported Ni

Hydrogen from bioethanol: Catalytic honeycombs loaded with Co-Fe/ZnOfor small-scale energy applications

2011 ◽  
Vol 1326 ◽  
Author(s):  
Cristian Ledesma ◽  
Maria Roig ◽  
Jordi Llorca
Keyword(s):  
Steam Reforming ◽  
Molar Ratio ◽  
Small Scale ◽  
Reaction Products ◽  
Energy Applications ◽  
Steam Reforming Of Ethanol ◽  
One Step ◽  
Ethanol Steam ◽  
Urea Method

ABSTRACTCatalytic monoliths loaded with ZnO-supported Co-Fe catalysts were prepared in one step by the in situ urea method and tested in the ethanol steam reforming reaction to produce hydrogen. The most active and selective formulation was attained with a Fe/Co molar ratio between 0.05 and 0.1, which showed negligible amounts of methane among the reaction products, thus offering an active and selective material for the low-temperature steam reforming of ethanol for small-scale energy applications.

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