Sorption-enhanced hydrogen production by steam reforming of ethanol over mesoporous Co/CaO Al 2 O 3 xerogel catalysts: Effect of Ca/Al molar ratio

2017 ◽  
Vol 42 (9) ◽  
pp. 5886-5898 ◽  
Author(s):  
Seung Ju Han ◽  
Ji Hwan Song ◽  
Jaekyeong Yoo ◽  
Seungwon Park ◽  
Ki Hyuk Kang ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Steam Reforming ◽  
Molar Ratio ◽  
Steam Reforming Of Ethanol

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.

Hydrogen production by steam reforming of ethanol over Ni/Al 2 O 3 -La 2 O 3 xerogel catalysts

2017 ◽  
Vol 434 ◽  
pp. 123-133 ◽  
Author(s):  
Ji Hwan Song ◽  
Sangbeom Yoo ◽  
Jaekyeong Yoo ◽  
Seungwon Park ◽  
Min Yeong Gim ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Steam Reforming ◽  
Steam Reforming Of Ethanol

Physical-Chemical and Thermodynamic Analyses of Ethanol Steam Reforming for Hydrogen Production

2006 ◽  
Vol 3 (3) ◽  
pp. 346-350 ◽  
Author(s):  
Antonio Carlos Caetano de Souza ◽  
José Luz-Silveira ◽  
Maria Isabel Sosa
Keyword(s):  
Hydrogen Production ◽  
Steam Reforming ◽  
Production Efficiency ◽  
Physical Chemical ◽  
Steam Reforming Of Ethanol ◽  
Thermodynamic Conditions ◽  
High Production ◽  
Exergetic Analysis ◽  
Global Reaction ◽  
Technical Features

Steam reforming is the most usual method of hydrogen production due to its high production efficiency and technological maturity. The use of ethanol for this purpose is an interesting option because it is a renewable and environmentally friendly fuel. The objective of this article is to present the physical-chemical, thermodynamic, and exergetic analysis of a steam reformer of ethanol, in order to produce 0.7Nm3∕h of hydrogen as feedstock of a 1kW PEMFC. The global reaction of ethanol is considered. Superheated ethanol reacts with steam at high temperatures producing hydrogen and carbon dioxide, depending strongly on the thermodynamic conditions of reforming, as well as on the technical features of the reformer system and catalysts. The thermodynamic analysis shows the feasibility of this reaction in temperatures about 206°C. Below this temperature, the reaction trends to the reactants. The advance degree increases with temperature and decreases with pressure. Optimal temperatures range between 600 and 700°C. However, when the temperature attains 700°C, the reaction stability occurs, that is, the hydrogen production attains the limit. For temperatures above 700°C, the heat use is very high, involving high costs of production due to the higher volume of fuel or electricity used. The optimal pressure is 1atm., e.g., at atmospheric pressure. The exergetic analysis shows that the lower irreversibility is attained for lower pressures. However, the temperature changes do not affect significantly the irreversibilities. This analysis shows that the best thermodynamic conditions for steam reforming of ethanol are the same conditions suggested in the physical-chemical analysis.

scholarly journals Steam reforming of ethanol for hydrogen production: influence of catalyst composition (Ni/Al2O3, Ni/Al2O3–CeO2, Ni/Al2O3–ZnO) and process conditions

2021 ◽  
Vol 132 (2) ◽  
pp. 907-919
Author(s):  
O. Shtyka ◽  
Z. Dimitrova ◽  
R. Ciesielski ◽  
A. Kedziora ◽  
G. Mitukiewicz ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Steam Reforming ◽  
Catalyst Stability ◽  
Feed Ratio ◽  
Ethanol Conversion ◽  
Process Conditions ◽  
Catalyst Activation ◽  
Catalyst Composition ◽  
Activity Measurements ◽  
Steam Reforming Of Ethanol

AbstractEthanol steam reforming was studied over Ni supported catalysts. The effects of support (Al2O3, Al2O3–ZnO, and Al2O3–CeO2), metal loading, catalyst activation method, and steam-to-ethanol molar feed ratio were investigated. The properties of catalysts were studied by N2 physisorption, TPD-CO2, X-ray diffraction, and temperature programmed reduction. After activity tests, the catalysts were analyzed by TOC analysis. The catalytic activity measurements showed that the addition either of ZnO SSor CeO2 to alumina enhances both ethanol conversion and promotes selectivity towards hydrogen formation. The same effects were observed for catalysts with higher metal loadings. High process temperature and high water-to-ethanol ratio were found to be beneficial for hydrogen production. An extended catalyst stability tests showed no loss of activity over 50 h on reaction stream. The TOC analysis of spent catalysts revealed only insignificant amounts of carbon deposit.

Hydrogen production by steam reforming of ethanol over Ni-based catalysts promoted with noble metals

2009 ◽  
Vol 190 (2) ◽  
pp. 525-533 ◽  
Author(s):  
Luciene P.R. Profeti ◽  
Joelmir A.C. Dias ◽  
José M. Assaf ◽  
Elisabete M. Assaf
Keyword(s):  
Hydrogen Production ◽  
Steam Reforming ◽  
Noble Metals ◽  
Steam Reforming Of Ethanol
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