Micro Channel Structure With Strengthened Rough Surface in an Ethanol Reforming Hydrogen Generator

2007 ◽  
Author(s):  
Dashi Su ◽  
Yong Tang ◽  
Mingqiang Pan
Keyword(s):  
Hydrogen Production ◽  
Rough Surface ◽  
Production Efficiency ◽  
Fixed Bed ◽  
Channel Structure ◽  
Microchannel Reactor ◽  
Energy And Environment ◽  
Ethanol Reforming ◽  
Environment Problem ◽  
Steam Reforming Of Ethanol

The combination of the hydrogen production from ethanol and microchannel technology can provide a portable hydrogen resource for fuel cell, which will effectively solve the energy and environment problem. This paper introduces a new surface structure — microchannel structure with strengthened rough surface (MCSWSRS) which has a feature of strongly transferring heat in microchannel. The MCSWSRS depends not only the dimension effect of this structure but also the special rough surface to strengthen heat transmission, so MCSWSRS transfers more heat than the smooth structure. Based on the heat strengthening transmission mechanism of MCSWSRS and the microchannel theory, a new kind of microchannel reactor was built and its heat strengthening transmission property has been analyzed. When the reacting temperature of microchannel reactor was 330°C and catalyst was Ni/La2O3, properties of MCSWSRS were experimented in the system of hydrogen from steam reforming of ethanol. The experimentation shows that hydrogen production efficiency of this microchannel reactor with MCSWSRS was 9% higher than that of the fixed bed tube reactor under the same reacting conditions. The results show that the MCSWSRS in reactor is feasible and advantageous in practice.

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 Ca-Modified Co/SBA-15 Catalysts for Hydrogen Production through Ethanol Steam Reforming

2013 ◽  
Vol 24 ◽  
pp. 1-16 ◽  
Author(s):  
Chen-Bin Wang ◽  
Siao Wun Liu ◽  
Kuan Fu Ho ◽  
Hsin Hua Huang ◽  
Chih Wei Tang ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Steam Reforming ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Coke Deposition ◽  
Incipient Wetness Impregnation ◽  
Hydrogen Yield ◽  
Impregnation Method ◽  
Steam Reforming Of Ethanol ◽  
Incipient Wetness

Hydrogen production through steam reforming of ethanol (SRE) over the Ca-modified Co/SBA-15 catalysts was studied herein to evaluate the catalytic activity, stability and the behavior of coke deposition. The Ca-modified SBA-15 supports were prepared from the Ca(NO3)2·4H2O (10 wt%) which was incorporated to SBA-15 by incipient wetness impregnation (assigned as Ca/SBA-15) and direct hydrothermal (assigned as Ca-SBA-15) method. The active cobalt species from the Co(NO3)2·6H2O (10 wt%) was loaded to SiO2, SBA-15 and modified-SBA-15 supports with incipient wetness impregnation method to obtain the cobalt catalysts (named as Co/SiO2, Co/SBA-15, Co-Ca/SBA-15 and Co/Ca-SBA-15, respectively). The prepared catalysts were characterized by using X-ray diffraction (XRD), temperature programmed reduction (TPR), transmission electron microscopy (TEM) and BET. The catalytic performance of the SRE reaction was evaluated in a fixed-bed reactor. The results indicated that the Co/Ca-SBA-15 catalyst was preferential among these catalysts and the ethanol can be converted completely at 375 °C. The hydrogen yield (YH2) approached 4.76 at 500 °C and less coke deposited. Further, the long-term stability test of this catalyst approached 100 h at 500 °C and did not deactivate.

Hydrogen Production from Ethanol Steam Reforming Using Ce- and La- Modified Mesoporous MCM-41 Supported Nickel-Based Catalysts

2019 ◽  
Vol 17 (8) ◽  
Author(s):  
Lida Rahmanzadeh ◽  
Majid Taghizadeh
Keyword(s):  
Hydrogen Production ◽  
Steam Reforming ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Ethanol Conversion ◽  
Steam Reforming Of Ethanol ◽  
Hydrogen Selectivity ◽  
Temperature Programmed ◽  
Adsorption Desorption ◽  
Mcm 41

Abstract Mesoporous MCM-41 containing different amounts of nickel (10, 15 and 20 wt%) and Ce and/or La promoters were prepared by hydrothermal and wet-impregnation methods. The catalysts were characterized by means of temperature-programmed reduction (TPR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), N2 adsorption-desorption, Fourier transform infrared (FT-IR) spectroscopy, and thermogravimetric (TGA) analyses. Then, the catalysts were tested for hydrogen production via steam reforming of ethanol in a fixed bed reactor. Hydrogen selectivity and ethanol conversion over Ni/MCM-41 catalyst were 69.6 % and 94 %, respectively. The best catalytic results were obtained with Ce-Ni/MCM-41 catalyst, i. e. 94 % ethanol conversion and 76.5 % hydrogen selectivity. These results remained constant about 90 h time on stream and ethanol conversion decreased to 87 % after 120 h.

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
Sign in / Sign up

Export Citation Format

Share Document