Production of hydrogen by ethanol steam reforming over nickel-metal oxide catalysts prepared via urea-nitrate combustion method

Abstract

SUMMARYA series of Ni/MgO catalysts have been prepared by a urea-nitrate combustion method, studied for the ethanol steam reforming, and compared with Ni/ZnO and Ni/Al 2 O 3 . The results show that Ni/MgO is superior to the latter two types of catalysts, especially in terms of H 2 yield. Influential factors, including Ni loading, temperature, water-to-ethanol molar ratio, and liquid hourly space velocity, are investigated with the Ni/MgO catalyst. The conversions are always complete at temperatures above 773 K, regardless of the changes of the other reaction conditions. The hydrogen yield increases with increasing temperature and H 2 O/C 2 H 5 OH molar ratios, with up to 75% being obtained at 873 K, liquid hourly space velocity (LHSV) of 5.0 ml g -1 h -1 and H 2 O/C 2 H 5 OH molar ratio of 10.

Hydrogen production from ethanol steam reforming over Ni/SiO2catalysts: A comparative study of traditional preparation and microwave modification methods

“…Ethanol conversions over NiSi‐im catalyst was slightly lower than that over other catalysts. Similar results were also reported over other Ni catalysts in SRE . The measurement results were lower than thermodynamic analysis that at T > 500 K ethanol conversion is higher than 0.99 at all water/ethanol molar ratios (0–10) .…”

“…As shown in Figure , high temperature favors SR due to the endothermic nature of the SR process. The hydrogen yield increased with increasing reaction temperature and decreasing molar ratio of ethanol to water . Because of the four prepared catalysts possessing some excellent advantages (such as large specific surface, high surface energy, uniform pore size distribution, moderately acid strong sites and a lot of surface active centers), the four prepared catalysts show high surface activity, high selectivity to H 2 and high catalytic efficiency for hydrogen production from ethanol SR. After the catalyst was treated by microwave modification, the performance of the catalysts was further improved.…”

Hydrogen production by steam reforming of ethanol over Co3O4/La2O3/CeO2 catalysts synthesized by one-step polymerization method

“…Especially, γ-Al 2 O 3 is extensively used due to its acidic properties, high surface area and relatively low cost [16]. However, the acidic character of alumina may promote the ethanol dehydration in the SRE (producing ethylene), which can lead to high carbon deposition rates, therefore, oxides such as ZrO 2 [17], CeO 2 [18,19], MgO [20,21] and modified zeolites [22,23] have been recently studied as promising substituents for conventional supports in the preparation of Ni and Co catalysts for the SRE. CeO 2 is used as an additive, a promoter or even as catalytic support, due to its redox properties, basic character, and its fcc structure provided with oxygen vacancies (which provide high oxygen-mobility) which improves the catalytic performance in reforming reaction and prevents the carbon deposits on the catalytic surface.…”

A combined thermodynamic and experimental study on chemical-looping ethanol reforming with carbon dioxide capture for hydrogen generation

“…Among many potential sources for H 2 generation, ethanol (C 2 H 5 OH), which is renewable fuel, is considered to be one of the ideal fuels for H 2 source. C 2 H 5 OH can be converted into H 2 through steam reforming [2][3][4][5][6], partial oxidation [7], autothermal reforming (or oxidative reforming) [8] and dry reforming (or CO 2 reforming) [9]. If pure H 2 is the target product, the high content of CO and CO 2 , accompanied in the process, must be separated before application.…”