HYDROGEN PERMEABILITY OF PALLADIUM MEMBRANE FOR STEAM-REFORMING OF BIO-ETHANOL USING THE MEMBRANE REACTOR

Author(s):  
KOUJI KINOUCHI ◽  
MASAHIRO KATOH ◽  
TOSHIHIDE HORIKAWA ◽  
TAKUSHI YOSHIKAWA ◽  
MAMORU WADA

A Palladium membrane was prepared by electro-less plating method on porous stainless steel. The catalytic hydrogen production by steam-reforming of biomass-derived ethanol (bio-ethanol) using a Pd membrane was analyzed by comparing it with those for the reaction using reagent ethanol (the reference sample). And the hydrogen permeability of the palladium membrane was investigated using the same palladium membrane ( H 2/ He selectivity = 249, at ΔP = 0.10 MPa, 873 K). As a result, for bio-ethanol, deposited carbon had a negative influence on the hydrogen-permeability of the palladium membrane and hydrogen purity. The sulfur content in the bio-ethanol may have promoted carbon deposition. By using a palladium membrane, it was confirmed that H 2 yield (%) was increased. It can be attributed that methane was converted from ethanol and produced more hydrogen by steam reforming, due to the in situ removal of hydrogen from the reaction location.

2010 ◽  
Vol 24 (15n16) ◽  
pp. 2833-2837 ◽  
Author(s):  
MASAHIRO KATOH ◽  
KATSUNORI NISHIHARA ◽  
KOJI KINOUCHI ◽  
KOICHI CHOHAMA ◽  
TOSHIHIDE HORIKAWA ◽  
...  

Plating thin Palladium ( Pd ) film on the outer surface of a porous stainless steel tube enables very rapid hydrogen permeation with an absolute selectivity. Methane steam reforming for hydrogen production is performed in a Pd membrane reactor. In this reaction, carbon monoxide ( CO ) synthesized is known to affect hydrogen permeability. The effect on hydrogen permeability and the membrane stability were investigated. After hydrogen was flowed through Pd membrane for 1 hour, CO (1%, 10%, 100% diluted by helium) was flowed on the membrane for 1 hour, and hydrogen was re-permeated through the membrane. Under the all experiment, the temperature, the differential pressure and the flow rate of non-permeation side were 823K, 0.1 MPa and 10 ml·min-1, respectively. After the re-permeating hydrogen, the hydrogen permeation rate increased gradually. Finally the rate arrived at the constant value before CO was flowed. But the necessary time was depend on the concentration of CO . The necessary time for three concentration of CO 1%, 10%, and 100% were 30min, 60min, and 180min, respectively. The reason was that depositing carbon from CO affected to hydrogen permeability. The carbon was changed to methane by hydrogen flow and the membrane was recycled.


2011 ◽  
Vol 695 ◽  
pp. 25-28 ◽  
Author(s):  
Khanthima Hemra ◽  
Mettaya Kitiwan ◽  
Duangduen Atong

The palladium membranes were fabricated by mean of electroless plating method which provided thin and uniform film on a tubular alumina porous support. Subsequently, the annealing process which is one of the effective ways to enhance the permeability of membrane was performed in the temperature range of 600-800°C. The annealing temperature and time were found to have influence on membrane microstructure and its performance. Palladium annealed at 700°C for 8 hrs in nitrogen atmosphere had the highest hydrogen permeability and separation factor when operated at 600°C. The membrane morphologies observed by SEM showed that the sample treated at higher temperature had lower surface roughness. The annealed palladium composite membrane at 800°C revealed that some voids which occurred during electroless plating process were enlarged and caused the lower separation factor.


Catalysts ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 110
Author(s):  
Yuanqing Liu ◽  
Chau T. Q. Mai ◽  
Flora T. T. Ng

The glycerol hydrogenolysis to produce 1,2-propanediol without using externally supplied hydrogen was investigated using methanol present in crude glycerol to provide in situ hydrogen via its steam reforming reaction. This paper focuses on the promoting effect of Pd on the reactivity of a Cu/Zn/Al2O3 catalyst. Adding 2 wt% Pd onto a Cu/ZnO/Al2O3 catalyst significantly improved the selectivity to 1,2-propanediol from 63.0% to 82.4% and the glycerol conversion from 70.2% to 99.4%. This enhancement on the catalytic activity by Pd is mainly due to the improved hydrogenation of acetol, which is the intermediate formed during the glycerol dehydration. The rapid hydrogenation of acetol can shift the reaction equilibrium of glycerol dehydration forward resulting in a higher glycerol conversion. The improved reducibility of the catalyst by Pd allows the catalyst to be reduced in situ during the reaction preventing any loss of catalyst activity due to any potential oxidation of the catalyst. The catalyst was slightly deactivated when it was firstly recycled resulting in a 5.4% loss of glycerol conversion due to the aggregation of Cu and the deactivation became less noticeable upon further recycling.


Membranes ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 518
Author(s):  
Cecilia Mateos-Pedrero ◽  
Miguel A. Soria ◽  
Antonio Guerrero-Ruíz ◽  
Inmaculada Rodríguez-Ramos

The external surface of a commercial porous stainless steel (PSS) was modified by either oxidation in air at varying temperatures (600, 700, and 800 °C) or coating with different oxides (SiO2, Al2O3, and ZrO2). Among them, PSS-ZrO2 appears as the most suitable carrier for the synthesis of the Pd membrane. A composite Pd membrane supported on the PSS-ZrO2 substrate was prepared by the electroless plating deposition method. Supported Ru catalysts were first evaluated for the low-temperature methane dry reforming (DRM) reaction in a continuous flow reactor (CR). Ru/ZrO2-La2O3 catalyst was found to be active and stable, so it was used in a membrane reactor (MR), which enhances the methane conversions above the equilibrium values. The influence of adding H2O to the feed of DRM was investigated over a Ru/ZrO2-La2O3 catalyst in the MR. Activity results are compared with those measured in a CR. The addition of H2O into the feed favors other reactions such as Water-Gas Shift (RWGS) and Steam Reforming (SR), which occur together with DRM, resulting in a dramatic decrease of CO2 conversion and CO production, but a marked increase of H2 yield.


2014 ◽  
Vol 543-547 ◽  
pp. 3967-3973
Author(s):  
Bao Shan Han

There are abundant CBM (Coalbed Methane) in China. These CBM has caused a remarkable problem to the coal-mining in China. In order to improve the structure of Chinese energy and eliminate the risk of coal mine gas, the relevant industries and sections have implemented many explorations in CBM enriched areas. With great achievements, there are many important problems in the actions of CBM exploitation. The disadvantageous interaction of the surface CBM well and the later coal mining has been ignored at all. There are many disadvantages and defects. To solve these problems and eliminate or weaken the disadvantageous, the scientific and reasonable design of surface CBM well location is an important step. With the thinking of surface condition, coal mining plan, the arrangement of coal mine laneway, the direction and scale of the in-situ stress, and thinking more about the negative influence to and of surface CBM well, according to the theories of mining dynamics, mining engineering, mining geomechanics, and the CBM engineering, the design theory of the surface CBM well net can be studied. Finally, the arrangement principle of CBM product well in coal field is presented. The existing or future coal pillar will be a critical location for the surface CBM well location.


2011 ◽  
Vol 179-180 ◽  
pp. 1309-1313 ◽  
Author(s):  
Xiao Liang Zhang ◽  
Xu Feng Xie ◽  
Yan Huang

Pd-based composite membranes are the attractive membrane materials for hydrogen separation due to their high hydrogen permeability and infinite permselectivity. Thin pure Ni and Pd-Ni alloy membranes with high hydrogen permeation were prepared by the electroless plating method. It is difficult to prepare the dense pure Ni membranes with 1-2 μm thickness for hydrogen separation. However, Pd-Ni alloy membranes with several micrometers thickness showed good permeation performance. Hydrogen permeance of the Pd95Ni5 alloy membrane with fcc phase up to 3.1×10-6 mol/m2 s Pa and the ideal permselectivity over 600 were obtained at 773 K.


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