Phase Separation Characteristics of Pressurized Bunsen Reaction for Sulfur-Iodine Thermochemical Hydrogen Production Process

2012 ◽  
Vol 550-553 ◽  
pp. 554-557 ◽  
Author(s):  
Young Ho Kim ◽  
Hyo Sub Kim ◽  
Sang Jin Han ◽  
Chu Sik Park ◽  
Ki Kwang Bae ◽  
...  
Keyword(s):  
Phase Separation ◽  
Hydrogen Production ◽  
Production Process ◽  
Flow Reactor ◽  
Continuous Operation ◽  
Side Reactions ◽  
Steady State Operation ◽  
Production Of Hydrogen ◽  
Continuous Reaction ◽  
Counter Current

The Sulfur-Iodine (SI) thermochemical hydrogen production process is promising method for the massive production of hydrogen using the high temperature thermal energy of VHTR. For continuous operation of SI process, the conditions of Bunsen reaction are considered as the pressurized conditions with ca. 373~393K temperature and the composition of Bunsen products should be kept constant during the reaction. Therefore, we carried out the continuous Bunsen reaction using a counter-current flow reactor at pressurized condition to investigate the phase separation characteristics of pressurized Bunsen reaction. As the results, the composition of Bunsen product was maintained constantly as the evidence for the steady-state operation. The continuous reaction was operated without occurrence of side reactions, and a H2SO4 phase and HIx phase as the product contains a small amount of impurities (HI in a H2SO4 phase and H2SO4 in a HIx phase). We concluded that the pressurized Bunsen reaction is favorable to the continuous operation of SI process than the atmospheric reaction.

Bunsen Reaction Using a Counter-Current Flow Reactor in Sulfur-Iodine Hydrogen Production Process: Effects of Reactor Shape and Temperature

2011 ◽  
Vol 347-353 ◽  
pp. 3238-3241
Author(s):  
Young Ho Kim ◽  
Hyo Sub Kim ◽  
Sang Jin Han ◽  
Chu Sik Park ◽  
Ki Kwang Bae ◽  
...  
Keyword(s):  
Phase Separation ◽  
Hydrogen Production ◽  
Water Splitting ◽  
Current Flow ◽  
Flow Reactor ◽  
Heat Energy ◽  
Continuous Operation ◽  
Storage Tanks ◽  
Process Effects ◽  
Counter Current

The sulfur-iodine (SI) cycle, thermochemical water splitting using heat energy from nuclear, is one of the most promising methods for massive hydrogen production. For continuous operation of Bunsen reaction section in SI process, the reactants (SO2, I2 and H2O) were fed to the reactor and the products (a H2SO4 phase and a HIx phase) were sent to storage tanks continuously during the reaction. In this study, we investigated the phase separation characteristics of continuous Bunsen reaction on the reactor shape and temperature. It was found that the reactor shape has little affected on the composition of Bunsen products. It was also observed that the phase separation characteristics of the continuous Bunsen reaction were similar to those for the semi-batch Bunsen reaction.

Phase separation characteristics of the Bunsen reaction when using HIx solution (HI–I2–H2O) in the sulfur–iodine hydrogen production process

2014 ◽  
Vol 39 (2) ◽  
pp. 692-701 ◽  
Author(s):  
Hyo Sub Kim ◽  
Young Ho Kim ◽  
Byung Tae Ahn ◽  
Jong Gyu Lee ◽  
Chu Sik Park ◽  
...  
Keyword(s):  
Phase Separation ◽  
Hydrogen Production ◽  
Production Process

Characterization of a Polymeric Membrane for the Separation of Hydrogen in a Mixture with CO2

2016 ◽  
Vol 9 (1) ◽  
pp. 126-136 ◽  
Author(s):  
Dionisio H. Malagón-Romero ◽  
Alexander Ladino ◽  
Nataly Ortiz ◽  
Liliana P. Green
Keyword(s):  
Carbon Dioxide ◽  
Hydrogen Production ◽  
Test Performance ◽  
Low Cost ◽  
Time Lag ◽  
Polymeric Membrane ◽  
Biological Processes ◽  
Scanning Calorimetry ◽  
Environmentally Sustainable ◽  
Production Of Hydrogen

Hydrogen is expected to play an important role as a clean, reliable and renewable energy source. A key challenge is the production of hydrogen in an economically and environmentally sustainable way on an industrial scale. One promising method of hydrogen production is via biological processes using agricultural resources, where the hydrogen is found to be mixed with other gases, such as carbon dioxide. Thus, to separate hydrogen from the mixture, it is challenging to implement and evaluate a simple, low cost, reliable and efficient separation process. So, the aim of this work was to develop a polymeric membrane for hydrogen separation. The developed membranes were made of polysulfone via phase inversion by a controlled evaporation method with 5 wt % and 10 wt % of polysulfone resulting in thicknesses of 132 and 239 micrometers, respectively. Membrane characterization was performed using scanning electron microscopy (SEM), differential scanning calorimetry (DSC), atomic force microscopy (AFM), and ASTM D882 tensile test. Performance was characterized using a 23 factorial experiment using the time lag method, comparing the results with those from gas chromatography (GC). As a result, developed membranes exhibited dense microstructures, low values of RMS roughness, and glass transition temperatures of approximately 191.75 °C and 190.43 °C for the 5 wt % and 10 wt % membranes, respectively. Performance results for the given membranes showed a hydrogen selectivity of 8.20 for an evaluated gas mixture 54% hydrogen and 46% carbon dioxide. According to selectivity achieved, H2 separation from carbon dioxide is feasible with possibilities of scalability. These results are important for consolidating hydrogen production from biological processes.

scholarly journals Hydrogen production from water electrolysis: role of catalysts

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Shan Wang ◽  
Aolin Lu ◽  
Chuan-Jian Zhong
Keyword(s):  
Hydrogen Production ◽  
Water Splitting ◽  
Noble Metal ◽  
Active Sites ◽  
Current Knowledge ◽  
Low Cost ◽  
Critical Role ◽  
Water Electrolysis ◽  
Efficient Production ◽  
Production Of Hydrogen

AbstractAs a promising substitute for fossil fuels, hydrogen has emerged as a clean and renewable energy. A key challenge is the efficient production of hydrogen to meet the commercial-scale demand of hydrogen. Water splitting electrolysis is a promising pathway to achieve the efficient hydrogen production in terms of energy conversion and storage in which catalysis or electrocatalysis plays a critical role. The development of active, stable, and low-cost catalysts or electrocatalysts is an essential prerequisite for achieving the desired electrocatalytic hydrogen production from water splitting for practical use, which constitutes the central focus of this review. It will start with an introduction of the water splitting performance evaluation of various electrocatalysts in terms of activity, stability, and efficiency. This will be followed by outlining current knowledge on the two half-cell reactions, hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), in terms of reaction mechanisms in alkaline and acidic media. Recent advances in the design and preparation of nanostructured noble-metal and non-noble metal-based electrocatalysts will be discussed. New strategies and insights in exploring the synergistic structure, morphology, composition, and active sites of the nanostructured electrocatalysts for increasing the electrocatalytic activity and stability in HER and OER will be highlighted. Finally, future challenges and perspectives in the design of active and robust electrocatalysts for HER and OER towards efficient production of hydrogen from water splitting electrolysis will also be outlined.

scholarly journals A Process for Hydrogen Production from the Catalytic Decomposition of Formic Acid over Iridium—Palladium Nanoparticles

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3258
Author(s):  
Hamed M. Alshammari ◽  
Mohammad Hayal Alotaibi ◽  
Obaid F. Aldosari ◽  
Abdulellah S. Alsolami ◽  
Nuha A. Alotaibi ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Formic Acid ◽  
Activated Charcoal ◽  
Palladium Nanoparticles ◽  
Room Temperature ◽  
Catalytic Decomposition ◽  
Conversion Yield ◽  
Production Of Hydrogen ◽  
Commercial Applications

The present study investigates a process for the selective production of hydrogen from the catalytic decomposition of formic acid in the presence of iridium and iridium–palladium nanoparticles under various conditions. It was found that a loading of 1 wt.% of 2% palladium in the presence of 1% iridium over activated charcoal led to a 43% conversion of formic acid to hydrogen at room temperature after 4 h. Increasing the temperature to 60 °C led to further decomposition and an improvement in conversion yield to 63%. Dilution of formic acid from 0.5 to 0.2 M improved the decomposition, reaching conversion to 81%. The reported process could potentially be used in commercial applications.

scholarly journals Iridium Complex Catalyzed Hydrogen Production from Glucose and Various Monosaccharides

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 891
Author(s):  
Ken-ichi Fujita ◽  
Takayoshi Inoue ◽  
Toshiki Tanaka ◽  
Jaeyoung Jeong ◽  
Shohichi Furukawa ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Catalytic System ◽  
Catalytic Reaction ◽  
Hydrogen Gas ◽  
Water Soluble ◽  
Starting Material ◽  
Iridium Complex ◽  
Production Of Hydrogen ◽  
Bipyridine Ligand

A new catalytic system has been developed for hydrogen production from various monosaccharides, mainly glucose, as a starting material under reflux conditions in water in the presence of a water-soluble dicationic iridium complex bearing a functional bipyridine ligand. For example, the reaction of D-glucose in water under reflux for 20 h in the presence of [Cp*Ir(6,6′-dihydroxy-2,2′-bipyridine)(H2O)][OTf]2 (1.0 mol %) (Cp*: pentamethylcyclopentadienyl, OTf: trifluoromethanesulfonate) resulted in the production of hydrogen gas in 95% yield. In the present catalytic reaction, it was experimentally suggested that dehydrogenation of the alcoholic moiety at 1-position of glucose proceeded.

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