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 ◽  
...  

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.

2012 ◽  
Vol 550-553 ◽  
pp. 554-557 ◽  
Author(s):  
Young Ho Kim ◽  
Hyo Sub Kim ◽  
Sang Jin Han ◽  
Chu Sik Park ◽  
Ki Kwang Bae ◽  
...  

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.


2020 ◽  
Vol 16 ◽  
Author(s):  
Yuxue Wei ◽  
Honglin Qin ◽  
Jinxin Deng ◽  
Xiaomeng Cheng ◽  
Mengdie Cai ◽  
...  

Introduction: Solar-driven photocatalytic hydrogen production from water splitting is one of the most promising solutions to satisfy the increasing demands of a rapidly developing society. CdS has emerged as a representative semiconductor photocatalyst due to its suitable band gap and band position. However, the poor stability and rapid charge recombination of CdS restrict its application for hydrogen production. The strategy of using a cocatalyst is typically recognized as an effective approach for improving the activity, stability, and selectivity of photocatalysts. In this review, recent developments in CdS cocatalysts for hydrogen production from water splitting under visible-light irradiation are summarized. In particular, the factors affecting the photocatalytic performance and new cocatalyst design, as well as the general classification of cocatalysts, are discussed, which includes a single cocatalyst containing noble-metal cocatalysts, non-noble metals, metal-complex cocatalysts, metal-free cocatalysts, and multi-cocatalysts. Finally, future opportunities and challenges with respect to the optimization and theoretical design of cocatalysts toward the CdS photocatalytic hydrogen evolution are described. Background: Photocatalytic hydrogen evolution from water splitting using photocatalyst semiconductors is one of the most promising solutions to satisfy the increasing demands of a rapidly developing society. CdS has emerged as a representative semiconductor photocatalyst due to its suitable band gap and band position. However, the poor stability and rapid charge recombination of CdS restrict its application for hydrogen production. The strategy of using a cocatalyst is typically recognized as an effective approach for improving the activity, stability, and selectivity of photocatalysts. Methods: This review summarizes the recent developments in CdS cocatalysts for hydrogen production from water splitting under visible-light irradiation. Results: Recent developments in CdS cocatalysts for hydrogen production from water splitting under visible-light irradiation are summarized. The factors affecting the photocatalytic performance and new cocatalyst design, as well as the general classification of cocatalysts, are discussed, which includes a single cocatalyst containing noble-metal cocatalysts, non-noble metals, metal-complex cocatalysts, metal-free cocatalysts, and multi-cocatalysts. Finally, future opportunities and challenges with respect to the optimization and theoretical design of cocatalysts toward the CdS photocatalytic hydrogen evolution are described. Conclusion: The state-of-the-art CdS for producing hydrogen from photocatalytic water splitting under visible light is discussed. The future opportunities and challenges with respect to the optimization and theoretical design of cocatalysts toward the CdS photocatalytic hydrogen evolution are also described.


Nanoscale ◽  
2021 ◽  
Author(s):  
Dongxue Yao ◽  
Lingling Gu ◽  
Bin Zuo ◽  
Shuo Weng ◽  
Shengwei Deng ◽  
...  

The technology of electrolyzing water to prepare high-purity hydrogen is an important field in today's energy development. However, how to prepare efficient, stable, and inexpensive hydrogen production technology from electrolyzed...


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Shan Wang ◽  
Aolin Lu ◽  
Chuan-Jian Zhong

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.


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