Renewable Energy Global Innovations features: Water build-up and evolution during the start-up of a PEMFC: Visualization by means of Neutron Imaging

Significance Statement

The need to prolong the life of proton-exchange membrane fuel cell has of late accelerated. Researchers have realized that water management in the fuel cell has a major influence in the cell and stack performance. More so, it directly affects the durability of the cell components. Normally, the quantity of water generated at the cathode is directly proportional to the current density, therefore, the water removal capability of the cathode is a critical parameter for ensuring ultimate fuel cell performance.

Additionally, an appropriate water balance in the cell is crucial for durability purposes. Water evolution and build up during the start-up of proton-exchange membrane fuel cell is equally important, especially, since the relative humidity conditions around the electrodes are prone to variations. Therefore, to strike this balance, a technique that enables both the quantification and visualization of the local water content within the cell during operation, would be crucial. Besides, most of the two-phase flow studies found in literature center on the steady state behavior of water in the proton-exchange membrane fuel cell, whereas relatively few works address the transient behavior of the water build-up and evolution.

Alfredo Iranzo and colleagues proposed a study on water build-up and evolution during the start-up of a proton-exchange membrane fuel cell: Visualization by means of Neutron Imaging – a technique that allows visualization and quantification of local water content in the cell during operation simultaneously. Their main objective was to further look into the water build up and evolution during the start-up the cell, for a set of different anode and cathode relative humidity conditions. Their research work is published in International Journal of Hydrogen Energy.
Briefly, the empirical procedure involved operating a commercial 50 cm2 proton-exchange membrane fuel cell with serpentine flow fields at 2.0 bars and 60 C with varying relative humidity values for the inlet reactants. Between each tests, the team ensured that the cell was decompressed and the liquid water was thus flushed out. They then utilized Neutron Imaging to record the liquid water build up and the time evolution during each experiment. Eventually, they conducted a qualitative and quantitative analysis using the recorded data.

The research team mainly observed that the dynamics of the water build up comprises of three main stages, where the main difference is the local liquid water accumulation rate. They noted that the onset location for the water appearance in the flow field channels was determined by the flow field design, gravity and gas flow direction along the serpentine path. Eventually, they analyzed the time evolution of the water progressive accumulation along the flow field channels and cell active area.

Herein, a comprehensive experimental investigation of channel liquid water distributions in a 50 cm2 Proton-exchange membrane fuel cell with serpentine flow field has been presented. Neutron radiographs have been used to determine water build-up and time evolution of the liquid water content and distributions for a set of several varying operating conditions of the cell. The outcomes of this study are impressive and provide crucial insight into the liquid water dynamics during cell transients that can contribute to a better understanding and optimized design of cell components and operating conditions, which should result in an optimized performance of the cell dynamics in applications such as automotive fuel cells dealing with driving cycles.

About The Author

Alfredo Iranzo obtained a Masters Degree in Chemical Engineering at the University of Zaragoza, Spain, in 2000. After five years working in the Fluids Business Unit at ANSYS Germany in Otterfing (Munich, Germany), he obtained a Master of Science in Thermal Energy Systems at the University of Seville, Spain, in 2010, and a PhD degree in 2011 with a research work on CFD PEM Fuel Cell modelling and experimental validation. His current research interests include PEM Fuel Cell modelling and experimental techniques, solar hydrogen production and other CFD activities in Chemical and Energy Engineering.

Alfredo Iranzo is author of over 25 publications in JCR international peer-reviewed scientific journals and two book chapters. He is member of the Editorial Board of two JCR international peer-reviewed scientific journals: “International Journal of Hydrogen Energy” and “Engineering Applications of Computational Fluid Mechanics”. He has been included in “Who´s who in Science and Engineering”, Ed. Marquis, in the 2012th and 2015/16th editions.

Reference

Alfredo Iranzo, Antonio Salva, Pierre Boillat, Johannes Biesdorf, Elvira Tapia, Felipe Rosa. Water build-up and evolution during the start-up of a PEMFC: Visualization by means of Neutron Imaging. International journal of hydrogen energy volume 42 (2017) pages 13839-13849.

 

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Renewable Energy Global Innovations features: Reactor core transient analysis of innovative high-level nuclear waste transmuter with metal fuel

Significance Statement

Nuclear energy presents a sustainable energy supply and cheap electricity. It has been indicated to minimize the emission of greenhouse gases. Unfortunately, nuclear energy also has some shortcomings in sustainability. One important issue on this emanates from the disposal of spent fuels discharged from the reactors. Therefore, transmutation and partitioning of the minor actinides in the spent fuels will be necessary for the self-sustainment of the nuclear industry.
The radiotoxic inventory of the geological repositories will be reduced up to a factor of 100 if minor actinides and plutonium will be completely transmuted and recycled. Researchers have indeed investigated extensively with varying fuel cycle strategies, reactor systems and neutron spectrums. Fast reactors have been identified as the most promising candidates.
Unfortunately, transmuting minor actinides in fast reactors have been found to have significat safety concerns on the performance of the reactor cores. It has been demonstrated that the high amount of minor actinides such as neptunium and americium, initiates severe deterioration of coolant density reactivity feedback in the heavy-liquid-metal-cooled fast reactors. Researchers have found that it is important to reduce the core power by about 4% for every 1% addition of americium loaded in a lead-cooled fast reactor. If minor actinides are added in a reactor core, its neutronic safety performance becomes worse.
Since the economy of a nuclear reactor is dictated by the operational power level, it is uneconomical to undertake minor actinides transmutation in a critical fast reactor, which must be operated in a reduced power level in a bid to maintain sufficient safety margin. Fortunately, the accelerator driven subcritical system has a larger safety margin in minor actinides transmutation as opposed to the critical fast reactors.
In view of the fact that transmutation in the current operational reactors is insufficient and poses some safety concerns, Professor Youqi Zheng and colleagues from Xian Jiaotong University, China, proposed an accelerator-driven subcritical transmuter, which was named highly efficient industrial transmuter (HEIT) in a move to address these concerns. Their research work is published in International Journal of Energy Research.
The proposed system utilizes uranium-free metallic dispersion fuel and has high power density. The authors focused on the transient analysis of the highly efficient industrial transmuter in order to stablish its feasibility in the future nuclear applications. They analyzed cladding stresses, cumulative creep damage fractions and temperatures. In addition, the researchers investigated the burnup dependence and evaluated three transients: the beam overpower, the unprotected transient overpower, and the unprotected loss of flow.
The authors observed that the highly efficient industrial transmuter core remained safe without scram in a majority of transient cases. From the results, there was indicated that there will be enough safety margins from fuel pin failure. In the unprotected loss of flow transient, the cladding cloud exceeded the rapture limit in approximately half an hour when no shutdown responded. This was reference to the positive coolant density coefficient caused by the minor actinides loading.
The creep damage fraction as well as the maximum temperature was observed to change with the depletion owing to the delay heat fraction and power distribution variation. For the unprotected loss of flow transient, the end of lifetime was bounding, while for the case of beam overpower and unprotected transient overpower transients, both the end of lifetime and the beginning of lifetime ought to have been accommodated.

About The Author

Youqi Zheng
Associate Professor
School of Nuclear Science and Technology
Xi’an Jiaotong University
Xi’an, Shaanxi 710049, China
Tel: +86-29-82668692 Fax: +86-29-82668916
Email: yqzheng@mail.xjtu.edu.cn

Education:

Ph.D, Nuclear Science and Technology, Xi’an Jiaotong University, 2011
B.D, Nuclear Engineering and Technology, Xi’an Jiaotong University, 2006

Experience:

Jan. 2014- …, Associate Professor, School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an, China.
 July. 2015- July. 2016, Post-doctoral researcher, Ulsan Institute of Science and Technology, Ulsan, Korea.
Apr. 2011- Dec. 2013, Lecturer, School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an, China.

Research Fields:

Reactor physics; Advanced nuclear reactor R&D; High-level nuclear waste transmutation; Computational method for reactor core analysis

Awards:

First Class Prizes of Shaanxi Technical Invention Award, 2017
Third Class Prizes of China National Nuclear Corporation Scientific and Technological Progress Award, 2017
Young Talent Supporting Project of Chinese Association for Science and Technology, 2015
Outstanding Doctoral Dissertation Award in Shannxi Province, 2013

Selected Publications:

1. Youqi Zheng^*, Xunzhao Li, Hongchun Wu, Effect of high-energy neutron source on predicting the proton beam current in the ads design, Nuclear Engineering and Technology, in press, http://ift.tt/2l58pXh.
2. Youqi Zheng, Sooyoung Choi, Deokjung Lee. A new approach to three-dimensional neutron transport solution based on the method of characteristics and linear axial approximation, Journal of Computational Physics, 111: 271-279, 2018.
3. Youqi Zheng, Deokjung Lee, Peng Zhang, et al. Comparisons of S-N and Monte-Carlo methods in PWR ex-core detector response simulation, Annals of Nuclear Energy, 101: 139-150, 2017.
4. Youqi Zheng^*, Yunlong Xiao, Hongchun Wu, Application of the virtual density theory in fast reactor analysis based on the neutron transport calculation, Nuclear Engineering and Design, 320: 200–206, 2017.
5. Youqi Zheng^*, Mingtao He, Liangzhi Cao, et al., Reactor core transient analysis of an innovative high-level nuclear waste transmuter with metal fuel, International Journal of Energy Research, 41(9): 1322-1334, 2017.
6. Mingtao He, Youqi Zheng^*, Hongchun Wu, et al. Assessment of transient characteristics of fast reactors and influences of minor actinides using neutron transport method, International Journal of Energy Research, 41(14): 2194-2205, 2017.
7.  Mingtao He, Hongchun Wu, Youqi Zheng^*, et al. Beam transient analyses of Accelerator Driven Subcritical Reactors based on neutron transport method, Nuclear Engineering and Design, 295: 489–499, 2015.
8. Xunzhao Li, Shengcheng Zhou, Youqi Zheng^*, et al. Preliminary studies of a new accelerator-driven minor actinide burner in industrial scale, Nuclear Engineering and Design 292: 57–68, 2015.
9. Yunlong Xiao, Hongchun Wu, Youqi Zheng^*, et al. Neutronics studies on the feasibility of developing fast breeder reactor with flexible breeding ratio. Journal of Nuclear Science and Technology, 53(1): 129-138, 2015.
10.  Youqi Zheng, Hongchun Wu, Liangzhi Cao, et al. Daubechies’ Wavelet Method for Angular Solution of the Neutron Transport Equation. Nuclear Science and Engineering, 164(2): 87-104, 2010.

Reference

Youqi Zheng, Mingtao He, Liangzhi Cao, Hongchun Wu, Xunzhao Li and Shengcheng Zhou. Reactor core transient analysis of an innovative high-level nuclear waste transmuter with metal fuel. International Journal of Energy Research, volume 41 (2017), pages 1322–1334.

 

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Renewable Energy Global Innovations features: Improved solar light stimulated charge separation of g-C3N4 through self-altering acidic treatment

Significance Statement

The process of identifying more efficient as well as green photocatalysts for several environmental remediation and energy conversion processes have received global attention in the last few years. The transformation of the renowned semiconductor catalysts, titanium oxide to the recently synthesized metal free semiconductor, graphitic carbon nitride had exhibited great progress. Recently, this photocatalyst has received significant research attention owing to its distinctive features such as anti-photo corrosion, chemically stable, low cost, and contains most abundant elements. Unfortunately, graphitic carbon nitride suffers from low surface area as well as high recombination rates leading to deprived photocatalytic efficacy.

A number of modifications have been done to enhance the underlying photocatalysis of the bulk graphitic carbon nitride, which include doping with non-metal/metal and other semiconductors and copolymerization.  In addition to enhance the synthesis of new green synthesis photocatalysts, researchers should reconsider on doping modification method. Self-modification of the graphitic carbon nitride is a modification process that has neither been least nor not considered. Recently, graphitic carbon nitride with alkali treatment has developed exhibiting considerable improvement in extending the longevity of the electron hole pairs excited under visible light irradiation. The enhancement in photocatalysis was developed by the decomposing RhB dye.

In addition, porous graphitic carbon nitride with several acidic templates that indicate high performance on degenerating Rhodamine B and phenol has been modified. Unfortunately, this self-altering method of graphitic carbon nitride refinement for solar photocatalysis has not been attempted. Professor Kah Hon Leong and colleagues implemented acid treatment to treat graphitic carbon nitride nanostructured by a direct synthesis method. The proposed treatment enhanced photoactivity of graphitic nitride and was reflected in the removal of recalcitrant organic pollutant, under direct sunlight. Their research work is published in peer-reviewed journal, Applied Surface Science.

The authors prepared photocatalysts that were analyzed via a sustainable photocatalysis method using sunlight as a source of radiation and selecting a poor photosensitive pollutant compound, Bisphenol A. They conducted the experiments under a bright and intense sunlight. In addition, the authors performed dark experiments for about 3 hours to realize adsorption and desorption equilibrium. These experiments were done before solar photocatalysis experiment. Moreover, a control experiment was done in the absence of a photocatalyst.

The authors were able to prepare self-alteration to bulk graphitic carbon nitride via an elementary and direct preparation path with acidic treatment in a bid to extend the longevity of its charge carriers. The researchers recorded a complete removal of the Bisphenol A in 225 minutes by the treated graphitic carbon nitride under intense sunlight as compared to pure graphitic carbon nitride. The improvement could be referenced to the blue shift and delayed the rate of recombination of electrons and holes.

In addition, it influenced the development of active superoxide anion radicals, which were responsible for the photocatalytic activity. The authors then proposed a mechanism of electrons flow that would play a critical role in identifying self-enhancement photocatalysts, which would be stable under intense solar energy.

The outcomes of their study would be important for the increased demand for solar light sensitive photocatalysts that are necessary in satisfying the demands of complicated environmental pollutants particularly in enhancing a sustainable environment.

About The Author

Dr Kah Hon Leong received his Ph.D in Environmental Engineering from University of Malaya in 2015. Currently, he is an Assistant Professor at Universiti Tunku Abdul Rahman, Malaysia. His research focuses on design and synthesis of highly improved solar light driven nanomaterials for sustainable environmental and energy applications.

About The Author

Mr.Ping Feng Lim studied Environmental Engineering from Universiti Tunku Abdul Rahman, Malaysia and graduated in 2016. Currently, he is doing his master degree with Dr Kah Hon Leong on the subject of perovskite photocatalysts for sustainable environmental remediation.

About The Author

Dr. Lan Ching Sim received her Ph.D in Environmental Engineering from University of Malaya in 2015. Currently, she is an Assistant Professor at Universiti Tunku Abdul Rahman. Her research interests include the developing and synthesis of semiconductor, plasmonic and carbon materials photocatalysts for water and energy applications.

About The Author

Mr.Varun Punia is pursuing Bachelor of Technology in Civil Engineering at Indian Institute of Technology Roorkee, India. He has worked at the Environmental Nanotechnology Research Laboratory, Department of Civil Engineering, University of Malaya, Malaysia during his summer internship visit in 2016.

About The Author

Dr. Pichiah Saravanan received doctoral degree in Chemical Engineering from Indian Institute of Technology Guwahati, India. Presently he is Associate Professor in Department of Environmental Science and Engineering, Indian Institute of Technology (ISM) Dhanbad, India and also heading the Environmental Nanotechnology research laboratory.

He was key founder of “Environmental Nanotechnology” research laboratory at Department of Civil Engineering, University of Malaya, Malaysia where he served as Senior Lecturer between 2010 to 2016. He is fascinated in developing nanomaterials for sustainable environmental remediation’s and energy applications.

Reference

Kah Hon Leong, Ping Feng Lim, Lan Ching Sim, Varun Punia, Saravanan Pichiah. Improved solar light stimulated charge separation of g-C₃N₄ through self-altering acidic treatment. Applied Surface Science

 

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Renewable Energy Global Innovations features: Relevant efficiency enhancement of emerging Cu2MnSnS4 thin film solar cells by low temperature annealing

Significance Statement

In the recent years, thin film solar cell manufacturers have suffered from the abrupt decrease of silicon module price. Irrespective of the current efficiency of Cu(In, Ga) Se2 thin film solar cells being very near to the already established silicon-based photovoltaic technology, the low availability of gallium and indium in the Earth’s crust will result in their high cost, and this will definitely limit their future role in terawatt range photovoltaic applications. Therefore, researchers have shifted their attention to low cost materials based on earth abundant elements.

Fortunately, there is an attractive alternative for the preparation of indium and gallium free terawatt-scale chalcogenides. These alternatives depend on I₂-II-IV-VI₄ species, which include copper zin tin sulfide, copper zinc tin selenide and the related sulphur-selenium alloy. Copper manganese tin sulfide, a p-type semiconductor based fully on earth abundant as well as low cost elements, is another member of this group of materials . In view of the fact that manganese is cheaper than zinc, copper manganese tin sulfide can provide W_p cost lower as compared to copper zinc tin sulfide.

Copper manganese tin sulfide that crystalizes into a stannite structure exhibits direct band gap and high absorption coefficient all of which are necessary for photovoltaic applications. Several studies on copper manganese tin sulfide have been mainly based on single crystals and nanocrystals. However, recent studies have been reported on copper manganese tin sulfide thin films for photovoltaic applications.

Alessia Le Donne, Maurizio Acciarri and Simona Binetti at University of Milano-Bicocca in collaboration with Stefano Marchionna and Federico Cernuschi at RSE SpA grew copper manganese tin sulfide thin films through a two-step vacuum process. They grew metal precursor stacks through thermal evaporation and then heat treated them in elemental sulfur vapors. Their research work is published in Solar Energy.

The authors settled for Cu-poor/Mn-rich copper manganese tin sulfide films with Mn/Sn ratio of 1 in a bid to avoid the development of insulating and highly conductive secondary phases. The researchers tested the proposed copper manganese tin sulfide thin films by photoluminescence, Raman, Scanning Electron Microscopy and Energy Dispersive Spectroscopy.

The research team were able to obtain Cu-poor/Mn-rich copper manganese tin sulfide specimens with an acceptable homogeneity of the metal compositional ratios through a stringent control of the manganese evaporation rate. Solar cells manufactured from the films indicated good performance as opposed to a previous study. In view of the advantages of low temperature post-deposition annealing in inert and air atmosphere reported in the literature, the authors investigated the impact of thermal treatments they did between 200 and 275 °C on the copper manganese tin sulfide solar cell efficiency. The analysis encompassed both modification of material attributes and electrical performance.

The best annealing at 225 °C in air for about 40 minutes allowed for significant enhancement of their performance, open circuit voltage 354 mV, short circuit current density 5.8 mA/cm2, 40% fill factor and efficiency of 0.83%. This therefore increased the efficiency of this promising material.

About The Author

Alessia Le Donne got a M.S. degree in Materials Science from the University of Milano-Bicocca in 2001 and in 2004 a Ph.D. in Materials Science from the same Institution. Since 2005 she got several postdoctoral fellowships at the University of Milano-Bicocca and a research fellowship at CNISM (National Interuniversity Consortium for the Physical Sciences of Matter).

She co-authored 63 peer-reviewed papers, 1 book chapter and more than 80 contributions at national or international scientific conferences. Since 2001 she has been involved in several European and national Projects. She regularly serves as peer-reviewer for high impact factor international scientific journals. She is associated editor of the international journals ‘Reviews in Advanced Sciences and Engineering’ and ‘Materials Focus’ and member of the editorial board of ‘Conference Papers in Energy’ and ‘Indian Journal of Materials Science’.

About The Author

Stefano Marchionna got a M.S. degree with honours in Materials Science from the University of Milano-Bicocca in 2003 and a Ph.D. in Materials Science from the same University in 2006. He co-authored 20 peer-reviewed papers and more than 30 communications at national or international scientific conferences. In 2007, he was process engineer at NED Silicon Company (Italy), working on the development of an innovative production line for solar grade silicon. From 2008 to 2013, he was process engineer at Voltasolar Company (Italy), working on the development of low-cost thin films solar cells based on Cu(In,Ga)Se₂ (CIGS). Presently, his research activity at RSE SpA (Italy) is focused on the development of new and alternative materials based on Earth abundant elements both for photovoltaic and energy storage applications.

About The Author

Maurizio Acciarri is Associate Professor in Physics at the Department of Materials Science of the University of Milano-Bicocca. His research activity is mainly addressed to the study of electrical properties of semiconductors for photovoltaic applications. His research in the field of thin films for photovoltaic applications led to an international patent and to the technological transfer of the related Cu(In, Ga)Se₂ growth process to a pilot line. He is co-author of 4 patents. From 2017 he is Director of the Management Committee of the Microscopy Platform of the University of Milano-Bicocca.

Since 2011 he is member of the scientific committee of the Milano-Bicocca Solar Energy Research Center (MIBSOLAR) and since 2013 he is co-director of the center. Since 2014 he is member of the scientific committee and teacher of the Green Energy Management Summer School. Since 2017 he is member of the scientific committee and teacher for the PhD school in Sustainable Human Development. Since 2017 he is member of the editorial board of the international journal ‛Solar Energy’.

About The Author

Federico Cernuschi is the head of the Materials for Energy Research Group at RSE SpA. After completing his studies in physics at the University of Milan, since 1990 he worked on the development and application of advanced non-destructive techniques for the integrity assessment of power plant components and for the physical, thermophysical characterization and wear resistance of coatings and materials for energy applications. He has been responsible for several EU funded research projects. He has published more than 60 papers in international scientific journals. He sits on national and international standards committees focusing on wear and NDE&T and advanced ceramics.

About The Author

Simona Binetti is Associated Professor of Physical Chemistry at University of Milano-Bicocca,  vice director of Milano-Bicocca Solar Energy Research Center (MIBSOLAR), representing UNIMIB in the Joint Program on Photovoltaics of European Energy Research Alliance. Qualified Full Professor in Physical Chemistry. Graduated in Physics, Master in Materials Science and PhD in Chemistry.

Recognized expert in effect of defects on optoelectronic properties of silicon based semiconductors. Involved in 10 European Projects, 9 national about PV, some of them as leader, collaborating in research for private owned companies. She is currently leading 3 projects. Co-author of 120 peer-reviewed publications, 4 book chapters, 4 patents.

Reference

A. Le Donne, S. Marchionna, M. Acciarri, F. Cernuschi, S. Binetti. Relevant efficiency enhancement of emerging Cu₂MnSnS₄ thin film solar cells by low temperature annealing. Solar Energy, volume 149 (2017), pages 125–131.

 

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Renewable Energy Global Innovations features: MnO-Co Composite Modified Ni-SDC Anode for Intermediate Temperature Solid Oxide Fuel Cells

Significance Statement

Fuel cells have the ability to convert chemical energy in fuels to electric energy without the inhibition of the Carnot cycle. Conventional power generating devices are deficient in efficiency, low emissions and the potential for combined heat and power generation, critical features among which the fuel cell vehemently manifests. Solid oxide fuel cells (SOFCs) often operate at high temperatures which contributes to a higher efficiency and power density as compared to other types of fuel cells. More so, the high operating temperatures enable the SOFCs to utilize carbon monoxide as a fuel rather than a poison. SOFCs with Ni-YSZ (yttria-stabilized zirconia) cermet anodes often operate at a higher temperature which translates into higher synthesis cost. Conversely, SOFCs with Ni-SDC (samarium-doped ceria) cermet anodes have exhibited lower operating temperatures and excellent electrochemical performance at intermediate temperatures. Besides, efforts are still needed so as to promote the performance and stability of SOFCs of Ni-SDC anodes in hydrogen and/or methane.

Zhonghua Zhu and his group at The University of Queensland in Australia, proposed studies to enhance the electrochemical performance and/or stability of Ni-SDC anode in hydrogen and/or methane. The authors firstly modified the Ni-SDC anode with manganese oxide and cobalt (MnO-Co) composite in a bid to further promote its performance. The research team begun their empirical work by ball-milling NiO, SDC, dextrin (pore former) and synthesized manganese-cobalt spinel in ethanol for a specific period. They then prepared the anode-supported solid oxide fuel cells. The crystal structures of the synthesized powders and anode powders were characterized by x-ray diffraction. The microstructure of the fabricated solid oxide fuel cells was also examined by scanning electron microscopy.

After the successful fabrication of the Ni-SDC and MnO-Co composite modified Ni-SDC anode-supported SOFCs, the authors observed that when compared with the normal Ni-SDC anodes, the MnO-Co modified Ni-SDC anodes exhibited much higher peak power density and lower polarization resistance in dry hydrogen gas and dry methane gas at all of the temperatures investigated. The modified anode had higher porosity than the original anode. However, the team noted that the stability of MnO-Co modified Ni-SDC anodes was worse than that of Ni-SDC anodes in dry methane due to severer carbon deposition. This research work is now published in Fuel Processing Technology.¹ After that, the authors applied a MnO-Co-SDC internal reforming layer over the Ni-SDC anode and observed significant improvement in its performance and stability in wet methane (3mol% H₂O in methane). They found that the anode started to decline in 150 minutes without the reforming layer, but showed no indication of degradation over 900 minutes due to the methane pre-reforming process after the addition of the MnO-Co-SDC layer at 0.2A/cm² and 650 ^oC and the peak power density was further increased by over 10%. This work has been published in Journal of Materials Chemistry A.² On-going research is being carried out in Prof Zhu’s group.

Reference

• Jie Zhao, Xiaoyong Xu, Wei Zhou, Zhonghua Zhu. MnO-Co composite modified Ni-SDC anode for intermediate temperature solid oxide fuel cells. Fuel Processing Technology, volume 161 (2017) pages 241–247.

Go To Fuel Processing Technology 

 

• Jie Zhao, Xiaoyong Xu, Wei Zhou, Zhonghua Zhu. An in situ formed MnO–Co composite catalyst layer over Ni–Ce₈Sm_0.2O_2-x anodes for direct methane solid oxide fuel cells. Journal of Materials Chemistry A, volume 5 (2017) pages 6494-6503.

 

Go To Journal of Materials Chemistry A  

 

 

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Renewable Energy Global Innovations features: Room temperature hydrogen production from Hg contaminated water, with desirable throughput, and simultaneous Hg-removal

Significance Statement

Fossil fuels produce toxic byproducts on oxidation; hydrogen on the other hand yields water vapor making it a better source of energy. Today industrial hydrogen production primarily adopts an approach using steam reforming of fossil fuels. However carbon monoxide and carbon dioxide are emitted as byproducts of this process. Given this an obvious and simple way of getting hydrogen would be by splitting water, since it is abundant globally. Researchers world over are attempting development of hydrolytic reagents that result in high throughput hydrogen production through splitting of water (also called hydrolysis).

Currently there are numerous methods used for generating hydrogen which include: water decomposition at high temperature, photo electrochemical water splitting, decomposition of water electrochemically, and metal hydrolysis. Heat and electrochemical based water splitting approaches tend to be energy intensive. Light based approaches (i.e photo electrochemical or photochemical) tends to require very pure water, is usually low efficiency, and not yet robust as a process. Metal hydrolysis tends to be expensive and if carefully looked at, is high on carbon footprint (since metal extraction is energy intensive too).

Furthermore post production of hydrogen, its storage, transportation, and handling presents many safety issues. Hence hydrogen fuel though seemingly ideal, is fraught with many engineering challenges. Consequently, there is need to improve techniques of production. It would be ideal to have a process that generates hydrogen on demand; better still if this could be done using dirty water!  Abdul Malek, Edamana Prasad, Subrahmanyam Aryasomayajula, and Tiju Thomas at the Indian Institute of Technology Madras (IITM) in India have developed an approach that does just that. The approach uses nanoscience based ideas to achieve this engineering outcome. – The team developed a novel method with high hydrogen production efficiency using water contaminated with mercury (usually an issue in effluents from several industries, including mines, leather industries etc). The researchers aimed at generating hydrogen through ‘in situ’ formation of nanoaluminum amalgam by simultaneously reducing aluminum (obtained from inexpensive salts) and mercury (present as a contaminant) using a powerful reducing agent. The research work is now published in the journal, International Journal of Hydrogen Energy.

The experiment works well with tap water and would do just as well with dirty water contaminated with mercury. The process cleans up mercury from water, while at the same time producing hydrogen. The process works since the nano-alloy they synthesize using this in situ approach has many galvanic couples on its surface (think of them as ‘nano batteries’ sitting on the nanoparticle surface). In the lab scale,  researchers observed rampant production of hydrogen gas (720 mL per minute of hydrogen for every 0.5 mg of Al salt used). The presence of other contaminants (eg. salts) did not seem to affect the rate nor the amount of hydrogen gas produced. The process scales rather easily with the amount of aluminium salt used; this makes it in principle useful for point of use production of hydrogen (providing a plausible way out for the transportation and storage problem).

Scaling up in the next step, and the team is excited to further their work towards this end. Dr. Tiju Thomas, one of the senior authors said “Getting fuel while purifying water is a very good example of how design thinking and nanoscience can solve some major problems. I particularly enjoy doing this. We, as a team, are excited about the possibility of using this technology is parts of the world wherein mercury is a major contaminant in water. The team behind this story believes that we have just gotten the right lead. Scaling up is the way to go, and partnering with process, water and energy engineers in industry is essential to take this technology to the real world. We have made a good start – the science is there; the next step is to make it available to change makers and innovate along with them”.

In conclusion, Abdul Malek and his co-workers have shown a possible way to overcome some of the major setbacks in current water and hydrogen energy sectors. It offers a possibility for scale up, and improve the efficiency of generating hydrogen using dirty water (mercury contaminated as of now). This method also helps to address the problem of storage and transportation of material, while also cleaning up the mercury from water. The technology lends itself to point of use hydrogen production; the challenges that remains are at the device and systems level. The team envisions their invention to give way to a multi-functional technology.  This procedure is possibly applicable to ocean water and effluents from industries with more complex contaminant composition because of the inability of salts to affect the process. Therefore, more work along these lines are anticipated, and hence development of suitable devices and reactors are the way to go. Everything herein suggests that this novel technique is viable and suitable for adoption. It is important to note here that the technique developed by Abdul Malek and his co-workers is patented (PCT/ IN2017/ 050334) and available for licensing. They are also happy to discuss industry relevant and academic questions with their professional colleagues world over.

Reference

Abdul Malek, Edamana Prasad, Subrahmanyam Aryasomayajula, Tiju Thomas. Chimie douce hydrogen production from Hg contaminated water, with desirable throughput, and simultaneous Hg-removal. International Journal of Hydrogen Energy, Volume 42 (2017) page 15724-15730.

 

Go To International Journal of Hydrogen Energy

 

Malek, A.; Thomas, T.; Prasad, E. Hydrogen generation from waste water via galvanic corrosion of in-situ formed aluminum amalgam, Indian Patent Office, Application No. 201641027502; International application no: PCT/ IN2017/ 050334.

A. Malek, T. Thomas, E. Prasad, Visual and optical sensing of Hg²⁺, Cd²⁺, Cu²⁺, and Pb²⁺ in water and its beneficiation via gettering in nanoamalgam form. ACS Sustain Chem Eng, 4 (2016), pp. 3497-3503.

 

 

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