2 reviews re HNi cold fusion, CE Stremmenos 2010: metal hydride
research: Rich Murray 2011.01.16 Advisers The Journal will publish papers, in the areas of interest, without charge. All papers will be reviewed by our scientific council to ensure scientific rigor and compliance with copyright law. Publications will not be corrected and will be published “as received” in chronological order of receipt. The authors are solely responsible for the contents of their papers. BOARD OF ADVISERS: Prof. Sergio Focardi (INFN – University of Bologna – Italy) Prof. Michael Melich (DOD – USA) Prof. Alberto Carnera (INFM – University of Padova – Italy) Prof. Giuseppe Levi (INFN – University of Bologna – Italy) Prof. Pierluca Rossi (University of Bologna – Italy) Prof. Luciana Malferrari (University of Bologna – Italy) Prof. George Kelly (University of New Hampshire – USA) Prof. Christos E. Stremmenos (Athen University – Greece) http://www.journal-of-nuclear-physics.com/?p=185 Evaluations, ideas and proposal upon new energy sources by Prof. Christos E. Stremmenos* BACKGROUND The hostile attitude which cold fusion has been confronted with since 1989, but even long before, shown also by the bibliography related to the scientific papers of Focardi and Rossi, eventually led to general disinterest and oblivion of this subject. After several years of apparent inaction, the theme of cold fusion has been recently revitalized thanks to, among others, the work and the scientific publications of Focardi and Rossi, which has been conducted in silence, amidst ironical disinterest, without any funding or support. In fact, recently, practical and reliable results have been achieved based on a very promising apparatus invented by Andrea Rossi. Therefore I want to examine the possibility of further development of this technology, which I deem really important for our planet. INTRODUCTION I will start with patent no./2009/125444, registered by Dr. Ing. Andrea Rossi. This invention and its performance have been tested and verified in collaboration with Prof. Sergio Focardi, as reported in their paper, published in February 2010 in the Journal of Nuclear Physics [1]. In this scientific paper they have reported on the performance of an apparatus, which has produced for two years substantial amounts of energy in a reliable and repeatable mode and they have also offered a theoretical analysis for the interpretation of the underlying physical mechanism. In the history of Science, it is not the first time that a practical and reliable apparatus is working before its theoretical foundation has been completely understood! The photoelectric effect is the classic example in which the application has anticipated its full theoretical interpretation, developed by Einstein. Afterwards Einstein, Plank, Heisenberg, De Broglie, Schrödinger and others formulated the principles of Quantum Mechanics. For the interactive Nickel/Hydrogen system it would be now opportune to compile, in a way easily understood by the non expert the, relevant principles and concepts for the qualitative understanding of the phenomenon as well as possible future research activities. CLASSICAL AND QUANTUM PHYSICS CONCEPTS Starting with the behavior of electrically charged particles in vacuum, it is known that particles with opposite electric charge attract themselves and “fuse” producing an electrically neutral particle, even though this does not always happen, as for instance in the case of a hydrogen atom, where a proton and a electron although attract each other they do not “fuse” for reasons out of the scope of this paper. On the contrary, particles charged with same sign of electric charge always repel each other, and their repulsion tends to infinity when their distance tends to zero, which implies that in this case fusion is not possible (classical physics). On the contrary, according to Quantum mechanics for a system with a great number of particles of the same electric charge (polarity) it is possible that a few of them will fuse, as for instance, according to Focardi-Rossi, in the case of Nickel nuclei in crystal structure and hydrogen nuclei (protons) diffused within it. Although of the same polarity, a very small percentage of these nuclei manage to come so close to each other, at a distance of 10-14 m, where strong nuclear forces emerge and take over the Coulomb forces and thus form the nucleus of a new element, either stable or unstable. This mechanism, which is possible only in the atomic microcosm, is predictable by a quantum-mechanics model of a particle put in a closed box. According to classical physics no one would expect to find a particle out of the box, but in quantum mechanics the probability that a particle is found out of the box is not zero! This probability is the so called “tunneling effect”, which for systems with a very large number of particles, predicts that a small percentage of them lie outside the box, having penetrated the “impenetrable” walls and any other present barrier through the “tunnel”! In our case, the barrier is nothing else but the electrostatic repulsion, to which the couples of hydrogen and nickel nuclei (of the same polarity) are subjected and is called Coulomb barrier. Diffusion mechanism of hydrogen in nickel: Nickel as a catalyst first decomposes the biatomic molecules of hydrogen to hydrogen atoms in contact with the nickel surface. Then these hydrogen atoms deposit their electrons in the conductivity band of the metal (Fermi band) and due to their greatly reduced volume, compared to that of their atom, the hydrogen nuclei readily diffuse into the crystalline structure of the nickel, including its defects. At this point, in order to understand the phenomenon it is necessary to briefly describe the structure both of the nickel atom and the nickel crystal lattice. It is well known that the nickel atom is not so simple as the hydrogen atom, as its nucleus consists of dozens of protons and neutrons, thus it is much heavier and exerts a proportionally higher electrostatic repulsion than the nucleus of hydrogen, which consists of only one proton. In this case, the electrons, numerically equal to the protons are ordered in various energy levels and can not be easily removed from the atom to which they belong. Exception to this rule is the case of electrons of the chemical bonds, which along with the electrons of the hydrogen atoms form the metal conductivity band (electronic cloud), which moves quasi freely throughout the metal mass. As in all transition metals the nickel atoms in the solid state, and more exactly their nuclei, are located at the vertices and at the centre of the six faces of the cubic cell of the metal, leaving a free internal octahedral space within the cell, which, on account of the quasi negligible volume of the nuclei, is practically filled with electrons of the nickel atoms, as well as with conductivity electrons. It would be really interesting to know the electrons specific density (number of electrons per unit volume) and its spatial distribution inside this octahedral space of the crystal lattice as a function of temperature. DYNAMICS OF THE LATTICE VIBRATION STATES Another important aspect to take into consideration in this system is the dynamics of the lattice vibration states, in other words, the periodic three dimensional normal oscillations of the crystal lattice (phonons) of the nickel, which hosts hydrogen nuclei or nuclei of hydrogen isotopes (deuterium or tritium) that have entered into the above mentioned free space of the crystal cell. It could be argued that the electron's specific density and its spatial distribution in the internal space of the crystal structure should be coherent with the natural frequencies of the lattice oscillations. This means that the periodicity of the electronic cloud within the octahedral space of the elementary crystal cell of Nickel generates an oscillating strengthening of shielding of the diffused nuclei of hydrogen or deuterium which also populate this space. I believe that these considerations can form the basis for a qualitative analysis of this “NEW SOURCE OF ENERGY” and the phenomenology related to cold fusion, including energy production in much smaller quantities and various reaction products. SHIELDING OF PROTONS BY ELECTRONS In the Focardi-Rossi paper the shielding of protons provided by electrons is suspected to be one of the main reasons of the effect, helping the capture of protons by the Ni nucleus, therefore generating energy by fusion of protons in Nickel and a series of exothermic nuclear reactions, leaving as by-product isotopes different from the original Ni (transmutations). Such shielding is one of the elements contributing to the energetic efficiency of the system. From this derives the opportunity, I think, to focus upon this shielding, both to increase its efficiency and to verify the hypothesis contained in the paper of Focardi-Rossi. Of course, what we are talking of here is a theoretical verification, because the practical verification is made by monitoring the performance of the apparatus invented and patented by Andrea Rossi, presently under rigorous verification in the USA, where a 1 MW unit is under construction. If we assume that the repulsive (Coulomb) effect can be overcome by the tunnel effect, which is promoted by the shielding provided by the cluster of electrons, in other words by the value of the specific density of the electron cloud in which the proton is immersed (partly neutralizing its electropositive charge), then the goal of our experiment should be to increase this density in the space where interactions of nuclei of hydrogen and nickel occur. In parallel, in order to establish a theoretical basis for the neutralization of protons, in my opinion, we have to resort to the Quark theory in the context of interactions between baryons and leptons. Nevertheless, by increasing the electrons specific density the enhanced partial neutralization of protons can be estimated by means of measurement of the produced energy. SUGGESTED THEMES FOR FUTURE RESEARCH Based on the above and with the aim to improve the understanding of the cold fusion phenomenon and its emerging applications, I would suggest the following two main themes of research: Interactive systems H/Ni Interactive systems D/Pd For the first system the experimental goal would be to increase the electron's specific density in the space where the nuclear reactions occur. The interactive spaces, in my opinion, would be two, i.e., on the surface and within the bulk of the Nickel. These spaces should function in different ways in relation to the mechanism of overcoming the repulsive Coulomb barrier (tunnel effect), which facilitates the fusion of the two nuclei, since the specific density of the shielding electrons is different in these two cases. I think that the specific density of the shielding electrons on the surfaces is lower than that within the “bulk -- however the direct contact of a larger number of protons with the nuclei of nickel atoms, which reside on the crystal faces, would statistically facilitate fusion. Therefore, in order to verify experimentally the Focardi-Rossi Theory we could work with various samples of Ni of different but well known grain size, and assuming that the Nickel crystals are approximately spherical we could correlate the resulting energy efficiency with the corresponding size of the total surface of the nickel grains in contact with hydrogen. We have previously assumed that the specific density of the shielding electrons on the surface is less than that in the bulk and if this is true, then the efficiency of the system should depend on the negative electrostatic field applied to the Ni, since such a negative field is present only on the surface of the Ni spheres, thus increasing this density. To experimentally verify this hypothesis we can proceed with a sample of pulverized Ni with known grain size and total global surface, layered homogeneously, but not excessively compact on a flat ceramic base. This could function as one of the two plates of a capacitor with negative polarity, while the other plate, with positive polarity, could be provided by a metal plate parallel to and above the Ni ceramic base, set at an appropriate distance which would ensure sufficient electric insulation between them. These plates will then be charged to a variable voltage, starting from very low levels for safety reasons. The maximum voltage to be applied will depend on the distance of the two plates but also on the dielectric constant of the hydrogen. Such tests, referred only to the interfacial nuclear effects, could verify the Focardi-Rossi Theory, but also control the efficiency of the reactor without any consumption of energy. At the beginning of this work we have also referred to the dynamics of the quantized vibration crystal lattice states, underlining that the periodical values of the specific density of the cluster of electrons inside the octahedral volume of the Ni atoms exerts an oscillatory shielding power on the protons of H or D diffused within this space. Ten or more years ago, while I was working on cold fusion in parallel with Sergio Focardi, I remember that when I talked to him about resonance, he told me “Resonance will reserve surprises for us!” I think that surprises are yet to come and we can deepen our knowledge on this subject by working in parallel in three directions: 1. Introduce and test the validity of other potential mechanisms of nuclear fusion between nickel and hydrogen nuclei confined within the crystal lattice of nickel. 2. Improve deuterium confinement within Palladium by introducing and testing the validity of potential mechanisms for overcoming the Coulomb barrier between two deuterium nuclei confined within the crystal lattice of Palladium (these are also subjected to the oscillating shielding power of the specific density of the electronic cloud within the Pd lattice). 3. Attempt to develop a unifying model for the mechanisms related to the overall phenomenology of cold fusion, in relation to the two above interactive systems. The proposal which follows is mainly based on experimental results, described briefly herein and published in an experimental thesis, obtained mostly in tests performed at the National Technical University of Athens in Greece, in 2000, while I was working there as a visiting Professor. Raman spectroscopy tests were performed on a Pd sample charged with Deuterium. It is known that metals don’t exhibit Raman spectra, and before our Pd sample was charged with D, it didn’t either. However, as the D nuclei diffused in the Pd lattice the Raman spectrum started to become evident, with a shape characteristic of the vibration dynamics of the system Pd-D wherein the peaks of the spectral profile were dependent on the quantity of the absorbed D nuclei. I believe that these spectra are due to discreet quantum vibration states of the Pd-D system, and can be utilized by means of the coherent electromagnetic resonance in order to increase and control the thermal “anomalies”, thus upgrading and controlling the produced energy. The vibration amplitude of the “Harmonic oscillator” has the same form, both within classical mechanics and quantum-mechanics context -- consequently electromagnetic fields of adjustable intensity (laser) and tunable to the Rammann spectral frequencies, which have been observed, could induce by resonance an enhanced compression of the oscillating crystal lattice. This would statistically enhance the overcoming of the Coulomb barrier and since the Pd lattice oscillation period is very long compared to nuclear reaction times, it would create conditions of cold fusion of this confined hydrogen isotope, trapped within Pd, thus producing He4+24 MeV of energy [2,3]. The research work which we have tried to present in a way understandable by the non specialist, is based on both theoretical and experimental aspects, among which first is the theory of quantum electrodynamics of Giuliano Preparatta and the oscillating shielding power of the electrons specific density on the deuterium nuclei diffused within the Pd crystal lattice. A graphic representation indicating the normal vibrations (phonons) of the three-dimensional harmonic oscillator, shown in Fig. 1, which as a model is closest to the lattice, should make it easier to understand the mechanisms of the nuclear reaction, however only on the external surface or within the 2-3 outer layers of the crystal structure. CONCLUSIONS In conclusion I think that the ideas for the promotion of a basic research programme should be listed in the following order: 1. For interactive H/Ni systems, the development of experiments regarding grain size and electrostatic field effects, which can be also useful for D/Pd systems. 2. Raman and infra red (IR) spectroscopy studies, of fundamental significance for the definition of the lattice vibration states of the H-Ni interactive system, demand sophisticated experimental techniques of multiple light wave reflections obtained by driving such waves through materials transparent to that light wavelength. A schematic example of the assembly of a cell for the study of IR and Rammann reflections spectroscopy from Ni, Pd, or other metal nanopowder is given in the Fig. 2. 3. For the experimental investigation of resonance in interactive Ni/H, D/Pd, or other systems, a pulsed laser system is needed, which can be tuned to the wavelength of the observed spectral profile, with variable peak power in the range of up to 200 W. I would like to conclude this contribution with an ancient Greek proverb of universal value: «ΟΙ ΚΑΙΡΟΙ ΟΥ ΜΕΝΕΤΟΙ», i.e., “times do not wait” ACKNOWLEDGEMENTS The author wishes to acknowledge Dr. A.G. Youtsos and Dr. Andrea Rossi for their contribution in formulating this paper in English REFERENCES 1. www. journal-of-nuclear-physics.com /Focardi Rossi 2. Antonella del Ninno, Antonio Frattolillo, Antonietta Rizzo, Rapporto Tecnico ENEA RT2002/41/FUS, ENEA – Unità Tecnico Scientifica Fusione; Centro Ricerche Frascati, Roma, 2002 3. Cold fusion – Wikipedia/Arata *AUTHOR’S BIOGRAPHICAL NOTE: Christos E. STREMMENOS is a retired Professor of the Department of Physical and Inorganic Chemistry of the Faculty of Industrial Chemistry in the University of Bologna. He has served as Ambassador of Greece in Italy (1982-1987), and has been awarded the title of “Cavaliere di Gran Croce al Merito” of the Italian Republic. In the University of Bologna, as well as in the Polytechnic of Athens (National Technical University of Athens) he has taught Molecular Spectroscopy, Applied Spectroscopy and Photochemistry. His research work, from the beginning of his academic career until the assumption of his duties as Greek Ambassador, was in the field of spectroscopy of both solid and liquid crystals and he studied their static and dynamic structure by employing quantum mechanics criteria. After his mission at the Embassy of Greece in Rome was completed, he tried to reproduce the Fleishmann-Pons Experiment, however he did not achieve reliable results and thus he started to work in the field of nuclear reactions between nickel and hydrogen or deuterium. http://www.journal-of-nuclear-physics.com/?p=338 Hydrogen/Nickel cold fusion probable mechanism by Prof. Ch. E. Stremmenos Leaving aside for the moment any rigorous theoretical approach based on quantitative analyses, I would like to focus, qualitatively only, on the subject of shielding of dispersed protons in the electronic cloud within the crystal structure. The Focardi-Rossi approach considers this shielding a basic requirement for surpassing the Coulomb barrier between the hydrogen nuclei (protons) and the Nickel lattice nuclei, resulting into release of energy, which is a fact, through a series of exothermic nuclear processes leading to transmutations, decays, etc. The reasoning presented in this note is based on elementary considerations of * The hydrogen atom (Bohr) in its fundamental energy state * The Heisenberg uncertainty principle * The high speed of nuclear reactions (10E-20 sec) The hydrogen atom (Bohr) in its fundamental state, in the absence of energy perturbations, remains indefinitely in its stationary state shown below. This is due to the in-phase wave (de Broglie), which follows the “circular” path of its single orbiting electron. The wave length and radius of the “circular” path are determined by the fundamental energy state of this atom. When hydrogen atoms come in contact with the metal (Ni), they abandon their stationary state as they deposit their electrons in the conductivity band of the metal, and due to their greatly reduced volume, compared to that of their atom, the hydrogen nuclei (naked protons) readily diffuse into the defects of the nickel crystalline structure as well as in tetrahedral or octahedral void spaces of the crystal lattice. It should be underlined that, in addition to the deposited hydrogen electrons, in the nickel mass included are also electrons of the chemical potential of the metal. Jointly these electrons constitute the conductivity electronic cloud, distributed in energy bands (Fermi), and quasi free to move throughout the metallic mass. In this dynamic state of “non-localized” plasma, based on the uncertainty principle (Heisenberg), it is conceivable that, for a very short time period (e.g. 10E-18 sec), a series of neutral mini atoms of hydrogen could be formed, in an unstable state, of various size and energy level, distributed within the Fermi band, which is enlarged due to the very short time (Heisenberg). The neutral mini-atoms of high energy and very short wave length -- which is in phase with the “cyclic” orbit (de Broglie) -- are statistically captured by the nickel nuclei of the crystal structure with the speed of nuclear reactions (10E-20 sec). For these mini-atoms to fuse with the nickel nuclei, apart from their neutral character for surpassing the Coulomb barrier, they must have dimensions smaller than 10E-14 m, where nuclear cohesion forces, of high intensity but very short range, are predominant. It is assumed that only a percentage of such atoms satisfy this condition (de Broglie). The above considerations are based only on an intuitive approach, and I trust this phenomenon could be tackled in a systematic and integrated way through the “theory of time dependent perturbations” by employing the appropriate Hamiltonian, which includes time: The mechanism proposed by Focardi -- Rossi, verified by mass spectroscopy data, which predicts transmutation of a nickel nucleus to an unstable copper nucleus (isotope), remains in principle valid. The difference is that inside the unstable copper nucleus, produced from the fusion of a hydrogen mini-atom with a nickel nucleus, is trapped the mini-atom electron (B-), which in my opinion undergoes in-situ annihilation, with the predicted (Focardi-Rossi) decay B+ of the new copper nucleus. The B+ and B- annihilation (interaction of matter and anti-matter) would lead to the emission of a high energy photon, g, (Einstein) from the nucleus of the now stable copper isotope and a neutoin to conserve the lepton number. However, based on the principle of conservation of momentum, as a result of the backlash of this nucleus, the photon energy g is divided into kinetic energy of this nucleus of large mass (heat) and a photon of lower frequency. Furthermore, it should be noted that the system does not exhibit the Mössbauer* phenomenon for two reasons: 1. The copper nucleus is not part of the nickel crystal structure, and behaves as an isolated atom in quasi gaseous state 2. Copper, as a chemical element, does not exhibit the Mössbauer phenomenon. In conclusion, it should be underlined that the copper nucleus thermal perturbation, as a result of its mechanical backlash(heat), is transferred to its encompassing nickel lattice and propagated, by in phase phonons (G. Preparata), through the entire nano-crystal. This could explain why in cold fusion the released energy is mainly in the form of heat and the produced (low) g radiation can be easily shielded. Prof. Ch. E. Stremmenos (ATHENS, DIC. 1910) December 12th, 2010 Rich Murray: 1. Does the integrity of the Ni lattice have to be maintained -- do damage, disruption, and melting impede the results?2. 2. If so, then a single or a few reactions in one nanograin of Ni may preclude further reactions within that grain -- what percentage of grains might be disabled per hour of normal heat production? 2. How many other elements, solid at various temperatures from cyrogenic to incandescent, might have similar results, with increased pressure and or temperature of H2 gas? 3. Could pressure alone be the major facilitating factor? 4. Wikipedia: hydrides Bonding Bonds between hydrogen and other elements range from highly covalent to somewhat ionic. Hydride compounds often do not conform to classical electron-counting rules, but are described as well as multi-centered bonds and metallic bonding. Hydrides can be components of discrete molecules, oligomers or polymers, ionic solids, chemisorped monolayers, bulk metals (interstitial), and other materials. While hydrides traditionally react as Lewis bases or reducing agents, some metal hydrides behave as hydrogen-atom donors and as acids Types of hydrides According to the general definition every element of the periodic table (except some noble gases) forms one or more hydrides. These compounds have been classified into three main types according to the nature of their bonding:[1] Ionic hydrides, which have significant ionic bonding character. Covalent hydrides, which include the hydrocarbons and many other compounds which covalently bond to hydrogen atoms. Interstitial hydrides, which may be described as having metallic bonding. While these divisions have not been used universally, they are still useful to understand differences in hydrides. Covalent hydrides: The more contemporary definition limits hydrides to hydrogen atoms that formally react as hydrides and hydrogen atoms bound to metal centers. In these substances the hydride bond is formally a covalent bond much like the bond made by a proton in a weak acid. his category includes hydrides that exist as discrete molecules, polymers or oligomers, and hydrogen that has been chem-adsorbed to a surface. Interstitial hydrides: Interstitial hydrides can exist as discrete molecules or metal clusters in which they are atomic centers in a defined multi-centered multi-electron bonds. Interstitial hydrides can also exist within bulk materials such as bulk metals or alloys at which point their bonding is generally considered metallic. Many bulk transition metals form interstitial binary hydrides when exposed to hydrogen. These systems are usually non-stoichiometric, with variable amounts of hydrogen atoms in the lattice. In materials engineering, the phenomenon of hydrogen embrittlement is a consequence of interstitial hydrides. A notable example of an interstitial binary hydrides is palladium which absorbs up to 900 times its own volume of hydrogen at room temperatures, forming palladium hydride, and has been considered as a means to carry hydrogen for vehicular fuel cells. Interstitial hydrides show certain promise as a way for safe hydrogen storage. During last 25 years many interstitial hydrides were developed that readily absorb and discharge hydrogen at room temperature and atmospheric pressure. They are usually based on intermetallic compounds and solid-solution alloys. However, their application is still limited, as they are capable of storing only about 2 weight percent of hydrogen, which is not enough for automotive applications. Metal hydride formation at pressures up to 1 Mbar A Driessen, P Sanger, H Hemmes and R Griessen Dept. of Appl. Phys., Twente Univ., Enschede, Netherlands Journal of Physics: Condensed Matter Volume 2, Number 49 A Driessen et al 1990 J. Phys.: Condens. Matter 2 9797 Issue 49 (10 December 1990) doi: 10.1088/0953-8984/2/49/007 Full text PDF (1.08 MB) Abstract A simple mean-field lattice gas model is used to predict the hydride formation properties of Cr, Mn, Fe, Co, Ni, Mo, Ru, Rh, Ir, W, Pt, Cu, Ag and Au, which at low hydrogen pressures absorb only small amounts of hydrogen. It is shown that with thermodynamic parameters determined from low-pressure data only (the molar standard heat of formation Delta Hx0 and the Einstein temperature Theta E of the interstitial hydrogen vibration) it is also possible to describe their high-pressure behaviour. As a result, the pressure-composition isotherms of these 14 metals are given for several temperatures and for pressures up to 1 Mbar. Where possible, comparison is made with experimental data. http://www.lenr-canr.org/acrobat/StormsEastudentsg.pdf Storms, E., A Student's Guide to Cold Fusion. 2003 55 pages Nickel is difficult to hydride because a diffusion barrier of the hydride is formed on the surface. However, repeated cycling will eventually break up the structure and allow conversion. Tritium was found in nickel wires after being electrically heated and cooled many times in hydrogen[118]. The resulting hydride layer, in which tritium was found, was 20-30 nm thick. 118. Sankaranarayanan, M., et al. Investigation of Low Level Tritium Generation in NiH2O Electrolytic Cells. in Fourth International Conference on Cold Fusion. 1993. Lahaina, Maui: Electric Power Research Institute 3412 Hillview Ave., Palo Alto, CA 94304. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2662468/ nt J Mol Sci. 2009 January; 10(1): 325–344. Published online 2009 January 15. doi: 10.3390/ijms10010325. PMCID: PMC2662468 Copyright © 2009 by the authors; licensee Molecular Diversity Preservation International, Basel, Switzerland. This article is an open-access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/3.0/). High Temperature Metal Hydrides as Heat Storage Materials for Solar and Related Applications Michael Felderhoff* and Borislav Bogdanović Max-Planck Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, 45470 Mülheim /Ruhr, Germany *Author to whom correspondence should be addressed; E-Mail: [hidden email]; Tel. +49 (0)208 306 2458 Received November 28, 2008; Revised January 8, 2009; Accepted January 13, 2009. This article is an open-access article distributed under the terms and conditions of the Creative Commons Attribution license (http://creativecommons.org/licenses/by/3.0/). Abstract For the continuous production of electricity with solar heat power plants the storage of heat at a temperature level around 400 °C is essential. High temperature metal hydrides offer high heat storage capacities around this temperature. Based on Mg-compounds, these hydrides are in principle low-cost materials with excellent cycling stability. Relevant properties of these hydrides and their possible applications as heat storage materials are described. Keywords: Hydrogen storage, heat storage, magnesium hydride, Mg2FeH6 ... full text included, 35 references ============================================================ FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org |
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