[en] An extensive first-principles study of fully exohydrogenated zigzag (n,0) and armchair (n,n) single-wall carbon nanotubes (C_nH_n), polyhedral molecules including cubane, dodecahedrane, and C₆₀H₆₀ points to crucial differences in the electronic and atomic structures relevant to hydrogen storage and device applications. C_nH_n's are estimated to be stable up to the radius of a (8,8) nanotube, with binding energies proportional to 1/R. Attaching a single hydrogen to any nanotube is always exothermic. Hydrogenation of zigzag nanotubes is found to be more likely than armchair nanotubes with similar radius. Our findings may have important implications for selective functionalization and finding a way of separating similar radius nanotubes from each other

No abstract available

[en] This book offers a simple and whole panorama of the production, the storage, the transport, the distribution and the conversion of the hydrogen into an energy (more specifically in electricity and fuel cells). It proposes also the possible applications of this energy in daily life and discusses a realistic evaluation of the possibilities of this channel (as the constraints bound to its development in the society). (A.L.B.)

[en] 'Full text': Liquid hydrogen is primarily used as a rocket fuel and is predestined for supersonic and hypersonic space vehicles to a large extent because it has the lowest boiling point density and the highest specific thrust of any known fuel. Its favorable characteristics include its high heating value per unit mass, its wide ignition range in hydrogen/oxygen or air mixtures, as well as its large flame speed and cooling capacity due to its high specific heat which permits very effective engine cooling and cooling the critical parts of the outer skin. Liquid hydrogen has some other important uses such as in high-energy nuclear physics and bubble chambers. The transport of hydrogen is vastly more economical when it is in liquid form even though cryogenic refrigeration and special Dewar vessels are required. Although liquid hydrogen can provide a lot of advantages, its uses are restricted in part because liquefying hydrogen by existing conventional methods consumes a large amount of energy (around 30% of its heating value). Liquefying 1 kg of hydrogen in a medium-size plant requires 10 to 13 kWh of electric energy. In addition, boil-off losses associated with the storage, transportation, and handling of liquid hydrogen can consume up to 40% of its available combustion energy. It is therefore important to search for ways that can improve the efficiency of the liquefiers and diminish the boil-off losses. This lecture gives an overview of the main issues associated with the production, storage, and handling of liquid hydrogen. Some discussion of promising ways of hydrogen liquefaction will also be presented. (author)

[en] This road-map proposes by the Group Total aims to inform the public on the hydrogen and fuel cells. It presents the hydrogen technology from the production to the distribution and storage, the issues as motor fuel and fuel cells, the challenge for vehicles applications and the Total commitments in the domain. (A.L.B.)

[en] Is the hydrogen economy of the future just another fish story? Absolutely not! There have been many changes affecting the energy equation over the last 10 years and conditions have changed. In this presentation, we examined the reasons why, in the very near future, hydrogen production and distribution will be increasingly visible on many industries' radar screens. Our presentation provides an overview of the fundamental energy triangle and its myriad opportunities. We will look at the excitement being generated by gasification, GTL, and the expected availability of 'cheap' hydrogen. We will seek to confirm that experimental projects are now behind us. We will demonstrate that we are ready to move rapidly towards the pre-commercial applications that will eventually provide significant savings and other benefits to a wide variety of industries. Beyond our ability to produce and deliver hydrogen, Air Liquide is an enabler of the H₂ economy. We are actively developing the H₂ architecture and infrastructure that will allow many Canadian firms - who have already demonstrated leadership in H₂ technologies - to expand their markets and grow into highly successful organizations. Air Liquide has the strength of 104 years of scientific achievement, technical excellence, and business success. The Air Liquide Group is dedicated to devoting the necessary resources - on both sides of the Atlantic and around the world - to ensure the successful implementation of a number of innovative H₂ projects. Our presentation includes a brief description of some of these projects. We think you will be surprised at their variety and impressed by how these projects are closely related to today's energy issues. We hope to convince you that the hydrogen economy of the future is filled with promise and potential. (author)

[en] 'Full text:' Previously, an LmNi5-based alloy was prepared and its hydrogenation properties were studied. In order to make use of such a type of metal hydride for application in PEMFC, the room-temperature desorption pressure has to be adjusted to 1-2atm and the cyclic stability has to be maintained. In this study, the same alloy was partially substituted with Al and cyclic hydrogenation was conducted with different hydrogen loadings up to 3000 cycles at room temperature. The saturated hydrogen loadings in equilibrium were controlled at H/M = 0.75 and 1.0. The P-C-T curves after 1000, 2000, and 3000 cycles of test were collected at T=30, 50, and 70^oC. After 3000 cycles, it is observed that the maximum hydrogenation capacities of the samples for the loadings of 0.75 and 1.0 are reduced to 0.93 and 0.91, respectively. The plateaus do not change much for T=30 and 50^oC, but become little sloped without observable split at 70^oC. X-ray diffraction analysis shows that the strains associated with repeated hydrogenation are isotropic for all samples. Both unsubstituted and Al-substituted alloys were then used to store hydrogen in a small cylinder with a diameter 10mm and length of 40 mm. The cylinder was connected to a small PEMFC for discharge test at room temperature. More than 540ml H2 was released at below 2atm and discharged to a capacity of 1200mAh. The hydrogenation properties of the alloys and design of the hydrogen storage cylinder for application in small portable PEMFCs for electronic devices are evaluated. The effect of Al substitution and hydrogen loading on cyclic hydrogenation property of the LmNi5-based alloy is also discussed. (author)

[en] Hydrogen is a very important molecule with an enormous breadth and extent of application and use. It is currently being used in many industries, from chemical and refining to metallurgical, glass and electronics. Hydrogen is primarily used as a reactant. But it is also being used as a fuel in space applications, as an ''O₂ scavenger'' in heat treating of metals and for its low viscosity and density. In this paper, current industrial uses of hydrogen in various industries in the industrial world will be summarized. Due to the increased use of heavier crude oils, containing higher amounts of sulfur and nitrogen and to meet stringent emission standards, need for hydrogen is experiencing a very rapid growth in the petroleum refining industry. Hence this application will be discussed in more detail. (author)

[en] 'Full text:' Hydrogen fueling demonstration projects are critical to the success of hydrogen as an automotive fuel by building public awareness and demonstrating the technology required to produce, store, and dispense hydrogen. Over 75 of these demonstration projects have been undertaken or are in the planning stages world-wide, sponsored by both the public and private sectors. Each of these projects represents a unique combination of sponsors, participants, geographic location, and hydrogen production pathway. QuestAir Technologies Inc., as the industry leader in compact pressure swing adsorption equipment for purifying hydrogen, has participated in four hydrogen fueling demonstration projects with a variety of partners and in North America and Japan. QuestAir's experiences as a participant in the planning, construction, and commissioning of these demonstration projects will be presented in this paper. The unique challenges of each project and the critical success factors that must to be considered for successful deployment of high-profile, international, and multi-vendor collaborations will also be discussed. The paper will also provide insights on the requirements for hydrogen fueling demonstration projects in the future. (author)

No abstract available