The Design of a Renewable Hydrogen Fuel Infrastructure for London

International Nuclear Information System (INIS)

Parissis, O.; Bauen, A.

2006-01-01

The development of a least cost hydrogen infrastructure is key to the introduction of hydrogen fuel in road transport. This paper presents a generic framework for modelling the development of a renewable hydrogen infrastructure that can be applied to different cases and geographical regions. The model was designed by means of mixed integer linear programming and developed in MATLAB. It was applied to the case of London aiming to examine the possibilities of developing a renewable hydrogen infrastructure within a 50 years time horizon. The results presented here are preliminary results from a study looking at the least cost solutions to supplying hydrogen produced exclusively from renewable energy resources to large urban centres. (authors)

New perspectives on renewable energy systems based on hydrogen

International Nuclear Information System (INIS)

Bose, T. K.; Agbossou, K.; Benard, P.; St-Arnaud, J-M.

1999-01-01

Current hydrocarbon-based energy systems, current energy consumption and the push towards the utilization of renewable energy sources, fuelled by global warming and the need to reduce atmospheric pollution are discussed. The consequences of climatic change and the obligation of Annex B countries to reduce their greenhouse gas emissions in terms of the Kyoto Protocols are reviewed. The role that renewable energy sources such as hydrogen, solar and wind energy could play in avoiding the most catastrophic consequences of rapidly growing energy consumption and atmospheric pollution in the face of diminishing conventional fossil fuel resources are examined. The focus is on hydrogen energy as a means of storing and transporting primary energy. Some favorable characteristics of hydrogen is its abundance, the fact that it can be produced utilizing renewable or non-renewable sources, and the further fact that its combustion produces three times more energy per unit of mass than oil, and six times more than coal. The technology of converting hydrogen into energy, storing energy in the form of hydrogen, and its utilization, for example in the stabilization of wind energy by way of electrolytic conversion to hydrogen, are described. Development at Hydro-Quebec's Institute of Research of a hydrogen-based autonomous wind energy system to produce electricity is also discussed. 2 tabs., 11 refs

Technoeconomic analysis of renewable hydrogen production, storage, and detection systems

Energy Technology Data Exchange (ETDEWEB)

Mann, M.K.; Spath, P.L.; Kadam, K. [National Renewable Energy Lab., Golden, CO (United States)

1996-10-01

Technical and economic feasibility studies of different degrees of completeness and detail have been performed on several projects being funded by the Department of Energy`s Hydrogen Program. Work this year focused on projects at the National Renewable Energy Laboratory, although analyses of projects at other institutions are underway or planned. Highly detailed analyses were completed on a fiber optic hydrogen leak detector and a process to produce hydrogen from biomass via pyrolysis followed by steam reforming of the pyrolysis oil. Less detailed economic assessments of solar and biologically-based hydrogen production processes have been performed and focused on the steps that need to be taken to improve the competitive position of these technologies. Sensitivity analyses were conducted on all analyses to reveal the degree to which the cost results are affected by market changes and technological advances. For hydrogen storage by carbon nanotubes, a survey of the competing storage technologies was made in order to set a baseline for cost goals. A determination of the likelihood of commercialization was made for nearly all systems examined. Hydrogen from biomass via pyrolysis and steam reforming was found to have significant economic potential if a coproduct option could be co-commercialized. Photoelectrochemical hydrogen production may have economic potential, but only if low-cost cells can be modified to split water and to avoid surface oxidation. The use of bacteria to convert the carbon monoxide in biomass syngas to hydrogen was found to be slightly more expensive than the high end of currently commercial hydrogen, although there are significant opportunities to reduce costs. Finally, the cost of installing a fiber-optic chemochromic hydrogen detection system in passenger vehicles was found to be very low and competitive with alternative sensor systems.

Bio-hydrogen production from renewable organic wastes

Energy Technology Data Exchange (ETDEWEB)

Shihwu Sung

2004-04-30

Methane fermentation has been in practice over a century for the stabilization of high strength organic waste/wastewater. Although methanogenesis is a well established process and methane--the end-product of methanogenesis is a useful energy source; it is a low value end product with relatively less energy content (about 56 kJ energy/g CH{sub 4}). Besides, methane and its combustion by-product are powerful greenhouse gases, and responsible for global climate change. So there is a pressing need to explore alternative environmental technologies that not only stabilize the waste/wastewater but also generate benign high value end products. From this perspective, anaerobic bioconversion of organic wastes to hydrogen gas is an attractive option that achieves both goals. From energy security stand point, generation of hydrogen energy from renewable organic waste/wastewater could substitute non-renewable fossil fuels, over two-third of which is imported from politically unstable countries. Thus, biological hydrogen production from renewable organic waste through dark fermentation represents a critically important area of bioenergy production. This study evaluated both process engineering and microbial physiology of biohydrogen production.

Storing in carbon nano structures for hybrid systems solar hydrogen

International Nuclear Information System (INIS)

Marazzi, R.; Zini, G.; Tartarini, P.

2009-01-01

We have developed a hybrid energy system for converting energy from renewable sources and its storage in the form of hydrogen. The storage uses activated carbon and the methodology was modelled mathematically and simulated in numerical software. The results show that storage compression is cheaper storage for liquefaction. [it

One million ton of hydrogen is the key piece in the Danish renewable energy puzzle

DEFF Research Database (Denmark)

Grandal, Rune Duban; Mathiesen, Brian Vad; Connolly, David

2013-01-01

Designing a 100 % renewable energy system (RES) for Denmark, the availability of a sustainable biomass resource potential is found to be a limiting factor. The biomass demand derives from specific needs in the system, i.e. 1) storable fuel for energy for balancing fluctuating power production, 2...... storage, i.e. storing wind power through electrolysis and further reaction of hydrogen to hydrocarbons with carbon feedstock from biomass. This involves biomass gasification and hydrogenation of the syngas or hydrogenation of recycled CO2. The advantage of hydro storage is a superior energy efficiency......) carbon feedstock for materials and chemicals and 3) energy dense fuels for the more demanding branches of the transportation sector such as aviation, ship freight and long distance road transportation. The challenge of balancing electricity over different timeslots comprise a short term balancing...

Exergetic life cycle assessment of hydrogen production from renewables

Science.gov (United States)

Granovskii, Mikhail; Dincer, Ibrahim; Rosen, Marc A.

Life cycle assessment is extended to exergetic life cycle assessment and used to evaluate the exergy efficiency, economic effectiveness and environmental impact of producing hydrogen using wind and solar energy in place of fossil fuels. The product hydrogen is considered a fuel for fuel cell vehicles and a substitute for gasoline. Fossil fuel technologies for producing hydrogen from natural gas and gasoline from crude oil are contrasted with options using renewable energy. Exergy efficiencies and greenhouse gas and air pollution emissions are evaluated for all process steps, including crude oil and natural gas pipeline transportation, crude oil distillation and natural gas reforming, wind and solar electricity generation, hydrogen production through water electrolysis, and gasoline and hydrogen distribution and utilization. The use of wind power to produce hydrogen via electrolysis, and its application in a fuel cell vehicle, exhibits the lowest fossil and mineral resource consumption rate. However, the economic attractiveness, as measured by a "capital investment effectiveness factor," of renewable technologies depends significantly on the ratio of costs for hydrogen and natural gas. At the present cost ratio of about 2 (per unit of lower heating value or exergy), capital investments are about five times lower to produce hydrogen via natural gas rather than wind energy. As a consequence, the cost of wind- and solar-based electricity and hydrogen is substantially higher than that of natural gas. The implementation of a hydrogen fuel cell instead of an internal combustion engine permits, theoretically, an increase in a vehicle's engine efficiency of about of two times. Depending on the ratio in engine efficiencies, the substitution of gasoline with "renewable" hydrogen leads to (a) greenhouse gas (GHG) emissions reductions of 12-23 times for hydrogen from wind and 5-8 times for hydrogen from solar energy, and (b) air pollution (AP) emissions reductions of 38

Solar hydrogen hybrid system with carbon storage

International Nuclear Information System (INIS)

Zini, G.; Marazzi, R.; Pedrazzi, S.; Tartarini, P.

2009-01-01

A complete solar hydrogen hybrid system has been developed to convert, store and use energy from renewable energy sources. The theoretical model has been implemented in a dynamic model-based software environment and applied to real data to simulate its functioning over a one-year period. Results are used to study system design and performance. A photovoltaic sub-system directly drives a residential load and, if a surplus of energy is available, an electrolyzer to produce hydrogen which is stored in a cluster of nitrogen-cooled tanks filled with AX-21 activated carbons. When the power converted from the sun is not sufficient to cover load needs, hydrogen is desorbed from activated carbon tanks and sent to the fuel-cell sub-system so to obtain electrical energy. A set of sub-systems (bus-bar, buck- and boost-converters, inverter, control circuits), handle the electrical power according to a Programmable Logic Control unit so that the load can be driven with adequate Quality of Service. Hydrogen storage is achieved through physisorption (weak van der Waals interactions) between carbon atoms and hydrogen molecules occurring at low temperature (77 K) in carbon porous solids at relatively low pressures. Storage modeling has been developed using a Langmuir-Freundlich 1st type isotherm and experimental data available in literature. Physisorption storage provides safer operations along with good gravimetric (10.8% at 6 MPa) and volumetric (32.5 g/l at 6 MPa) storage capacities at costs that can be comparable to, or smaller than, ordinary storage techniques (compression or liquefaction). Several test runs have been performed on residential user data-sets: the system is capable of providing grid independence and can be designed to yield a surplus production of hydrogen which can be used to recharge electric car batteries or fill tanks for non-stationary uses. (author)

Potential of producing renewable hydrogen from livestock animal waste. Paper no. IGEC-1-143

International Nuclear Information System (INIS)

Chang, F.

2005-01-01

Hydrogen economy and fuel cell technology have become increasingly recognized as means for maintaining a sustainable energy supply as well as a sustainable environment. Simultaneously, solutions are being sought to effectively manage the animal wastes from livestock farming of cattle, cow, hog, and poultry to ensure an environmentally sustainable method of food production. This discussion examines the potential of producing hydrogen from livestock waste on a scale that can effectively solve a waste management problem for the livestock industry and provide significant quantities of renewable hydrogen to the clean energy industry. The green energy derived from animal waste is considered to be carbon-neutral because animal feed is largely grown from photosynthesis of carbon dioxide. Electricity and heat thus generated will offset those generated from fossil fuels and can be rewarded with greenhouse gas emission reduction credits. Two groups of well proven technologies: biochemical processes such as anaerobic digestion (AD), and thermochemical processes such as gasification are considered in this paper. A theoretical analysis of the potential of reforming the biogas and syngas from these reactions has been conducted using mathematical models of AD, gasification, steam reforming and water-gas shift reactions, and the results indicate that significant quantities of renewable hydrogen can be generated to fuel clean energy technologies such as the fuel cell. Practical considerations are presented to complement the theoretical analysis and future research directions are also discussed. (author)

Renewable hydrogen production by catalytic steam reforming of peanut shells pyrolysis products

Energy Technology Data Exchange (ETDEWEB)

Evans, R.J.; Chornet, E.; Czernik, S.; Feik, C.; French, R.; Phillips, S. [National Renewable Energy Lab., Golden, CO (United States); Abedi, J.; Yeboah, Y.D. [Clark Atlanta Univ., Atlanta, GA (United States); Day, D.; Howard, J. [Scientific Carbons Inc., Blakely, GA (United States); McGee, D. [Enviro-Tech Enterprises Inc., Matthews, NC (United States); Realff, M.J. [Georgia Inst. of Technology, Atlanta, GA (United States)

2002-07-01

A project was initiated to determine the feasibility of producing hydrogen from agricultural wastes at a cost comparable to methane-reforming technologies. It is possible that hydrogen can be produced cost competitively with natural gas reforming by integrating hydrogen production with existing waste product utilization processes. This report presents initial results of an engineering demonstration project involving the development of a steam reforming process by a team of government, industrial and academic organizations working at the thermochemical facility at the National Renewable Energy Laboratory. The process is to be used on the gaseous byproducts from a process for making activated carbon from densified peanut shells. The reactor is interfaced with a 20 kg/hour fluidized-bed fast pyrolysis system and takes advantage of process chemical analysis and computer control and monitoring capacity. The reactor will be tested on the pyrolysis vapors produced in the activated carbon process. The final phase of the project will look at the production of hydrogen through the conversion of residual CO to H{sub 2} over a shift catalyst and separating hydrogen from CO{sub 2} using pressure swing adsorption. The purified oxygen will be mixed with natural gas and used for transportation purposes. The study demonstrates the potential impact of hydrogen and bioenergy on the economic development and diversification of rural areas. 11 refs., 2 tabs., 5 figs.

Coupling renewables via hydrogen into utilities: Temporal and spatial issues, and technology opportunities

Energy Technology Data Exchange (ETDEWEB)

Iannucci, J.J.; Horgan, S.A.; Eyer, J.M. [Distributed Utility Associates, San Ramon, CA (United States)] [and others

1996-10-01

This paper discusses the technical potential for hydrogen used as an energy storage medium to couple time-dependent renewable energy into time-dependent electric utility loads. This analysis will provide estimates of regional and national opportunities for hydrogen production, storage and conversion, based on current and near-term leading renewable energy and hydrogen production and storage technologies. Appropriate renewable technologies, wind, photovoltaics and solar thermal, are matched to their most viable regional resources. The renewables are assumed to produce electricity which will be instantaneously used by the local utility to meet its loads; any excess electricity will be used to produce hydrogen electrolytically and stored for later use. Results are derived based on a range of assumptions of renewable power plant capacity and fraction of regional electric load to be met (e.g., the amount of hydrogen storage required to meet the Northwest region`s top 10% of electric load). For each renewable technology national and regional totals will be developed for maximum hydrogen production per year and ranges of hydrogen storage capacity needed in each year (hydroelectric case excluded). The sensitivity of the answers to the fraction of peak load to be served and the land area dedicated for renewable resources are investigated. These analyses can serve as a starting point for projecting the market opportunity for hydrogen storage and distribution technologies. Sensitivities will be performed for hydrogen production, conversion. and storage efficiencies representing current and near-term hydrogen technologies.

Integrated Renewable Hydrogen Utility System (IRHUS) business plan

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-03-01

This business plan is for a proposed legal entity named IRHUS, Inc. which is to be formed as a subsidiary of Energy Partners, L.C. (EP) of West Palm Beach, Florida. EP is a research and development company specializing in hydrogen proton exchange membrane (PEM) fuel cells and systems. A fuel cell is an engine with no moving parts that takes in hydrogen and produces electricity. The purpose of IRHUS, Inc. is to develop and manufacture a self-sufficient energy system based on the fuel cell and other new technology that produces hydrogen and electricity. The product is called the Integrated renewable Hydrogen utility System (IRHUS). IRHUS, Inc. plans to start limited production of the IRHUS in 2002. The IRHUS is a unique product with an innovative concept in that it provides continuous electrical power in places with no electrical infrastructure, i.e., in remote and island locations. The IRHUS is a zero emissions, self-sufficient, hydrogen fuel generation system that produces electricity on a continuous basis by combining any renewable power source with hydrogen technology. Current plans are to produce a 10 kilowatt IRHUS MP (medium power). Future plans are to design and manufacture IRHUS models to provide power for a variety of power ranges for identified attractive market segments. The technological components of the IRHUS include an electrolyzer, hydrogen and oxygen storage subsystems, fuel cell system, and power control system. The IRHUS product is to be integrated with a variety of renewable energy technologies. 5 figs., 10 tabs.

Hydrogen from renewable sources. Current and future constraints

International Nuclear Information System (INIS)

Falchetta, M.; Galli, S.

2001-01-01

Using renewable energy sources to produce hydrogen as an energy vector could assure a fully sustainable renewable energy system with zero emissions. Many conversion technologies (in particular water electrolysis) are already available and proven, but are still far from being economically competitive [it

A renewable energy and hydrogen scenario for northern Europe

DEFF Research Database (Denmark)

Sørensen, Bent

2008-01-01

renewable energy supply system is demonstrated with the use of the seasonal reservoir-based hydrocomponents in the northern parts of the region. The outcome of the competition between biofuels and hydrogen in the transportation sector is dependent on the development of viable fuel cells and on efficient......A scenario based entirely on renewable energy with possible use of hydrogen as an energy carrier is constructed for a group of North European countries. Temporal simulation of the demand-supply matching is carried out for various system configurations. The role of hydrogen technologies for energy...... of energy trade between the countries, due to the different endowments of different countries with particular renewable energy sources, and to the particular benefit that intermittent energy sources, such as wind and solar, can derive from exchange of power. The establishment of a smoothly functioning...

Hydrogen from renewable resources - the hundred year commitment

International Nuclear Information System (INIS)

Adamson, K.A.

2004-01-01

During the last decade interest in a potential 'Hydrogen Economy' has increased and is now discussed in main stream literature and political debates. This is largely due to the promise that fuel cell technology, which uses a hydrogen-rich gas, has shown. Though hydrogen can be produced from a number of sources, it is steam reforming of natural gas that has gained a substantial support base, and is seen as an important bridge to a sustainable hydrogen production from renewable energy. What this paper examines is the synergy that exists now between hydrogen from renewable resources and the inception of the fuel cell market. It argues that although the natural gas pathway will be necessary for the short to medium term, there should not be a complete dominance of the production route. The paper also brings together a number of policy documents from the EU and argues that what is needed from the level of the EU is a long term, binding commitment to ensure that the natural gas pathway does not become locked in. (author)

Study the feasibility of hydrogen assisted renewable power for off-grid communities

International Nuclear Information System (INIS)

Wu, S.H.; Fleetwood, M.; Roberston, R.; Nielsen, N.

2004-01-01

Most Renewable energy sources lack the controllability and availability of conventional fossil fuel-based energy sources and therefore cannot meet load requirements of a community without a backup or storage system. The advances of hydrogen technologies enable these renewable energy options to supply power to remote communities relying on independent sources of electrical and other energy. The hydrogen assisted renewable power (HARP) concept promises to make renewable energy more practical and mainstream through the use of hydrogen based electrical generation systems. The study herein is the first of a multiphase project to investigate the benefits of HARP as an environmentally friendly replacement for diesel in the supply of electricity to off-grid communities and analyse its feasibility and suitability as a back-up power supply. A small-scale pilot project was selected and this study assesses the major elements of a plant required to integrate electrical generation system, hydrogen storage and hydrogen generation into a renewable energy generation system. Based on the available renewable energy profiles, a simulation model was developed to assist in selecting, integrating, and evaluating various configurations and operational scenarios. This paper describes the components of the proposed HARP system as well as its cost, benefits and opportunities for other applications. (author)

SISGR - Hydrogen Caged in Carbon-Exploration of Novel Carbon-Hydrogen Interactions

Energy Technology Data Exchange (ETDEWEB)

Lueking, Angela [Pennsylvania State Univ., State College, PA (United States); Badding, John [Pennsylvania State Univ., State College, PA (United States); Crespi, Vinent [Pennsylvania State Univ., State College, PA (United States)

2015-12-01

Hydrogen trapped in a carbon cage, captured through repulsive interactions, is a novel concept in hydrogen storage. Trapping hydrogen via repulsive interactions borrows an idea from macroscale hydrogen storage (i.e. compressed gas storage tanks) and reapplies these concepts on the nanoscale in specially designed molecular containers. Under extreme conditions of pressure, hydrogen solubility in carbon materials is expected to increase and carbon is expected to restructure to minimize volume via a mixed sp2/sp3 hydrogenated state. Thermodynamics dictate that pre-formed C-H structures will rearrange with increased pressure, yet the final carbon-hydrogen interactions may be dependent upon the mechanism by which hydrogen is introduced. Gas “trapping” is meant to denote gas present in a solid in a high density, adsorbed-like state, when the external pressure is much less than that necessary to provide a comparable fluid density. Trapping thus denotes a kinetically metastable state rather than thermodynamic equilibrium. This project probed mechanochemical means to polymerize select hydrocarbons in the presence of gases, in an attempt to form localized carbon cages that trap gases via repulsive interactions. Aromatic, polyaromatic, and hydroaromatic molecules expected to undergo cyclo-addition reactions were polymerized at high (~GPa) pressures to form extended hydrogenated amorphous carbon networks. Notably, aromatics with a pre-existing internal free volume (such as Triptycene) appeared to retain an internal porosity upon application of pressure. However, a high photoluminescence background after polymerization precluded in situ identification of trapped gases. No spectroscopic evidence was found after depressurization that would be indicative of pockets of trapped gases in a localized high-pressure environment. Control studies suggested this measurement may be insensitive to gases at low pressure. Similarly, no spectral fingerprint was found for gas-imbued spherical

Expert Opinion Analysis on Renewable Hydrogen Storage Systems Potential in Europe

Directory of Open Access Journals (Sweden)

Davide Astiaso Garcia

2016-11-01

Full Text Available Among the several typologies of storage technologies, mainly on different physical principles (mechanical, electrical and chemical, hydrogen produced by power to gas (P2G from renewable energy sources complies with chemical storage principle and is based on the conversion of electrical energy into chemical energy by means of the electrolysis of water which does not produce any toxic or climate-relevant emission. This paper aims to pinpoint the potential uses of renewable hydrogen storage systems in Europe, analysing current and potential locations, regulatory framework, governments’ outlooks, economic issues, and available renewable energy amounts. The expert opinion survey, already used in many research articles on different topics including energy, has been selected as an effective method to produce realistic results. The obtained results highlight strategies and actions to optimize the storage of hydrogen produced by renewables to face varying electricity demand and generation-driven fluctuations reducing the negative effects of the increasing share of renewables in the energy mix of European Countries.

''Green'' path from fossil-based to hydrogen economy: An overview of carbon-neutral technologies

Energy Technology Data Exchange (ETDEWEB)

Muradov, Nazim Z. [Florida Solar Energy Center, University of Central Florida, Cocoa, FL 32922 (United States); Veziroglu, T. Nejat [Clean Energy Research Institute, University of Miami, Coral Gables, FL 33124 (United States)

2008-12-15

While the dominant role of hydrogen in a sustainable energy future is widely accepted, the strategies for the transition from fossil-based to hydrogen economy are still actively debated. This paper emphasizes the role of carbon-neutral technologies and fuels during the transition period. To satisfy the world's growing appetite for energy and keep our planet healthy, at least 10 TW (or terawatt) of carbon-free power has to be produced by mid-century. Three prominent options discussed in the literature include: decarbonization of fossil energy, nuclear energy and renewable energy sources. These options are analyzed in this paper with a special emphasis on the role of hydrogen as a carbon-free energy carrier. In particular, the authors compare various fossil decarbonization strategies and evaluate the potential of nuclear and renewable energy resources to meet the 10 TW target. An overview of state-of-the-art technologies for production of carbon-free energy carriers and transportation fuels, and the assessment of their commercial potential is provided. It is shown that neither of these three options alone could provide 10 TW of carbon-neutral power without major changes in the existing infrastructure, and/or technological breakthroughs in many areas, and/or a considerable environmental risk. The authors propose a scenario for the transition from current fossil-based to hydrogen economy that includes two key elements: (i) changing the fossil decarbonization strategy from one based on CO{sub 2} sequestration to one that involves sequestration and/or utilization of solid carbon, and (ii) producing carbon-neutral synthetic fuels from bio-carbon and hydrogen generated from water using carbon-free sources (nuclear, solar, wind, geothermal). This strategy would allow taking advantage of the existing fuel infrastructure without an adverse environmental impact, and it would secure a smooth carbon-neutral transition from fossil-based to future hydrogen economy. (author)

A renewable energy based hydrogen demonstration park in Turkey. HYDEPARK

Energy Technology Data Exchange (ETDEWEB)

Ilhan, Niluefer; Ersoez, Atilla [TUEBITAK Marmara Research Center Energy Institute, Gebze Kocaeli (Turkey); Cubukcu, Mete [Ege Univ., Bornova, Izmir (Turkey). Solar Energy Inst.

2010-07-01

The main goal of this national project is to research hydrogen technologies and renewable energy applications. Solar and wind energy are utilized to obtain hydrogen via electrolysis, which can either be used in the fuel cell or stored in cylinders for further use. The management of all project work packages was carried by TUeBITAK Marmara Research Center (MRC) Energy Institute (EI) with the support of the collaborators. The aim of this paper is to present the units of the renewable energy based hydrogen demonstration park, which is in the demonstration phase now and share the experimental results. (orig.)

Renewable based hydrogen energy projects in remote and island communities

International Nuclear Information System (INIS)

Miles, S.; Gillie, M.

2009-01-01

Task 18 working group of the International Energy Agency's Hydrogen Implementing Agreement has been evaluating and documenting experiences with renewable based hydrogen energy projects in remote and island communities in the United Kingdom, Canada, Norway, Iceland, Gran Canaria, Spain and New Zealand. The objective was to examine the lessons learned from existing projects and provide recommendations regarding the effective development of hydrogen systems. In order to accomplish this task, some of the drivers behind the niche markets where hydrogen systems have already been developed, or are in the development stages, were studied in order to determine how these could be expanded and modified to reach new markets. Renewable based hydrogen energy projects for remote and island communities are currently a key niche market. This paper compared various aspects of these projects and discussed the benefits, objectives and barriers facing the development of a hydrogen-based economy

Hydrogen storage in carbon nanotubes.

Science.gov (United States)

Hirscher, M; Becher, M

2003-01-01

The article gives a comprehensive overview of hydrogen storage in carbon nanostructures, including experimental results and theoretical calculations. Soon after the discovery of carbon nanotubes in 1991, different research groups succeeded in filling carbon nanotubes with some elements, and, therefore, the question arose of filling carbon nanotubes with hydrogen by possibly using new effects such as nano-capillarity. Subsequently, very promising experiments claiming high hydrogen storage capacities in different carbon nanostructures initiated enormous research activity. Hydrogen storage capacities have been reported that exceed the benchmark for automotive application of 6.5 wt% set by the U.S. Department of Energy. However, the experimental data obtained with different methods for various carbon nanostructures show an extreme scatter. Classical calculations based on physisorption of hydrogen molecules could not explain the high storage capacities measured at ambient temperature, and, assuming chemisorption of hydrogen atoms, hydrogen release requires temperatures too high for technical applications. Up to now, only a few calculations and experiments indicate the possibility of an intermediate binding energy. Recently, serious doubt has arisen in relation to several key experiments, causing considerable controversy. Furthermore, high hydrogen storage capacities measured for carbon nanofibers did not survive cross-checking in different laboratories. Therefore, in light of today's knowledge, it is becoming less likely that at moderate pressures around room temperature carbon nanostructures can store the amount of hydrogen required for automotive applications.

Hydrogen adsorption in new carbon materials

International Nuclear Information System (INIS)

Zubizarreta, L.; Arenillas, A.; Rubiera, F.; Pis, J.J.

2006-01-01

Hydrogen physi-sorption on porous carbon materials is one among the different technologies which could be used for hydrogen storage. In addition hydrogen spillover on a carbon supports can enhance the hydrogen adsorption capacities obtained by physi-sorption. In this study two different carbon supports were synthesised: carbon gels and carbon microspheres. Carbon microspheres were doped with Ni(NO 3 ) 2 to study the hydrogen spillover on carbon support. The texture of the materials was characterised by CO 2 adsorption at 0 C and their hydrogen storage capacity was evaluated at -196 and 10 C with a Micromeritics Tristar 3000, and at room temperature with a high pressure gravimetric analyser. (authors)

Hydrogen adsorption in new carbon materials

Energy Technology Data Exchange (ETDEWEB)

Zubizarreta, L.; Arenillas, A.; Rubiera, F.; Pis, J.J. [Instituto Nacional del Carbon, CSIC, Apartado 73, 33080 Oviedo (Spain)

2006-07-01

Hydrogen physi-sorption on porous carbon materials is one among the different technologies which could be used for hydrogen storage. In addition hydrogen spillover on a carbon supports can enhance the hydrogen adsorption capacities obtained by physi-sorption. In this study two different carbon supports were synthesised: carbon gels and carbon microspheres. Carbon microspheres were doped with Ni(NO{sub 3}){sub 2} to study the hydrogen spillover on carbon support. The texture of the materials was characterised by CO{sub 2} adsorption at 0 C and their hydrogen storage capacity was evaluated at -196 and 10 C with a Micromeritics Tristar 3000, and at room temperature with a high pressure gravimetric analyser. (authors)

Hydrogen research and development in Hawaii: Hawaii natural energy institute's hydrogen from renewable resources research program

International Nuclear Information System (INIS)

McKinley, K.R.; Rocheleau, R.E.; Takahashi, P.K.; Jensen, C.M.

1993-01-01

Hawaii, an energy-vulnerable state, has launched a Renewable Resources Research Program, focusing on hydrogen production and storage; the main tasks of this effort are: photoelectrochemical production of hydrogen through the use of coated silicon electrodes; solar conversion and the production of hydrogen with cyanobacteria; improved hydrogen storage through the use of nonclassical poly-hydride metal complexes. 10 refs

Renewable hydrogen: carbon formation on Ni and Ru catalysts during ethanol steam-reforming

DEFF Research Database (Denmark)

Rass-Hansen, Jeppe; Christensen, Christina Hviid; Sehested, J.

2007-01-01

for the production of hydrogen is investigated, along with quantitative and qualitative determinations of carbon formation on the catalysts by TPO and TEM experiments. A Ru/ MgAl2O4 catalyst, a Ni/MgAl2O4 catalyst as well as Ag-and K-promoted Ni/ MgAl2O4 catalysts were studied. The operating temperature was between...... addition was a rapid deactivation of the catalyst due to an enhanced gum carbon formation on the Ni crystals. Contrary to this, the effect of K addition was a prolonged resistance against carbon formation and therefore against deactivation. The Ru catalyst operates better than all the Ni catalysts...

Hydrogen and Fuel Cells for IT Equipment

Energy Technology Data Exchange (ETDEWEB)

Kurtz, Jennifer

2016-03-09

With the increased push for carbon-free and sustainable data centers, data center operators are increasingly looking to renewable energy as a means to approach carbon-free status and be more sustainable. The National Renewable Energy Laboratory (NREL) is a world leader in hydrogen research and already has an elaborate hydrogen infrastructure in place at the Golden, Colorado, state-of-the-art data center and facility. This presentation will discuss hydrogen generation, storage considerations, and safety issues as they relate to hydrogen delivery to fuel cells powering IT equipment.

Hydrogen adsorption in carbon nanostructures compared

NARCIS (Netherlands)

Schimmel, H.G.; Nijkamp, M.G.; Kearley, G.J.; Rivera, A.; de Jong, K.P.; Mulder, F.M.

2004-01-01

Recent reports continue to suggest high hydrogen storage capacities for some carbon nanostructures due to a stronger interaction between hydrogen and carbon. Here the interaction of hydrogen with activated charcoal, carbon nanofibers, single walled carbon nanotubes (SWNT), and electron beam ‘opened’

Challenges for renewable hydrogen production

International Nuclear Information System (INIS)

Levin, D.B.; Chahine, R.

2009-01-01

The increasing demand for H 2 for heavy oil upgrading, desulfurization and upgrading of conventional petroleum, and for production of ammonium, in addition to the projected demand for H 2 as a transportation fuel and portable power, will require H 2 production on a massive scale. Increased production of H 2 by current technologies will consume greater amounts of conventional hydrocarbons (primarily natural gas) which in turn will generate greater greenhouse gas emissions. Production of H 2 from renewable sources derived from agricultural or other waste streams offers the possibility to contribute to the production capacity with lower or no net greenhouse gas emissions (without carbon sequestration technologies), increasing the flexibility and improving the economics of distributed and semi-centralized reforming. Electrolysis, thermo-catalytic, and biological production can be easily adapted to on-site decentralized production of H 2 , circumventing the need to establish a large and costly distribution infrastructure. Each of these H 2 production technologies, however, faces technical challenges, including conversion efficiencies, feedstock type, and the need to safely integrate H 2 production systems with H 2 purification and storage technologies. These issues are being addressed by H2CAN, a recently launched NSERC funded national strategic network in hydrogen production, purification, storage, infrastructure and safety. (author)

Study of a molten carbonate fuel cell combined heat, hydrogen and power system: Energy analysis

International Nuclear Information System (INIS)

Agll, Abdulhakim Amer A.; Hamad, Yousif M.; Hamad, Tarek A.; Thomas, Mathew; Bapat, Sushrut; Martin, Kevin B.; Sheffield, John W.

2013-01-01

Countries around the world are trying to use alternative fuels and renewable energy to reduce the energy consumption and greenhouse gas emissions. Biogas contains methane is considered a potential source of clean renewable energy. This paper discusses the design of a combined heat, hydrogen and power system, which generated by methane with use of Fuelcell, for the campus of Missouri University of Science and Technology located in Rolla, Missouri, USA. An energy flow and resource availability study was performed to identify sustainable type and source of feedstock needed to run the Fuelcell at its maximum capacity. FuelCell Energy's DFC1500 unit (a molten carbonate Fuelcell) was selected as the Fuelcell for the tri-generation (heat, hydrogen and electric power) system. This tri-generation system provides electric power to the campus, thermal energy for heating the anaerobic digester, and hydrogen for transportation, backup power and other applications on the campus. In conclusion, the combined heat, hydrogen and power system reduces fossil fuel usage, and greenhouse gas emissions at the university campus. -- Highlights: • Combined heat, hydrogen and power (CHHP) using a molten carbonate fuel cell. • Energy saving and alternative fuel of the products are determined. • Energy saving is increased when CHHP technology is implemented. • CHHP system reduces the greenhouse gas emissions and fuel consumption

Hydrogen Storage in Carbon Nano-materials

International Nuclear Information System (INIS)

David Eyler; Michel Junker; Emanuelle Breysse Carraboeuf; Laurent Allidieres; David Guichardot; Fabien Roy; Isabelle Verdier; Edward Mc Rae; Moulay Rachid Babaa; Gilles Flamant; David Luxembourg; Daniel Laplaze; Patrick Achard; Sandrine Berthon-Fabry; David Langohr; Laurent Fulcheri

2006-01-01

This paper presents the results of a French project related to hydrogen storage in carbon nano-materials. This 3 years project, co-funded by the ADEME (French Agency for the Environment and the Energy Management), aimed to assess the hydrogen storage capacity of carbon nano-materials. Four different carbon materials were synthesized and characterized in the frame of present project: - Carbon Nano-tubes; - Carbon Nano-fibres; - Carbon Aerogel; - Carbon Black. All materials tested in the frame of this project present a hydrogen uptake of less than 1 wt% (-20 C to 20 C). A state of the art of hydrogen storage systems has been done in order to determine the research trends and the maturity of the different technologies. The choice and design of hydrogen storage systems regarding fuel cell specifications has also been studied. (authors)

Renewable energy for hydrogen production and sustainable urban mobility

International Nuclear Information System (INIS)

Briguglio, N.; Andaloro, L.; Ferraro, M.; Di Blasi, A.; Dispenza, G.; Antonucci, V.; Matteucci, F.; Breedveld, L.

2010-01-01

In recent years, the number of power plants based on renewable energy (RWE) has been increasing and hydrogen as an energy carrier has become a suitable medium-to-long term storage solution as well as a ''fuel'' for FCEV's because of its CO 2 -free potential. In this context, the aim of the present study is to carry out both an economic and environmental analysis of a start-up RWE plant using a simulation code developed in previous work and a Life Cycle Assessment (LCA). The plant will be located in the South of Italy (Puglia) and will consist of different RWE sources (Wind Power, Photovoltaic, Biomass). RWE will be used to produce hydrogen from an electrolyzer, which will feed a fleet of buses using different fuels (methane, hydrogen, or a mixture of these). In particular, a wind turbine of 850 kW will feed a hydrogen production plant and a biomass plant will produce methane. Preliminary studies have shown that it is possible to obtain hydrogen at a competitive cost (DOE target) and that components (wind turbine, electrolyzer, vessel, etc.) influence the final price. In addition, LCA results have permitted a comparison of different minibuses using either fossil fuels or renewable energy sources. (author)

Renewable energy for hydrogen production and sustainable urban mobility

Energy Technology Data Exchange (ETDEWEB)

Briguglio, N.; Andaloro, L.; Ferraro, M.; Di Blasi, A.; Dispenza, G.; Antonucci, V. [Istituto di Tecnologie avanzate per l' Energia ' ' Nicola Giordano' ' Salita S, Lucia sopra Contesse, 5, 98126 Messina (Italy); Matteucci, F. [TRE SpA Tozzi Renewable Energy, Via Zuccherificio, 10, 48100 Mezzano (RA) (Italy); Breedveld, L. [2B Via della Chiesa Campocroce, 4, 31021 Mogliano Veneto (TV) (Italy)

2010-09-15

In recent years, the number of power plants based on renewable energy (RWE) has been increasing and hydrogen as an energy carrier has become a suitable medium-to-long term storage solution as well as a ''fuel'' for FCEV's because of its CO{sub 2}-free potential. In this context, the aim of the present study is to carry out both an economic and environmental analysis of a start-up RWE plant using a simulation code developed in previous work and a Life Cycle Assessment (LCA). The plant will be located in the South of Italy (Puglia) and will consist of different RWE sources (Wind Power, Photovoltaic, Biomass). RWE will be used to produce hydrogen from an electrolyzer, which will feed a fleet of buses using different fuels (methane, hydrogen, or a mixture of these). In particular, a wind turbine of 850 kW will feed a hydrogen production plant and a biomass plant will produce methane. Preliminary studies have shown that it is possible to obtain hydrogen at a competitive cost (DOE target) and that components (wind turbine, electrolyzer, vessel, etc.) influence the final price. In addition, LCA results have permitted a comparison of different minibuses using either fossil fuels or renewable energy sources. (author)

Renewable hydrocarbons for jet fuels from biomass and plastics via microwave-induced pyrolysis and hydrogenation processes

Science.gov (United States)

Zhang, Xuesong

This dissertation aims to enhance the production of aromatic hydrocarbons in the catalytic microwave-induced pyrolysis, and maximize the production of renewable cycloalkanes for jet fuels in the hydrogenation process. In the process, ZSM-5 catalyst as the highly efficient catalyst was employed for catalyzing the pyrolytic volatiles from thermal decomposition of cellulose (a model compound of lignocellulosic biomass). A central composite experiment design (CCD) was used to optimize the product yields as a function of independent factors (e.g. catalytic temperature and catalyst to feed mass ratio). The low-density polyethylene (a mode compound of waste plastics) was then carried out in the catalytic microwave-induced pyrolysis in the presence of ZSM-5 catalyst. Thereafter, the catalytic microwave-induced co-pyrolysis of cellulose with low-density polyethylene (LDPE) was conducted over ZSM-5 catalyst. The results showed that the production of aromatic hydrocarbons was significantly enhanced and the coke formation was also considerably reduced comparing with the catalytic microwave pyrolysis of cellulose or LDPE alone. Moreover, practical lignocellulosic biomass (Douglas fir sawdust pellets) was converted into aromatics-enriched bio-oil by catalytic microwave pyrolysis. The bio-oil was subsequently hydrogenated by using the Raney Ni catalyst. A liquid-liquid extraction step was implemented to recover the liquid organics and remove the water content. Over 20% carbon yield of liquid product regarding lignocellulosic biomass was obtained. Up to 90% selectivity in the liquid product belongs to jet fuel range cycloalkanes. As the integrated processes was developed, catalytic microwave pyrolysis of cellulose with LDPE was conducted to improve aromatic production. After the liquid-liquid extraction by the optimal solvent (n-heptane), over 40% carbon yield of hydrogenated organics based on cellulose and LDPE were achieved in the hydrogenation process. As such, real

Carbon credit of renewable energy projects in Malaysia

Science.gov (United States)

Lim, X.; Lam, W. H.; Shamsuddin, A. H.

2013-06-01

The introduction of Clean Development Mechanism (CDM) to Malaysia improves the environment of the country. Besides achieving sustainable development, the carbon credit earned through CDM enhances the financial state of the nation. Both CDM and renewable energy contribute to the society by striving to reduce carbon emission. Most of the CDM projects are related to renewable energy, which recorded 69% out of total CDM projects. This paper presents the energy overview and status of renewable energies in the country. Then, the renewable energy will be related to the CDM.

Carbon credit of renewable energy projects in Malaysia

International Nuclear Information System (INIS)

Lim, X; Lam, W H; Shamsuddin, A H

2013-01-01

The introduction of Clean Development Mechanism (CDM) to Malaysia improves the environment of the country. Besides achieving sustainable development, the carbon credit earned through CDM enhances the financial state of the nation. Both CDM and renewable energy contribute to the society by striving to reduce carbon emission. Most of the CDM projects are related to renewable energy, which recorded 69% out of total CDM projects. This paper presents the energy overview and status of renewable energies in the country. Then, the renewable energy will be related to the CDM.

Hydrogen storage properties of carbon nanomaterials and carbon containing metal hydrides

Energy Technology Data Exchange (ETDEWEB)

Maehlen, Jan Petter

2003-07-01

The topic of this thesis is structural investigations of carbon containing materials in respect to their hydrogen storage properties. This work was initially triggered by reports of extremely high hydrogen storage capacities of specific carbon nanostructures. It was decided to try to verify and understand the mechanisms in play in case of the existence of such high hydrogen densities in carbon. Two different routes towards the goal were employed; by studying selected hydrides with carbon as one of its constituents (mainly employing powder diffraction techniques in combination with hydrogen absorption and desorption measurements) and by carefully conducting hydrogen sorption experiments on what was believed to be the most ''promising'' carbon nanomaterial sample. In the latter case, a lot of effort was attributed to characterisations of different carbon nanomaterial containing samples with the aid of electron microscopy. Three different carbon-containing metal hydride systems, Y2C-H, YCoC-H and Y5SiC0.2-H, were examined. A relation between hydrogen occupation and the local arrangement of metal and carbon atoms surrounding the hydrogen sites was established. Several characteristic features of the compounds were noted in addition to solving the structure of the former unknown deuterideY5Si3C0.2D2.0 by the use of direct methods. Several carbon-nanomaterial containing samples were studied by means of transmission electron microscopy and powder diffraction, thus gaining knowledge concerning the structural aspects of nanomaterials. Based on these investigations, a specific sample containing a large amount of open-ended single-wall carbon nanotubes was chosen for subsequent hydrogen storage experiments. The latter experiments revealed moderate hydrogen storage capacities of the nanotubes not exceeding the values obtained for more conventional forms of carbon. These two different routes in investigating the hydrogen storage properties of carbon and carbon containing alloys

Hydrogen storage properties of carbon nanomaterials and carbon containing metal hydrides

Energy Technology Data Exchange (ETDEWEB)

Maehlen, Jan Petter

2003-07-01

The topic of this thesis is structural investigations of carbon containing materials in respect to their hydrogen storage properties. This work was initially triggered by reports of extremely high hydrogen storage capacities of specific carbon nanostructures. It was decided to try to verify and understand the mechanisms in play in case of the existence of such high hydrogen densities in carbon. Two different routes towards the goal were employed; by studying selected hydrides with carbon as one of its constituents (mainly employing powder diffraction techniques in combination with hydrogen absorption and desorption measurements) and by carefully conducting hydrogen sorption experiments on what was believed to be the most ''promising'' carbon nanomaterial sample. In the latter case, a lot of effort was attributed to characterisations of different carbon nanomaterial containing samples with the aid of electron microscopy. Three different carbon-containing metal hydride systems, Y2C-H, YCoC-H and Y5SiC0.2-H, were examined. A relation between hydrogen occupation and the local arrangement of metal and carbon atoms surrounding the hydrogen sites was established. Several characteristic features of the compounds were noted in addition to solving the structure of the former unknown deuterideY5Si3C0.2D2.0 by the use of direct methods. Several carbon-nanomaterial containing samples were studied by means of transmission electron microscopy and powder diffraction, thus gaining knowledge concerning the structural aspects of nanomaterials. Based on these investigations, a specific sample containing a large amount of open-ended single-wall carbon nanotubes was chosen for subsequent hydrogen storage experiments. The latter experiments revealed moderate hydrogen storage capacities of the nanotubes not exceeding the values obtained for more conventional forms of carbon. These two different routes in investigating the hydrogen storage properties of carbon and

Renewable carbohydrates are a potential high-density hydrogen carrier

Energy Technology Data Exchange (ETDEWEB)

Zhang, Y.-H. Percival [Biological Systems Engineering Department, 210-A Seitz Hall, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); Institute for Critical Technology and Applied Sciences (ICTAS), Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 (United States); DOE BioEnergy Science Center (BESC), Oak Ridge, TN 37831 (United States)

2010-10-15

The possibility of using renewable biomass carbohydrates as a potential high-density hydrogen carrier is discussed here. Gravimetric density of polysaccharides is 14.8 H{sub 2} mass% where water can be recycled from PEM fuel cells or 8.33% H{sub 2} mass% without water recycling; volumetric densities of polysaccharides are >100 kg of H{sup 2}/m{sup 3}. Renewable carbohydrates (e.g., cellulosic materials and starch) are less expensive based on GJ than are other hydrogen carriers, such as hydrocarbons, biodiesel, methanol, ethanol, and ammonia. Biotransformation of carbohydrates to hydrogen by cell-free synthetic (enzymatic) pathway biotransformation (SyPaB) has numerous advantages, such as high product yield (12 H{sub 2}/glucose unit), 100% selectivity, high energy conversion efficiency (122%, based on combustion energy), high-purity hydrogen generated, mild reaction conditions, low-cost of bioreactor, few safety concerns, and nearly no toxicity hazards. Although SyPaB may suffer from current low reaction rates, numerous approaches for accelerating hydrogen production rates are proposed and discussed. Potential applications of carbohydrate-based hydrogen/electricity generation would include hydrogen bioreactors, home-size electricity generators, sugar batteries for portable electronics, sugar-powered passenger vehicles, and so on. Developments in thermostable enzymes as standardized building blocks for cell-free SyPaB projects, use of stable and low-cost biomimetic NAD cofactors, and accelerating reaction rates are among the top research and development priorities. International collaborations are urgently needed to solve the above obstacles within a short time. (author)

Hydrogen, fuel cells and renewable energy integration in islands

International Nuclear Information System (INIS)

Bauen, A.; Hart, D.; Foradini, F.; Hart, D.

2002-01-01

Remote areas such as islands rely on costly and highly polluting diesel and heavy fuel oil for their electricity supply. This paper explored the opportunities for exploiting economically and environmentally viable renewable energy sources, in particular hydrogen storage, on such islands. In particular, this study focused on addressing the challenge of matching energy supply with demand and with technical issues regarding weak grids that are hindered with high steady state voltage levels and voltage fluctuations. The main technical characteristics of integrated renewable energy and hydrogen systems were determined by modelling a case study for the island of El Hierro (Canary Islands). The paper referred to the challenges regarding the technical and economic viability of such systems and their contribution to the economic development of remote communities. It was noted that energy storage plays an important role in addressing supply and demand issues by offering a way to control voltage and using surplus electricity at times of low load. Electrical energy can be stored in the form of potential or chemical energy. New decentralized generation technologies have also played a role in improving the energy efficiency of renewable energy sources. The feasibility of using hydrogen for energy storage was examined with particular reference to fuel-cell based energy supply in isolated island communities. 4 refs., 5 figs

Storage of Renewable Energy by Reduction of CO2 with Hydrogen.

Science.gov (United States)

Züttel, Andreas; Mauron, Philippe; Kato, Shunsuke; Callini, Elsa; Holzer, Marco; Huang, Jianmei

2015-01-01

The main difference between the past energy economy during the industrialization period which was mainly based on mining of fossil fuels, e.g. coal, oil and methane and the future energy economy based on renewable energy is the requirement for storage of the energy fluxes. Renewable energy, except biomass, appears in time- and location-dependent energy fluxes as heat or electricity upon conversion. Storage and transport of energy requires a high energy density and has to be realized in a closed materials cycle. The hydrogen cycle, i.e. production of hydrogen from water by renewable energy, storage and use of hydrogen in fuel cells, combustion engines or turbines, is a closed cycle. However, the hydrogen density in a storage system is limited to 20 mass% and 150 kg/m(3) which limits the energy density to about half of the energy density in fossil fuels. Introducing CO(2) into the cycle and storing hydrogen by the reduction of CO(2) to hydrocarbons allows renewable energy to be converted into synthetic fuels with the same energy density as fossil fuels. The resulting cycle is a closed cycle (CO(2) neutral) if CO(2) is extracted from the atmosphere. Today's technology allows CO(2) to be reduced either by the Sabatier reaction to methane, by the reversed water gas shift reaction to CO and further reduction of CO by the Fischer-Tropsch synthesis (FTS) to hydrocarbons or over methanol to gasoline. The overall process can only be realized on a very large scale, because the large number of by-products of FTS requires the use of a refinery. Therefore, a well-controlled reaction to a specific product is required for the efficient conversion of renewable energy (electricity) into an easy to store liquid hydrocarbon (fuel). In order to realize a closed hydrocarbon cycle the two major challenges are to extract CO(2) from the atmosphere close to the thermodynamic limit and to reduce CO(2) with hydrogen in a controlled reaction to a specific hydrocarbon. Nanomaterials with

State-scale evaluation of renewable electricity policy: The role of renewable electricity credits and carbon taxes

International Nuclear Information System (INIS)

Levin, Todd; Thomas, Valerie M.; Lee, Audrey J.

2011-01-01

We have developed a state-scale version of the MARKAL energy optimization model, commonly used to model energy policy at the US national scale and internationally. We apply the model to address state-scale impacts of a renewable electricity standard (RES) and a carbon tax in one southeastern state, Georgia. Biomass is the lowest cost option for large-scale renewable generation in Georgia; we find that electricity can be generated from biomass co-firing at existing coal plants for a marginal cost above baseline of 0.2-2.2 cents/kWh and from dedicated biomass facilities for 3.0-5.5 cents/kWh above baseline. We evaluate the cost and amount of renewable electricity that would be produced in-state and the amount of out-of-state renewable electricity credits (RECs) that would be purchased as a function of the REC price. We find that in Georgia, a constant carbon tax to 2030 primarily promotes a shift from coal to natural gas and does not result in substantial renewable electricity generation. We also find that the option to offset a RES with renewable electricity credits would push renewable investment out-of-state. The tradeoff for keeping renewable investment in-state by not offering RECs is an approximately 1% additional increase in the levelized cost of electricity. - Research Highlights: →We examine state-scale impacts of a renewable electricity standard and a carbon tax. →Georgia has low electricity prices and bioenergy is the main renewable option. →A carbon tax of $50/tCO 2 does not significantly increase renewable generation. →Renewable electricity credits divert renewable investment to other states. →Keeping renewable electricity generation in-state increases electricity costs by 1%.

Nanoengineered Carbon Scaffolds for Hydrogen Storage

Energy Technology Data Exchange (ETDEWEB)

Leonard, A. D.; Hudson, J. L.; Fan, H.; Booker, R.; Simpson, L. J.; O' Neill, K. J.; Parilla, P. A.; Heben, M. J.; Pasquali, M.; Kittrell, C.; Tour, J. M.

2009-01-01

Single-walled carbon nanotube (SWCNT) fibers were engineered to become a scaffold for the storage of hydrogen. Carbon nanotube fibers were swollen in oleum (fuming sulfuric acid), and organic spacer groups were covalently linked between the nanotubes using diazonium functionalization chemistry to provide 3-dimensional (3-D) frameworks for the adsorption of hydrogen molecules. These 3-D nanoengineered fibers physisorb twice as much hydrogen per unit surface area as do typical macroporous carbon materials. These fiber-based systems can have high density, and combined with the outstanding thermal conductivity of carbon nanotubes, this points a way toward solving the volumetric and heat-transfer constraints that limit some other hydrogen-storage supports.

Hydrogen: Fueling the Future

International Nuclear Information System (INIS)

Leisch, Jennifer

2007-01-01

As our dependence on foreign oil increases and concerns about global climate change rise, the need to develop sustainable energy technologies is becoming increasingly significant. Worldwide energy consumption is expected to double by the year 2050, as will carbon emissions along with it. This increase in emissions is a product of an ever-increasing demand for energy, and a corresponding rise in the combustion of carbon containing fossil fuels such as coal, petroleum, and natural gas. Undisputable scientific evidence indicates significant changes in the global climate have occurred in recent years. Impacts of climate change and the resulting atmospheric warming are extensive, and know no political or geographic boundaries. These far-reaching effects will be manifested as environmental, economic, socioeconomic, and geopolitical issues. Offsetting the projected increase in fossil energy use with renewable energy production will require large increases in renewable energy systems, as well as the ability to store and transport clean domestic fuels. Storage and transport of electricity generated from intermittent resources such as wind and solar is central to the widespread use of renewable energy technologies. Hydrogen created from water electrolysis is an option for energy storage and transport, and represents a pollution-free source of fuel when generated using renewable electricity. The conversion of chemical to electrical energy using fuel cells provides a high efficiency, carbon-free power source. Hydrogen serves to blur the line between stationary and mobile power applications, as it can be used as both a transportation fuel and for stationary electricity generation, with the possibility of a distributed generation energy infrastructure. Hydrogen and fuel cell technologies will be presented as possible pollution-free solutions to present and future energy concerns. Recent hydrogen-related research at SLAC in hydrogen production, fuel cell catalysis, and hydrogen

Synthesis of hydrogen-carbon clathrate material and hydrogen evolution therefrom at moderate temperatures and pressures

Science.gov (United States)

Lueking, Angela [State College, PA; Narayanan, Deepa [Redmond, WA

2011-03-08

A process for making a hydrogenated carbon material is provided which includes forming a mixture of a carbon source, particularly a carbonaceous material, and a hydrogen source. The mixture is reacted under reaction conditions such that hydrogen is generated and/or released from the hydrogen source, an amorphous diamond-like carbon is formed, and at least a portion of the generated and/or released hydrogen associates with the amorphous diamond-like carbon, thereby forming a hydrogenated carbon material. A hydrogenated carbon material including a hydrogen carbon clathrate is characterized by evolution of molecular hydrogen at room temperature at atmospheric pressure in particular embodiments of methods and compositions according to the present invention.

Hydrogen storage in carbon nanostruc

NARCIS (Netherlands)

Hirscher, M.; Becher, M.; Haluska, M.; Quintel, A.; Skakalova, V.; Choi, M.; Dettlaff-Weglikowska, U.; Roth, S.; Stepanek, I.; Bernier, P.; Leonhardt, A.; Fink, J.

2002-01-01

The paper gives a critical review of the literature on hydrogen storage in carbon nanostructures. Furthermore, the hydrogen storage of graphite, graphite nanofibers (GNFs), and single-walled carbon nanotubes (SWNTs) was measured by thermal desorption spectroscopy (TDS). The samples were ball milled

The role of renewable bioenergy in carbon dioxide sequestration

Energy Technology Data Exchange (ETDEWEB)

Kinoshita, C.M. [Hawaii Natural Energy Inst., Honolulu, HI (United States)

1993-12-31

The use of renewable resources represents a sound approach to producing clean energy and reducing the dependence on diminishing reserves of fossil fuels. Unfortunately, the widespread interest in renewable energy in the 1970s, spurred by escalating fossil fuel prices, subsided with the collapse of energy prices in the mid 1980s. Today, it is largely to reverse alarming environmental trends, particularly the buildup of atmospheric carbon dioxide, rather than to reduce the cost of energy, that renewable energy resources are being pursued. This discussion focuses on a specific class of renewable energy resources - biomass. Unlike most other classes of renewable energy touted for controlling atmospheric carbon dioxide concentrations, e.g., hydro, direct solar, wind, geothermal, and ocean thermal, which produce usable forms of energy while generating little or no carbon dioxide emissions, bioenergy almost always involves combustion and therefore generates carbon dioxide; however, if used on a sustained basis, bio-energy would not contribute to the build-up of atmospheric carbon dioxide because the amount released in combustion would be balanced by that taken up via photosynthesis. It is in that context, i.e., sustained production of biomass as a modern energy carrier, rather than reforestation for carbon sequestration, that biomass is being discussed here, since biomass can play a much greater role in controlling global warming by displacing fossil fuels than by being used strictly for carbon sequestration (partly because energy crop production can reduce fossil carbon dioxide emissions indefinitely, whereas under the reforestation strategy, carbon dioxide abatement ceases at forest maturity).

A Renewably Powered Hydrogen Generation and Fueling Station Community Project

Science.gov (United States)

Lyons, Valerie J.; Sekura, Linda S.; Prokopius, Paul; Theirl, Susan

2009-01-01

The proposed project goal is to encourage the use of renewable energy and clean fuel technologies for transportation and other applications while generating economic development. This can be done by creating an incubator for collaborators, and creating a manufacturing hub for the energy economy of the future by training both white- and blue-collar workers for the new energy economy. Hydrogen electrolyzer fueling stations could be mass-produced, shipped and installed in collaboration with renewable energy power stations, or installed connected to the grid with renewable power added later.

Hydrogen adsorption in carbon nanostructures compared

International Nuclear Information System (INIS)

Schimmel, H.G.; Nijkamp, G.; Kearley, G.J.; Rivera, A.; Jong, K.P. de; Mulder, F.M.

2004-01-01

Recent reports continue to suggest high hydrogen storage capacities for some carbon nanostructures due to a stronger interaction between hydrogen and carbon. Here the interaction of hydrogen with activated charcoal, carbon nanofibers, single walled carbon nanotubes (SWNT), and electron beam 'opened' SWNT are compared and shown to be similar. The storage capacity below 77 K of these materials correlates with the surface area of the material with the activated charcoal having the largest. SWNT and 'opened' SWNT have a relatively low accessible surface area due to bundling of the tubes. Pressure-temperature curves give the interaction potential, which was found to be ∼580 K or 50 meV in all samples, leading to significant adsorption below ∼50 K. Using the inelastic neutron scattering signal associated with rotation of the hydrogen molecule as a sensitive probe for the surroundings of the molecule, no difference was found between the hydrogen molecules adsorbed in the investigated materials. These combined spectroscopic and macroscopic results show that SWNT, nanofibers and activated carbons store molecular hydrogen due to their graphitic nature and not because they possess special morphologies. Results from a density functional theory computer calculation suggest molecular hydrogen bonding to an aromatic C-C bond of graphite, irrespective of the surface morphology farther away

Study of a molten carbonate fuel cell combined heat, hydrogen and power system

International Nuclear Information System (INIS)

Hamad, Tarek A.; Agll, Abdulhakim A.; Hamad, Yousif M.; Bapat, Sushrut; Thomas, Mathew; Martin, Kevin B.; Sheffield, John W.

2014-01-01

To address the problem of fossil fuel usage and high greenhouse gas emissions at the Missouri University of Science and Technology campus, using of alternative fuels and renewable energy sources can lower energy consumption and greenhouse gas emissions. Biogas, produced by anaerobic digestion of wastewater, organic waste, agricultural waste, industrial waste, and animal by-products is a potential source of renewable energy. In this work, we have discussed the design of CHHP (combined heat, hydrogen and power) system for the campus using local resources. An energy flow and resource availability study is performed to identify the type and source of feedstock required to continuously run the fuel cell system at peak capacity. Following the resource assessment study, the team selects FuelCell Energy DFC (direct fuel cell) 1500™ unit as a molten carbonate fuel cell. The CHHP system provides electricity to power the university campus, thermal energy for heating the anaerobic digester, and hydrogen for transportation, back-up power and other needs. In conclusion, the CHHP system will be able to reduce fossil fuel usage, and greenhouse gas emissions at the university campus. - Highlights: • A molten carbonate fuel cell tri-generation by using anaerobic digestion system. • Anaerobic digestion system will be able to supply fuel for the DFC1500™ unit. • Use locally available feedstock to production electric power, hydrogen and heat. • Application energy end-uses on the university. • CHHP system will reduce energy consumption, fossil fuel usage, and GHG emissions

National Renewable Energy Laboratory 2003 Research Review

Energy Technology Data Exchange (ETDEWEB)

2004-04-01

In-depth articles on several NREL technologies and advances, including: production of hydrogen using renewable resources and technologies; use of carbon nanotubes for storing hydrogen; enzymatic reduction of cellulose to simple sugars as a platform for making fuel, chemicals, and materials; and the potential of electricity from wind energy to offset carbon dioxide emissions. Also covered are NREL news, awards and honors received by the Laboratory, and patents granted to NREL researchers.

Hydrogen-based power generation from bioethanol steam reforming

Energy Technology Data Exchange (ETDEWEB)

Tasnadi-Asztalos, Zs., E-mail: tazsolt@chem.ubbcluj.ro; Cormos, C. C., E-mail: cormos@chem.ubbcluj.ro; Agachi, P. S. [Babes-Bolyai University, Faculty of Chemistry and Chemical Engineering, 11 Arany Janos, Postal code: 400028, Cluj-Napoca (Romania)

2015-12-23

This paper is evaluating two power generation concepts based on hydrogen produced from bioethanol steam reforming at industrial scale without and with carbon capture. The power generation from bioethanol conversion is based on two important steps: hydrogen production from bioethanol catalytic steam reforming and electricity generation using a hydrogen-fuelled gas turbine. As carbon capture method to be assessed in hydrogen-based power generation from bioethanol steam reforming, the gas-liquid absorption using methyl-di-ethanol-amine (MDEA) was used. Bioethanol is a renewable energy carrier mainly produced from biomass fermentation. Steam reforming of bioethanol (SRE) provides a promising method for hydrogen and power production from renewable resources. SRE is performed at high temperatures (e.g. 800-900°C) to reduce the reforming by-products (e.g. ethane, ethene). The power generation from hydrogen was done with M701G2 gas turbine (334 MW net power output). Hydrogen was obtained through catalytic steam reforming of bioethanol without and with carbon capture. For the evaluated plant concepts the following key performance indicators were assessed: fuel consumption, gross and net power outputs, net electrical efficiency, ancillary consumptions, carbon capture rate, specific CO{sub 2} emission etc. As the results show, the power generation based on bioethanol conversion has high energy efficiency and low carbon footprint.

Hydrogen-based power generation from bioethanol steam reforming

International Nuclear Information System (INIS)

Tasnadi-Asztalos, Zs.; Cormos, C. C.; Agachi, P. S.

2015-01-01

This paper is evaluating two power generation concepts based on hydrogen produced from bioethanol steam reforming at industrial scale without and with carbon capture. The power generation from bioethanol conversion is based on two important steps: hydrogen production from bioethanol catalytic steam reforming and electricity generation using a hydrogen-fuelled gas turbine. As carbon capture method to be assessed in hydrogen-based power generation from bioethanol steam reforming, the gas-liquid absorption using methyl-di-ethanol-amine (MDEA) was used. Bioethanol is a renewable energy carrier mainly produced from biomass fermentation. Steam reforming of bioethanol (SRE) provides a promising method for hydrogen and power production from renewable resources. SRE is performed at high temperatures (e.g. 800-900°C) to reduce the reforming by-products (e.g. ethane, ethene). The power generation from hydrogen was done with M701G2 gas turbine (334 MW net power output). Hydrogen was obtained through catalytic steam reforming of bioethanol without and with carbon capture. For the evaluated plant concepts the following key performance indicators were assessed: fuel consumption, gross and net power outputs, net electrical efficiency, ancillary consumptions, carbon capture rate, specific CO 2 emission etc. As the results show, the power generation based on bioethanol conversion has high energy efficiency and low carbon footprint

Hydrogen-based power generation from bioethanol steam reforming

Science.gov (United States)

Tasnadi-Asztalos, Zs.; Cormos, C. C.; Agachi, P. S.

2015-12-01

This paper is evaluating two power generation concepts based on hydrogen produced from bioethanol steam reforming at industrial scale without and with carbon capture. The power generation from bioethanol conversion is based on two important steps: hydrogen production from bioethanol catalytic steam reforming and electricity generation using a hydrogen-fuelled gas turbine. As carbon capture method to be assessed in hydrogen-based power generation from bioethanol steam reforming, the gas-liquid absorption using methyl-di-ethanol-amine (MDEA) was used. Bioethanol is a renewable energy carrier mainly produced from biomass fermentation. Steam reforming of bioethanol (SRE) provides a promising method for hydrogen and power production from renewable resources. SRE is performed at high temperatures (e.g. 800-900°C) to reduce the reforming by-products (e.g. ethane, ethene). The power generation from hydrogen was done with M701G2 gas turbine (334 MW net power output). Hydrogen was obtained through catalytic steam reforming of bioethanol without and with carbon capture. For the evaluated plant concepts the following key performance indicators were assessed: fuel consumption, gross and net power outputs, net electrical efficiency, ancillary consumptions, carbon capture rate, specific CO2 emission etc. As the results show, the power generation based on bioethanol conversion has high energy efficiency and low carbon footprint.

Carbon: Hydrogen carrier or disappearing skeleton?

International Nuclear Information System (INIS)

De Jong, K.P.; Van Wechem, H.M.H.

1994-01-01

The use of liquid hydrocarbons as energy carriers implies the use of carbon as a carrier for hydrogen to facilitate hydrogen transport and storage. The current trend for liquid energy carriers used in the transport sector is to maximize the load of hydrogen on the carbon carrier. The recently developed Shell Middle Distillate Hydrogenation process for the manufacture of high quality diesel from aromatic refinery streams fits this picture. In the future, the hydrogen required to raise the product H/C ratio will be increasingly produced via gasification of large amounts of heavy residues. In the light of the strong preference towards using liquid fuels in the transport sector, the Shell Middle Distillate Synthesis process to convert natural gas into diesel of very high quality is discussed. Finally, a few comments on the use of hydrogen without a carbon carrier are made. Long lead times and the likelihood of producing the 'first' hydrogen from fossil fuel are highlighted. 13 figs., 6 tabs., 5 refs

Implications of carbon cap-and-trade for US voluntary renewable energy markets

International Nuclear Information System (INIS)

Bird, Lori A.; Holt, Edward; Levenstein Carroll, Ghita

2008-01-01

Many consumers today are purchasing renewable energy in large part for the greenhouse gas (GHG) emissions benefits that they provide. Emerging carbon regulation in the US has the potential to affect existing markets for renewable energy. Carbon cap-and-trade programs are now under development in the Northeast under the Regional Greenhouse Gas Initiative (RGGI) and in early stages of development in the West and Midwest. There is increasing discussion about carbon regulation at the national level as well. While renewable energy will likely benefit from carbon cap-and-trade programs because compliance with the cap will increase the costs of fossil fuel generation, cap-and-trade programs can also impact the ability of renewable energy generation to affect overall CO 2 emissions levels and obtain value for those emissions benefits. This paper summarizes key issues for renewable energy markets that are emerging with carbon regulation, such as the implications for emissions benefits claims and voluntary market demand and the use of renewable energy certificates (RECs) in multiple markets. It also explores policy options under consideration for designing carbon policies to enable carbon markets and renewable energy markets to work together

Autonomous hydrogen power plants with renewable energy sources

International Nuclear Information System (INIS)

Popel', O.S.; Frid, S.E.; Shpil'rajn, Eh.Eh.; Izosimov, D.B.; Tumanov, V.L.

2006-01-01

One studies the principles to design independent hydrogen power plants (IHPP) operating on renewable energy sources and the approaches to design a pilot IHP plant. One worded tasks of mathematical simulation and of calculations to substantiate the optimal configuration of the mentioned plants depending on the ambient conditions of operation and on peculiar features of a consumer [ru

Renewable Hydrogen for Carbon-Free Data Center

Energy Technology Data Exchange (ETDEWEB)

Kurtz, Jennifer M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Ma, Zhiwen [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hammond, Steven W [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Wipke, Keith B [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Cader, T. [Hewlett Packard Enterprise

2017-11-28

NREL, in collaboration with Hewlett Packard Enterprise, has developed a system model for simulating both grid-tied and island microgrid power for hydrogen production and data center operation (assumed at 50 MW, 24 hours a day, 7 days a week).

Hydrogen production via catalytic processing of renewable feedstocks

International Nuclear Information System (INIS)

Nazim Muradov; Franklyn Smith; Ali T-Raissi

2006-01-01

Landfill gas (LFG) and biogas can potentially become important feedstocks for renewable hydrogen production. The objectives of this work were: (1) to develop a catalytic process for direct reforming of CH 4 -CO 2 gaseous mixture mimicking LFG, (2) perform thermodynamic analysis of the reforming process using AspenPlus chemical process simulator, (3) determine operational conditions for auto-thermal (or thermo-neutral) reforming of a model CH 4 -CO 2 feedstock, and (4) fabricate and test a bench-scale hydrogen production unit. Experimental data obtained from catalytic reformation of the CH 4 -CO 2 and CH 4 -CO 2 -O 2 gaseous mixtures using Ni-catalyst were in a good agreement with the simulation results. It was demonstrated that catalytic reforming of LFG-mimicking gas produced hydrogen with the purity of 99.9 vol.%. (authors)

An overview of renewable hydrogen production from thermochemical process of oil palm solid waste in Malaysia

International Nuclear Information System (INIS)

Hosseini, Seyed Ehsan; Wahid, Mazlan Abdul; Ganjehkaviri, A.

2015-01-01

Highlights: • 40% of energy demand of Malaysia could be supplied by thermochemical process of PSR. • SCWG of PSR is preferable thermochemical process due to char and tar elimination. • Potential of H 2 production from SCWG of PSR is 1.05 × 10 10 kgH 2 per year in Malaysia. • Highly moisturized PSR could be used in hydrogen production by SCWG process. - Abstract: Hydrogen is one of the most promising energy carriers for the future of the world due to its tremendous capability of pollution reduction. Hydrogen utilization is free of toxic gases formation as well as carbon dioxide (CO 2 ) emission. Hydrogen production can be implemented using a wide variety of resources including fossil fuels, nuclear energy and renewable and sustainable energy (RSE). Amongst various RSE resources, biomass has great capacity to be employed for renewable hydrogen production. Hydrogen production from palm solid residue (PSR) via thermochemical process is a perfect candidate for waste-to-well strategy in palm oil mills in Malaysia. In this paper, various characteristics of hydrogen production from thermochemical process of PSR includes pyrolysis and gasification are reviewed. The annual oil palm fruits production in Malaysia is approximately 100 million tonnes which the solid waste of the fruits is capable to generate around 1.05 × 10 10 kgH 2 (1.26 EJ) via supercritical water gasification (SCWG) process. The ratio of energy output to energy input of SCWG process of PSR is about 6.56 which demonstrates the priority of SCWG to transform the energy of PSR into a high energy end product. The high moisture of PSR which is the most important barrier for its direct combustion, emerges as an advantage in thermochemical reactions and highly moisturized PSR (even more than 50%) is utilized directly in SCWG without application of any high cost drying process. Implementation of appropriate strategies could lead Malaysia to supply about 40% of its annual energy demand by hydrogen yield from

Renewable hydrogen production via thermochemical/electrochemical coupling

Energy Technology Data Exchange (ETDEWEB)

Ambrosini, Andrea [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Babiniec, Sean Michael [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Miller, James E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-10-01

A coupled electrochemical/thermochemical cycle was investigated to produce hydrogen from renewable resources. Like a conventional thermochemical cycle, this cycle leverages chemical energy stored in a thermochemical working material that is reduced thermally by solar energy. However, in this concept, the stored chemical energy only needs to be partially, but not fully, capable of splitting steam to produce hydrogen. To complete the process, a proton-conducting membrane is driven to separate hydrogen as it is produced, thus shifting the thermodynamics toward further hydrogen production. This novel coupled-cycle concept provides several benefits. First, the required oxidation enthalpy of the reversible thermochemical material is reduced, enabling the process to occur at lower temperatures. Second, removing the requirement for spontaneous steam-splitting widens the scope of materials compositions, allowing for less expensive/more abundant elements to be used. Lastly, thermodynamics calculations suggest that this concept can potentially reach higher efficiencies than photovoltaic-to-electrolysis hydrogen production methods. This Exploratory Express LDRD involved assessing the practical feasibility of the proposed coupled cycle. A test stand was designed and constructed and proton-conducting membranes were synthesized. While the full proof of concept was not achieved, the individual components of the experiment were validated and new capabilities that can be leveraged by a variety of programs were developed.

Low carbon renewable natural gas production from coalbeds and implications for carbon capture and storage.

Science.gov (United States)

Huang, Zaixing; Sednek, Christine; Urynowicz, Michael A; Guo, Hongguang; Wang, Qiurong; Fallgren, Paul; Jin, Song; Jin, Yan; Igwe, Uche; Li, Shengpin

2017-09-18

Isotopic studies have shown that many of the world's coalbed natural gas plays are secondary biogenic in origin, suggesting a potential for gas regeneration through enhanced microbial activities. The generation of biogas through biostimulation and bioaugmentation is limited to the bioavailability of coal-derived compounds and is considered carbon positive. Here we show that plant-derived carbohydrates can be used as alternative substrates for gas generation by the indigenous coal seam microorganisms. The results suggest that coalbeds can act as natural geobioreactors to produce low carbon renewable natural gas, which can be considered carbon neutral, or perhaps even carbon negative depending on the amount of carbon sequestered within the coal. In addition, coal bioavailability is no longer a limiting factor. This approach has the potential of bridging the gap between fossil fuels and renewable energy by utilizing existing coalbed natural gas infrastructure to produce low carbon renewable natural gas and reducing global warming.Coalbeds produce natural gas, which has been observed to be enhanced by in situ microbes. Here, the authors add plant-derived carbohydrates (monosaccharides) to coal seams to be converted by indigenous microbes into natural gas, thus demonstrating a potential low carbon renewable natural gas resource.

Carbon compound used in hydrogen storage

International Nuclear Information System (INIS)

Iturbe G, J.L.; Lopez M, B.E.

2004-01-01

In the present work it is studied the activated carbon of mineral origin for the sorption of hydrogen. The carbon decreased of particle size by means of the one alloyed mechanical. The time of mill was of 10 hours. The characterization one carries out by scanning electron microscopy and X-ray diffraction. The hydrogen sipped in the carbon material it was determined using the Thermal gravimetric method (TGA). The conditions of hydrogenation went at 10 atm of pressure and ambient temperature during 18 hours. They were also carried out absorption/desorption cycles of hydrogen in the same one system of thermal gravimetric analysis. The results showed percentages of sorption of 2% approximately in the cycles carried out in the system TGA and of 4.5% in weight of hydrogen at pressure of 10 atmospheres and ambient temperature during 18 hours. (Author)

Compressor-less Hydrogen Transmission Pipelines Deliver Large-scale Stranded Renewable Energy at Competitive Cost

International Nuclear Information System (INIS)

W Leighty; J Holloway; R Merer; B Somerday; C San Marchi; G Keith; D White

2006-01-01

We assume a transmission-constrained world, where large new wind plants and other renewable energies must pay all transmission costs for delivering their energy to distant markets. We modeled a 1,000 MW (1 GW) (name plate) wind plant in the large wind resource of the North America Great Plains, delivering exclusively hydrogen fuel, via a new gaseous hydrogen (GH2) pipeline, to an urban market at least 300 km distant. All renewable electric energy output would be converted, at the source, to hydrogen, via 100 bar output electrolyzers, directly feeding the GH2 transmission pipeline without costly compressor stations at inlet or at midline. The new GH2 pipeline is an alternative to new electric transmission lines. We investigate whether the pipeline would provide valuable energy storage. We present a simple model by which we estimate the cost of wind-source hydrogen fuel delivered to the distant city gate in year 2010, at GW scale. Ammonia, synthetic hydrocarbons, and other substances may also be attractive renewable-source energy carriers, storage media, and fuels; they are not considered in this paper. (authors)

Hydrogen retention in carbon-tungsten co-deposition layer formed by hydrogen RF plasma

International Nuclear Information System (INIS)

Katayama, K.; Kawasaki, T.; Manabe, Y.; Nagase, H.; Takeishi, T.; Nishikawa, M.

2006-01-01

Carbon-tungsten co-deposition layers (C-W layers) were formed by sputtering method using hydrogen or deuterium RF plasma. The deposition rate of the C-W layer by deuterium plasma was faster than that by hydrogen plasma, where the increase of deposition rate of tungsten was larger than that of carbon. This indicates that the isotope effect on sputtering-depositing process for tungsten is larger than that for carbon. The release curve of hydrogen from the C-W layer showed two peaks at 400 deg. C and 700 deg. C. Comparing the hydrogen release from the carbon deposition layer and the tungsten deposition layer, it is considered that the increase of the release rate at 400 deg. C is affected by tungsten and that at 700 deg. C is affected by carbon. The obtained hydrogen retention in the C-W layers which have over 60 at.% of carbon was in the range between 0.45 and 0.16 as H/(C + W)

Hydrogen storage property of nanoporous carbon aerogels

International Nuclear Information System (INIS)

Shen Jun; Liu Nianping; Ouyang Ling; Zhou Bin; Wu Guangming; Ni Xingyuan; Zhang Zhihua

2011-01-01

Carbon aerogels were prepared from resorcinol and formaldehyde via sol-gel process, high temperature carbonization and atmospheric pressure drying technology with solvent replacement. By changing the resorcinol-sodium carbonate molar ratio and the mass fraction of the reactants,resorcinol and formaldehyde, the pore structure of carbon aerogels can be controlled and the palladium-doped carbon aerogels were prepared.By transmission electron microscopy (TEM), X-ray diffraction (XRD) spectra, it is confirmed that the Pd exists in the skeleton structure of carbon aerogels as a form of nano simple substance pellet. The specific surface area is successfully raised by 2 times, and palladium-doped carbon aerogels with a specific surface area of 1 273 m 2 /g have been obtained by carrying out the activation process as the post-processing to the doped carbon aerogels. The hydrogen adsorption results show that the saturated hydrogen storage mass fraction of the carbon aerogels with the specific surface area of 3 212 m 2 /g is 3% in the condition of 92 K, 3.5 MPa, and 0.84% in the condition of 303 K, 3.2 MPa. In addition, the hydrogen adsorption test of palladium-doped carbon aerogels at room temperature (303 K) shows that the total hydrogen storage capacity of doped carbon aerogels is declined due to the relative small specific surface, but the hydrogen storage of unit specific surface area is enhanced. (authors)

Optimizing the Binding Energy of Hydrogen on Nanostructured Carbon Materials through Structure Control and Chemical Doping

Energy Technology Data Exchange (ETDEWEB)

Jie Liu

2011-02-01

The DOE Hydrogen Sorption Center of Excellence (HSCoE) was formed in 2005 to develop materials for hydrogen storage systems to be used in light-duty vehicles. The HSCoE and two related centers of excellence were created as follow-on activities to the DOE Office of Energy Efficiency and Renewable Energy’s (EERE’s) Hydrogen Storage Grand Challenge Solicitation issued in FY 2003. The Hydrogen Sorption Center of Excellence (HSCoE) focuses on developing high-capacity sorbents with the goal to operate at temperatures and pressures approaching ambient and be efficiently and quickly charged in the tank with minimal energy requirements and penalties to the hydrogen fuel infrastructure. The work was directed at overcoming barriers to achieving DOE system goals and identifying pathways to meet the hydrogen storage system targets. To ensure that the development activities were performed as efficiently as possible, the HSCoE formed complementary, focused development clusters based on the following four sorption-based hydrogen storage mechanisms: 1. Physisorption on high specific surface area and nominally single element materials 2. Enhanced H2 binding in Substituted/heterogeneous materials 3. Strong and/or multiple H2 binding from coordinated but electronically unsatruated metal centers 4. Weak Chemisorption/Spillover. As a member of the team, our group at Duke studied the synthesis of various carbon-based materials, including carbon nanotubes and microporous carbon materials with controlled porosity. We worked closely with other team members to study the effect of pore size on the binding energy of hydrogen to the carbon –based materials. Our initial project focus was on the synthesis and purification of small diameter, single-walled carbon nanotubes (SWNTs) with well-controlled diameters for the study of their hydrogen storage properties as a function of diameters. We developed a chemical vapor deposition method that synthesized gram quantities of carbon nanotubes with

Feasibility of hydrogen from renewable energy in the Arctic

International Nuclear Information System (INIS)

Chauhan, B.

2004-01-01

'Full text:' There is an abundance of renewable resources in the Canadian Arctic. Despite that diesel is still the conventional source used by homes and businesses for their electrical and space heating needs. Electrolysis of water to produce hydrogen using renewable resources is under investigation. A techno-economic feasibility has been conducted for hybrid systems including wind turbine, photovoltaic system, electrolyser and fuel cells. Different scenarios have been considered for meeting the needs of a small, remote community in the Arctic. Results will be presented indicating the most cost-effective Wind-PV-Electrolyser-Fuel Cell system for combined heat and power. (author)

Carbon Dioxide-Free Hydrogen Production with Integrated Hydrogen Separation and Storage.

Science.gov (United States)

Dürr, Stefan; Müller, Michael; Jorschick, Holger; Helmin, Marta; Bösmann, Andreas; Palkovits, Regina; Wasserscheid, Peter

2017-01-10

An integration of CO 2 -free hydrogen generation through methane decomposition coupled with hydrogen/methane separation and chemical hydrogen storage through liquid organic hydrogen carrier (LOHC) systems is demonstrated. A potential, very interesting application is the upgrading of stranded gas, for example, gas from a remote gas field or associated gas from off-shore oil drilling. Stranded gas can be effectively converted in a catalytic process by methane decomposition into solid carbon and a hydrogen/methane mixture that can be directly fed to a hydrogenation unit to load a LOHC with hydrogen. This allows for a straight-forward separation of hydrogen from CH 4 and conversion of hydrogen to a hydrogen-rich LOHC material. Both, the hydrogen-rich LOHC material and the generated carbon on metal can easily be transported to destinations of further industrial use by established transport systems, like ships or trucks. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Theoretical Study of Renewable Ionic Liquids in the Pure State and with Graphene and Carbon Nanotubes.

Science.gov (United States)

García, Gregorio; Atilhan, Mert; Aparicio, Santiago

2015-09-17

The N-ethyl-N-(furan-2-ylmethyl)ethanaminium dihydrogen phosphate ionic liquid was studied as a model of ionic liquids which can be produced from totally renewable sources. A computational study using both molecular dynamics and density functional theory methods was carried out. The properties, structuring, and intermolecular interactions (hydrogen bonding) of this fluid in the pure state were studied as a function of pressure and temperature. Likewise, the adsorption on graphene and the confinement between graphene sheets was also studied. The solvation of single walled carbon nanotubes in the selected ionic liquid was analyzed together with the behavior of ions confined inside these nanotubes. The reported results show remarkable properties for this fluid, which show that many of the most relevant properties of ionic liquids and their ability to interact with carbon nanosystems may be maintained and even improved using new families of renewable compounds instead of classic types of ionic liquids with worse environmental, toxicological, and economical profiles.

Ion beam analysis of hydrogen retained in carbon nanotubes and carbon films

International Nuclear Information System (INIS)

McDaniel, F.D.; Holland, O.W.; Naab, F.U.; Mitchell, L.J.; Dhoubhadel, M.; Duggan, J.L.

2006-01-01

Carbon nanotubes (CNTs) are studied as a possible hydrogen storage medium for future energy needs. Typically, hydrogen is stored in the CNTs by exposure of the material to a high-pressure H 2 atmosphere at different temperatures. The maximum hydrogen concentrations stored following this method and measured using ion beam analysis do not exceed 1 wt.%. Introduction of defects by ion irradiation (i.e. implantation) prior to high-pressure H 2 treatment, offers an alternative method to activate H adsorption and enhance the chemisorption of hydrogen. This is a preliminary work where hydrogen was introduced into single-wall nanotubes and carbon films by low-energy (13.6 keV) hydrogen ion implantation. Elastic recoil detection was used to measure the quantity and depth distribution of hydrogen retained in the carbonaceous materials. Results show that there are substantial differences in the measured profiles between the CNT samples and the vitreous carbon. On another hand, only ∼43% of the implanted hydrogen in the CNTs is retained in the region where it should be located according to the SRIM simulations for a solid carbon sample

State-level renewable electricity policies and reductions in carbon emissions

International Nuclear Information System (INIS)

Prasad, Monica; Munch, Steven

2012-01-01

A wide range of renewable electricity policies has been adopted at the state level in the United States, but to date there has been no large-scale, empirical assessment of the effect of these policies on carbon emissions. Such an assessment is important because scholars have pointed out that increases in renewable electricity will not necessarily lead to declines in carbon emissions. We examine the effects of a range of policies across 39 states. We find significant and robust decreases in carbon emissions associated with the introduction of public benefit funds, a form of “carbon tax” adopted by 19 states to date. Our aim in this paper is not to provide a final judgment on these policies, many of which may not have been in place long enough to show strong effects, but to shift the attention of the research community away from proximate measures such as increases in clean electricity generation and onto measurement of lower carbon emissions. - Highlights: ► We ask whether state-level renewable electricity policies in the United States have succeeded in lowering carbon emissions. ► We examine net metering, retail choice, fuel generation disclosure, mandatory green power options, public benefit funds, and renewable portfolio standards. ► The introduction of public benefit funds, a kind of carbon tax, is associated with decreases in carbon emissions.

The Palm Desert renewable [hydrogen] transportation system

Energy Technology Data Exchange (ETDEWEB)

Chamberlin, C.E.; Lehman, P. [Humboldt State Univ., Arcata, CA (United States). Schatz Energy Research Center

1998-08-01

This paper describes the Schatz Energy Research Center (SERC) progress on the Palm Desert Renewable Hydrogen Transportation System Project for the period June 1997 through May 1998. The project began in March 1996. The goal of the Palm Desert Project is to develop a clean and sustainable transportation system for a community. The project demonstrates the practical utility of hydrogen as a transportation fuel and the proton exchange membrane (PEM) fuel cell as a vehicle power system. The project includes designing and building 4 fuel cell powered vehicles, a solar hydrogen generating and refueling station, and a fuel cell vehicle diagnostic center. Over this last year, SERC has built a fuel cell powered neighborhood electric vehicle and delivered it to the City of Palm Desert. The design of the hydrogen refueling station is near completion and it is anticipated that construction will be complete in the fall of 1998. The vehicles are currently being refueled at a temporary refueling station. The diagnostic center is being designed and maintenance procedures as well as computer diagnostic programs for the fuel cell vehicles are being developed. City employees are driving the vehicles daily and monitoring data are being collected. The drivers are pleased with the performance of the vehicles.

Renewable Hydrogen Potential from Biogas in the United States

Energy Technology Data Exchange (ETDEWEB)

Saur, G.; Milbrandt, A.

2014-07-01

This analysis updates and expands upon previous biogas studies to include total potential and net availability of methane in raw biogas with respect to competing demands and includes a resource assessment of four sources of biogas: (1) wastewater treatment plants, including domestic and a new assessment of industrial sources; (2) landfills; (3) animal manure; and (4) a new assessment of industrial, institutional, and commercial sources. The results of the biogas resource assessment are used to estimate the potential production of renewable hydrogen from biogas as well as the fuel cell electric vehicles that the produced hydrogen might support.

Carbon neutral archipelago – 100% renewable energy supply for the Canary Islands

International Nuclear Information System (INIS)

Gils, Hans Christian; Simon, Sonja

2017-01-01

Highlights: • A pathway to a 100% renewable energy supply for the Canary Islands is presented. • Hourly system operation is analysed, considering flexibility options and sector linkage. • Results show feasibility of a carbon neutral energy supply with local resources. • High resolution power system model highlights importance of grid connections. - Abstract: As many other small islands and archipelagos, the Canary Islands depend to a high degree on energy imports. Despite its small surface, the archipelago has a high potential for renewable energy (RE) technologies. In this paper, we present a scenario pathway to a 100% RE supply in the Canary Islands by 2050. It relies on a back-casting approach linking the bottom-up accounting framework Mesap-PlaNet and the high resolution power system model REMix. Our analysis shows that locally available technology potentials are sufficient for a fully renewable supply of the islands’ power, heat, and land transport energy demands. To follow the pathway for achieving a carbon neutral supply, expansion of RE technology deployment needs to be accelerated in the short-term and efforts towards greater energy efficiency must be increased. According to our results, an extended linkage between energy sectors through electric vehicles as well as electric heating, and the usage of synthetic hydrogen can contribute notably to the integration of intermittent RE power generation. Furthermore, our results highlight the importance of power transmission in RE supply systems. Supply costs are found 15% lower in a scenario considering sea cable connections between all islands.

Low Cost Carbon Fiber From Renewable Resources

International Nuclear Information System (INIS)

Compere, A.L.

2001-01-01

The Department of Energy Partnership for a New Generation of Vehicles has shown that, by lowering overall weight, the use of carbon fiber composites could dramatically decrease domestic vehicle fuel consumption. For the automotive industry to benefit from carbon fiber technology, fiber production will need to be substantially increased and fiber price decreased to$7/kg. To achieve this cost objective, alternate precursors to pitch and polyacrylonitrile (PAN) are being investigated as possible carbon fiber feedstocks. Additionally, sufficient fiber to provide 10 to 100 kg for each of the 13 million cars and light trucks produced annually in the U.S. will require an increase of 5 to 50-fold in worldwide carbon fiber production. High-volume, renewable or recycled materials, including lignin, cellulosic fibers, routinely recycled petrochemical fibers, and blends of these components, appear attractive because the cost of these materials is inherently both low and insensitive to changes in petroleum price. Current studies have shown that a number of recycled and renewable polymers can be incorporated into melt-spun fibers attractive as carbon fiber feedstocks. Highly extrudable lignin blends have attractive yields and can be readily carbonized and graphitized. Examination of the physical structure and properties of carbonized and graphitized fibers indicates the feasibility of use in transportation composite applications

Storage of hydrogen in nanostructured carbon materials

OpenAIRE

Yürüm, Yuda; Yurum, Yuda; Taralp, Alpay; Veziroğlu, T. Nejat; Veziroglu, T. Nejat

2009-01-01

Recent developments focusing on novel hydrogen storage media have helped to benchmark nanostructured carbon materials as one of the ongoing strategic research areas in science and technology. In particular, certain microporous carbon powders, carbon nanomaterials, and specifically carbon nanotubes stand to deliver unparalleled performance as the next generation of base materials for storing hydrogen. Accordingly, the main goal of this report is to overview the challenges, distinguishing trait...

DEVELOPMENT OF DOPED NANOPOROUS CARBONS FOR HYDROGEN STORAGE

Energy Technology Data Exchange (ETDEWEB)

Lueking, Angela D.; Li, Qixiu; Badding, John V.; Fonseca, Dania; Gutierrez, Humerto; Sakti, Apurba; Adu, Kofi; Schimmel, Michael

2010-03-31

Hydrogen storage materials based on the hydrogen spillover mechanism onto metal-doped nanoporous carbons are studied, in an effort to develop materials that store appreciable hydrogen at ambient temperatures and moderate pressures. We demonstrate that oxidation of the carbon surface can significantly increase the hydrogen uptake of these materials, primarily at low pressure. Trace water present in the system plays a role in the development of active sites, and may further be used as a strategy to increase uptake. Increased surface density of oxygen groups led to a significant enhancement of hydrogen spillover at pressures less than 100 milibar. At 300K, the hydrogen uptake was up to 1.1 wt. % at 100 mbar and increased to 1.4 wt. % at 20 bar. However, only 0.4 wt% of this was desorbable via a pressure reduction at room temperature, and the high lowpressure hydrogen uptake was found only when trace water was present during pretreatment. Although far from DOE hydrogen storage targets, storage at ambient temperature has significant practical advantages oner cryogenic physical adsorbents. The role of trace water in surface modification has significant implications for reproducibility in the field. High-pressure in situ characterization of ideal carbon surfaces in hydrogen suggests re-hybridization is not likely under conditions of practical interest. Advanced characterization is used to probe carbon-hydrogen-metal interactions in a number of systems and new carbon materials have been developed.

Carbon deposition and hydrogen retention in tokamak

International Nuclear Information System (INIS)

Tanabe, Tetsuo

2006-01-01

The results of measurements on co-deposition of hydrogen isotopes and wall materials, hydrogen retention, redeposition of carbon and deposition of hydrogen on PMI of JT-60U are described. From above results, selection of plasma facing material and ability of carbon wall is discussed. Selection of plasma facing materials in fusion reactor, characteristics of carbon materials as the plasma facing materials, erosion, transport and deposition of carbon impurity, deposition of tritium in JET, results of PMI in JT-60, application of carbon materials to PFM of ITER, and future problems are stated. Tritium co-deposition in ITER, erosion and transport of carbon in tokamak, distribution of tritium deposition on graphite tile used as bumper limiter of TFTR, and measurement results of deposition of tritium on the Mark-IIA divertor tile and comparison between them are described. (S.Y.)

Sizing Hydrogen Energy Storage in Consideration of Demand Response in Highly Renewable Generation Power Systems

Directory of Open Access Journals (Sweden)

Mubbashir Ali

2018-05-01

Full Text Available From an environment perspective, the increased penetration of wind and solar generation in power systems is remarkable. However, as the intermittent renewable generation briskly grows, electrical grids are experiencing significant discrepancies between supply and demand as a result of limited system flexibility. This paper investigates the optimal sizing and control of the hydrogen energy storage system for increased utilization of renewable generation. Using a Finnish case study, a mathematical model is presented to investigate the optimal storage capacity in a renewable power system. In addition, the impact of demand response for domestic storage space heating in terms of the optimal sizing of energy storage is discussed. Finally, sensitivity analyses are conducted to observe the impact of a small share of controllable baseload production as well as the oversizing of renewable generation in terms of required hydrogen storage size.

Hydrogen in energy transition

International Nuclear Information System (INIS)

2016-02-01

This publication proposes a rather brief overview of challenges related to the use of hydrogen as an energy vector in the fields of transports and of energy storage to valorise renewable energies. Processes (steam reforming of natural gas or bio-gas, alkaline or membrane electrolysis, biological production), installation types (centralised or decentralised), raw materials and/or energy (natural gas, water, bio-gas, electricity, light), and their respective industrial maturity are indicated. The role of hydrogen to de-carbonate different types of transports is described (complementary energy for internal combustion as well as electrical vehicles) as well as its role in the valorisation and integration of renewable energies. The main challenges faced by the hydrogen sector are identified and discussed, and actions undertaken by the ADEME are indicated

Confinement of hydrogen at high pressure in carbon nanotubes

Science.gov (United States)

Lassila, David H [Aptos, CA; Bonner, Brian P [Livermore, CA

2011-12-13

A high pressure hydrogen confinement apparatus according to one embodiment includes carbon nanotubes capped at one or both ends thereof with a hydrogen-permeable membrane to enable the high pressure confinement of hydrogen and release of the hydrogen therethrough. A hydrogen confinement apparatus according to another embodiment includes an array of multi-walled carbon nanotubes each having first and second ends, the second ends being capped with palladium (Pd) to enable the high pressure confinement of hydrogen and release of the hydrogen therethrough as a function of palladium temperature, wherein the array of carbon nanotubes is capable of storing hydrogen gas at a pressure of at least 1 GPa for greater than 24 hours. Additional apparatuses and methods are also presented.

Electrochemical Hydrogen Storage in a Highly Ordered Mesoporous Carbon

Directory of Open Access Journals (Sweden)

Dan eLiu

2014-10-01

Full Text Available A highly order mesoporous carbon has been synthesized through a strongly acidic, aqueous cooperative assembly route. The structure and morphology of the carbon material were investigated using TEM, SEM and nitrogen adsorption-desorption isotherms. The carbon was proven to be meso-structural and consisted of graphitic micro-domain with larger interlayer space. AC impedance and electrochemical measurements reveal that the synthesized highly ordered mesoporous carbon exhibits a promoted electrochemical hydrogen insertion process and improved capacitance and hydrogen storage stability. The meso-structure and enlarged interlayer distance within the highly ordered mesoporous carbon are suggested as possible causes for the enhancement in hydrogen storage. Both hydrogen capacity in the carbon and mass diffusion within the matrix were improved.

The impact of carbon sequestration on the production cost of electricity and hydrogen from coal and natural-gas technologies in Europe in the medium term

International Nuclear Information System (INIS)

Tzimas, Evangelos; Peteves, Stathis D.

2005-01-01

Carbon sequestration is a distinct technological option with a potential for controlling carbon emissions; it complements other measures, such as improvements in energy efficiency and utilization of renewable energy sources. The deployment of carbon sequestration technologies in electricity generation and hydrogen production will increase the production costs of these energy carriers. Our economic assessment has shown that the introduction of carbon sequestration technologies in Europe in 2020, will result in an increase in the production cost of electricity by coal and natural gas technologies of 30-55% depending on the electricity-generation technology used; gas turbines will remain the most competitive option for generating electricity; and integrated gasification combined cycle technology will become competitive. When carbon sequestration is coupled with natural-gas steam reforming or coal gasification for hydrogen production, the production cost of hydrogen will increase by 14-16%. Furthermore, natural-gas steam reforming with carbon sequestration is far more economically competitive than coal gasification

Hydrogen storage using microporous carbon materials

International Nuclear Information System (INIS)

B Buczek; E Wolak

2005-01-01

temperatures than liquefaction. Last years have brought the interest in hydrogen storage in porous carbon materials, caused by the design and accessibility of new materials, such as fullerenes, carbon nano-tubes and nano-fibers. In particular the tubular carbon structures are perspective highly adsorbing materials, for their surface adsorption (on the internal and external surface of the nano-tubes), and for the effect of capillary condensation. Data presented in Table 1 show that the amount of hydrogen adsorbed on these new materials depends of their modification and on the type of carbon precursor. In this work the concept of hydrogen storage by adsorption was analyzed. The discussion is based on measurements of hydrogen adsorption on commercial active carbon in the temperature range 77 - 298 K at pressures up to 4 MPa. The amount of gas that can be stored in an adsorption system depends on the adsorbent characteristics and the operating conditions. Adsorption method was compared with another one taking into account both technical and economical aspects. The results show that the adsorption technique could provide a viable method for hydrogen storage

Analysis of an Improved Solar-Powered Hydrogen Generation System for Sustained Renewable Energy Production

Science.gov (United States)

2017-12-01

hydrogen gas by electrolysis. In LT Aviles’ design , distilled water was collected from the ambient air using Peltier dehumidifiers, manufactured by...Figure 13 shows the shelfing along with the entire system. Figure 13. Reconfigured Hydrogen Production Facility Because the system was designed for...POWERED HYDROGEN GENERATION SYSTEM FOR SUSTAINED RENEWABLE ENERGY PRODUCTION by Sen Feng Yu December 2017 Thesis Advisor: Garth V. Hobson Co

Questioning hydrogen

International Nuclear Information System (INIS)

Hammerschlag, Roel; Mazza, Patrick

2005-01-01

As an energy carrier, hydrogen is to be compared to electricity, the only widespread and viable alternative. When hydrogen is used to transmit renewable electricity, only 51% can reach the end user due to losses in electrolysis, hydrogen compression, and the fuel cell. In contrast, conventional electric storage technologies allow between 75% and 85% of the original electricity to be delivered. Even when hydrogen is extracted from gasified coal (with carbon sequestration) or from water cracked in high-temperature nuclear reactors, more of the primary energy reaches the end user if a conventional electric process is used instead. Hydrogen performs no better in mobile applications, where electric vehicles that are far closer to commercialization exceed fuel cell vehicles in efficiency, cost and performance. New, carbon-neutral energy can prevent twice the quantity of GHG's by displacing fossil electricity than it can by powering fuel cell vehicles. The same is true for new, natural gas energy. New energy resources should be used to displace high-GHG electric generation, not to manufacture hydrogen

Hydrogen adsorption on partially oxidised microporous carbons

International Nuclear Information System (INIS)

J B Parra; C O Ania; C J Duran Valle; M L Sanchez; C Otero Arean

2005-01-01

The search for cost effective adsorbents for large scale gas separation, storage and transport constitutes a present day strategic issue in the energy sector, propelled mainly by the potential use of hydrogen as an energy vector in a sustainable (and cleaner) energy scenario. Both, activated carbons and carbon based nano-structured materials have been proposed as potential candidates for reversible hydrogen storage in cryogenically cooled vessels. For that purpose, surface modification so as to enhance the gas solid interaction energy is desirable. We report on hydrogen adsorption on microporous (active) carbons which have been partially oxidised with nitric acid and ammonium persulfate. From the corresponding hydrogen adsorption isotherms (Fig. 1) an isosteric heat of about 3 kJ mol -1 was derived. This value is in agreement with that of about 3 to 4 kJ mol -1 obtained by quantum chemical calculations on the interaction between the hydrogen molecule and simple model systems (Fig. 2) of both, hydroxyl and carboxyl groups. Further research is in progress with a view to further increases the gas solid interaction energy. However, the values so far obtained are significantly larger than the liquefaction enthalpy of hydrogen: 0.90 kJ mol -1 ; and this is relevant to both, hydrogen separation from gas mixtures and cryogenic hydrogen storage. (authors)

Using renewables and the co-production of hydrogen and electricity from CCS-equipped IGCC facilities, as a stepping stone towards the early development of a hydrogen economy

International Nuclear Information System (INIS)

Haeseldonckx, Dries; D'haeseleer, William

2010-01-01

In this paper, specific cases for the interaction between the future electricity-generation mix and a newly-developing hydrogen-production infrastructure is modelled with the model E-simulate. Namely, flexible integrated-gasification combined-cycle units (IGCC) are capable of producing both electricity and hydrogen in different ratios. When these units are part of the electricity-generation mix and when they are not operating at full load, they could be used to produce a certain amount of hydrogen, avoiding the costly installation of new IGCC units for hydrogen production. The same goes for the massive introduction of renewable energies (especially wind), possibly generating excess electricity from time to time, which could then perhaps be used to produce hydrogen electrolytically. However, although contra-intuitive, the interaction between both 'systems' turns out to be almost negligible. Firstly, it is shown that it is more beneficial to use IGCC facilities to produce hydrogen with, rather than (excess) wind-generated electricity due to the necessary electrolyser investment costs. But even flexible IGCC facilities do not seem to contribute substantially to the early development of a hydrogen economy. Namely, in most scenarios - which are combinations of a wide range of fuel prices and carbon taxes - one primary-energy carrier (natural gas or coal) seems to be dominant, pushing the other, and the corresponding technologies such as reformers or IGCCs, out of the market. (author)

Comparison of the renewable transportation fuels, liquid hydrogen and methanol, with gasoline - energetic and economic aspects

International Nuclear Information System (INIS)

Specht, M.; Staiss, F.; Bandi, A.; Weimer, T.

1998-01-01

In this paper, the renewable energy vectors liquid hydrogen (LH 2 ) and methanol generated from atmospheric CO 2 are compared with the conventional crude oil-gasoline system. Both renewable concepts, liquid hydrogen and methanol, lead to a drastic CO 2 reduction compared to the fossil-based system. The comparison between the LH 2 and methanol vector for the transport sector shows nearly the same fuel cost and energy efficiency but strong infrastructure advantages for methanol. (author)

Resource Assessment for Hydrogen Production: Hydrogen Production Potential from Fossil and Renewable Energy Resources

Energy Technology Data Exchange (ETDEWEB)

Melaina, M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Penev, M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Heimiller, D. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2013-09-01

This study examines the energy resources required to produce 4-10 million metric tonnes of domestic, low-carbon hydrogen in order to fuel approximately 20-50 million fuel cell electric vehicles. These projected energy resource requirements are compared to current consumption levels, projected 2040 business as usual consumptions levels, and projected 2040 consumption levels within a carbonconstrained future for the following energy resources: coal (assuming carbon capture and storage), natural gas, nuclear (uranium), biomass, wind (on- and offshore), and solar (photovoltaics and concentrating solar power). The analysis framework builds upon previous analysis results estimating hydrogen production potentials and drawing comparisons with economy-wide resource production projections

Renewable energy and low carbon economy transition in India

DEFF Research Database (Denmark)

Shukla, P.R.; Dhar, Subash; Fujino, Junichi

2010-01-01

that aligns India’s emissions to an optimal 450 ppmv CO2-eq. stabilization global response. The second emissions pathway assumes an underlying sustainable development pattern. A low carbon future will be good for renewable energy under both the development pathways, though the share of renewable energy...

Wave power integration with a renewable hydrogen energy system. Paper no. IGEC-1-085

International Nuclear Information System (INIS)

St. Germain, L.; Wild, P.; Rowe, A.

2005-01-01

In British Columbia, approximately 90% of the electricity generated comes from hydroelectric facilities while another abundant and renewable resource, ocean wave energy, is not being utilized at all. Technologies exist that can capture and convert wave energy but there are few studies examining systemic integration of wave energy devices. This work examines the potential to use wave energy as an input into a hydrogen-based renewable energy system. A model of an oscillating water column (OWC) was developed as a module within TRNSYS where it can be coupled to other existing hydrogen-specific components such as an electrolyser, storage device, and fuel cell. The OWC model accounts for device geometry, dynamics, and generator efficiency. For this particular study, wave profiles generated from hourly average data for a location on the west coast of Vancouver Island are used as a resource input. An analysis of the potential to utilise wave energy is carried out with an emphasis on overall system efficiency and resulting device scaling. The results of the integration of wave energy with other renewable energy inputs into a hydrogen-based system are used to make recommendations regarding technical feasibility of wave power projects on Vancouver Island. (author)

Bridging the European Wind Energy Market and a Future Renewable Hydrogen-Inclusive Economy. A Dynamic Techno-economic Assessment

International Nuclear Information System (INIS)

Shaw, S.; Peteves, S.D.

2006-01-01

The study establishes the link between the growing wind market and the emerging hydrogen market of the European Union, in a so-called 'wind-hydrogen strategy'. It considers specifically the diversion of wind electricity, as a wind power control mechanism in high wind penetration situations, for the production of renewable electrolytic hydrogen - a potentially important component of a renewable hydrogen-inclusive economy. The analysis examines the long-term competitiveness of a wind-hydrogen strategy via cost-benefit assessment. It indicates the duration and extent to which (financial) support, if any, would need to be provided in support of such a strategy, and the influence over time of certain key factors on the outcome

Carbon strategy and management in the hydrogen economy

International Nuclear Information System (INIS)

Snyder, C.

2006-01-01

Greenhouse gas (carbon) emission reduction related to the beneficial use of hydrogen is an important aspect in the development and public acceptance of a greater role for hydrogen in the economy. This presentation is an overview of potential effects of the evolving regulatory framework for carbon emissions management in Canada on hydrogen infrastructure development and compare it with activities in other jurisdictions

Modelling hydrogen permeation in a hydrogen effusion probe for monitoring corrosion of carbon steels

International Nuclear Information System (INIS)

Santiwiparat, P.; Rirksomboon, T.; Steward, F.R.; Lister, D.H.; Cook, W.G.

2015-01-01

Hydrogen accumulation inside carbon steel and stainless steel devices shaped like cylindrical cups attached to a pipe containing hydrogen gas was modelled with MATLAB software. Hydrogen transfer around the bottom of the cups (edge effect) and diffusion through the cup walls (material effect) were accounted for. The variation of hydrogen pressure with time was similar for both materials, but the hydrogen plateau pressures in stainless steel cups were significantly higher than those in carbon steel cups. The geometry of the cup also affected the plateau pressure inside the cup. (author)

Hydrogen adsorption in doped porous carbons

International Nuclear Information System (INIS)

L Balan; L Duclaux; S Los

2005-01-01

Full text of publication follows: Hydrogen is a clean fuel that will be used in automotive transport when the problem of storage will be solved. The difficulties of H 2 storage (available space, security and performance, etc...) require a material that can store 5 weight % of hydrogen. Research is focused on new materials that can assume the constraints imposed by the automotive applications. Among these materials, the nano-structured carbons (nano-fibers and single walled carbon nano-tubes) were claimed to be promising by numerous authors [1-3]. The more promising carbon materials for hydrogen adsorption are those having micropores (i. e. single walled carbon nano-tubes and activated carbon), for which the energy of sorption of hydrogen molecules is theoretically higher [7-8]. Presently, the best performance of hydrogen adsorption was found in super-activated microporous carbons sorbing 5 weight % at 77 K, and almost 0.5 % at room temperature and 6 MPa [9]. Up to now, the performance of these materials can still be improved as the known mechanism of sorption in these carbon materials: physi-sorption controlled by Van der Waals attractive forces through London interaction is efficient at cryogenic temperatures (77 K) where the interaction between adsorbent and adsorbate becomes stronger. One way to improve the attractive interaction between adsorbent and molecule is to increase the forces due to the interaction of electrical field and induced dipole of the molecule. This can be theoretically tailored in carbon materials through the electron charge transfer by electron donors who can provide an increase in the electrical field at the surface of the adsorbent. Then, the doping of carbon substrates, appearing to be a promising method to increase the energy of adsorption has been proposed in recent papers as a solution to obtain good hydrogen adsorption properties at appropriate temperatures close to room temperatures [10-12]. Thus, we have studied the adsorption

Hydrogen adsorption in doped porous carbons

International Nuclear Information System (INIS)

Balan, L.; Duchaux, L.; Los, S.

2005-01-01

Full text of publication follows: Hydrogen is a clean fuel that will be used in automotive transport when the problem of storage will be solved. The difficulties of H 2 storage (available space, security and performance, etc...) require a material that can store 5 weight % of hydrogen. Research is focused on new materials that can assume the constraints imposed by the automotive applications. Among these materials, the nano-structured carbons (nano-fibers and single walled carbon nano-tubes) were claimed to be promising by numerous authors [1-3]. The more promising carbon materials for hydrogen adsorption are those having micropores (i. e. single walled carbon nano-tubes and activated carbon), for which the energy of sorption of hydrogen molecules is theoretically higher [7- 8]. Presently, the best performance of hydrogen adsorption was found in super-activated micro-porous carbons sorbing 5 weight % at 77 K, and almost 0.5 % at room temperature and 6 MPa [9]. Up to now, the performance of these materials can still be improved as the known mechanism of sorption in these carbon materials: physisorption controlled by Van der Waals attractive forces through London interaction is efficient at cryogenic temperatures (77 K) where the interaction between adsorbent and adsorbate becomes stronger. One way to improve the attractive interaction between adsorbent and molecule is to increase the forces due to the interaction of electrical field and induced dipole of the molecule. This can be theoretically tailored in carbon materials through the electron charge transfer by electron donors who can provide an increase in the electrical field al the surface of the adsorbent. Then, the doping of carbon substrates, appearing to be a promising method to increase the energy of adsorption has been proposed in recent papers as a solution to obtain good hydrogen adsorption properties at appropriate temperatures close to room temperatures [10-12]. Thus, we have studied the adsorption

Carbon neutral and flexible underground storage of renewable excess energy; Klimaneutrale Flexibilisierung regenerativer Ueberschussenergie mit Untergrundspeichern

Energy Technology Data Exchange (ETDEWEB)

Kuehn, Michael; Nakatem, Natalie; Streibel, Martin; Kempka, Thomas [GeoForschungsZentrum Potsdam (Germany)

2013-10-15

We present an innovative, extended and carbon neutral 'Power-to-Gas-to-Power' concept. Excess electricity from wind and sun can be transformed into hydrogen and with carbon dioxide subsequently into methane. When needed, electricity is regained in a combined cycle plant burning the methane. To close the carbon cycle carbon dioxide is captured on site. Two subsurface storage formations for both gases are required for the technology. Our regional showcase of two German cities, Potsdam and Brandenburg/Havel, demonstrates that about 30% of their electricity demand can be provided in that way, using 17.2% of renewable electricity generated in the State of Brandenburg. We calculate the overall efficiency of the system with 27.7% and the associated costs of electricity are 20,43 Euro-cent/ kWh. Compared to pump storage hydro power and compressed air storage the determined efficiency is worse, however the costs of electricity are competitive. (orig.)

Hydrogen based global renewable energy network

Energy Technology Data Exchange (ETDEWEB)

Akai, Makoto [Mechanical Engineering Laboratory, AIST, MITI, Namiki, Tsukuba (Japan)

1993-12-31

In the last quarter of this century, global environmental problem has emerged as a major scientific, political and social issue. Specific Problems include: depletion of ozone layer by chlorofluorocarbons (CFCs), acid rain, destruction of tropical forests and desertification, pollution of the sea and global wanning due to the greenhouse effect by carbon dioxide and others. Among these problems, particular attention of the world has been focused on the global warming because it has direct linkage to energy consumption which our economic development depends on so far. On the other hand, the future program of The Sunshine Project for alternative energy technology R&D, The Moonlight Project for energy conservation technology R&D, and The Global Environmental Technology Program for environmental problem mitigating technology R&D which are Japan`s national projects being promoted by their Agency of Industrial Science and Technology (AIST) in the Ministry of International Trade and Industry have been reexamined in view of recent changes in the situations surrounding new energy technology. In this regard, The New Sunshine Program will be established by integrating these three activities to accelerate R&D in the field of energy and environmental technologies. In the reexamination, additional stress has been laid on the contribution to solving global environmental problem through development of clean renewable energies which constitute a major part of the {open_quotes}New Earth 21{close_quotes}, a comprehensive, long-term and international cooperative program proposed by MITI. The present paper discusses the results of feasibility study on hydrogen energy system leading to the concept of WE-NET following a brief summary on R&D status on solar and wind energy in Japan.

Hydrogen storage using microporous carbon materials

International Nuclear Information System (INIS)

Buczek, B.; Wolak, E.

2005-01-01

higher temperatures than liquefaction [3]. Last years have brought the interest in hydrogen storage in porous carbon materials, caused by the design and accessibility of new materials, such as fullerenes, carbon nano-tubes and nano-fibers. In particular the tubular carbon structures are perspective highly adsorbing materials, for their surface adsorption (on the internal and external surface of the nano-tubes), and for the effect of capillary condensation [4]. Data presented in Table 1 show that the amount of hydrogen adsorbed on these new materials depends of their modification and on the type of carbon precursor [5]. In this work the concept of hydrogen storage by adsorption was analyzed. The discussion is based on measurements of hydrogen adsorption on commercial active carbon in the temperature range 77 - 298 K at pressures up to 4 MPa. The amount of gas that can be stored in an adsorption system depends on the adsorbent characteristics and the operating conditions. Adsorption method was compared with another one taking into account both technical and economical aspects. The results show that the adsorption technique could provide a viable method for hydrogen storage. [1]G. D. Berry, A. D. Pastemak, G. D. Rambach, J. R. Smith, N. Schock, Energy. 21, 289, 1996; [2]L. Czepirski, Przem. Chem. 70, 129, 1991 (in Polish); [3]B. Buczek, L. Czepirski, Inz. Chem. Proc., 24, 545, 2003; [4]U. Huczko, Przem. Chem. 81, 19, 2002 (in Polish); [5]U. Buenger, W. Zittel, Appl. Phys. A 72, 147, 2001. (authors)

Preparation of activated carbon from a renewable agricultural ...

African Journals Online (AJOL)

STORAGESEVER

2010-05-10

May 10, 2010 ... good and cheap agricultural residue for the production of activated carbon, with carbon, hydrogen and nitrogen ... fuel-wood because household energy requirements are met with ..... Thin layer solar drying and mathematical.

Renewable energy carriers: Hydrogen or liquid air/nitrogen?

International Nuclear Information System (INIS)

Li Yongliang; Chen Haisheng; Zhang Xinjing; Tan Chunqing; Ding Yulong

2010-01-01

The world's energy demand is met mainly by the fossil fuels today. The use of such fuels, however, causes serious environmental issues, including global warming, ozone layer depletion and acid rains. A sustainable solution to the issues is to replace the fossil fuels with renewable ones. Implementing such a solution, however, requires overcoming a number of technological barriers including low energy density, intermittent supply and mobility of the renewable energy sources. A potential approach to overcoming these barriers is to use an appropriate energy carrier, which can store, transport and distribute energy. The work to be reported in this paper aims to assess and compare a chemical energy carrier, hydrogen, with a physical energy carrier, liquid air/nitrogen, and discuss potential applications of the physical carrier. The ocean energy is used as an example of the renewable energy sources in the work. The assessment and comparison are carried out in terms of the overall efficiency, including production, storage/transportation and energy extraction. The environmental impact, waste heat recovery and safety issues are also considered. It is found that the physical energy carrier may be a better alternative to the chemical energy carrier under some circumstances, particularly when there are waste heat sources.

Thermodynamics and vibrational study of hydrogenated carbon nanotubes: A DFT study

Science.gov (United States)

Khalil, Rana M. Arif; Hussain, Fayyaz; Rana, Anwar Manzoor; Imran, Muhammad

2018-02-01

Thermodynamic stability of the hydrogenated carbon nanotubes has been explored in the chemisorption limit. Statistical physics and density functional theory calculations have been used to predict hydrogen release temperatures at standard pressure in zigzag and armchair carbon nanotubes. It is found that hydrogen release temperatures decrease with increase in diameters of hydrogenated zigzag carbon nanotubes (CNTs) but opposite trend is noted in armchair CNTs at standard pressure of 1 bar. The smaller diameter hydrogenated zigzag CNTs have large values of hydrogen release temperature due to the stability of Csbnd H bonds. The vibrational density of states for hydrogenated carbon nanotubes have been calculated to confirm the Csbnd H stretching mode caused by sp3 hybridization.

Renewable Hydrogen Carrier - Carbohydrate: Constructing the Carbon-Neutral Carbohydrate Economy

Science.gov (United States)

2011-01-31

combinations have been investigated for the production of hydrogen from biomass carbohydrate. Chemical catalysis approaches include pyrolysis [19...temperature. High fructose corn syrup, low-cost sucrose replacement, is made by stabilized glucose isomerase, which can work at ~60 °C for even about two...gasoline, vegetable oil vs. biodiesel, corn kernels vs. ethanol [31,109]. Given a price of $0.18/kg carbohydrate (i.e., $10.6/GJ) [2,44], the hydrogen

Optimal production of renewable hydrogen based on an efficient energy management strategy

International Nuclear Information System (INIS)

Ziogou, Chrysovalantou; Ipsakis, Dimitris; Seferlis, Panos; Bezergianni, Stella; Papadopoulou, Simira; Voutetakis, Spyros

2013-01-01

This work presents the development of a flexible energy management strategy (EMS) for a renewable hydrogen production unit through water electrolysis with solar power. The electricity flow of the unit is controlled by a smart microgrid and the overall unattended operation is achieved by a supervisory control system. The proposed approach formalizes the knowledge regarding the system operation using a finite-state machine (FSM) which is subsequently combined with a propositional-based logic to describe the transitions among various process states. The operating rules for the integrated system are derived by taking into account both the operating constraints and the interaction effects among the individual subsystems in a systematic way. Optimal control system parameter values are obtained so that a system performance criterion incorporating efficient and economic operation is satisfied. The resulted EMS has been deployed to the industrial automation system that monitors and controls a small-scale experimental solar hydrogen production unit. The overall performance of the proposed EMS in the experimental unit has been evaluated over short-term and long-term operating periods resulting in smooth and efficient hydrogen production. - Highlights: • Development of an energy management strategy based on a finite-state machine and propositional-based reasoning. • Deployment of the energy-aware algorithm to an autonomous renewable hydrogen production unit. • Supervisory control of the electricity flow by a smart microgrid using an industrial automation system. • Unattended operation and remote monitoring incorporating subsystem interactions in a systematic way. • Optimal hydrogen production regardless of the weather conditions through water electrolysis with solar power

Renewable energies development: what contribution of the carbon market?

International Nuclear Information System (INIS)

Bordier, Cecile

2008-12-01

In the climate-energy package, the European Union has committed to achieve objectives differentiated by countries to reduce greenhouse gas emissions and developing renewable energies. Part of the emissions reduction must be achieved through a common mechanism to all Member States: the European CO 2 trading market (EU ETS) covers about 40% of emissions of gas European greenhouse from five major industrial sectors, including power generation. The development of renewable energy is the responsibility of each member state. To meet its commitments in terms of renewable energy, each Member State may adopt economic incentives: tendering, purchase prices or green certificates. This Climate Report describes two national policies with different instruments: aid mechanism by prices in France and definition of quantitative targets in the UK. The author attempts to evaluate these policies for the production of renewable electricity in terms of cost per ton of carbon avoided to compare with the price of carbon quotas in the EU ETS. The results show that the cost of national incentive policies for renewable energy per ton of CO 2 avoided varies significantly from one country to another, but in both cases higher than the quota price on the European market. It is difficult to draw definitive conclusions on economic effectiveness of different policy instruments. The first phase of the European exchange of CO 2 quotas market has induced a stress relatively low, weighing mainly on the electricity generation sector. The allocations to the electricity sector have been reduced from 2008 and quotas will be auctioned from 2013 within the limits of an overall ceiling will decrease year by year. This increase in stress on emissions should play a key role in the deployment of CO 2 emission reduction solutions in this sector, including the development of renewable energies. The incentive mechanisms at the national level could complement the impact of the European carbon market by accelerating

Valorization of Renewable Carbon Resources for Chemicals.

Science.gov (United States)

Chen, Xi; Zhang, Bin; Wang, Yunzhu; Yan, Ning

2015-01-01

The overuse of fossil fuels has caused an energy crisis and associated environment issues. It is desirable to utilize renewable resources for the production of chemicals. This review mainly introduces our recent work on the transformation of renewable carbon resources including the conversion of cellulose, lignin, and chitin into sustainable chemicals. Various transformation routes have been established to form value-added chemicals, and accordingly a variety of effective catalytic systems have been developed, either based on metal catalysis and/or acid-base catalysis, to enable the desired transformation.

Financing renewable energy infrastructure: Formulation, pricing and impact of a carbon revenue bond

International Nuclear Information System (INIS)

Tang, Amy; Chiara, Nicola; Taylor, John E.

2012-01-01

Renewable energy systems depend on large financial incentives to compete with conventional generation methods. Market-based incentives, including state-level REC markets and international carbon markets have been proposed as solutions to increase renewable energy investment. In this paper we introduce and formulate a carbon revenue bond, a financing tool to complement environmental credit markets to encourage renewable energy investment. To illustrate its use, we value the bond by predicting future revenue using stochastic processes after analyzing historical price data. Three illustrative examples are presented for renewable energy development in three different markets: Europe, Australia and New Jersey. Our findings reveal that the sale of a carbon revenue bond with a ten year maturity can finance a significant portion of a project's initial cost. - Highlights: ► Current financial incentives for renewable energy in the US are inadequate. ► We introduce and structure a “carbon revenue bond” as an innovative financing tool. ► Stochastic models of environmental credit prices are used to illustrate bond pricing. ► Three examples illustrate revenue bond impact on initial cost of infrastructure.

Carbon material for hydrogen storage

Science.gov (United States)

Bourlinos, Athanasios; Steriotis, Theodore; Stubos, Athanasios; Miller, Michael A

2016-09-13

The present invention relates to carbon based materials that are employed for hydrogen storage applications. The material may be described as the pyrolysis product of a molecular precursor such as a cyclic quinone compound. The pyrolysis product may then be combined with selected transition metal atoms which may be in nanoparticulate form, where the metals may be dispersed on the material surface. Such product may then provide for the reversible storage of hydrogen. The metallic nanoparticles may also be combined with a second metal as an alloy to further improve hydrogen storage performance.

Hydrogenation of carbon monoxide over supported palladium catalysts

Energy Technology Data Exchange (ETDEWEB)

Fujimoto, K.; Hashimoto, H.; Kunugi, T.

1978-03-01

An alumina-supported 2% palladium catalyst had higher activity for carbon monoxide hydrogenation than a silica-supported 2% palladium catalyst, at 250/sup 0/-400/sup 0/C and 1 atm. The addition of lanthanum oxide or thorium oxide, but not of potassium oxide, to the silica-supported catalyst increased the conversion at 350/sup 0/C from 1.1% to 81.0% with a selectivity of 56.1% for methane, 1.4% for C/sub 2/ compounds, 0.1% for C/sub 3/ compounds, and 42.5% for carbon dioxide. Temperature-programed desorption of carbon monoxide in a hydrogen stream showed that of two desorption peaks observed for carbon monoxide, the one at higher temperature corresponded to the carbon monoxide species which hydrogenates to methane and that the area of this peak increased with increasing thorium content of the catalyst. Graphs, tables, and 12 references.

Energy modeling and analysis for optimal grid integration of large-scale variable renewables using hydrogen storage in Japan

International Nuclear Information System (INIS)

Komiyama, Ryoichi; Otsuki, Takashi; Fujii, Yasumasa

2015-01-01

Although the extensive introduction of VRs (variable renewables) will play an essential role to resolve energy and environmental issues in Japan after the Fukushima nuclear accident, its large-scale integration would pose a technical challenge in the grid management; as one of technical countermeasures, hydrogen storage receives much attention, as well as rechargeable battery, for controlling the intermittency of VR power output. For properly planning renewable energy policies, energy system modeling is important to quantify and qualitatively understand its potential benefits and impacts. This paper analyzes the optimal grid integration of large-scale VRs using hydrogen storage in Japan by developing a high time-resolution optimal power generation mix model. Simulation results suggest that the installation of hydrogen storage is promoted by both its cost reduction and CO 2 regulation policy. In addition, hydrogen storage turns out to be suitable for storing VR energy in a long period of time. Finally, through a sensitivity analysis of rechargeable battery cost, hydrogen storage is economically competitive with rechargeable battery; the cost of both technologies should be more elaborately recognized for formulating effective energy policies to integrate massive VRs into the country's power system in an economical manner. - Highlights: • Authors analyze hydrogen storage coupled with VRs (variable renewables). • Simulation analysis is done by developing an optimal power generation mix model. • Hydrogen storage installation is promoted by its cost decline and CO 2 regulation. • Hydrogen storage is suitable for storing VR energy in a long period of time. • Hydrogen storage is economically competitive with rechargeable battery

Nickel foam/polyaniline-based carbon/palladium composite electrodes for hydrogen storage

International Nuclear Information System (INIS)

Skowronski, Jan M.; Urbaniak, Jan

2008-01-01

The sandwich-like nickel/palladium/carbon electrodes exhibiting ability to absorb hydrogen in alkaline solution are presented. Electrodes were prepared by successive deposition of palladium and polyaniline layers on nickel foam substrate followed by heat treatment to give Ni/Pd/C electrode. It was shown that thermal conversion of polymer into carbon layer and subsequent thermal activation of carbon component bring about the modification of the mechanism of reversible hydrogen sorption. It was proven that carbon layer, interacting with Pd catalyst, plays a considerable role in the process of hydrogen storage. In the other series of experiments, Pd particles were dispersed electrochemically on carbon coating leading to Ni/C/Pd system. The adding of the next carbon layer resulted in Ni/C/Pd/C electrodes. Electrochemical properties of the electrodes depend on both the sequence of Pd and C layers and the preparation/activation of carbon coating. Electrochemical behavior of sandwich-like electrodes in the reaction of hydrogen sorption/desorption was characterized in 6 M KOH using the cyclic voltammetry method and the results obtained were compared to those for Ni/Pd electrode. The anodic desorption of hydrogen from electrodes free and containing carbon layer was considered after the potentiodynamic as well as potentiostatic sorption of hydrogen. The influence of the sorption potential and the time of rest of electrodes at a cut-off circuit on the kinetics of hydrogen recovery were examined. The results obtained for Ni/Pd/C electrodes indicate that the displacement of hydrogen between C and Pd phase takes place during the rest at a cut-off circuit. Electrodes containing carbon layer require longer time for hydrogen electrosorption. On the other hand, the presence of carbon layer in electrodes is advantageous because a considerable longer retention of hydrogen is possible, as compared to Pd/Ni electrode. Hydrogen stored in sandwich-like electrodes can instantly be

A study on hydrogen storage through adsorption in nano-structured carbons; Etude du stockage d'hydrogene par adsorption dans des carbones nanostructures

Energy Technology Data Exchange (ETDEWEB)

Langohr, D

2004-10-15

The aim of this work is to build and calibrate an experimental set-up for the testing of the materials, to produce some carbon materials in large amounts and characterise them, and finally, to test these materials in their ability to store hydrogen. This will help in establishing a link between the hydrogen storage capacities of the carbons and their nano-structure. The script is divided into four chapters. The first chapter will deal with the literature review on the thematic of hydrogen storage through adsorption in the carbon materials, while the second chapter will present the experimental set-up elaborated in the laboratory. The third chapter explains the processes used to produce the two families of carbon materials and finally, the last chapter presents the structural characterisation of the samples as well as the experimental results of hydrogen storage on the materials elaborated. (author)

Decoration of carbon nano surfaces with hydrogen and hydrogen rich molecules

International Nuclear Information System (INIS)

Zöttl, S.

2013-01-01

The use of helium nano droplets as a matrix to investigate different atomic and molecular samples is a well established experimental technique. The unique properties of helium allow for different analytical methods and at the same time provide a stable ambient temperature. Cluster growth inside helium nano droplets can be accomplished by repeatedly doping the droplets with sample particles in a controlled environment. The experimental work represented in this thesis was performed using helium nano droplets to create clusters of fullerenes like C 60 and C 70 . The adsorption properties of these fullerene clusters regarding hydrogen and hydrogen rich molecules have been subject to investigation. The observed results suggest that curved carbon nano surfaces offer higher storage densities than planar graphite surfaces. The use of C 60 as a model carbon nano structure provides a well understood molecule for testing and evaluating computational methods to calculate surface properties of various carbon nano materials. The cost effective storage of hydrogen for mobile applications plays a key role in the development of alternatives to fossil fuels. For that reason, the application of carbon nano materials to store hydrogen by adsorption has attracted much scientific attention lately. The insights gained in the presented thesis contribute to the collective efforts and deliver more refined tools to estimate the adsorption properties of future carbon nano materials. In addition to the aforementioned, a time-of-flight mass spectrometer for educational purpose has been designed and constructed in the framework of my PhD thesis. The instrument is successfully used in various lab courses and information on the setup can be found in the Appendix of this work. (author) [de

Carbon finance options in renewable energy

International Nuclear Information System (INIS)

Nahar, P.

2010-01-01

The Kyoto Protocol splits the world into two categories, notably Annex 1 with binding targets; and non-Annex 1 without any binding targets. This presentation discussed the Kyoto Protocol, with particular reference to the flexibility mechanisms which allow countries to achieve their emission targets in a cost effective way through emission trading, joint implementation, or clean development mechanisms (CDM). The CDM was outlined in detail in terms of how it works. The CDM key concepts include baseline use, additionality, and monitoring. Reasons for risk and CDM renewable energy projects were also outlined. Other topics that were presented included the impact of carbon finance; United States federal climate policy; European Union policy; EVO structured carbon; portfolio management; and EVO structured carbon. tabs., figs.

Nuclear energy and its synergies with renewable energies

International Nuclear Information System (INIS)

Carre, F.; Mermilliod, N.; Devezeaux De Lavergne, J.G.; Durand, S.

2011-01-01

France has the ambition to become a world leader in both nuclear industry and in renewable energies. 3 types of synergies between nuclear power and renewable energies are highlighted. First, nuclear power can be used as a low-carbon energy to produce the equipment required to renewable energy production for instance photovoltaic cells. Secondly, to benefit from the complementary features of both energies: continuous/intermittency of the production, centralized/local production. The future development of smart grids will help to do that. Thirdly, to use nuclear energy to produce massively hydrogen from water and synthetic fuels from biomass. (A.C.)

Chemical storage of wind energy by renewable methanol production: Feasibility analysis using a multi-criteria decision matrix

International Nuclear Information System (INIS)

Matzen, Michael; Alhajji, Mahdi; Demirel, Yaşar

2015-01-01

This study is for the technoeconomic analysis of an integral facility consisting of wind energy-based electrolytic hydrogen production, bioethanol-based carbon dioxide capture and compression, and direct methanol synthesis. ASPEN Plus was used to simulate the facility producing 97.01 mt (metric tons) methanol/day using 138.37 mt CO_2/day and 18.56 mt H_2/day. A discounted cash flow diagram for the integral facility is used for the economic analysis at various hydrogen production costs and methanol selling prices. The feasibility analysis is based on a multi-criteria decision matrix consisting of economic and sustainability indicators comparing renewable and non-renewable methanol productions. The overall energy efficiency for the renewable methanol is around 58%. Fixation of carbon reduces the CO_2 equivalent emission by around −1.05 CO_2e/kg methanol. The electrolytic hydrogen production cost is the largest contributor to the economics of the integral facility. The feasibility analysis based on multi-criteria shows that renewable methanol production may be feasible. - Highlights: • We simulate renewable methanol production from wind-based hydrogen and CO_2_. • Methanol production can fix 1.05 kg CO_2/kg methanol with an energy efficiency of 58%. • Economic and sustainability metrics are estimated for the integral facility. • We introduce a decision matrix with both economic and sustainability indicators. • Renewable methanol may be feasible versus conventional fossil fuel-based methanol.

Hydrogen generator characteristics for storage of renewably-generated energy

International Nuclear Information System (INIS)

Kotowicz, Janusz; Bartela, Łukasz; Węcel, Daniel; Dubiel, Klaudia

2017-01-01

The paper presents a methodology for determining the efficiency of a hydrogen generator taking the power requirements of its auxiliary systems into account. Authors present results of laboratory experiments conducted on a hydrogen generator containing a PEM water electrolyzer for a wide range of device loads. On the basis of measurements, the efficiency characteristics of electrolyzers were determined, including that of an entire hydrogen generator using a monitored power supply for its auxiliary devices. Based on the results of the experimental tests, the authors have proposed generalized characteristics of hydrogen generator efficiency. These characteristics were used for analyses of a Power-to-Gas system cooperating with a 40 MW wind farm with a known yearly power distribution. It was assumed that nightly-produced hydrogen is injected into the natural gas transmission system. An algorithm for determining the thermodynamic and economic characteristics of a Power-to-Gas installation is proposed. These characteristics were determined as a function of the degree of storage of the energy produced in a Renewable Energy Sources (RES) installation, defined as the ratio of the amount of electricity directed to storage to the annual amount of electricity generated in the RES installation. Depending on the degree of storage, several quantities were determined. - Highlights: • The efficiency characteristics of PEM electrolyzer are determined. • Generalized characteristics of hydrogen generator efficiency are proposed. • Method of choice of electrolyser nominal power for Power-to-Gas system was proposed. • Development of Power-to-Gas systems requires implementation of support mechanisms.

Modification of single wall carbon nanotubes (SWNT) for hydrogen storage

Energy Technology Data Exchange (ETDEWEB)

Rashidi, A.M.; Nouralishahi, A.; Karimi, A.; Kashefi, K. [Nanotechnology Research Center, Research Institute of petroleum industry (RIPI), Tehran (Iran); Khodadadi, A.A.; Mortazavi, Y. [Chemical engineering Department, University of Tehran, Tehran (Iran)

2010-09-15

Due to unique structural, mechanical and electrical properties of single wall carbon nanotubes, SWNTs, they have been proposed as promising hydrogen storage materials especially in automotive industries. This research deals with investing of CNT's and some activated carbons hydrogen storage capacity. The CNT's were prepared through natural gas decomposition at a temperature of 900 C over cobalt-molybdenum nanoparticles supported by nanoporous magnesium oxide (Co-Mo/MgO) during a chemical vapor deposition (CVD) process. The effects of purity of CNT (80-95%wt.) on hydrogen storage were investigated here. The results showed an improvement in the hydrogen adsorption capacity with increasing the purity of CNT's. Maximum adsorption capacity was 0.8%wt. in case of CNT's with 95% purity and it may be raised up with some purification to 1%wt. which was far less than the target specified by DOE (6.5%wt.). Also some activated carbons were manufactured and the results compared to CNTs. There were no considerable H{sub 2}-storage for carbon nanotubes and activated carbons at room-temperature due to insufficient binding between H{sub 2} molecules carbon nanostructures. Therefore, hydrogen must be adsorbed via interaction of atomic hydrogen with the storage environment in order to achieve DOE target, because the H atoms have a very stronger interaction with carbon nanostructures. (author)

Carbon compound used in hydrogen storage; Compuesto de carbon utilizado en almacenamiento de hidrogeno

Energy Technology Data Exchange (ETDEWEB)

Iturbe G, J L; Lopez M, B E [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

2004-07-01

In the present work it is studied the activated carbon of mineral origin for the sorption of hydrogen. The carbon decreased of particle size by means of the one alloyed mechanical. The time of mill was of 10 hours. The characterization one carries out by scanning electron microscopy and X-ray diffraction. The hydrogen sipped in the carbon material it was determined using the Thermal gravimetric method (TGA). The conditions of hydrogenation went at 10 atm of pressure and ambient temperature during 18 hours. They were also carried out absorption/desorption cycles of hydrogen in the same one system of thermal gravimetric analysis. The results showed percentages of sorption of 2% approximately in the cycles carried out in the system TGA and of 4.5% in weight of hydrogen at pressure of 10 atmospheres and ambient temperature during 18 hours. (Author)

Sequestration of carbon dioxide with hydrogen to useful products

Energy Technology Data Exchange (ETDEWEB)

Adams, Michael W. W.; Kelly, Robert M.; Hawkins, Aaron B.; Menon, Angeli Lal; Lipscomb, Gina Lynette Pries; Schut, Gerrit Jan

2017-03-07

Provided herein are genetically engineered microbes that include at least a portion of a carbon fixation pathway, and in one embodiment, use molecular hydrogen to drive carbon dioxide fixation. In one embodiment, the genetically engineered microbe is modified to convert acetyl CoA, molecular hydrogen, and carbon dioxide to 3-hydroxypropionate, 4-hydroxybutyrate, acetyl CoA, or the combination thereof at levels greater than a control microbe. Other products may also be produced. Also provided herein are cell free compositions that convert acetyl CoA, molecular hydrogen, and carbon dioxide to 3-hydroxypropionate, 4-hydroxybutyrate, acetyl CoA, or the combination thereof. Also provided herein are methods of using the genetically engineered microbes and the cell free compositions.

Carbon Emissions, Renewable Electricity, and Profits: Comparing Policies to Promote Anaerobic Digesters on Dairies

OpenAIRE

Key, Nigel D.; Sneeringer, Stacy E.

2012-01-01

Anaerobic digesters can provide renewable energy and reduce greenhouse gas emissions from manure management. Government policies that encourage digester adoption by livestock operations include construction cost-share grants, renewable electricity subsidies, and carbon pricing (offset) programs. However, the effectiveness and efficiency of these policies is not well understood. For the U.S. dairy sector, we compare predicted digester adoption rates, carbon emission reductions, renewable elect...

Hydrogenation of surface carbon on alumina-supported nickel

Energy Technology Data Exchange (ETDEWEB)

Mccarthy, J.G.; Wise, H.

1979-05-01

The methanation of carbon deposited by CO or ethylene decomposition on Girdler G-65 catalyst (25Vertical Bar3< nickel, 8Vertical Bar3< alkali, mostly CaO, 4Vertical Bar3< C as graphite, on alumina) was studied by temperature-programed desorption and temperature-programed surface reaction. Four types of carbon were identified: ..cap alpha..-carbon consisted of isolated carbon atoms bonded to nickel and reacting with hydrogen at 470/sup 0/ +/- 20/sup 0/K; ..gamma..-carbon was probably a bulk carbide, most likely Ni/sub 3/C, which had a reaction peak at 550/sup 0/K; ..beta..-carbon consisted of amorphous, polymerized carbon, which had a reaction peak at 680/sup 0/K; and an unreactive crystalline graphite-like species. The ..cap alpha..-form was thermally unstable and transformed into the ..beta..-form above 600/sup 0/K. Both ..cap alpha..- and ..beta..-forms slowly converted to inert graphite above 600/sup 0/K. The evidence suggested that synthesis gas methanation proceeds by dissociative adsorption of CO as the rate-determining step which forms a very reactive carbon adatom state (..cap alpha..') which converts to the ..cap alpha..-state in the absence of hydrogen and to methane in the presence of hydrogen.

Hydrogen storage in carbon nano-tubes; Stockage d'hydrogene dans les nanotubes de carbone

Energy Technology Data Exchange (ETDEWEB)

Becher, M.; Haluska, M.; Hirscher, M. [Max-Planck-Institut fuer Metallforschung, Stuttgart (Germany); Quintel, A.; Skakalova, V.; Dettlaff-Weglikovska, U.; Chen, X.; Hulman, M.; Choi, Y.; Roth, S.; Meregalli, V.; Parrinello, M. [Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany); Strobel, R.; Jorissen, L. [Zentrum fur Sonnenenergie und Wasserstoff-Forschung, Ulm (Germany); Kappes, M.M. [Karlsruhe Univ., Institut fur Physikalische Chemie(Germany); Fink, J. [Institut fur Festkorper-Und Werkstoffforschun, Dresden (Germany); Zuttel, A. [Fribourg Univ., Dept. Physique (Switzerland); Stepanek, I.; Bernier, P. [Montpellier-2 Univ., GDPC, 34 (France)

2003-11-01

Hydrogen storage in new nano-structured carbonic materials is a topic for lively discussion. The measured storage capacities of these materials, which have been announced in the literature during the last ten years are spread over an enormous range from about 0.1 wt% up to 67 wt%. This paper will give a report on the state of the art of hydrogen storage in carbon nano-structures. We shall critically review the recent 'key publications' on this topic, which claim storage capacities clearly above the technological bench mark set by the US Department of Energy, and we shall report new results which have been obtained in a joint project sponsored by the Federal Ministry for Education and Research in Germany (BMBF). (authors)

Hydrogen storage on carbon materials: state of the art

International Nuclear Information System (INIS)

D Cazorla Amoros; D Lozano Castello; F Suarez Garcia; M Jorda Beneytoa; A Linares Solano

2005-01-01

Full text of publication follows: From an economic point of view, the use of hydrogen could revolutionize energy and transportation markets, what generates a great interest towards this fuel. This interest has led to the so-called 'hydrogen economy'. However, the main drawback for the use of hydrogen as transportation fuel or in power generation is the storage of this gas to reach a sufficiently high energy density, which could fit to the goals of the DOE hydrogen plan to automotive fuel cell systems i.e. 62 kg H 2 /m 3 ). [1] A review of both experimental and theoretical studies published on the field of hydrogen storage on carbon materials (nano-tubes, nano-fibers and porous carbons) shows a large dispersion in hydrogen storage values. Although some values have exceeded by far the goals of the DOE [2], other authors assure that it is not feasible the use of carbonaceous materials as hydrogen storage systems [3]. The first objective of this presentation is to analyze some possible reasons of the large values dispersion. The discrepancy among the different theoretical studies can be due to non-realist models or to unsuitable approaches. High results dispersion and low reproducibility of experimental measurements are mostly consequence of experimental errors (as for example, the use of small amount of sample) and/or to the use of non-purified materials. In fact, the main disadvantage of the use of novel carbon materials, such as nano-tubes and nano-fibers, is the unavailability of large amounts of those materials with sufficient purity in order to get both feasible measurements in the laboratory, an their subsequent use in large scale. In addition to these possible reasons of errors, for a better understanding of the large results dispersion, the different mechanism of hydrogen storage, such as hydride formation, hydrogen transfer and hydrogen adsorption will be also reviewed in this presentation. Differently to nano-tubes and nano-fibers, activated carbons are

A study on hydrogen storage through adsorption in nano-structured carbons; Etude du stockage d'hydrogene par adsorption dans des carbones nanostructures

Energy Technology Data Exchange (ETDEWEB)

Langohr, D

2004-10-15

The aim of this work is to build and calibrate an experimental set-up for the testing of the materials, to produce some carbon materials in large amounts and characterise them, and finally, to test these materials in their ability to store hydrogen. This will help in establishing a link between the hydrogen storage capacities of the carbons and their nano-structure. The script is divided into four chapters. The first chapter will deal with the literature review on the thematic of hydrogen storage through adsorption in the carbon materials, while the second chapter will present the experimental set-up elaborated in the laboratory. The third chapter explains the processes used to produce the two families of carbon materials and finally, the last chapter presents the structural characterisation of the samples as well as the experimental results of hydrogen storage on the materials elaborated. (author)

GAT 4 production and storage of hydrogen. Report July 2004; GAT 4 procduction et stockage de l'hydrogene. Rapport juillet 2004

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-07-01

This paper concerns two aspects of the hydrogen: the production and the storage. For both parts the challenges and a state of the art are presented. It discusses also the hydrogen production by renewable energies, by solar energy, the hydrogen of hydrocarbons reforming purification, active phases development, thermal transfer simulation. Concerning the hydrogen storage the hydrogen adsorption by large surface solid, the storage by metallic hydrides, the alanates and light hydrides, the adsorption on carbon nano-tubes, the storage in nano-structures, the thermal and mechanical simulation of the hydrogen are presented. (A.L.B.)

Mace-like hierarchical MoS2/NiCo2S4 composites supported by carbon fiber paper: An efficient electrocatalyst for the hydrogen evolution reaction

Science.gov (United States)

Sun, Lan; Wang, Tao; Zhang, Long; Sun, Yunjin; Xu, Kewei; Dai, Zhengfei; Ma, Fei

2018-02-01

The rational design and preparation of earth-abundant, stable and efficient electrocatalysts for hydrogen production is currently the subject in extensive scientific and technological researches toward the future of a clean-energy society. Herein, a mace-like MoS2/NiCo2S4 hierarchical structure is designed and synthesized on carbon fiber paper via a facile hydrothermal method, and evaluated as electrocatalyst for hydrogen evolution reaction. In the MoS2/NiCo2S4/carbon fiber paper hierarchical structures, MoS2 nanosheets are dispersively distributed on the surface of NiCo2S4 nanowires, which provides an enlarged surface area, abundant interfaces and catalytic active sites. As for hydrogen evolution reaction, such MoS2/NiCo2S4/carbon fiber paper heterostructures give rise to a hydrogen evolution reaction catalytic current density of 10 mA cm-2 with a lower overpotential of 139 mV and a smaller Tafel slope of 37 mV·dec-1 than those of MoS2/carbon fiber paper and NiCo2S4/carbon fiber paper counterparts, exhibiting a prominent electrocatalytic performance. Moreover, the electrocatalytic properties change little after 5000 CV cycles and continual electrolysis for 12 h without obvious decay, respectively, demonstrating high durability and stability. The excellent hydrogen evolution reaction performances endow the hierarchical configuration MoS2/NiCo2S4/carbon fiber paper with promising alternative in HER and other related renewable energy fields.

Hydrogen storage in engineered carbon nanospaces.

Science.gov (United States)

Burress, Jacob; Kraus, Michael; Beckner, Matt; Cepel, Raina; Suppes, Galen; Wexler, Carlos; Pfeifer, Peter

2009-05-20

It is shown how appropriately engineered nanoporous carbons provide materials for reversible hydrogen storage, based on physisorption, with exceptional storage capacities (approximately 80 g H2/kg carbon, approximately 50 g H2/liter carbon, at 50 bar and 77 K). Nanopores generate high storage capacities (a) by having high surface area to volume ratios, and (b) by hosting deep potential wells through overlapping substrate potentials from opposite pore walls, giving rise to a binding energy nearly twice the binding energy in wide pores. Experimental case studies are presented with surface areas as high as 3100 m(2) g(-1), in which 40% of all surface sites reside in pores of width approximately 0.7 nm and binding energy approximately 9 kJ mol(-1), and 60% of sites in pores of width>1.0 nm and binding energy approximately 5 kJ mol(-1). The findings, including the prevalence of just two distinct binding energies, are in excellent agreement with results from molecular dynamics simulations. It is also shown, from statistical mechanical models, that one can experimentally distinguish between the situation in which molecules do (mobile adsorption) and do not (localized adsorption) move parallel to the surface, how such lateral dynamics affects the hydrogen storage capacity, and how the two situations are controlled by the vibrational frequencies of adsorbed hydrogen molecules parallel and perpendicular to the surface: in the samples presented, adsorption is mobile at 293 K, and localized at 77 K. These findings make a strong case for it being possible to significantly increase hydrogen storage capacities in nanoporous carbons by suitable engineering of the nanopore space.

Determination of contents of carbonate and hydrogen carbonate in solutions for alkaline leading of uranium ores

International Nuclear Information System (INIS)

Radil, V.

1988-01-01

The new analytical method is based on the determination of the molar ratio carbonate - hydrogen carbonate using the measured concentration of hydrogen ions, the determination of the dissociation constant of carbonic acid for different values of ionic strength. The concentration of hydrogen ions was measured with a Metrohm 632 pH meter with the use of a combined glass electrode. The content of total carbonate carbon was determined coulometrically and the uranium content was determined by extraction with tributyl phosphate and by spectrometry of the complex of uranyl ions with Arsenazo III. Model solutions were used for the experiments which contained a high concentration of sulfate ions, thiosulfate ions, uranium and various proportions of carbonate and hydrogen carbonate. The composition of the individual samples of the extraction solutions are tabulated. The calibration was made of the glass combined electrode at different ionic strength, the values determined of dissociation constants of carbonic acid for different ionic strength. The mathematical procedure is described for the calculation of molar concentrations of carbonate and hudrogen carbonate and the results are presented of the analysis of model solutions. (E.S.). 5 tabs., 1 fig., 5 refs

Hydrogen storage on carbon materials: state of the art

International Nuclear Information System (INIS)

Cazorla-Amoros, D.; Lozano-Castello, D.; Suarez-Garcia, F.; Jorda-Beneyto, M.; Linares-Solano, A.

2005-01-01

Complete text of publication follows: From an economic point of view, the use of hydrogen could revolutionize energy and transportation markets, what generates a great interest towards this fuel. This interest has led to the so-called 'hydrogen economy'. However, the main drawback for the use of hydrogen as transportation fuel or in power generation is the storage of this gas to reach a sufficiently high energy density, which could fit to the goals of the DOE hydrogen plan to automotive fuel cell systems i.e. 62 kg H 2 /m 3 ) [1]. A review of both experimental and theoretical studies published on the field of hydrogen storage on carbon materials (nano-tubes, nano-fibers and porous cartons) shows a large dispersion in hydrogen storage values. Although some values have exceeded by far the goals of the DOE [2], other authors assure that it is not feasible the use of carbonaceous materials as hydrogen storage systems [3]. The first objective of this presentation is to analyze some possible reasons of the large values dispersion. The discrepancy among the different theoretical studies can be due to non-realist models or to unsuitable approaches. High results dispersion and low reproducibility of experimental measurements are mostly consequence of experimental errors (as for example, the use of small amount of sample) and/or to the use of non-purified materials. In fact, the main disadvantage of the use of novel carbon materials, such as nano-tubes and nano-fibers, is the unavailability of large amounts of those materials with sufficient purity in order to get both feasible measurements in the laboratory, an their subsequent use in large scale. In addition to these possible reasons of errors, for a better understanding of the large results dispersion, the different mechanism of hydrogen storage, such as hydride formation, hydrogen transfer and hydrogen adsorption will be also reviewed in this presentation. Differently to nano-tubes and nano-fibers, activated carbons are

Prospects for hydrogen in the German energy system

International Nuclear Information System (INIS)

Hake, J.-F.; Linssen, J.; Walbeck, M.

2006-01-01

The focus of the paper concerns the current discussion on the contribution of the hydrogen economy to a 'sustainable energy system'. It considers whether advantages for the environmental situation and energy carrier supply can be expected from the already visible future characteristics of hydrogen as a new secondary energy carrier. Possible production paths for hydrogen from hydrocarbon-based, renewable or carbon-reduced/-free primary energy carriers are evaluated with respect to primary energy use and CO 2 emissions from the fuel cycle. Hydrogen has to be packaged by compression or liquefaction, transported by surface vehicles or pipelines, stored and transferred to the end user. Whether generated by electrolysis or by reforming, and even if produced locally at filling stations, the gaseous or liquid hydrogen has to undergo these market processes before it can be used by the customer. In order to provide an idea of possible markets with special emphasis on the German energy sector, a technical systems analysis of possible hydrogen applications is performed for the stationary, mobile and portable sector. Furthermore, different 'business as usual' scenarios are analysed for Germany, Europe and the World concerning end energy use in different sectors. The very small assumed penetration of hydrogen in the analysed scenarios up to the year 2050 indicates that the hydrogen economy is a long-term option. With reference to the assumed supply paths and analysed application possibilities, hydrogen can be an option for clean energy use if hydrogen can be produced with carbon-reduced or -free primary energy carriers like renewable energy or biomass. However, the energetic use of hydrogen competes with the direct use of clean primary energy and/or with the use of electric energy based on renewable primary energy. As a substitution product for other secondary energy carriers hydrogen is therefore under pressure of costs and/or must have advantages in comparison to the use of

An energy self-sufficient public building using integrated renewable sources and hydrogen storage

International Nuclear Information System (INIS)

Marino, C.; Nucara, A.; Pietrafesa, M.; Pudano, A.

2013-01-01

The control of the use of fossil fuels, major cause of greenhouse gas emissions and climate changes, in present days represents one of Governments' main challenges; particularly, a significant energy consumption is observed in buildings and might be significantly reduced through sustainable design, increased energy efficiency and use of renewable sources. At the moment, the widespread use of renewable energy in buildings is limited by its intrinsic discontinuity: consequently integration of plants with energy storage systems could represent an efficient solution to the problem. Within this frame, hydrogen has shown to be particularly fit in order to be used as an energetic carrier. In this aim, in the paper an energetic, economic and environmental analysis of two different configurations of a self-sufficient system for energy production from renewable sources in buildings is presented. In particular, in the first configuration energy production is carried out by means of photovoltaic systems, whereas in the second one a combination of photovoltaic panels and wind generators is used. In both configurations, hydrogen is used as an energy carrier, in order to store energy, and fuel cells guarantee its energetic reconversion. The analysis carried out shows that, although dimensioned as a stand-alone configuration, the system can today be realized only taking advantage from the incentivizing fares applied to grid-connected systems, that are likely to be suspended in the next future. In such case, it represents an interesting investment, with capital returns in about 15 years. As concerns economic sustainability, in fact, the analysis shows that the cost of the energy unit stored in hydrogen volumes, due to the not very high efficiency of the process, presently results greater than that of directly used one. Moreover, also the starting fund of the system proves to be very high, showing an additional cost with respect to systems lacking of energy storage equal to about 50

Are renewable energy policies upsetting carbon dioxide emissions? The case of Latin America countries.

Science.gov (United States)

Fuinhas, José Alberto; Marques, António Cardoso; Koengkan, Matheus

2017-06-01

The impact of renewable energy policies in carbon dioxide emissions was analysed for a panel of ten Latin American countries, for the period from 1991 to 2012. Panel autoregressive distributed lag methodology was used to decompose the total effect of renewable energy policies on carbon dioxide emissions in its short- and long-run components. There is evidence for the presence of cross-sectional dependence, confirming that Latin American countries share spatial patterns. Heteroskedasticity, contemporaneous correlation, and first-order autocorrelation cross-sectional dependence are also present. To cope with these phenomena, the robust dynamic Driscoll-Kraay estimator, with fixed effects, was used. It was confirmed that the primary energy consumption per capita, in both the short- and long-run, contributes to an increase in carbon dioxide emissions, and also that renewable energy policies in the long-run, and renewable electricity generation per capita both in the short- and long-run, help to mitigate per capita carbon dioxide emissions.

Amorphous carbon enhancement of hydrogen penetration into UO2

International Nuclear Information System (INIS)

Zalkind, S.; Shamir, N.; Gouder, T.; Akhvlediani, R.; Hoffman, A.

2014-01-01

In a previous study, it was demonstrated that an amorphous carbon layer, deposited on a native oxide covered uranium surface, significantly enhances the interaction of hydrogen with the uranium metal. Fig. 1[2], demonstrates the preferential hydrogen attack (forming uranium hydride) on the carbon covered area of the naturally oxidized uranium metal

Carbide-Derived Carbons with Tunable Porosity Optimized for Hydrogen Storage

Energy Technology Data Exchange (ETDEWEB)

Fisher, John E.; Gogotsi, Yury; Yildirim, Taner

2010-01-07

On-board hydrogen storage is a key requirement for fuel cell-powered cars and trucks. Porous carbon-based materials can in principle adsorb more hydrogen per unit weight at room temperature than liquid hydrogen at -176 oC. Achieving this goal requires interconnected pores with very high internal surface area, and binding energies between hydrogen and carbon significantly enhanced relative to H2 on graphite. In this project a systematic study of carbide-derived carbons, a novel form of porous carbon, was carried out to discover a high-performance hydrogen sorption material to meet the goal. In the event we were unable to improve on the state of the art in terms of stored hydrogen per unit weight, having encountered the same fundamental limit of all porous carbons: the very weak interaction between H2 and the carbon surface. On the other hand we did discover several strategies to improve storage capacity on a volume basis, which should be applicable to other forms of porous carbon. Further discoveries with potentially broader impacts include • Proof that storage performance is not directly related to pore surface area, as had been previously claimed. Small pores (< 1.5 nm) are much more effective in storing hydrogen than larger ones, such that many materials with large total surface areas are sub-par performers. • Established that the distribution of pore sizes can be controlled during CDC synthesis, which opens the possibility of developing high performance materials within a common family while targeting widely disparate applications. Examples being actively pursued with other funding sources include methane storage, electrode materials for batteries and supercapacitors with record high specific capacitance, and perm-selective membranes which bind cytokines for control of infections and possibly hemodialysis filters.

Carbon hybridized halloysite nanotubes for high-performance hydrogen storage capacities

Science.gov (United States)

Jin, Jiao; Fu, Liangjie; Yang, Huaming; Ouyang, Jing

2015-01-01

Hybrid nanotubes of carbon and halloysite nanotubes (HNTs) with different carbon:HNTs ratio were hydrothermally synthesized from natural halloysite and sucrose. The samples display uniformly cylindrical hollow tubular structure with different morphologies. These hybrid nanotubes were concluded to be promising medium for physisorption-based hydrogen storage. The hydrogen adsorption capacity of pristine HNTs was 0.35% at 2.65 MPa and 298 K, while that of carbon coated HNTs with the pre-set carbon:HNTs ratio of 3:1 (3C-HNTs) was 0.48% under the same condition. This carbon coated method could offer a new pattern for increasing the hydrogen adsorption capacity. It was also possible to enhance the hydrogen adsorption capacity through the spillover mechanism by incorporating palladium (Pd) in the samples of HNTs (Pd-HNTs) and 3C-HNTs (Pd-3C-HNTs and 3C-Pd-HNTs are the samples with different location of Pd nanoparticles). The hydrogen adsorption capacity of the Pd-HNTs was 0.50% at 2.65 MPa and 298 K, while those of Pd-3C-HNTs and 3C-Pd-HNTs were 0.58% and 0.63%, respectively. In particular, for this spillover mechanism of Pd-carbon-HNTs ternary system, the bidirectional transmission of atomic and molecular hydrogen (3C-Pd-HNTs) was concluded to be more effective than the unidirectional transmission (Pd-3C-HNTs) in this work for the first time. PMID:26201827

Influence of activated carbon amended ASBR on anaerobic fermentative hydrogen production

DEFF Research Database (Denmark)

Xie, Li; Wang, Lei; Zhou, Qi

2013-01-01

The effect of activated carbon amended ASBR on fermentative bio-hydgrogen production from glucose was evaluated at hydraulic retention time (HRTs) ranging from 48 h to 12 h with initial pH of 6.0 at the system temperature of 60°C. Experimental results showed that the performance of activated carbon...... amended anazrobic seguencs batch reactor (ASBRs) was more stable than that of ASBRs without activated carbon addition regarding on hydrogen production and pH. Higher hydrogen yield(HY) and hydrogen producing rate(HPR) were observed in the activated carbon amended ASBRs, with 65%, 63%, 54%, 56% enhancement...... of hydrogen yield in smaller size activated carbon amended reactor under the tested HRT ranges, and the maximum HPR of (7.09±0.31)L·(L·d)-1 and HY of (1.42±0.03) mol·mol-1 was obtained at HRT of 12h. The major soluble products form hydrogen fermentation were n-butyric acid and acetic acid, accounting for 46...

Noncatalytic hydrogenation of decene-1 with hydrogen accumulated in a hybrid carbon nanostructure in nanosized membrane reactors

Science.gov (United States)

Soldatov, A. P.

2014-08-01

Studies on the creation of nanosized membrane reactors (NMRs) of a new generation with accumulated hydrogen and a regulated volume of reaction zone were continued at the next stage. Hydrogenation was performed in the pores of ceramic membranes with hydrogen preliminarily adsorbed in mono- and multilayered orientated carbon nanotubes with graphene walls (OCNTGs)—a new hybrid carbon nanostructure formed on the inner pore surface. Quantitative determination of hydrogen adsorption in OCNTGs was performed using TRUMEM ultrafiltration membranes with D av = 50 and 90 nm and showed that hydrogen adsorption was up to ˜1.5% of the mass of OCNTG. The instrumentation and procedure for noncatalytic hydrogenation of decene-1 at 250-350°C using hydrogen accumulated and stored in OCNTG were developed. The conversion of decene-1 into decane was ˜0.2-1.8% at hydrogenation temperatures of 250 and 350°C, respectively. The rate constants and activation energy of hydrogenation were determined. The latter was found to be 94.5 kJ/mol, which is much smaller than the values typical for noncatalytic hydrogenations and very close to the values characteristic for catalytic reactions. The quantitative distribution of the reacting compounds in each pore regarded as a nanosized membrane reactor was determined. The activity of hydrogen adsorbed in a 2D carbon nanostructure was evaluated. Possible mechanisms of noncatalytic hydrogenation were discussed.

Building sustainable energy systems: the role of nuclear-derived hydrogen

International Nuclear Information System (INIS)

Hans-Holger Rogner; Sanborn Scott, D.

2001-01-01

Global climate change is the most critical environmental threat of the 21. century. As evidenced in the preliminary draft of the Intergovernmental Panel on Climate Change (IPCC) new Third Assessment Report (TAR), the scientific support for this conclusion is both extensive and growing. In this paper we first review features of the 21. century energy system - how that system evolved and where it seems to be taking us, unless there are clear and aggressive multinational initiatives to mitigate and then reverse the contribution that today's energy system makes to the risks of global climate change. The paper then turns to the extensive deployment of the two non-carbon based energy currencies electricity and hydrogen, which we will call hydricity, that we believe are essential for future reductions in anthropogenic carbon dioxide (CO 2 ) emissions. Of these two, hydrogen will be the newcomer to energy systems. Popular thinking often identifies renewable as the category of energy sources that can provide electricity and hydrogen in sufficient quantities, although much of the public does not realize there will still be a need for a chemical currency to allow renewable to power the market where carbon is most difficult to mitigate, transportation. Renewable, however, while able to make important contributions to future energy supplies, cannot realistically provide the magnitude of energy that will be required. The paper outlines the quantitative limits to the overall renewable contribution and argues that the large-scale deployment of nuclear fission will be essential for meeting future energy needs while limiting greenhouse gas (GHG) emissions. (authors)

The Economic Potential of Nuclear-Renewable Hybrid Energy Systems Producing Hydrogen

Energy Technology Data Exchange (ETDEWEB)

Ruth, Mark [National Renewable Energy Lab. (NREL), Golden, CO (United States); Cutler, Dylan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Flores-Espino, Francisco [National Renewable Energy Lab. (NREL), Golden, CO (United States); Stark, Greg [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2017-04-01

This report is one in a series of reports that Idaho National Laboratory and the Joint Institute for Strategic Energy Analysis are publishing that address the technical and economic aspects of nuclear-renewable hybrid energy systems (N-R HESs). This report discusses an analysis of the economic potential of a tightly coupled N-R HES that produces electricity and hydrogen. Both low and high temperature electrolysis options are considered in the analysis. Low-temperature electrolysis requires only electricity to convert water to hydrogen. High temperature electrolysis requires less electricity because it uses both electricity and heat to provide the energy necessary to electrolyze water. The study finds that, to be profitable, the examined high-temperature electrosis and low-temperature electrosis N-R HES configurations that produce hydrogen require higher electricity prices, more electricity price volatility, higher natural gas prices, or higher capacity payments than the reference case values of these parameters considered in this analysis.

GAT 4 production and storage of hydrogen. Report July 2004

International Nuclear Information System (INIS)

2004-01-01

This paper concerns two aspects of the hydrogen: the production and the storage. For both parts the challenges and a state of the art are presented. It discusses also the hydrogen production by renewable energies, by solar energy, the hydrogen of hydrocarbons reforming purification, active phases development, thermal transfer simulation. Concerning the hydrogen storage the hydrogen adsorption by large surface solid, the storage by metallic hydrides, the alanates and light hydrides, the adsorption on carbon nano-tubes, the storage in nano-structures, the thermal and mechanical simulation of the hydrogen are presented. (A.L.B.)

Effect of high pressure hydrogen on the mechanical characteristics of single carbon fiber

Science.gov (United States)

Jeon, Sang Koo; Kwon, Oh Heon; Jang, Hoon-Sik; Ryu, Kwon Sang; Nahm, Seung Hoon

2018-02-01

In this study, carbon fiber was exposed to a pressure of 7 MPa for 24 h in high pressure chamber. The tensile test for carbon fiber was conducted to estimate the effect on the high pressure hydrogen in the atmosphere. To determine the tensile strength and Weibull modulus, approximately thirty carbon fiber samples were measured in all cases, and carbon fiber exposed to high pressure argon was evaluated to verify only the effect of hydrogen. Additionally, carbon fiber samples were annealed at 1950 °C for 1 h for a comparison with normal carbon fiber and then tested under identical conditions. The results showed that the tensile strength scatter of normal carbon fiber exposed to hydrogen was relatively wider and the Weibull modulus was decreased. Moreover, the tensile strength of the annealed carbon fiber exposed to hydrogen was increased, and these samples indicated a complex Weibull modulus because the hydrogen stored in the carbon fiber influenced the mechanical characteristic.

System and method for integration of renewable energy and fuel cell for the production of electricity and hydrogen

NARCIS (Netherlands)

Hemmes, K.

2007-01-01

The invention relates to a system and method for integrating renewable energy and a fuel cell for the production of electricity and hydrogen, wherein this comprises the use of renewable energy as fluctuating energy source for the production of electricity and also comprises the use of at least one

A biosensor for hydrogen peroxide detection based on electronic properties of carbon nanotubes

Science.gov (United States)

Majidi, Roya

2013-01-01

Density functional theory has been used to study the effect of hydrogen peroxide on the electronic properties of single walled carbon nanotubes. The metallic and semiconducting carbon nanotubes have been considered in the presence of different number of hydrogen peroxide. The results indicate that hydrogen peroxide has no significant effect on the metallic nanotube and these nanotubes remain to be metallic. In contrast, the electronic properties of the semiconducting nanotubes are so sensitive to hydrogen peroxide. The energy band gap of these nanotubes is decreased by increasing the number of hydrogen peroxide. The electronic sensivity of the carbon nanotubes to hydrogen peroxide opens new insights into developing biosensors based on the single walled carbon nanotubes.

Beneficial effect of carbon on hydrogen desorption kinetics from Mg–Ni–In alloy

International Nuclear Information System (INIS)

Cermak, J.; Kral, L.

2013-01-01

Highlights: ► Beneficial effect of graphitic carbon was observed. ► The effect is optimal up to c opt . ► Above c opt , phase decomposition occurs. ► Indium in studied Mg–Ni-based alloys prevents oxidation. - Abstract: In the present paper, hydrogen desorption kinetics from hydrided Mg–Ni–In–C alloys was investigated. A chemical composition that substantially accelerates hydrogen desorption was found. It was observed that carbon improves the hydrogen desorption kinetics significantly. Its beneficial effect was found to be optimum close to the carbon concentration of about c C ≅ 5 wt.%. With this composition, stored hydrogen can be desorbed readily at temperatures down to about 485 K, immediately after hydrogen charging. This can substantially shorten the hydrogen charging/discharging cycle of storage tanks using Mg–Ni-based alloys as hydrogen storage medium. For higher carbon concentrations, unwanted phases precipitated, likely resulting in deceleration of hydrogen desorption and lower hydrogen storage capacity.

Carbon dioxide hydrogenation to aromatic hydrocarbons by using an iron/iron oxide nanocatalyst

Directory of Open Access Journals (Sweden)

Hongwang Wang

2014-06-01

Full Text Available The quest for renewable and cleaner energy sources to meet the rapid population and economic growth is more urgent than ever before. Being the most abundant carbon source in the atmosphere of Earth, CO2 can be used as an inexpensive C1 building block in the synthesis of aromatic fuels for internal combustion engines. We designed a process capable of synthesizing benzene, toluene, xylenes and mesitylene from CO2 and H2 at modest temperatures (T = 380 to 540 °C employing Fe/Fe3O4 nanoparticles as catalyst. The synthesis of the catalyst and the mechanism of CO2-hydrogenation will be discussed, as well as further applications of Fe/Fe3O4 nanoparticles in catalysis.

Hydrogen Adsorption on Activated Carbon an Carbon Nanotubes Using Volumetric Differential Pressure Technique

International Nuclear Information System (INIS)

Sanip, S. M.; Saidin, M. A. R.; Aziz, M.; Ismail, A. F.

2010-01-01

A simple hydrogen adsorption measurement system utilizing the volumetric differential pressure technique has been designed, fabricated and calibrated. Hydrogen adsorption measurements have been carried out at temperatures 298 K and 77 K on activate carbon and carbon nanotubes with different surface areas. The adsorption data obtained will be helpful in understanding the adsorption property of the studied carbon materials using the fundamentals of adsorption theory. The principle of the system follows the Sievert-type method. The system measures a change in pressure between the reference cell, R1 and the sample cell S1, S2, S3 over a certain temperature range, R1, S1, S2, and S3 having known fixed volume. The sample temperatures will be monitored by thermocouple TC while the pressures in R1 an S1, S2, S3 will be measured using a digital pressure transducer. The maximum operating pressure of the pressure transducer is 20 bar and calibrated with an accuracy of ±0.01 bar. High purity hydrogen is being used in the system and the amount of samples for the study is between 1.0-2.0 grams. The system was calibrated using helium gas without any samples in S1, S2 an S3. This will provide a correction factor during the adsorption process providing an adsorption free reference point when using hydrogen gas resulting in a more accurate reading of the adsorption process by eliminating the errors caused by temperature expansion effects and other non-adsorption related phenomena. The ideal gas equation of state is applied to calculate the hydrogen adsorption capacity based on the differential pressure measurements. Activated carbon with a surface area of 644.87 m 2 /g showed a larger amount of adsorption as compared to multiwalled nanotubes (commercial) with a surface area of 119.68 m 2 /g. This study als indicated that there is a direct correlation between the amounts of hydrogen adsorbed an surface area of the carbon materials under the conditions studied and that the adsorption

Two different carbon-hydrogen complexes in silicon with closely spaced energy levels

Energy Technology Data Exchange (ETDEWEB)

Stübner, R., E-mail: ronald.stuebner@physik.tu-dresden.de, E-mail: kolkov@ifpan.edu.pl; Kolkovsky, Vl., E-mail: ronald.stuebner@physik.tu-dresden.de, E-mail: kolkov@ifpan.edu.pl; Weber, J. [Technische Universität Dresden, Institut für Angewandte Physik, 01062 Dresden (Germany)

2015-08-07

An acceptor and a single donor state of carbon-hydrogen defects (CH{sub A} and CH{sub B}) are observed by Laplace deep level transient spectroscopy at 90 K. CH{sub A} appears directly after hydrogenation by wet chemical etching or hydrogen plasma treatment, whereas CH{sub B} can be observed only after a successive annealing under reverse bias at about 320 K. The activation enthalpies of these states are 0.16 eV for CH{sub A} and 0.14 eV for CH{sub B}. Our results reconcile previous controversial experimental results. We attribute CH{sub A} to the configuration where substitutional carbon binds a hydrogen atom on a bond centered position between carbon and the neighboring silicon and CH{sub B} to another carbon-hydrogen defect.

Relative economic incentives for hydrogen from nuclear, renewable, and fossil energy sources

International Nuclear Information System (INIS)

Gorensek, Maximilian B.; Forsberg, Charles W.

2009-01-01

The specific hydrogen market determines the value of hydrogen from different sources. Each hydrogen production technology has its own distinct characteristics. For example, steam reforming of natural gas produces only hydrogen. In contrast, nuclear and solar hydrogen production facilities produce hydrogen together with oxygen as a by-product or co-product. For a user who needs both oxygen and hydrogen, the value of hydrogen from nuclear and solar plants is higher than that from a fossil plant because ''free'' oxygen is produced as a by-product. Six factors that impact the relative economics of fossil, nuclear, and solar hydrogen production to the customer are identified: oxygen by-product, avoidance of carbon dioxide emissions, hydrogen transport costs, storage costs, availability of low-cost heat, and institutional factors. These factors imply that different hydrogen production technologies will be competitive in different markets and that the first markets for nuclear and solar hydrogen will be those markets in which they have a unique competitive advantage. These secondary economic factors are described and quantified in terms of dollars per kilogram of hydrogen. (author)

The effect of atomic hydrogen adsorption on single-walled carbon nano tubes properties

International Nuclear Information System (INIS)

Jalili, S.; Majidi, R.

2007-01-01

We investigated the adsorption of hydrogen atoms on metallic single-walled carbon nano tubes using ab initio molecular dynamics method. It was found that the geometric structures and the electronic properties of hydrogenated SWNTs can be strongly changed by varying hydrogen coverage. The circular cross sections of the CNTs were changed with different hydrogen coverage. When hydrogen is chemisorbed on the surface of the carbon nano tube, the energy gap will be appeared. This is due to the degree of the Sp 3 hybridization, and the hydrogen coverage can control the band gap of the carbon nano tube

Evaluation tool for selection and optimisation of hydrogen demonstration projects. Application to a decentralized renewable hydrogen system

International Nuclear Information System (INIS)

Bracht, M.; De Groot, A.; Gregoire Padro, C.E.; Schucan, T.H.; Skolnik, E.

1998-06-01

As part of the International Energy Agency Hydrogen Implementing Agreement, an evaluation tool to assist in the design, operation and optimisation of hydrogen demonstration facilities is under development. Using commercially available flowsheet simulation software (ASPEN- Plus) as the integrating platform, this tool is designed to provide system developers with a comprehensive data base or library of component models and an integrating platform through which these models may be linked. By combining several energy system components a conceptual design of a integrated hydrogen energy system can be made. As a part of the tool and connected to the library are design guidelines which can help finding the optimal configuration in the design process. The component categories considered include: production, storage, transport, distribution and end use. Many component models have already been included in the initial test platform. The use of the tool will be illustrated by presenting the results of a specific sample system that has been designed and assessed with use of the tool. The system considered is a decentralized renewable hydrogen system in which the hydrogen is produced by biomass gasification or pyrolysis, the produced hydrogen is transported through a pipeline or with a tank truck. The storage options that are considered are liquid hydrogen and compressed gas. The hydrogen is dispensed through a refueling station. Several options for integration are conceivable; i.e. storage of the hydrogen can take place centrally or district heat of a gasification unit can be used to generate electricity for liquefaction, etc. With use of the tool several configurations with different components and various integration options have been examined. Both the results of the modeling effort and an assessment of the evaluation tool will be presented. 5 refs

Microwave interaction with nonuniform hydrogen gas in carbon nanotubes

International Nuclear Information System (INIS)

Babaei, S.; Babaei, Sh.

2009-01-01

In this paper we study the reflection, absorption, and transmission of microwave from nonuniform hydrogen gas in carbon nanotubes, grown by iron-catalyzed high-pressure carbon monoxide disproportionate (HiPco) process. A discussion on the effect of various hydrogen gas parameters on the reflected power, absorbed power, and transmitted power is presented. The nonuniform hydrogen gas slab is modeled by a series of subslabs. The overall number density profile across the whole slab follows a parabolic function. The total reflected, absorbed, and transmitted powers are then deduced and their functional dependence on the number density, collision frequency, and angle of propagation is studied

Carbon dioxide management by chemical conversion to methanol: HYDROGENATION and BI-REFORMING

International Nuclear Information System (INIS)

Wiesberg, Igor L.; Medeiros, José Luiz de; Alves, Rita M.B.; Coutinho, Paulo L.A.; Araújo, Ofélia Q.F.

2016-01-01

Highlights: • Evaluation of carbon dioxide conversion to methanol by two chemical routes. • HYDROGENATION: conversion via catalytic hydrogenation at high pressure. • BI-REFORMING: conversion via syngas from bi-reforming of natural gas. • HYDROGENATION is viable for hydrogen price inferior to 1000 US$/t. • BI-REFORMING is unable to avoid emissions; viable only if gas price is very low. - Abstract: Chemical conversion of carbon dioxide to methanol has the potential to address two relevant sustainability issues: economically feasible replacement of fossil raw materials and avoidance of greenhouse gas emissions. However, chemical stability of carbon dioxide is a challenging impediment to conversion requiring severe reaction conditions at the expense of increased energy input, therefore adding capital, operation and environmental costs, which could result in partial or total override of its potential sustainability as feedstock to the chemical and energy industries. This work investigates two innovative chemical destinations of carbon dioxide to methanol, namely a direct conversion through carbon dioxide hydrogenation (HYDROGENATION), and an indirect via carbon dioxide conversion to syngas through bi-reforming (BI-REFORMING). Process simulation is used to obtain mass and energy balances needed to support assessment of economic and environmental performance. A business scenario is considered where an industrial source of nearly pure carbon dioxide exists and an investment decision for utilization of carbon dioxide is faced. Due to uncertainties in prices of the raw materials, hydrogen (HYDROGENATION) and natural gas (BI-REFORMING), the decision procedure includes the definition of price thresholds to reach profitability. Sensitivity analyses are performed varying costs with greater uncertainty, i.e., carbon dioxide and methanol, and recalculating maximum allowable prices of raw materials. The analyses show that in a Brazilian scenario, BI-REFORMING is unlikely

Clean energy and the hydrogen economy.

Science.gov (United States)

Brandon, N P; Kurban, Z

2017-07-28

In recent years, new-found interest in the hydrogen economy from both industry and academia has helped to shed light on its potential. Hydrogen can enable an energy revolution by providing much needed flexibility in renewable energy systems. As a clean energy carrier, hydrogen offers a range of benefits for simultaneously decarbonizing the transport, residential, commercial and industrial sectors. Hydrogen is shown here to have synergies with other low-carbon alternatives, and can enable a more cost-effective transition to de-carbonized and cleaner energy systems. This paper presents the opportunities for the use of hydrogen in key sectors of the economy and identifies the benefits and challenges within the hydrogen supply chain for power-to-gas, power-to-power and gas-to-gas supply pathways. While industry players have already started the market introduction of hydrogen fuel cell systems, including fuel cell electric vehicles and micro-combined heat and power devices, the use of hydrogen at grid scale requires the challenges of clean hydrogen production, bulk storage and distribution to be resolved. Ultimately, greater government support, in partnership with industry and academia, is still needed to realize hydrogen's potential across all economic sectors.This article is part of the themed issue 'The challenges of hydrogen and metals'. © 2017 The Author(s).

Paramagnetic defects in hydrogenated amorphous carbon powders

International Nuclear Information System (INIS)

Keeble, D J; Robb, K M; Smith, G M; Mkami, H El; Rodil, S E; Robertson, J

2003-01-01

Hydrogenated amorphous carbon materials typically contain high concentrations of paramagnetic defects, the density of which can be quantified by electron paramagnetic resonance (EPR). In this work EPR measurements near 9.5, 94, and 189 GHz have been performed on polymeric and diamond-like hydrogenated amorphous carbon (a-C:H) powder samples. A similar single resonance line was observed at all frequencies for the two forms of a-C:H studied. No contributions to the spectrum from centres with resolved anisotropic g-values as reported earlier were detected. An increase in linewidth with microwave frequency was observed. Possible contributions to this frequency dependence are discussed

Theoretical analysis of hydrogen spillover mechanism on carbon nanotubes

Directory of Open Access Journals (Sweden)

Rosalba eJuarez Mosqueda

2015-02-01

Full Text Available The spillover mechanism of molecular hydrogen on carbon nanotubes in the presence of catalytically active platinum clusters was critically and systematically investigated by using density-functional theory. Our simulation model includes a Pt4 cluster for the catalyst nanoparticle and curved and planar circumcoronene for two exemplary single-walled carbon nanotubes (CNT, the (10,10 CNT and one of large diameter, respectively. Our results show that the H2 molecule dissociates spontaneously on the Pt4 cluster. However, the dissociated H atoms have to overcome a barrier of more than 2 eV to migrate from the catalyst to the CNT, even if the Pt4 cluster is at full saturation with six adsorbed and dissociated hydrogen molecules. Previous investigations have shown that the mobility of hydrogen atoms on the CNT surface is hindered by a barrier. We find that instead the Pt4 catalyst may move along the outer surface of the CNT with activation energy of only 0.16 eV, and that this effect offers the possibility of full hydrogenation of the CNT. Thus, although we have not found a low-energy pathway to spillover onto the CNT, we suggest, based on our calculations and calculated data reported in the literature, that in the hydrogen-spillover process the observed saturation of the CNT at hydrogen background pressure occurs through mobile Pt nanoclusters, which move on the substrate more easily than the substrate-chemisorbed hydrogens, and deposit or reattach hydrogens in the process. Initial hydrogenation of the carbon substrate, however, is thermodynamically unfavoured, suggesting that defects should play a significant role.

Hydrogen-enriched natural gas; Bridge to an ultra low carbon world

Energy Technology Data Exchange (ETDEWEB)

Samuel, Joshua; Oliver, Mike

2010-09-15

Natural gas is recognized as an important part of the solution to climate change, as it has the smallest carbon footprint among fossil fuels and can be used with high efficiency. This alone is not enough. Supplementing natural gas with hydrogen creating hydrogen-enriched natural gas (HENG), where the hydrogen comes from a low- or zero-carbon energy source. HENG, the subject of this paper, can leverage existing natural gas infrastructure to reduce CO2 and NOx, improve the efficiency of end-use equipment, and lower the overall carbon intensity of energy consumption.

From water to water, hydrogen as a renewable energy vector for the future

International Nuclear Information System (INIS)

Gillet, A.C.

2000-01-01

The most important property of hydrogen is that it is the cleanest fuel. Its combustion produces only water and a small amount of NO x . No acid rain, no greenhouse effect, no ozone layer depletion, no particulates aerosols. It seems then ideally suited for the conversion to renewable energy. Hydrogen has now established it self as a clean choice for an environmentally compatible energy system. It can provide a sustainable future for building, industrial and transport sectors of human activities. On average, it has about 20-30% higher combustion efficiency than fossil fuels and can produce electricity directly in fuel cells. In combination with solar PV- and hydro-electrolysis, it is compatible with land area requirements on a worldwide basis. If fossil fuels combustion environmental damage is taken into account, the hydrogen energy system is already cost effective. The question is thus no longer , but, and soon, will hydrogen energy become a practical solution to sustainable energy development. (Author)

Hydrogen adsorption in the series of carbon nanostructures: Graphenes-graphene nanotubes-nanocrystallites

Science.gov (United States)

Soldatov, A. P.; Kirichenko, A. N.; Tat'yanin, E. V.

2016-07-01

A comparative analysis of hydrogen absorption capability is performed for the first time for three types of carbon nanostructures: graphenes, oriented carbon nanotubes with graphene walls (OCNTGs), and pyrocarbon nanocrystallites (PCNs) synthesized in the pores of TRUMEM ultrafiltration membranes with mean diameters ( D m) of 50 and 90 nm, using methane as the pyrolized gas. The morphology of the carbon nanostructures is studied by means of powder X-ray diffraction, X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and transmission electron microscopy (TEM). Hydrogen adsorption is investigated via thermogravimetric analysis (TGA) in combination with mass-spectrometry. It is shown that only OCNTGs can adsorb and store hydrogen, the desorption of which under atmospheric pressure occurs at a temperature of around 175°C. Hydrogen adsorption by OCNTGs is quantitatively determined and found to be about 1.5% of their mass. Applying certain assumptions, the relationship between the mass of carbon required for the formation of single-wall OCNTGs in membrane pores and the surface area of pores is established. Numerical factor Ψ = m dep/ m calc, where m dep is the actual mass of carbon deposited upon the formation of OCNTGs and mcalc is the calculated mass of carbon necessary for the formation of OCNTGs is introduced. It is found that the dependence of specific hydrogen adsorption on the magnitude of the factor has a maximum at Ψ = 1.2, and OCNTGs can adsorb and store hydrogen in the interval 0.4 to 0.6 hydrogen adsorption and its relationship to the structure of carbon nanoformations are examined.

Potential of hydrogen from oil palm biomass as a source of renewable energy worldwide

International Nuclear Information System (INIS)

Kelly-Yong, Tau Len; Lee, Keat Teong; Mohamed, Abdul Rahman; Bhatia, Subhash

2007-01-01

Various catastrophes related to extreme weather events such as floods, hurricanes, droughts and heat waves occurring on the Earth in the recent times are definitely a clear warning sign from nature questioning our ability to protect the environment and ultimately the Earth itself. Progressive release of greenhouse gases (GHG) such as CO 2 and CH 4 from development of various energy-intensive industries has ultimately caused human civilization to pay its debt. Realizing the urgency of reducing emissions and yet simultaneously catering to needs of industries, researches and scientists conclude that renewable energy is the perfect candidate to fulfill both parties requirement. Renewable energy provides an effective option for the provision of energy services from the technical point of view. In this context, biomass appears as one important renewable source of energy. Biomass has been a major source of energy in the world until before industrialization when fossil fuels become dominant and researches have proven from time to time its viability for large-scale production. Although there has been some successful industrial-scale production of renewable energy from biomass, generally this industry still faces a lot of challenges including the availability of economically viable technology, sophisticated and sustainable natural resources management, and proper market strategies under competitive energy markets. Amidst these challenges, the development and implementation of suitable policies by the local policy-makers is still the single and most important factor that can determine a successful utilization of renewable energy in a particular country. Ultimately, the race to the end line must begin with the proof of biomass ability to sustain in a long run as a sustainable and reliable source of renewable energy. Thus, the aim of this paper is to present the potential availability of oil palm biomass that can be converted to hydrogen (leading candidate positioned as the

Hydrogen storage by carbon materials synthesized from oil seeds and fibrous plant materials

Energy Technology Data Exchange (ETDEWEB)

Sharon, Maheshwar; Bhardwaj, Sunil; Jaybhaye, Sandesh [Nanotechnology Research Center, Birla College, Kalyan 421304 (India); Soga, T.; Afre, Rakesh [Graduate School of Engineering, Nagoya Institute of Technology, Nagoya (Japan); Sathiyamoorthy, D.; Dasgupta, K. [Powder Metallurgy Division, BARC, Trombay 400 085 (India); Sharon, Madhuri [Monad Nanotech Pvt. Ltd., A702 Bhawani Tower, Powai, Mumbai 400 076 (India)

2007-12-15

Carbon materials of various morphologies have been synthesized by pyrolysis of various oil-seeds and plant's fibrous materials. These materials are characterized by SEM and Raman. Surface areas of these materials are determined by methylene blue method. These carbon porous materials are used for hydrogen storage. Carbon fibers with channel type structure are obtained from baggas and coconut fibers. It is reported that amongst the different plant based precursors studied, carbon from soyabean (1.09 wt%) and baggas (2.05 wt%) gave the better capacity to store hydrogen at 11kg/m{sup 2} pressure of hydrogen at room temperature. Efforts are made to correlate the hydrogen adsorption capacity with intensities and peak positions of G- and D-band obtained with carbon materials synthesized from plant based precursors. It is suggested that carbon materials whose G-band is around 1575cm{sup -1} and the intensity of D-band is less compared to G-band, may be useful material for hydrogen adsorption study. (author)

Carbon nanotube materials for hydrogen storage

Energy Technology Data Exchange (ETDEWEB)

Dillon, A.C.; Parilla, P.A.; Jones, K.M.; Riker, G.; Heben, M.J. [National Renewable Energy Lab., Golden, CO (United States)

1998-08-01

Carbon single-wall nanotubes (SWNTs) are essentially elongated pores of molecular dimensions and are capable of adsorbing hydrogen at relatively high temperatures and low pressures. This behavior is unique to these materials and indicates that SWNTs are the ideal building block for constructing safe, efficient, and high energy density adsorbents for hydrogen storage applications. In past work the authors developed methods for preparing and opening SWNTs, discovered the unique adsorption properties of these new materials, confirmed that hydrogen is stabilized by physical rather than chemical interactions, measured the strength of interaction to be {approximately} 5 times higher than for adsorption on planar graphite, and performed infrared absorption spectroscopy to determine the chemical nature of the surface terminations before, during, and after oxidation. This year the authors have made significant advances in synthesis and characterization of SWNT materials so that they can now prepare gram quantities of high-purity SWNT samples and measure and control the diameter distribution of the tubes by varying key parameters during synthesis. They have also developed methods which purify nanotubes and cut nanotubes into shorter segments. These capabilities provide a means for opening the tubes which were unreactive to the oxidation methods that successfully opened tubes, and offer a path towards organizing nanotube segments to enable high volumetric hydrogen storage densities. They also performed temperature programmed desorption spectroscopy on high purity carbon nanotube material obtained from collaborator Prof. Patrick Bernier and finished construction of a high precision Seivert`s apparatus which will allow the hydrogen pressure-temperature-composition phase diagrams to be evaluated for SWNT materials.

Thermal stability of hydrogenated small-diameter carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

Podlivaev, A. I., E-mail: AIPodlivayev@mephi.ru; Openov, L. A. [National Research Nuclear University “MEPhI” (Russian Federation)

2017-02-15

The initial stage of hydrogen desorption from fully hydrogenated carbon nanotubes (3.0) and (2.2) is numerically studied by the molecular dynamics method. The temperature dependence of the desorption rate is directly determined at T = 1800–2500 K. The characteristic desorption times are determined at temperatures outside this range by extrapolation. It is shown that hydrogen desorption leads to the appearance of electronic states in the band gap.

A study on hydrogen storage through adsorption in nano-structured carbons

International Nuclear Information System (INIS)

Langohr, D.

2004-10-01

The aim of this work is to build and calibrate an experimental set-up for the testing of the materials, to produce some carbon materials in large amounts and characterise them, and finally, to test these materials in their ability to store hydrogen. This will help in establishing a link between the hydrogen storage capacities of the carbons and their nano-structure. The script is divided into four chapters. The first chapter will deal with the literature review on the thematic of hydrogen storage through adsorption in the carbon materials, while the second chapter will present the experimental set-up elaborated in the laboratory. The third chapter explains the processes used to produce the two families of carbon materials and finally, the last chapter presents the structural characterisation of the samples as well as the experimental results of hydrogen storage on the materials elaborated. (author)

Fuel and Chemicals from Renewable Alcohols

DEFF Research Database (Denmark)

Hansen, Jeppe Rass

2008-01-01

The present work entitled Fuel and Chemicals from Renewable Alcohols covers the idea of developing routes for producing sustainable fuel and chemicals from biomass resources. Some renewable alcohols are already readily available from biomass in significant amounts and thus the potential...... for these renewable alcohols, together with other primary renewable building blocks, has been highlighted in the introductory chapter. While the first chapter covers the general potential of a renewable chemical industry, the other chapters deal with particular possibilities. It is shown how ethanol and glycerol can...... be converted into hydrogen by steam reforming over nickel or ruthenium based catalysts. This process could be important in a future hydrogen society, where hydrogen can be utilized in high efficiency fuel cells. Hydrogen produced from biofeedstocks can also be used directly in the chemical industry, where...

An examination of isolated, stationary, hydrogen power systems supplied by renewables: component and system issues and criteria necessary for successful worldwide deployment

Energy Technology Data Exchange (ETDEWEB)

Rambach, G. D. [Energy and Environmental Engineering Center, Desert Research Institute, Reno, NV (United States)

1999-12-01

The premise of this paper is that remote, stationary power systems, based on indigenous renewable energy sources, are an ideal market entry opportunity for hydrogen, but that the deployment of isolated power systems relying on hydrogen as the energy storage medium requires complex and comprehensive planning and design considerations to provide for successful market entry strategies and appropriate systems engineering. Accordingly, this paper sets out to discuss the criteria and the framework necessary to determine how to successfully deploy any specific system or to plan a global marketing strategy. Details of the indigenous intermittent energy sources (wind turbines, solar photovoltaic, micro-hydroelectric, etc), primary power-to-hydrogen conversion systems, hydrogen storage methods, and hydrogen-to-electricity conversion systems (hydrogen-internal combustion engine generator set, hydrogen fuel cells) are described, along with the criteria for technically and commercially successful deployment of any renewable utility power system that employs energy storage.2 refs., 4 figs.

Performance of CVD and CVR coated carbon-carbon in high temperature hydrogen

Science.gov (United States)

Adams, J. W.; Barletta, R. E.; Svandrlik, J.; Vanier, P. E.

As a part of the component development process for the particle bed reactor (PBR), it is necessary to develop coatings which will be time and temperature stable at extremely high temperatures in flowing hydrogen. These coatings must protect the underlying carbon structure from attack by the hydrogen coolant. Degradation which causes small changes in the reactor component, e.g. hole diameter in the hot frit, can have a profound effect on operation. The ability of a component to withstand repeated temperature cycles is also a coating development issue. Coatings which crack or spall under these conditions would be unacceptable. While refractory carbides appear to be the coating material of choice for carbon substrates being used in PBR components, the method of applying these coatings can have a large effect on their performance. Two deposition processes for these refractory carbides, chemical vapor deposition (CVD) and chemical vapor reaction (CVR), have been evaluated. Screening tests for these coatings consisted of testing of coated 2-D and 3-D weave carbon-carbon in flowing hot hydrogen at one atmosphere. Carbon loss from these samples was measured as a function of time. Exposure temperatures up to 3,000 K were used, and samples were exposed in a cyclical fashion cooling to room temperature between exposures. The results of these measurements are presented along with an evaluation of the relative merits of CVR and CVD coatings for this application.

Mechanism of obtaining carbon monoxide and hydrogen during brown coal radiolysis. [Gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Rustamov, V R; Kurbanov, M A; Dzantiev, B T; Kerimov, V K; Musaeva, P F

1982-05-01

This article analyzes effects of gamma radiation on the yield of products of coal gasification: hydrogen and carbon monoxide. Samples of brown coal from the Kansk-Achins basin were treated by gamma radiation with cobalt 60 radiation source. Analyses show that accumulation of hydrogen and carbon monoxide in brown coal under influence of gamma radiation is characterized by a constant rate. Yields of carbon monoxide and hydrogen amount to 0.16 molecule/100 electro volt and 0.21 molecule/electro volt respectively. Reducing radiation dose from 2.5 to 0.7 millirad/h reduces yields of hydrogen and carbon monoxide. Increasing temperature of vacuum brown coal pyrolysis from 200 to 600 C causes decrease of hydrogen yield. Hydrogen yield decrease during temperature increase is caused by a high content of aromatic nuclei in the samples used in the radiolysis. (5 refs.)

Interactions between California's Low Carbon Fuel Standard and the National Renewable Fuel Standard

International Nuclear Information System (INIS)

Whistance, Jarrett; Thompson, Wyatt; Meyer, Seth

2017-01-01

This study investigates the economic interactions between a national renewable fuel policy, namely the Renewable Fuel Standard (RFS) in the United States, and a sub-national renewable fuel policy, the Low Carbon Fuel Standard (LCFS) in California. The two policies have a similar objective of reducing greenhouse gas emissions, but the policies differ in the manner in which those objectives are met. The RFS imposes a hierarchical mandate of renewable fuel use for each year whereas the LCFS imposes a specific annual carbon-intensity reduction with less of a fuel specific mandate. We model the interactions using a partial-equilibrium structural model of agricultural and energy markets in the US and Rest-of-World regions. Our results suggest the policies are mutually reinforcing in that the compliance costs of meeting one of the requirements is lower in the presence of the other policy. In addition, the two policies combine to create a spatial shift in renewable fuel use toward California even though overall renewable fuel use remains relatively unchanged. - Highlights: • Results suggest the RFS and LCFS are mutually reinforcing. • Overall level of renewable fuel use is similar across scenarios. • Renewable fuel use shifts toward California in the presence of the LCFS. • Higher ethanol blend (e.g. E85) use also shifts toward California.

Hydrogen storage capacity of lithium-doped KOH activated carbons

International Nuclear Information System (INIS)

Minoda, Ai; Oshima, Shinji; Iki, Hideshi; Akiba, Etsuo

2014-01-01

Highlights: • The hydrogen adsorption of lithium-doped KOH activated carbons has been studied. • Lithium doping improves their hydrogen adsorption affinity. • Lithium doping is more effective for materials with micropores of 0.8 nm or smaller. • Lithium reagent can alter the pore structure, depending on the raw material. • Optimizing the pore size and functional group is needed for better hydrogen uptake. - Abstract: The authors have studied the hydrogen adsorption performance of several types of lithium-doped KOH activated carbons. In the case of activated cokes, lithium doping improves their hydrogen adsorption affinity from 5.02 kg/m 3 to 5.86 kg/m 3 at 303 K. Hydrogen adsorption density increases by around 17% after lithium doping, likely due to the fact that lithium doping is more effective for materials with micropores of 0.8 nm or smaller. The effects of lithium on hydrogen storage capacity vary depending on the raw material, because the lithium reagent can react with the material and alter the pore structure, indicating that lithium doping has the effect of plugging or filling the micropores and changing the structures of functional groups, resulting in the formation of mesopores. Despite an observed decrease in hydrogen uptake, lithium doping was found to improve hydrogen adsorption affinity. Lithium doping increases hydrogen uptake by optimizing the pore size and functional group composition

Investigate of analysis for hydrogen contents in carbon films

International Nuclear Information System (INIS)

Yasui, Haruyuki; Hirose, Yukio; Sasaki, Toshihiko; Awazu, Kaoru; Naramoto, Hiroshi

2001-01-01

Hydrogen is a very common contaminant in carbon films. It can strongly influences on mechanical, physical and chemical properties of the films. The analysis of hydrogen is therefore a crucial problem to prepare the films with the reproducible property. We were measured two kinds of methods. Ion beam techniques using nuclear reactions are established methods for the quantitative determination of hydrogen concentration. A spectrometer has been constructed for the determination of hydrogen concentrations by detecting 4.43 MeV γ-rays from the resonant nuclear reactions 1 H( 15 N, α γ) 12 C at the 6.385 MeV. And the other measurement of hydrogen is GDOES (Glow Discharge Optical Emission Spectroscopy), with its high sputtering rates, had been used previously for depth profiling analysis of thin films. The depth profiling analysis was carried out at an argon atmosphere by applying an RF of 13.56 MHz. The sampling time interval was 0.1 sec. The detailed hydrogen analysis was made on BCN (Boron Carbonitride) and DLC (Diamond-like Carbon) thin films. The BCN films were prepared by ion beam assisted deposition, in which boron and carbon were deposited by electron beam heating of B 4 C solid and nitrogen was supplied by implantation simultaneously. The DLC films were prepared by HPPC (Hybrid-pulse plasma coating) system. It was a new coating system that we developed which consists fundamentally of plasma CVD (chemical vapor deposition) and ion-mixing. In this paper, we reported the comparison of analysis for hydrogen contents between RNRA and GDOES. (author)

Investigate of analysis for hydrogen contents in carbon films

Energy Technology Data Exchange (ETDEWEB)

Yasui, Haruyuki; Hirose, Yukio; Sasaki, Toshihiko [Kanazawa Univ., Kanazawa, Ishikawa (Japan); Awazu, Kaoru [Industrial Research Institute of Ishikawa, Kanazawa, Ishikawa (Japan); Naramoto, Hiroshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

2001-07-01

Hydrogen is a very common contaminant in carbon films. It can strongly influences on mechanical, physical and chemical properties of the films. The analysis of hydrogen is therefore a crucial problem to prepare the films with the reproducible property. We were measured two kinds of methods. Ion beam techniques using nuclear reactions are established methods for the quantitative determination of hydrogen concentration. A spectrometer has been constructed for the determination of hydrogen concentrations by detecting 4.43 MeV {gamma}-rays from the resonant nuclear reactions {sup 1}H({sup 15}N, {alpha} {gamma}){sup 12}C at the 6.385 MeV. And the other measurement of hydrogen is GDOES (Glow Discharge Optical Emission Spectroscopy), with its high sputtering rates, had been used previously for depth profiling analysis of thin films. The depth profiling analysis was carried out at an argon atmosphere by applying an RF of 13.56 MHz. The sampling time interval was 0.1 sec. The detailed hydrogen analysis was made on BCN (Boron Carbonitride) and DLC (Diamond-like Carbon) thin films. The BCN films were prepared by ion beam assisted deposition, in which boron and carbon were deposited by electron beam heating of B{sub 4}C solid and nitrogen was supplied by implantation simultaneously. The DLC films were prepared by HPPC (Hybrid-pulse plasma coating) system. It was a new coating system that we developed which consists fundamentally of plasma CVD (chemical vapor deposition) and ion-mixing. In this paper, we reported the comparison of analysis for hydrogen contents between RNRA and GDOES. (author)

Monte-Carlo Simulation of Hydrogen Adsorption in Single-Wall Carbon Nano-Cones

Directory of Open Access Journals (Sweden)

Zohreh Ahadi

2011-01-01

Full Text Available The properties of hydrogen adsorption in single-walled carbon nano-cones are investigated in detail by Monte Carlo simulations. A great deal of our computational results show that the hydrogen storage capacity in single-walled carbon nano-cones is slightly smaller than the capacity of single-walled carbon nanotubes at any time at the same conditions. This indicates that the hydrogen storage capacity of single-walled carbon nano-cones is related to angles of carbon nano-cones. It seems that these type of nanotubes could not exceed the 2010 goal of 6 wt%, which is presented by the U.S. Department of Energy. In addition, these results are discussed in theory.

Hydrogen as a renewable and sustainable solution in reducing global fossil fuel consumption

International Nuclear Information System (INIS)

Midilli, Adnan; Dincer, Ibrahim

2008-01-01

In this paper, hydrogen is considered as a renewable and sustainable solution for reducing global fossil fuel consumption and combating global warming and studied exergetically through a parametric performance analysis. The environmental impact results are then compared with the ones obtained for fossil fuels. In this regard, some exergetic expressions are derived depending primarily upon the exergetic utilization ratios of fossil fuels and hydrogen: the fossil fuel based global waste exergy factor, hydrogen based global exergetic efficiency, fossil fuel based global irreversibility coefficient and hydrogen based global exergetic indicator. These relations incorporate predicted exergetic utilization ratios for hydrogen energy from non-fossil fuel resources such as water, etc., and are used to investigate whether or not exergetic utilization of hydrogen can significantly reduce the fossil fuel based global irreversibility coefficient (ranging from 1 to +∞) indicating the fossil fuel consumption and contribute to increase the hydrogen based global exergetic indicator (ranging from 0 to 1) indicating the hydrogen utilization at a certain ratio of fossil fuel utilization. In order to verify all these exergetic expressions, the actual fossil fuel consumption and production data are taken from the literature. Due to the unavailability of appropriate hydrogen data for analysis, it is assumed that the utilization ratios of hydrogen are ranged between 0 and 1. For the verification of these parameters, the variations of fossil fuel based global irreversibility coefficient and hydrogen based global exergetic indicator as the functions of fossil fuel based global waste exergy factor, hydrogen based global exergetic efficiency and exergetic utilization of hydrogen from non-fossil fuels are analyzed and discussed in detail. Consequently, if exergetic utilization ratio of hydrogen from non-fossil fuel sources at a certain exergetic utilization ratio of fossil fuels increases

Hydrogen storage in porous carbons: modelling and performance improvements

International Nuclear Information System (INIS)

Pellenq, R.J.M.; Maresca, O.; Marinelli, F.; Duclaux, L.; Azais, P.; Conard, J.

2006-01-01

In this work, we aim at exploring using ab initio calculations, the various ways allowing for an efficient hydrogen docking in carbon porous materials. Firstly, the influence of surface curvature on the chemisorption of atomic hydrogen is considered. Then it is shown that electro-donor elements such as lithium or potassium used as dopant of the carbon substrate induce a strong physi-sorption for H 2 , allowing its storage at ambient temperature under moderate pressure. (authors)

Energy–exergy and economic analyses of a hybrid solar–hydrogen renewable energy system in Ankara, Turkey

International Nuclear Information System (INIS)

Ozden, Ender; Tari, Ilker

2016-01-01

Highlights: • Uninterrupted energy in an emergency blackout situation. • System modeling of a solar–hydrogen based hybrid renewable energy system. • A comprehensive thermodynamical analysis. • Levelized cost of electricity analysis for a project lifetime of 25 years. - Abstract: A hybrid (Solar–Hydrogen) stand-alone renewable energy system that consists of photovoltaic panels (PV), Proton Exchange Membrane (PEM) fuel cells, PEM based electrolyzers and hydrogen storage is investigated by developing a complete model of the system using TRNSYS. The PV panels are mounted on a tiltable platform to improve the performance of the system by monthly adjustments of the tilt angle. The total area of the PV panels is 300 m 2 , the PEM fuel cell capacity is 5 kW, and the hydrogen storage is at 55 bars pressure and with 45 m 3 capacity. The main goal of this study is to verify that the system meets the electrical power demand of the emergency room without experiencing a shortage for a complete year in an emergency blackout situation. For this purpose, after modeling the system, energy and exergy analyses for the hydrogen cycle of the system for a complete year are performed, and the energy and exergy efficiencies are found as 4.06% and 4.25%, respectively. Furthermore, an economic analysis is performed for a project lifetime of 25 years based on Levelized Cost of Electricity (LCE), and the LCE is calculated as 0.626 $/kWh.

Physisorption of molecular hydrogen on carbon nanotube with vacant defects

Energy Technology Data Exchange (ETDEWEB)

Sun, Gang; Shen, Huaze; Wang, Enge; Xu, Limei, E-mail: limei.xu@pku.edu.cn [International Center for Quantum Materials and School of Physics, Peking University, Beijing 100871 (China); Collaborative Innovation Center of Quantum Matter, Beijing (China); Tangpanitanon, Jirawat [University of Cambridge, Cambridge, Cambridgeshire CB2 1TP (United Kingdom); Wen, Bo [International Center for Quantum Materials and School of Physics, Peking University, Beijing 100871 (China); Beijing Computational Science Research Center, Heqing Street, Haidian District, Beijing 100084 (China); Xue, Jianming [State Key Laboratory of Nuclear Physics and Technology, School of Physics, Peking University, Beijing 100871 (China); Center for Applied Physics and Technology, Peking University, Beijing 100871 (China)

2014-05-28

Physisorption of molecular hydrogen on single-walled carbon nanotubes (SWCNTs) is important for its engineering applications and hydrogen energy storage. Using molecular dynamics simulation, we study the physisorption of molecular hydrogen on a SWCNT with a vacant defect, focusing on the effect of the vacant defect size and external parameters such as temperature and pressure. We find that hydrogen can be physisorbed inside a SWCNT through a vacant defect when the defect size is above a threshold. By controlling the size of the defects, we are able to extract hydrogen molecules from a gas mixture and store them inside the SWCNT. We also find that external parameters, such as low temperature and high pressure, enhance the physisorption of hydrogen molecules inside the SWCNT. In addition, the storage efficiency can be improved by introducing more defects, i.e., reducing the number of carbon atoms on the SWCNT.

Physisorption of molecular hydrogen on carbon nanotube with vacant defects

Science.gov (United States)

Sun, Gang; Tangpanitanon, Jirawat; Shen, Huaze; Wen, Bo; Xue, Jianming; Wang, Enge; Xu, Limei

2014-05-01

Physisorption of molecular hydrogen on single-walled carbon nanotubes (SWCNTs) is important for its engineering applications and hydrogen energy storage. Using molecular dynamics simulation, we study the physisorption of molecular hydrogen on a SWCNT with a vacant defect, focusing on the effect of the vacant defect size and external parameters such as temperature and pressure. We find that hydrogen can be physisorbed inside a SWCNT through a vacant defect when the defect size is above a threshold. By controlling the size of the defects, we are able to extract hydrogen molecules from a gas mixture and store them inside the SWCNT. We also find that external parameters, such as low temperature and high pressure, enhance the physisorption of hydrogen molecules inside the SWCNT. In addition, the storage efficiency can be improved by introducing more defects, i.e., reducing the number of carbon atoms on the SWCNT.

Physisorption of molecular hydrogen on carbon nanotube with vacant defects

International Nuclear Information System (INIS)

Sun, Gang; Shen, Huaze; Wang, Enge; Xu, Limei; Tangpanitanon, Jirawat; Wen, Bo; Xue, Jianming

2014-01-01

Physisorption of molecular hydrogen on single-walled carbon nanotubes (SWCNTs) is important for its engineering applications and hydrogen energy storage. Using molecular dynamics simulation, we study the physisorption of molecular hydrogen on a SWCNT with a vacant defect, focusing on the effect of the vacant defect size and external parameters such as temperature and pressure. We find that hydrogen can be physisorbed inside a SWCNT through a vacant defect when the defect size is above a threshold. By controlling the size of the defects, we are able to extract hydrogen molecules from a gas mixture and store them inside the SWCNT. We also find that external parameters, such as low temperature and high pressure, enhance the physisorption of hydrogen molecules inside the SWCNT. In addition, the storage efficiency can be improved by introducing more defects, i.e., reducing the number of carbon atoms on the SWCNT

Alternatives to electricity for transmission and annual-scale firming - Storage for diverse, stranded, renewable energy resources: hydrogen and ammonia

Energy Technology Data Exchange (ETDEWEB)

Leighty, William

2010-09-15

The world's richest renewable energy resources 'of large geographic extent and high intensity' are stranded: far from end-users with inadequate or nonexistent gathering and transmission systems to deliver energy. Output of most renewables varies greatly, at time scales of seconds-seasons: energy capture assets operate at low capacity factor; energy delivery is not 'firm'. New electric transmission systems, or fractions thereof, dedicated to renewables, suffer the same low CF: substantial stranded capital assets, increasing the cost of delivered renewable-source energy. Electricity storage cannot affordably firm large renewables at annual scale. Gaseous hydrogen and anhydrous ammonia fuels can: attractive alternatives.

An examination of the criteria necessary for successful worldwide deployment of isolated, renewable hydrogen stationary power systems

International Nuclear Information System (INIS)

Rambach, G. D.; Snyder, J. D.

1998-01-01

This paper examines the top-down rationale and methods for using hydrogen as an energy carrier in isolated, stationary power systems. Such an examination can be useful because it provides a framework for detailed research on subsystems and helps clarify why, when and where large-scale hydrogen use would be beneficial. It also helps define the pathway for an evolving hydrogen stationary power market worldwide. Remote, stationary power systems are an ideal market entry opportunity for hydrogen. For example, if it is sufficiently difficult for conventional fuels to reach a community, and indigenous renewable sources are present, then on-site clean energy production becomes economically competitive. Relying heavily on intermittent sources of energy requires an energy carrier system that is efficient over long periods of time. In addition, the energy carrier must not defeat the reasons for initially switching to the clean sources of energy, and must be economically feasible. Hydrogen is an elegant solution to all of these needs. Choices exist for the methods of producing hydrogen, storing and transporting it, and converting it back to useful energy. There is considerable debate about how best to increase the use of renewable hydrogen because it is not yet economically competitive with conventional energy carriers in most applications. The deployment of isolated power systems relying on hydrogen as the energy storage medium requires complex and comprehensive planning and design considerations to provide successful market entry strategies as well as appropriate system engineering. This paper will discuss the criteria and framework necessary to determine how to successfully deploy any specific system or to plan a global marketing strategy. (author)

The Investments in Renewable Energy Sources: Do Low Carbon Economies Better Invest in Green Technologies?

Directory of Open Access Journals (Sweden)

Antonio Angelo Romano

2011-01-01

Full Text Available The aim of this study is to analyse the driving of investment in renewable energy sources in low carbon and high carbon economies. To address these issues, a dynamic panel analysis of the renewable investment in a sample of 29 countries was proposed. Results demonstrate that the dynamic of investments in renewable sources is similar in the two panels, and depends by nuclear power generation, GDP and technological efficiency. Results show that countries try to reduce their environmental footprint, decreasing the CO2 intensity. Based on the estimation results, we think that energy sustainability passes through the use of renewable resources that can complement the nuclear technology on condition that both exceed their limits.

Collision cascades enhanced hydrogen redistribution in cobalt implanted hydrogenated diamond-like carbon films

International Nuclear Information System (INIS)

Gupta, P.; Becker, H.-W.; Williams, G.V.M.; Hübner, R.; Heinig, K.-H.; Markwitz, A.

2017-01-01

Highlights: • This paper reports for the first time redistribution of hydrogen atoms in diamond like carbon thin films during ion implantation of low energy magnetic ions. • The results point towards new routes of controlling the composition and distribution of elements at the nanoscale within a base matrix without using any heat treatment methods. • Exploring these opportunities can lead to a new horizon of materials and device engineering needed for enabling advanced technologies and applications. - Abstract: Hydrogenated diamond-like carbon films produced by C_3H_6 deposition at 5 kV and implanted at room temperature with 30 keV Co atoms to 12 at.% show not only a bimodal distribution of Co atoms but also a massive redistribution of hydrogen in the films. Resonant nuclear reaction analysis was used to measure the hydrogen depth profiles (15N-method). Depletion of hydrogen near the surface was measured to be as low as 7 at.% followed by hydrogen accumulation from 27 to 35 at.%. A model is proposed considering the thermal energy deposited by collision cascade for thermal insulators. In this model, sufficient energy is provided for dissociated hydrogen to diffuse out of the sample from the surface and diffuse into the sample towards the interface which is however limited by the range of the incoming Co ions. At a hydrogen concentration of ∼35 at.%, the concentration gradient of the mobile unbounded hydrogen atoms is neutralised effectively stopping diffusion towards the interface. The results point towards new routes of controlling the composition and distribution of elements at the nanoscale within a base matrix without using any heat treatment methods. Exploring these opportunities can lead to a new horizon of materials and device engineering needed for enabling advanced technologies and applications.

Collision cascades enhanced hydrogen redistribution in cobalt implanted hydrogenated diamond-like carbon films

Energy Technology Data Exchange (ETDEWEB)

Gupta, P. [National Isotope Centre, GNS Science, Lower Hutt (New Zealand); The MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington (New Zealand); Becker, H.-W. [RUBION, Ruhr-University Bochum (Germany); Williams, G.V.M. [The MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington (New Zealand); Hübner, R.; Heinig, K.-H. [Institute of Ion Beam Physics and Materials Research, Helmholtz-Zentrum Dresden-Rossendorf (Germany); Markwitz, A., E-mail: a.markwitz@gns.cri.nz [National Isotope Centre, GNS Science, Lower Hutt (New Zealand); The MacDiarmid Institute for Advanced Materials and Nanotechnology, School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington (New Zealand)

2017-03-01

Highlights: • This paper reports for the first time redistribution of hydrogen atoms in diamond like carbon thin films during ion implantation of low energy magnetic ions. • The results point towards new routes of controlling the composition and distribution of elements at the nanoscale within a base matrix without using any heat treatment methods. • Exploring these opportunities can lead to a new horizon of materials and device engineering needed for enabling advanced technologies and applications. - Abstract: Hydrogenated diamond-like carbon films produced by C{sub 3}H{sub 6} deposition at 5 kV and implanted at room temperature with 30 keV Co atoms to 12 at.% show not only a bimodal distribution of Co atoms but also a massive redistribution of hydrogen in the films. Resonant nuclear reaction analysis was used to measure the hydrogen depth profiles (15N-method). Depletion of hydrogen near the surface was measured to be as low as 7 at.% followed by hydrogen accumulation from 27 to 35 at.%. A model is proposed considering the thermal energy deposited by collision cascade for thermal insulators. In this model, sufficient energy is provided for dissociated hydrogen to diffuse out of the sample from the surface and diffuse into the sample towards the interface which is however limited by the range of the incoming Co ions. At a hydrogen concentration of ∼35 at.%, the concentration gradient of the mobile unbounded hydrogen atoms is neutralised effectively stopping diffusion towards the interface. The results point towards new routes of controlling the composition and distribution of elements at the nanoscale within a base matrix without using any heat treatment methods. Exploring these opportunities can lead to a new horizon of materials and device engineering needed for enabling advanced technologies and applications.

Hydrogenation of carbon to methane in reduced sponge iron, chromium, and ferrochromium

Energy Technology Data Exchange (ETDEWEB)

Qayyum, M A; Reeve, D A

1976-01-01

Hydrogenation of excess carbon to methane in reduced sponge iron, chromium and ferrochromium under isothermal and temperature-programmed conditions indicates that it is possible to control the residual carbon content of the metallized products which may be an advantage if further processing of the products is contemplated. Hydrogenation starts above 800/sup 0/C and a shrinking-core kinetic model fits the experimental data. The mean apparent activation energy for the hydrogenation of residual carbon to methane in sponge iron, chromium and ferrochromium is 21 kcal/mole.

Development of Affordable, Low-Carbon Hydrogen Supplies at an Industrial Scale

Science.gov (United States)

Roddy, Dermot J.

2008-01-01

An existing industrial hydrogen generation and distribution infrastructure is described, and a number of large-scale investment projects are outlined. All of these projects have the potential to generate significant volumes of low-cost, low-carbon hydrogen. The technologies concerned range from gasification of coal with carbon capture and storage…

Carbon Reduction Measures-Based LCA of Prefabricated Temporary Housing with Renewable Energy Systems

Directory of Open Access Journals (Sweden)

Ling Dong

2018-03-01

Full Text Available Temporary housing plays an important role in providing secure, hygienic, private, and comfortable shelter in the aftermath of disaster (such as flood, fire, earthquake, etc.. Additionally, temporary housing can also be used as a sustainable form of on-site residences for construction workers. While most of the building components used in temporary housing can be manufactured in a plant, prefabrication technology improves the production efficiency of temporary housing; furthermore, integrated renewable energy systems, for example, solar photovoltaic (PV system, offer benefits for temporary housing operations. In order to assess the environmental impacts of prefabricated temporary housing equipped with renewable energy systems, this study first divides the life cycle of temporary housing into six stages, and then establishes a life cycle assessment (LCA model for each stage. Furthermore, with the aim of reducing the environmental impacts, life cycle carbon reduction measures are proposed for each stage of temporary housing. The proposed methodology is demonstrated using a case study in China. Based on the proposed carbon reduction measures, the LCA of a prefabricated temporary housing case study building equipped with renewable energy systems indicates a carbon emissions intensity of 35.7 kg/m2·per year, as well as a reduction in material embodied emissions of 18%, assembly emissions of 17.5%, and operational emissions of 91.5%. This research proposes a carbon reduction-driven LCA of temporary housing and contributes to promoting sustainable development of prefabricated temporary housing equipped with renewable energy systems.

Sintering uranium oxide in the reaction product of hydrogen-carbon dioxide mixtures

International Nuclear Information System (INIS)

De Hollander, W.R.; Nivas, Y.

1975-01-01

Compacted pellets of uranium oxide alone or containing one or more additives such as plutonium dioxide, gadolinium oxide, titanium dioxide, silica, and alumina are heated to 900 to 1599 0 C in the presence of a mixture of hydrogen and carbon dioxide, either alone or with an inert carrier gas and held at the desired temperature in this atmosphere to sinter the pellets. The sintered pellets are then cooled in an atmosphere having an oxygen partial pressure of 10 -4 to 10 -18 atm of oxygen such as dry hydrogen, wet hydrogen, dry carbon monoxide, wet carbon monoxide, inert gases such as nitrogen, argon, helium, and neon and mixtures of ayny of the foregoing including a mixture of hydrogen and carbon dioxide. The ratio of hydrogen to carbon dioxide in the gas mixture fed to the furnace is controlled to give a ratio of oxygen to uranium atoms in the sintered particles within the range of 1.98:1 to about 2.10:1. The water vapor present in the reaction products in the furnace atmosphere acts as a hydrolysis agent to aid removal of fluoride should such impurity be present in the uranium oxide. (U.S.)

Extraction of Carbon Dioxide and Hydrogen from Seawater and Hydrocarbon Production Therefrom

Science.gov (United States)

2016-04-05

acidification of seawater by subjecting the seawater to an ion exchange reaction to exchange H.sup. ions for Na.sup. ions. Carbon dioxide may be...extracted from the acidified seawater. Optionally, the ion exchange reaction can be conducted under conditions which produce hydrogen as well as carbon dioxide . The carbon dioxide and hydrogen may be used to produce hydrocarbons.

Annex 15 of the IEA Hydrogen Implementing Agreement : Photobiological hydrogen production

Energy Technology Data Exchange (ETDEWEB)

Lindblad, P. [Uppsala Univ., Uppsala (Sweden)]|[International Energy Agency, Paris (France)

2004-07-01

Task 15 of the Hydrogen Implementation Agreement of the International Energy Agency is to advance the science of biophotosynthesis of hydrogen, which is the biological production of hydrogen from water and sunlight using microalgal photosynthesis. A practical process for biophotolysis would result in an innovative biological source of sustainable and environmentally benign renewable energy source. Japan, Norway, Sweden and the United States initially committed to the project. Since then Canada, the Netherlands and the United Kingdom have joined. The current task is to produce hydrogen from both green algae and cyanobacteria with focus on early-stage applied research on biophotolysis processes with intermediate carbon dioxide fixation. Significant advances have also occurred in the scientific field of cyanobacterial biohydrogen. Cyanobacteria has enzymes that metabolise hydrogen. Photosynthetic cyanobacteria have simple nutritional requirements and can grow in air, water, or mineral salts with light as the only source of energy. This research will help provide the advances needed to achieve practical efficiencies and cost objectives of biological hydrogen production. tabs., figs.

Substitutability of Electricity and Renewable Materials for Fossil Fuels in a Post-Carbon Economy

Directory of Open Access Journals (Sweden)

Antonio García-Olivares

2015-11-01

Full Text Available A feasible way to avoid the risk of energy decline and combat climate change is to build a 100% renewable global energy mix. However, a globally electrified economy cannot grow much above 12 electric terawatts without putting pressure on the limits of finite mineral reserves. Here we analyze whether 12 TW of electricity and 1 TW of biomass (final power will be able to fuel a future post-carbon economy that can provide similar services to those of a contemporary economy. Contrarily to some pessimistic expectations, this analysis shows that the principle economic processes can be replaced with sustainable alternatives based on electricity, charcoal, biogas and hydrogen. Furthermore, those services that cannot be replaced are not as crucial so as to cause a return to a pre-industrial society. Even so, land transport and aviation are at the limit of what is sustainable, outdoor work should be reorganized, metal primary production should be based on hydrogen reduction when possible, mineral production should be increasingly based on recycling, the petrochemical industry should shrink to a size of 40%–43% of the 2012 petrochemical sector, i.e., a size similar to that the sector had in 1985–1986, and agriculture may require organic farming methods to be sustainable.

Characteristics of Biochar Obtained by Hydrothermal Carbonization of Cellulose for Renewable Energy

OpenAIRE

Daegi Kim; Kunio Yoshikawa; Ki Young Park

2015-01-01

The effect of hydrothermal carbonization on the properties of cellulose present in lignocellulosic biomass was investigated for converting it into a renewable energy resource with high energy recovery efficiency. The biochar obtained from cellulose subjected to hydrothermal carbonization showed a significant increase in its carbon content and a calorific value. 13C NMR spectroscopy showed that when raw cellulose was subjected to hydrothermal carbonization above 220 °C, the resulting biochar h...

California-Specific Power-to-Hydrogen and Power-to-Gas Business Case Evaluation

Energy Technology Data Exchange (ETDEWEB)

Eichman, Joshua D. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Flores-Espino, Francisco [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2018-02-12

Flexible operation of electrolysis systems represents an opportunity to reduce the cost of hydrogen for a variety of end-uses while also supporting grid operations and thereby enabling greater renewable penetration. California is an ideal location to realize that value on account of growing renewable capacity and markets for hydrogen as a fuel cell electric vehicle (FCEV) fuel, refineries, and other end-uses. Shifting the production of hydrogen to avoid high cost electricity and participation in utility and system operator markets along with installing renewable generation to avoid utility charges and increase revenue from the Low Carbon Fuel Standard (LCFS) program can result in around $2.5/kg (21%) reduction in the production and delivery cost of hydrogen from electrolysis. This reduction can be achieved without impacting the consumers of hydrogen. Additionally, future strategies for reducing hydrogen cost were explored and include lower cost of capital, participation in the Renewable Fuel Standard program, capital cost reduction, and increased LCFS value. Each must be achieved independently and could each contribute to further reductions. Using the assumptions in this study found a 29% reduction in cost if all future strategies are realized. Flexible hydrogen production can simultaneously improve the performance and decarbonize multiple energy sectors. The lessons learned from this study should be used to understand near-term cost drivers and to support longer-term research activities to further improve cost effectiveness of grid integrated electrolysis systems.

Combined heat and power (cogeneration) plant based on renewable energy sources and electrochemical hydrogen systems

Science.gov (United States)

Grigor'ev, S. A.; Grigor'ev, A. S.; Kuleshov, N. V.; Fateev, V. N.; Kuleshov, V. N.

2015-02-01

The layout of a combined heat and power (cogeneration) plant based on renewable energy sources (RESs) and hydrogen electrochemical systems for the accumulation of energy via the direct and inverse conversion of the electrical energy from RESs into the chemical energy of hydrogen with the storage of the latter is described. Some efficient technical solutions on the use of electrochemical hydrogen systems in power engineering for the storage of energy with a cyclic energy conversion efficiency of more than 40% are proposed. It is shown that the storage of energy in the form of hydrogen is environmentally safe and considerably surpasses traditional accumulator batteries by its capacitance characteristics, being especially topical in the prolonged absence of energy supply from RESs, e.g., under the conditions of polar night and breathless weather. To provide the required heat consumption of an object during the peak period, it is proposed to burn some hydrogen in a boiler house.

Hydrogen production using thermocatalytic decomposition of methane on Ni30/activated carbon and Ni30/carbon black.

Science.gov (United States)

Srilatha, K; Viditha, V; Srinivasulu, D; Ramakrishna, S U B; Himabindu, V

2016-05-01

Hydrogen is an energy carrier of the future need. It could be produced from different sources and used for power generation or as a transport fuel which mainly in association with fuel cells. The primary challenge for hydrogen production is reducing the cost of production technologies to make the resulting hydrogen cost competitive with conventional fuels. Thermocatalytic decomposition (TCD) of methane is one of the most advantageous processes, which will meet the future demand, hence an attractive route for COx free environment. The present study deals with the production of hydrogen with 30 wt% of Ni impregnated in commercially available activated carbon and carbon black catalysts (samples coded as Ni30/AC and Ni30/CB, respectively). These combined catalysts were not attempted by previous studies. Pure form of hydrogen is produced at 850 °C and volume hourly space velocity (VHSV) of 1.62 L/h g on the activity of both the catalysts. The analysis (X-ray diffraction (XRD)) of the catalysts reveals moderately crystalline peaks of Ni, which might be responsible for the increase in catalytic life along with formation of carbon fibers. The activity of carbon black is sustainable for a longer time compared to that of activated carbon which has been confirmed by life time studies (850 °C and 54 sccm of methane).

Vision for a low-impact renewable energy future for Canada

International Nuclear Information System (INIS)

2003-11-01

The Clean Air Renewable Energy Coalition promotes the development of the renewable energy industry in Canada. The Coalition's vision for low-impact renewable energy focuses on green forms of electricity to provide not only light, heat and power, but to produce hydrogen fuel that could be used in fuel cell technologies. Low-impact renewable energy is a non-depleting resource with minimal environmental impacts. It includes wind energy, hydro energy, geothermal energy, biomass, tidal energy, and solar energy. The Coalition's goal is to have low-impact renewable energy account for at least 7 per cent of Canada's electricity production by 2010, and 15 per cent by 2020. It is currently at 1 per cent. This goal can be achieved by: defining a comprehensive renewable energy vision for Canada; setting long term targets for renewable energy in Canada; committing to a package of long term incentives; developing partnerships between all levels of government to increase financial investments in renewable energy projects; and, recognizing the potential for renewable energy in a carbon-constrained economy. refs., tabs

Photobiological hydrogen production and carbon dioxide sequestration

Science.gov (United States)

Berberoglu, Halil

Photobiological hydrogen production is an alternative to thermochemical and electrolytic technologies with the advantage of carbon dioxide sequestration. However, it suffers from low solar to hydrogen energy conversion efficiency due to limited light transfer, mass transfer, and nutrient medium composition. The present study aims at addressing these limitations and can be divided in three parts: (1) experimental measurements of the radiation characteristics of hydrogen producing and carbon dioxide consuming microorganisms, (2) solar radiation transfer modeling and simulation in photobioreactors, and (3) parametric experiments of photobiological hydrogen production and carbon dioxide sequestration. First, solar radiation transfer in photobioreactors containing microorganisms and bubbles was modeled using the radiative transport equation (RTE) and solved using the modified method of characteristics. The study concluded that Beer-Lambert's law gives inaccurate results and anisotropic scattering must be accounted for to predict the local irradiance inside a photobioreactor. The need for accurate measurement of the complete set of radiation characteristics of microorganisms was established. Then, experimental setup and analysis methods for measuring the complete set of radiation characteristics of microorganisms have been developed and successfully validated experimentally. A database of the radiation characteristics of representative microorganisms have been created including the cyanobacteria Anabaena variabilis, the purple non-sulfur bacteria Rhodobacter sphaeroides and the green algae Chlamydomonas reinhardtii along with its three genetically engineered strains. This enabled, for the first time, quantitative assessment of the effect of genetic engineering on the radiation characteristics of microorganisms. In addition, a parametric experimental study has been performed to model the growth, CO2 consumption, and H 2 production of Anabaena variabilis as functions of

Hydrogen evolution from water using solid carbon and light energy

Energy Technology Data Exchange (ETDEWEB)

Kawai, T; Sakata, T

1979-11-15

Hydrogen is produced from water vapour and solid carbon when mixed powders of TiO2, RuO2 and active carbon exposed to water vapor at room temperature, or up to 80 C, are illuminated. At 80 C, the rate of CO and COat2 formation increased. Therefore solar energy would be useful here as a combination of light energy and heat energy. Oxygen produced on the surface of the photocatalyst has a strong oxidising effect on the carbon. It is suggested that this process could be used for coal gasification and hydrogen production from water, accompanied by storage of solar energy.

Electrochemical Hydrogen Storage in Facile Synthesized Co@N-Doped Carbon Nanoparticle Composites.

Science.gov (United States)

Zhou, Lina; Qu, Xiaosheng; Zheng, Dong; Tang, Haolin; Liu, Dan; Qu, Deyang; Xie, ZhiZhong; Li, Junsheng; Qu, Deyu

2017-11-29

A Co@nitrogen-doped carbon nanoparticle composite was synthesized via a facile molecular self-assembling procedure. The material was used as the host for the electrochemical storage of hydrogen. The hydrogen storage capacity of the material was over 300 mAh g -1 at a rate of 100 mAg -1 . It also exhibited superior stability for storage of hydrogen, high rate capability, and good cyclic life. Hybridizing metallic cobalt nanoparticle with nitrogen-doped mesoporous carbon is found to be a good approach for the electrochemical storage of hydrogen.

Co-axial heterostructures integrating palladium/titanium dioxide with carbon nanotubes for efficient electrocatalytic hydrogen evolution

Science.gov (United States)

Valenti, Giovanni; Boni, Alessandro; Melchionna, Michele; Cargnello, Matteo; Nasi, Lucia; Bertoni, Giovanni; Gorte, Raymond J.; Marcaccio, Massimo; Rapino, Stefania; Bonchio, Marcella; Fornasiero, Paolo; Prato, Maurizio; Paolucci, Francesco

2016-12-01

Considering the depletion of fossil-fuel reserves and their negative environmental impact, new energy schemes must point towards alternative ecological processes. Efficient hydrogen evolution from water is one promising route towards a renewable energy economy and sustainable development. Here we show a tridimensional electrocatalytic interface, featuring a hierarchical, co-axial arrangement of a palladium/titanium dioxide layer on functionalized multi-walled carbon nanotubes. The resulting morphology leads to a merging of the conductive nanocarbon core with the active inorganic phase. A mechanistic synergy is envisioned by a cascade of catalytic events promoting water dissociation, hydride formation and hydrogen evolution. The nanohybrid exhibits a performance exceeding that of state-of-the-art electrocatalysts (turnover frequency of 15000 H2 per hour at 50 mV overpotential). The Tafel slope of ~130 mV per decade points to a rate-determining step comprised of water dissociation and formation of hydride. Comparative activities of the isolated components or their physical mixtures demonstrate that the good performance evolves from the synergistic hierarchical structure.

Palladium on Nitrogen-Doped Mesoporous Carbon: A Bifunctional Catalyst for Formate-Based, Carbon-Neutral Hydrogen Storage.

Science.gov (United States)

Wang, Fanan; Xu, Jinming; Shao, Xianzhao; Su, Xiong; Huang, Yanqiang; Zhang, Tao

2016-02-08

The lack of safe, efficient, and economical hydrogen storage technologies is a hindrance to the realization of the hydrogen economy. Reported herein is a reversible formate-based carbon-neutral hydrogen storage system that is established over a novel catalyst comprising palladium nanoparticles supported on nitrogen-doped mesoporous carbon. The support was fabricated by a hard template method and nitridated under a flow of ammonia. Detailed analyses demonstrate that this bicarbonate/formate redox equilibrium is promoted by the cooperative role of the doped nitrogen functionalities and the well-dispersed, electron-enriched palladium nanoparticles. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hydrogen storage in carbon nano-materials. Elaboration, characterization and properties

International Nuclear Information System (INIS)

Luxembourg, D.

2004-10-01

This work deals with hydrogen storage for supplying fuel cells. Hydrogen storage by adsorption in carbon nano-tubes and nano-fibers is a very controversial issue because experimental results are very dispersed and adsorption mechanisms are not yet elucidated. Physi-sorption cannot explain in fact all the experimental results. All the potential adsorption sites, physical and chemical, are discussed as detailed as possible in a state of the art. Experimental works includes the steps of elaboration, characterization, and measurements of the hydrogen storage properties. Nano-fibers are grown using a CVD approach. Single wall carbon nano-tubes (SWNT) synthesis is based on the vaporization/condensation of a carbon/catalysts mixture in a reactor using a fraction of the available concentrated solar energy at the focus of the 1000 kW solar facility of IMP-CNRS at Odeillo. Several samples are produced using different synthesis catalysts (Ni, Co, Y, Ce). SWNT samples are purified using oxidative and acid treatments. Hydrogen storage properties of these materials are carefully investigated using a volumetric technique. The applied pressure is up to 6 MPa and the temperature is 253 K. Hydrogen uptake of the investigated materials are less than 1 % wt. at 253 K and 6 MPa. (author)

California Power-to-Gas and Power-to-Hydrogen Near-Term Business Case Evaluation

Energy Technology Data Exchange (ETDEWEB)

Eichman, Josh [National Renewable Energy Lab. (NREL), Golden, CO (United States); Flores-Espino, Francisco [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2016-12-01

Flexible operation of electrolysis systems represents an opportunity to reduce the cost of hydrogen for a variety of end-uses while also supporting grid operations and thereby enabling greater renewable penetration. California is an ideal location to realize that value on account of growing renewable capacity and markets for hydrogen as a fuel cell electric vehicle (FCEV) fuel, refineries, and other end-uses. Shifting the production of hydrogen to avoid high cost electricity and participation in utility and system operator markets along with installing renewable generation to avoid utility charges and increase revenue from the Low Carbon Fuel Standard (LCFS) program can result in around $2.5/kg (21%) reduction in the production and delivery cost of hydrogen from electrolysis. This reduction can be achieved without impacting the consumers of hydrogen. Additionally, future strategies for reducing hydrogen cost were explored and include lower cost of capital, participation in the Renewable Fuel Standard program, capital cost reduction, and increased LCFS value. Each must be achieved independently and could each contribute to further reductions. Using the assumptions in this study found a 29% reduction in cost if all future strategies are realized. Flexible hydrogen production can simultaneously improve the performance and decarbonize multiple energy sectors. The lessons learned from this study should be used to understand near-term cost drivers and to support longer-term research activities to further improve cost effectiveness of grid integrated electrolysis systems.

Optimization of Nano-Carbon Materials for Hydrogen Sorption

Energy Technology Data Exchange (ETDEWEB)

Yakobson, Boris I [Rice University

2013-08-02

Research undertaken has added to the understanding of several critical areas, by providing both negative answers (and therefore eliminating expensive further studies of unfeasible paths) and positive feasible options for storage. Theoretical evaluation of the early hypothesis of storage on pure carbon single wall nanotubes (SWNT) has been scrutinized with the use of comprehensive computational methods (and experimental tests by the Center partners), and demonstrated that the fundamentally weak binding energy of hydrogen is not sufficiently enhanced by the SWNT curvature or even defects, which renders carbon nanotubes not practical media. More promising direction taken was towards 3-dimensional architectures of high porosity where concurrent attraction of H2 molecule to surrounding walls of nano-scale cavities can double or even triple the binding energy and therefore make hydrogen storage feasible even at ambient or somewhat lower temperatures. An efficient computational tool has been developed for the rapid capacity assessment combining (i) carbon-foam structure generation, (ii) accurate empirical force fields, with quantum corrections for the lightweight H2, and (iii) grand canonical Monte Carlo simulation. This made it possible to suggest optimal designs for carbon nanofoams, obtainable via welding techniques from SWNT or by growth on template-zeolites. As a precursor for 3D-foams, we have investigated experimentally the synthesis of VANTA (Vertically Aligned NanoTube Arrays). This can be used for producing nano-foams. On the other hand, fluorination of VANTA did not show promising increase of hydrogen sorption in several tests and may require further investigation and improvements. Another significant result of this project was in developing a fundamental understanding of the elements of hydrogen spillover mechanisms. The benefit of developed models is the ability to foresee possible directions for further improvement of the spillover mechanism.

Hydrogen Adsorption on Activated Carbon an Carbon Nanotubes Using Volumetric Differential Pressure Technique

Science.gov (United States)

Sanip, S. M.; Saidin, M. A. R.; Aziz, M.; Ismail, A. F.

2010-03-01

A simple hydrogen adsorption measurement system utilizing the volumetri differential pressure technique has been designed, fabricated and calibrated. Hydroge adsorption measurements have been carried out at temperatures 298 K and 77 K on activate carbon and carbon nanotubes with different surface areas. The adsorption data obtained will b helpful in understanding the adsorption property of the studied carbon materials using th fundamentals of adsorption theory. The principle of the system follows the Sievert-type metho The system measures a change in pressure between the reference cell, R1 and the sample cell S1, S2, S3 over a certain temperature range. R1, S1, S2, and S3 having known fixed volume The sample temperatures will be monitored by thermocouple TC while the pressures in R1 an S1, S2, S3 will be measured using a digital pressure transducer. The maximum operatin pressure of the pressure transducer is 20 bar and calibrated with an accuracy of ±0.01 bar. Hig purity hydrogen is being used in the system and the amount of samples for the study is betwee 1.0-2.0 grams. The system was calibrated using helium gas without any samples in S1, S2 an S3. This will provide a correction factor during the adsorption process providing an adsorption free reference point when using hydrogen gas resulting in a more accurate reading of th adsorption process by eliminating the errors caused by temperature expansion effects and oth non-adsorption related phenomena. The ideal gas equation of state is applied to calculate th hydrogen adsorption capacity based on the differential pressure measurements. Activated carbo with a surface area of 644.87 m2/g showed a larger amount of adsorption as compared to multiwalled nanotubes (commercial) with a surface area of 119.68 m2/g. This study als indicated that there is a direct correlation between the amounts of hydrogen adsorbed an surface area of the carbon materials under the conditions studied and that the adsorption significant at 77

Improving hydrogen storage in Ni-doped carbon nanospheres

Energy Technology Data Exchange (ETDEWEB)

Zubizarreta, L.; Menendez, J.A.; Pis, J.J.; Arenillas, A. [Instituto Nacional del Carbon, CSIC, Apartado 73, 33080 Oviedo (Spain)

2009-04-15

The effect of nickel distribution and content in Ni-doped carbon nanospheres on hydrogen storage capacity under conditions of moderate temperature and pressure was studied. It was found that the nickel distribution, obtained by using different doping techniques and conditions, has a noticeable influence on hydrogen storage capacity. The samples with the most homogeneous nickel distribution, obtained by pre-oxidising the carbon nanospheres, displayed the highest storage capacity. In addition, storage capacity is influenced by the amount of nickel. It was found a higher storage capacity in samples containing 5 wt.% of Ni. This is due to the greater interactions between the nickel and the support that produce a higher activation of the solid through a spillover effect. (author)

Release of hydrogen isotopes from carbon based fusion reactor materials

International Nuclear Information System (INIS)

Vainonen-Ahlgren, E.

2000-01-01

The purpose of this study is to understand the annealing behavior of hydrogen isotopes in carbon based materials. Also, the density of the material and structural changes after thermal treatment and ion irradiation are examined. The study of hydrogen diffusion in diamondlike carbon films revealed an activation energy of 2.0 eV, while the deuterium diffusion, due to better measuring sensitivity, is found to be concentration dependent with the effective diffusion coefficient becoming smaller with decreasing deuterium concentration. To explain the experimentally observed profiles, a model according to which atomic deuterium diffuses and deuterium in clusters is immobile is developed. The concentration of immobile D was assumed to be an analytical function of the total D concentration. To describe the annealing behavior of D incorporated in diamondlike carbon films during the deposition process, a model taking into account diffusion of free D and thermal detrapping and trapping of D was developed. The difference in the analysis explains the disagreement of activation energy (1.5 ± 0.2 eV) with the value of 2,9± 0.1 eV obtained for D implanted samples earlier. The same model was applied to describe the experimental profiles in Si doped diamondlike carbon films. Si affects the retention of D in diamondlike carbon films. The amount of D depends on Si content in the co-deposited but not implanted samples. Besides, Si incorporation into carbon coating decreases to some extent the graphitization of the films and leads to formation of a structure which is stable under thermal treatment and ion irradiation. Hydrogen migration in the hydrogen and methane co-deposited films was also studied. In samples produced in methane atmosphere and annealed at different temperatures, the hydrogen concentration level decreases in the bulk, with more pronounced release at the surface region. In the case of coatings deposited by a methane ion beam, the H level also decreases with increasing

Hydrogen from catalytic reforming of biomass-derived hydrocarbons in liquid water

Science.gov (United States)

Cortright, R. D.; Davda, R. R.; Dumesic, J. A.

2002-08-01

Concerns about the depletion of fossil fuel reserves and the pollution caused by continuously increasing energy demands make hydrogen an attractive alternative energy source. Hydrogen is currently derived from nonrenewable natural gas and petroleum, but could in principle be generated from renewable resources such as biomass or water. However, efficient hydrogen production from water remains difficult and technologies for generating hydrogen from biomass, such as enzymatic decomposition of sugars, steam-reforming of bio-oils and gasification, suffer from low hydrogen production rates and/or complex processing requirements. Here we demonstrate that hydrogen can be produced from sugars and alcohols at temperatures near 500K in a single-reactor aqueous-phase reforming process using a platinum-based catalyst. We are able to convert glucose-which makes up the major energy reserves in plants and animals-to hydrogen and gaseous alkanes, with hydrogen constituting 50% of the products. We find that the selectivity for hydrogen production increases when we use molecules that are more reduced than sugars, with ethylene glycol and methanol being almost completely converted into hydrogen and carbon dioxide. These findings suggest that catalytic aqueous-phase reforming might prove useful for the generation of hydrogen-rich fuel gas from carbohydrates extracted from renewable biomass and biomass waste streams.

Determination of Hydrogen and Carbon contents in crude oil and Petroleum fractions by NMR Spectroscopy

International Nuclear Information System (INIS)

Khadim, Mohammad A.; Wolny, R.A.; Al-Dhuwaihi, Abdullah S.; Al-Hajri, E.A.; Al-Ghamdi, M.A.

2003-01-01

Proton and carbon-13 NMR spectroscopic methods were developed for determining hydrogen and carbon contents in petroleum products. These methods are applicable to a wide of petroleum streams. A new reference standard, bis (trimethylsilyl) methane, BTMSM, is introduced fro both proton and carbon-13 NMR for the first time, which offers several advantages over those customarily employed. These methods are important for the calculation of the mass balance and hydrogen consumption in pilot plant studies. Unlike the ASTM D-5291 combustion method, the NMR methods also allow for the measurement of hydrogen and carbon content in low boiling fractions and those containing hydrogen as low as 1%. The NMR methods can also determine aromatic and aliphatic hydrogens carbons in a given sample without additional experimentation. The precision and accuracy of the newly developed NMR methods are compared with those of currently employed ASTM D-5291 combustion method. Using the proton NMR method, hydrogen content was determined in fifteen model compounds and sixty-eight petroleum fractions. The NMR and ASTM methods show an agreement within +5%for 48 out of a total number of 68 oil fractions. Using carbon-13 NMR, the carbon content was determined for four representative compounds and three fractions of crude oil. Both carbon-13 NMR and ASTM methods give comparable carbon content in model compounds and crude oil fractions. (author)

Hydrogen storage in sonicated carbon materials

NARCIS (Netherlands)

Hirscher, M.; Becher, M.; Haluska, M.; Dettlaff-Weglikowska, U.; Quintel, A.; Duesberg, G.S.; Choi, Y.J.; Downes, P.; Hulman, M.; Roth, S.; Stepanek, I.; Bernier, P.

2001-01-01

The hydrogen storage in purified single-wall carbon nanotubes (SWNTs), graphite and diamond powder was investigated at room temperature and ambient pressure. The samples were sonicated in 5 M HNO3 for various periods of time using an ultrasonic probe of the alloy Ti-6Al-4V. The goal of this

40 CFR 415.330 - Applicability; description of the carbon monoxide and by-product hydrogen production subcategory.

Science.gov (United States)

2010-07-01

... carbon monoxide and by-product hydrogen production subcategory. 415.330 Section 415.330 Protection of... MANUFACTURING POINT SOURCE CATEGORY Carbon Monoxide and By-Product Hydrogen Production Subcategory § 415.330 Applicability; description of the carbon monoxide and by-product hydrogen production subcategory. The provisions...

Hydrogen role in a carbon-free energy mix

International Nuclear Information System (INIS)

2014-02-01

Among the energy storage technologies under development today, there is today an increasing interest towards the hydrogen-based ones. Hydrogen generation allows to store electricity, while its combustion can supply electrical, mechanical or heat energy. The French Atomic Energy Commission (CEA) started to work on hydrogen technologies at the end of the 1990's in order to reinforce its economical interest. The development of these technologies is one of the 34 French industrial programs presented in September 2013 by the French Minister of productive recovery. This paper aims at identifying the hydrogen stakes in a carbon-free energy mix and at highlighting the remaining technological challenges to be met before reaching an industrial development level

Study on hydrogen transfer in coal liquefaction by tritium and carbon-14 tracers

International Nuclear Information System (INIS)

Nitoh, Osamu; Kabe, Toshiaki; Kabe, Yaeko.

1985-01-01

For the analysis of mechanism of hydrogenation and cracking of coal, the liquefaction of Taiheiyo coal using tritium labeled gaseous hydrogen and tritium labeled tetralin with small amounts of carbon-14 labeled naphthalene has been studied. Taiheiyo coal(25g) was thermally decomposed in tetralin or naphthalene solvent(75g) at 400--440 0 C under the initial hydrogen pressure of 5.9MPa for 30min with Ni-Mo-Al 2 O 3 catalyst(0--5g). The reaction mixture in an autoclave was separated by filtration, distillation and solvent extraction. Produced gas, oils and the solvent were analyzed by gas chromatography. The tritium and carbon-14 contents of separated reaction products were measured with a liquid scintilation counter to study the hydrogen transfer mechanism. The distribution of reaction products and the amount of hydrogen transfer from gas or solvent to the products were also determined. In hydrogen donor solvent such as tetralin, the coal liquefaction yield was independent from the catalyst, but the catalyst was effective in hydrocracking of preasphaltene and asphaltene. In naphthalene solvent, the coal liquefaction reaction hardly occured in the absence of the catalyst, because hydrogen transfer from both the solvent and gaseous hydrogen was scarce. Tritium distribution in the reaction products showed that complicated hydrogen exchange reactions between gaseous hydrogen, coal liquids and solvent came out by the presence of coal liquids and catalyst. The very small amounts of carbon-14 transferred to the liquefaction products showed that carbon exchange or transfer between solvent and coal did not take place. (author)

Hydrogen gains further momentum

International Nuclear Information System (INIS)

Anon.

2017-01-01

As first industrial production projects should become a reality in the next few years, hydrogen as a source of energy will find important applications with mobility, which momentum is rapid and irresistible. Next steps will be the (large capacity) storage of hydrogen associated to power-to-gas systems and the generalization of renewable energies. This document presents 5 articles, which themes are: Description and explanation of the process of hydrogen production; Presentation of the H2V project for the construction, in Normandy, of the first operational industrial hydrogen production plant using electric power 100 pc generated by renewable energies; The conversion of electric power from renewable energies through hydrogen storage and fuel cells for buildings applications (Sylfen project); The development of a reversible fuel cell at Mines-Paris Tech University, that will be adapted to the storage of renewable electric power; Hydrogen as a lever for the development of zero-emission vehicles, from trucks to cars and bicycles

Renewable Methane Generation from Carbon Dioxide and Sunlight.

Science.gov (United States)

Steinlechner, Christoph; Junge, Henrik

2018-01-02

The direct approach: Methane is a potential key player in the world's transition to a more sustainable energy future. The direct conversion of carbon dioxide into methane is highly desirable to lower the concentration of CO 2 in the atmosphere and also to store renewable energy. This Highlight describes the first homogeneous system for the light-driven conversion of CO 2 into CH 4 . © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electrospun zeolite-templated carbon composite fibres for hydrogen storage applications

CSIR Research Space (South Africa)

Annamalai, Perushini

2017-01-01

Full Text Available -defined hierarchical pore structure. The study involved encapsulation of highly porous zeolite-templated carbon (ZTC) into electrospun fibres and testing of the resulting composites for hydrogen storage. The hydrogen storage capacity of the composite fibres was 1...

Performance of carbon-based hot frit substrates: I, Low pressure helium and hydrogen testing

International Nuclear Information System (INIS)

Barletta, R.; Adams, J.; Svandrlik, J.; Powell, J.R.

1993-07-01

The performance of various carbon-based materials in flowing, high-temperature helium and hydrogen is described. These materials which are candidate hot frit substrates for possible application in a PBR include various grades of graphite, carbon-carbon and vitreous carbon. Vitreous carbon showed extremely good performance in helium, while that of the various graphite grades was quite variable and, in some cases, poor. Purified grades performed better than unpurified grades, but in all cases large sample-to-sample variations in weight loss were observed. For carbon-carbon samples, the performance was intermediate. Since the weight loss in these samples was in large measure due to the loss of the densification media, improvements in the performance of carbon-carbon may be possible. With respect to the performance in hydrogen, high weight losses were observed, re-enforcing the need for coating carbon-based materials for service in a flowing hydrogen environment

Direct measurements of adsorption heats of hydrogen on nano-porous carbons

International Nuclear Information System (INIS)

Akihiko Matsumoto; Kazumasa Yamamoto; Tomoyuki Miyata

2005-01-01

Since a exciting report of hydrogen storage in single-walled carbon nano-tubes by Dillon and his colleagues, nano-porous carbon materials, such as carbon nano-tubes, carbon nano-horns and micro-porous activated carbon, have attracted considerable attention as hydrogen storage materials. Adsorption plays a predominating role in the hydrogen storage process on solid surfaces. The adsorption is a spontaneous process, which is caused by interaction between gas molecules and surface, hence, it is always exothermic process and observed as adsorption heats. For this reason, direct measurement of the adsorption heats by adsorption micro-calorimetry would provide quantitative information on the strength of adsorption interaction and the adsorption mechanism. However, the adsorption amounts of hydrogen on carbon materials are far less than those of condensable vapors near room temperature due to low critical temperature of hydrogen (33.2 K), therefore, the adsorption heats can not be determined accurately at conventional measurement conditions near room temperature and the atmospheric pressure. This contribution reports the calorimetric characterization of hydrogen adsorption on nano-porous carbon materials at low temperature and high-pressure conditions. The high-pressure adsorption apparatus consists of a volumetric adsorption line connected to a twin-conduction type microcalorimeter. Activated carbon fibers (ACF, Ad'all Co.) of different micro-pore sizes (Table 1) were used as model adsorbents. Each ACF has slit-shaped micropores of uniform size. The adsorption isotherms and differential heats of adsorption at high-pressure region from 0 to 10 MPa were simultaneously measured at isothermal condition from 203 to 298 K. The adsorption isotherms on ACF were of Henry type regardless of adsorption temperature and pore width; the uptakes increased linearly with equilibrium pressure. The adsorption isotherm at lower sorption temperature tended to show higher sorptivity. The

Developpement d'un modele thermodynamique pour les cristallites de coke: Application aux systems carbone-hydrogene et carbone-soufre

Science.gov (United States)

Ouzilleau, Philippe

cristallite size parameters La (diameter of the crystallite) and Lc (height of the crystallite). The use of the Compound Energy Formalism is necessary to establish the methodology of the present model. Globally, the planar structure of the crystallites is divided into three sublattices on which individual chemical species are assumed to mix randomly. Appropriate thermodynamic paths are used to define the relative enthalpies and absolute entropies of these chemical species. The relative enthalpy and absolute entropy of the coke crystallites are derived for various values of La in the carbon/hydrogen and carbon/sulfur chemical systems. For the carbon/hydrogen system, the model parameters are based on the known values for the entropy of formation of simple hydrogenous organic compounds in the gaseous phase and known carbon/hydrogen bond enthalpies. Also, additional enthalpic properties of coke crystallites and graphitic structures are required for the definition of the thermodynamic paths (for example, the enthalpy associated with the delocalization of one electron in graphitic structures). Results for the carbon/hydrogen system are compared to experiments concerning the dehydrogenation of various cokes. A very satisfying agreement is obtained between the dehydrogenation curves predictively calculated by the model and the reported experimental results (obtained using slow heating rates). Most of the hydrogen content of coke crystallites (this content does not inclue the hydrogen in the condensed volatile matter phase) is predicted to leave the crystalline structure for temperatures between 1100 and 1300 K. Also, experimental measurements of the Gibbs energy of coke relative to graphite are reported. These measurements were obtained using a solid state electrochemical technique. A stabiliy of approximately 900 J g-1, relative to graphite, is reported for temperatures between 950 and 1250 K and for a crystallite size La of ˜10 nm. This value is in excellent agreement with the

S.1269: This Act may be cited as the Renewable Hydrogen Energy Research and Development Act of 1991, introduced in the Senate of the United States, One Hundred Second Congress, First Session, June 11, 1991

International Nuclear Information System (INIS)

Anon.

1991-01-01

The bill would require the Secretary of Energy to expedite the development of hydrogen derived from renewable energy sources as an alternative energy system for residential, industrial, utility, and motor vehicle use. The purposes of this bill are to reduce the US dependence on imported oil; accelerate the development of renewable hydrogen; accelerate research and development programs on components of a renewable hydrogen energy system; reduce emissions of greenhouse gases, acid rain, precursors to smog, and other air pollution; and establish industry and government cost shared projects to speed the development of renewable hydrogen energy systems

Renewable Hydrogen: Technology Review and Policy Recommendations for State-Level Sustainable Energy Futures

OpenAIRE

Lipman, Timothy; Edwards, Jennifer Lynn; Brooks, Cameron

2006-01-01

Hydrogen is emerging beyond its conventional role as an additive component for gasoline production, chemical and fertilizer manufacture, and food production to become a promising fuel for transportation and stationary power. Hydrogen offers a potentially unmatched ability to deliver a de-carbonized energy system, thereby addressing global climate change concerns, while simultaneously improving local air quality and reducing dependence on imported fossil fuels. This "trifecta" of potential ben...

Nanoconfinement in activated mesoporous carbon of calcium borohydride for improved reversible hydrogen storage.

Science.gov (United States)

Comănescu, Cezar; Capurso, Giovanni; Maddalena, Amedeo

2012-09-28

Mesoporous carbon frameworks were synthesized using the soft-template method. Ca(BH(4))(2) was incorporated into activated mesoporous carbon by the incipient wetness method. The activation of mesoporous carbon was necessary to optimize the surface area and pore size. Thermal programmed absorption measurements showed that the confinement of this borohydride into carbon nanoscaffolds improved its reversible capacity (relative to the reactive portion) and performance of hydrogen storage compared to unsupported borohydride. Hydrogen release from the supported hydride started at a temperature as low as 100 °C and the dehydrogenation rate was fast compared to the bulk borohydride. In addition, the hydrogen pressure necessary to regenerate the borohydride from the dehydrogenation products was reduced.

2015 Renewable Energy Data Book

Energy Technology Data Exchange (ETDEWEB)

Beiter, Philipp [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tian, Tian [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2016-11-01

The Renewable Energy Data Book for 2015 provides facts and figures on energy and electricity use, renewable electricity in the United States, global renewable energy development, wind power, solar power, geothermal power, biopower, hydropower, marine and hydrokinetic power, hydrogen, renewable fuels, and clean energy investment.

2015 Renewable Energy Data Book

Energy Technology Data Exchange (ETDEWEB)

Beiter, Philipp; Tian, Tian

2016-11-01

The 2015 Renewable Energy Data Book provides facts and figures on energy and electricity use, renewable electricity in the United States, global renewable energy development, wind power, solar power, geothermal power, biopower, hydropower, marine and hydrokinetic power, hydrogen, renewable fuels, and clean energy investment.

2014 Renewable Energy Data Book

Energy Technology Data Exchange (ETDEWEB)

Beiter, Philipp

2015-11-01

The Renewable Energy Data Book for 2014 provides facts and figures on energy and electricity use, renewable electricity in the United States, global renewable energy development, wind power, solar power, geothermal power, biopower, hydropower, marine and hydrokinetic power, hydrogen, renewable fuels, and clean energy investment.

2016 Renewable Energy Data Book

Energy Technology Data Exchange (ETDEWEB)

2017-12-29

The 2016 Renewable Energy Data Book provides facts and figures on energy and electricity use, renewable electricity in the United States, global renewable energy development, wind power, solar power, geothermal power, biopower, hydropower, marine and hydrokinetic power, hydrogen, renewable fuels, and clean energy investment.

Interaction of hydrogen in carbon matrix with impurities of nickel

International Nuclear Information System (INIS)

Gervasoni, L L; Segui, S

2012-01-01

This work aims to define general criteria to allow theoretical and experimental design of new materials with high hydrogen content, with a view to their potential application as moderators in reactors at high temperatures and hydrogen storage materials. To this end we study the effects of Ni impurities on the properties of pure carbon (slabs as well as nanoparticles and gels) in order to analyze the thermodynamical characteristics, and improve the behavior of alloys for Ni-metal hydride rechargeable batteries. These elements are chosen because they have a wide range of solubility of hydrogen, which from the technological point of view makes them important candidates for the search for new materials. Our results show that this kind of carbon material could be used as support for hydrogen storage improving the screening charge density and the density of available states, as analyzed by the authors in previous works (author)

Biological fermentative hydrogen production from olive pulp at 35 degrees C

Energy Technology Data Exchange (ETDEWEB)

Koutrouli, E.C.; Gavala, H.N.; Skiadas, I.V.; Lyberatos, G. [Patras Univ., Patras (Greece). Dept. of Chemical Engineering

2004-07-01

In response to energy security and environmental concerns, there is renewed interest in the use of hydrogen gas as a renewable energy source. However, many processes for generating hydrogen are extremely energy intensive and costly. This study focused on biological production of hydrogen from wastewater or other biomass. Photosynthetic and fermentation processes were outlined, but the main focus of this paper was on continuous anaerobic fermentation of low cost substrates such as olive pulp at 35 degrees C. This process is linked to the acidogenic stage of anaerobic digestion where carbohydrates are the preferred carbon source. Volatile fatty acids and alcohols are produced simultaneously with the hydrogen gas. An added advantage is that the effluent from the fermentation process can be further used by methanogenesis due to its rich organic acids content. Batch experiments with olive pulp resulted in 2.5 mmole of hydrogen per gram of total carbohydrates. It was noted that more research is required to maximize hydrogen production in a continuous process. It was suggested that hydrogen production could be optimized through hydrolysis of the non-soluble carbohydrates. This could be accomplished through physicochemical or biological pretreatments. 7 refs., 3 tabs., 1 fig.

The role of electricity storage and hydrogen technologies in enabling global low-carbon energy transitions

OpenAIRE

McPherson, M.; Johnson, N.; Strubegger, M.

2018-01-01

Previous studies have noted the importance of electricity storage and hydrogen technologies for enabling large-scale variable renewable energy (VRE) deployment in long-term climate change mitigation scenarios. However, global studies, which typically use integrated assessment models, assume a fixed cost trajectory for storage and hydrogen technologies; thereby ignoring the sensitivity of VRE deployment and/or mitigation costs to uncertainties in future storage and hydrogen technology costs. Y...

Hydrogen-bond acidic functionalized carbon nanotubes (CNTs) with covalently-bound hexafluoroisopropanol groups

Energy Technology Data Exchange (ETDEWEB)

Fifield, Leonard S.; Grate, Jay W.

2010-06-01

Fluorinated hydrogen-bond acidic groups are directly attached to the backbone of single walled carbon nanotubes (SWCNTs) without the introduction of intermediate electron donating surface groups. Hexafluoroalcohol functional groups are exceptionally strong hydrogen bond acids, and are added to the nanotube surface using the aryl diazonium approach to create hydrogen-bond acidic carbon nanotube (CNT) surfaces. These groups can promote strong hydrogen-bonding interactions with matrix materials in composites or with molecular species to be concentrated and sensed. In the latter case, this newly developed material is expected to find useful application in chemical sensors and in CNT-based preconcentrator devices for the detection of pesticides, chemical warfare agents and explosives.

Hydrogen adsorption on N-decorated single wall carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

Rangel, Eduardo [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 20-364, Codigo Postal 01000, Mexico D.F. (Mexico); Ruiz-Chavarria, Gregorio [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 20-364, Codigo Postal 01000, Mexico D.F. (Mexico); Departamento de Fisica, Facultad de Ciencias, Universidad Nacional Autonoma de Mexico Ciudad Universitaria, Codigo Postal 04510, Mexico D.F. (Mexico); Magana, L.F., E-mail: fernando@fisica.unam.m [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apartado Postal 20-364, Codigo Postal 01000, Mexico D.F. (Mexico); Arellano, J.S. [Departamento de Ciencias Basicas, Universidad Autonoma Metropolitana, Unidad Azcapotzalco. Avenida San Pablo No. 180, Col. Reynosa Tamaulipas Codigo Postal 02200, Mexico D.F. (Mexico)

2009-07-06

Using density functional theory and molecular dynamics we found that N-decorated single walled (8,0) carbon nanotubes are potential high capacity hydrogen storage media. This system could store up to 6.0 wt% hydrogen at 300 K and ambient pressure, with average adsorption energy of -80 meV/(H{sub 2}). Nitrogen coverage was C{sub 8}N.

Hydrogen adsorption on N-decorated single wall carbon nanotubes

International Nuclear Information System (INIS)

Rangel, Eduardo; Ruiz-Chavarria, Gregorio; Magana, L.F.; Arellano, J.S.

2009-01-01

Using density functional theory and molecular dynamics we found that N-decorated single walled (8,0) carbon nanotubes are potential high capacity hydrogen storage media. This system could store up to 6.0 wt% hydrogen at 300 K and ambient pressure, with average adsorption energy of -80 meV/(H 2 ). Nitrogen coverage was C 8 N.

Hydrogen storage in nanoporous carbon materials: myth and facts.

Science.gov (United States)

Kowalczyk, Piotr; Hołyst, Robert; Terrones, Mauricio; Terrones, Humberto

2007-04-21

We used Grand canonical Monte Carlo simulation to model the hydrogen storage in the primitive, gyroid, diamond, and quasi-periodic icosahedral nanoporous carbon materials and in carbon nanotubes. We found that none of the investigated nanoporous carbon materials satisfy the US Department of Energy goal of volumetric density and mass storage for automotive application (6 wt% and 45 kg H(2) m(-3)) at considered storage condition. Our calculations indicate that quasi-periodic icosahedral nanoporous carbon material can reach the 6 wt% at 3.8 MPa and 77 K, but the volumetric density does not exceed 24 kg H(2) m(-3). The bundle of single-walled carbon nanotubes can store only up to 4.5 wt%, but with high volumetric density of 42 kg H(2) m(-3). All investigated nanoporous carbon materials are not effective against compression above 20 MPa at 77 K because the adsorbed density approaches the density of the bulk fluid. It follows from this work that geometry of carbon surfaces can enhance the storage capacity only to a limited extent. Only a combination of the most effective structure with appropriate additives (metals) can provide an efficient storage medium for hydrogen in the quest for a source of "clean" energy.

Hydrogen delivery technology rRoadmap

Energy Technology Data Exchange (ETDEWEB)

None, None

2005-11-01

Hydrogen holds the long-term potential to solve two critical problems related to the energy infrastructure: U.S. dependence on foreign oil and U.S. emissions of greenhouse gases and pollutants. The U.S. transportation sector is almost completely reliant on petroleum, over half of which is currently imported, and tailpipe emissions remain one of the country’s key air quality concerns. Fuel cell vehicles operating on hydrogen produced from domestically available resources – including renewable resources, coal with carbon sequestration, or nuclear energy – would dramatically decrease greenhouse gases and other emissions, and would reduce dependence on oil from politically volatile regions of the world. Clean, domestically-produced hydrogen could also be used to generate electricity in stationary fuel cells at power plants, further extending national energy and environmental benefits.

Constraints of intermittent renewable energies on the management of the energy mix

International Nuclear Information System (INIS)

Percebois, J.

2017-01-01

It appears that variable renewable energies like wind energy or solar energy will have to play an important role in future energy mixes but today their place is limited by the impossibility of storing energy in great scale. In Europe wind energy and solar energy have been developed through incentive policies that have proposed guaranteed tariffs far higher than prices fixed by the energy market, the difference being paid by consumers through taxes. Now the growing importance of renewable energies implies reforming the electricity market. In France the reduction of the share of nuclear energy in power production to give more room for renewable energies is a nonsense because it means replacing a low-cost low-carbon energy by expensive low-carbon energies. Nuclear technologies are not frozen and will evolve over time in terms of more safety, more flexibility to meet the power demand and becoming less centralized to be used in new fields like urban heating or hydrogen production. (A.C.)

Dynamic response of a carbon nanotube-based rotary nano device with different carbon-hydrogen bonding layout

Energy Technology Data Exchange (ETDEWEB)

Yin, Hang [College of Water Resources and Architectural Engineering, Northwest A& F University, Yangling 712100 (China); Cai, Kun, E-mail: caikun1978@163.com [College of Water Resources and Architectural Engineering, Northwest A& F University, Yangling 712100 (China); Wan, Jing [College of Water Resources and Architectural Engineering, Northwest A& F University, Yangling 712100 (China); Gao, Zhaoliang, E-mail: coopcg@163.com [Institute of Soil and Water Conservation, Northwest A& F University, Yangling, 712100 (China); Chen, Zhen [State Key Laboratory of Structural Analysis for Industrial Equipment, Department of Engineering Mechanics, Faculty of Vehicle Engineering and Mechanics, Dalian University of Technology, Dalian 116024 (China)

2016-03-01

Graphical abstract: - Highlights: • The rotational transmission performance of a rotational transmission system (RTS) with different types of C−H bonding layouts on the edge of motor and rotor is investigated using MD simulation method. • The L–J interaction between covalently bonded hydrogen atoms and sp1 carbon atoms is too weak to support a stable rotational transmission when only the motor or rotor has bonded hydrogen atoms. • When both the motor and rotor have the same C−H bonding layout on their adjacent ends, a stable output rotational speed of rotor can be obtained. • A low input rotational speed (e.g., 100 GHz) would lead to a synchronous rotational transmission if the system has (+0.5H) C−H bonding layout. - Abstract: In a nano rotational transmission system (RTS) which consists of a single walled carbon nanotube (SWCNT) as the motor and a coaxially arranged double walled carbon nanotube (DWCNT) as a bearing, the interaction between the motor and the rotor in bearing, which has great effects on the response of the RTS, is determined by their adjacent edges. Using molecular dynamics (MD) simulation, the interaction is analyzed when the adjacent edges have different carbon-hydrogen (C−H) bonding layouts. In the computational models, the rotor in bearing and the motor with a specific input rotational speed are made from the same armchair SWCNT. Simulation results demonstrate that a perfect rotational transmission could happen when the motor and rotor have the same C−H bonding layout on their adjacent ends. If only half or less of the carbon atoms on the adjacent ends are bonded with hydrogen atoms, the strong attraction between the lower speed (100 GHz) motor and rotor leads to a synchronous rotational transmission. If only the motor or the rotor has C−H bonds on their adjacent ends, no rotational transmission happens due to weak interaction between the bonded hydrogen atoms on one end with the sp{sup 1} bonded carbon atoms on the other

Minimizing fouling at hydrogenated conical-tip carbon electrodes during dopamine detection in vivo.

Science.gov (United States)

Chandra, Shaneel; Miller, Anthony D; Bendavid, Avi; Martin, Philip J; Wong, Danny K Y

2014-03-04

In this paper, physically small conical-tip carbon electrodes (∼2-5 μm diameter and ∼4 μm axial length) were hydrogenated to develop a probe capable of withstanding fouling during dopamine detection in vivo. Upon hydrogenation, the resultant hydrophobic sp(3) carbon surface deters adsorption of amphiphilic lipids, proteins, and peptides present in extracellular fluid and hence minimizes electrode fouling. These hydrogenated carbon electrodes showed a 35% decrease in sensitivity but little change in the limit of detection for dopamine over a 7-day incubation in a synthetic laboratory solution containing 1.0% (v/v) caproic acid (a lipid), 0.1% (w/v) bovine serum albumin and 0.01% (w/v) cytochrome C (both are proteins), and 0.002% (w/v) human fibrinopeptide B (a peptide). Subsequently, during dopamine detection in vivo, over 70% of the dopamine oxidation current remained after the first 30 min of a 60-min experiment, and at least 50% remained over the next half-period at the hydrogenated carbon electrodes. On the basis of these results, an initial average electrode surface fouling rate of 1.2% min(-1) was estimated, which gradually declined to 0.7% min(-1). These results support minimal fouling at hydrogenated carbon electrodes applied to dopamine detection in vivo.

New Pathways and Metrics for Enhanced, Reversible Hydrogen Storage in Boron-Doped Carbon Nanospaces

Energy Technology Data Exchange (ETDEWEB)

Pfeifer, Peter [University of Missouri; Wexler, Carlos [University of Missouri; Hawthorne, M. Frederick [University of Missouri; Lee, Mark W. [University of Missouri; Jalistegi, Satish S. [University of Missouri

2014-08-14

This project, since its start in 2007—entitled “Networks of boron-doped carbon nanopores for low-pressure reversible hydrogen storage” (2007-10) and “New pathways and metrics for enhanced, reversible hydrogen storage in boron-doped carbon nanospaces” (2010-13)—is in support of the DOE's National Hydrogen Storage Project, as part of the DOE Hydrogen and Fuel Cells Program’s comprehensive efforts to enable the widespread commercialization of hydrogen and fuel cell technologies in diverse sectors of the economy. Hydrogen storage is widely recognized as a critical enabling technology for the successful commercialization and market acceptance of hydrogen powered vehicles. Storing sufficient hydrogen on board a wide range of vehicle platforms, at energy densities comparable to gasoline, without compromising passenger or cargo space, remains an outstanding technical challenge. Of the main three thrust areas in 2007—metal hydrides, chemical hydrogen storage, and sorption-based hydrogen storage—sorption-based storage, i.e., storage of molecular hydrogen by adsorption on high-surface-area materials (carbons, metal-organic frameworks, and other porous organic networks), has emerged as the most promising path toward achieving the 2017 DOE storage targets of 0.055 kg H2/kg system (“5.5 wt%”) and 0.040 kg H2/liter system. The objective of the project is to develop high-surface-area carbon materials that are boron-doped by incorporation of boron into the carbon lattice at the outset, i.e., during the synthesis of the material. The rationale for boron-doping is the prediction that boron atoms in carbon will raise the binding energy of hydro- gen from 4-5 kJ/mol on the undoped surface to 10-14 kJ/mol on a doped surface, and accordingly the hydro- gen storage capacity of the material. The mechanism for the increase in binding energy is electron donation from H2 to electron-deficient B atoms, in the form of sp2 boron-carbon bonds. Our team is proud to have

Hydrogen production from sewage sludge by steam gasification

Energy Technology Data Exchange (ETDEWEB)

Aye, L.; Klinkajorn, P. [Melbourne Univ. International Technologies Centre, Melbourne, Victoria (Australia). Dept. of Civil and Environmental Engineering

2006-07-01

Because of the shortage of energy sources in the near future, renewable energy, such as biomass, has become an important source of energy. One of the most common approaches for producing gaseous fuels from biomass is gasification. The main product gases of gasification are hydrogen, carbon monoxide, methane and low molecular weight hydrocarbons. Because of the capability of very low emission at the point of use, the interest in using hydrogen for electrical power generation and in electric-vehicles has been increasing. Hydrogen from biomass steam gasification (SG) is a net zero green house gas emission fuel. Sewage sludge (SS) has a potential to produce hydrogen-rich gaseous fuel. Therefore, hydrogen production from sewage sludge may be a solution for cleaner fuel and the sewage sludge disposal problem. This paper presented the results of a computer model for SSSG by using Gibbs free energy minimization (GFEM) method. The computer model developed was used to determine the hydrogen production limits for various steam to biomass ratios. The paper presented an introduction to renewable energy and gasification and discussed the Gibbs free energy minimization method. The study used a RAND algorithm. It presented the computer model input parameters and discussed the results of the stoichiometric analysis and Gibbs free energy minimization. The energy requirement for hydrogen production was also presented. 17 refs., 1 tab., 6 figs.

Carbon and hydrogen isotope fractionation during aerobic biodegradation of quinoline and 3-methylquinoline.

Science.gov (United States)

Cui, Mingchao; Zhang, Wenbing; Fang, Jun; Liang, Qianqiong; Liu, Dongxuan

2017-08-01

Compound-specific isotope analysis has been used extensively to investigate the biodegradation of various organic pollutants. To date, little isotope fractionation information is available for the biodegradation of quinolinic compounds. In this study, we report on the carbon and hydrogen isotope fractionation during quinoline and 3-methylquinoline aerobic microbial degradation by a Comamonas sp. strain Q10. Degradation of quinoline and 3-methylquinoline was accompanied by isotope fractionation. Large hydrogen and small carbon isotope fractionation was observed for quinoline while minor carbon and hydrogen isotope fractionation effects occurred for 3-methylquinoline. Bulk carbon and hydrogen enrichment factors (ε bulk ) for quinoline biodegradation were -1.2 ± 0.1 and -38 ± 1‰, respectively, while -0.7 ± 0.1 and -5 ± 1‰ for 3-methylquinoline, respectively. This reveals a potential advantage for employing quinoline as the model compound and hydrogen isotope analysis for assessing aerobic biodegradation of quinolinic compounds. The apparent kinetic isotope effects (AKIE C ) values of carbon were 1.008 ± 0.0005 for quinoline and 1.0048 ± 0.0005 for 3-methylquinoline while AKIE H values of hydrogen of 1.264 ± 0.011 for quinoline and 1.0356 ± 0.0103 for 3-methylquinoline were obtained. The combined evaluation of carbon and hydrogen isotope fractionation yields Λ values (Λ = Δδ 2 H/Δδ 13 C ≈ εH bulk /εC bulk ) of 29 ± 2 for quinoline and 8 ± 2 for 3-methylquinoline. The results indicate that the substrate specificity may have a significant influence on the isotope fractionation for the biodegradation of quinolinic compounds. The substrate-specific isotope enrichment factors would be important for assessing the behavior and fate of quinolinic compounds in the environment.

The role of destabilization of palladium hydride in the hydrogen uptake of Pd-containing activated carbons

International Nuclear Information System (INIS)

Bhat, V V; Contescu, C I; Gallego, N C

2009-01-01

This paper reports on differences in stability of Pd hydride phases in palladium particles with various degrees of contact with microporous carbon supports. A sample containing Pd embedded in activated carbon fibre (2 wt% Pd) was compared with commercial Pd nanoparticles deposited on microporous activated carbon (3 wt% Pd) and with support-free nanocrystalline palladium. The morphology of the materials was characterized by electron microscopy, and the phase transformations were analysed over a large range of hydrogen partial pressures (0.003-10 bar) and at several temperatures using in situ x-ray diffraction. The results were verified with volumetric hydrogen uptake measurements. Results indicate that higher degrees of Pd-carbon contacts for Pd particles embedded in a microporous carbon matrix induce efficient 'pumping' of hydrogen out of β- PdH x . It was also found that thermal cleaning of carbon surface groups prior to exposure to hydrogen further enhances the hydrogen pumping power of the microporous carbon support. In brief, this study highlights that the stability of β- PdH x phase supported on carbon depends on the degree of contact between Pd and carbon and on the nature of the carbon surface.

Renewable energy, carbon emissions, and economic growth in 24 Asian countries: evidence from panel cointegration analysis.

Science.gov (United States)

Lu, Wen-Cheng

2017-11-01

This article aims to investigate the relationship among renewable energy consumption, carbon dioxide (CO 2 ) emissions, and GDP using panel data for 24 Asian countries between 1990 and 2012. Panel cross-sectional dependence tests and unit root test, which considers cross-sectional dependence across countries, are used to ensure that the empirical results are correct. Using the panel cointegration model, the vector error correction model, and the Granger causality test, this paper finds that a long-run equilibrium exists among renewable energy consumption, carbon emission, and GDP. CO 2 emissions have a positive effect on renewable energy consumption in the Philippines, Pakistan, China, Iraq, Yemen, and Saudi Arabia. A 1% increase in GDP will increase renewable energy by 0.64%. Renewable energy is significantly determined by GDP in India, Sri Lanka, the Philippines, Thailand, Turkey, Malaysia, Jordan, United Arab Emirates, Saudi Arabia, and Mongolia. A unidirectional causality runs from GDP to CO 2 emissions, and two bidirectional causal relationships were found between CO 2 emissions and renewable energy consumption and between renewable energy consumption and GDP. The findings can assist governments in curbing pollution from air pollutants, execute energy conservation policy, and reduce unnecessary wastage of energy.

Dynamic Biogas Upgrading for Integration of Renewable Energy from Wind, Biomass and Solar

DEFF Research Database (Denmark)

Jurgensen, Lars

The Sabatier process is investigated as a storage scheme for renewable energy. Hydrogen derived from fluctuating renewable energy sources like wind and solar is converted to methane by the hydrogenation/methanation of carbon oxides. Biogas from anaerobic digestion is considered in this study...... as a sustainable process for electricity storage and system integration in Northern Germany, i. e. the state of Schleswig-Holstein. A feasibility study was conducted to analyze the energy system in this region and the potential for this process. Process simulation tools were used to prove the product gas...... properties and the degree of efficiency of the system. Lab-scale and bench-scale experiments where further applied to demonstrate the utilization of industrial waste water for biogas production and the general applicability of biogas in the Sabatier process....

Review of theoretical calculations of hydrogen storage in carbon-based materials

Energy Technology Data Exchange (ETDEWEB)

Meregalli, V.; Parrinello, M. [Max-Planck-Institut fuer Festkoerperforschung, Stuttgart (Germany)

2001-02-01

In this paper we review the existing theoretical literature on hydrogen storage in single-walled nanotubes and carbon nanofibers. The reported calculations indicate a hydrogen uptake smaller than some of the more optimistic experimental results. Furthermore the calculations suggest that a variety of complex chemical processes could accompany hydrogen storage and release. (orig.)

Hydrogen Production from Nuclear Energy

Science.gov (United States)

Walters, Leon; Wade, Dave

2003-07-01

During the past decade the interest in hydrogen as transportation fuel has greatly escalated. This heighten interest is partly related to concerns surrounding local and regional air pollution from the combustion of fossil fuels along with carbon dioxide emissions adding to the enhanced greenhouse effect. More recently there has been a great sensitivity to the vulnerability of our oil supply. Thus, energy security and environmental concerns have driven the interest in hydrogen as the clean and secure alternative to fossil fuels. Remarkable advances in fuel-cell technology have made hydrogen fueled transportation a near-term possibility. However, copious quantities of hydrogen must be generated in a manner independent of fossil fuels if environmental benefits and energy security are to be achieved. The renewable technologies, wind, solar, and geothermal, although important contributors, simply do not comprise the energy density required to deliver enough hydrogen to displace much of the fossil transportation fuels. Nuclear energy is the only primary energy source that can generate enough hydrogen in an energy secure and environmentally benign fashion. Methods of production of hydrogen from nuclear energy, the relative cost of hydrogen, and possible transition schemes to a nuclear-hydrogen economy will be presented.

Climate consequences of low-carbon fuels: The United States Renewable Fuel Standard

International Nuclear Information System (INIS)

Hill, Jason; Tajibaeva, Liaila; Polasky, Stephen

2016-01-01

A common strategy for reducing greenhouse gas (GHG) emissions from energy use is to increase the supply of low-carbon alternatives. However, increasing supply tends to lower energy prices, which encourages additional fuel consumption. This “fuel market rebound effect” can undermine climate change mitigation strategies, even to the point where efforts to reduce GHG emissions by increasing the supply of low-carbon fuels may actually result in increased GHG emissions. Here, we explore how policies that encourage the production of low-carbon fuels may result in increased GHG emissions because the resulting increase in energy use overwhelms the benefits of reduced carbon intensity. We describe how climate change mitigation strategies should follow a simple rule: a low-carbon fuel with a carbon intensity of X% that of a fossil fuel must displace at least X% of that fossil fuel to reduce overall GHG emissions. We apply this rule to the United States Renewable Fuel Standard (RFS2). We show that absent consideration of the fuel market rebound effect, RFS2 appears to reduce GHG emissions, but once the fuel market rebound effect is factored in, RFS2 actually increases GHG emissions when all fuel GHG intensity targets are met. - Highlights: • Low-carbon fuels partially displace petroleum via fuel market rebound effect. • Synthesis of recent analyses shows incomplete petroleum displacement by biofuels. • Fuel market rebound effect can reduce or reverse climate benefit of low-carbon fuels. • Fossil fuel displacement must exceed relative carbon footprint of a low-carbon fuel. • The Renewable Fuel Standard increases greenhouse gas emissions when mandate is met.

An Overview of Natural Gas Conversion Technologies for Co-Production of Hydrogen and Value-Added Solid Carbon Products

Energy Technology Data Exchange (ETDEWEB)

Dagle, Robert A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Dagle, Vanessa [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bearden, Mark D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Holladay, Jamelyn D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Krause, Theodore R. [Argonne National Lab. (ANL), Argonne, IL (United States); Ahmed, Shabbir [Argonne National Lab. (ANL), Argonne, IL (United States)

2017-11-16

This report was prepared in response to the U.S. Department of Energy Fuel Cell Technologies Office Congressional Appropriation language to support research on carbon-free production of hydrogen using new chemical processes that utilize natural gas to produce solid carbon and hydrogen. The U.S. produces 9-10 million tons of hydrogen annually with more than 95% of the hydrogen produced by steam-methane reforming (SMR) of natural gas. SMR is attractive because of its high hydrogen yield; but it also converts the carbon to carbon dioxide. Non-oxidative thermal decomposition of methane to carbon and hydrogen is an alternative to SMR and produces CO₂-free hydrogen. The produced carbon can be sold as a co-product, thus providing economic credit that reduces the delivered net cost of hydrogen. The combination of producing hydrogen with potentially valuable carbon byproducts has market value in that this allows greater flexibility to match the market prices of hydrogen and carbon. That is, the higher value product can subsidize the other in pricing decisions. In this report we highlight the relevant technologies reported in the literature—primarily thermochemical and plasma conversion processes—and recent research progress and commercial activities. Longstanding technical challenges include the high energetic requirements (e.g., high temperatures and/or electricity requirements) necessary for methane activation and, for some catalytic processes, the separation of solid carbon product from the spent catalyst. We assess current and new carbon product markets that could be served given technological advances, and we discuss technical barriers and potential areas of research to address these needs. We provide preliminary economic analysis for these processes and compare to other emerging (e.g., electrolysis) and conventional (e.g., SMR) processes for hydrogen production. The overarching conclusion of this study is that the cost of hydrogen can be potentially

Performance simulation of planar SOFC using mixed hydrogen and carbon monoxide gases as fuel

Energy Technology Data Exchange (ETDEWEB)

Inui, Y. [Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580 (Japan)]. E-mail: inui@eee.tut.ac.jp; Urata, A. [Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580 (Japan); Ito, N. [Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580 (Japan); Nakajima, T. [Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580 (Japan); Tanaka, T. [Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580 (Japan)

2006-08-15

The authors investigate in detail the influence of the mixing ratio of hydrogen and carbon monoxide in the fuel on the cell performance of the SOFC through numerical simulations for a single cell plate of the co-flow type planar cell. It is made clear that the cell performance is almost the same and excellent, independent of the mixing ratio of hydrogen and carbon monoxide under the nominal operating condition. The electromotive force of the hydrogen rich fuel gas is a little higher than that of the carbon monoxide rich fuel gas. The internal voltage drop in the cell decreases as the fraction of carbon monoxide becomes high. Since the value of the single cell voltage is determined by the balance of these two phenomena, the lowering of the electromotive force is dominant and the single cell voltage of the hydrogen rich fuel gas is higher when the inlet gas temperature is high, whereas the voltage drop reduction is dominant and the single cell voltage of the carbon monoxide rich fuel gas is higher when the temperature is low. The effect of the additional gases of water vapor and carbon dioxide is restricted to the single cell voltage shift, and the qualitative dependence of the single cell voltage on the inlet gas temperature is determined by the mixing ratio of hydrogen and carbon monoxide.

Performance simulation of planar SOFC using mixed hydrogen and carbon monoxide gases as fuel

International Nuclear Information System (INIS)

Inui, Y.; Urata, A.; Ito, N.; Nakajima, T.; Tanaka, T.

2006-01-01

The authors investigate in detail the influence of the mixing ratio of hydrogen and carbon monoxide in the fuel on the cell performance of the SOFC through numerical simulations for a single cell plate of the co-flow type planar cell. It is made clear that the cell performance is almost the same and excellent, independent of the mixing ratio of hydrogen and carbon monoxide under the nominal operating condition. The electromotive force of the hydrogen rich fuel gas is a little higher than that of the carbon monoxide rich fuel gas. The internal voltage drop in the cell decreases as the fraction of carbon monoxide becomes high. Since the value of the single cell voltage is determined by the balance of these two phenomena, the lowering of the electromotive force is dominant and the single cell voltage of the hydrogen rich fuel gas is higher when the inlet gas temperature is high, whereas the voltage drop reduction is dominant and the single cell voltage of the carbon monoxide rich fuel gas is higher when the temperature is low. The effect of the additional gases of water vapor and carbon dioxide is restricted to the single cell voltage shift, and the qualitative dependence of the single cell voltage on the inlet gas temperature is determined by the mixing ratio of hydrogen and carbon monoxide

The study of hydrogen electrosorption in layered nickel foam/palladium/carbon nanofibers composite electrodes

International Nuclear Information System (INIS)

Skowronski, J.M.; Czerwinski, A.; Rozmanowski, T.; Rogulski, Z.; Krawczyk, P.

2007-01-01

In the present work, the process of hydrogen electrosorption occurring in alkaline KOH solution on the nickel foam/palladium/carbon nanofibers (Ni/Pd/CNF) composite electrodes is examined. The layered Ni/Pd/CNF electrodes were prepared by a two-step method consisting of chemical deposition of a thin layer of palladium on the nickel foam support to form Ni/Pd electrode followed by coating the palladium layer with carbon nanofibers layer by means of the CVD method. The scanning electron microscope was used for studying the morphology of both the palladium and carbon layer. The process of hydrogen sorption/desorption into/from Ni/Pd as well as Ni/Pd/CNF electrode was examined using the cyclic voltammetry method. The amount of hydrogen stored in both types of composite electrodes was shown to increase on lowering the potential of hydrogen sorption. The mechanism of the anodic desorption of hydrogen changes depending on whether or not CNF layer is present on the Pd surface. The anodic peak corresponding to the removal of hydrogen from palladium is lower for Ni/Pd/CNF electrode as compared to that measured for Ni/Pd one due to a partial screening of the Pd surface area by CNF layer. The important feature of Ni/Pd/CNF electrode is anodic peak appearing on voltammetric curves at potential ca. 0.4 V more positive than the peak corresponding to hydrogen desorption from palladium. The obtained results showed that upon storing the hydrogen saturated Ni/Pd/CNF electrode at open circuit potential, diffusion of hydrogen from carbon to palladium phase occurs due to interaction between carbon fibers and Pd sites on the nickel foam support

Hydrogen and nuclear energy

International Nuclear Information System (INIS)

Duffey, R.B.; Miller, A.I.; Hancox, W.T.; Pendergast, D.R.

1999-01-01

The current world-wide emphasis on reducing greenhouse gas (GHG) emissions provides an opportunity to revisit how energy is produced and used, consistent with the need for human and economic growth. Both the scale of the problem and the efforts needed for its resolution are extremely large. We argue that GHG reduction strategies must include a greater penetration of electricity into areas, such as transportation, that have been the almost exclusive domain of fossil fuels. An opportunity for electricity to displace fossil fuel use is through electrolytic production of hydrogen. Nuclear power is the only large-scale commercially proven non-carbon electricity generation source, and it must play a key role. As a non-carbon power source, it can also provide the high-capacity base needed to stabilize electricity grids so that they can accommodate other non-carbon sources, namely low-capacity factor renewables such as wind and solar. Electricity can be used directly to power standalone hydrogen production facilities. In the special case of CANDU reactors, the hydrogen streams can be preprocessed to recover the trace concentrations of deuterium that can be re-oxidized to heavy water. World-wide experience shows that nuclear power can achieve high standards of public safety, environmental protection and commercially competitive economics, and must . be an integral part of future energy systems. (author)

Nuclear energy and its synergies with renewable energies; Le nucleaire dans ses synergies avec les renouvelables

Energy Technology Data Exchange (ETDEWEB)

Carre, F. [CEA Saclay, DEN, 91 - Gif-sur-Yvette (France); Mermilliod, N. [CEA Grenoble, Dir. de la Recherche Technologique, 38 (France); Devezeaux De Lavergne, J.G. [CEA Saclay, Dir. de l' Institut de tecchnico-economie des systemes energetiques I-tese, 91 - Gif-sur-Yvette (France); Durand, S. [CEA Grenoble, European Institute of Technology -KIC InnoEnergy, 38 (France)

2011-05-15

France has the ambition to become a world leader in both nuclear industry and in renewable energies. 3 types of synergies between nuclear power and renewable energies are highlighted. First, nuclear power can be used as a low-carbon energy to produce the equipment required to renewable energy production for instance photovoltaic cells. Secondly, to benefit from the complementary features of both energies: continuous/intermittency of the production, centralized/local production. The future development of smart grids will help to do that. Thirdly, to use nuclear energy to produce massively hydrogen from water and synthetic fuels from biomass. (A.C.)

Renewable methane generation from carbon dioxide and sunlight

Energy Technology Data Exchange (ETDEWEB)

Steinlechner, Christoph; Junge, Henrik [Leibniz Institut fuer Katalyse, Universitaet Rostock e.V., Rostock (Germany)

2018-01-02

The direct approach: Methane is a potential key player in the world's transition to a more sustainable energy future. The direct conversion of carbon dioxide into methane is highly desirable to lower the concentration of CO{sub 2} in the atmosphere and also to store renewable energy. This Highlight describes the first homogeneous system for the light-driven conversion of CO{sub 2} into CH{sub 4}. (copyright 2018 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

Light hydrogen isotopes in the single - walled carbon nano tube

International Nuclear Information System (INIS)

Khugaev, A.V.; Sultanov, R.A.; Guster, D.

2007-01-01

Full text: Progress of our understanding of the molecular hydrogen behavior in the nano tube interior open an intriguing possibility for the applications of these knowledge's to the solution of the hydrogen storage problem and light isotopes gas selectivity. That can strongly change the situation at the energy production in the world and completely change our civil life. These investigations underline the influence of the quantum effects on the properties of molecular hydrogen in the nano tube interior and it leads to the pure quantum-mechanical reformulation of the problem for the hydrogen behavior inside carbon nano tube as a problem of molecular quantum system behavior in the external field induced by the regular nano tube surface. In the present paper the molecular hydrogen behavior in the carbon nano tube was considered in the simple quantum mechanical manner. The main attention was paid to the investigation of the quantum sieving selectivity in the dependence of nano tube composition, radius and symmetry properties. For the interaction potential between hydrogen and nano tube surface was taken some phenomenological LJ(12,6) - (Lennard - Jones) potential and the external field induced by the nano tube in its interior is considered as a simple sum over the all nano tube carbon atoms. Influence of the structure of rotation (vibration) spectrum of the energy levels of diatomic molecules, such as H 2 , HD and D 2 on the final results and finite size of the nano tube along the axis of symmetry, its boundary effects is discussed in details. Thermal oscillations of nano tube surface were considered separately in the dependence of the temperature gradient along of the axis of symmetry

Energy storage applications of activated carbons: supercapacitors and hydrogen storage

OpenAIRE

Sevilla Solís, Marta; Mokaya, Robert

2014-01-01

Porous carbons have several advantageous properties with respect to their use in energy applications that require constrained space such as in electrode materials for supercapacitors and as solid state hydrogen stores. The attractive properties of porous carbons include, ready abundance, chemical and thermal stability, ease of processability and low framework density. Activated carbons, which are perhaps the most explored class of porous carbons, have been traditionally employed as catalyst s...

Co-Generation and Renewables: Solutions for a Low-Carbon Energy Future

Energy Technology Data Exchange (ETDEWEB)

NONE

2011-07-01

Co-generation and renewables: solutions for a low-carbon energy future shows that powerful synergies exist when co-generation and renewables work together. The report documents, for the first time, some of the little-known complementary aspects of the two technologies. It also re-emphasises the stand-alone benefits of each technology. Thus, decision makers can use the report as a 'one-stop shop' when they need credible information on co-generation, renewables and the possible synergies between the two. It also provides answers to policy makers' questions about the potential energy and environmental benefits of an increased policy commitment to both co-generation and renewables. Secure, reliable, affordable and clean energy supplies are fundamental to economic and social stability and development. Energy and environmental decision-makers are faced with major challenges that require action now in order to ensure a more sustainable future. More efficient use of, and cleaner primary energy sources can help to achieve this goal. Co-generation -- also known as combined heat and power (CHP) -- represents a proven, cost-effective and energy-efficient solution for delivering electricity and heat. Renewable sources provide clean and secure fuels for producing electricity and heat.

Preparation, microstructure and hydrogen sorption properties of nanoporous carbon aerogels under ambient drying

Science.gov (United States)

Tian, H. Y.; Buckley, C. E.; Mulè, S.; Paskevicius, M.; Dhal, B. B.

2008-11-01

Organic aerogels are prepared by the sol-gel method from polymerization of resorcinol with furfural. These aerogels are further carbonized in nitrogen in order to obtain their corresponding carbon aerogels (CA); a sample which was carbonized at 900 °C was also activated in a carbon dioxide atmosphere at 900 °C. The chemical reaction mechanism and optimum synthesis conditions are investigated by means of Fourier transform infrared spectroscopy and thermoanalyses (thermogravimetric/differential thermal analyses) with a focus on the sol-gel process. The carbon aerogels were investigated with respect to their microstructures, using small angle x-ray scattering (SAXS), transmission electron microscopy (TEM) and nitrogen adsorption measurements at 77 K. SAXS studies showed that micropores with a radius of gyration of adsorption showed that larger mesopores were also present. Hydrogen storage properties of the CA were also investigated. An activated sample with a Brunauer-Emmett-Teller surface area of 1539 ± 20 m2 g-1 displayed a reasonably high hydrogen uptake at 77 K with a maximum hydrogen sorption of 3.6 wt% at 2.5 MPa. These results suggest that CA are promising candidate hydrogen storage materials.

2010 Renewable Energy Data Book (Book)

Energy Technology Data Exchange (ETDEWEB)

Gelman, R.

2011-10-01

This Renewable Energy Data Book for 2010 provides facts and figures on energy in general, renewable electricity in the United States, global renewable energy development, wind power, solar energy, geothermal power, biopower, hydropower, advanced water power, hydrogen, renewable fuels, and clean energy investments.

2013 Renewable Energy Data Book (Book)

Energy Technology Data Exchange (ETDEWEB)

Esterly, S.

2014-12-01

This Renewable Energy Data Book for 2013 provides facts and figures on energy in general, renewable electricity in the United States, global renewable energy development, wind power, solar power, geothermal power, biopower, hydropower, advanced water power, hydrogen, renewable fuels, and clean energy investment.

2011 Renewable Energy Data Book (Book)

Energy Technology Data Exchange (ETDEWEB)

Gelman, R.

2012-10-01

This Renewable Energy Data Book for 2011 provides facts and figures on energy in general, renewable electricity in the United States, global renewable energy development, wind power, solar energy, geothermal power, biopower, hydropower, advanced water power, hydrogen, renewable fuels, and clean energy investments.

Ammonia inhibition on hydrogen enriched anaerobic digestion of manure under mesophilic and thermophilic conditions

DEFF Research Database (Denmark)

Wang, Han; Zhang, Yifeng; Angelidaki, Irini

2016-01-01

Capturing of carbon dioxide by hydrogen derived from excess renewable energy (e.g., wind mills) to methane in a microbially catalyzed process offers an attractive technology for biogas production and upgrading. This bioconversion process is catalyzed by hydrogenotrophic methanogens, which are kno...

Water electrolysis with a conducting carbon cloth: subthreshold hydrogen generation and superthreshold carbon quantum dot formation.

Science.gov (United States)

Biswal, Mandakini; Deshpande, Aparna; Kelkar, Sarika; Ogale, Satishchandra

2014-03-01

A conducting carbon cloth, which has an interesting turbostratic microstructure and functional groups that are distinctly different from other ordered forms of carbon, such as graphite, graphene, and carbon nanotubes, was synthesized by a simple one-step pyrolysis of cellulose fabric. This turbostratic disorder and surface chemical functionalities had interesting consequences for water splitting and hydrogen generation when such a cloth was used as an electrode in the alkaline electrolysis process. Importantly, this work also gives a new twist to carbon-assisted electrolysis. During electrolysis, the active sites in the carbon cloth allow slow oxidation of its surface to transform the surface groups from COH to COOH and so forth at a voltage as low as 0.2 V in a two-electrode system, along with platinum as the cathode, instead of 1.23 V (plus overpotential), which is required for platinum, steel, or even graphite anodes. The quantity of subthreshold hydrogen evolved was 24 mL cm(-2)  h(-1) at 1 V. Interestingly, at a superthreshold potential (>1.23 V+overpotential), another remarkable phenomenon was found. At such voltages, along with the high rate and quantity of hydrogen evolution, rapid exfoliation of the tiny nanoscale (5-7 nm) units of carbon quantum dots (CQDs) are found in copious amounts due to an enhanced oxidation rate. These CQDs show bright-blue fluorescence under UV light. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Stability and Electronic Properties of Hydrogenated Zigzag Carbon Nanotube Focused on Stone-Wales Defect

International Nuclear Information System (INIS)

Pan Li-Jun; Zhang Jie; Chen Wei-Guang; Tang Ya-Nan

2015-01-01

We present a first-principles study of the chemisorption of hydrogen on a Stone-Wales (SW) defective carbon nanotube (10,0). The investigated configurations include four configurations covering single defects and double defects. One hydrogen dimer adsorption is energetically favored on bonds shared by carbon heptagon-heptagon for configurations with the defect parallel to the tube axis compared with the carbon pentagon-hexagon sites for ones with a slanted defect. This different behavior is also demonstrated for hydrogen dimer chain adsorption, the favored site for the former ones is through the defect, which is the nearest neighbor site to defect for the latter ones. It is found that the energy band gaps of hydrogenated configurations may be enlarged or decreased by altering the adsorption site or defect position. The semiconductor-to-metal transition may occur for configurations with the defect or defects parallel to the tube axis due to low electronic localization. Our results highlight the interest of the interaction of multi-factor system by providing a detailed bond and position picture of a hydrogenated defective carbon nanotube (10,0). (paper)

Renewable Acrylonitrile Production

Energy Technology Data Exchange (ETDEWEB)

Beckham, Gregg T [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Karp, Eric M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Eaton, Todd R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sanchez i Nogue, Violeta [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Vorotnikov, Vassili [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Biddy, Mary J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Tan, Eric C [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Brandner, David [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Manker, Lorenz [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Michener, William E [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Vardon, Derek R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Bratis, Adam D [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Liu, Rongming [University of Colorado; Gill, Ryan T. [University of Colorado; Gilhespy, Michelle [Johnson Matthey Technology Centre; Skoufa, Zinovia [Johnson Matthey Technology Centre; Watson, Michael J. [Johnson Matthey Technology Centre; Fruchey, O. Stanley [MATRIC; Cywar, Robin M. [Formerly NREL

2017-12-08

Acrylonitrile (ACN) is a petroleum-derived compound used in resins, polymers, acrylics, and carbon fiber. We present a process for renewable ACN production using 3-hydroxypropionic acid (3-HP), which can be produced microbially from sugars. The process achieves ACN molar yields exceeding 90% from ethyl 3-hydroxypropanoate (ethyl 3-HP) via dehydration and nitrilation with ammonia over an inexpensive titanium dioxide solid acid catalyst. We further describe an integrated process modeled at scale that is based on this chemistry and achieves near-quantitative ACN yields (98 +/- 2%) from ethyl acrylate. This endothermic approach eliminates runaway reaction hazards and achieves higher yields than the standard propylene ammoxidation process. Avoidance of hydrogen cyanide as a by-product also improves process safety and mitigates product handling requirements.

Catalytic hydrogenation of carbon monoxide

Energy Technology Data Exchange (ETDEWEB)

Wayland, B.B.

1992-12-01

This project is focused on developing strategies to accomplish the reduction and hydrogenation of carbon monoxide to produce organic oxygenates at mild conditions. Our approaches to this issue are based on the recognition that rhodium macrocycles have unusually favorable thermodynamic values for producing a series of intermediate implicated in the catalytic hydrogenation of CO. Observations of metalloformyl complexes produced by reactions of H{sub 2} and CO, and reductive coupling of CO to form metallo {alpha}-diketone species have suggested a multiplicity of routes to organic oxygenates that utilize these species as intermediates. Thermodynamic and kinetic-mechanistic studies are used in constructing energy profiles for a variety of potential pathways, and these schemes are used in guiding the design of new metallospecies to improve the thermodynamic and kinetic factors for individual steps in the overall process. Variation of the electronic and steric effects associated with the ligand arrays along with the influences of the reaction medium provide the chemical tools for tuning these factors. Emerging knowledge of the factors that contribute to M-H, M-C and M-O bond enthalpies is directing the search for ligand arrays that will expand the range of metal species that have favorable thermodynamic parameters to produce the primary intermediates for CO hydrogenation. Studies of rhodium complexes are being extended to non-macrocyclic ligand complexes that emulate the favorable thermodynamic features associated with rhodium macrocycles, but that also manifest improved reaction kinetics. Multifunctional catalyst systems designed to couple the ability of rhodium complexes to produce formyl and diketone intermediates with a second catalyst that hydrogenates these imtermediates are promising approaches to accomplish CO hydrogenation at mild conditions.

Hydrogen Sulphide Corrosion of Carbon and Stainless Steel Alloys Immersed in Mixtures of Renewable Fuel Sources and Tested Under Co-processing Conditions

Directory of Open Access Journals (Sweden)

Gergely András

2016-10-01

Full Text Available In accordance with modern regulations and directives, the use of renewable biomass materials as precursors for the production of fuels for transportation purposes is to be strictly followed. Even though, there are problems related to processing, storage and handling in wide range of subsequent uses, since there must be a limit to the ratio of biofuels mixed with mineral raw materials. As a key factor with regards to these biomass sources pose a great risk of causing multiple forms of corrosion both to metallic and non-metallic structural materials. To assess the degree of corrosion risk to a variety of engineering alloys like low-carbon and stainless steels widely used as structural metals, this work is dedicated to investigating corrosion rates of economically reasonable engineering steel alloys in mixtures of raw gas oil and renewable biomass fuel sources under typical co-processing conditions. To model a desulphurising refining process, corrosion tests were carried out with raw mineral gasoline and its mixture with used cooking oil and animal waste lard in relative quantities of 10% (g/g. Co-processing was simulated by batch-reactor laboratory experiments. Experiments were performed at temperatures between 200 and 300ºC and a pressure in the gas phase of 90 bar containing 2% (m3/m3 hydrogen sulphide. The time span of individual tests were varied between 1 and 21 days so that we can conclude about changes in the reaction rates against time exposure of and extrapolate for longer periods of exposure. Initial and integral corrosion rates were defined by a weight loss method on standard size of coupons of all sorts of steel alloys. Corrosion rates of carbon steels indicated a linear increase with temperature and little variation with composition of the biomass fuel sources. Apparent activation energies over the first 24-hour period remained moderate, varying between 35.5 and 50.3 kJ mol−1. Scales developed on carbon steels at higher

Catalytic Metal Free Production of Large Cage Structure Carbon Particles: A Candidate for Hydrogen Storage

Science.gov (United States)

Kimura, Yuki; Nuth, Joseph A., III; Ferguson, Frank T.

2005-01-01

We will demonstrate that carbon particles consisting of large cages can be produced without catalytic metal. The carbon particles were produced in CO gas as well as by introduction of 5% methane gas into the CO gas. The gas-produced carbon particles were able to absorb approximately 16.2 wt% of hydrogen. This value is 2.5 times higher than the 6.5 wt% goal for the vehicular hydrogen storage proposed by the Department of Energy in the USA. Therefore, we believe that this carbon particle is an excellent candidate for hydrogen storage for fuel cells.

Renewable energy

DEFF Research Database (Denmark)

Olsen, Birgitte Egelund

2016-01-01

Renewable energy projects are increasingly confronted by local opposition, which delays and sometimes even prevents their implementation. This reflects the frequent gap between support for the general idea of renewables as a strategy for reducing carbon emissions, and acceptance of renewable energy...

Effects of hydrogen on carbon steels at the Multi-Function Waste Tank Facility

International Nuclear Information System (INIS)

Carlos, W.C.

1995-01-01

Concern has been expressed that hydrogen produced by corrosion, radiolysis, and decomposition of the waste could cause embrittlement of the carbon steel waste tanks at Hanford. The concern centers on the supposition that the hydrogen evolved in many of the existing tanks might penetrate the steel wall of the tank and cause embrittlement that might lead to catastrophic failure. This document reviews literature on the effects of hydrogen on the carbon steel proposed for use in the Multi-Function Waste Tank Facility for the time periods before and during construction as well as for the operational life of the tanks. The document draws several conclusions about these effects. Molecular hydrogen is not a concern because it is not capable of entering the steel tank wall. Nascent hydrogen produced by corrosion reactions will not embrittle the steel because the mild steel used in tank construction is not hard enough to be susceptible to hydrogen stress cracking and the corrosion product hydrogen is not produced at a rate sufficient to cause either loss in tensile ductility or blistering. If the steel intended for use in the tanks is produced to current technology, fabricated in accordance with good construction practice, postweld heat treated, and operated within the operating limits defined, hydrogen will not adversely affect the carbon steel tanks during their 50-year design life. 26 refs

Direct measurements of adsorption heats of hydrogen on nano-porous carbons

International Nuclear Information System (INIS)

Akihiko, Matsumoto; Kazumasa, Yamamoto; Tomoyuki, Miyata

2005-01-01

Since a exciting report of hydrogen storage in single-walled carbon nano-tubes by Dillon and his colleagues [1], nano-porous carbon materials, such as carbon nano-tubes, carbon nano-horns and micro-porous activated carbon, have attracted considerable attention as hydrogen storage materials. Adsorption plays a predominating role in the hydrogen storage process on solid surfaces. The adsorption is a spontaneous process, which is caused by interaction between gas molecules and surface, hence, it is always exothermic process and observed as adsorption heats. For this reason, direct measurement of the adsorption heats by adsorption microcalorimetry would provide quantitative information on the strength of adsorption interaction and the adsorption mechanism. However, the adsorption amounts of hydrogen on carbon materials are far less than those of condensable vapors near room temperature due to low critical temperature of hydrogen (33.2 K), therefore, the adsorption heats can not be determined accurately at conventional measurement conditions near room temperature and the atmospheric pressure. This contribution reports the calorimetric characterization of hydrogen adsorption on nano-porous carbon materials at low temperature and high-pressure conditions. The high-pressure adsorption apparatus consists of a volumetric adsorption line connected to a twin-conduction type microcalorimeter. Activated carbon fibers (ACF, Ad'all Co.) of different micropore sizes (Table 1) were used as model adsorbents. Each ACF has slit-shaped micropores of uniform size [2]. The adsorption isotherms and differential heats of adsorption at high-pressure region from 0 to 10 MPa were simultaneously measured at isothermal condition from 203 to 298 K. The adsorption isotherms on ACF were of Henry type regardless of adsorption temperature and pore width; the uptakes increased linearly with equilibrium pressure. The adsorption isotherm at lower sorption temperature tended to show higher sorptivity

Cloning single wall carbon nanotubes for hydrogen storage

Energy Technology Data Exchange (ETDEWEB)

Tour, James M [Rice Univ., Houston, TX (United States); Kittrell, Carter [Rice Univ., Houston, TX (United States)

2012-08-30

The purpose of this research is to development the technology required for producing 3-D nano-engineered frameworks for hydrogen storage based on sp² carbon media, which will have high gravimetric and especially high volumetric uptake of hydrogen, and in an aligned fibrous array that will take advantage of the exceptionally high thermal conductivity of sp² carbon materials to speed up the fueling process while minimizing or eliminating the need for internal cooling systems. A limitation for nearly all storage media using physisorption of the hydrogen molecule is the large amount of surface area (SA) occupied by each H₂ molecule due to its large zero-point vibrational energy. This creates a conundrum that in order to maximize SA, the physisorption media is made more tenuous and the density is decreased, usually well below 1 kg/L, so that there comes a tradeoff between volumetric and gravimetric uptake. Our major goal was to develop a new type of media with high density H₂ uptake, which favors volumetric storage and which, in turn, has the capability to meet the ultimate DoE H₂ goals.

Preparation, microstructure and hydrogen sorption properties of nanoporous carbon aerogels under ambient drying

International Nuclear Information System (INIS)

Tian, H Y; Buckley, C E; Mule, S; Paskevicius, M; Dhal, B B

2008-01-01

Organic aerogels are prepared by the sol-gel method from polymerization of resorcinol with furfural. These aerogels are further carbonized in nitrogen in order to obtain their corresponding carbon aerogels (CA); a sample which was carbonized at 900 deg. C was also activated in a carbon dioxide atmosphere at 900 deg. C. The chemical reaction mechanism and optimum synthesis conditions are investigated by means of Fourier transform infrared spectroscopy and thermoanalyses (thermogravimetric/differential thermal analyses) with a focus on the sol-gel process. The carbon aerogels were investigated with respect to their microstructures, using small angle x-ray scattering (SAXS), transmission electron microscopy (TEM) and nitrogen adsorption measurements at 77 K. SAXS studies showed that micropores with a radius of gyration of 2 g -1 displayed a reasonably high hydrogen uptake at 77 K with a maximum hydrogen sorption of 3.6 wt% at 2.5 MPa. These results suggest that CA are promising candidate hydrogen storage materials.

Nitrogen-Rich Polyacrylonitrile-Based Graphitic Carbons for Hydrogen Peroxide Sensing

Directory of Open Access Journals (Sweden)

Brandon Pollack

2017-10-01

Full Text Available Catalytic substrate, which is devoid of expensive noble metals and enzymes for hydrogen peroxide (H2O2, reduction reactions can be obtained via nitrogen doping of graphite. Here, we report a facile fabrication method for obtaining such nitrogen doped graphitized carbon using polyacrylonitrile (PAN mats and its use in H2O2 sensing. A high degree of graphitization was obtained with a mechanical treatment of the PAN fibers embedded with carbon nanotubes (CNT prior to the pyrolysis step. The electrochemical testing showed a limit of detection (LOD 0.609 µM and sensitivity of 2.54 µA cm−2 mM−1. The promising sensing performance of the developed carbon electrodes can be attributed to the presence of high content of pyridinic and graphitic nitrogens in the pyrolytic carbons, as confirmed by X-ray photoelectron spectroscopy. The reported results suggest that, despite their simple fabrication, the hydrogen peroxide sensors developed from pyrolytic carbon nanofibers are comparable with their sophisticated nitrogen-doped graphene counterparts.

Hydrogen transmission/storage with a metal hydride/organic slurry

Energy Technology Data Exchange (ETDEWEB)

Breault, R.W.; Rolfe, J.; McClaine, A. [Thermo Power Corp., Waltham, MA (United States)

1998-08-01

Thermo Power Corporation has developed a new approach for the production, transmission, and storage of hydrogen. In this approach, a chemical hydride slurry is used as the hydrogen carrier and storage media. The slurry protects the hydride from unanticipated contact with moisture in the air and makes the hydride pumpable. At the point of storage and use, a chemical hydride/water reaction is used to produce high-purity hydrogen. An essential feature of this approach is the recovery and recycle of the spent hydride at centralized processing plants, resulting in an overall low cost for hydrogen. This approach has two clear benefits: it greatly improves energy transmission and storage characteristics of hydrogen as a fuel, and it produces the hydrogen carrier efficiently and economically from a low cost carbon source. The preliminary economic analysis of the process indicates that hydrogen can be produced for $3.85 per million Btu based on a carbon cost of $1.42 per million Btu and a plant sized to serve a million cars per day. This compares to current costs of approximately $9.00 per million Btu to produce hydrogen from $3.00 per million Btu natural gas, and $25 per million Btu to produce hydrogen by electrolysis from $0.05 per Kwh electricity. The present standard for production of hydrogen from renewable energy is photovoltaic-electrolysis at $100 to $150 per million Btu.

Advanced nanostructured materials as media for hydrogen storage

International Nuclear Information System (INIS)

David, E.; Niculescu, V.; Armeanu, A.; Sandru, C.; Constantinescu, M.; Sisu, C.

2005-01-01

Full text: In a future sustainable energy system based on renewable energy, environmentally harmless energy carriers like hydrogen, will be of crucial importance. One of the major impediments for the transition to a hydrogen based energy system is the lack of satisfactory hydrogen storage alternatives. Hydrogen storage in nanostructured materials has been proposed as a solution for adequate hydrogen storage for a number of applications, in particular for transportation. This paper is a preliminary study with the focus on possibilities for hydrogen storage in zeolites, alumina and nanostructured carbon materials. The adsorption properties of these materials were evaluated in correlation with their internal structure. From N 2 physisorption data the BET surface area (S BET ) , total pore volume (PV), micropore volume (MPV) and total surface area (S t ) were derived. H 2 physisorption measurements were performed at 77 K and a pressure value of 1 bar. From these data the adsorption capacities of sorbent materials were determined. Apparently the microporous adsorbents, e.g activated carbons, display appreciable sorption capacities. Based on their micropore volume, carbon-based sorbents have the largest adsorption capacity for H 2 , over 230 cm 3 (STP)/g, at the previous conditions. By increasing the micropore volume (∼ 1 cm 3 /g) of sorbents and optimizing the adsorption conditions it is expected to obtain an adsorption capacity of ∼ 560 cm 3 (STP)/g, close to targets set for mobile applications. (authors)

2012 Renewable Energy Data Book (Book)

Energy Technology Data Exchange (ETDEWEB)

Gelman, R.

2013-10-01

This Renewable Energy Data Book for 2012 provides facts and figures in a graphical format on energy in general, renewable electricity in the United States, global renewable energy development, wind power, solar power, geothermal power, biopower, hydropower, advanced water power, hydrogen, renewable fuels, and clean energy investment.

The role of hydrogen as a future solution to energetic and environmental problems for residential buildings

Science.gov (United States)

Badea, G.; Felseghi, R. A.; Aşchilean, I.; Rǎboacǎ, S. M.; Şoimoşan, T.

2017-12-01

The concept of sustainable development aims to meet the needs of the present without compromising the needs of future generations. In achieving the desideratum "low-carbon energy system", in the domain of energy production, the use of innovative low-carbon technologies providing maximum efficiency and minimum pollution is required. Such technology is the fuel cell; as these will be developed, it will become a reality to obtain the energy based on hydrogen. Thus, hydrogen produced by electrolysis of water using different forms of renewable resources becomes a secure and sustainable energy alternative. In this context, in the present paper, a comparative study of two different hybrid power generation systems for residential building placed in Cluj-Napoca was made. In these energy systems have been integrated renewable energies (photovoltaic panels and wind turbine), backup and storage system based on hydrogen (fuel cell, electrolyser and hydrogen storage tank), and, respectively, backup and storage system based on traditional technologies (diesel generator and battery). The software iHOGA was used to simulate the operating performance of the two hybrid systems. The aim of this study was to compare energy, environmental and economic performances of these two systems and to define possible future scenarios of competitiveness between traditional and new innovative technologies. After analyzing and comparing the results of simulations, it can be concluded that the fuel cells technology along with hydrogen, integrated in a hybrid system, may be the key to energy production systems with high energy efficiency, making possible an increased capitalization of renewable energy which have a low environmental impact.

Hydrogen spillover in Pt-single-walled carbon nanotube composites: formation of stable C-H bonds.

Science.gov (United States)

Bhowmick, Ranadeep; Rajasekaran, Srivats; Friebel, Daniel; Beasley, Cara; Jiao, Liying; Ogasawara, Hirohito; Dai, Hongjie; Clemens, Bruce; Nilsson, Anders

2011-04-13

Using in situ electrical conductivity and ex situ X-ray photoelectron spectroscopy (XPS) measurements, we have examined how the hydrogen uptake of single-walled carbon nanotubes (SWNTs) is influenced by the addition of Pt nanoparticles. The conductivity of platinum-sputtered single-walled carbon nanotubes (Pt-SWNTs) during molecular hydrogen exposure decreased more rapidly than that of the corresponding pure SWNTs, which supports a hydrogenation mechanism facilitated by "spillover" of dissociated hydrogen from the Pt nanoparticles. C 1s XPS spectra indicate that the Pt-SWNTs store hydrogen by means of chemisorption, that is, covalent C-H bond formation: molecular hydrogen charging at elevated pressure (8.27 bar) and room temperature yielded Pt-SWNTs with up to 16 ± 1.5 at. % sp(3)-hybridized carbon atoms, which corresponds to a hydrogen-storage capacity of 1.2 wt % (excluding the weight of Pt nanoparticles). Pt-SWNTs prepared by the Langmuir-Blodgett (LB) technique exhibited the highest Pt/SWNT ratio and also the best hydrogen uptake. © 2011 American Chemical Society

Hydrogen storage studies on palladium-doped carbon materials (AC, CB, CNMs) @ metal-organic framework-5.

Science.gov (United States)

Viditha, V; Srilatha, K; Himabindu, V

2016-05-01

Metal organic frameworks (MOFs) are a rapidly growing class of porous materials and are considered as best adsorbents for their high surface area and extraordinary porosity. The MOFs are synthesized by using various chemicals like triethylamine, terepthalic acid, zinc acetate dihydrate, chloroform, and dimethylformamide (DMF). Synthesized MOFs are intercalated with palladium/activated carbon, carbon black, and carbon nanomaterials by chemical reduction method for the purpose of enhancing the hydrogen adsorption capacities. We have observed that the palladium doped activated carbon on MOF-5 showed high hydrogen storage capacity. This may be due to the affinity of the palladium toward hydrogen molecule. The samples are characterized by X-ray diffraction, scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) surface area analysis. We have observed a clear decrease in the BET surface area and pore volume. The obtained results show a better performance for the synthesized sample. To our best knowledge, no one has reported the work on palladium-doped carbon materials (activated carbon, carbon black, carbon nanomaterials) impregnated to the metal-organic framework-5. We have attempted to synthesize carbon nanomaterials using indigenously fabricated chemical vapor deposition (CVD) unit as a support. We have observed an increase in the hydrogen storage capacities.

Continuously renewed wall for a thermonuclear reactor

International Nuclear Information System (INIS)

Livshits, A.I.; Pustovojt, YU.M.; Samartsev, A.A.; Gosudarstvennyj Komitet po Ispol'zovaniyu Atomnoj Ehnergii SSSR, Moscow. Inst. Atomnoj Ehnergii)

1982-01-01

The possibility of creating a continuously renewed first wall of a thermonuclear reactor is experimentally investigated. The following variants of the wall are considered: the wall is double, its part turned to plasma is made of comparatively thin material. The external part separated from it by a small gap appears to be protected from interaction with plasma and performs structural functions. The gap contains the mixture of light helium and hydrogen and carbon-containing gas. The light gas transfers heat from internal part of the wall to the external part. Carbon-containing gas provides continuous renewal of carbon coating of the operating surface. The experiment is performed with palladium membrane 20 μm thick. Carbon is introduced into the membrane by benzol pyrolysis on one of the surfaces at the membrane temperature of 900 K. Carbon removal from the operating side of the wall due to its spraying by fast particles is modelled by chemical itching with oxygen given to the operating membrane wall. Observation of the carbon release on the operating surface is performed mass-spectrometrically according to the observation over O 2 transformation into CO and CO 2 . It is shown that in cases of benzol pressure of 5x10 -7 torr, carbon current on the opposite surface is not less than 3x10 12 atoms/sm 2 s and corresponds to the expected wall spraying rate in CF thermonuclear reactors. It is also shown that under definite conditions the formation and maintaining of a through protective carbon coating in the form of a monolayer or volumetric phase is possible

Hydrogen from biomass: state of the art and research challenges

Energy Technology Data Exchange (ETDEWEB)

Milne, Thomas A; Elam, Carolyn C; Evans, Robert J

2002-02-01

The report was prepared for the International Energy Agency (IEA) Agreement on the Production and Utilization of Hydrogen, Task 16, Hydrogen from Carbon-Containing Materials. Hydrogen's share in the energy market is increasing with the implementation of fuel cell systems and the growing demand for zero-emission fuels. Hydrogen production will need to keep pace with this growing market. In the near term, increased production will likely be met by conventional technologies, such as natural gas reforming. In these processes, the carbon is converted to CO2 and released to the atmosphere. However, with the growing concern about global climate change, alternatives to the atmospheric release of CO2 are being investigated. Sequestration of the CO2 is an option that could provide a viable near-term solution. Reducing the demand on fossil resources remains a significant concern for many nations. Renewable-based processes like solar- or wind-driven electrolysis and photobiological water splitting hold great promise for clean hydrogen production; however, advances must still be made before these technologies can be economically competitive. For the near-and mid-term, generating hydrogen from biomass may be the more practical and viable, renewable and potentially carbon-neutral (or even carbon-negative in conjunction with sequestration) option. Recently, the IEA Hydrogen Agreement launched a new task to bring together international experts to investigate some of these near- and mid-term options for producing hydrogen with reduced environmental impacts. This review of the state of the art of hydrogen production from biomass was prepared to facilitate in the planning of work that should be done to achieve the goal of near-term hydrogen energy systems. The relevant technologies that convert biomass to hydrogen, with emphasis on thermochemical routes are described. In evaluating the viability of the conversion routes, each must be put in the context of the availability of

Ab initio calculations on hydrogen storage in porous carbons

International Nuclear Information System (INIS)

Maresca, O.; Marinelli, F.; Pellenq, R.J.M.; Duclaux, L.; Azais, Ph.; Conard, J.

2005-01-01

We have investigated through ab initio computations the possible ways to achieve efficient hydrogen storage on carbons. Firstly, we have considered how the curvature of a carbon surface could affect the chemisorption of atomic H 0 Secondly, we show that electron donor elements such as Li and K, used as dopants for the carbon substrate, strongly enhance the physi-sorption energy of H 2 , allowing in principle its storage in this type of material at room temperature under mild conditions of pressure. (authors)

Catalytic hydrogenation of carbon monoxide

International Nuclear Information System (INIS)

Wayland, B.B.

1993-12-01

Focus of this project is on developing new approaches for hydrogenation of carbon monoxide to produce organic oxygenates at mild conditions. The strategies to accomplish CO reduction are based on favorable thermodynamics manifested by rhodium macrocycles for producing a series of intermediates implicated in the catalytic hydrogenation of CO. Metalloformyl complexes from reactions of H 2 and CO, and CO reductive coupling to form metallo α-diketone species provide alternate routes to organic oxygenates that utilize these species as intermediates. Thermodynamic and kinetic-mechanistic studies are used in guiding the design of new metallospecies to improve the thermodynamic and kinetic factors for individual steps in the overall process. Electronic and steric effects associated with the ligand arrays along with the influences of the reaction medium provide the chemical tools for tuning these factors. Non-macrocyclic ligand complexes that emulate the favorable thermodynamic features associated with rhodium macrocycles, but that also manifest improved reaction kinetics are promising candidates for future development

Solar-Driven Hydrogen Peroxide Production Using Polymer-Supported Carbon Dots as Heterogeneous Catalyst

Science.gov (United States)

Gogoi, Satyabrat; Karak, Niranjan

2017-10-01

Safe, sustainable, and green production of hydrogen peroxide is an exciting proposition due to the role of hydrogen peroxide as a green oxidant and energy carrier for fuel cells. The current work reports the development of carbon dot-impregnated waterborne hyperbranched polyurethane as a heterogeneous photo-catalyst for solar-driven production of hydrogen peroxide. The results reveal that the carbon dots possess a suitable band-gap of 2.98 eV, which facilitates effective splitting of both water and ethanol under solar irradiation. Inclusion of the carbon dots within the eco-friendly polymeric material ensures their catalytic activity and also provides a facile route for easy catalyst separation, especially from a solubilizing medium. The overall process was performed in accordance with the principles of green chemistry using bio-based precursors and aqueous medium. This work highlights the potential of carbon dots as an effective photo-catalyst.

Modification of rubber surface with hydrogenated diamond-like carbon thin films

NARCIS (Netherlands)

Pei, Y. T.; Bui, X. L.; De Hosson, J. Th. M.; Laudon, M; Romanowicz, B

2009-01-01

Thin films of hydrogenated diamond-like carbon (DLC) have been deposited on hydrogenated nitrile butadiene rubber (HNBR) for reduction of friction and enhancement of wear resistance of dynamic rubber seals, by sputtering graphite targets in C(2)H(2)/Ar plasma. The wax removal and pre-deposition

Hydrogen storage in single-walled carbon nanotubes: methods and results

International Nuclear Information System (INIS)

Poirier, E.; Chahine, R.; Tessier, A.; Cossement, D.; Lafi, L.; Bose, T.K.

2004-01-01

We present high sensitivity gravimetric and volumetric hydrogen sorption measurement systems adapted for in situ conditioning under high temperature and high vacuum. These systems, which allow for precise measurements on small samples and thorough degassing, are used for sorption measurements on carbon nanostructures. We developed one volumetric system for the pressure range 0-1 bar, and two gravimetric systems for 0-1 bar and 0-100 bars. The use of both gravimetric and volumetric methods allows for the cross-checking of the results. The accuracy of the systems has been determined from hydrogen absorption measurements on palladium. The accuracies of the 0-1 bar volumetric and gravimetric systems are about 10 μg and 20 μg respectively. The accuracy of the 0-100 bars gravimetric system is about 20 μg. Hydrogen sorption measurements on single-walled carbon nanotubes (SWNTs) and metal-incorporated- SWNTs are presented. (author)

Future role of hydrogen in FRG

International Nuclear Information System (INIS)

Bradke, H.

1992-01-01

Relative to the Federal Republic of Germany energy-economy framework, this paper prepares supply and demand assessments for a set of energy source diversification strategy alternatives involving the substantial use of hydrogen fuels, with the aim of reducing the strain on the the earth's limited supplies of fossil fuels and limiting carbon dioxide emissions into the atmosphere. These assessments include forecasts of population dynamics, GNP, and sectoral energy consumption, production, imports and prices for fossil fuels and renewable energy sources. The comparative evaluation of the diversification scenarios includes sensitivity analyses to establish the optimum mix of economy-energy planning criteria that would allow for the successful evolution of a hydrogen based economy in the FRG by the year 2040

Cationic mononuclear ruthenium carboxylates as catalyst prototypes for self-induced hydrogenation of carboxylic acids.

Science.gov (United States)

Naruto, Masayuki; Saito, Susumu

2015-08-28

Carboxylic acids are ubiquitous in bio-renewable and petrochemical sources of carbon. Hydrogenation of carboxylic acids to yield alcohols produces water as the only byproduct, and thus represents a possible next generation, sustainable method for the production of these alternative energy carriers/platform chemicals on a large scale. Reported herein are molecular insights into cationic mononuclear ruthenium carboxylates ([Ru(OCOR)](+)) as prototypical catalysts for the hydrogenation of carboxylic acids. The substrate-derived coordinated carboxylate was found to function initially as a proton acceptor for the heterolytic cleavage of dihydrogen, and subsequently also as an acceptor for the hydride from [Ru-H](+), which was generated in the first step (self-induced catalysis). The hydrogenation proceeded selectively and at high levels of functional group tolerance, a feature that is challenging to achieve with existing heterogeneous/homogeneous catalyst systems. These fundamental insights are expected to significantly benefit the future development of metal carboxylate-catalysed hydrogenation processes of bio-renewable resources.

Technoeconomical analysis of the co-production of hydrogen energy and carbon materials

Science.gov (United States)

Guerra, Zuimdie

HECAM (Hydrogen Energy and Carbon Materials) is a new energy production strategy. The main paradigm of HECAM is that energy extracted from the carbon in hydrocarbon fuels is not worth the production of carbon dioxide. The hydrocarbon fuel is heated in an oxygen free environment and it is chemically decomposed by the heat into gases (mostly hydrogen and methane), small quantities of liquid (light oil and tar), and a solid residue containing carbon and ash (char or coke). More quantities of hydrocarbons will need to be used, but less carbon dioxide will be produced. HECAM is going to compete with steam methane reforming (SMR) to produce hydrogen. HECAM with thermocatalytic decomposition of methane and efficient sensible heat recovery has a production cost per gigajoule of hydrogen about 9% higher than SMR, but will produce about half the carbon dioxide emissions that SMR produces. If HECAM with efficient sensible heat recovery is used to produce electricity in a power plant, it will have a comparable electricity production cost and carbon dioxide emissions to a natural gas combined cycle (NGCC) power plant. The byproduct coke is not a waste residue, but a valuable co-product. Uses for the byproduct coke material may be carbon sequestration, mine land restoration, additive to enhance agricultural soils, low sulfur and mercury content heating fuel for power plants, new construction materials, or carbon-base industrial materials. This study investigated the use of byproduct coke for new construction materials. HECAM concrete substitute (HCS) materials will have a comparable cost with concrete when the cost of the raw materials is $65 per metric ton of HCS produced. HECAM brick substitute (HBS) materials will have 20% higher cost per brick than clay bricks. If the HECAM byproduct coke can be formed into bricks as a product of the HECAM process, the manufacture of HBS bricks will be cheaper and may be cost competitive with clay bricks. The results of this analysis are

Are carbon nanostructures an efficient hydrogen storage medium?

NARCIS (Netherlands)

Hirscher, M.; Becher, M.; Haluska, M.; Zeppelin, von F.; Chen, X.; Dettlaff-Weglikowska, U.; Roth, S.

2003-01-01

Literature data on the storage capacities of hydrogen in carbon nanostructures show a scatter over several orders of magnitude which cannot be solely explained by the limited quantity or purity of these novel nanoscale materials. With this in mind, this article revisits important experiments.

Analytic Methods for Benchmarking Hydrogen and Fuel Cell Technologies; NREL (National Renewable Energy Laboratory)

Energy Technology Data Exchange (ETDEWEB)

Melaina, Marc; Saur, Genevieve; Ramsden, Todd; Eichman, Joshua

2015-05-28

This presentation summarizes NREL's hydrogen and fuel cell analysis work in three areas: resource potential, greenhouse gas emissions and cost of delivered energy, and influence of auxiliary revenue streams. NREL's hydrogen and fuel cell analysis projects focus on low-­carbon and economic transportation and stationary fuel cell applications. Analysis tools developed by the lab provide insight into the degree to which bridging markets can strengthen the business case for fuel cell applications.

Carbon Lock-Out: Advancing Renewable Energy Policy in Europe

Directory of Open Access Journals (Sweden)

Robert Pietzcker

2012-02-01

Full Text Available As part of its climate strategy, the EU aims at increasing the share of electricity from renewable energy sources (RES-E in overall electricity generation. Attaining this target poses a considerable challenge as the electricity sector is “locked” into a carbon-intensive system, which hampers the adoption of RES-E technologies. Electricity generation, transmission and distribution grids as well as storage and demand response are subject to important path dependences, which put existing, non-renewable energy sources at an advantage. This paper examines how an EU framework for RES-E support policies should be designed to facilitate a carbon lock-out. For this purpose, we specify the major technological, economic and institutional barriers to RES-E. For each of the barriers, a policy review is carried out which assesses the performance of existing policy instruments and identifies needs for reform. The review reveals several shortcomings: while policies targeting generation are widely in place, measures to address barriers associated with electricity grids, storage and demand are still in their infancy and have to be extended. Moreover, the implementation of policies has been fragmented across EU Member States. In this respect, national policies should be embedded into an integrated EU-wide planning of the RES-E system with overarching energy scenarios and partially harmonized policy rules.

The hydrogen and oxygen content of self-supporting carbon foils prepared by dc glow discharge in ethylene

International Nuclear Information System (INIS)

Tait, N.R.S.; Tolfree, D.W.L.; John, P.; Odeh, I.M.; Thomas, M.J.K.; Tricker, M.J.; Wilson, J.J.B.; England, J.B.A.; Newton, D.

1980-01-01

The hydrogen and oxygen content of self-supporting carbon films produced by dc glow discharge have been determined using a precise method involving the elastic scattering of 25 MeV α-particles. The number of carbon-hydrogen bonds has been determined for similar samples using infrared spectroscopy. The results are compared with those for samples made by the carbon arc process. Assuming that the glow discharge carbon contains graphitic regions surrounded by amorphous tetrahedrally bonded material to which hydrogen can attach, a simple estimate is made of the relative numbers of carbon atoms in the two forms. (orig.)

Influence of surface treatments on micropore structure and hydrogen adsorption behavior of nanoporous carbons.

Science.gov (United States)

Kim, Byung-Joo; Park, Soo-Jin

2007-07-15

The scope of this work was to control the pore sizes of porous carbons by various surface treatments and to investigate the relation between pore structures and hydrogen adsorption capacity. The effects of various surface treatments (i.e., gas-phase ozone, anodic oxidation, fluorination, and oxygen plasma) on the micropore structures of porous carbons were investigated by N(2)/77 K isothermal adsorption. The hydrogen adsorption capacity was measured by H(2) isothermal adsorption at 77 K. In the result, the specific surface area and micropore volume of all of the treated samples were slightly decreased due to the micropore filling or pore collapsing behaviors. It was also found that in F(2)-treated carbons the center of the pore size distribution was shifted to left side, meaning that the average size of the micropores decreased. The F(2)- and plasma-treated samples showed higher hydrogen storage capacities than did the other samples, the F(2)-treated one being the best, indicating that the micropore size of the porous carbons played a key role in the hydrogen adsorption at 77 K.

Carbon dioxide emission in hydrogen production technology from coke oven gas with life cycle approach

Directory of Open Access Journals (Sweden)

Burmistrz Piotr

2016-01-01

Full Text Available The analysis of Carbon Footprint (CF for technology of hydrogen production from cleaned coke oven gas was performed. On the basis of real data and simulation calculations of the production process of hydrogen from coke gas, emission indicators of carbon dioxide (CF were calculated. These indicators are associated with net production of electricity and thermal energy and direct emission of carbon dioxide throughout a whole product life cycle. Product life cycle includes: coal extraction and its transportation to a coking plant, the process of coking coal, purification and reforming of coke oven gas, carbon capture and storage. The values were related to 1 Mg of coking blend and to 1 Mg of the hydrogen produced. The calculation is based on the configuration of hydrogen production from coke oven gas for coking technology available on a commercial scale that uses a technology of coke dry quenching (CDQ. The calculations were made using ChemCAD v.6.0.2 simulator for a steady state of technological process. The analysis of carbon footprint was conducted in accordance with the Life Cycle Assessment (LCA.

Detection of carbon dioxide in the gases evolved during the hot extraction determination of hydrogen in uranium ingots

International Nuclear Information System (INIS)

Jursik, M.L.; Pope, J.D.

1977-08-01

The hot extraction method was used at the National Lead Company of Ohio to determine hydrogen in uranium metal at the 2 ppM level. The volume of gas evolved from the heated sample was assumed to be hydrogen. When a liquid nitrogen trap was placed into the system the hydrogen values were reduced 5 to 10%. The gas retained by the nitrogen trap was identified by mass spectrometry as predominantly carbon dioxide. Low hydrogen values were observed only when the nitrogen trap was used in the analysis of high-carbon (300 to 600 ppM) uranium from NLO production ingots. However, hydrogen values for low-carbon (30 to 50 ppM) uranium were unaffected by the nitrogen trap. The formation of carbon dioxide appears to be associated with the carbon content of the uranium metal. Comparisons of hydrogen values obtained with the hot extraction method and with an inert fusion--thermal conductivity method are also presented. 3 tables, 4 figures

[Hydrogen systems analysis, education, and outreach

Energy Technology Data Exchange (ETDEWEB)

None

1998-01-01

This paper illustrates a search of web sites on the keyword, Hydrogen, and a second search combining keywords, Hydrogen and Renewable Energy. Names, addresses, and E-mail addresses or web site URLs are given for a number of companies and government or commercial organizations dealing with hydrogen fuel cells. Finally, brief summaries are given on hydrogen research projects at the National Renewable Energy Laboratory.

Study on the production of alternative fuels by carbon dioxide hydrogenation

Energy Technology Data Exchange (ETDEWEB)

Sim, Kyu Sung; Han, Sang Do; Kim, Jong Won; Kim, Youn Soon; Seo, Ji Mi [Korea Inst. of Energy Research, Taejon (Korea, Republic of)

1995-12-01

The technologies of the fuel production from carbon dioxide by catalytic hydrogenation were surveyed. For the catalytic hydrogenation we made the lab-scale reaction apparatus and carried out some experiments with various catalysts like CuO/ZnO/Al{sub 2}O{sub 3}, Raney nickel and other commercial catalysts. In this year, the third year of the project, the experiments to find optimum catalysts and obtain the good conditions of carbon dioxide were performed followed by second year. And also the processes of the methanol synthesis was investigated simultaneously. (author). 58 refs., 58 figs., 28 tabs.

Challenges for renewable hydrogen production from biomass

International Nuclear Information System (INIS)

Levin, David B.; Chahine, Richard

2010-01-01

The increasing demand for H 2 for heavy oil upgrading, desulfurization and upgrading of conventional petroleum, and for production of ammonium, in addition to the projected demand for H 2 as a transportation fuel and portable power, will require H 2 production on a massive scale. Increased production of H 2 by current technologies will consume greater amounts of conventional hydrocarbons (primarily natural gas), which in turn will generate greater greenhouse gas emissions. Production of H 2 from renewable sources derived from agricultural or other waste streams offers the possibility to contribute to the production capacity with lower or no net greenhouse gas emissions (without carbon sequestration technologies), increasing the flexibility and improving the economics of distributed and semi-centralized reforming. Electrolysis, thermocatalytic, and biological production can be easily adapted to on-site decentralized production of H 2 , circumventing the need to establish a large and costly distribution infrastructure. Each of these H 2 production technologies, however, faces technical challenges, including conversion efficiencies, feedstock type, and the need to safely integrate H 2 production systems with H 2 purification and storage technologies. (author)

Coulometric determination of dissolved hydrogen with a multielectrolytic modified carbon felt electrode-based sensor.

Science.gov (United States)

Matsuura, Hiroaki; Yamawaki, Yosuke; Sasaki, Kosuke; Uchiyama, Shunichi

2013-06-01

A multielectrolytic modified carbon electrode (MEMCE) was fabricated by the electrolytic-oxidation/reduction processes. First, the functional groups containing nitrogen atoms such as amino group were introduced by the electrode oxidation of carbon felt electrode in an ammonium carbamate aqueous solution, and next, this electrode was electroreduced in sulfuric acid. The redox waves between hydrogen ion and hydrogen molecule at highly positive potential range appeared in the cyclic voltammogram obtained by MEMCE. A coulometric cell using MEMCE with a catalytic activity of electrooxidation of hydrogen molecule was constructed and was used for the measurement of dissolved hydrogen. The typical current vs. time curve was obtained by the repetitive measurement of the dissolved hydrogen. These curves indicated that the measurement of dissolved hydrogen was finished completely in a very short time (ca. 10 sec). A linear relationship was obtained between the electrical charge needed for the electrooxidation process of hydrogen molecule and dissolved hydrogen concentration. This indicates that the developed coulometric method can be used for the determination of the dissolved hydrogen concentration.

Why hydrogen; Pourquoi l'hydrogene?

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-02-01

The energy consumption increase and the associated environmental risks, led to develop new energy sources. The authors present the potentialities of the hydrogen in this context of energy supply safety. They detail the today market and the perspectives, the energy sources for the hydrogen production (fossils, nuclear and renewable), the hydrogen transport, storage, distribution and conversion, the application domains, the associated risks. (A.L.B.)

Multiscale Mathematics for Biomass Conversion to Renewable Hydrogen

Energy Technology Data Exchange (ETDEWEB)

Plechac, Petr [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Mathematics; Univ. of Delaware, Newark, DE (United States). Dept. of Mathematics; Vlachos, Dionisios [Univ. of Delaware, Newark, DE (United States). Dept. of Chemical and Biomolecular Engineering; Katsoulakis, Markos [Univ. of Massachusetts, Amherst, MA (United States). Dept. of Mathematics

2013-09-05

The overall objective of this project is to develop multiscale models for understanding and eventually designing complex processes for renewables. To the best of our knowledge, our work is the first attempt at modeling complex reacting systems, whose performance relies on underlying multiscale mathematics. Our specific application lies at the heart of biofuels initiatives of DOE and entails modeling of catalytic systems, to enable economic, environmentally benign, and efficient conversion of biomass into either hydrogen or valuable chemicals. Specific goals include: (i) Development of rigorous spatio-temporal coarse-grained kinetic Monte Carlo (KMC) mathematics and simulation for microscopic processes encountered in biomass transformation. (ii) Development of hybrid multiscale simulation that links stochastic simulation to a deterministic partial differential equation (PDE) model for an entire reactor. (iii) Development of hybrid multiscale simulation that links KMC simulation with quantum density functional theory (DFT) calculations. (iv) Development of parallelization of models of (i)-(iii) to take advantage of Petaflop computing and enable real world applications of complex, multiscale models. In this NCE period, we continued addressing these objectives and completed the proposed work. Main initiatives, key results, and activities are outlined.

Applying life-cycle assessment to low carbon fuel standards-How allocation choices influence carbon intensity for renewable transportation fuels

International Nuclear Information System (INIS)

Kaufman, Andrew S.; Meier, Paul J.; Sinistore, Julie C.; Reinemann, Douglas J.

2010-01-01

The Energy Independence and Security Act (EISA) of 2007 requires life-cycle assessment (LCA) for quantifying greenhouse gas emissions (GHGs) from expanded U.S. biofuel production. To qualify under the Renewable Fuel Standard, cellulosic ethanol and new corn ethanol must demonstrate 60% and 20% lower emissions than petroleum fuels, respectively. A combined corn-grain and corn-stover ethanol system could potentially satisfy a major portion of renewable fuel production goals. This work examines multiple LCA allocation procedures for a hypothetical system producing ethanol from both corn grain and corn stover. Allocation choice is known to strongly influence GHG emission results for corn-ethanol. Stover-derived ethanol production further complicates allocation practices because additional products result from the same corn production system. This study measures the carbon intensity of ethanol fuels against EISA limits using multiple allocation approaches. Allocation decisions are shown to be paramount. Under varying approaches, carbon intensity for corn ethanol was 36-79% that of gasoline, while carbon intensity for stover-derived ethanol was -10% to 44% that of gasoline. Producing corn-stover ethanol dramatically reduced carbon intensity for corn-grain ethanol, because substantially more ethanol is produced with only minor increases in emissions. Regulatory considerations for applying LCA are discussed.

An insight on hydrogen fuel injection techniques with SCR system for NO{sub X} reduction in a hydrogen-diesel dual fuel engine

Energy Technology Data Exchange (ETDEWEB)

Saravanan, N. [ERC Engines, Hall 11A, Tata Motors, Pimpri, Pune 411019, Maharashtra (India); Nagarajan, G. [Department of Mechanical Engineering, ICE Division, College of Engineering, Guindy, Anna University-Chennai, Chennai 600 025 (India)

2009-11-15

Internal combustion engines continue to dominate in many fields like transportation, agriculture and power generation. Among the various alternative fuels, hydrogen is a long-term renewable and less polluting fuel (Produced from renewable energy sources). In the present experimental investigation, the performance and emission characteristics were studied on a direct injection diesel engine in dual fuel mode with hydrogen inducted along with air adopting carburetion, timed port and manifold injection techniques. Results showed that in timed port injection, the specific energy consumption reduces by 15% and smoke level by 18%. The brake thermal efficiency and NO{sub X} increases by 17% and 34% respectively compared to baseline diesel. The variation in performance between port and manifold injection is not significant. The unburnt hydrocarbons and carbon monoxide emissions are lesser in port injection. The oxides of nitrogen are higher in hydrogen operation (both port and manifold injection) compared to diesel engine. In order to reduce the NO{sub X} emissions, a selective catalytic converter was used in hydrogen port fuel injection. The NO{sub X} emission reduced upto a maximum of 74% for ANR (ratio of flow rate of ammonia to the flow rate of NO) of 1.1 with a marginal reduction in efficiency. Selective catalytic reduction technique has been found to be effective in reducing the NO{sub X} emission from hydrogen fueled diesel engines. (author)

New insights on electrochemical hydrogen storage in nanoporous carbons by in situ Raman spectroscopy

OpenAIRE

Leyva García, Sarai; Morallón Núñez, Emilia; Cazorla Amorós, Diego; Béguin, François; Lozano Castelló, Dolores

2014-01-01

In situ Raman spectroscopy was exploited to analyze the interaction between carbon and hydrogen during electrochemical hydrogen storage at cathodic conditions. Two different activated carbons were used and characterized by different electrochemical techniques in two electrolytes (6 M KOH and 0.5 M Na2SO4). The in situ Raman spectra collected showed that, in addition to the D and G bands associated to the graphitic carbons, two bands appear simultaneously at about 1110 and 1500 cm−1 under cath...

Negative-ion production on carbon materials in hydrogen plasma : influence of the carbon hybridization state and the hydrogen content on H- yield

NARCIS (Netherlands)

Ahmad, A.; Pardanaud, C.; Carrère, M.; Layet, J.M.; Gicquel, A.; Kumar, P.; Eon, D.; Jaoul, C.; Engeln, R.A.H.; Cartry, G.

2014-01-01

Highly oriented polycrystalline graphite (HOPG), boron-doped diamond (BDD), nanocrystalline diamond, ultra-nanocrystalline diamond and diamond-like carbon surfaces are exposed to low-pressure hydrogen plasma in a 13.56 MHz plasma reactor. Relative yields of surface-produced H- ions due to

Molybdenum sulphides on carbon supports as electrocatalysts for hydrogen evolution in acidic industrial wastewater

International Nuclear Information System (INIS)

Kokko, M.; Bayerköhler, F.; Erben, J.; Zengerle, R.; Kurz, Ph.; Kerzenmacher, S.

2017-01-01

Highlights: • MoS_x is an efficient and durable catalyst for H_2 evolution in acidic wastewater. • MoS_x outperformed Pt as H_2-catalyst in long term in acidic wastewater. • Improved activity over time was likely due to changes in MoS_x structure. - Abstract: Microbial electrolysis cells (MECs) are an attractive future alternative technology to generate renewable hydrogen and simultaneously treat wastewaters. The thermodynamics of hydrogen evolution in MECs can be greatly improved by operating the cathode at acidic pH in combination with a neutral pH microbial anode. This can easily be achieved with acidic industrial wastewaters that have to be neutralised before discharge. For the hydrogen evolution reaction (HER) in acidic wastewater, efficient and inexpensive catalysts are required that are compatible with the often complex chemical composition of wastewaters. In this study, molybdenum sulphides (MoS_x) on different carbon supports were successfully used for hydrogen evolution in different acidic media. At first, the cathodes were screened by linear sweep voltammetry in sulphuric acid (pH 0) or phosphate buffer (pH 2.2). After this, the overpotentials for H_2 production of the best cathodes and their long term performances (⩾1 week) were determined in acidic industrial wastewater (pH 2.4) obtained from a plant mainly producing cellulose acetate. For the most promising MoS_x cathodes, the overpotentials for HER (at 3 mA cm"−"2) were only ∼40 mV higher than for a platinum electrode. Most importantly, the catalytic efficiency of the MoS_x electrodes improved in the wastewater over time (7–17 days), while Pt electrodes were found to be slowly deactivated. Thus, MoS_x emerges as an affordable, efficient and especially durable electrocatalyst for HER in real acidic wastewaters and this could be an important contribution to take energy production from wastewaters in the form of hydrogen towards practical applications.

Hydrogen storage behaviors of platinum-supported multi-walled carbon nanotubes

Energy Technology Data Exchange (ETDEWEB)

Park, Soo-Jin; Lee, Seul-Yi [Department of Chemistry, Inha University, 253 Nam-gu, Incheon 402-751 (Korea, Republic of)

2010-12-15

In this work, the hydrogen storage behaviors of multi-walled carbon nanotubes (MWNTs) loaded by crystalline platinum (Pt) particles were studied. The microstructure of the Pt/MWNTs was characterized by X-ray diffraction and transmission electron microscopy. The pore structure and total pore volumes of the Pt/MWNTs were analyzed by N{sub 2}/77 K adsorption isotherms. The hydrogen storage capacity of the Pt/MWNTs was evaluated at 298 K and 100 bar. From the experimental results, it was found that Pt particles were homogeneously distributed on the MWNT surfaces. The amount of hydrogen storage capacity increased in proportion to the Pt content, with Pt-5/MWNTs exhibiting the largest hydrogen storage capacity. The superior amount of hydrogen storage was linked to an increase in the number of active sites and the optimum-controlled micropore volume for hydrogen adsorption due to the well-dispersed Pt particles. Therefore, it can be concluded that Pt particles play an important role in hydrogen storage characteristics due to the hydrogen spillover effect. (author)

The hydrogen energy economy: its long-term role in greenhouse gas reduction

Energy Technology Data Exchange (ETDEWEB)

Geoff Dutton; Abigail Bristow; Matthew Page; Charlotte Kelly; Jim Watson; Alison Tetteh [CCLRC Rutherford Appleton Laboratory, Didcot (United Kingdom). Energy Research Unit (ERU)

2005-01-15

The potential contribution and viability of the hydrogen energy economy towards reducing UK carbon dioxide emissions in the time horizon to 2050 has been assessed using a quantitative model of the UK energy system in the context of a set of diverse socio-economic scenarios. It is argued that different sets of prevailing circumstances are likely to result in very different opportunities for hydrogen and hence very different transition pathways and ultimate penetration levels. The decision on whether to strategically encourage a transition to the hydrogen economy and the ultimate environmental benefits of such a transformation will depend on the outcome of a number of important political and social decisions. These include the acceptability of large scale carbon dioxide sequestration (hydrogen derived from fossil fuels), decisions about land-use (hydrogen from biomass), a possible doubling (or more) of the current electricity production capacity with a high penetration of renewable electricity (hydrogen from electrolysis of water), and/or the public acceptability of a large scale nuclear renaissance (hydrogen from electrolysis of water or from thermo-chemical cycles). Any rapid transition to a fully developed hydrogen economy would require a contribution from at least some and possibly all of these sources. Such a transition could result in a marked decrease in carbon dioxide emissions over the long term, but might even result in increased emissions within the shorter term (due to the initial use of hydrogen derived from fossil fuels without carbon dioxide sequestration or from the bulk grid electricity supply resulting in increased load factors and lifetimes of old fossil-fired power plant to meet the increased overall demand). 47 refs., 45 figs., 19 tabs., 3 apps.

Hydrogen adsorption and desorption in carbon nanotube systems and its mechanisms

Energy Technology Data Exchange (ETDEWEB)

Shiraishi, M.; Takenobu, T.; Ata, M. [Materials Laboratories, SONY Corporation, Shin-Sakuragaoka 2-1-1, Hodogaya-ku, 240-0036, Yokohama (Japan); Kataura, H. [Department of Physics, Faculty of Science, Tokyo Metropolitan University, Minami-Osawa, Hachioji, 192-0397, Tokyo (Japan)

2004-04-01

The hydrogen physisorption properties in single-walled carbon nanotube (SWNT) based materials were characterized. The SWNTs were highly purified and three useful pores for hydrogen physisorption were activated. Hydrogen was physisorbed in intra-tube pores at room temperature and the capacity was estimated to be about 0.3-0.4 wt. % at room temperature. The adsorption capacity can be explained by the Langmuir model. The intra-tube pores have large adsorption potential and this induces hydrogen physisorption at comparatively higher temperatures. This fact indicates the importance of fabricating sub-nanometer ordered pores for this phenomena. (orig.)

A synthesis method for cobalt doped carbon aerogels with high surface area and their hydrogen storage properties

Energy Technology Data Exchange (ETDEWEB)

Tian, H.Y.; Buckley, C.E. [Department of Imaging and Applied Physics, Curtin University of Technology, GPO Box U 1987, Perth 6845, WA (Australia); CSIRO National Hydrogen Materials Alliance, CSIRO Energy Centre, 10 Murray Dwyer Circuit, Steel River Estate, Mayfield West, NSW 2304 (Australia); Sheppard, D.A.; Paskevicius, M. [Department of Imaging and Applied Physics, Curtin University of Technology, GPO Box U 1987, Perth 6845, WA (Australia); Hanna, N. [CSIRO Process Science and Engineering, Waterford, WA (Australia)

2010-12-15

Carbon aerogels doped with nanoscaled Co particles were prepared by first coating activated carbon aerogels using a wet-thin layer coating process. The resulting metal-doped carbon aerogels had a higher surface area ({proportional_to}1667 m{sup 2} g{sup -1}) and larger micropore volume ({proportional_to}0.6 cm{sup 3} g{sup -1}) than metal-doped carbon aerogels synthesised using other methods suggesting their usefulness in catalytic applications. The hydrogen adsorption behaviour of cobalt doped carbon aerogel was evaluated, displaying a high {proportional_to}4.38 wt.% H{sub 2} uptake under 4.6 MPa at -196 C. The hydrogen uptake capacity with respect to unit surface area was greater than for pure carbon aerogel and resulted in {proportional_to}1.3 H{sub 2} (wt. %) per 500 m{sup 2} g{sup -1}. However, the total hydrogen uptake was slightly reduced as compared to pure carbon aerogel due to a small reduction in surface area associated with cobalt doping. The improved adsorption per unit surface area suggests that there is a stronger interaction between the hydrogen molecules and the cobalt doped carbon aerogel than for pure carbon aerogel. (author)

Adsorption/oxidation of hydrogen sulfide on nitrogen-containing activated carbons

Energy Technology Data Exchange (ETDEWEB)

Adib, F.; Bagreev, A.; Bandosz, T.J.

2000-02-22

Wood-based activated carbon was modified by impregnation with urea and heat treatment at 450 and 950 C. The chemical and physical properties of materials were determined using acid/base titration, FTIR, thermal analysis, IGC, and sorption of nitrogen. The surface features were compared to those of a commercial urea-modified carbon. Then, the H{sub 2}S breakthrough capacity tests were carried out, and the sorption capacity was evaluated. The results showed that urea-modified sorbents have a capacity similar to that of the received material; however, the conversion of hydrogen sulfide to a water-soluble species is significantly higher. It happens due to a high dispersion of basic nitrogen compounds in the small pores of carbons, where oxidation of hydrogen sulfide ions to sulfur radicals followed by the creation of sulfur oxides and sulfuric acid occurs. It is proposed that the process proceeds gradually, from small pores to larger, and that the degree of microporosity is an important factor.

Carbon catalysts for electrochemical hydrogen peroxide production in acidic media

DEFF Research Database (Denmark)

Čolić, Viktor; Yang, Sungeun; Révay, Zsolt

2018-01-01

Hydrogen peroxide is a commodity chemical, as it is an environmentally friendly oxidant. The electrochemical production of H2O2 from oxygen and water by the reduction of oxygen is of great interest, as it would allow the decentralized, on-site, production of pure H2O2. The ability to run...... the reaction in an acidic electrolyte with high performance is particularly important, as it would allow the use of polymer solid electrolytes and the production of pH-neutral hydrogen peroxide. Carbon catalysts, which are cheap, abundant, durable and can be highly selective show promise as potential catalysts...... for such systems. In this work, we examine the electrocatalytic performance and properties of seven commercially available carbon materials for H2O2 production by oxygen electroreduction. We show that the faradaic efficiencies for the reaction lie in a wide range of 18-82% for different carbon catalysts. In order...

Hydrogenated amorphous carbon next deposit after heat treatment

International Nuclear Information System (INIS)

Salancon, E.; Durbeck, T.; Schwarz-Selinger, T.; Jacob, W.

2006-01-01

One of the main safety problems in the ITER tokamak project is the tritium adsorption in the reactor walls and in particular the deposits which appear after the plasma discharge. These deposits are amorphous hydrogenated carbon films, type polymer (soft a-C:H). The heating of these deposits with a pulse laser is a proposed solution for the tritium desorption. Meanwhile, Gibson and al show that in experimental conditions, products are deposed on the walls before entering the mass spectrometer. The authors present thermo-desorption spectra of different amorphous carbon films. (A.L.B.)

A Low-Stress, Elastic, and Improved Hardness Hydrogenated Amorphous Carbon Film

Directory of Open Access Journals (Sweden)

Qi Wang

2015-01-01

Full Text Available The evolution of hydrogenated amorphous carbon films with fullerene-like microstructure was investigated with a different proportion of hydrogen supply in deposition. The results showed at hydrogen flow rate of 50 sccm, the deposited films showed a lower compressive stress (lower 48.6%, higher elastic recovery (higher 19.6%, near elastic recovery rate 90%, and higher hardness (higher 7.4% compared with the films deposited without hydrogen introduction. Structural analysis showed that the films with relatively high sp2 content and low bonded hydrogen content possessed high hardness, elastic recovery rate, and low compressive stress. It was attributed to the curved graphite microstructure, which can form three-dimensional covalently bonded network.

Fast synthesis of multilayer carbon nanotubes from camphor oil as an energy storage material.

Science.gov (United States)

TermehYousefi, Amin; Bagheri, Samira; Shinji, Kawasaki; Rouhi, Jalal; Rusop Mahmood, Mohamad; Ikeda, Shoichiro

2014-01-01

Among the wide range of renewable energy sources, the ever-increasing demand for electricity storage represents an emerging challenge. Utilizing carbon nanotubes (CNTs) for energy storage is closely being scrutinized due to the promising performance on top of their extraordinary features. In this work, well-aligned multilayer carbon nanotubes were successfully synthesized on a porous silicon (PSi) substrate in a fast process using renewable natural essential oil via chemical vapor deposition (CVD). Considering the influx of vaporized multilayer vertical carbon nanotubes (MVCNTs) to the PSi, the diameter distribution increased as the flow rate decreased in the reactor. Raman spectroscopy results indicated that the crystalline quality of the carbon nanotubes structure exhibits no major variation despite changes in the flow rate. Fourier transform infrared (FT-IR) spectra confirmed the hexagonal structure of the carbon nanotubes because of the presence of a peak corresponding to the carbon double bond. Field emission scanning electron microscopy (FESEM) images showed multilayer nanotubes, each with different diameters with long and straight multiwall tubes. Moreover, the temperature programmed desorption (TPD) method has been used to analyze the hydrogen storage properties of MVCNTs, which indicates that hydrogen adsorption sites exist on the synthesized multilayer CNTs.

Fast Synthesis of Multilayer Carbon Nanotubes from Camphor Oil as an Energy Storage Material

Science.gov (United States)

TermehYousefi, Amin; Bagheri, Samira; Shinji, Kawasaki; Rouhi, Jalal; Rusop Mahmood, Mohamad; Ikeda, Shoichiro

2014-01-01

Among the wide range of renewable energy sources, the ever-increasing demand for electricity storage represents an emerging challenge. Utilizing carbon nanotubes (CNTs) for energy storage is closely being scrutinized due to the promising performance on top of their extraordinary features. In this work, well-aligned multilayer carbon nanotubes were successfully synthesized on a porous silicon (PSi) substrate in a fast process using renewable natural essential oil via chemical vapor deposition (CVD). Considering the influx of vaporized multilayer vertical carbon nanotubes (MVCNTs) to the PSi, the diameter distribution increased as the flow rate decreased in the reactor. Raman spectroscopy results indicated that the crystalline quality of the carbon nanotubes structure exhibits no major variation despite changes in the flow rate. Fourier transform infrared (FT-IR) spectra confirmed the hexagonal structure of the carbon nanotubes because of the presence of a peak corresponding to the carbon double bond. Field emission scanning electron microscopy (FESEM) images showed multilayer nanotubes, each with different diameters with long and straight multiwall tubes. Moreover, the temperature programmed desorption (TPD) method has been used to analyze the hydrogen storage properties of MVCNTs, which indicates that hydrogen adsorption sites exist on the synthesized multilayer CNTs. PMID:25258714

Hydrogen adsorption on activated carbon nanotubes with an atomic-sized vanadium catalyst investigated by electrical resistance measurements

International Nuclear Information System (INIS)

Im, Ji Sun; Yun, Jumi; Kang, Seok Chang; Lee, Sung Kyu; Lee, Young-Seak

2012-01-01

Activated multi-walled carbon nanotubes were prepared with appended vanadium as a hydrogen storage medium. The pore structure was significantly improved by an activation process that was studied using Raman spectroscopy, field emission transmission electron microscopy and pore analysis techniques. X-ray photoelectron spectroscopy and X-ray diffraction results reveal that the vanadium catalyst was introduced into the carbon nanotubes in controlled proportions, forming V 8 C 7 . The improved pore structure functioned as a path through the carbon nanotubes that encouraged hydrogen molecule adsorption, and the introduced vanadium catalyst led to high levels of hydrogen storage through the dissociation of hydrogen molecules via the spill-over phenomenon. The hydrogen storage behavior was investigated by electrical resistance measurements for the hydrogen adsorbed on a prepared sample. The proposed mechanism of hydrogen storage suggests that the vanadium catalyst increases not only the amount of hydrogen that is stored but also the speed at which it is stored. A hydrogen storage capacity of 2.26 wt.% was achieved with the activation effects and the vanadium catalyst at 30 °C and 10 MPa.

Options for CO2-lean hydrogen export from Norway to Germany

International Nuclear Information System (INIS)

Stiller, Christoph; Buenger, Ulrich; Svensson, Ann Mari; Moeller-Holst, Steffen; Espegren, Kari Aamodt; Holm, Oeystein Bindesboell; Tomasgaard, Asgeir

2008-01-01

Norway is a nation with an abundant supply of energy, both from fossil and renewable resources. Due to limited domestic demand, Norway is today exporting large amounts of petroleum products. For the future, various options for export of CO 2 -lean energy exist, both from Northern and Southern Norway, and both from fossil sources (including carbon capture and storage), and renewable energies (particularly wind power). Transport vectors are hydrogen pipelines, liquid hydrogen ships and HVDC cables, and a plausible customer is central Europe due to its proximity, high population density and lack of domestic energy resources. Within the framework of the ''NorWays'' project, various options to deliver energy for hydrogen-based transportation from Norway to Germany were studied. Eight CO 2 -lean well-to-wheel energy export chains were evaluated with respect to efficiency, GHG emissions and other environmental impacts, costs and utilisation of Norwegian R and D experience. In the chosen scenarios, energy export via hydrogen pipelines and ships appeared energetically and economically interesting against existing approaches as NG and electricity export. Furthermore, increased utilisation of Norwegian R and D experience and higher value creation is anticipated by the export of a higher refined product. (author)

Nanosized Magnesium Electrochemically Deposited on a Carbon Nanotubes Suspension: Synthesis and Hydrogen Storage

Energy Technology Data Exchange (ETDEWEB)

Shen, Chaoqi; Aguey-Zinsou, Kondo-Francois, E-mail: f.aguey@unsw.edu.au [MERLin, School of Chemical Engineering, The University of New South Wales, Sydney, NSW (Australia)

2017-10-17

Herein, we report on a novel method for deposition of magnesium (Mg) nanoparticles at the surface of carbon materials. Through the suspension of carbon nanotubes (CNTs) in an electrolyte containing di-n-butylmagnesium as a precursor, Mg nanoparticles were effectively deposited at the surface of the CNTs as soon as these touched the working electrode. Through this process, CNTs supported Mg particles as small as 1 nm were synthesized and the distribution of the nanoparticles was found to be influenced by the concentration of the CNTs in the electrolyte. Hydrogenation of these nanoparticles at 100°C was found to lead to low temperature hydrogen release starting at 150°C, owing to shorter diffusion paths and higher hydrogen mobility in small Mg particles. However, these hydrogen properties drastically degraded as soon as the hydrogenation temperature exceeded 200°C and this may be related to the low melting temperature of ultrasmall Mg particles.

Nanosized Magnesium Electrochemically Deposited on a Carbon Nanotubes Suspension: Synthesis and Hydrogen Storage

Directory of Open Access Journals (Sweden)

Chaoqi Shen

2017-10-01

Full Text Available Herein, we report on a novel method for deposition of magnesium (Mg nanoparticles at the surface of carbon materials. Through the suspension of carbon nanotubes (CNTs in an electrolyte containing di-n-butylmagnesium as a precursor, Mg nanoparticles were effectively deposited at the surface of the CNTs as soon as these touched the working electrode. Through this process, CNTs supported Mg particles as small as 1 nm were synthesized and the distribution of the nanoparticles was found to be influenced by the concentration of the CNTs in the electrolyte. Hydrogenation of these nanoparticles at 100°C was found to lead to low temperature hydrogen release starting at 150°C, owing to shorter diffusion paths and higher hydrogen mobility in small Mg particles. However, these hydrogen properties drastically degraded as soon as the hydrogenation temperature exceeded 200°C and this may be related to the low melting temperature of ultrasmall Mg particles.

Nuclear Energy and Renewables interaction: System Effects in Low-carbon Electricity Systems

International Nuclear Information System (INIS)

Keppler, Jan Horst; Cometto, Marco

2013-01-01

This report presents a synthesis of the OECD/NEA study 'Nuclear Energy and Renewables: System Effects in Low-carbon Electricity Systems'. It addresses the increasingly important interactions of variable renewables and dispatchable energy technologies, such as nuclear power, in terms of their effects on electricity systems. These effects add costs to the production of electricity, which are not usually transparent. The report recommends that decision-makers should take into account such system costs and internalise them according to a 'generator pays' principle, which is currently not the case. Analysing data from six OECD/NEA countries, the study finds that including the system costs of variable renewables at the level of the electricity grid increases the total costs of electricity supply by up to one-third, depending on technology, country and penetration levels. In addition, it concludes that, unless the current market subsidies for renewables are altered, dispatchable technologies will increasingly not be replaced as they reach their end of life and consequently security of supply will suffer. This implies that significant changes in management and cost allocation will be needed to generate the flexibility required for an economically viable coexistence of nuclear energy and renewables in increasingly de-carbonised electricity systems

Comparative study of hydrogen and methanol as energy carriers

Energy Technology Data Exchange (ETDEWEB)

Johansson, Anna

1998-06-01

This report has been written with the purpose to compare hydrogen and methanol, with gasoline, as energy carriers for new energy systems in the future. This energy system must satisfy the demands for sustainable development. The report focuses on motor vehicle applications. A few different criteria has been developed to help form the characterisation method. The criteria proposed in this thesis are developed for an environmental comparison mainly based on emissions from combustion. The criteria concerns the following areas: Renewable resources, The ozone layer, The greenhouse effect, The acidification, and Toxic substances. In many ways, hydrogen may seem as a very good alternative compared with gasoline and diesel oil. Combustion of hydrogen in air results in water and small amounts of oxides of nitrogen. In this report, hydrogen produced from renewable resources is investigated. This is necessary to fulfill the demands for sustainable development. Today, however, steam reforming of fossil fuels represent 99% of the hydrogen production market. Problem areas connected with hydrogen use are for instance storage and distribution. Methanol has many advantages, while comparing methanol and gasoline, like lower emissions of nitrogen oxides and hydrocarbons, limited emissions of carbon dioxide and no sulphur content. Methanol can be produced from many different resources, for example natural gas, naphtha, oil, coal or peat, and biomass. To meet demands for sustainable production, methanol has to be produced from biomass Examination paper. 32 refs, 20 figs, 13 tabs

High Performance, Low Cost Hydrogen Generation from Renewable Energy

Energy Technology Data Exchange (ETDEWEB)

Ayers, Katherine [Proton OnSite; Dalton, Luke [Proton OnSite; Roemer, Andy [Proton OnSite; Carter, Blake [Proton OnSite; Niedzwiecki, Mike [Proton OnSite; Manco, Judith [Proton OnSite; Anderson, Everett [Proton OnSite; Capuano, Chris [Proton OnSite; Wang, Chao-Yang [Penn State University; Zhao, Wei [Penn State University

2014-02-05

Renewable hydrogen from proton exchange membrane (PEM) electrolysis is gaining strong interest in Europe, especially in Germany where wind penetration is already at critical levels for grid stability. For this application as well as biogas conversion and vehicle fueling, megawatt (MW) scale electrolysis is required. Proton has established a technology roadmap to achieve the necessary cost reductions and manufacturing scale up to maintain U.S. competitiveness in these markets. This project represents a highly successful example of the potential for cost reduction in PEM electrolysis, and provides the initial stack design and manufacturing development for Proton’s MW scale product launch. The majority of the program focused on the bipolar assembly, from electrochemical modeling to subscale stack development through prototyping and manufacturing qualification for a large active area cell platform. Feasibility for an advanced membrane electrode assembly (MEA) with 50% reduction in catalyst loading was also demonstrated. Based on the progress in this program and other parallel efforts, H2A analysis shows the status of PEM electrolysis technology dropping below $3.50/kg production costs, exceeding the 2015 target.

Thermogravimetric measurement of hydrogen storage in carbon-based materials: promise and pitfalls

International Nuclear Information System (INIS)

Pinkerton, F.E.; Wicke, B.G.; Olk, C.H.; Tibbetts, G.G.; Meisner, G.P.; Meyer, M.S.; Herbst, J.F.

2000-01-01

We have used a thermogravimetric analyzer (TGA) to measure the hydrogen absorption capacity of a variety of carbon-based storage materials, including Li- and K-intercalated graphite and Li-doped multi-wall nanotubes. The TGA uses weight gain/loss as a function of time and temperature to monitor hydrogen absorption/desorption in flowing hydrogen gas. Creating and maintaining a contaminant-free atmosphere is critical to the accurate TGA measurement of hydrogen absorption in carbon-based materials; even low concentrations of impurity gases such as O 2 or H 2 O are sufficient to masquerade as hydrogen absorption. We will discuss examples of this effect relevant to recent reports of hydrogen storage appearing in the literature. The precautions required are non-trivial. In our TGA, for instance, about 16% of the original atmosphere remains after a two-hour purge; at least 15 hours is required to fully purge the apparatus. Furthermore, we cover the TGA with a protective atmosphere enclosure during sample loading to minimize the introduction of impurity gases. With these precautions it is possible to unambiguously measure hydrogen storage. For example, we have determined the hydrogen absorption capacity of our K-intercalated graphite samples to be 1.3 wt% total hydrogen absorption above 50 o C, of which 0.2 wt% can be reproducibly recovered with temperature cycling. With due care, TGA measurements provide complementary information to that obtained from standard pressure techniques for measuring hydrogen sorption, which rely on measuring the loss of gas pressure in a known volume. Taken together, TGA and pressure measurements provide a powerful combination for determining verifiable hydrogen storage capacity. (author)

A comparison between renewable transport fuels that can supplement or replace biofuels in a 100% renewable energy system

DEFF Research Database (Denmark)

Connolly, David; Mathiesen, Brian Vad; Ridjan, Iva

2014-01-01

Identifying renewable energy alternatives in transport is particularly complicated, since the end-user can vary from a single-person car to a cargo ship. The aim of this paper is to aid this process by comparing 7 different methods for producing transport fuels in terms of the resources required......, the conversion processes used, the fuel obtained, and the transport demand met. The results indicate that electricity should be prioritised as a transport fuel in the future since it is the most efficient and cheapest pathway. However, since electricity is not suitable for all modes of transport, some form...... of energy dense fuel is also necessary. The results in this paper suggest that this fuel will be produced by hydrogenating either biomass or carbon dioxide, depending on the residual biomass available. Biomass gasification, steam electrolysis, and carbon capture are key technologies in the future...

Research Progress on the Indirect Hydrogenation of Carbon Dioxide to Methanol.

Science.gov (United States)

Du, Xian-Long; Jiang, Zheng; Su, Dang Sheng; Wang, Jian-Qiang

2016-02-19

Methanol is a sustainable source of liquid fuels and one of the most useful organic chemicals. To date, most of the work in this area has focused on the direct hydrogenation of CO2 to methanol. However, this process requires high operating temperatures (200-250 °C), which limits the theoretical yield of methanol. Thus, it is desirable to find a new strategy for the efficient conversion of CO2 to methanol at relatively low reaction temperatures. This Minireview seeks to outline the recent advances on the indirect hydrogenation of CO2 to methanol. Much emphasis is placed on discussing specific systems, including hydrogenation of CO2 derivatives (organic carbonates, carbamates, formates, cyclic carbonates, etc.) and cascade reactions, with the aim of critically highlighting both the achievements and remaining challenges associated with this field. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Low-cost metal oxide activated carbon prepared and modified by microwave heating method for hydrogen storage

Energy Technology Data Exchange (ETDEWEB)

Moradi, S. E. [Islamic Azad University, Sari (Iran, Islamic Republic of)

2014-09-15

Novel microporous activated carbon (MAC) with high surface area and pore volume has been synthesized by microwave heating. Iron oxide nanoparticles were loaded into MAC by using Fe(NO{sub 3}){sub 3}·9H{sub 2}O followed by microwave irradiation for up to five minutes. The surface modified microporous activated carbon was characterized by BET, XRD, SEM and thermogravimetric examinations. Adsorption data of H{sub 2} on the unmodified and modified MACs were collected with PCT method for a pressure range up to 120 bar at 303 K. Greater hydrogen adsorption was observed on the carbon adsorbents doped with 1.45 wt% of iron oxide nanoparticle loaded due to the joint properties of hydrogen adsorption on the carbon surface and the spill-over of hydrogen molecules into carbon structures.

Morphology, Microstructure, and Hydrogen Content of Carbon Nanostructures Obtained by PECVD at Various Temperatures

Directory of Open Access Journals (Sweden)

M. Acosta Gentoiu

2017-01-01

Full Text Available Carbon nanostructures were obtained by acetylene injection into an argon plasma jet in the presence of hydrogen. The samples were synthesized in similar conditions, except that the substrate deposition temperatures TD were varied, ranging from 473 to 973 K. A strong dependence of morphology, structure, and graphitization upon TD was found. We obtained vertical aligned carbon nanotubes (VA-CNTs at low temperatures as 473 K, amorphous carbon nanoparticles (CNPs at temperatures from about 573 to 673 K, and carbon nanowalls (CNWs at high temperatures from 773 to 973 K. Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, elastic recoil detection analysis, X-ray photoelectron spectroscopy, and Raman spectroscopy were used to substantiate the differences in these material types. It is known that hydrogen concentration modifies strongly the properties of the materials. Different concentrations of hydrogen-bonded carbon could be identified in amorphous CNP, VA-CNT, and CNW. Also, the H : C ratios along depth were determined for the obtained materials.

Renewable energy

International Nuclear Information System (INIS)

Berghmans, J.

1994-01-01

Renewable energy sources have a small environmental impact and can be easily integrated within existing structures. Moreover, the use of renewable energy sources can contribute to achieve a zero emission of carbon dioxide by 2100, provided an efficient environmental policy during the next 40 years. This includes a correct pricing policy of renewable energy sources with respect to nuclear energy and fossil fuel. The latter energy sources have been favoured in the past. In addition, an open market policy, the restructuring or conversion of existing international energy institutes, and international treaties for the protection of the natural environment are needed in view of achieving the zero carbon dioxide emission objective. (A.S.)

Hydrogen storage in single-wall carbon nano-tubes by means of laser excitation

International Nuclear Information System (INIS)

Oksengorn, B.

2010-01-01

A new mode for hydrogen adsorption and storage in single-wall carbon nano-tubes is used, on the basis of laser excitation. Remember that this method has been useful to obtain, in the case of the fullerene C 60 , many complex C 60 -atoms or C 60 -molecules, where atoms or molecular particles are trapped inside the C 60 -molecules. We think this method might be important to store many hydrogen molecules inside carbon nano-tubes. (author)

Assessment of hydrogen storage systems as a means of integrating electricity from renewable energies; Bewertung von Wasserstoffspeichersystemen zur Integration von Strom aus erneuerbaren Energien

Energy Technology Data Exchange (ETDEWEB)

Michaelis, Julia; Genoese, Fabio; Wietschel, Martin [Fraunhofer-Institut fuer System- und Innovationsforschung (ISI), Karlsruhe (Germany)

2013-06-15

Hydrogen storage is a possible option for an improved integration of renewable energies into the electricity supply system. Similarly to other technical storage options it is faced with the challenge of having to be economically viable. Compared with other storage media hydrogen has the virtue of being versatile. This has a significant impact on assessments of its profitability.

Simulation of carbon sputtering due to molecular hydrogen impact

International Nuclear Information System (INIS)

Laszlo, J.

1993-01-01

Simulated results are compared to experimental data on the sputtering yield of carbon due to atomic and to molecular hydrogen impact. The experimental sputtering yields of carbon (graphite) due to low energy hydrogen bombardment have been found to be higher than the simulated ones. Efforts are made to obtain high enough simulated yields by considering the formation of dimer, H 2 and D 2 molecules in the primary beam. The molecular beam model applies full neutralization and full dissociation at the surface. The simulation of sputtering yields of target materials up to Z 2 ≤ 30 is also included for the low primary energy regime for deuterium projectiles. It is found that, although the sputtering yields really tend to increase, the effect of molecule formation in the beam in itself cannot be made responsible for the deviation between measured and simulated sputtering yields. (orig.)

Hydrogen from nuclear energy and the impact on climate change

International Nuclear Information System (INIS)

Duffey, R.B.; Miller, A.I.; Poehnell, T.G.

2001-01-01

The two major candidates for hydrogen production include nuclear power and other renewable energy sources. However, hydrogen produced by steam reforming of natural gas offers little advantage in total cycle greenhouse gas (GHG) emissions over hybrid internal combustion engine (ICE) technology. Only nuclear power offers the possibility of cutting GHG emissions significantly and to economically provide electricity for traditional applications and by producing hydrogen for its widespread use in the transportation sector. Using nuclear energy to produce hydrogen for transportation fuel, doubles or triples nuclear's capacity to reduce GHG emissions. An analysis at the Atomic Energy of Canada shows that a combination of hydrogen fuel and nuclear energy can stabilize GHG emissions and climate change for a wide range of the latest scenarios presented by the Intergovernmental Panel on Climate Change. The technology for replacing hydrocarbon fuels with non-polluting hydrogen exists with nuclear power, electrolysis and fuel cells, using electric power grids for distribution. It was emphasized that a move toward total emissions-free transportation will be a move towards solving the negative effects of climate change. This paper illustrated the trends between global economic and atmospheric carbon dioxide concentrations. Low carbon dioxide emission energy alternatives were discussed along with the sources of hydrogen and the full cycle assessment results in reduced emissions. It was shown that deploying 20 CANDU NPPs (of 690 MW (e) net each) would fuel 13 million vehicles with the effect of levelling of carbon dioxide emissions from transportation between 2020 to 2030. 13 refs., 2 tabs., 3 figs

A nano-engineered graphene/carbon nitride hybrid for photocatalytic hydrogen evolution

Institute of Scientific and Technical Information of China (English)

Xiaobo Li; Yao Zheng; Anthony F.Masters; Thomas Maschmeyer

2016-01-01

A metal-free photocatalytic hydrogen evolution system was successfully fabricated using heteroatom doped graphene materials as electron-transfer co-catalysts and carbon nitride as a semiconductor.The catalytic role of graphene is significantly dependent on the heteroatom dopant of the graphene,such as O,S,B,N doped/undoped graphene co-catalysts,and N-graphene shows the best catalytic hydrogen evolution rate.

Renewable Energy and Hydrogen System Concepts for Remote Communities in the West Nordic Region

Energy Technology Data Exchange (ETDEWEB)

Ulleberg, Oeystein; Moerkved, Andreas

2008-02-25

In 2003 the Nordic Council of Ministers granted the funding for the first of several studies on renewable energy and hydrogen (RE/H2) energy systems for remote communities in the West Nordic region. The objective with this report is to summarize the main findings from Phase II and III of the West Nordic project. The island Nolsoy, Faroe Islands, was selected as a case study. The main conclusion is that it makes sense to design a wind/diesel-system with thermal storage, both from a techno-economical and environmental point of view. Such systems can have close to 100% local utilization of the wind energy, and can cover up to 75% of the total annual electricity demand and 35% of the annual heat demand at a cost of energy around 0.07 - 0.09 euro/kWh. The introduction of a hydrogen system is technically feasible, but doubles the overall investment costs

Sustainable hybrid photocatalysts: titania immobilized on carbon materials derived from renewable and biodegradable resources

Science.gov (United States)

This review comprises the preparation, properties and heterogeneous photocatalytic applications of TiO2 immobilized on carbon materials derived from earth-abundant, renewable and biodegradable agricultural residues and sea food waste resources. The overview provides key scientifi...

Hydrogen Generation from Sugars via Aqueous-Phase Reforming

International Nuclear Information System (INIS)

Randy D Cortright

2006-01-01

Virent Energy Systems, Inc. is commercializing the Aqueous Phase Reforming (APR) process that allows the generation of hydrogen-rich gas streams from biomass-derived compounds such as glycerol, sugars, and sugar alcohols. The APR process is a unique method that generates hydrogen from aqueous solutions of these oxygenated compounds in a single step reactor process compared to the three or more reaction steps required for hydrogen generation via conventional processes that utilize non-renewable fossil fuels. The key breakthrough of the APR process is that the reforming of these aqueous solutions is done in the liquid phase. The patented APR process occurs at temperatures (150 C to 270 C) where the water-gas shift reaction is favorable, making it possible to generate hydrogen with low amounts of CO in a single chemical reactor. Furthermore, the APR process occurs at pressures (typically 15 to 50 bar) where the hydrogen-rich effluent can be effectively purified using either membrane technology or pressure swing adsorption technology. The utilization of biomass-based compounds allows the APR process to be a carbon neutral method to generate hydrogen. In the near term, the feed-stock of interest is waste glycerol that is being generated in large quantities as a byproduct in the production of bio-diesel. Virent has developed the APR system for on-demand generation of hydrogen-rich fuel gas from either glycerol or sorbitol (the sugar alcohol formed by hydrogenation of glucose) to fuel a stationary internal combustion engine driven generator (10 kW). Under a USDOE funded project, Virent is currently developing the APR process to generate high yields of hydrogen from corn-derived glucose. This project objective is to achieve the DOE 2010 cost target for distributed production from renewable liquid fuels of 3.60 dollars/gge (gasoline gallon equivalent) delivered. (authors)

Thermodynamic diagrams for high temperature plasmas of air, air-carbon, carbon-hydrogen mixtures, and argon

CERN Document Server

Kroepelin, H; Hoffmann, K-U

2013-01-01

Thermodynamic Diagrams for High Temperature Plasmas of Air, Air-Carbon, Carbon-Hydrogen Mixtures, and Argon provides information relating to the properties of equilibrium gas plasmas formed from hydrocarbons, from air without argon, from pure argon, and from mixtures of air and carbon at various compositions, temperatures and pressures. The data are presented in graphical rather than tabular form to provide a clearer picture of the plasma processes investigated. This book is composed of four chapters, and begins with the introduction to the characteristics of plasmas, with emphasis on their th

Hydrogen production by renewable energies. Final report of the integrated research program 4.1; Production d'hydrogene par des energies renouvelables. Rapport final du programme de recherche integree 4.1

Energy Technology Data Exchange (ETDEWEB)

NONE

2004-07-01

The aim of this PRI is to study and to develop methods of hydrogen production based on the renewable energies, without greenhouse gases emission in order to implement clean processes in the framework of a sustainable development. Two approaches are proposed. The first one uses microorganisms in condition of hydrogen production (micro-algae). The second one is based on the bio-mimetism approaches aiming to reproduce artificially the biological mechanisms of the photosynthesis leading to water decomposition. (A.L.B.)

The US department of energy programme on hydrogen production

International Nuclear Information System (INIS)

Paster, M.D.

2004-01-01

production will be more cost effective, but distributed production will still play a role. Utilization of nuclear and renewable technologies inherently addresses greenhouse gas emission directly. The use of fossil fuels requires the development of carbon dioxide sequestration technology to enable a hydrogen economy that also addresses climate change concerns. Ultimately, a spectrum of feedstocks and technologies for hydrogen production will be necessary to address energy security and climate change concerns. The DOE Hydrogen Program will address multiple feedstock and technology options to provide effective and efficient hydrogen production for the short term and the long term. The U. S. DOE Hydrogen Program is contained within the Offices of Nuclear Energy, Fossil Energy, and Energy Efficiency and Renewable Energy that are now working synergistically together to accomplish the overall program goals. The potential benefits of a hydrogen economy are immense. They include increased energy security through the use of domestic and renewable energy feedstocks and a dramatic reduction in green house gas and other criteria air pollutants. (author)

A smart strategy to fabricate Ru nanoparticle inserted porous carbon nanofibers as highly efficient levulinic acid hydrogenation catalysts

Energy Technology Data Exchange (ETDEWEB)

Yang, Ying; Sun, Cheng-Jun; Brown, Dennis E.; Zhang, Liqiang; Yang, Feng; Zhao, Hairui; Wang, Yue; Ma, Xiaohui; Zhang, Xin; Ren, Yang

2016-01-01

Herein, we first put forward a smart strategy to in situ fabricate Ru nanoparticle (NP) inserted porous carbon nanofibers by one-pot conversion of Ru-functionalized metal organic framework fibers. Such fiber precursors are skillfully constructed by cooperative assembly of different proportional RuCl3 and Zn(Ac)2·2H2O along with trimesic acid (H3BTC) in the presence of N,N-dimethylformamide. The following high-temperature pyrolysis affords uniform and evenly dispersed Ru NPs (ca. 12-16 nm), which are firmly inserted into the hierarchically porous carbon nanofibers formed simultaneously. The resulting Ru-carbon nanofiber (Ru-CNF) catalysts prove to be active towards the liquid-phase hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL), a biomass-derived platform molecule with wide applications in the preparation of renewable chemicals and liquid transportation fuels. The optimal GVL yield of 96.0% is obtained, corresponding to a high activity of 9.23 molLAh–1gRu–1, 17 times of that using the commercial Ru/C catalyst. Moreover, the Ru-CNF catalyst is extremely stable, and can be cycled up to 7 times without significant loss of reactivity. Our strategy demonstrated here reveals new possibilities to make proficient metal catalysts, and provides a general way to fabricate metal-carbon nanofiber composites available for other applications.

Carbon dioxide reduction in housing: experiences in urban renewal projects in the Netherlands

NARCIS (Netherlands)

Waals, F.M. van der; Vermeulen, W.J.V.; Glasbergen, P.

2003-01-01

It is increasingly being recognised that the housing sector can contribute to reductions in the levels of carbon dioxide (CO2 ). The renewal of existing residential areas offers opportunities to reduce CO2 emissions. However, technical options for CO2-reduction, such as insulation, solar energy,

Analysis of economic and infrastructure issues associated with hydrogen production from nuclear energy

International Nuclear Information System (INIS)

Summers, W.A.; Gorensek, M.B.; Danko, E.; Schultz, K.R.; Richards, M.B.; Brown, L.C.

2004-01-01

Consideration is being given to the large-scale transition of the world's energy system from one based on carbon fuels to one based on the use of hydrogen as the carrier. This transition is necessitated by the declining resource base of conventional oil and gas, air quality concerns, and the threat of global climate change linked to greenhouse gas emissions. Since hydrogen can be produced from water using non-carbon primary energy sources, it is the ideal sustainable fuel. The options for producing the hydrogen include renewables (e.g. solar and wind), fossil fuels with carbon sequestration, and nuclear energy. A comprehensive study has been initiated to define economically feasible concepts and to determine estimates of efficiency and cost for hydrogen production using next generation nuclear reactors. A unique aspect of the study is the assessment of the integration of a nuclear plant, a hydrogen production process and the broader infrastructure requirements. Hydrogen infrastructure issues directly related to nuclear hydrogen production are being addressed, and the projected cost, value and end-use market for hydrogen will be determined. The infrastructure issues are critical, since the combined cost of storing, transporting, distributing, and retailing the hydrogen product could well exceed the cost of hydrogen production measured at the plant gate. The results are expected to be useful in establishing the potential role that nuclear hydrogen can play in the future hydrogen economy. Approximately half of the three-year study has been completed. Results to date indicate that nuclear produced hydrogen can be competitive with hydrogen produced from natural gas for use at oil refineries or ammonia plants, indicating a potential early market opportunity for large-scale centralized hydrogen production. Extension of the hydrogen infrastructure from these large industrial users to distributed hydrogen users such as refueling stations and fuel cell generators could

Catalytic applications of immobilized ionic liquids for synthesis of cyclic carbonates from carbon dioxide and epoxides

International Nuclear Information System (INIS)

Kim, Dong-Woo; Roshan, Roshith; Tharun, Jose; Cherian, Amal; Park, Dae-Won

2013-01-01

The catalytic applicability of ionic liquids immobilized on various support materials such as silica, polystyrene and biopolymers in the cycloaddition of carbon dioxide with epoxides is reviewed in this work. Comparisons of the catalytic efficiency of these various catalysts have been done from the aspect of turnover number and reusability. The studies revealed that ionic liquids or support materials possessing hydrogen bonding capable groups exhibited enhanced catalytic activity towards cyclic carbonate synthesis. Moreover, the increased quest towards environmentally benign materials has renewed the search for biocompatible materials as support for ionic liquids

Method of carbon dioxide-free hydrogen production from hydrocarbon decomposition over metal salts

Science.gov (United States)

Erlebacher, Jonah; Gaskey, Bernard

2017-10-03

A process to decompose methane into carbon (graphitic powder) and hydrogen (H.sub.2 gas) without secondary production of carbon dioxide, employing a cycle in which a secondary chemical is recycled and reused, is disclosed.

Dependence of hydrogen storage characteristics of mechanically milled carbon materials on their host structures

International Nuclear Information System (INIS)

Shindo, K.; Kondo, T.; Sakurai, Y.

2004-01-01

We investigated whether the hydrogen storage characteristics of carbon materials prepared by mechanical milling in an H 2 atmosphere were dependent on their host structures. We used natural graphite (NG) and activated carbon fibers (ACF) and compared them with activated carbon (AC) powders. The XRD patterns of NG and ACF milled for over 20 h and SEM images of these samples milled for 80 h were almost the same as those of AC. The hydrogen storage capacities of NG and ACF estimated by the inert gas fusion-thermal conductivity method increased with the mechanical milling time up to 10 h and showed little milling time dependence thereafter. The capacities of NG and ACF reached about 3.0 wt.% and were similar to that of AC. However, it should be noted that the hydrogen storage mechanism of NG and ACF mechanically milled in an H 2 atmosphere might be different because the changes in their specific surface areas with milling time were opposite. Thermal desorption mass spectroscopy (TDS) revealed that the desorption spectra of the hydrogen molecules (mass number=2) of NG and ACF milled for 10 h in the same way as AC contained two peaks at about 500 and 800 deg. C. The desorption activation energies of hydrogenated NG and ACF at these peaks calculated from a Kissinger plot were almost with the same as those of hydrogenated AC. This suggests that the state of the hydrogen trapped in the structural defects in NG introduced by the mechanical milling may be almost the same as that of AC. In addition, we assumed the possibility that the state of the hydrogen in ACF hydrogenated by mechanical milling could be almost the same as that in hydrogenated AC. We considered that the nanocarbon materials hydrogenated under our milling conditions had very similar physical shapes and hydrogen storage capacities, independent of their host structures

Renewable and low-carbon energies as mitigation options of climate change for China

NARCIS (Netherlands)

Urban, F.; Benders, R. M. J.; Moll, H. C.

This article discusses how renewable and low-carbon energies can serve as mitigation options of climate change in China's power sector. Our study is based on scenarios developed in PowerPlan, a bottom-up model simulating a countries' power sector and its emissions. We first adjusted the model to

Carbon-tuned bonding method significantly enhanced the hydrogen storage of BN-Li complexes.

Science.gov (United States)

Deng, Qing-ming; Zhao, Lina; Luo, You-hua; Zhang, Meng; Zhao, Li-xia; Zhao, Yuliang

2011-11-01

Through first-principles calculations, we found doping carbon atoms onto BN monolayers (BNC) could significantly strengthen the Li bond on this material. Unlike the weak bond strength between Li atoms and the pristine BN layer, it is observed that Li atoms are strongly hybridized and donate their electrons to the doped substrate, which is responsible for the enhanced binding energy. Li adsorbed on the BNC layer can serve as a high-capacity hydrogen storage medium, without forming clusters, which can be recycled at room temperature. Eight polarized H(2) molecules are attached to two Li atoms with an optimal binding energy of 0.16-0.28 eV/H(2), which results from the electrostatic interaction of the polarized charge of hydrogen molecules with the electric field induced by positive Li atoms. This practical carbon-tuned BN-Li complex can work as a very high-capacity hydrogen storage medium with a gravimetric density of hydrogen of 12.2 wt%, which is much higher than the gravimetric goal of 5.5 wt % hydrogen set by the U.S. Department of Energy for 2015.

The metal-carbon-fluorine system for improving hydrogen storage by using metal and fluorine with different levels of electronegativity

Energy Technology Data Exchange (ETDEWEB)

Im, Ji Sun; Lee, Young-Seak [Department of Fine Chemical Engineering and Applied Chemistry, BK21-E2M, Chungnam National University, Daejeon 305-764 (Korea); Park, Soo-Jin [Department of Chemistry, Inha University, Incheon 402-751 (Korea)

2009-02-15

In order to improve the capacity of hydrogen storage using activated carbon nanofibers, metal and fluorine were introduced into the activated carbon nanofibers by electrospinning, heat treatment, and direct fluorination. The pore structure of the samples was developed by the KOH activation process and investigated using nitrogen isotherms and micropore size distribution. The specific surface area and total pore volume approached 2800 m{sup 2}/g and 2.7 cc/g, respectively. Because of the electronegativity gap between the two elements (metal and fluorine), the electron of a hydrogen molecule can be attracted to one side. This reaction effectively guides the hydrogen molecule into the carbon nanofibers. The amount of hydrogen storage was dramatically increased in this metal-carbon-fluorine system; hydrogen content was as high as 3.2 wt%. (author)

Deep Conversion of Carbon Monoxide to Hydrogen and Formation of Acetate by the Anaerobic Thermophile Carboxydothermus hydrogenoformans

OpenAIRE

Henstra, Anne M.; Stams, Alfons J. M.

2011-01-01

Carboxydothermus hydrogenoformans is a thermophilic strictly anaerobic bacterium that catalyses the water gas shift reaction, the conversion of carbon monoxide with water to molecular hydrogen and carbon dioxide. The thermodynamically favorable growth temperature, compared to existing industrial catalytic processes, makes this organism an interesting alternative for production of cheap hydrogen gas suitable to fuel CO-sensitive fuel cells in a future hydrogen economy, provided sufficiently lo...

Hydrogen production from catalytic decomposition of methane; Produccion de hidrogeno a partir de la descomposicion termica catalitica del biogas de digestion anaerobia

Energy Technology Data Exchange (ETDEWEB)

Belsue Echevarria, M.; Etxebeste Juarez, O.; Perez Gil, S.

2002-07-01

The need of substitution of part of the energy obtained from fossil fuels instead of energy from renewable sources, together with the minimal emissions of CO{sub ''} and CO that are expected with these technologies, make renewable sources a very attractive predecessor for the production of hydrogen. In this situation, a usable source for hydrogen production is the biogas achieved by means of technologies like the anaerobic digestion of different kinds of biomass (MSW, sewage sludge, stc.). In this article we suggest the Thermal Catalytic Decomposition of the methane contained in this biogas, after separation of pollutants like CO{sub ''}, H{sub 2}S. steam. This technology will give hydrogen, usable in fuel cells, and nanoestructured carbon as products. (Author) 7 refs.

HYDROGEN ENERGY: TERCEIRA ISLAND DEMONSTRATION FACILITY

Directory of Open Access Journals (Sweden)

MARIO ALVES

2008-07-01

Full Text Available The present paper gives a general perspective of the efforts going on at Terceira Island in Azores, Portugal, concerning the implementation of an Hydrogen Economy demonstration campus. The major motivation for such a geographical location choice was the abundance of renewable resources like wind, sea waves and geothermal enthalpy, which are of fundamental importance for the demonstration of renewable hydrogen economy sustainability. Three main campus will be implemented: one at Cume Hill, where the majority of renewable hydrogen production will take place using the wind as the primary energy source, a second one at Angra do Heroismo Industrial park, where a cogen electrical – heat power station will be installed, mainly to feed a Municipal Solid Waste processing plant and a third one, the Praia da Vitoria Hydrogenopolis, where several final consumer demonstrators will be installed both for public awareness and intensive study of economic sustainability and optimization. Some of these units are already under construction, particularly the renewable hydrogen generation facilities.

The safe operation zone of the spark ignition engine working with dual renewable supplemented fuels (hydrogen+ethyl alcohol)

Energy Technology Data Exchange (ETDEWEB)

Al-Baghdadi, Maher Abdul-Resul Sadiq [Babylon Univ., Dept. of Mechanical Engineering, Babylon (Iraq)

2001-04-01

The effect of the amount of hydrogen/ethyl alcohol addition on the performance and pollutant emission of a four-stroke spark ignition engine has been studied. The results of the study show that all engine performance parameters have been improved when operating the gasoline spark ignition engine with dual addition of hydrogen and ethyl alcohol. The important improvements of alcohol addition are to reduce the NOx emission while increasing the higher useful compression ratio and output power of hydrogen-supplemented engine. An equation has been derived from experimental data to specify the least quantity of ethyl alcohol blended with gasoline and satisfying constant NOx emission when hydrogen is added. A chart limiting the safe operation zone of the engine fueled with dual renewable supplemented fuel, (hydrogen and ethyl alcohol) has been produced. The safe zone provides lower NOx and CO emission, lower s.f.c. and higher brake power compared to an equivalent gasoline engine. When ethyl alcohol is increased over 30%, it causes unstable engine operation which can be related to the fact that the fuel is not vaporized, and this causes a reduction in both brake power and efficiency. (Author)

How carbon credits could drive the emergence of renewable energies

Energy Technology Data Exchange (ETDEWEB)

Mathews, John A. [Macquarie Graduate School of Management, Macquarie University, Sydney, NSW 2109 (Australia)

2008-10-15

The shift to renewable energy options and low-carbon technologies, in response to the concerns over energy security and climate change, is proceeding more slowly than many would like. The usual argument against rapid deployment of new technologies is the costs imposed on the economy, commonly interpreted in terms of upfront costs to be borne or involving large cash transfers to fund, for example, efforts to preserve rainforests. In this contribution I argue that such a perspective provides a continuing barrier to taking effective action, whereas a perspective based on creation and use of carbon credits provides a means of avoiding the shock of abrupt industrial change. Carbon credits granted for bona fide carbon load reductions could be created through private initiative, for example by merchant banks, to constitute a market that will complement regulatory-based initiatives such as national emissions trading systems. This is not a novel idea; indeed it is the way that capitalism has funded every major change, including the Industrial Revolution, through the creation of credit. The emergence of a global carbon credit economy is likely to precede a global regulatory system governing climate change and will doubtless help to stimulate the emergence of such a global system. (author)

How carbon credits could drive the emergence of renewable energies

International Nuclear Information System (INIS)

Mathews, John A.

2008-01-01

The shift to renewable energy options and low-carbon technologies, in response to the concerns over energy security and climate change, is proceeding more slowly than many would like. The usual argument against rapid deployment of new technologies is the costs imposed on the economy, commonly interpreted in terms of upfront costs to be borne or involving large cash transfers to fund, for example, efforts to preserve rainforests. In this contribution I argue that such a perspective provides a continuing barrier to taking effective action, whereas a perspective based on creation and use of carbon credits provides a means of avoiding the shock of abrupt industrial change. Carbon credits granted for bona fide carbon load reductions could be created through private initiative, for example by merchant banks, to constitute a market that will complement regulatory-based initiatives such as national emissions trading systems. This is not a novel idea; indeed it is the way that capitalism has funded every major change, including the Industrial Revolution, through the creation of credit. The emergence of a global carbon credit economy is likely to precede a global regulatory system governing climate change and will doubtless help to stimulate the emergence of such a global system