Heavy water as a valuable by-product of electrolytic hydrogen

A Combined Electrolysis Catalytic Exchange-Heavy Water Process (CECE-HWP) is being developed at Chalk River with the ultimate aim of producing by-product heavy water from electrolytic hydrogen streams although other earlier potential applications are also discussed. The gross heavy water dollar credit per GJ, based on the higher heating value of hydrogen, has been calculated as a function of the important variables: recovery, feed concentration, and price. Based on preliminary data and cost estimates, the net heavy water dollar credit has been estimated to be at least comparable to the by-product oxygen credit. The potential for by-product heavy water production from hydrogen in general, and from electrolytic hydrogen in particular, in Canada, the U.S.A., and the Western World is discussed in relation to Canada's present primary heavy water production capacity.     

Areca leaves as a source of carbon: Preliminary investigation as catalyst support for electrolytic hydrogen evolution in acidic medium

Our work tends to establish Green Energy from Waste concept. Refuses/wastes can be a secondary resource for variety of materials which may find applications in domestic, industrial, medical, electronic and energy devices. We have attempted to produce activated carbon powders from a cheap waste namely biomass of areca leaves. The material has been exploited as catalyst support materials in H₂ production through water electrolysis. Catalyst powders of 10% Ni and 1% Pt by weight were supported on the carbon produced from the leaves using NaBH₄ reduction of the respective salts. Physical features of the catalyst powders were evaluated through PXRD, FTIR, density, SEM, surface area. Catalytic activity of the biocarbon supported catalyst powders was assessed by LSV & CV. The carbon produced may attract technological importance because carbon source selected is cheap and green. Further the activated carbon may find applications such as electrode materials, adsorbent for color, odor and hazardous pollutants.     

Hydrogen sulfide as a source of hydrogen

We suggest that hydrogen sulfide (that which is removed from fossil fuels as an unwanted waste product, as well as that which might be sought as a mineral in its own right), should be considered as a source of hydrogen. We discuss several techniques by means of which hydrogen sulfide might be thus exploited. We address, very briefly, the apparent problem of finding materials of construction for use in such processes.     

The market potential for electrolytic hydrogen

By the year 2000, the potential market for advanced technology electrolytic hydrogen among specialty users is projected to be about half of what the merchant hydrogen market would be in the absence of electrolytic hydrogen. This potential market, representing an annual demand of about 16 billion SCF of hydrogen (approx. 200 MW of installed electrolyzer capacity), will develop from market penetrations of electrolyzers assumed to begin in the early 1980s.     

Intermetallics as cathode materials in the electrolytic hydrogen production

The intermetallics of transition metals have been investigated as cathode materials for the production of hydrogen by electrolysis from water–KOH solutions, in an attempt to increase the electrolytic process efficiency. We found that the best effect among all investigated cathodes (Hf₂Fe, Zr–Pt, Nb–Pd(I), Pd–Ta, Nb–Pd(II), Ti–Pt) exhibits the Hf₂Fe phase. These materials were compared with conventional cathodes (Fe and Ni), often used in the alkaline electrolysis. A significant upgrade of the electrolytic efficiency using intermetallics, either in pure KOH electrolyte or in combination with ionic activators added in situ, was achieved.The effects of these cathode materials on the process efficiency were discussed in the context of transition metal features that issue from their electronic configuration.     

Municipal water supply dams as a source of small hydropower in Turkey

In Turkey the laws published in recent years succeeded in promoting the utilization of renewable energy for electricity generation. After the publication of Renewable Energy Law on 18 May 2005 in Turkey there occurred a boost in renewable energy projects along with hydropower development. Thus, the economically feasible hydropower potential of Turkey increased 15% and the construction of hydropower plants also increased by a factor of four in 2007 as compared to 2006. From this perspective, this paper was aimed to evaluate the small hydropower potential of municipal water supply dams of Turkey and discussed the current situation of SHP plants in terms of the government policy. It is estimated that the installing small hydropower plants to exiting 45 municipal water supply dams in Turkey will generate 173 GWh/year electric energy without effecting the natural environment. For a case study, Zonguldak Ulutan Dam and its water treatment plant has been investigated in detail.     

Mobile electrolytic hydrogen generators

A small mobile electrolytic hydrogen generator was developed and built in order to provide hydrogen gas for the filling of meteorological balloons in the field and at temporary and remote weather stations. The capacity of the unit is 2 standard m³/h (H₂) and utilizes 25 cells with an electrode area of 0.10 m² each. The hydrogen gas is compressed to fill steel cylinders at 17 MPa gauge. Electrical power for the plant is supplied from a separate generating set on its own trailer. The trailer with plant has a mass of 4.25 tonne on a deck area of 3.92 × 1.64 m².     

Baseline model of a centralized pv electrolytic hydrogen system

This study performs an economic and environmental analysis of a centralized pv electrolytic hydrogen system scaled to supply H₂ to one million light duty vehicles and light commercial trucks. Annual H₂ production is 217-million kg. The size of the pv electrolysis plant to produce this quantity of H₂ is a 5.12-GW_dc-in electrolysis plant and a 6.0-GW_p pv power plant. The land area of the pv electrolysis plant is 260 km². The total capital costs of the pv electrolysis H₂ system is $12.4 billion. The levelized H₂ pump price estimate is $6.48/kg. The life cycle primary energy use is 36 MJ/kg of H₂ consumption, and life cycle CO₂ equivalent emissions are 2.6 kg/kg of H₂ consumption. The replacement of conventional gasoline powered vehicles with H₂ powered vehicles reduces primary energy use and CO₂ emissions by 90%.     

Nuclear energy as a primary energy source for hydrogen production

New forms of energy are required to solve the future problems of the world energy market, especially as regards the substitution of mineral oil. High-temperature reactors can make an important contribution towards this goal. The prerequisite is a temperature availability of approx. 950°C, which has been demonstrated in the AVR reactor at Jülich for 3 years. The 300-MW THTR is being constructed as a continuation of the German HTR programme. At present some processes for coal modification are being promoted by the Development Programme of the Federal Republic of Germany (FRG). The most ideal application of the high-temperature reactor could be the production of hydrogen from water with the aid of thermochemical methods and hybrid processes.     

Carbon nanotubes/aluminum composite as a hydrogen source for PEMFC

Al matrix composites reinforced with 0–5 vol. % carbon nanotubes (CNTs) were fabricated by spark plasma sintering (SPS) to examine their hydrogen generation properties from the hydrolysis of Al in 10 wt. % NaOH solution at room temperature. The 5 vol. % CNTs/Al composite exhibits a maximum hydrogen generation rate of 120 ml/min g, which is about 6 times higher than that of Al without CNTs due to the synergetic effects of the porous Al matrix, which has a large reaction area and galvanic corrosion between the Al matrix and the CNTs. The hydrogen gas generated from the hydrolysis of the CNTs/Al composite has high purity without any production of undesirable CO. PEMFC produced electricity at 10 A and 0.73 V for 13 min, with hydrogen generated from the hydrolysis of 3.5 g–5 vol. % CNTs/Al composite. The CNTs/Al composite was effectively used as a hydrogen source for PEMFC.     

Renewable electrolytic hydrogen potential in Algeria

The present paper deals with the assessment of the renewable hydrogen production potential in Algeria. The studied system produces hydrogen by electrolysis of water; electricity is supplied by a photovoltaic generator. Adequate mathematical models were used to calculate the electrolytic hydrogen production. Detailed hourly simulations were used to assess the potential for the entire country and to draw it maps. Throughout this study, the influence of the tilt angle of a photovoltaic generator has been investigated. It has been observed that the tilt angle has an impact on solar energy received by the photovoltaic generator, the produced solar electrical power and the rate of hydrogen production. We have calculated the optimal angles to maximize each element. We were particularly interested in the optimal angle to maximize hydrogen production. We found that the solar hydrogen potential for Algeria varies from 0.10 Nm³/m²/d to 0.14 Nm³/m²/d. This potential is quite significant, especially in the arid region of southeastern Algeria. The lowest potential is located in the northeast region. For stand-alone systems, it is important to assess the minimum available level, as their sizing takes into account the most unfavorable case. This level is between 0.07 Nm³/m²/d and 0.13 Nm³/m²/d. This shows that, even for a stand-alone system, the potential is quite high. Finally, we provide robust correlations that allow calculating the potential and the angle of inclination maximizing it for the whole of Algeria.     

Recent development of large electrolytic hydrogen generators

An overview of the history and market of large electrolysis units is presented. The historical background introduces and explains the thought process behind a new design of Teledyne's Electra Cell alkaline electrolysis hydrogen generators.The new design enables construction of modules capable of 1.6 ton per day of hydrogen. The cost of hydrogen is used as a criterion for the selection of optimum performing cells as a function of user parameters. It is suggested that due to cell costs, the highest efficiency cell does not always produce the cheapest hydrogen.     

Biogas as hydrogen source for fuel cell applications

In the last decade, production of biogas from biomass degradation has attracted the attention of several research groups. The interest on this hydrogen source is focused on the potential use of this gas as raw material to supply high temperature fuel cells (HTFC). This paper reports a wide research investigation carried out at CNR-ITAE on biogas reforming processes (steam reforming, autothermal reforming and partial oxidation). A mathematical model was developed, in Aspen Plus, and an experimental validation was made in order to confirm model results. Simulations were performed to determine the reformed gas composition and the system energy balance as a function of process temperature and pressure. The value of Gas Hour Space Velocity (GHSV) was selected for calculating compositions at full equilibrium, as it is expected in operative large scale plant. To obtain a realistic evaluation of the reforming processes efficiency, the energy balance for each examined process was developed as available energy of outlet syngas on inlet required energy ratio. The comparison between values of efficiency process gives useful indication about their reliability to be integrate with fuel cell systems.     

Electrodeposition of self-supported transition metal phosphides nanosheets as efficient hydrazine-assisted electrolytic hydrogen production catalyst

The synthesis of electrocatalysts which used simultaneously as electrodes for the hydrazine oxidation reaction (HzOR), and hydrogen evolution reaction (HER) can significantly improve the efficiency of hydrogen production in the water splitting process. Here, Ni–Co–Fe–P binder-free nanosheets were fabricated using the electrochemical deposition method and used as an effective, stable, and cost-effective electrode for hydrazine-assisted electrochemical hydrogen production. Taking advantage of high surface area, being binder-free, and synergistic effect between the elements in the electrode composition, this electrode showed unique electrocatalytic activity and stability. When this electrode was used as a bifunctional electrode for HzOR-HER, a cell voltage of 94 mV was required to reach a current density of 10 mA cm^?2. The results of this study indicated that the Ni–Co–Fe–P electrode is an excellent candidate for the hydrogen production industry.     

Improved cathodes for industrial electrolytic hydrogen production

Reduced overpotentials for the generation of hydrogen by alkaline water electrolysis can be achieved with a.c. activation of porous Ni electrodes. Reductions of 50–60 mV were attained which would contribute towards reducing costs in commercial pure hydrogen production by electrolysis.     

Polysilanes: The grail for a highly-neglected hydrogen storage source

The hydrogen economy is a proposed system of delivering energy using hydrogen for engines and fuel cells. Otherwise, hydrogen, in comparison to hydrocarbons, is quite difficult to store or transport with current technology since it possesses a good energy density by weight, but a poor energy density by volume requiring a large tank to store at high pressure and low temperature. In this context, polysilanes constitute a neglected hydrogen storage source. We present a general catalyzed environmentally friendly, rapid and safe hydrogen production from organosilane hydrogen carriers' derivatives by reacting with water. The reaction is successful with a wide range of silane derivatives in quantitative yield of H₂ gas and could be used for daily life applications due to its modest cost, easy approach for implementing and limitation of greenhouse gas liberation.     

The economics of hydrogen as a fuel

Second Law costs together with an accounting for the cost of environmental or health hazards constitute Real Costs, i.e. costs seen from the viewpoint of the majority. Time at which the costs of various competing fuels have to be compared is the time at which they will have to be used. This is not that at which they will be competitive compared with the exhausting fuels, but some years (perhaps as much as two decades) earlier.The First Law costs of H₂ from coal are $4.00/MBTU. No other methods compete at this time. Biomass is likely to do so if developed. Photo-oriented methods might do so.Second Law costs are little known and need research. For automotive transportation, H₂ is around 1.5 times more efficient in burning than gasoline. Pollution costs would be 13–30% of the costs of a fuel from coal. H₂ gas storage in cars would add around 30% to these costs.Synthetic gasoline could not be made after 2010 for greenhouse effect reasons. But H₂ could be made from coal until 2040, if CO₂ is rejected seaward. This would have an important effect on amortization considerations. The real costs of H₂ from coal will be around 1/3 the costs of synthetic gasoline from coal.Among the newer concepts for H₂ is radiation of H₂O with direct concentrated solar light.     

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

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 CO₂ and CH₄ 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 energy of the millennium) through gasification reaction in supercritical water, as a source of renewable energy to policy-makers. Oil palm topped the ranking as number 1 fruit crops in terms of production for the year 2007 with 36.90 million tonnes produced or 35.90% of the total edible oil in the world. Its potentiality is further enhanced by the fact that oil constitutes only about 10% of the palm production, while the rest 90% is biomass. With a world oil palm biomass production annually of about 184.6 million tons, the maximum theoretical yield of hydrogen potentially produced by oil palm biomass via this method is 2.16×10¹⁰ kg H₂ year⁻¹ with an energy content of 2.59 EJ year⁻¹, meeting almost 50% of the current worldwide hydrogen demand.