Hydrogen as a fuel in the transport sector in Algeria

A number of issues related more particularly to green gases emissions and fuel availability has resulted worldwide from the transport sector expansion. Stringent regulation laws, improvement in engine efficiency and alternative fuel options have been proposed to address these issues. However, the suitability of an alternative fuel depends on its performance, cost and availability. By its versatility in use and its renewability, hydrogen, as an alternative fuel, offers the best potential for reducing greenhouse gases emission, improving engine efficiency and ensuring fuel security.     

Hydrogen: automotive fuel of the future

This work presents a perspective on the production and use of hydrogen as an automotive fuel. Hydrogen has been hailed as the key to a clean energy future primarily because it can be produced from a variety of energy sources, it satisfies all energy needs, it is the least polluting, and it is the perfect carrier for solar energy in that it affords solar energy a storage medium. Efforts are underway to transform the global transportation energy economy from one dependent on oil to that based on sustainable hydrogen. The rationale behind these efforts is that hydrocarbon-based automobiles are a significant source of air pollution, while hydrogen-powered fuel cell vehicles produce effectively zero emissions. Besides the transportation area, fuel cells can also reduce emissions in other applications such as the residential or commercial distributed electricity generation. Hydrogen is the perfect partner for electricity, and together they create an integrated energy system based on distributed power generation and use. A discussion on the sources of hydrogen in the near- and long-term future as well as the cost of hydrogen production is provided.     

Hydrogen as a fuel

Hydrogen, used as fuel, has a number of attractive features that make it a leading candidate in the search for an alternative to the dwindling and progressively less reliable supply of fluid hydrocarbon fuels. Hydrogen produced by electrolysis using hydro- or nuclear-generated electricity will be available in Canada at prices competitive with other portable forms of energy before the end of the century. This paper examines the use of carbon-free electrolytic hydrogen as a motor vehicle fuel and as a fuel for fuel cells. A review of onboard hydrogen storage systems indicates that the propulsion power unit of hydrogen-fueled vehicles must be considerably more efficient than present gasoline-fueled internal combustion engines in order to compensate for the larger size and greater weight of hydrogen storage systems. Hydrogen-fueled internal combustion engines are more efficient than similar gasoline-fueled engines, but the improvement is not sufficient to offset the storage system limitation. Fuel cells operate with much higher efficiency than internal combustion engines, especially at partial loads. A comparison between H₃PO₄ and KOH fuel cells show that where carbon-free hydrogen is available from the onboard storage system, the KOH fuel cell offers the higher level of performance.     

Hydrogen and fuel cells: Towards a sustainable energy future

A major challenge—some would argue, the major challenge facing our planet today—relates to the problem of anthropogenic-driven climate change and its inextricable link to our global society's present and future energy needs [King, D.A., 2004. Environment—climate change science: adapt, mitigate, or ignore? Science 303, 176–177]. Hydrogen and fuel cells are now widely regarded as one of the key energy solutions for the 21st century. These technologies will contribute significantly to a reduction in environmental impact, enhanced energy security (and diversity) and creation of new energy industries. Hydrogen and fuel cells can be utilised in transportation, distributed heat and power generation, and energy storage systems. However, the transition from a carbon-based (fossil fuel) energy system to a hydrogen-based economy involves significant scientific, technological and socioeconomic barriers to the implementation of hydrogen and fuel cells as clean energy technologies of the future. This paper aims to capture, in brief, the current status, key scientific and technical challenges and projection of hydrogen and fuel cells within a sustainable energy vision of the future. We offer no comments here on energy policy and strategy. Rather, we identify challenges facing hydrogen and fuel cell technologies that must be overcome before these technologies can make a significant contribution to cleaner and more efficient energy production processes.     

Electrochemistry of fuel cells for transportation applications

Fuel cells are promising power sources for electric vehicles and do not suffer from the inherent limitations of efficiency, energy density, and lifetime, as encountered with all types of batteries considered for this application. The projected performance of fuel-cell vehicles is comparable to that of the internal combustion and diesel engine vehicles but with the additional advantages of higher fuel efficiency, particularly with synfuels from coal. The ideal fuel for a fuel-cell power plant for electric vehicles is methanol. This fuel is reformed to hydrogen, which combines with oxygen from the air in an acid electrolyte (phosphoric, solid polymer, or superacid) fuel cell to produce electricity. Though the phosphoric acid fuel cell is in the most advanced state of development (mainly for power generation applications), the solid polymer and superacid electrolyte fuel cells are more promising for the transportation application because of the faster oxygen reduction kinetics (and hence potential for higher power densities) and shorter start-up times. Alkaline electrolyte fuel cells can be used only with pure hydrogen (which causes a weight or energy penalty for any of the methods it can be carried on board the vehicle), but have the best potential for minimizing or eliminating noble metal requirements. The paper summarizes needed areas of research (i.e. reduction or elimination of noble metal loading, finding CO-tolerant electrocatalysts, finding less expensive solid polymer electrolytes, synthesis and elucidation of higher molecular weight superacids) to advance fuel-cell technology for vehicular applications.     

Sodium borohydride as a fuel for the future

In a time of unprecedented change in environmental, geopolitical and socio-economic world affairs, the search for new energy materials has become a topic of great relevance. Sodium borohydride, NaBH₄, seems to be a promising fuel in the context of the future hydrogen economy. NaBH₄ belongs to a class of materials with the highest gravimetric hydrogen densities, which has been discovered in the 1940s by Schlesinger and Brown. In the present paper, the most relevant issues concerning the use of NaBH₄ are examined. Its basic properties are summarised and its synthesis methods are described. The general processes of NaBH₄ oxidation, hydrolysis, and monitoring are reviewed. A comprehensive bibliometric analysis of the NaBH₄ publications in the energy field opens the discussion for current perspectives and future outlook of NaBH₄ as an efficient energy/hydrogen carrier. Despite the observed exponential increase in the research on NaBH₄ it is clear that further efforts are still necessary for achieving significant overchanges.     

Hydrogen from aluminium in a flow reactor for fuel cell applications

Aluminium appears to be a promising material for on-board hydrogen generation in fuel cell applications given the comparatively large amount of hydrogen produced per gram of aluminium in a safe system. A microfuel processor with aluminium and water as reactants is developed in a flow reactor for application in portable power sources. Two types of reactor are used. One reactor permits the direct feeding of liquid water in channels containing aluminium pellets, whereas the other utilizes the heat produced from the reaction to vapourize liquid water before entry into the reactor. Two additives, namely, calcium oxide (CaO) and sodium hydroxide (NaOH), are used to enhance the reaction rate. A maximum conversion of 78.6% with respect to aluminium is achieved when the water entering in the reactor is vapourized partially. In the case of liquid water entering the reactor, the conversion is 74.4%.     

Exergy analysis of a fuel cell power system for transportation applications

An exergy analysis of a solid polymer fuel cell power system for transportation applications is reported. The analysis was completed by implementing the fundamental governing second law equations derived for the system into a fuel cell performance model developed previously. The model analyzes all components of the system including the fuel cell stack and the air compression, hydrogen supply, and cooling subsystems. From the analysis, it was determined that the largest destruction of exergy within the system occurs inside the fuel cell stack. Other important sources of exergy destruction include irreversibilities within the hydrogen ejector and the air compressor, and the exergy associated with the heat rejected from the radiator. The results may aid efforts to optimize fuel cell systems.     

Hydrogen as fuel: a critical technology?

The potential of hydrogen energy technologies for being recognized as critical technologies (CTs) in the context of sustainable development is briefly discussed in view of the assessment approach and definitions accepted pertaining to CTs by the institutions dedicated to science and technology policy development.The concepts of sustainable development, the relationship between the level of national income and the extent of energy utilisation, CTs in general and national CTs (NCTs) are considered for different types of countries at different stages of economic development.Views of industry and business sectors on CTs and the roles of governments and universities are emphasized. The influence of public acceptance of hydrogen as a fuel is included.It is concluded that in addition to its exceptionally constructive environmental impact at the local, regional and global levels: hydrogen is expected to bring about a substantial change in the present state of affairs by creating a large number of new and diverse technologies, vast employment opportunities in all sectors and by delivering highly efficient and decentralized energy utilisation, free of geopolitical dependence in most cases. In this regard, though hydrogen is considered as a possibility presently, in the near future hydrogen energy technologies will inevitably be recognised as CTs for countries that are consciously adjusting for sustainable development.     

Pem fuel cells for transportation and stationary power generation applications

We describe recent activities at Los Alamos National Laboratory devoted to polymer electrolyte fuel cells in the contexts of stationary power generation and transportation applications. A low cost/high performance hydrogen or reformate/air stack technology is being developed based on ultra-low platinum loadings and non-machined, inexpensive elements for flow-fields and bipolar plates. On-board methanol reforming is compared to the option of direct methanol fuel cells in light of recent significant power density increases demonstrated in the latter.     

Modelling and analysis of a solid polymer fuel cell system for transportation applications

This paper presents the development and application of a performance model for a solid polymer fuel cell power system for transportation applications. The model simulates the operation of all the components in the system — including the fuel cell stack, and the air compression, hydrogen supply, and cooling subsystems. Two duty cycles are used to examine the performance of the baseline system, as well as to evaluate the benefits obtained by improving individual system components. The results indicate that the largest improvements in system performance would be obtained by (a) a reduction of the cooling loads, (b) improving the efficiency of the inlet air compressor, and (c) recovery of the thermomechanical energy in the stored compressed hydrogen.     

Hydrogen fuel as an important element of the energy storage needs for future smart cities

A considerable amount of non-dispatchable photovoltaic and wind power have always been planned in smart cities, however, the problem of massive energy storage has not yet been solved which limits the use of green energy on larger scale. At present the only battery energy storage is available, and it is effective only for storing modest quantities of energy for short periods of time. The other storage technology options are not often commercially available items; rather, they are just good concepts that need to be tested for viability. Currently, the only alternative options for turning an urban development into one that exclusively uses green energy is to use that energy to generate hydrogen through electrolyzers, then use this fuel to generate the required electricity in order to stabilize the grid. Even more appealing is the idea of using wind and photovoltaic energy to transform smart communities into a centre for producing hydrogen in addition to a city that solely uses renewable energy. The most likely solution, absent an urgent debate inside the science establishment, will be to import electricity from the burning of hydrocarbons while continuing to pay carbon offsets, which is incompatible with the goal of using only renewables. The smart city has not officially accepted this issue, just like the science establishment.     

The prospects for hard coal as a fuel for the Polish power sector

This paper presents the prospects for the development of the Polish hard coal sector from the perspective of the power sector. The most important issues determining the mid- and long-term future for domestic coal production are: (1) the development of the economy, hence the demand for electricity, (2) regulations (mostly environmental) affecting the power sector, (3) the competitiveness of coal-based technologies, and (4) the costs of domestic coal production. Since the range of issues and relations being considered is very broad, a specific method needs to be employed for the quantitative analysis. The tool applied in this study is the partial equilibrium model POWER-POL, in which both the coal and the power sectors are incorporated. The model focuses on energy–economy–environmental issues without capturing detailed macroeconomic links. The model was run under six scenario assumptions. The results show that the domestic coal sector should maintain its position as a key supplier of primary energy for the Polish power sector. However, the environmental regulations to which the domestic power sector has to conform will decrease the share of coal in the fuel-mix. Since the investment processes in this sector are usually long-term, the effects of changes will be noticeable from 2015 onwards.     

Hydrogen as a spark ignition engine fuel

Review is made of the positive features and the current limitations associated with the use of hydrogen as a spark ignition engine fuel. It is shown that hydrogen has excellent prospects to achieve very satisfactory performance in engine applications that may be superior in many aspects to those with conventional fuels. A number of design and operational changes needed to effect the full potential of hydrogen as an engine fuel is outlined. The question whether hydrogen can be manufactured abundantly and economically will remain the limiting factor to its widespread use as an S.I. engine fuel in the future.     

Hydrogen as an activating fuel for a tidal power plant

Ocean tides, as an environmentally clean and inexhaustible natural source of energy, can be used as one alternative for replacing fossil fuels. But because the tides are dependent on the moon phases, which do not always coincide with the time of human activity, tidal projects usually require a special system for the accumulation of energy for off-peak periods. The production of hydrogen by electrolysis can be considered one such system. This paper outlines the method by which hydrogen produced during off-peak tidal power plant operation can be used as an activating fuel to furnish the same plant during the peak-load demands.With our approach (see [1]) the energy of the tide is converted into the energy of compressed air by means of specialized chambers which are put on the ocean bed. Ocean water from the dammed region passes through the chamber where it works as a natural piston compressing air in the upper part of the closure. For the peak periods the compressed air can be heated by combustion of the stored hydrogen, and expanded through high-speed gas turbine generators. For the off-peak periods, the energy of non-heated compressed air is used for the production of the hydrogen fuel. In this case the total electric output of the power plant would be decreased somewhat because the losses of the energy would be taken for the production of the hydrogen fuel.     

Hydrogen as a transportation fuel produced from thermal gasification of municipal solid waste: an examination of two integrated technologies

Innovative technologies are required to offset increasing consumption and declining stocks of non-renewable resources. This study examines a possible enhancement of waste management and transportation by integrating two emerging technologies: municipal solid waste (MSW) gasification and fuel cell vehicles (FCVs), by fueling FCVs with hydrogen produced from gasified MSW. Material and energy flows were modeled in four MSW management scenarios (incineration, landfill, gasification, gasification with recycling) and four transportation scenarios (hybrid gasoline-electric, methanol FCVs, hydrogen FCVs using hydrogen from natural gas or municipal solid waste). Technological performance deemed feasible within 2010–2020 was assumed. Greenhouse gas emissions and non-renewable energy use were used to assess overall system performance. Gasification with hydrogen production performs as efficiently as incineration, but is advantageous compared to landfilling. Taking into account additional environmental criteria, the model suggests that hydrogen from MSW gasification for FCVs may provide benefits over conventional MSW treatment and transportation systems.     

The role of renewable fuel supply in the transport sector in a future decarbonized energy system

Battery electric vehicles (BEVs) and fuel cell electric vehicles (FCEVs) have been identified as two electromobility options which can help to achieve GHG emission reduction targets in the transport sector. However, both options will also impact the future energy system characterized by integration of various demand sectors and increasing intermittent power generation. The objective of this paper is to examine the optimal mix of both propulsion systems and to analyze the cost for renewable fuel supply. We propose a generic approach for dimensioning of fast charging and hydrogen refueling stations and optimization of the fuel supply system. The model is applied in a case study for passenger cars on German highways. The results indicate that a parallel build-up of stations for both technologies does not increase the overall costs. Moreover, the technology combination is also an optimal solution from the system perspective due to synergetic use of hydrogen but limited efficiency losses. Hence, BEVs and FCEVs should jointly contribute to the decarbonization of the future energy system.     

Status of solid polymer electrolyte fuel cell technology and potential for transportation applications

The solid polymer electrolyte fuel cell technology was used to provide electrical power for two operational spacecraft programs, and development programs span a wide range of applications which include ground power and undersea, as well as advanced space systems. The technology is also finding applications in the areas of water electrolysis and chlor-alkali production. During 1981 a study was conducted for the Los Alamos National Laboratory to determine the feasibility of using this technology for vehicular propulsion. The results of the study show that, with adequate development, such a power plant is possible which will meet the performance, size and weight objectives. It is also estimated that the costs for such a system could be competitive with other potential advanced power systems.