URBAN TRANSPORT PROJECT BY HYDROGEN TECHNOLOGIES FOR INTERNATIONAL EXHIBITION EXPOZARAGOZA 2008

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1 URBAN TRANSPORT PROJECT BY HYDROGEN TECHNOLOGIES FOR INTERNATIONAL EXHIBITION EXPOZARAGOZA 008 Montaner, P. IDOM Engineering Abstract This summer, 008, Zaragoza hosted an international Exhibition with the theme of Water and Sustainable Development. With this baseline EXPOAGUA, the managing company, decided to carry out an urban transport project with hydrogen technologies. The project began with the opening of the Exhibition in June 008, and it continues alive in the city today. The project, pioneered in Spain, developed a completely sustainable model. The vehicles selected for the project consume only hydrogen as energy for their engines and they generate only water steam as waste. The provision of hydrogen for these vehicles is done at a new hydrogen filling station with hydrogen generated on-site by electrolysis. Keywords: Hydrogen, Electrolyser, Fuel cell, Project management 1. Introduction This summer an International Exhibition was held in Zaragoza (Spain) with the theme of Water and Sustainable Development. In line with this marvellous philosophy, EXPOAGUA, the management company of the exhibition, invested firmly on developing a green urban transportation project with vehicles powered solely by hydrogen. The aim of the project was not only to be ready for the opening of the exhibition but also to continue this as a lifelong project in the city, as a reminder of the sustainability philosophy. This pioneering project is aimed at the future. Taking advantage of the success of an International Exposition, it aims to familiarize people with hydrogen technologies and to make them aware of the need to avoid using contaminant fuels, in an effort to reduce the harmful effects that contaminating fuels have on the environment. In the same way, the idea of transforming Zaragoza into a strategic point of the future Hydrogen Highway, with a hydrogen supply network for national transport as the European Community already foresees, is also important. The project was composed of two main areas. On the one hand to build a hydrogen supply infrastructure, and on the other to get a fleet of hydrogen vehicles, as various and versatile as possible, with no emissions. According to the idea of a completely sustainable project, all the electricity consumed by the exhibition facilities was obtained from renewable resources. For this purpose EXPOAGUA installed two wind farms and two solar gardens, where it generated the energy required for all of EXPO s needs, including the hydrogen station. Through this route, the circle of sustainability was closed, showing the technical viability and the possible establishment of this kind of technology. 55

2 Figure 1: Energetic circle of the project.. Hydrogen Filling Station Hidrogenera EXPO was the name we familiarly called the hydrogen filling station. This station, located in a new neighbourhood in the south of the city, was the first non-private installation of hydrogen, and the only one in operation in Spain during the summer of 008. Furthermore, it had the peculiarity of being able to produce its own hydrogen on-site, meaning that is was not necessary to take the fuel by road, as is the case with traditional filling stations for conventional vehicles. The operation of the hydrogen station can be split into several clearly differentiated phases. In the first phase, the production of hydrogen is carried out by a water electrolysis process. The system takes water from the city network and demineralises it with an inverse osmosis filter. The electrolyser takes this water and with the application of an electric current produces the disassociation of the water molecule into its two components, hydrogen and oxygen, according to the following chemical reactions: Catod ( ) : H OH + H O + e Anode 1 ( + ) : OH H O + O + e Figure : Diagram of alkaline electrolyser. 56

3 The alkaline electrolyser uses as an electrolyte, a dissolution of potassium (KOH), and is capable of producing a maximum of 1 normal cubic meters of hydrogen with a purity of over 99.5% with an outset pressure of 8 bar. The system is designed for continuous operation, so the maximum capacity of daily generation is close to 5 kg of hydrogen. The use of hydrogen in fuel cells requires a very high purity of gas, more than the hydrogen that is obtained directly from the electrolyser. This means that it is necessary to use a purifier unit, so that we can get a high purity of hydrogen (99,9995%) with a maximum waste of 5 ppm of oxygen. In case the hydrogen production is not enough to satisfy the demand or in case of maintenance or failure of the electrolyser, the station has the ability to get an external supply of hydrogen from 00 bar hydrogen platforms. The hydrogen produced in the electrolysis process is compressed by a two-phase membrane compressor, increasing the outset pressure from the electrolyser to the storage pressure designed at 40 bar.the compressor connects automatically when the pressure of the storage system decreases below the key point and it stops when the storage is full. The gas is stored in high pressure bottles with a total maximum capacity of storage at over 56kg of hydrogen. The supply to vehicles is done through a special hydrogen dispenser which is capable of refilling at two different storage pressures: 00 bar and 350 bar. This special condition exists because of the need to be able to refill the different kinds of vehicles that have been used during the International Exhibition. The whole system has been measured to supply hydrogen to a standard fleet of three to four buses, so that they can be refilled daily according to the operating schedules of the charge and discharge of storage bottles. 57

4 Electrolyser Back-up Storage Compressor Control Unit Figure 3: Diagram of components. Each one of the phases mentioned is carried out within a new facility which has the most up to date control systems and the most secure facilities ensuring correct operation. 3. Vehicle fleet With respect to vehicles, the project had two main goals. On the one hand, to take advantage of the Exhibition to combine a fleet of various kinds of hydrogen vehicles, as extensive and various as possible, showing their functionality and working at the same level as internal combustion engine vehicles. On the other hand, it aimed to keep a small fleet of these vehicles in operation in the city once the exhibition finished, using the new hydrogen station for refilling. The current reality of hydrogen vehicles is a little virtual. Though many possibilities can be found at an international level, few of them are available or developed enough. Most of the small number of vehicles on offer are simply prototypes or are in test phase, so there is no real possibility of purchasing one. The small number of options with any real possibility of being purchased, are very costly. So it is very difficult create a fleet with enough units for a new transport system. Working within this scenario our project chose to acquire some of the vehicles and to borrow or rent others from covenant firms with a view of returning them once the exposition finished. The project s own fleet included three minibuses with a capacity of people and range of over 00 km. They are small sized vehicles, less than 6 meters long, so they are very adapted to a 58

5 city centre or areas with restricted mobility. During the international Exposition they were doing special shuttle services inside EXPO for diplomatic staffs, but they will be used in city standard transport service now that the exposition has finished. Apart from these minibuses, there were also a number of other vehicles. The primary one used was a large capacity bus, capable of transporting more than 100 people and with range of over 400 km. There were several single-seater vehicles too, such as scooters and bicycles, also powered by hydrogen. Between them all, a distance of more than 19,000 km was covered in the three months of the exhibition. And they transported over 60,000 people. Photograph 1: EXPO hydrogen vehicle fleet. Although fuel cells are not the only technology available for use in hydrogen vehicles, all the vehicles in the EXPO project, were fed from fuel cells. The process for obtaining electricity from a fuel cell is the opposite to that used in the electrolysis process. In this process, hydrogen stored in tanks and the oxygen taken from the atmosphere are mixed to get a water molecule which generates an electric current that is used to feed the electric engines. This process, for a PEM fuel cell, follows the following chemical reactions: + ( + ) : H H + e Anode + Catode( + ) : H + 1 O H O With this technology, the only waste produced by the vehicles is the water steam of the chemical conversion. There is no other possible type of contamination. If we can obtain the hydrogen from water electrolysis with electricity from renewable sources, as we currently do, we are able to assure that the total process is completely free of any contaminant emissions. 4. Project challenges and conclusions The management of a project of these characteristics, with such a so innovative technical development, and with a very tight schedule, supposed a big challenge just only for the management of all the works and stakeholders. Some of the key challenges for the project were issues related to authorisation and licensing, as well as standards and regulations for these types of installations. In fact there are no specific directives in Spain for hydrogen stations, so it was necessary to work together with the Municipal and Regional Governments to agree the applicable regulations and security procedures to improve at the current installation. 59

6 The solution to this problem was to apply all the regulations referring to any facility related to the present installation, in all or in part, with specific consideration of the most restrictive conditions for each of them. Because of this, the hydrogen station complied with all the requirements in the main industrial regulations including the Fire Protection Rules, Chemical Products Storage Rules, Electrical Standards, and so on. The application of all these regulations made the station one of the most secure industrial installations. Another area that really created a big challenge was the project schedule. Though the project began some months before, the first important milestone of the project was the contracting of the supply and construction of the hydrogen station, which was signed on August 007. So, it was necessary to develop the main part of the project described above in less than one year. The authorisation projects were finished on November 007 and the building and activity licences were organised at the beginning of 008. The work of building and urbanizing the station was finalized in April in order to start the assembly of the hydrogen facilities. The testing phases were done by the first half of May, only one month before the opening of the Exhibition. As a conclusion of the project it is necessary to say that although it has been shown that hydrogen technologies are theoretically viable, the actual reality of hydrogen is not as advanced as that of currently operating technologies. It is obvious that the future establishment of hydrogen as a replacement for petroleum fuels should begin with the hard support of government and with all the initiatives that prompt these independent projects. References Bossel, U Does a Hydrogen Economy Make Sense?. Proceedings of the IEEE, Volume 94, Issue 10, Page(s): Gobierno de Aragón Plan Director del Hidrogeno en Aragón, Fuel Cells Handbook, 7th edition, Department of Energy, DOE, US. 004 Ochoa, J.R., 008 Normativa y Reglamentación de seguridad en materia de Hidrógeno Diploma de Especialización en Tecnologías de Hidrógeno, Univ. de Zaragoza. Ponencias, er Encuentro Sectorial del Hidrógeno y las Pilas de Combustible. Santiago de Compostela. Pool, R.; 005 Pump up the gas [hydrogen storage for transport applications]. Power Engineer. Volume 19, Issue 1, Page(s):18-1 T-Raissi, A.; Block, D.L.; 004. Hydrogen: automotive fuel of the future. Power and Energy Magazine, IEEE Volume, Issue 6, Page(s):40-45 Zabalza, I. Valero, A. Scarpellini, S., 005 Hidrógeno y Pilas de Combustible, Fundación para el Desarrollo de las Nuevas Tecnologías del Hidrógeno en Aragón Correspondence (for further information, please contact): Pedro Montaner Izcue. IDOM Phone: pmi@idom.com 60