Local and global environment issues, as well as the consumption and supply of energy, are major challenges for the future. A fuel cell is an ideal device to generate electricity from either fossil or renewable fuels as it is clean and efficient. By using fuel-cell propulsion running on hydrogen, the vehicle has (local) zero emission.
For a fuel cell with fuel-processing technology used for propulsion or auxiliary power units (APU), major air pollutants will be substantially reduced. Hydrogen fuel cells are therefore increasingly seen as a potential propulsion technology of the future for road transport. Additionally, fuel-cell APUs - possibly coupled with on-board fuel reformers - are also seen as a promising technology for both light- and heavy-duty vehicles.
However, despite the potential of these technologies to reduce the environmental impact of road transport and to improve energy efficiency, both technical and economic barriers need to be overcome for them to be successfully introduced into mass markets.
Issues to work on are the fuel-cell stack, components and main subsystems including the fuel processor and auxiliary components, the fuel-cell system and the vehicle integration, as well as the choice of fuel with its implications for technology and infrastructure.
The components and sub-systems are considered as major bottlenecks for fuel-cell-based vehicle systems. HyTRAN is therefore largely focused on the development of the necessary components and sub-systems to make them meet the actual requirements derived from the implementation of two fuel-cell systems.
The overall objectives of HyTRAN were to advance the fuel cell technology towards a commercially viable solution in terms of performance and cost.
HyTRAN aimed to advance the fuel cell technology by developing components and systems and to integrate the subsystem into two innovative fully integrated Fuel Cell Systems:
- Direct Hydrogen PEM Fuel Cell system, 80 kW power size, with innovative Stack and BoP;
- APU Diesel Reformate PEM Fuel Cell system 5 kW power size, including microstructured steam reformer, clean-up reactor, innovative stack and Balance of Plants.
The need for breakthroughs and innovations at the component level in order to meet the project objectives led to the following developments within HyTRAN:
- innovative 80 kW direct hydrogen stack with strong weight and volume reduction, increased efficiency, durability and start-up time, and with innovative MEAs (membrane electrode assembly);
- 5 kW reformate fuel-cell stack: work on innovative electro-catalyst and MEA elements, introducing novel catalysts and electrode structures;
- innovative humidification/dehumidification apparatus;
- heat exchanger and radiator customised for the application;
- micro-structured diesel steam reformer and gas purification units.
To validate the progress towards these objectives, two corresponding technical platforms (TP) were developed and used for assessment:
TP1 - Powertrain: development of a compact system for traction power by an 80 kW direct hydrogen PEM (Proton Exchange Membrane) fuel-cell system implemented in a passenger car;
TP2 - APU: development of a compact 5 kW auxiliary power unit for both light-duty and heavy-duty vehicles, including micro-structured diesel oil steam reformer, clean-up reactors, reformate hydrogen stack and balance of plant components.
In general, the first three years of the project were mainly devoted to the development of innovative components to widen the technology. The last two years then focused on the integration of these components into subsystems, including tests and preparation for implementation into vehicles.
During the first year, the main events for developing the hydrogen fuel-cell platform were stack design, characterising tests, air supply, water and thermal management studies. This work focused on the definition of the specification that could make the realisation of a scalable FC system possible, considering the required characteristics of efficiency and compactness. These activities later resulted in many key issues being identified and ‘frozen’. Major efforts have been focused on testing the stack on sensitivity, cycles and durability.
Continued activities have been devoted to developing the key components and providing a viable system design for the diesel-fuelled FC APU system. During the second year, progressive development of the fuel processor, which is a vital part of the APU system, has been made. Catalysts are now available for each stage of the reforming and CO clean-up system, and have been matched to the operating conditions identified from the system modelling activities. Prototype micro-channel plate reactors and fuel and water vaporisers have been designed, constructed and successfully tested.
The HYTRAN project developed a completely European 80 kW hydrogen fuel cell system and successfully installed it in an urban car. The fuel cell demonstrated relevant improvements in important areas such as power density, low temperature behaviour and durability, while the new vehicle's fuel efficiency is 15% better than the previous generation of the Fiat Panda Hydrogen Concept Car. The novel passenger vehicle has competed successfully in a number of 'green car' rallies. In May 2009 the HYTRAN car completed the 750 km EVS Viking Rally in 6 hours and 5 minutes, winning second place in the hydrogen vehicle category. However, on fuel efficiency it came first, consuming just 6.08 kg of fuel for the entire journey.