Science - February 9, 2006

Hydrogen economy faces many hurdles

Hydrogen is a hot topic. President Bush has big plans for it; fellow Republican Arnold Schwarzenegger drives around in a hydrogen-powered car; and in Europe a lot of research is being conducted on the ‘new’ fuel. Last week the European research project Hyvolution, coordinated by Agrotechnology and Food Innovations, was launched in Wageningen.

President Bush wants a large proportion of American cars to be powered by hydrogen because the country is currently too dependent on oil from the Middle East. With his Freedom Car Initiative, he is setting aside 1.2 billion dollars for the necessary research.
Meanwhile, European scientists are also trying to find better ways to produce hydrogen. In the European research project, Hyvolution, with a budget of 9.5 million euros, Wageningen UR is working with institutes and universities in eleven other countries. The objective is to develop a blueprint for the production of sustainable hydrogen and to test it at an experimental plant.
‘It is important that the economy becomes sustainable, and hydrogen can play a part in this,’ says Professor Frons Stams, of the Laboratory of Microbiology and chair of the Platform Biologisch Waterstofvorming (platform for biological hydrogen formation). ‘Schwarzenegger already drives around in a hydrogen-powered car, and there are also experimental busses operating in Amsterdam that are powered by hydrogen from Shell. There is a need for hydrogen, and science can help. Hydrogen is definitely a clean fuel. And the energy that is released with the oxidation of hydrogen can be converted very efficiently into electricity.’

Inefficient
The first versions of fuel cells have already been developed in various countries. By converting hydrogen into electrical energy a car can be powered, for example. Many people do not know, however, that hydrogen is not a primary source of energy. It is not present in free form on earth, so it has to be made. For this purpose, fossil fuels are usually used, such as oil, coal and natural gas. The petrochemical industry has already been using hydrogen with the help of natural gas for a long time.
For their hydrogen-powered cars, Americans are so far planning to use hydrogen made with fossil fuels. Not really a sustainable development believe the Wageningen researchers. The Hyvolution project is therefore directed at the production of hydrogen using biomass such as waste products from the food industry, crop residues or crops cultivated specifically for making hydrogen.
Mr Rene Rozendal of the Environmental Technology department: ‘The advantage is that the process is CO2 neutral. Trees and plants take up CO2 and produce biomass, we harvest the biomass for the hydrogen and make CO2 as a by-product. The net result is that no extra CO2 is added to the atmosphere. The story is completely different with fossil fuels. When those are burned, CO2 that had been stored for millions of years in the ground is released into the atmosphere.’
But even if hydrogen is produced without the release of harmful emissions, there are still a lot of hurdles to overcome before its use can be optimalised, for example in cars. According to former professor of energy supply at TU Delft, Professor Rob Kouffeld, the question with the production of hydrogen is whether we are putting more energy into it than we are getting out of it. ‘I don’t think the hydrogen economy is around the corner, and certainly not with respect to cars. One problem is that the storage and transportation of hydrogen are very complicated. To power cars, trains and airplanes over long distances I think we will be seeing more synthetic hydrocarbon made from biomass in the future. For short distances by car I believe more in electrical power with batteries, or hybrid cars that have both an electric and a combustion motor.

Explosive
One disadvantage of hydrogen is that it can be dangerous. Kouffeld: ‘Hydrogen is very explosive. A small leak can have huge consequences.’ Professor Ekko van Ierland, of Environmental Economics and Natural Resources at Wageningen University, agrees that this is a problem and sees another one as well. ‘The energy content of hydrogen is in principle smaller than that of gas for example. So you would have to refill your tank frequently.’
The professor appreciates the fact that no harmful emissions are released with the use of hydrogen, but he is sceptical about its production out of biomass. ‘I think it would be better to use biomass directly in the production of electricity and to thereby reduce the use of fossil fuels. The extra step of making hydrogen is then no longer needed.’ If it were up to him, hydrogen would be produced from water using sustainable energy such as wind or solar power.
The Volkswagen Technology Center in the German town of Isenbüttel has opened a hydrogen fuelling station that produces liquid hydrogen with the help of solar panels. The solar panels supply electricity for electrolysis, the process by which water is split into hydrogen and oxygen. The plant produces twenty-five cubic metres of hydrogen per day. A car with a fuel cell can travel about two hundred kilometres on that amount; not a very large radius, which is why the production process still needs improvement.
In the Hyvolution project Dr Fons Stams and his colleagues will initially be looking at the possibility of creating small-scale plants for the production of hydrogen from biomass. The technology for making biodiesel from biomass already exists. But according to the researchers it would do no harm to bet on more than one horse when it comes to achieving a sustainable society.

Hugo Bouter

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