Engineering news
Trials are progressing of an award-winning technology that could increase the practicality of hydrogen-powered cars.
Cella Energy, which is based at the Rutherford Appleton Laboratory on Harwell Science and Innovation Campus, Didcot, Oxfordshire, makes low-cost hydrogen storage materials using nanotechnology to encapsulate hydrogen at ambient temperatures and pressures.
This sidesteps the requirement for an expensive hydrogen infrastructure, the company said. Its innovation scooped an award from Shell last month.
Stephen Voller, chief executive, said the systems his company were developing circumvented some of the problems in using hydrogen as an automotive fuel, such as having to store it at very high pressures.
He said: “Because hydrogen occupies a very large volume, the pressures used in the hydrogen tanks in vehicles have to be very high – otherwise you’d end up with a trailer behind the average family car “Clearly this presents huge safety risks. It also presents a perception risk because most people look at one of these tanks and think it’s bomb-like. Third, it takes a great deal of energy to compress the gas to get it into the tank, so the energy balance is really not very good.”
Cella’s technology could see hydrogen stored in micro-beads transported to and from oil refineries by tankers. The fuel could then be used either as an additive to petrol to help reduce CO2 emissions in a standard tank or used in a fuel cell. “The aim is to be able to stand there with your regular pump and fill a vehicle in about three minutes with enough energy to drive 300 miles, and there’s no compressed gas or any of the safety concerns that you would have with that.” Vehicles would have to be modified to run purely on hydrogen but the first stage of tests had been focused on combining the hydrogen with petrol, Voller said. Adding the microbeads to petrol could result in a 30% reduction in CO2 emissions, he said. Obviating the need to compress the hydrogen would also make the energy balance used in storing, transporting and using the fuel better.
“At most oil refineries there are vast quantities of hydrogen available,” said Voller, “the trouble is moving it. If you go for high pressure tanks in vehicles, you’ve got to move high-pressure hydrogen from where it’s made at the refinery to the filling station, and then you’ve got to put it in your vehicle. All of those steps are clearly hazardous – and from an energy balance point of view make the benefits marginal. Frankly there’s a debate as to whether it might be cleaner just to use the petrol in the first place.”
Cella Energy is currently in discussion with a number of key automotive suppliers about its technology, Voller said.