October 21, 2014

Hydrogen fuel cells – the future?

Will new UK discovery make hydrogen the way forward?

Everyone agrees that we need to find an alternative to carbon-rich fossil fuels to power the next automotive generation and cut greenhouse gasses. But not everyone agrees on the most suitable alternative.

Electric power?

There has been huge investment in recent years the development of electric vehicles (EVs) by most of the major vehicle manufacturers. But, in the main, EVs are not the long term answer for mid-to-large size fleets.

However, EVs can serve their purpose in niche environments, albeit with a few considerations such as no need to travel very long distances.

Yet even in this capacity, there are still issues with the supporting infrastructure. Charging points can take weeks to fix in the event of a failure, as there are few supporting engineers, while the nearest EV dealers are often either out of range of the client site, or unwilling to collect.

New developments in hydrogen fuel cells

Many industry experts believe that vehicles powered by hydrogen fuel cells are the future – although there have been reservations in some quarters on safety and storage grounds.

Now, UK researchers have announced what they believe could be a game-changer in the use of hydrogen as the next mainstream fuel to power our future transport needs.

A new discovery by scientists at the Science and Technology Facilities Council (STFC) utilises ammonia as a clean and secure hydrogen-containing energy source to produce hydrogen on-demand in situ.

This exciting development potentially overcomes the problems associated with the use of hydrogen – mainly its safe storage and the huge costs of building a hydrogen refuelling infrastructure.

When the components of ammonia are separated, a technique known as cracking, they form one part nitrogen and three parts hydrogen. Many catalysts can effectively crack ammonia to release the hydrogen, but the best ones are very expensive precious metals.

However, the new method discovered by UK scientists involves two simultaneous chemical processes rather than using a catalyst, and can achieve the same result at a fraction of the cost.

Ammonia can be readily stored on-board vehicles at low pressures in conformable plastic tanks. Meanwhile, on the forecourts, the infrastructure technology for ammonia is as straightforward as that for liquid petroleum gas (LPG).

While few people think of ammonia as a fuel, the scientists at the STFC view it as the natural alternative to fossil fuels, and believe that it can be used in cars without the complications of a fuel-cell, which is the current thinking.

They say that a small amount of hydrogen mixed with ammonia is sufficient to provide combustion in a conventional car engine.  And they estimate that an ammonia’ decomposition reactor’ no bigger than a two-litre bottle could provide enough hydrogen to run a mid-range family car.

They have even thought about how they can make ammonia as safe as possible and stop the release of polluting nitrogen oxide gases. This fundamental scientific breakthrough, therefore, has the potential to radically change the use of hydrogen as a fuel.

The STFC scientists are currently in the process of creating a first, low-power static demonstrator system, a move which has prompted David Willetts, the UK Minister for Universities and Science, to call the discovery

“exactly the sort of innovation we need UK researchers and engineers to develop to put Britain at the forefront of solving modern day transportation problems.”

The use of ammonia in industry is nothing new and it is already one of the most widely transported bulk chemicals worldwide. It is the bedrock for the fertilisers that enable the production of almost half the world’s food.

The scientists say that increasing ammonia production is technologically straightforward, and there is no obvious reason why the existing infrastructure cannot be extended so that ammonia not only feeds but powers the planet.

Several car manufacturers, like General Motors, have already decided that hydrogen fuel cells are the future, and have begun to roll out a new generation of fuel-cell electric vehicles.

While batteries will continue to play a significant role in these cars, their range, which will be equivalent to conventional cars, will be provided by the hydrogen-powered fuel cell.

But as we have said, hydrogen presents is a major headache both on-board for the fuel cells, where it is stored in tanks at high pressure, and on the forecourt for refuelling, where it is stored at even higher pressures.

The STFC researchers say that safety issues of storing hydrogen on-board at these pressures are substantial, while the cost issues of installing a new high-pressure infrastructure across the nation are massively prohibitive.

The answer to both conundrums, they believe, might lie in a new discovery that involves a cheap and readily available material and a simple scientific process. Watch this space.