Hydrogen From Ammonia to Power Fuel Cell Cars

In their search for cheap methods to produce hydrogen to power fuel cell cars, British scientists proposed to derive the precious element from readily available ammonia.

The race for becoming the first car manufacturer to start selling fuel cell vehicles is more fierce than ever, with engineers and mechanics at Toyota, Honda, Hyundai and others working day and night on their prototypes. The aim of this is great- produce a vehicle that does not emit any toxic gases and does not rely on energy storage technologies that require hours to recharge.

However, as brilliant as this might sound, the process of producing hydrogen to power these zero-emission vehicles is far from environmentally friendly. Leaving aside the fact that producing hydrogen following the currently known methods is quite expensive, most commonly, the gas that is used to make commercially available hydrogen is supplied through fracking.

A team of British scientists, however, have proposed a way to produce hydrogen in safe, cheap and very eco-friendly manner. Martin Owen Jones and Bill David suggest that building on the idea, proposed by Arthur Titherley in the 1890s, to initiate a reaction that involves ammonia to produce the hydrogen, could finally make hydrogen fuel cells viable.

It probably will not come as a surprise to know that the process has indeed been already tested, but it has not been implemented widely due to costs. Although ammonia is the most widely available inorganic chemical around, in order to produce hydrogen from it, experts have used the very expensive and rare metal ruthenium as a catalyst, which not only costs a fortune, but also requires extremely high temperatures.

The scientists, however, believe that replacing ruthenium with sodium could drastically reduce the costs, especially since the products of the reaction, besides hydrogen, are nitrogen and the original, ready for reuse sodium.

But this is not all. In addition to lowering costs of materials, the ammonia-sodium method does not require extreme temperatures and heavy tanks for storage. In fact, it would only needs 400 degrees Celcius, which could be easily reached using the energy from a single car battery. What is more, storing ammonia on board of a vehicle is a lot more convenient than storing hydrogen alone, as the tanks that are needed are much lighter.

The team has not yet tested their method on a large scale, but they are convinced that there is nothing that could prevent the scaling up.

Image (c) STFC