Monday, May 23, 2005

Hydrogen Superhighway Closer to Reality

Via GCC: Small car major ZAP (Zero Air Pollution), with a technology partner Apollo, has managed a technological (or engineering?) breakthrough that will allow fuel cell cars to carry ammonia instead of liquid or gasseous hydrogen as fuel.

To start a little from the beginning, fuel cell cars use hydrogen as fuel. Hydrogen though a very clean fuel (it's combustion produces water) is very volatile. So it has to be properly insulated because it can react with almost every constituent of air. Thus the technology to build an appropriate fuel storage capacity has been a key challenge for fuel cell cars. Strong (and expensive) tanks to store liquid hydrogen, and nanotechnology-based porous material to store hydrogen were some of the options that have been the most promising thus far. The new technology altogether bypasses the challenge.

The new car will store hydrogen in the form of ammonia(NH3), which will be passed through an onboard "ammonia cracker" that will pull out hydrogen from it and pass it to the Alkaline Fuel Cell (AFC). The technology offers several advantages over conventional PEM fuel cell vehicles.

Firstly savings in costs and logistics resulting from the elimination of hydrogen storage. Ammonia can be produced (to start with at least) at the same refineries where fossil fuels are produced, and can be transported in pretty much the same manner. Plus the actual vehicle becomes lighter and cheaper.

Secondly, AFC's are very efficient and not requiring expensive precious metal catalysts are cheaper than PEM's. They also operate well at room temperature and have a good cold start capability. ZAP-Apollo have solved a major technological problem related to CO2 poisoning that has prevented popularity of AFC cars thus far.

This could be a real breakthrough in achieving California governor Arnold Schwarzenegger's purported target of a Hydrogen Superhigway in California by 2010.