Next step taken in fuel cell development

AFC Energy claims that field tests of its alkaline-based hydrogen fuel cell technology at a chlor-alkai plant in Germany have proved that it can generate and export electricity to a grid as efficiently as traditional higher-cost platinum-based electrodes.

The success of the test, which took place at Akzo Nobel’s Bitterfeld site, moves the UK-based company a step closer towards its full-scale production goals. It has also almost completed the upgrade to its development facility, which will enable it to manufacture up to 1,000 of the electrodes used in its fuel cells per day.

Ian Balchin, AFC Energy’s managing director, said: “This successful testing of our fuel cell system using proprietary, lower-cost electrodes, demonstrates that AFC Energy has taken the next step in the development of a truly low-cost, commercially viable alkali fuel cell system.”

The fuel cell is based on an electrolyte called Potassium Hydroxide (KOH), which enables Hydroxil-ions to move around relatively freely, while cooling the fuel cell at the same time. The solid polymer electrodes employed in traditional Polymer Electrolyte Membrane (PEM) fuel cells do not enable such activity, however, which results in higher resistance and a less efficient transfer of transient matter from anode to cathode, AFC claims.

The KOH electrolyte also absorbs the water produced by splitting H2 atoms, but AFC strongly denies that the carbon dioxide absorbed at the same time leads to CO2 poisoning, a process that causes irreversible destruction. Instead, the accumulated CO2 in the electrolyte can be removed by simply changing the liquid.

The same is not true of PEM fuel cells, however, which are permanently damaged by CO2 poisoning and, therefore, need to be replaced more often, AFC attests.

As to target markets, the company plans to sell its fuel cells into the chlor-alkali industry for use in stationary power generation. The system employs plants’ surplus hydrogen, which is generated as a by-product. The waste-to-energy market, where hydrogen can be liberated from organic waste, is also seen as another possibility.

But AFC is also in the process of developing a 50kW system for large-scale multi-megawatt installations, which is expected to be ready for field trials in the first quarter of 2011. Fuel cell scientist Dr Richard Dawson, former senior engineer at Ceres Power, has just joined the firm to help accelerate such development.