The result will produce electricity from liquid petroleum gas (LPG) - Calor or Camping gas.

Last year Voller bought Kat-Chem, a German firm with ‘reformer’ technology which converts LPG - butane and propane - to the hydrogen required by most fuel cells.

Since then, Voller has been working to refine the reformer. “The biggest challenge is getting rid of contaminants in the reformer output,” CEO Steve Voller told EW. “Fuel cell membranes are very sensitive to some of the contaminants such as carbon monoxide and sulphur.”

Reformers of the Kat-Chem type mix steam at 800°C with LPG in a catalyst to produce H2 and CO2, both of which can be pumped straight into the fuel cell, the H2 being consumed and the CO2 passing straight through.

However, some CO is formed, and sulphur compounds added to give gas its characteristic smell become pollutants. “The trick is getting rid of them. It’s complicated chemistry,” said Voller. “We are getting levels down to under 10ppm residue which makes very little difference to the life of the membrane.”

The scrubbing cocktail will need replacing less than once a year, Voller estimates. Once the reformer gets to temperature, the exothermic nature of the reaction keeps it there, but this takes around half an hour. In the mean time, integrated batteries will supply the load and the heaters. “We ended up producing a very sophisticated controller that manages the system,” said Voller. “That has taken a lot of time.” The controller also manages waste water and heat.

Initially aimed as an auxiliary power unit for boats, Voller claims its 1kW LPG-powered electrical power source will be half the size and weight of conventional marine generators - although not as powerful - but as quiet as a desk top PC. “Conventional generators are big and heavy because they have to have lots of sound proofing and anti-vibration mounts,” said Voller.

The firm intends to make 1kW LPG fuel cells commercially available by the end of 2007.