Animal rights campaigners were up in arms yesterday over reports that a German inventor was making diesel from dead cats.

Wolfgang Apel, president of the German Society for the Protection of Animals, told Reuters that using dead cats for fuel was outlawed in Germany.

"We're going to keep an eye on this case," he told the news agency.

However, Dr Christian Koch, 55, from Kleinhartmannsdorf says he doesn't use cats after all, rather spoiling things for punsters hoping to make jokes about putting a tiger in your tank. Any old biomatter will do: old tyres, paper, textiles, plastics weeds and so on.

The no-doubt aromatic mixture is heated to 300 C to extract the hydrocarbons, which are then fed through a catalytic converter (You see how terrible it is that he doesn't use cats?), to make biodiesel, Ananova reports. Koch has patented his process, and says that his biodiesel costs as little as 15 pence per litre to produce.

"I drive my normal diesel-powered car with this mixture," Bild quotes Koch as saying. "I have gone 170,000 km without a problem."

We checked this out with some qualified chemist-types who seemed to think the idea was plausible, whether or not it involved cats.

The underlying principle is fairly straightfoward: all organic material, animals and vegetables, contains fatty acids, albeit often in large involatile fat molecules. These can be broken down by heat into fatty acids and their derivatives which can in turn be converted into biodiesel.

One chemist told us that dead pets are routinely cremated anyway, because they are biohazardous material, although he acknowledged that beef lard or perhaps dead rats would be a more socially acceptable animal fuel source.

But turning the pets into fuel would reduce the atmospheric pollution from the cremation, he said, and converting them to fuel would at least make use of the energy released from the material. ®

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