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Sulphurous Bugs

Hungry microbes may provide the answer to the high sulphur content of some coals, if the success of a research project at the University of Canterbury is any indication.

The bacteria are able to remove 98% of the inorganic sulphur from coal samples. The organic sulphur content is harder to get at, says Dr Ian Gilmore, as it is more tightly bound chemically. The microbes are a "cocktail mixture" of naturally-occurring bacteria found in local mines. Dr Gilmore hopes to identify a strain that will feed on the organic sulphur.

The research, carried out by postgraduate student Harijanto Seotjijo, is unusual in that it uses a slurry of finely-ground coal digested under ordinary field conditions. Most research of this type is carried out in sterile laboratories.

Dr Gilmore sees this approach as making the jump to commercialisation easier in the future. Thermal power stations could have special slurry ponds to treat the coal before combustion, cutting its pollution potential drastically.

With a provisional patent under way and intense interest from researchers overseas, the sulphurous microbes look like having a well-fed future.