Adding a simple textile dye can increase the methane yield of coal seam gas wells by a factor of 10, researchers from the University of New South Wales (UNSW) have found.

The discovery could breathe new life into old, exhausted wells, reducing the need for new ones.

It could also improve the economics of renewable biogas energy production.

Methane-producing microbes occur naturally in oxygen-poor environments, and are adept at harvesting the energy released as they break down organic matter, such as that found in coal seams.

The methane produced by these microbes, along with geologically-produced methane, is collected as a fuel from a growing number of coal-seam gas wells across Australia. Since the late 1990s, this coal-seam methane has formed a growing chunk of our domestic energy production.

But coal-seam gas wells are only viable producers of methane for a relatively short period, before extraction costs outweigh the yield.

Now, the researchers have found that some microbes’ natural ability to produce methane can be boosted by the addition of a simple, artificial dye that has been used in the textile industry for over a century.

The University’s Associate Professor Mike Manefield says that the addition of a dye called ‘neutral red’ to subterranean coal seams results in formation of long, needle-like crystals that improve the microbes’ ability to harvest energy. That improvement increases both the number of microbes and their efficiency – in both cases, boosting methane production.

“We’ve tested it in the lab and in underground coal beds,” Mike says.

“And we believe we can achieve a tenfold increase in methane production.”

For more information:
University of New South Wales
Marisa Cardoso
+61 2 9385 4283
m.cardoso@unsw.edu.au

Banner image: Crystals of the dye ‘neutral red’ boost gas production (shown here under fluorescence microscope).
Credit: Sabrina Beckmann