What is Waste Coal Mine Methane?

The coal formation process causes methane to form within the coal seam, which is then held in the seam until disturbed, such as through coal mining. The coal mining process has always required the methane be removed, but originally it was for safety reasons, where as now there are also strong environmental considerations for draining and utilising the gas.

Methane is a safety concern for the mine both because it is highly flammable and because it is hazardous to breathe without proper ventilation. When methane content in the air is between 5 and 15% is present with oxygen the gas can explode and can also kick off coal dust explosions which can have catastrophic consequences. As such, removing the methane is an important part of any mine safety process. Traditionally the methane has been either flared or released directly into the atmosphere.

While these safety concerns are still very important, removing and utilising the methane also has an environmental benefit. Methane is a particularly potent greenhouse gas, at approximately 21 times the global warming potential of carbon dioxide. By capturing and burning methane it is converted into carbon dioxide and water, which provides significant carbon emission abatement as well as the power generation benefits.

As [the world] becomes more ‘carbon constrained’ there is an increasing incentive to be abating the emissions released by the coal mining process. The Envirogen solution provides significant abatement due to the emission intensity of methane, while at the same time providing power generation from a resource that would otherwise be wasted.

The Envirogen power stations will abate approximately 1,423,000 tonnes of carbon dioxide equivalent per year. That equates to removing approximately 314,000 cars off our roads and at the same time the power station generates enough power to provide electricity to 43,860 homes.

The table below illustrates the different types of coal mine gas extraction, which can be used on different types of mines, and at different stages of the mine life.

Home