Coal Mines: Maximizing Available Fuel Resources at Mining Sites

Coal mine methane (CMM) gas is a byproduct of coal formations in subterranean coal seams, and is released before or during active coal mining. Coal mines emit methane at approximately 400 million metric tons (28 billion cubic meters) of carbon dioxide annually – equivalent to the consumption of 818 million barrels of oil or the carbon dioxide emissions of 64 million passenger cars.

Caterpillar has developed generator sets specifically for use with CMM gas. Implementing methods to use this gas as an alternative fuel can help:

• Improve mine safety
• Mitigate carbon dioxide release into the atmosphere
• Reduce electricity costs
• Generate revenue

Cat^® Dealers provide enclosures, fuel train components and PLC-based paralleling switchgear to either export the power produced to the local electric grid, or utilize it at the mining facility. They also offer:

• Large project development and design expertise
• Logistical and technical installation support
• On-site maintenance

 
How It Works

CMM emissions can be significantly decreased through the recovery and utilization of drained gas. The CMM is sequestered and used for fuel in reciprocating gas engine generator sets. This mature and proven technology is highly effective for gas mitigation and power generation.

When CMM is removed from the ground, it is held in large tanks and pretreated for use in gas engines. Pretreatment includes filtering for dust and particles, drying the gas and sending it through a pressure-regulated fuel train to on-site generator sets.

Cat CMM gensets provide:

• Customized engine control systems to handle regular fluctuations in gas methane content
• A fuel system designed to accept very low-pressure gas, typical of a coal mine ventilation system

Coal bed methane (CBM) is another gas associated with underground coal seams. CBM can be extracted from coal deposits before or even in the absence of an active mining operation for use in power generation applications. CBM gas typically has a higher methane content and less carbon dioxide than CMM, and can often be used in a natural gas reciprocating generator set with minimal fuel treatment or customization of the fuel system.

Learn more about Coal Mine Methane in our Interactive Video