Green Gas' Views on Low Concentration Methane: Safety First

Green Gas is committed to harnessing as much coal mine methane (CMM) as is possible for methane use: the results are clean energy production and significant reductions in greenhouse gas emissions.  But it is our view that methane needs to be transported and used at safe concentrations, meaning well above or below the explosive methane concentrations of around 5 - 15%.  Mine safety authorities around the world agree and have in place safety regulations that are important for the protection of worker safety.  We at Green Gas believe that improved gas drainage is the best answer to create a supply of CMM at concentrations safe for transportation and end use.

Green Gas believes that it is nearly always possible to produce drained gas at concentrations of over 30% methane. The good news is that this higher concentration gas is intrinsically safe: if a stray igniting source intercepts this gas, there is no explosion and a flame cannot propagate in a pipeline. The other good news is that, while secondary to safety benefits, the production of higher concentration gas has extra financial benefits. Gas pipelines can be smaller and less expensive, and cost of pumping higher concentration methane out of a mine is significantly lower. It is also possible to use higher concentration CMM in more ways and possibly at lower cost.

Below are some sources addressing the issue of low-concentration mine gas, and also a letter that Green Gas and Sindicatum Carbon Capital sent to the International Energy Agency (IEA) in response to their report on coal mine gas in China.  The IEA has prepared an addendum to their report that addresses the safety concerns our letter outlined. 

The IEA report and IEA's addendum may be found at:

 http://www.iea.org/textbase/subjectqueries/methane.asp

A letter to IEA:

"Letter International Energy Agency 19 May 2009"

A letter published in The Insider, CMM Recovery and Utilization Initiative Guizhou Province, China, January, 2008, Issue 2:

http://www.gzcmm.org/Newsletter/Winter_2007_English.pdf)

"Letter Published in The Insider"

A detailed Analysis of Use of Low Purity Gas in Engines, prepared by Green Gas Subsurface Methane Control Department:

"Analysis Low Purity Gas"

A "Best Practice Guidance for Effective Methane Drainage and Use in Coal Mines" sponsored by UNECE and M2M and co-authored by Green Gas personnel can be downloaded from:

www.unece.org/energy/se/cmm.html