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By technology classification

Osaka Gas believes that technologies serve as the foundation of corporate competitiveness, and considers R&D to be one of the most important elements in the strategy to make a difference.
For this reason, Osaka Gas works actively on R&D and commercialization of new technologies, as presented below.

Low-concentration coal mine methane concentration technology to make efficient use of coal mine methane gas released into the atmosphere


Coal mine methane (CMM) gas with 30% or less methane concentration (low-concentration CMM) has been usually flared or vented to the atmosphere after extraction from coal seams to ensure safety of workers mining coal, serving as a contributing cause of global warming. Osaka Gas has been working on developing a low-concentration CMM concentration technology to utilize otherwise unused low-concentration CMM as fuel for gas engines, gas boilers, etc. and to promote energy-saving and environmental protection efforts.


  • 1. Enables concentration of low-concentration CMM with Osaka Gas's proprietary carbon material technology, adsorbing methane selectively from an air-methane gas mixture.
  • 2. Enables utilization of methane gas released to the atmosphere with its global warming potential 21 times higher than carbon dioxide. A reduction of green house gas emissions by conducting one standard commercial unit (CMM flow rate: 2,000 m3/h) is expected to be approximately 40,000 t-CO2 a year.
  • This technology enables use of low-concentration CMM (which has been released into the atmosphere) for various applications. For example, concentrated CMM can be used as fuel for gas engine and gas boilers as well as city gas for households and industrials.

Achievements and future efforts

In fiscal years 2007 and 2008, Osaka Gas formed a joint research consortium (comprising five companies including Chinese enterprises) to undertake a joint research project for "Development of Methane Concentration Technology Aimed at Effective Use of Low-concentration CMM (Coal Methane Gas)," under the auspices of the New Energy and Industrial Technology Development Organization (NEDO). A demonstration plant to concentrate CMM (CMM flow rate: 1,000 Nm3/h) was built at the Fuxin Coal Mine in Liaoning Province, China, and low-concentration CMM extracted from the coal mine was successfully concentrated through the demonstration.
Currently, Osaka Gas has licensed this technology to a Japanese engineering company. The company is promoting commercialization of this technology in China.

Pilot plant

Pilot plant

Specifications for standard commercial units


Process capacity 2000 Nm3/h
Concentration performance 25% or more
Methane recovery rate 90% or more
Operation Automatic operation at the touch of a button
Energy savings Approx. 3,000 kL/year
Greenhouse gas emissions reduction Approx. 40,000 t-CO2/year

* Concentration performance (%) = Methane concentration of product gas − Methane concentration of feed gas

* Methane recovery rate (%) = (Methane concentration of product gas × Integrated volume of product gas) ÷ (Methane concentration of feed gas × Integrated volume of feed gas)