Two Claims, Four Indexes: Coal Mine Methane and Emission Credits
Coal mine methane, coal bed methane, coal seam methane, coalbed natural gas: all terms for the same thing — it is the natural gas found in coal deposits. In the US it accounts for about 8 percent of natural gas production, according to the US Department of Energy’s National Energy Technology Laboratory. Per NETL, “a cubic foot of coal can contain six or seven times the volume of natural gas that exists in a cubic foot of a conventional sandstone reservoir.” This gas represents a potential energy source, and a significant safety concern for underground coal mines.
Inventors Kuninori Ito and Michio Abe, both of Yokohama, Japan, have developed technology to use the energy contained in coal mine methane and obtain greenhouse gas reduction credits.
Their invention is documented in US Patent Number 7,587,999, “Gas engine electric power generating system effectively utilizing greenhouse gas emission credit,” and is assigned to Mitsubishi Heavy Industries, Ltd. of Tokyo, Japan. The patent date is September 15, 2009.
The patent has two claims; the first being rather long, I won’t repeat it here. We’ll let their patent abstract tell the story:
“A gas engine electric power generating system in which an electric power generating apparatus including an electric power generator connected with a gas engine of a pilot fuel oil ignition type is installed near a coal mine. Recovered methane gas and ventilated methane gas from the mine are introduced into a cylinder of the gas engine while being adjusted to be introduced as a lean methane/air mixture to operate the engine to produce electric power. A carbon dioxide emission credit reflecting the difference in greenhouse effect index between releasing coal mine methane gas to the atmosphere and releasing the methane gas to the atmosphere as carbon dioxide, is registered on an emission credit market. Also included are the affiliated systems of mutual patronage relation constituted by one or a plurality of the systems and nearby power generating system or systems using coal bed methane or pre-mining gas as fuel.”
A unique aspect of this patent is its crossing into four patentECO Indexes. Its original classification of 123/3 (Internal Combustion Engines | Combined Devices | Generating plants) places the invention in the patentECO Energy Index. The carbon emission reduction aspect (capture of methane) is related to inventions in the Air Index. The emission credit feature is a business method (705/37, one of the cross reference classifications) found in the Industry Index. Application of Ito and Abe’s invention to the coal mining industry overlaps with the patentECO Resource Extraction & Harvesting Index.
4/7 = 57% of the patentECO Indexes covered by one, two-claim patent. Not bad; we doff our chapeaux!