I admit I know little about Coal mining but an article online on supplying Britain's future gas needs, suggests that there is methane that could be extracted from old coal mines.
Is this actually feasible?, I thought methane occured in pockets in coal mines, not in one big extractable mass.

---

methane extraction drilling ahead of working faces is a long-established technique. Foraky had two or three rigs doing this full-time in the 70s and early 80s.

I don't know much about it, but it must work.

---

This company recently drilled in S. Wales, (last year) about 1/2 mile from my house.

http://www.alkane.co.uk/ 

They were drilling down about 250 metres to a roadway in a disused mine and had a fair bit of trouble steering the drill to the desired point, (drill head motor and other complex bits of kit).

I could not see the point as the mine is bound to be flooded and where would the gas be?

They left a standpipe and valve and nothings been heard since.

There has been talk of doing it here in North East Wales for a few years.
Not sure anybody has actually done anything about it yet though.

It obviously works in the right circumstances as Tower Colliery were running six large engines off the methane drainage borings in advance of the coal face, there was also a rumour that they would run a new power plant off the methane trapped when the shaft was capped.

The only other bit of info I picked up was that there has been shift in Government policy (grant aid etc) which has made exploration less attractive.

In the 1960s in Lancashire it was fairly commonplace to extract the methane from the coal face by drving borings ahead into the seam and then pumping it up to the surface. Once on the surface the methane could be used to fire the boilers. Sutton Manor Colliery ran two winders, two steam compressors, the fan engine and the turbo alternator of the steam fired by the methane they extracted - then some unsung genius replaced steam engines (capital cost paid up years ago) with new electric motors and stopped using the methane, result ? Profitable colliery promptly lost money, was deemed uneconomic and closed...

Grahami

---

There's loads of information available on this page:

Coal Authority http://www.coal.gov.uk/publications/miningtechnology/index.cfm 

Spoke to someone at work who worked in a coal mine, who said same as everyone else, gas tapped off was either burnt off or used in small scale applications.
I wonder whether the article (on MSN-UK) was thinking of extracting gas from coal as done years ago.

" In the long term, however, improved techniques may mean Britain too has the benefit of the same kind of gas bonanza as the US is currently enjoying. Many of the country's old coalmines are full of methane, which can perhaps be extracted."

Are these old coal mines really "Full of methane" waiting to be tapped or is this speculation by journalists?

---

There has been talk of doing it here in North East Wales for a few years.
Not sure anybody has actually done anything about it yet though.

I was taken round Point of Ayre Colliery (on the north Wales coast near Prestatyn) sometime in the 1960s and the roadways there had pipes driven into the surrounding ground with connections to a main running along the roadway.

I seem to remember being told (either then or on another occasion) that the gas was injected into the national gas grid (this would be about the time of the conversion from towm gas to north sea gas) but I can't be sure about this.

Dave

Dave

davel wrote:- I was taken round Point of Ayre Colliery (on the north Wales coast near Prestatyn) sometime in the 1960s and the roadways there had pipes driven into the surrounding ground with connections to a main running along the roadway.

I seem to remember being told (either then or on another occasion) that the gas was injected into the national gas grid (this would be about the time of the conversion from towm gas to north sea gas) but I can't be sure about this.

Like davel I had a trip around Point of Ayre. In my case it was in the early 60's probably about 8/9 years before North Sea Gas reached N Wales. Two of the many things which stand out as memories of that trip were:-
1. The almost paranoid precautions to avoid the risk of sparks. It was explained that this was a very high methane mine and that the precautions were necessary. To go underground we had to relinquish all our clothing footware etc and use only the provided boots, socks, boilersuits and paper underwear. One member of our party was refused permission to go underground as he could not pass a simple eye test without his glasses which were of an NHS design with coiled spring steel ear pieces (older readers will remember these glasses, some called them 'Billy Bunter glasses').
2. The ventilation was amazing, in the main underground roadway the air must have been moving at 12-15 mph. Again it was explained that this was to keep the methane level down to acceptable limits.

Years later, after North Sea Gas had arrived I remember being told that methane was being extracted and pumped into the N Wales gas main.

Years later again, a coal to liquid fuel experimental pilot plant was built there and I believe this was powered by some of the extracted methane. Needless to say this never seemed to progress beyond the experimental stage.

Sometime ago I found this http://www.berr.gov.uk/files/file18655.pdf  which around page 20 onwards lists the UK coal fields and some of their properties including presence, quantity, and use of methane.

---

There's

Coal Mine Methane (CMM)

Abandoned Mine Methane (AMM)

Coal Bed Methane (CBM)

CMM is from producing mines, AMM obviously from abandoned mines and CBM from the unmined coal seam.

The current UK activities are listed on the Coal Authority page
http://www.coal.gov.uk/publications/miningtechnology/coalminemethaneukactivity.cfm 

As we are all well aware the Government has this week released it's plan for nuclear power stations. Depending which lobby you support ..... a good or bad move. Regardless some say too late we'll still have problems in the next 10 -20 years.

During the last few years the Government has been encouraging what is known as "distributed generation" For those of us old enough to remember this is modern parlance for producing electricity locally to where it is needed thereby reducing the waste in energy along the transmission lines and the gross waste of heat at the power station end. They have also de-regulated the energy industry by encouraging small scale energy production with heat recovery. Commonly known in the UK as CHP (Combined Heat & Power) or Co-generation elsewhere.

What must be one of the biggest players in this game is a company called Ener-g. Among the various approaches they have and are making is the use of mine gas. http://www.energ.co.uk/mines_gas_generation 

I am currently heading up a natural gas engine/CHP development for my company. It is very interesting work and the energy claw back is quite amazing. If the unit is correctly sized for the application then I consider it a useful piece of the jigsaw that is "energy conservation".

If the unit is correctly sized for the application then I consider it a useful piece of the jigsaw that is "energy conservation".

There is always some difficulty in harmonizing the power and heat loadings.
The last place I worked had two 5 MW gas turbine/alternator sets delivering exhaust heat to two boilers with added heat from duct burners in between.

The plant provided all steam for a paper mill and the electricity was fed into the grid, during maintenance on the turbines we had a gas fired shell boiler to provide steam.

The contract with the company that supplied the generating plant and its maintenance was such that there was no real operational advantage for the mill, it is fair to say it was only installed due to grant aid derived from taxes on cheaper power supplies.

However, in defence of CHP plants I would add that we failed to get the best configuration of plant due to cost constraints.

As Toadstone said, a good conservation measure where it can be applied.