ZadigI feel there are a few "issues" with using underground...

Zadig

I feel there are a few "issues" with using underground gasification within an underlying coal seam to de-stress an overlying coal seam inoder to increase permeability and recovery of coal seam gas from that seam.

Firstly, ucg syngas is hydrogen rich and of lower calorific value than methane rich coal seam gas ... so if you were looking to use both ucg syngas from the lower seam and then subsequently coal seam gas from the upper seam I doubt you could use the same turbines in a gas fired power station ... maybe less efficent and cheaper boiler or reciprocating equipment could be used to generate electricity from the syngas?

Secondly, ucg recovers about 75-80% of the energy locked up in a coal seam by a controlled combustion reaction which converts the coal to syngas whereas coal seam gas recovers only about 5% of the energy in a coal seam extracted as gas from the pores and fractures within the coal. Expressed another way, for the same energy output coal seam gas requires 15-16 times the area of ucg.

So, 1500-1600PJ of syngas would have to be created and used via ucg in a deeper coal seam to de-stress an equivalent thickness overlying seam from which just 100PJ of coal seam gas could be extracted ... why not just concentrate on ucg???

Because of "arching" effects, I doubt it would be effective to operate ucg over just portions of the underling coal seam.

Thirdly, I still believe the Lorraine coals are way too deep to use ucg with present technologies ... the optimal depth I recall is something like 150-400m ... its been a while since I checked, but think the Lorraine coals are deeper than 900m.

Just my thoughts.

Have you heard anything of the group doing due dilligence on electricity production using EPGs Gazonor coal mine methane? They had some exclusivity until Oct or Nov?

Cheers
Dex