Agreed...any mechanical process will require repair and...

Agreed...any mechanical process will require repair and maintenance and backup/fail safes measures would need to be in place.

The reason I was attracted to CHTD is that it:

a) uses only 2% of the inherent energy in the brown coal to convert to BCE as it uses head pressure and gravity to create the pressure and heat required for the decarboxylation reaction.

b) it is a free standing tech ie. it does not require a 3rd party energy or heat source to function. Therefore it can be used outside of LV and away from power plants.

c) it creates a slurry which can be transported, therefore overcomes BC's tendency for self combustion and subsequent transportation issues.

Of course, initially digging and then operating 1 km down is going to be more of a challenge than a plant located at ground level.

Time will tell whether this tech has the legs or not.

Cheers K