[Bioconversion] combined cycles

[AJH]

On Tue, 19 Jun 2007 12:50:07 +0930, Paul Harris wrote:

>Any conversion of energy is inefficient, so wastes our precious
>bioenergy - <snip>

I agree but need this always be so? 

I think the first coal fired engines were about 1/4% conversion
efficiency but now direct fired coal gas turbines in combined cycle
are said to achieve over 50% conversion.


We're now seeing micro chp being deployed embedded in gas condensing
boilers in beta tests and it strikes me biomass to energy stands to
gain better from such integrated schemes.
>
>Gaseous fuels are best suited to stationary applications and any liquid
>fuel will be needed for "emergency" uses.

Maybe but it's economics that will dictate.

A few days ago I asked a question about the amount of remaining carbon
is digestate slurry after  an "economic" residence time in a biogas
digester. The reason I asked is because UK government has moved the
goalposts again and there seems to be more emphasis on digestion of
specially grown rawstock. Like you everyone involved seems to think
the "spent" slurry should be returned to land. I just wonder if there
is scope for working a pyrolysis gasification process in series with
it?

AJH