"The only thing green about biomass are the profits," said Margaret Sheehan at the Energy & Economy Session III this afternoon. Dave Atkins provided a different perspective; "If you don't grow it, you mine it … so biomass power is green, but various shades of green." So this debate is revolving around whether woody biomass (which is distinct from trash-based biomass) is a good thing in the combustion cycle. Does this sound like the complete biomass picture?
I was surprised that this panel of experts didn't touch on the advanced methodologies of the combustion cycle. We can accept the fact that, if you burn a tree, you produce more CO2 and NOX than from the same amount of coal. This is basically a question of the "carbon portfolio" in the host fuel. When I burn it (that is, break the carbon-carbon bonds), I get a different type of energy depending not the type of bonds that I break! But when considering emissions, the process that we use is a much more important variable.
With this in mind, why aren't we talking about carbon capture and sequestration? We have a handful of very effective methods (including gas adsorption, membrane separation, and CO2-H2O condensation) to separate carbon dioxide from the system, and we have made significant progress on sequestration technologies (including saline sinks, gas-in-shale injection, clathrate hydrate storage, and deepwater sequestration). If we look at using these technologies with biomass processes, then the carbon output is significantly reduced. Perhaps these folks can't touch that topic because it's outside their expertise, but the current discussion of biomass is incomplete.
More importantly, why aren't we talking about biofuels conversion? There is a new report from NREL that is incredibly exciting on this topic, and I would suggest that anybody interested in biomass read it!