Friday, October 01, 2010

Biomass Energy & Carbon Accounting (Part 2)

In our last post on "Biomass Energy & Carbon Accounting" we cited an engineering science reference from the U.S. Department of Energy's National Energy Technology Lab (NETL) that ~50% of carbon emissions can be captured through oxygen starved biomass gasification technology.

In our extensive experience with biomass gasification, we feel uncomfortable with the NETL estimate -- concerned that the carbon capture percentage may be too high. Our "educated guess" is the percentage would be closer to a +30% carbon capture for commercially available biomass gasifiers (i.e., up-draft gasifier) -- which is reflected in below amended chart.



While we could be wrong (overly conservative) so could NETL.

The problem in getting a handle on the issue of carbon capture is the lack of commercially operating biomass gasifiers (providing much needed engineering data). On the topic of carbon capture (biochar), the majority of engineering science work has been either at lab scale or with small gasifiers (i.e., stoves). It should be remembered that while biochar has always been a waste product of biomass gasification, only recently has it become a critical issue. Critical in the sense of the very viability of biomass power, recognizing current questions on carbon neutrality (i.e., the EPA's Tailoring Rule").

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