[Stoves] [Gasification] Path from Biomass to Ethanol by way of Ethane.

[Paul S. Anderson]

Mark,

Well stated!!!!!!!!   It is heavy reading, but it is scientific and not just
opinions or simplistic statements.

I have not snipped it so that those who passed it over will have a chance to
read it below.  And I have added the Stoves list serve so that those readers
can also see it.  (Sorry that some of us receive multiple copies, but we have
chosen that option because of our range of interests.)

Paul
-- 
Paul S. Anderson, Ph.D., Geography professor - Emeritus
Telephone:  USA-309-452-7072 (residence and office)
Internet site:  www.ilstu.edu/~psanders
For my gasifier stoves info, go to:
http://bioenergylists.org/contributors#Paul_Anderson


Quoting Mark Ludlow <mark at ludlow.com>:

> Dan,
>
> Converting a crystalline, linear polysaccharide such as cellulose into food
> that the yeast Saccharomyces cerevisiae can convert to ethanol and CO2 is
> tough. Even Ma Nature has not figured out this problem, at least in the more
> successful way that she has employed photosynthesis to split oxygen from
> hydrogen in water. All bio-schemes I am aware of require virtually as much
> energy to reduce cellulose biomass to particles small enough to provide
> sufficient surface area for the de-polymerizing enzymes to work, as is
> recoverable in output energy. We all know that fungi are quite efficient at
> breaking down woody biomass (and wooden boats, fence posts, etc.), but not
> in a manner that lends itself to practical energy production. Even corn
> conversion to ethanol requires an amylase to reduce the branched-chain, corn
> starch into a simple sugar usable by Saccharomyces cerevisiae.
>
> Anaerobic digestion favoring methanogenic bacteria requires a fairly
> specific environment and still needs lots of comminution of feedstock (read:
> chewing of cud), unless we hire some herbivores to do it for us and harvest
> their reduced-quality end-product (manure).
>
> I think gasification is the logical reduction method for every feedstock
> that cannot be efficiently bio-converted or bio-digested. In a perfect
> world, the sludge from methane-producing digesters would be used as a soil
> amendment to assist in the growing more corn or other relatively-easily
> convertible feedstock. Bio-sludge (there may be an image problem with this
> name!) is everything remaining after fermentation or digestion with the
> intention of recovering inflammable liquids or gases. All other woody
> materials would be targeted toward gasification, until that point in our
> scientific evolution that efficient enzyme-mediated bioconversion would
> become net-energy competitive (don't hold your breath).
>
> With respect to gasification, much discussion on this List is dear to my
> heart: how to "get off the grid" and reduce exposure during the inevitable
> crunch coming when the manure hits the ventilator and cheap, energy-dense
> oil is priced by the gram, not barrel. However, civilization on Earth will
> little benefit from a further segregation of humanity into those with
> "five-acres and independence", and those unlucky enough to live without any
> means of becoming energy self-sustaining.
>
> The problems we face as a civilization, we created as a civilization. Coal
> ushered in the Industrial Age. And coal may be the bridge to a more
> enlightened energy economy that combines biological processes (mimicking
> nature) as well as advanced industrial processes such as biomass
> gasification, that provide feedstocks which produce building blocks for
> industrially useful chemicals which are now petrol-derived (out of sheer
> convenience). When the chemical process industry is forced to re-focus on
> something besides cracked petroleum products or natural gas-e.g. a
> normalized version of woody biomass distillation-it will respond with new
> processes and commodity intermediates.
>
> Those who wish to capture fly ash, remove tars, reduce CO2 to CO and
> generally improve the quality of gasification products are all part of the
> total solution. So are the horticulturists who lead us to planting those
> particular species of plants that are optimized in their primary function of
> converting solar radiance, CO2 and H2O (with some nitrogen and other
> nutrients that our bio-digesters supply) to carboniferous biomass.
>
> Gasification is the single, most-tolerant method of converting biomass to
> useful forms (except for a crackling campfire).
>
> Mark Ludlow
>


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