Greetings Hakan,
I feel fairly confident that biological degradation will have a lower energy cost than pyrolysis. All of the reactions from oxidation of the lignin to hydrolysis of the cellulose occur at or below 35 degrees C. The conversion to alcohol by biomass occurs at that temperature too. It is a question of the heat input for distilling the alcohol to 95% purity vs the pyrolysis heat input. There are ways of driving off the water from 3A molecular sieve used to get to 100% purity that do not require extremely high temperatures but do require significant time. I´ve never tried removing the water from the sieve with a solar oven but it is an option. Of course both systems require lab infrastucture. Please keep in mind I´m strongly biased toward microbial systems as that is my background. I don´t rule out physical chemical methods. It´s just not part of my experience base.
Tom Irwin
From: Appal Energy [mailto:[EMAIL PROTECTED]
To: Biofuel@sustainablelists.org
Sent: Thu, 04 Aug 2005 20:30:20 -0300
Subject: Re: [Biofuel] Cornell on ethanol, biodiesel, & hydrogen energy efficiencies
> I could be missing something, this is probably too simple an analysis.
Perhaps the process requires the entire equation to make sense? Maybe
cradle to grave energy inputs on both sides as well as energy outputs
are required to get an accurate perspective as to energy related
cost/benefits of cradle-to-grave production?
The process of converting biomass to methanol requires pyrolization
(thermochemical) reactors which convert the biomass to crude producer
gases. (See 19th century gas street lighting and the process of charcoal
production.) After "washing" the producer gas, primarily hydrogen and
carbon monoxide, it is converted to methanol under high temperature and
pressure in the presence of a catalyst.
The producer gasses can be used directly in the production of
electricity (supplanting natural gas), powering engines (see gasifier
tecnologies from the mid-20th century), whether they be stationary (low
pressure feed) or mobile (high pressure storage).
The production of synthetic gasoline can also be implemented using
methanol as a feedstock.
http://www.fpl.fs.fed.us/documnts/pdf1991/zerbe91a.pdf
In any event, btu per gallon vs. btu per gallon, methanol has only 75%
the energy value of ethanol.
http://www.leeric.lsu.edu/bgbb/7/ecep/auto/m/m.htm
That said, using 146 bushels of corn per acre,
http://www.agry.purdue.edu/ext/corn/news/articles.03/CornYldTrend2003.html
and an ethanol yield 2.5 gallons per bushel,
http://www.fsa.usda.gov/daco/bioenergy/2001/2001FactorsNFormulas.pdf
you gross approximately 365 gallons of ethanol per acre.
Subract the energy inputs to derive a net output.
Presuming 86 gallons of methanol per ton of dried biomass,
http://bioenergy.ornl.gov/forum/94fall.html
a dry ton/acre of 9 tons for hemp,
http://www.ratical.org/renewables/biomass.html#f12
or 5-8 tons/acre of non-irrigated willow,
http://www.esf.edu/willow/PDFs/2004%20esa_sustainability.pdf
you gross between 430 and 774 gallons of methanol per acre.
Some claims are made relative to 100 gallons of methanol per dry ton of
cannabis hemp. If true, this would elevate per acre production of
methanol to approximately 900 gallons.
Using an energy content multiplier of 0.75 yields numbers between 322
and 675 units of equivalent energy when producing biofuel from methanol
in comparison to ethanol.
The balance of the equation between methanol and ethanol lies in the
energy input sector.
The input/output ratio for ethanol seems to slide somewhere between
1.00:1.25 and 1.00:1.40. That would equate to a net energy gain between
91 and 146 gallons per acre.
At present, I don't have access to the energy input information for
methanol derived from dry biomass to complete the methanol side of the
equation. That may or could be acquired from the Hawaii Natural Energy
Institute, pursuant to their results on their 1995 subcontract with the
U.S. Department of Energy, titled "Hawaii Integrated Biofuels Research
Program."
If someone can provide a link where this data can be obtained, the
balance of the equation can be calculated.
All printed comments on energy inputs for thermochemical production of
methanol from biomass indicate lesser energy inputs for methanol than
than for ethanol. To compare apples to apples, this should include the
energy used to produce the methanol biomass crop, inclusive of
herbicide, pesticide, fertilizer, irrigation, sewing, tending,
harvesting, transportation, pyrolysis and synthetic reformation (as the
1:1.25 and 1:1.40 ethanol ratios include similar energy inputs).
If the generally expressed efficiency comments hold true, then methanol,
perhaps synthetic gasoline from biomass derived methanol and certainly
producer gasses from biomass are considerably more efficient pursuits
than is ethanol.
Is anyone able to provide the "missing link?"
Todd Swearingen
Another link of interest:
http://bioenergy.ornl.gov/doeofd/94_95sum/biosyngs.html
Tom Irwin wrote:
> Hello Todd,
>
> Let's forgo toxicity and byproducts for a moment and talk about
> efficiency. I could be mistaken but if I can take cellulose and
> biologically convert it to ethanol or methanol, I think I want the two
> carbon alcohol over the one carbon alcohol. If it is a question of
> biologically producing ethanol and chemically producing methanol, I
> think I still go for the biological process. I could be missing
> something, this is probably too simple an analysis.
>
> Tom
>
>
> ------------------------------------------------------------------------
> *From:* Appal Energy [mailto:[EMAIL PROTECTED]]
> *To:* Biofuel@sustainablelists.org
> *Sent:* Thu, 04 Aug 2005 11:36:44 -0300
> *Subject:* Re: [Biofuel] Cornell on ethanol, biodiesel, & hydrogen
> energy efficiencies
>
> Dinosaur as a matter of necessity Tom. Economics may preclude or
> designate that necessity.
>
> What I find peculiar is the fact that the toxicity of gasoline isn't
> mentioned here.
>
> You also may care to take into consideration that energy farming will
> inherantly reduce other industrial toxicity as biomass becomes a
> constituent element within them. Mercury and sulfur reduction from
> the
> electricity generation industry comes to mind immediately
>
> If you're going to conduct a cost/benefit analysis Tom, let's do so
> across the board and include all the benefits, rather than eluding to
> but one or two specific and unquantified disbenefits, perhaps even
> disbenefits that can be ameliorated or eliminated.
>
> Todd Swearingen
>
>
> Tom Irwin wrote:
>
> > Hi All,
> >
> > I don't think ethanol will be a dinosaur in 20 years but would
> > appreciate why you think so if it is other than yields per hectare.
> > Methanol has the capacity to produce some nasty tailpipe
> emmission (as
> > does ethanol but less so) and is far more toxic to humans and
> animals
> > than ethanol. Another component of sustainability is safety. I
> would
> > not wish to see methanol filling stations. Most people have no
> concept
> > how nasty it is. Yes, it can be handled safely by those who
> understand
> > the dangers but most folks don't have that knowledge.
> >
> > Tom Irwin
> >
> >
> >
> ------------------------------------------------------------------------
> > *From:* Appal Energy [mailto:[EMAIL PROTECTED]
> <_javascript_:kh6k0("new","[EMAIL PROTECTED]")>]
> > *To:* Biofuel@sustainablelists.org
> <_javascript_:kh6k0("new","Biofuel@sustainablelists.org")>
> > *Sent:* Thu, 04 Aug 2005 10:35:58 -0300
> > *Subject:* Re: [Biofuel] Cornell on ethanol, biodiesel, & hydrogen
> > energy efficiencies
> >
> > Still, all rather sad how ethanol has become the predominate
> > alternative
> > fuel of choice for gasoline applications when methanol yields far
> > higher
> > outputs per acre with far fewer inputs.
> >
> > At 75% of the energy content as ethanol, the energy yield per acre
> > (100
> > gallons per ton of dry biomass) outstrips corn derived ethanol,
> > even on
> > a good day. The real crux of the matter would be to choose crops
> > of high
> > seasonal yield, inclusive of those suitable for pre- and post
> > plantings
> > of other crops in the same annular cycle.
> >
> > My book makes ethanol a dinosaur within 20 years.
> >
> > Todd Swearingen
> >
> >
> > Keith Addison wrote:
> >
> > > Hello Bob, Andrew
> > >
> > > Normally I'd agree with you Bob, but not in Pimentel's case,
> > that time
> > > was long ago, and now Andrew's response is not inappropriate.
> > Pimentel
> > > merits little better than scorn and derision
> > >
> > >> Andrew,
> > >>
> > >> I know you said it in jest, but the unfortunate effect of your
> > >> sarcasm regarding David Pimentel, one of the nations' outstanding
> > >> scientists, is to support the ignorant critics of good
> science who
> > >> argue that, "if I believe in a proposition, then anyone who
> > presents
> > >> evidence that contradicts my belief is a malicious fool and not
> > to be
> > >> believed".
> > >>
> > >> It is true that a few pseudoscientists acting as industry shills
> > >> will (for a fee) produce a "scientific study" supporting any
> > >> industry-desired conclusion, but your implication that
> Pimentel is
> > >> such an Exxon shill is blatant slander, and I am ashamed to see
> > it on
> > >> the Biofuels site.
> > >>
> > >> I assume that you wish ethanol's EROEI (energy return over energy
> > >> input) to be positive, thus making it a useful energy source
> as we
> > >> approach the end of fossil fuels. So do I - and so would lots of
> > >> other folks. I'm sure also that David Pimentel shares that
> > wish. The
> > >> difference between you and Pimentel is that as a scientist, he
> > says,
> > >> "It's a great idea and I hope it's true, but what if it isn't? So
> > >> let's run the numbers and seek the truth of the matter. If it
> > turns
> > >> out the EROEI is negative, we would be commiting a cruel and
> > >> expensive hoax on the nation to propose ethanol as an energy
> > solution."
> > >
> > >
> > > Not so, sad to say. Pimentel has long been aware that the data
> > he uses
> > > is outdated and wrong, but he keeps using it anyway. Implying that
> > > he's an Exxon-et al shill is not blatant slander, the question
> > has to
> > > be asked why he continues doing this, and asked of his
> > publishers too.
> > > This is peer review? I think not. It certainly is not science.
> It's
> > > propaganda.
> > >
> > >> I am as disappointed as you must be in his analysis showing a
> > >> negative EROEI. And I look forward to additional valid studies
> > >> testing and challenging his conclusion.
> > >
> > >
> > > Those have been to hand for a long time, more and more of them,
> > > debunking every aspect of Pimentel's claims. Pimentel takes no
> > notice,
> > > neither do his publishers.
> > >
> > >> But to lampoon his work because you don't like the color of -
> > was it
> > >> his socks? - is not a worthy act on your part.
> > >
> > >
> > > Well, I don't know, I suppose we can take his socks about as
> > seriously
> > > as the rest of him.
> > >
> > > Nothing new here - we've been discussing Pimentel's repeated and
> > > rather successful disinformation campaign since early 2001. As
> John
> > > said when he posted this latest bout, he does it every year.
> > >
> > > Please see these recent messages, to put it in perspective:
> > >
> > >
> >
> http://www.mail-archive.com/biofuel@sustainablelists.org/msg52605.html
> > > Re: [Biofuel] Cornell on ethanol, biodiesel, & hydrogen energy
> > efficien
> > >
> > >
> >
> http://www.mail-archive.com/biofuel@sustainablelists.org/msg52756.html
> > > Re: [Biofuel] Cornell on ethanol, biodiesel, & hydrogen energy
> > efficienc
> > >
> > > Best wishes
> > >
> > > Keith
> > >
> > >
> > >> I'm sure you can do better. I hope you will.
> > >>
> > >> In all sincerity and hoping that your future jests will be more
> > benign,
> > >>
> > >> Bob A.
> > >> ----- Original Message ----- From: "Andrew Lowe"
> > >> To:
> > >> Sent: Monday, August 01, 2005 4:15 AM
> > >> Subject: Re: [Biofuel] Cornell on ethanol, biodiesel,& hydrogen
> > >> energy efficiencies
> > >>
> > >>
> > >> Michael wrote:
> > >>
> > >>> This press release below produced the AP story that follows it.
> > >>>
> > >>> July 5, 2005
> > >>> Cornell ecologist's study finds that producing ethanol and
> > biodiesel
> > >>> from corn and other crops is not worth the energy
> > >>>
> > >>> By Susan S. Lang
> > >>>
> > >>>
> > >>>
> > >>> Chris Hallman/University Photography
> > >>>
> > >>> Ecologist David Pimentel, shown here pumping gas, says that his
> > >>> analysis shows that producing ethanol uses more energy than the
> > >>> resulting fuel generates. Copyright © Cornell University
> > >>>
> > >> [snip]
> > >>
> > >> Sorry for the late reply on this one, but with dress sense like
> > what
> > >> was shown in the picture how can anyone take this bloke
> > seriously? I ask
> > >> you. Also with that posture and the look on his face, has
> > anyone checked
> > >> for a pulse? It reminds me of an episode of "The Goodies" where
> > they
> > >> where shown using the Russian Politburo as glove puppets -
> > aahhh I see
> > >> it - if you squint at the part between his left leg and the
> car I'm
> > >> sure I see an arm with an Exxon logo on it.......... ;)
> > >>
> > >> Yours in jest,
> > >> Andrew
> > >
> > >
> > >
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