[Gasification] OT Gasification and ethanol production from biomass

[Mark Ludlow]

Harmon & List:

I've made anhydrous, not in my back yard but at the pilot plant scale and
while it's not rocket science it's not a no-brainer either. First you need
the alcohol/water azeotrope which is 95% ethanol. Typically this is done at
reduced pressure of there is a suitable heat sink available to cool a
condenser or more likely with a distillation column.

>From here you can employ a molecular sieve such as zeolite to absorb the
water. Problem is, zeolite adsorbs only about 20% of its mass in water and
its desorption energy requirement is significant (due to its high cost, it
must be regenerated a number of times). Better have some high-grade waste
heat handy.

The other method that I am familiar with is to use something like toluene
(methylbenzene) which, while hardly soluble at all in water, forms a lower
boiling point azeotrope with it allowing it to be stripped from the alcohol.

Most stills use some form of reflux so the process becomes multiple pass,
bleed-and-feed.

Now surely all this could be done in the woods with a coil of copper pipe
and an iron mash kettle, but if there is some magic kludge that makes
200-proof easily I assume that the ethanol industry would have heard of it.
Maybe suitable membranes for ethanol will be devised. I think that the exist
for isopropyl alcohol.

Mark

-----Original Message-----
From: gasification-bounces at listserv.repp.org
[mailto:gasification-bounces at listserv.repp.org] On Behalf Of Peter Singfield
Sent: Friday, June 01, 2007 7:41 AM
To: gasification at listserv.repp.org
Subject: Re: [Gasification] Gasification and ethanol production from biomass

At 09:03 AM 6/1/2007 -0500, you wrote:
>Mark Ludlow wrote:
>   And, BTW, getting 100% is not really all that difficult for
>individuals -- ask the guys who make anhydrous ethanol to use to make
>biodiesel. It's definitely doable in the backyard, and not too expensive
>to set up.
>-- 
>Harmon Seaver


Anhydrous ethanol is the preferred "product" if it can be indeed achieved
on micro scale.

Sounds like it is being accomplished -- can you supply more leads??

The main reason "anhydrous" is preferred is because it can mix with
gasoline and be used as fuel -- as is -- in any modern vehicle then -- as
Harmon just demonstrated.

(oh -- also can be mixed with diesel fuel and run in a normal diesel engine
-- no9 changes required!!)

Aguahol requires major changes in the IC engine to run efficiently. And
will not mix with other fuels. That engine become mono-fueled for aguahol
only after.

Theoretically -- in this area -- small farmers could deliver cane to a
small centralized factory that would then produce power and portable fuels.

There is no reason that compressed bio methane can't eventually replace
butane for cooking purposes either. A small factory could support the cost
of the compressing process -- extracted food grade CO2 always has local
economic value -- the soft drink industry.

Thus this even becomes on topic for the stovers!!

Peter/Belize

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