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Juicing crop feedstock for ethanol - Page 8

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Posted by John B. Slocomb on April 24, 2010, 12:51 am


If and when you build this device it would be interesting, at least to
me, if you would report on any problems, solutions, and effectiveness
of the devise as, who knows? I might want to go into the crushing
business some day :-)

Also some overall information on the feasibility of the project would
be nice. How many gallons in the tank from an acre, etc.

John B. Slocomb

Posted by Curbie on April 24, 2010, 5:13 am


The idea stems from what in my view is the best DIY alternative-energy
"return on investment" which I think is solar domestic heating, and to
size a solar heating system it must be designed to provide enough heat
for your house in your location's coldest month.

A properly built DIY solar domestic heating system can break-even in a
fairly short time, which is great, but that investment only works at
100% capacity in the coldest months of the year, and produces excess
(unused) heat as the months get warmer.

So the goal was to find something of equal value to do with the excess
heat produced in the warmer months, and ethanol gets knocked for the
amount of energy (~20,000-40,000 BTU) it takes to make 1 gallon of
ethanol which in turn produces 76,000 BTU (36,000-56,000 net). So,
I've been studying the notion of solar ethanol which seems an
interesting pair.

The quality of heat (temperature) for ethanol is higher that what
collectors can deliver so I'm studying trough concentrators:

There's a lot written on ethanol, some of the best stuff I've found
"Mother Earth Alcohol Fuel" by The Mother Earth News (FREE)

"The Manual for the Home and Farm Production of Alcohol Fuel" by S.W.
Mathewson (FREE)

"ALCOHOL DISTILLATION" by Purdue University (FREE)

"The Compleat Distiller" by Nixon & McCaw ($5.00)

Tony Ackland's web-site has the best distillation theory, math, and
forum. Although it's a spirit site, due to the legal status of
distilling spirits it's also has a great DIY forum.

Stills are the obvious and sexy part of distilling ethanol for fuel
but in my opinion people pay far too much attention on building large
stills (C803 because they're plans available, for example) and not
enough attention on either the amount of energy or feedstock it takes
to feed one, or enough attention on the principles they operate on.

Commercial farm yields for Jerusalem Artichokes are reported to be 750
- 900 gallons per acre, I'm hoping for 300 - 350 gallons per acre
following this 1983 patent:

Good luck,


Posted by John B. Slocomb on April 24, 2010, 6:48 am


It is not "heating" per se, but solar hot water was a big thing in
Indonesia. The heaters are quite visible on roofs and one could see
them as you drove through the city. I would hesitate to guess numbers
but they were certainly well distributed through the middle class, and
perhaps surprising, through the "upper class" housings areas.

One house I lived in had the system and as installed in Indonesia it
consisted of a storage tank and a pump to circulate the water through
the solar panel.

Generally one would have one of the "instant hot water heaters"
connected to your shower so you could have a warm bath on cold days
but for much of the year it provided all the hot water my wife, I and
the house maid used.
 My grand parents (in up-state New England) had hot water heat in
their house, "base board heating" I believe it was called, that worked
well. It doesn't take much imagination to connect the two systems :-)

I wonder whether some form of oil producing plant where the "juice"
can be directly used as fuel, oil palms, olives, corn oil, etc., would
be more energy economical, rather then the intricacies making alcohol,
and provide more BTU's of heat per unit also?

John B. Slocomb

Posted by Curbie on April 24, 2010, 8:43 am


I wondered about the same thing, and this is what my research
kicked-up: you can run a diesel on Straight Vegetable Oil (SVO) but
you can't start a diesel on SVO, you can start a diesel with either
Bio-Diesel (Transesterified VO),  blended VO (RUG/VO) or 2# diesel
then switch to SVO after the diesel is running.

Vegetable Oil will cause carbon build-up problems in diesels if you
don't first equalize its viscosity and volatility to the same levels
as #2 diesel, there are a lot of people experimenting with blending
and equalization, but right now Bio-Diesel is the only sure-fire
replacement for #2 diesel.

The transesterification process requires either methanol or ethanol
and since methanol is currently a fossil-fuel derivative,
transesterified VO made with it is not really a bio-fuel and is still
tied to the fossil-fuel market, requiring ethanol for
transesterification of true bio-diesel. For me anyway, since either
process would require ethanol, there are other considerations that
just made ethanol a better option.

The EPA (in the US) has cracked down and banned the importation of
most listeroid type small diesel engines so finding engines to suit
particular purposes is difficult and more expensive. Still the diesel
route would make more sense for many, but at $650 for just a small
screw-press http://www.woodnstuff.ca/oil_presses.html  this option
isn't as simple as it first might seem.

Growing the feedstock are just about a wash, and the rough comparison
looks something like this:

Crop yields:
Sunflowers for oil, about 100 gallons per acre.
JA or sorgum for ethanol about 400 gallons per acre.

At 4 to 1 yield ratio it seems an easy choice, but next you need to
account for fuel value.

SVO about 125,000 btu per gallon.
Ethanol about 75,000 btu per gallon.

SVO 100 (gallons per acre) x 125,000 (btu per gallon) = 12.5 million
btu/per acre.
Ethanol 400 (gallons per acre) x 75,000 (btu per gallon) = 30 million
btu/per acre.

The gap narrows form 4 to 1 to 2.4 to 1 in favor of ethanol.

Next we need to account for production energy, any energy used in
production which is subtracted from the total.

SVO about 12,000 btu per gallon (screw press)
Ethanol about 40,000 btu per gallon (chopping, cooking, fermenting, &

SVO 100 x (125,000 - 12,000) = 11.3 million btu/per acre.
Ethanol 400 x (75,000 - 40,000) = 14 million btu/per acre.

Again the gap narrows yet further form 2.4 to 1 to 1.25 to 1 in favor
of ethanol but SVO is getting close.

Lastly we look at the cost upgrades to the equipment and the learning
curve (mechanical vs thermal dynamics) and crop spoilage for both
seeds (which can be processed into oil for many months) and stalks or
grass (which must be fermented quickly, requiring larger
stills/equipment) so the decision has a lot to do with personal

In my view, that 40,000 btu bite for ethanol energy usage can be
reduced by solar to both eliminate cooking & fermenting energy usage
and augment distilling energy usage to bump
ethanol's advantage back up to a 2 to 1.


Posted by John B. Slocomb on April 24, 2010, 10:55 am


Once you get the ethanol, how are you going to utilize it? How are you
planning to utilize it? Burn it in a heater or power an engine with

Your message headers do not show your posting location but I assume
from your messages that you must be somewhere with a pretty mild
climate. I can't imagine doing this in the far northern states :-)

By the way, I have a 6,000 word e-mail from a guy in South Carolina
who, with his mates, is running several diesel trucks and cars on
cooking oil that they collect from restaurants. He uses both a heated
system, on one car, and a mix of fry-oil and mineral spirits in a
truck and apparently has been doing it for a while. If it is of any
interest I can either post it here, or...

The e-mail came about when the price of diesel made one of its
frequent jumps in price and since this is practically the home of the
palm oil business I thought about running the pick-up on palm oil.

Unfortunately, normal Thai cooking doesn't have much waste oil
involved. What goes in the pan ends up on your plate. I checked with
some of the fast food places and they all have someone who is buying
their used cooking oil. I ended up pricing the price of palm oil in 20
ltr. tins only to discover that diesel oil was cheaper :-(

I got a laugh over the "oil press" site. the "Chang Fa" motors he
talks about are simply one of God knows how many makers in Asia that
make copies of the old one cylinder Yanmar engines, that Yanmar still
makes. They are literally all over the place over here, powering
everything from fishing boats to garden tractors to home made trucks.

The home made trucks that the guy will sell you a pamphlet on how to
build? Home made trucks are all over N.E. Thailand powered by these
"Chang Fa" type engines. If you are interested here is a site that
shows one http://boingboing.net/2009/08/02/incredible-thai-etan.html

The poster type picture at the top of the site is an advertisement for
a shop that builds the bodies only. It says "Bring in your truck and
we'll fit one of the body styles shown" :-)

John B. Slocomb

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