Newsgroups: sci.environment,sci.energy,sci.energy.hydrogen
From: B.Hamilton@irl.cri.nz (Bruce Hamilton)
Subject: Re: Energy production from non fossil fuel sources
Date: Tue, 02 Jul 1996 17:10:30 GMT

[Article now cross-posted to sci.energy and sci.energy.hydrogen,
with followups back to sci.environment


>>I was reading a discussion about whether or not ethanol requires more
>>use of fossil fuel energy to produce than it delivers.   I have seen
>>lots of discussion of this question but never what was for me a
>>definitive answer.   (Ir Bruce Hamilton or someone like him has already
>>provided the answer and  I've forgotten it, I plead a failing memory.)

I've posted several references to the discussions in various publications,
basically there are several aspects that have to be considered, with the
most important being the actual biomass and the use of the byproducts,
but the current perception seems to be that once all the inputs are
considered for the best crops, it may require less energy. The best
source of background and discussion  are two long monographs in
the 4th Edition of the Kirk Othmer Encyclopedia of Chemical Technology.
The first ( in Volume 13 p925-949 ) is "Hydrogen Energy " which discusses the
current situation with hydrogen, and the second ( in Volume 12 p16-110 )
is " Fuels from Biomass " which discusses many of the aspects. Those
volumes were issued in 1994 so they are fairly current. Note that the
hydrogen monograph covers existing hydrogen production, and the
economics of that. There are no biological hydrogen production systems
currently available that approach the low $ cost of hydrogen from fossil
fuel sources. There may be good environmental reasons to switch, but
the economics are not currently competitive.

I've given up on the Biomass Alliance who post to sci.energy, and who often
claim diverse environmental benefits, but not *once* have responded to my
reference to the recent paper on the potential for increased global carbonyl
pollution from increased biofuel usage that has been highlighted by recent
atmospheric measurements. The possibility of replacing one global pollutant
with another should not be ignored, but they seem to believe that any
potential environmental problems of their favorite shouldn't be discussed.

When considering fuel ethanol from corn, the price of corn can make
huge differences. Chemical Marketing Reporter 13/11/95 p5 reported
that with corn at $3.30 to $3.40/bushel and one bushel typically yielding
2.5 gallons of  ethanol, the feedstock cost alone was $1.32/USgallon.
At that time MTBE was 70-75 cents/US Gallon and methanol 34-35
cents/US Gallons ( but has risen significantly since then due to use as
MTBE feedstock pressure and other demands ). Fuel ethanol receives
both federal and state subsidies. As all alcohols carry oxygen that reduces
the energy content of the fuel, then transportation of the fuel takes a
big hit because you are wasting energy moving useless oxygen around.
There have been huge numbers of studies performed on the economics
some funded by the fossil fuel industry, and some funded by the strong
alcohol and agricultural lobbies. The infamous US Dept of Agriculture
study of  mid 1995 that claimed that corn-based ethanol results in a 24% gain
in energy was derived by providing energy credits for material like gluten
feed co-products - without actually demonstrating the energy was available
or able to be conveniently used. The best claim was that a gallon of
domestically produced ethanol can displace seven gallons of imported oil.  When
examined closely, the claim meant that only one BTU of oil energy was used in
the production of seven BTUs of corn ethanol energy - omitting the rather
significant fact that the majority of the energy used to produce the ethanol
comes from coal - which was conveniently forgotten :-).  There are many
advantages of hydrogen with compared to alcohol ( eg energy density ), and
that is why production from biomass continues to be investigated-

>>This might be a good time for an expert to fill us in on the prospects
>>for hydrogen as a basic fuel, assuming the results discusssed in
>>the Times hold up.

There are several problems for hydrogen if used in an internal combustion
engine as a substitute for gasoline. From the gasoline FAQ,

9.5  Why are hydrogen-powered cars not available?

The Hindenburg.

The technology to operate IC engines on hydrogen has been investigated in
depth since before the turn of the century. One attraction was to
use the hydrogen in airships to fuel the engines instead of venting it.
Hydrogen has a very high flame speed ( 3.24 - 4.40 m/s ), wide flammability
limits ( 4.0 - 75 vol% ), low ignition energy ( 0.017 mJ ), high autoignition
temperature ( 520C ), and flame temperature of 2050 C. Hydrogen has a very
high specific energy ( 120.0 MJ/kg ), making it very desirable as a
transportation fuel.  The problem has been to develop a storage system that
will pass all safety concerns, and yet still be light enough for automotive
use. Although hydrogen can be mixed with oxygen and combusted more
efficiently, most proposals use air [114,119,121-124].

Unfortunately the flame temperature is sufficiently high to dissociate
atmospheric nitrogen and form undesirable NOx emissions. The high flame
speeds mean that ignition timing is at TDC, except when running lean, when
the ignition timing is advanced 10 degrees. The high flame speed, coupled
with a very small quenching distance mean that the flame can sneak past
inlet narrow inlet valve openings and cause backflash. This can be
mitigated by the induction of fine mist of water, which also has the
benefit of increasing thermal efficiency ( although the water lowers the
combustion temperature, the phase change creases voluminous gases that
increase pressure ) and reducing NOx [124]. An alternative technique is
to use direct cylinder induction, which injects hydrogen once the cylinder
has filled with an air charge, and because the volume required is so
large, modern engines have two inlet valves, one for hydrogen and one for
air [124]. The advantage of a wide range of mixture strengths and high
thermal efficiencies are matched by the disadvantages of pre-ignition and
knock unless weak mixtures, clean engines, and cool operation are used.

Interested readers are referred to the group sci.energy.hydrogen and the
" Hydrogen Energy" monograph in the Kirk Othmer Encyclopedia of Chemical
Technology [124], for recent information about this fuel.

[ end extract ]

Of course many of those problems would be overcome *if* the hydrogen
could be burned with the stoichiometric quantity of oxygen, reather than
air - such as from the on-board electrolysis of water - but there are no
current viable methods. As Popular Science once put it ( October 1993,
"The Outlook for Hydrogen" p66-71,111 ), " If the Utopian promise of a
hydrogen economy remains unfulfilled, it's not for a lack of effort ".

The basic problem for hydrogen is the perceived lack of a safe storage
system for mobile transportation. Until that is overcome, it will not
achieve public acceptance. The basic problem for the biomass industry,
is that they can not currently produce hydrogen as cheaply as it can be
produced from fossil fuels, and they have a long way to go....

>If you post that query in sci.energy, you'll be inundated with opinions
>and perhaps some information.

:-) And I've gone and cross-posted to sci.energy.hydrogen as well!

              Bruce Hamilton

Newsgroups: sci.environment,sci.energy,alt.energy.renewable
Subject: Re: Ethanol and Gasoline
From: B.Hamilton@irl.cri.nz (Bruce Hamilton)
Date: Tue, 27 May 1997 08:49:22 +12

In article <5m9td5$8t1@mtinsc05.worldnet.att.net>
 "Steve Spence" <stevespence@worldnet.att.net> writes:

>If you take a multipoint fuel injected automobile (there are after market
>fuel injection units that let you specify flow rates, air/fuel ratio, and
>timing - B&M, Edelbrock, & Holley come to mind), increase the flow rate to
>handle the additional fuel level needed, advance the timing, explain to me
>why a pure (180+ proof) alchohol won't run smoothly. If you wanted to make
>major mods, (increase compression by shaving the deck) power output will be
>greater (and more efficient). And yes, the US has and permits pure
>alchohols. You can get a permit for low production as an individual.

Steve. ..What I posted was..

>> In fact, the vast majority of modern fuel-injected engines can not cope
>>with pure alcohol fuels. The cold start problems do persist
>>with fuel injection. I'd be surprised if the US permits pure alcohols.
>>..... The reality is that
>>*only* possible vehicles designed to cope with the high latent
>>heat of evaporation of alcohol fuels (ie FFVs designed
>>to cope with US "alcohol" fuels ) are specialist designs.
>>The US " alcohol " fuels are not pure alcohols

So, let's take them one at a time:-
>> In fact, the vast majority of modern fuel-injected engines can not cope
>>with pure alcohol fuels.

They can not. What you are suggesting is a wide range of
modifications that will make the vehicle illegal on the road.
If people want to spend large sums for money converting
an engine to run on methanol they will - look at the cost
of a methanol racing engine... but they are not the "vast
majority", they bear little resemblence to the original engine,
and they are not legal on the road.

The reality is that such modifications are not acceptable for
emissions reasons, they may be practical for drag racing,
but point me to any reference to a pure methanol-powered
current ICV car that passes the current FTP emissions for
road use that is not a FFV.

>> The cold start problems do persist with fuel injection.

The high latent heat of methanol means that cold start
problems with pure methanol are a major problem. Several
techniques have been suggested to get around it. Including
various heating devices to vaporise the fuel, various small
separate tanks of a volatile fuel just for cold starts, but the
most common involve adding a volatile component - either a
hydrocarbon fraction ( as in the US "Methanol" retailed
for road use ) - which also addresses some of the safety
concerns, or converting the methanol to the more volatile
dimethylether using an on-board reactor.

>>> I'd be surprised if the US permits pure alcohols.
>>..... The US " alcohol " fuels are not pure alcohols

The " methanol" fuel sold for road use is actually a
methanol-hydrocarbon blend designed to provide cold
starting and cover the safety issues( explosiveness and
visibility of flame ). The US EPA also prohibits more than
0.3% of methanol in gasoline, all other uses have to
obtain a waiver. There are also limits for ethanol-gasoline
blends. The "methanol" fuel used on the road in the USA is not
pure methanol - this means the environmental advantages
are diminished when compared to pure alcohol, as hydrocarbon
emssions are increasedcompared to the alcohol.

You can talk about making expensive modification as much as
you wish, but the reality is that only the limited number of
specially-designed FFVs can run on alcohol fuels, and some
of those may not even run on pure alcohols.

           Bruce Hamilton