aahala wrote:About one in eight bushels of US corn production is used in order to
produce ethanol equal to about 2-3% of gasoline consumption. The
math isn't very encouraging.
The price isn't much better. For the last 20 years, the wholesale price
of pure ethanol has been higher than the wholesale price of gasoline
about 90% of the time. This is on a gallon to gallon basis. Adjusted for
mileage, $1.75 ethanol equals about $2.60 gasoline.
Alfred Tennyson wrote:We are not now that strength which in old days
Moved earth and heaven, that which we are, we are;
One equal temper of heroic hearts,
Made weak by time and fate, but strong in will
To strive, to seek, to find, and not to yield.
jmacdaddio wrote: fitter not fatter Americans makes health care costs go down and leaves us more money for military campaigns against corn-producing countries.
GWB just happened to mention corn-based ethanol in his address last Tuesday .. conicidence?
Caoimhan wrote:There are some good plusses with methanol, and some minuses, too.
No solution is perfect, but methanol production seems like a good idea on the whole.
I wonder how the CO2&Water method of methanol production compares to the electrolysis method of producing H2, in terms of electicity use. If the EREOI is much better for methanol, I can't see a reason to use H2.
Caoimhan wrote:One good thing about the methanol, is that it really won't require much in infrastructure changeover. Methanol can be mixed immediately into gasoline blends, even with ethanol, I believe.
Caoimhan wrote:At first, while NG is still relatively cheap, I'm sure that it will continue to be the main feedstock for methanol. But as NG gets higher in price, the CO2/H2O method may be able to scale up. That's the big question... how fast can non-NG methanol production scale and to what degree?
The data of the described synthesis variant shows that upon a biomass
input of 2 t/h wood (from forestry), an electric power consumption of ca. 5 MWe at a produced methanol rate of 1.2 t/h is necessary.
....
However, upon a wood input of 2 t/h, an electrical power demand of nearly 13 MW, leading to a methanol output of ca. 2.2 t/h, is required.
....
The separation of CO2 from flue gases ....The whole energy chain including the necessary fossil primary energy use is shown on Figure 4. Up to the methanol supply, the energetic efficiency rate is ca. 46 % [10]. However, this efficiency rate can be considerably increased (by over 50 %) if instead of conventional methods (CO2 recovery with alkanolamines) future power plant technologies (coal gasification and CO2 separation before incineration), which minimize the energy rate of the CO2 separation process, are used....
If atmospheric CO2 is the source product for the methanol synthesis... the total energy balance of this process is significantly lower, i.e. ca. 38 %
Caoimhan wrote:The assumptions about H2 in that review assume that H2 would have to be transported either compressed (CHG), or liquified (LH).
It seems very likely to me, however, that CHG and LH will both be abandoned as Hydrogen storage, as metal-hydride storage is perfected. See
THIS PAGE for info about it.
If hydrogen can be produced without fossil fuels cheaper than methanol, this seems to be the best route to take.
I'm not sure how the math adds up.
whereagles wrote:wait a minute... isn't methanol rather.. ahem.. toxic?
Wikipedia wrote:methanol is toxic (this risk has been hugely overstated; methanol poisoning invariably results from drinking illegal liquor; methanol volatilizes and biogrades rapidly in the environment.)
backstop wrote:Caoimhan -
"The Methanol-Cycle" - Sustainable Supply of Liquid Fuels
The wide range of cogent objections to hydrogen as transport fuel seem to me to mitigate strongly in favour of methanol, particularly in view of the storage issue.
The metal hydrates storage plan is not only a lab-option at present, and shows no promise of being scaleable to the global tanker fleet capacity required, it also demands substantial energy inputs both for hydrogen insertion and extraction.
backstop wrote:The still greater range of profound objections to unsustainable nuclear power would be exacerbated by the notion of building additional nuclear to generate methanol,
given the massive loss of primary energy involved. (The report above defines that loss from Hydro-power methanol as being around 56%).
backstop wrote:Quite what the projected full-term full-spectrum £-costs of Nuclear methanol would be remains to be seen, but the fact that the nuclear lobby has never yet promoted this option doesn't add to its credibility.
backstop wrote:Thus my expectation of whatever advances in transport fuels can be achieved globally rest on the spectrum of benefits of sustainable reforestation of non-arable land for methanol feedstock,
not least because even at this stage of development its costs are looking competitive with fossil oil.
backstop wrote:The still greater range of profound objections to unsustainable nuclear power would be exacerbated by the notion of building additional nuclear to generate methanol,
given the massive loss of primary energy involved. (The report above defines that loss from Hydro-power methanol as being around 56%).
backstop wrote:Quite what the projected full-term full-spectrum £-costs of Nuclear methanol would be remains to be seen, but the fact that the nuclear lobby has never yet promoted this option doesn't add to its credibility.
backstop wrote:the fact that the nuclear lobby has never yet promoted this option doesn't add to its credibility.
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