Biodiesel vs ethanol

[laurent_caen]

bonsoir a tous
a question tears me: what is, in a country with a temperate climate like France, the most ecological solution between the oilseed and ethanol, a vast question I admit:
amount of fuel produced per hectare
quantity and toxicity of widespread pesticides
amount of water consumed
energy consumed in the manufacture of fuel
conso of a car in oil / ethanol (energetic rendemt)
% of oil or ethanol possible to incorporate ...
In short, I would like to do a little inventory to see more clearly and I invite you to share your knowledge to take advantage of all pr advance the schmilblick
thank you in advance

[laurent_caen]

dsl I just realized that I did not put my subject in the right topic I apologize
mea culpa

[Woodcutter]

bonsoir a tous
a question tears me: what is, in a country with a temperate climate like France, the most ecological solution between the oilseed and ethanol, a vast question I admit:

Not simple your question ...

amount of fuel produced per hectare

CNAM data (2006) Beets => 70 to 75 t / ha i.e. 6 to 7 m3 / ha of ethanol, to be compared with sugar cane => 80 to 90 t / ha or 7 to 8 m3 / ha of ethanol, or corn => 7,2 to 8,5 t / ha or 2,9 to 3,4 m3 / ha of ethanol.
Rapeseed => 3 t of seeds / ha i.e. 0,8 m3 to 1 m3 HVP / ha (same as sunflower) and 2,2 t of oil cake to compare with Guinean oil palm => 3,5 m3 to 5 m3 / ha HVP

ADEME data (2002):
Rapeseed => 3,34 t of seeds / ha or 1,37 t HVP / ha and Sunflower => 2,24 t of seeds / ha or 1,06 t HVP / ha
Beets => 5,8 t ethanol / ha and Wheat 2,55 t ethanol / ha

quantity and toxicity of widespread pesticides

J'sépô ...
But apparently, according to my oil producer, it is impossible to do without pesticides for rapeseed, otherwise the flowers are not fertilized and therefore there is inevitably no seeds ...

amount of water consumed

For the "sugar" sector, I don't know, but apparently sunflower and rapeseed do not require water, whereas corn does.

energy consumed in the manufacture of fuel

Oil pressing: 5% of production (CIRAD)

Energy balance expressed in MJ used by MJ produced (ADEME):
- HVP Rapeseed and Sunflower 0,214 and 0,183
- 0,334 and 0,316 EMHVs to compare with 1,09 diesel
- Ethanol (betterbebe or wheat) 0,49 compared to 1,15 gasoline

conso of a car in oil / ethanol (energetic rendemt)

Clearly, diesel (oil or oil ester) outweighs ethanol, which in turn induces overconsumption p / r to petrol.
Source CIRAD: PCI ethanol: 26 900 kJ / kg (d = 0,79), PCI coconut oil 39 500 kJ / kg (d = 0,92) while petroleum products are at 44 000.
On the other hand, ethanol has a higher octane number (106) which can be exploited by dedicated engines, with higher compression ratio or VCR engines.
However, the MON index (useful for high load situations) is no longer as interesting (around 92), the difference between RON and MON being larger than for petrol.

[for clues, there are other numbers ... who to trust?
CNAM source: octane number 120 / 99]

% of oil or ethanol possible to incorporate ...

Ben ... it depends ! If you speak of esters, apparently it is 30% without any modifications and with manufacturer's warranty but it would surely be possible to do more. With the HVP, it's more delicate.
Ethanol is 100%, but with dedicated "Flex-fuel" models (beyond 5% incorporation) but with particular cold starting problems, which do not exist at 85% (E85).

[jlvx]

Has our National Lumberjack also found the yield figures for Miscantium (or "elephant grass") for ethanol production?
We do not seem to consider the production of bio fuels, that from "classic" agriculture, that is to say in open fields, from where more or less strong needs in water and in "chemical" inputs, not or little in soilless culture, or greenhouses or whatever it is called.
What do you think of this production "cycle":
1) stage: methanisation by digester of "waste water" (if urban or peri-urban location) or of various animal "effluents" (if rural environment, breeding region)
2) methane will be used as energy for the "factories" producing bio diesel or gasoline, either for heating or for drying.
In addition the dry matter from the previous recycling will be used as a nutrient for crops
3) cultivation "in the factory" or "in greenhouses" of plants, certainly not GMO, but the best species according to the yield / number of annual harvests criterion, either of rapeseed, or of sunflower, or of jathropa (?) Etc ( there are enough INRA or equivalent in the world to already have several alternatives)
When I say "greenhouse", I am thinking of several stages of cultivation of the plant which will have been selected, in order to obtain at least 5 times more tonnage per m2 on the ground (a Japanese "mad" gardener grows lettuce practically on "walls", it takes 10 times less floor space);
nutrient supply = recycling, energy supply itou, possibly supplemented by solar / wind / geothermal according to local possibilities, water supply = drip or spraying, or..ne for some species of sunflower.
4) cold pressing, press also fed by one of the ENR, production of HVP.
5) recovery of cakes sold to farmers and / or after drying reuse of biomass remaining in heating or other recycling
There it is complicated is that the pure HVP, even filtered "tight" is not 100% usable in a diesel even "old";
That said, bi-fuel systems exist in Germany, needed for cold starts and first kms;
Or, processes of transesterification, but a little more polluting;

Another solution, the algae, fed with CO2, what is missing is a reasonably short cycle and efficient in the recycling of CO2 + algae pools + oil harvesting / recovery

And last but our least, the "direct" production of bio diesel, and no longer HVP thanks to bacteria (see work of the University of Münster), basically the bacteria in question (non-union) making it possible to produce the necessary methanol converting HVP into diesel;

We dream , ?

No, I do not think so, just have the patience to wait for the passage of the research to the setting in production, which, except blocking of the tankers (hypothesis of school ) should take at best 5 years, at most 10 years;

Basically, it should be oil companies who invest in this sector for diversification, and "recycling" of a (small) part of their profits.

[Woodcutter]

Has our National Lumberjack also found the yield figures for Miscantium (or "elephant grass") for ethanol production? [...]

No, I did not know it was Miscanthus (which?) That was studied by INRA ...
Maybe it's on the Net?

EDIT: found in an INRA document => 15 to 18 t / DM / ha / year for Miscanthus (no specification of the species) but recoverable only in the event of use of all the biomass (see reflection below on the "lignocelluslosic" route) ...

Otherwise, as far as the "methanol path" is concerned, the future obviously consists of using the whole plant.

Finally, for "multi-storey" crops, quid of the main and necessary input: solar energy?

For the HVP, I am not following you, it is rather the opposite: usable with dual fuel in an "old" Diesel (before the "common rail") at 100%, but much more difficult in modern generations.

EDIT 2: while rummaging a little, I found your messages on Oléocène ...
You can find all the info you miss ... why two post-quasi-similar but different?