[Éthanol]

[GillesH38]

Certes, mais je me plaçais déjà dans l'époque pas si lointaine où il faudra TOUT faire avec des renouvelables....

[th]

Pour produire du bio ethanol, il faut de l'energie.
Pourquoi pas utiliser du charbon, ce sont dit des américains, interessés par les detaxes sur les bio carburants...

Resultat :

Late last year in Goldfield, Iowa, a refinery began pumping out a stream of ethanol, which supporters call the clean, renewable fuel of the future.

There's just one twist: The plant is burning 300 tons of coal a day to turn corn into ethanol - the first US plant of its kind to use coal instead of cleaner natural gas.

la suite ici http://www.csmonitor.com/2006/0323/p01s01-sten.html

[energy_isere]

Pour produire du bio ethanol, il faut de l'energie.
Pourquoi pas utiliser du charbon, ce sont dit des américains, interessés par les detaxes sur les bio carburants...

Resultat :

Late last year in Goldfield, Iowa, a refinery began pumping out a stream of ethanol, which supporters call the clean, renewable fuel of the future.

There's just one twist: The plant is burning 300 tons of coal a day to turn corn into ethanol - the first US plant of its kind to use coal instead of cleaner natural gas.

la suite ici http://www.csmonitor.com/2006/0323/p01s01-sten.html

oui, je l'avais lu ce matin, le probléme c'est que les 300 tonnes de charbon, on ne sait pas les comparer energétiquement avec la production d' ethanol (chiffre non cité) qui consomment ces 300 tonnes de charbon.
Donc l' article perd de tout son interet. Dommage.

[th]

Donc l' article perd de tout son interet. Dommage.

Il reste interessant sur le plan qualitatif. Il montre bien comment la volonté politique de favoriser les bio-ethanol pour des raisons environnementales, peut être battue en brêche si aucune regulation n'est faite sur le moyen de produire cet ethanol.

[Tiennel]

oui, je l'avais lu ce matin, le probléme c'est que les 300 tonnes de charbon, on ne sait pas les comparer energétiquement avec la production d' ethanol (chiffre non cité) qui consomment ces 300 tonnes de charbon.
Donc l' article perd de tout son interet. Dommage.

J'ai trouvé cette page qui parle de 50 millions de gallons par an.
Avec une hypothèse de fonctionnement de 250 jours par an, cela fait 50m / 250 *3,785 = 750 000 litres d'éthanol par jour

En gros, 2 kg de charbon pour 1 kg d'éthanol. Pas terrible.

[energy_isere]

oui, je l'avais lu ce matin, le probléme c'est que les 300 tonnes de charbon, on ne sait pas les comparer energétiquement avec la production d' ethanol (chiffre non cité) qui consomment ces 300 tonnes de charbon.
Donc l' article perd de tout son interet. Dommage.

J'ai trouvé cette page qui parle de 50 millions de gallons par an.
Avec une hypothèse de fonctionnement de 250 jours par an, cela fait 50m / 250 *3,785 = 750 000 litres d'éthanol par jour

En gros, 2 kg de charbon pour 1 kg d'éthanol. Pas terrible.

Tiennel, t'es un as !

en effet dans ton lien :

Central Iowa Renewable Energy LLC (Corn LP) - Goldfield Iowa. Plant under constuction, to produce 50 million gallons per year of ethanol.

donc 2 kg de charbon pour 1 kg d'éthanol, c'est une HORREUR ECOLOGIQUE pour le bilan CO2.

c'est juste bon pour faire plaisir à Bush pour importer un peu moins de pétrole d' Arabie Saoudite.

Mais c'est sans doute trés bon pour le business local dans l ' IOWA.

[energy_isere]

pour enfoncer le clou un peu plus sur la "mauvaise" utilisation du charbon dans le process de fabrication de l' éthanol fait à partir du grain de Mais (corn) :

L'auteur propose plutot le développement de l' éthanol à partir de la biomasse (cellulose) plutot qu' à partir du grain.

http://www.futurepundit.com/archives/003330.html

Coal Corn Ethanol Plants Seen As Emerging Trend

March 25, 2006

Long time readers know I'm not a fan of biomass energy. Well, here's yet another reason to be underwhelmed by the prospect of corn ethanol. Can you say "Defeating the purpose"? Sure!

Late last year in Goldfield, Iowa, a refinery began pumping out a stream of ethanol, which supporters call the clean, renewable fuel of the future.

There's just one twist: The plant is burning 300 tons of coal a day to turn corn into ethanol - the first US plant of its kind to use coal instead of cleaner natural gas.

An hour south of Goldfield, another coal-fired ethanol plant is under construction in Nevada, Iowa. At least three other such refineries are being built in Montana, North Dakota, and Minnesota.

The trend, which is expected to continue, has left even some ethanol boosters scratching their heads. Should coal become a standard for 30 to 40 ethanol plants under construction - and 150 others on the drawing boards - it would undermine the environmental reasoning for switching to ethanol in the first place, environmentalists say.

US natural gas production is declining. Coal is a much cheaper source of heat energy - at least in the United States. But burning the coal will release particulates, mercury, and other pollutants into the atmosphere. Even if you are thrilled at the prospect of a warm Antarctica for your own ocean front house (with way more coastline than Florida currently has) the other pollutants are not good. Plus, the corn takes more land for agriculture.

Bottom line: federal corn ethanol subsidies are now going to increase carbon dioxide emissions as well as assorted pollutants. Your tax dollars at work. The article reports that even some existing plants may switch from natural gas to coal since the money savings from the switch are so large.

Recently Dan Kammen and Alex Farrell at UC Berkeley claimed that a switch to corn ethanol would slightly reduce greenhouse gas production.

Despite the uncertainty, it appears that ethanol made from corn is a little better - maybe 10 or 15 percent - than gasoline in terms of greenhouse gas production, he said.

"The people who are saying ethanol is bad are just plain wrong," he said. "But it isn't a huge victory - you wouldn't go out and rebuild our economy around corn-based ethanol."

Just plain wrong? I think he spoke too soon. My guess is these guys used an assumption of natural gas to run the corn ethanol plants. With coal producing maybe twice as much carbon dioxide (according to the first article above) corn ethanol is probably worse than gasoline for net carbon dioxide emissions. Though the Christian Science Monitor article suggests the Berkeley people did consider coal for making corn. So maybe the press release leaves out an important qualifier that was in the original paper.

But I agree with the Berkeley guys that when cellulosic technologies are perfected (and venture capital money is funding efforts along those lines) then switchback grass might be able to provide ethanol with much less carbon dioxide emitted by the processing plants.

The transition would be worth it, the authors point out, if the ethanol is produced not from corn but from woody, fibrous plants: cellulose.

"Ethanol can be, if it's made the right way with cellulosic technology, a really good fuel for the United States," said Farrell, an assistant professor of energy and resources. "At the moment, cellulosic technology is just too expensive. If that changes - and the technology is developing rapidly - then we might see cellulosic technology enter the commercial market within five years."

Cellulosic technology refers to the use of bacteria to convert the hard, fibrous content of plants - cellulose and lignin - into starches that can be fermented by other bacteria to produce ethanol. Farrell said that two good sources of fibrous plant material are switchgrass and willow trees, though any material, from farm waste to specially grown crops or trees, would work. One estimate is that there are a billion tons of currently unused waste available for ethanol production in the United States.

Any analysis of biomass energy ought to build into it the assumption that the plant operators will use coal. Either that or they have to show that the biomass itself can provide any heat energy needed to operate the plant and do so at a competitive price.

j'ai trouvé l' article grace à http://www.321energy.com/ dont je vous recommande la lecture réguliére.

[super_newbie_pro]

Bonjour

Pardonnez ma question dans ce topic, mais au vu de toutes les oppositions contre les projets écologiques, les emmerdes qu'ont les inventeurs, les pressions des pouvoirs publiques, la mauvaise foi de certains organismes, la pression des lobbies pétroliers...

Auriez-vous une citation ou une phrase qui résume bien l'échec dans la plupart des cas dans le domaine de l'écologie innovant ?

[th]

Auriez-vous une citation ou une phrase qui résume bien l'échec dans la plupart des cas dans le domaine de l'écologie innovant ?

Ma signature ?

[toto]

Pour integrer il faut savoir deriver.

[energy_isere]

dans l'article du New York Times ci dessous on explique l'investissement dans l' éthanol, en particulier par de riches milliardaires comme Bill Gates (Microsoft) ou Branson (Virgin) ou Khosla (Sun Microsystem)

http://www.iht.com/articles/2006/03/26/ ... iofuel.php

[energy_isere]

voici encore quelques commentaires au sujet de l'utilisation du charbon dans la filiére ethanol des USA à partir des grains de Mais, pour faire suite à la discussion de quelques messages au dessus : Ethanol and coal


http://gristmill.grist.org/story/2006/3/27/105942/766

Ethanol and coal

Posted by Tom Philpott at 11:12 AM on 27 Mar 2006
David's post about ethanol and coal inspired me to do a bit of research on just how much coal goes into producing G.W. Bush's favorite "renewable," "clean-burning" fuel source.

What I found is ... disturbing.


First, some background. Before you can distill corn into fuel, you have to crush it. There are two ways to do so: wet milling and dry milling.
According to this USDA document, dry milling accounts for about two-thirds of ethanol production, wet milling the rest. Traditionally, dry-milling relies on natural gas for power, while wet milling leans on natural gas and coal in roughly equal proportions.

In addition to traditionally not using coal, dry milling is a bit more energy-efficient than wet milling, which according to this Energy Star document (PDF) ranks as "the most energy intensive industry within the [food-processing sector], using 15% of the energy in the entire food industry."

Thus, if corn-based ethanol must exist, dry-milled ethanol beats wet-milled. (Note: I think corn-based ethanol is an environmental and economic disaster no matter how it's milled.)

Here's where we get to the disturbing part of the Christian Science Monitor piece David points us to. According to CSM (via Alternet), the new coal-burning plant in question uses dry-milling. The article states:

<<The Goldfield refinery, and the other four coal-fired ethanol plants under construction are called "dry mill" operations, because of the process they use. The industry has in the past used coal in a few much larger "wet mill" operations that produce ethanol and a raft of other products. But dry mills are the wave of the future, industry experts say. It's their shift to coal that's causing the concern. [Emphasis added.]>>

The article claims high natural-gas prices are inspiring dry-millers to shift to coal. "It just made great economic sense to use coal," one newly launched dry-mill ethanol plant manager tells CSM.

Since two-thirds of ethanol plants are dry millers currently relying on natural gas, that's a disturbing statement. So is CSM's claim that industry buzz about "retrofitting existing refineries for coal is growing."

Think it would "just [make] great economic sense to use coal" for dry-milled ethanol if David ruled the world and he imposed a stringent carbon tax?

Of course, if I ruled the world, the point would be moot: Ethanol and industrial corn would cease to exist -- and the Midwest would be a magnet for foodies indulging in some of the best vegetables and grass-fed meats available anywhere.

ca confirme que l' utilisation du charbon dans la filiére éthanol est une hérésie du point de vue du rejet de CO2.

[energy_isere]

le cout de l' éthanol s' envole aux USA à cause de modification dans la composition de l'essence vendue aux USA qui va interdire l' additif MTBE dans leur essence, et qui va étre remplacé par l' éthanol.

http://www.fortwayne.com/mld/fortwayne/ ... 244167.htm

Demand for ethanol grows, prices surge

Posted on Sun, Apr. 02, 2006
Associated Press

SHADELAND – Growing demand for ethanol has boosted prices for the corn-based fuel additive, worrying ethanol supporters just as they’re making inroads getting motorists interested in the alternative fuel.

Greg Boesch, who owns Fred’s Mini Mart in Shadeland, said that when he began selling a fuel that contains a high percentage of ethanol, it was between 30 cents and 40 cents a gallon cheaper than gasoline.

Now, he’s only able to keep the price of both products at $2.57 a gallon by losing money on sales of E85, a blend composed of 85 percent ethanol and 15 percent gasoline.

“I had been telling my customers that it was going to be cheaper. Now, all of a sudden, I’m having to back down,” Boesch told the Journal and Courier of Lafayette.

Boesch’s station a few miles southwest of Lafayette is one of 23 gas stations in Indiana that sell the fuel. State officials hopes to raise that number to 40 by the end of the year, and federal officials want to keep them supplied. Lassus Brothers Oil Inc. sells E85 at its gas station at Coldwater and Wallen roads.

But last week, representatives of the energy industry told the U.S. Senate Environment and Public Works Committee that an unprecedented high demand for ethanol will likely drive the price of gasoline up this summer.

Guy Caruso, who heads the U.S. Energy Department’s statistical division, estimates that 130,000 barrels per day of extra ethanol will be needed beginning May 5 – an amount equal to almost 50 percent of current output.

Wholesale prices for ethanol have surged to about $2.75 a gallon, or about 50 cents a gallon higher than usual. Meanwhile, the average retail price of gasoline in the United States is $2.50 a gallon – the highest level since October.

Some analysts say gasoline prices might reach $3 a gallon by summer.

The new demand for ethanol stems largely from the decision of many states to stop allowing methyl tertiary butyl ether as an additive in gasoline. MTBE, which can contaminate ground water, composes about 10 percent of every gallon of gasoline with which it is blended.

Community and government leaders across the nation hope to eventually replace the additive with ethanol, a grain alcohol many consider a renewable fuel.

Nationwide, 33 ethanol plants are being built and six of them are in Indiana.

Belinda Puetz, director of marketing for the Indiana Corn Marketing Council, said she doesn’t doubt that once more ethanol is produced, the price of the additive will fall.

“We are kind of in that awkward stage where the demand is greater than the supply,” she said. “We should have some of that production available in 12 to 18 months.”

[energy_isere]

un long article sur l 'ethanol au Brésil dans :
http://www.nytimes.com/2006/04/10/world ... ref=slogin

With Big Boost From Sugar Cane, Brazil Is Satisfying Its Fuel Needs

j'ai extrait le morceau suivant qui compare le rendement energétique de cet ethanol produit à partir de la canne au Brésil, et celui produit à partir du Mais aux USA :

Ethanol can be made through the fermentation of many natural substances, but sugar cane offers advantages over others, like corn. For each unit of energy expended to turn cane into ethanol, 8.3 times as much energy is created, compared with a maximum of 1.3 times for corn, according to scientists at the Center for Sugarcane Technology here and other Brazilian research institutes.

"There's no reason why we shouldn't be able to improve that ratio to 10 to 1," said Suani Teixeira Coelho, director of the National Center for Biomass at the University of São Paulo. "It's no miracle. Our energy balance is so favorable not just because we have high yields, but also because we don't use any fossil fuels to process the cane, which is not the case with corn."

ce qui confirme que l 'éthanol issu de la filiére Mais aux USA est à peine rentable, comme on l'a déja analysé dans des posts plus haut.

Il y a aussi le fait que les coupeurs de cannes au Brésil sont payés une misére. (ce qui a été dit sur l' émission Envoyé spécial "Le pétrole vert" la semaine derniére)

[sceptique]

energy_isere Tiennel
oui, je l'avais lu ce matin, le probléme c'est que les 300 tonnes de charbon, on ne sait pas les comparer energétiquement avec la production d' ethanol (chiffre non cité) qui consomment ces 300 tonnes de charbon.
Donc l' article perd de tout son interet. Dommage.
J'ai trouvé cette page qui parle de 50 millions de gallons par an.
Avec une hypothèse de fonctionnement de 250 jours par an, cela fait 50m / 250 *3,785 = 750 000 litres d'éthanol par jour
En gros, 2 kg de charbon pour 1 kg d'éthanol. Pas terrible.

Tiennel, t'es un as !

en effet dans ton lien : Central Iowa Renewable Energy LLC (Corn LP) - Goldfield Iowa. Plant under constuction, to produce 50 million gallons per year of ethanol.

donc 2 kg de charbon pour 1 kg d'éthanol, c'est une HORREUR ECOLOGIQUE pour le bilan CO2.

c'est juste bon pour faire plaisir à Bush pour importer un peu moins de pétrole d' Arabie Saoudite.

Mais c'est sans doute trés bon pour le business local dans l ' IOWA.

Désolé de jouer aux rabats-joie mais tiennel a trébuché au dernier calcul :
750 000 litres ethanol pour 300 000 kg charbon donne
2.5 litres ethanol pour 1 kg charbon.
Cependant cela reste encore une HORREUR ECOLOGIQUE pour le bilan CO2, sauf en cas de séquestration
PS : toujours des pb de citation ...