Talk:Cellulosic ethanol

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--Alex 08:27, 17 July 2006 (UTC)

The intro section should discuss why cellulosic ethanol plants are not being built, and why the corn based plants are currently in favor.

--Chiefio

Contents

[edit] 80% less greenhouse gas?

Actually, cellulosic ethanol produces 26.4% of the energy of gasoline and 25% of the Carbon Dioxide. So, if you extrapolate to a cost per absolute energy, cellulosic ethanol produces 94.5% of the greenhouse gas of gasoline. Perhaps someone can find a source to substantiate this. Swakeman (talk) 23:54, 24 February 2008 (UTC)

[edit] Cellanol is not a common term

I'd also note that "cellanol" smells like someone's proprietary name to me. A Google search yields 154 references, many on the top page in French. I've been involved in alternative fuels for at least 30 years and never heard the term before. The word "cellanol" needs to go, unless, of course, the goal of wiki is to coin terms and create new usages... 4.246.237.161 05:39, 25 August 2007 (UTC)

I googled it and I concur, it's uncommon at best, and may be a trademarked term, or used more in a non-English speaking country. Many of those 154 references were copies or foreign translations of the same few passages of text. -Agyle 07:05, 25 August 2007 (UTC)

[edit] Celunol/Cellunol

I did some search on Google recently and the term celunol/cellunol begin to be a bit more common --Sd-100 (talk) 19:38, 7 June 2008 (UTC)

[edit] Economic importance

"Cellulose is present in every plant: straw, grass, wood. Most of these "bio-mass" products are currently discarded"

Really? Aren't these products usually composted or somehow used for soil maintenance? Where are they discarded? Do farmers take them offsite to some kind of landfill? I find this claim extremely hard to believe. Would it be sustainable to remove all plant matter from farms and make ethanol with it? ErikHaugen 19:01, 7 June 2006 (UTC)
Good point. When biomass is left at the place of harvest, the nutrients might not be used optimally, and the energy content is hardly used at all. However that doesn't mean that they are useless, as it might seem from the use of the word discarded. --Alf 18:15, 12 June 2006 (UTC)
Disregard farming: think about the forests which are littered with wood droppings and other woody stuff from wind storms and natural causes. This has to be constantly cleaned up or brought to stump dumps and contains huge amounts of cellulose, which could be converted into ethanol. There are tons of this and it has a negative cost: they pay you now to take it away! I don't think it's a good point at all! Rrrrprrrr (talk) 23:45, 4 February 2008 (UTC)
Plants get and spread diseases just like humans (or much like humans, anyway). If you leave a bunch of rotting plant matter on your fields you'll reduce your yields. Here in California we have a huge amount of biomass which must be destroyed. Each year, farmers in the central valley burn their rice fields after harvest to sterilize the soil so they can get the best harvest next year. Burning rice fields is nasty; rice stalks have small fibers in them like asbestos that burning releases into the air. The practice is being phased out under state law, but replacement technologies are still pretty expensive. Rice farmers would LOVE to get rid of their waste mass if they could get someone to haul it off economically. There's a huge cellulose ethanol plant that they want to build in hopes that cellulose conversion will become economical. Anyway, I've never heard of anyone trying to compost ag waste. The scale of such an endeavor just boggles the mind. --Markspace 06:19, 9 July 2006 (UTC)

There are studies in the literature that show a very good correlation between burning of rice straw in the fields and emergency admissions of children with asthma. If pyrolysis is used, a byproduct is biochar, which can be used as fertilizer: it improves soil structure and water retention, and contains most of the fertilizer components originally in the waste, with the exception of nitrogen.

At present, the problem with the biochemical conversion of plant material to ethanol is that the yield is only around 25%, for practical processes (in the lab, people have gone up to 60%). So, there is still a lot of waste. Another problem is the long residence times that are required, which means that the reactors are very large.

From what I know about organic agriculture, ag waste is composted in conjuction with manure. It also serves as a bedding in traditional animal raising methods, and, as such, it is composted when the manure is composted. I wouldn't call regualar ag waste like straw 'discarted' either, as it serves many purposes. In fact, I wouldn't even call it 'waste', but 'byproduct'. --Hanns-Andre Pitot 12:20, 15 August 2006 (UTC)

Questions: "In July, 2006, according to the Boston Globe, the production cost of cellulosic ethanol was approximately $2.25." $2.25/what? gallon? liter? BTU? Cup? —The preceding unsigned comment was added by 68.181.226.31 (talk • contribs) 20:09, July 29, 2006 (UTC)

A presentation by Dr MAthew Roberts of Ohio State University at the AAEA Annual Meeting, 24 July '06, referenced "~5.50/gal" cost of ethanol from Cellulose.

[edit] Soil conservation requirements

As of early December, 2007, the article appears to recommend corn stover, bagasse and other agricultural residue as source material. In many settings that is unrealistic. Mixing plant residues into the soil is essential to maintain tilth and restrain erosion. In U.S. corn-growing areas, it has been estimated that failure to maintain tilth with stover would lead to a tenfold increase in erosion and exhaust native topsoil in 10-30 years. Practical plans for cellulosic alcohol must take into account soil conservation requirements, or else they will fail to provide sustainable production.

[edit] Energy gain of cellulosic ethanol appears to be unrealistic

All references that I have found claim that production of cellulosic ethanol is far more energy efficient than production of corn ethanol. Since the production of cellulosic ethanol requires all of the elements of corn ethanol production (except converting cellulose to suger instead of starch to sugar) it must require about the same energy not less. According to a science mag [1] article only about 5% of the input energy from corn alcohol comes from petroleum (the rest from coal and natural gas) so the 5% must be for cultivation and hauling and the other 95% for processing at the ethanol plant. The only obvious improvement is in the 5% so how can cellulosic ethanol be significantly more energy efficient than corn ethanol? Dan Pangburn 02:23, 23 February 2007 (UTC)

I don't know the numbers, but the idea that growing the corn crop takes a tiny fraction of the energy needed to distill the alcohol seems dubious. Fuel for farm machinery, materials (natural gas?) for fertilizer and other agrichemicals, etc. The corn plants produce much more cellulose than starch, so if it can be used, there's a much larger return for the same investment.
—wwoods 16:03, 24 February 2007 (UTC)
It also depends on the biomass used. For example, you can use wood chips from lumbermills; this byproduct does not have the cost of corn growth. You could also use energy crops other than corn, like switchgrass; since this plant is perenial you don't have to sow it every year, and it also requires less fertilizer than corn. These may be some of the reasons that cellulosic ethanol is more energy efficient than corn ethanol. I think that the distillation process itself uses less energy but don't know much about that ... Cadors 20:27, 16 April 2007 (UTC)
"so the 5% must be for cultivation and hauling and the other 95% for processing at the ethanol plant." I'm not sure about the logic of this statement. Even for cellulosic ethanol derived from corn, the yield per acre is higher than for ethanol production using just the kernels, so the energy input for cultivation is lower on a per gallon basis. In most parts of the US, corn growth is very fertilizer intensive, relying on large amounts of ammonia generated with natural gas. As suggested above, _potential_ energy yields for cellulosic ethanol are often calculated based on crops that require much less energy for cultivation as a consequence of reduced fertilizer/water use and higher biomass yields per acre. A2a2a2 01:21, 23 July 2007 (UTC)
Indeed, the Science study cited (now here) used switchgrass for cellulosic ethanol, in comparison to corn for conventional ethanol. I'd say more, but this is supposed to be for discussing the article, not the topic of the article. :-) Though this may suggest some areas for expansion in the article. -Agyle 00:55, 20 August 2007 (UTC)

[edit] Unfounded claim?

In the following paragraph:

"BlueFire Ethanol Fuels utilizes post-sorted MSW, rice and wheat straws, wood waste and other agricultural residues and implements significant proprietary improvements to concentrated acid hydrolysis. The Technology is unique in that, for the first time, it enables widely available cellulosic materials, or more commonly, biomass, to be converted into sugar in an economically viable manner, thereby providing an inexpensive raw material for fermentation or chemical conversion into any of a hundred different specialty and/or commodity chemicals. In February of 2007, BlueFire Ethanol was among 6 companies that received a grant from the US Department of Energy for $40M to promote development of cellulosic ethanol refineries"


This sounds like self-promotion. There are no references cited to support this claim of uniqueness or economic viability.

69.250.53.6 05:57, 8 November 2007 (UTC)

[edit] Sourcing

I don't understand why production of cellulosic ethanol should produce any greenhouse gases, since all of the carbon released by burning it was taken out of the atmosphere by the initial plant growth. There must be some assumptions that production equipment will be using energy from non-ethanol sources? These kinds of assumptions should be explained. The reference given is to an environmental advocacy group, which does not seem terribly reliable, and the details of and sources for this claim are not explained.

The section about the 2006 U.S. Senate hearing is currently referenced to a blog, which does not seem like a reliable source. -- Beland 16:07, 8 November 2007 (UTC)


GHG's aren't only emitted from burning carbon-based fuels, the farming itself releases amounts of CO2 that are non-negligible and is otherwise stored in the ground. The question of whether it produces GHG (aka whether it is CN) seems to be a matter of C-accounting.

216.99.185.50 (talk) 16:46, 6 December 2007 (UTC)

[edit] Ethanol not Methanol

This work by George Huber at UMass/Amherst -- this looks like "destructive distillation", that produces METHANOL, not ethanol. Methanol has a higher boiling-point and does not burn as efficiently as ethanol. It is also much more toxic than ethanol. Further, the residue from the distillation is quite toxic, as opposed to ethanol-fermentation residue which can be used as fertilizer or perhaps cattle feed. Carl Ponder (talk) 05:18, 27 April 2008 (UTC)

This article should probably be split into "Cellulosic Biofuels" versus "Cellulosic Ethanol". The "Cellulosic Ethanol" might actually be rolled in with "Corn Ethanol" and put the comparisons there. —Preceding unsigned comment added by Carl Ponder (talk • contribs) 05:32, 27 April 2008 (UTC)

[edit] Corporate shill article?

Wow. I had no idea so many companies were lining up to tout their companies and technologies here on wikipedia...this is unacceptable. The article is about bio-fuel creation, not bio-fuel-creating-companies. Please clean up this article to cut out the corporate shill (or more like sh**) factor here. Twunchy (talk) 06:30, 20 May 2008 (UTC)


[edit] what?

I think I have a reasonably working antenna for corporate bullsh*t - but this page doesnt seem to me to push any particular company...

Obviously working farmers and gardeners need to compost all their own waste - what is missing is the link to taske energy from domestic and commercial waste - pretty well everything that is junked (re-cycling metals, of course, being something different) Tom fordo (talk) 21:48, 1 June 2008 (UTC)