Joined: Mar 04, 2005 Posts: 2584 Location: New Zealand
Posted: Fri Jan 11, 2008 9:01 pm Post subject: Ethanol Solution: Just Add Water?
Ethanol Solution: Just Add Water?
Quote:
Dautzenberg and Netherlands-based client Process Design Center BV were investigating new ways to dry ethanol and stumbled across unexpected interactions among water, ethanol and gasoline. “We knew of the problems in drying ethanol,” he said, referring to the capital- and energy-intense employment of molecular sieves in dehydration. “We tried to find another way, so we asked ourselves, ‘Why not use gasoline to dry the ethanol?’ The hydrous ethanol and gasoline mix should not have been miscible, but it was fully miscible.” As a result, a ternary equilibrium diagram was formed. “We went to Shell in Holland with this information, and they said, ‘This cannot be true,’ but they investigated it further only to arrive at similar results,” Dautzenberg said.
Following the nonlinear evaporative curve for ethanol blends, which displays the worst property characteristics at 6 percent and improves dramatically when percentages surpass 10 percent ethanol, water problems in ethanol-blended fuel are much the same. “Five or 6 percent ethanol is a very dangerous area,” Dautzenberg said. “Even if there is only a little water present, it will separate with the water on the bottom.” The simple solution: Add more azeotropic ethanol (96 percent alcohol, 4 percent water). “We could go up to 20 percent to 30 percent,” said Dautzenberg, adding that a U.S. EPA waiver is needed to do so.
Eliminating ethanol drying could offer producers a 20-cent-per-gallon production savings and drop investment costs. The reduction of energy consumption at the plant could also make U.S. ethanol production more sustainable—by up to 50 percent, Dautzenberg contends. While more studies are needed to look at pipelining 15 percent or more hydrous ethanol in gas through petroleum pipelines, Dautzenberg said the principles should hold steadfast. “If you premixed a certain higher percentage of hydrous alcohol and gas, the water-gas-ethanol mix will remain homogeneous—and therefore no corrosion concerns,” he said.
ethanolproducer _________________ Human history becomes more and more a race between education and catastrophe. H. G. Wells.
Fatih Birol's motto: leave oil before it leaves us.
Joined: Mar 04, 2005 Posts: 2584 Location: New Zealand
Posted: Fri Jan 11, 2008 9:11 pm Post subject: Re: Ethanol Solution: Just Add Water?
Fuel economy study shows promise for mid-range ethanol blends
Quote:
A new study indicates that higher ethanol blends in gasoline might be optimal for better fuel mileage. Funded by the American Coalition for Ethanol and the U.S. DOE, the study found that ethanol blends between 20 percent and 30 percent, and possibly as high as 45 percent, will yield a higher fuel economy than revealed in the past.
Four 2007 model vehicles—three nonflexible-fuel cars and one flexible-fuel car—were road- and laboratory-tested: a Toyota Camry, a Ford Fusion and two Chevrolet Impalas. One Impala was the flex-fuel vehicle.
Researchers started with regular gasoline and performed nine separate tests, increasing the ethanol blend at 10 percent increments up to E85. Vehicle speeds ranged from 0 to 60 mph, with an average speed around 20 mph. Scientists noted the point at which each vehicle engine experienced a “fault code”—when the vehicle detected either an ethanol or oxygen level that wasn’t operable. Each test was conducted in triplicate for verification purposes.
The vehicles had varying responses to the test blends of ethanol compared with gasoline. “It’s conceivable that [the results] are vehicle-specific,” Aulich said. “The optimal blend could vary from vehicle to vehicle.”
The Toyota and Ford operated best with an E30 blend, while the flex-fuel Impala gained 15 percent over its standard fuel economy with an E20 blend. Unexpectedly, the nonflex-fuel Impala’s optimal blend appeared to be E40. “Some of the results surprised us,” Lamberty said. “The study shows that the correlation between [British thermal units] and mileage is a myth.” Fuel economy had previously been based on the per-gallon Btu content.
ethanolproducer _________________ Human history becomes more and more a race between education and catastrophe. H. G. Wells.
Fatih Birol's motto: leave oil before it leaves us.
Joined: Sep 17, 2005 Posts: 149 Location: The Netherlands
Posted: Sat Jan 12, 2008 10:50 am Post subject: Re: Ethanol Solution: Just Add Water?
cipi604 wrote:
More ethanol made from food? Good!
Millions of tons of perfectly fine foods are wasted each and every year, might aswel make some ethanol instead, don't you think?
Maybe if there's less food available people will think twice before buying that pack of milk which was thrown out unopened last week. Not to mention two thirds of the US having a slight weight problem.
Posted: Sat Jan 12, 2008 12:30 pm Post subject: Re: Ethanol Solution: Just Add Water?
All I can think of is all of those chemical engineers, and the decades of experience with this stuff, nobody tried to mix the gas and ethanol together before dewatering to see if it was feasible.
It goes to show how a profession gets stuck in a rut, and never rethinks some of these fundamental processes.
Posted: Sat Jan 12, 2008 3:15 pm Post subject: Re: Ethanol Solution: Just Add Water?
Thanks Graeme for a great find! I am also amazed that this basic research of optimal blending with the ethanol as a stable azeotrope was not covered before (or was lost somehow). Ethanol has been a problem child and I agree that corn to ethanol is simply insane to scale up for all the previously listed reasons. But being able to formulate gasoline with a 20 to 40 % alcohol + some water content that is tanker and pipeline viable is stunning. Cellulosic and waste stream generated ethanol can then plug in to augment petroleum derived liquid fuels on a large and fungible basis.
Large scale conservation plus innovation may buy badly needed time to work on alternative methods and technologies. We still of course, have to avail ourselves of the innovations, actually make use of the additional time with concrete action, and then make the change.
Pup55 is right, being stuck in a rut for a long time cuts the rut so deep you become blind to what is outside of the rut.
Joined: Apr 28, 2005 Posts: 3454 Location: West shore Lake Eire, MI, USA
Posted: Sat Jan 12, 2008 6:13 pm Post subject: Re: Ethanol Solution: Just Add Water?
pup55 wrote:
All I can think of is all of those chemical engineers, and the decades of experience with this stuff, nobody tried to mix the gas and ethanol together before dewatering to see if it was feasible.
It goes to show how a profession gets stuck in a rut, and never rethinks some of these fundamental processes.
The funny thing is here in the northern tier states we mix Drygas which is Isopropynol, Methanol or Ethanol into our gas in the winter to absorb the water condensation in the tank and get it to mix with the gasoline so that it doesn't form ice crystals and clog up the fuel system.
There were incidents back in the late 1970's and early 1980's when Gasahol (E-10) was first introduced where sly gas station owners were caught adding water to their big tanks knowing it would streatch their sales with little costs to them. _________________ Oxygen: - An intensely habit-forming accumulative toxic substance. As little
as one breath is known to produce a life-long addiction to the gas, which addiction invariably ends in death.--Isaac Asimov
Joined: Jun 21, 2006 Posts: 1205 Location: Burgundy, France
Posted: Sat Jan 12, 2008 6:19 pm Post subject: Re: Ethanol Solution: Just Add Water?
Eli wrote:
Ethanol at this point is a very bad joke, which would you rather do eat or drive?
It all depends how you approach it.
If you're a large corporation, and use corn for example, your goal is to produce ethanol. Any by-products are just waste, or use inordinate amounts of fossil fuel energy to dry.
However, in a permaculture approach, distilling ethanol has an EROEI upwards of 9-1 and the wet by-products can be used to feed cattle without the starch in corn (and without the drying), so they actually gain more weight than from the corn itself and have less veterinary problems. So the 87% or so of current corn production that is used to feed cattle can still be used to feed cattle but also produce ethanol.
Depending on the production scenario, instead of feeding cattle, the solubles can be digested in an anaerobic methane digester (the solids can be fed directly to beef/pigs/poultry), producing more energy than is required in the whole cooking/distilling operations. The "waste" from the digestion can be used as a fertiliser and the CO2 from the methane production (~40% of the gas) can be sent to algae in intensive fish production (algae are capable of 10% efficiency in photosyntheses with enough CO2, compared to 1-3% for land-based crops). The CO2 from the actual distillation can also be used to feed greenhouse crops, increasing overall biomass production 2 to 3 times.
So, you can get alcohol basically for free (in net energy terms), and with increased production of other elements of the farm (including topsoil).
Obviously, this is better and more efficient in a small scale outfit. I'm currently trying to go through the hoops to get a distillation permit in France. Wish me luck!
Check out David Blume's book, "Alcohol Can Be A Gas". It's been over 20 years in the writing and is stunning. _________________ All that we are is the result of what we have thought. The mind is everything. What we think we become. - Buddha
Posted: Sat Jan 12, 2008 7:56 pm Post subject: Re: Ethanol Solution: Just Add Water?
davep,
We have covered Mr. Blume's book to some extent
here recently. The heart and soul of the debate for me
was that when you extract the ethanol energy from
farmland via corn or anything else, the soil has to get
replenished regardless to make up the loss. Food as
fuel on a large scale is my very last choice on a decent
sized list of possibilities. Crop land does not settle for
carbon credits, nor nitrogen or potash or phosphate
credits or chits, and it does not settle for the fact that
it's losses are being made up for by replenishments
elsewhere on earth and are therefore neutral.
Joined: Jun 21, 2006 Posts: 1205 Location: Burgundy, France
Posted: Sat Jan 12, 2008 8:04 pm Post subject: Re: Ethanol Solution: Just Add Water?
efarmer wrote:
davep,
We have covered Mr. Blume's book to some extent
here recently. The heart and soul of the debate for me
was that when you extract the ethanol energy from
farmland via corn or anything else, the soil has to get
replenished regardless to make up the loss. Food as
fuel on a large scale is my very last choice on a decent
sized list of possibilities. Crop land does not settle for
carbon credits, nor nitrogen or potash or phosphate
credits or chits, and it does not settle for the fact that
it's losses are being made up for by replenishments
elsewhere on earth and are therefore neutral.
BTW, large scale production is the last thing on Blume's mind. He's a permaculturalist (as I'm sure you know). _________________ All that we are is the result of what we have thought. The mind is everything. What we think we become. - Buddha
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum
News
Discussions
Resources
Members
Forum FAQ
Search
Usergroups
Profile
Log in to check your private messages
Log in
