>Are you pumping the liquid solution, or just the vapors? Just the vapor is moving across. You have space over the liquid and the "air" is connected to a cold space that is lower so the cold air is stable. As the alcohol becomes "dew" the partial vapor pressure renews the concentration. A refrigeration system has its evaporator as the insulated trap and the condenser heat is put back into the brew. Or the cold trap is cooled by ambient or cold water. In my neck of the woods the great outdoors gets very cold in winter. Enormous heat sink.
>Where or what is Robin Hood's Barn? A site for others with similar interests? An expression meaning you wander all over. All of Sherwood Forest was Robin's so you could wander a fair bit going "round his barn". Kirk -----Original Message----- From: motie_d [mailto:[EMAIL PROTECTED] Sent: Friday, February 08, 2002 7:55 PM To: biofuel@yahoogroups.com Subject: [biofuel] Re: ethanol distillation I'll interpose my thoughts into the body of your message. --- In [EMAIL PROTECTED], "kirk" <[EMAIL PROTECTED]> wrote: > The relationship of pressure to yeast viability is an unknown to me but if > the liquid column is deep enough that should establish a viability zone and > a piece of filter (plastic or plasticized paper?) could keep all the > yeasties happy below that barrier. That sounds like an excellent thought to develop further. 2 feet below the surface, the pressure is liable to be above normal atmospheric pressure. Yeast viability under vacuum may well be a moot point. As to vapor pressure I think you are > asking what it boils at. Yes. I know the boiling point at atmosphere, and it is too high for the Yeast to survive. I want to reduce the pressure, to reduce the boiling point of the Ethanol portion. I don't want to remove the water. > You will probably use less energy purifying by freezing rather than > vaporizing Freezing will kill the Yeast, stopping the fermentation process, and raising the alcohol content above toxic levels for the Yeast, by segregating the water in the solution. The alcohol will still be there. I need to remove the alcohol, and do it at a fast enough rate to keep the Yeast alive and fermenting vigorously. My current temperature parameters are to keep the mix between 75F and 125F, with 95F probably being the ideal. > I think freezing H2O only uses 1/3 as much energy as evaporating. I believe you are correct, but I didn't thoroughly explain what I am attempting to do. I don't want to simply distill the alcohol from a finished ferment, I want to keep the ferment continuously active, and remove the alcohol to keep it below toxic limits. > > Another way, since it can be slow, is a cold trap in a sealed system. The > alcohol will transport faster than the water. > Vacuum systems where you pressurize the output of the pump in a cold trap > have the product going through a pump and contamination is a given. If not > for human consumption I suppose it doesn't matter but the energy > requirements are higher than just a trap using ambient heat to transport the > product. It doesn't have to boil and the cold trap condenser heat can be put > back in the source vessel if using a refrigeration system. Can you expand on this a bit? Are you pumping the liquid solution, or just the vapors? > > If your tank is at 125 F I would think 75F would get condensate at a good > enough rate to keep concentration below yeast toxicity. > Could get 75F probably by running household water through a tank and then to > house. Most water is 55F or so I would think. I assume you use the sun to > heat your tank. Slowest process of all but uses the least energy. Putting heat in is not a problem. I'll use wood fired hot water to put in the bare minimum needed. > > Just some meandering round Robin Hood's barn but I think there is a seed or > two in there. Where or what is Robin Hood's Barn? A site for others with similar interests? > > Kirk Thanks for your input. Please don't stop now. Motie Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Please do NOT send "unsubscribe" messages to the list address. To unsubscribe, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ --- Incoming mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.323 / Virus Database: 180 - Release Date: 2/8/2002 --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.323 / Virus Database: 180 - Release Date: 2/8/2002 ------------------------ Yahoo! Groups Sponsor ---------------------~--> Get your FREE credit report with a FREE CreditCheck Monitoring Service trial http://us.click.yahoo.com/ACHqaB/bQ8CAA/ySSFAA/FGYolB/TM ---------------------------------------------------------------------~-> Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Please do NOT send "unsubscribe" messages to the list address. To unsubscribe, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
