Hi Ricardo, Ken, Marc and all >As far as I know, sodium chloride cristals are naturaly anhidrous. It seems >to me that this will not work.
Sodium chloride is very hygroscopic (absorbs water). I'm interested to know how much water it will absorb before it becomes saturated. Mathewson provides some information on using salt in "The Manual for the Home and Farm Production of Alcohol Fuel" (chapter 12). http://journeytoforever.org/biofuel_library/ethanol_manual/manual_ToC.html "A second method takes advantage of the fact that water will dissolve in most salts, but ethanol will not. Therefore, water can be removed (although not entirely) by filtering the alcohol/water through dry salt. Almost any 'hygroscopic' (water absorbing) material such as calcium salt, various sulphates, phosphates and similar materials will work. However, common rocksalt, such as used in water softeners is cheap and available. An apparatus such as described in Chapter 7 for sprouting malt can be used. Fill the drum or container with rocksalt. The alcohol/water is poured in at the top and filters down through the salt. Relatively water-free alcohol is collected through holes or a valve at the bottom of the container. Remember that the salt must be dry. After absorbing water from a certain amount of alcohol, the salt must be re-dried either in an oven or by spreading it out in the sun." This appeals because salt is cheap, ubiquitous and easily dried. But the point about how much alcohol will stick to the crystals is an interesting one. Mathewson first describes the industry method of mixing benzene with the ethanol to render it miscible with gasolene. Benzene's nasty stuff indeed, but it seems that some gasolene in the ethanol won't disturb the transesterification process, so no doubt some benzene wouldn't disturb it either. Benzene's probably easy to get and cheap - or at least it used to be (like quicklime!!). Mathewson says: "A good system might be to use both of the methods described above. First, most of the water in the alcohol is removed by the salt method, and then the blend is prepared with benzene. The more water that can be removed from the alcohol, the less benzene will be needed. Benzene will have to be purchased (the cheapest technical grade is fine) and can be used only once. The rocksalt can be dried and used many times." >FYI I tried to dehydrate 95% ethanol with Copper Sulphate, that has 5 mols >H2O, previously dehydrated by calcination. It didn«t work. You need a lot >of anhydrous salt and you loose a lot of alcohol sticked to the crystals. >Later I thought to use anhydrous calcium chloride, but now there are several >ideas discussed in this forum, that I think will work better. Are copper sulphate and calcium chloride more absorbent than sodium chloride? Which is the most absorbent salt? Marc's ref on glycerine is most interesting, though it brings us back to the original question of purifying the glyc. However, maybe simply boiling off the water content would work? Much easier than distilling the glycerine. The other method is using corn grits: http://journeytoforever.org/biofuel_library/ethanol_grits.html But this, as with 3A zeolyte etc, means treating the vapour, not the liquid ethanol: ie, an add-on to the distillation process. >Ref. the translation, Marc will do it much better !! I get the feeling Marc isn't mad about the idea, and who can blame him - or you, Ricardo! :-( Ah well, I guess it's a good thing for this to happen to us hegemonistic Anglophiles occasionally (often?), puts things in perspective, eh? >Ricardo. >----- Original Message ----- >From: Ken Provost <[EMAIL PROTECTED]> >To: <biofuel@yahoogroups.com> >Sent: Thursday, May 10, 2001 1:23 PM >Subject: RE: [biofuel] Glycerin and absolute alcohol > > > > > > > >By the way, Ken Provost, if you're reading this, salt (sodium > > >chloride) is cheap and obtainable enough, and easy to dry. Any idea > > >how much water a pound/kilo of salt would absorb? > > > > > > > I read EVERYTHING :-)! Thx for reminding me -- I actually bought a big > > box of rock salt to play with, and it's been languishing in the pantry. > > I'll get on it this weekend -- it wouldn't have to be very efficient, > > considering the cost, as long as you don't lose too much alcohol just > > sticking to the crystals... :-) Good luck, look forward to the results. Best wishes Keith Addison Journey to Forever Handmade Projects Tokyo http://journeytoforever.org/ Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html To unsubscribe, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
