regarding methanol recovery: I just want to talk about temperatures for a moment- I use a tremendous amount of insulation on my processor- about 3 or 4 inches thick of recycled bubblewrap packaging material, and I only started using this quantity of it this winter. Previously I only used a layer or two of Reflectix. The thicker material makes a tremendous difference in how much electricity it takes to heat the mixture, and the processor retains the heat for days! I strongly recommend that anyone working with methanol recovery or other high-energy-input methods make sure that you have adequate insulation. The fact that the mixture stays hot for days (I believe I only lose about 20F in 24 hours in the cool spring nights/somewhat warm days (65-75F daytime temps) that we have, working outdorors, this past few weeks) Most of the processors I"ve seen have a small layer of mylar-coateed bubblewrap (Reflectix) or something similar- this is expensive stuff, and I've seen many people use it in exactly the same way because of the high cost- 1/2" thick. Our coop processors started out insulated this way, and I can't stress enough how much of a difference a few more inches of (free) insulating material has made. I"ve also seen many people not use any insulation at all, and have been guilty of this myself in the past. The advantage of being able to keep the mixture hot for so long, is that it's easy to make fuel, give it adequate time to completely react and settle, and then, finding it still at mostly process temperatures, only heat it a small amount to reach the boiling point of methanol at atmospheric pressures (or to just turn on a vacuum pump and start recovering under vacuum).
mark --- In biofuel@yahoogroups.com, Keith Addison <[EMAIL PROTECTED]> wrote: > >When recovering the methanol, do you heat the whole batch after it > >settles, or heat each part sepparately (biodiesel and glycerine)? > > > >Brent > > Sorry Brent, you didn't get a response to this: > > Different schools of thought on this. Some people just heat the whole > thing up a bit more after the process and recover the methanol there > and then, which has some advantages - it doesn't take much extra > heat, for instance, compared with heating all or part up again from > room temperature. Here's one such: > The touchless processor > http://journeytoforever.org/biodiesel_processor.html#touchfree > > Others say the disadvantage of this is that removing the methanol > makes the glycerine by-product much more difficult to process. The > by-product is actually a mixture glycerine, excess methanol, soaps > and catalyst, and it can be separated - the methanol content makes it > easier to work with. Here the methanol will end up in the separated > glycerine, and can then be recovered. See: > Separating glycerine/FFAs > http://journeytoforever.org/biodiesel_glycsep.html > > Others again say it's not worth trying to recover the excess methanol > from the biodiesel as most of it collects in the "glycerine" layer > anyway, so just heat the by-product. If you do want to recover the > methanol content from the biodiesel, you have to do it before > washing, which will remove all the methanol. > > There's quite a lot about this in the archives. Here are a few > previous messages, these mostly on possible water content of > recovered methanol: > > >I've used and re-used about thirty gallons of methanol so far using > >my hot pink vacuum still. At first I was worried about recovering > >water at the end of a run, so watched the condensate closely for any > >sign of cloudiness. I've never seen any. I don't think water can be > >recovered from the byproduct at anywhere near the boiling point of > >methanol. > > > >Dale > > >Dale is right, recovered methanol is OK to re-use. I have found that > >from biod made using 15% meth (v/v WVO), the glyc. yields 3% meth > >(v/v WVO) and is well worth the trouble of simple distillation at 70 > >deg C. Probably will use 20% in future for an easier life without > >unnecessary loss of costly reagent. > > > >David T > > >Any water in the mix is either tied up in soap or, at the very > >least, heavy in dissolved catalyst. Either will make the water much > >more difficult to boil. I haven't taken my rig up to high enough > >temperature to after methanol recovery to recover any water, so I > >can't be sure at what temperature and pressure water recovery would > >begin, but suspect it would be at a very high temp or low pressure. > > > >Dale > > >Sorry, I didn't make it very clear, did I? I've used much more than > >30 gallons in processing fuel. In total, I have recovered and reused > >about 30 gallons. > > > >Dale > > Which option you use is up to you really, depends what suits you and > your set-up, the kind of oil you use, and your process. There are > some further options too. One system constantly condenses off > methanol vapours and recycles the condensate back into bottom of the > mixing tank, then recovers all the excess at the end, seems very > efficient. But I don't think that set-up is doing glycerine-FFA > separation of the by-product. On the other hand, if it's good oil > you're using with low titration results the by-product will probably > stay liquid anyway and might be easy to separate even without the > excess m ------------------------ Yahoo! Groups Sponsor ---------------------~--> Get A Free Psychic Reading! Your Online Answer To Life's Important Questions. http://us.click.yahoo.com/Lj3uPC/Me7FAA/CNxFAA/FGYolB/TM ---------------------------------------------------------------------~-> Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuels list archives: http://archive.nnytech.net/ 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/
