>Lagonisa,
>
> > The problem is
> > that I have also read that due to the reversibility of the reaction,
>
>The reaction is not exactly reversible. "Reversability" would require the
>three glycerides and the glycerol recombining. That doesn't happen. Once the
>glycerol is cleaved it is out of the picture.
>
>You're suggesting MeOH recovery at the point where the reaction is complete
>and the glycerol has yet to settle out. However, that's not altogether
>adisable due to the continual mixing of excess catalyst with the methyl
>ester.
>
>If you reduce the volume of alcohol via evaporation at this point there
>would be a propensity for some of the ester to fracture ("back crack") into
>FFAs and then convert to soap. Mind you that "back cracking" can only occur
>up to the point that all the catalyst is consumed in soap making.
>
>If you can monitor the reaction and insure that the balance of catalyst is
>infintesimally small beyond what is required to guarantee 100% completion,
>erego yielding but a small and controlled amount of extra soap production,
>then there might be some merit in extracting the alcohol prior to the
>glycerin cocktail settling.
>
>Otherwise? Probably none.
>
>Todd SwearingenHi Todd Yet that's what Dale Scroggins does, apparently with good results. The touchless processor http://journeytoforever.org/biodiesel_processor.html#touchfree http://home.swbell.net/scrof/Biod_Proc.html Michael Allen and Gumpon Prateepchaikul's set-up at Prince of Songkla University in Thailand also reclaims the methanol at the end of the processing stage, though differently, and with high efficiency and a high-quality product (they test it). I wonder if this isn't somewhat theoretical, as with the idea that using acid in the wash will definitely backsplit biodiesel to FFAs and must definitely be avoided. If properly done - which of course shouldn't be merely so solve an emulsion problem (improve the process!) - it has the advantage of thoroughly neutralizing the catalyst, at the cost of traces of FFA which remain well within the standard specs. So here the same perhaps applies, as you indicate - a well-controlled process with the right amount of catalyst and the right amount of everything else too. Needs and economics will differ from case to case, and I think methanol recovery should be an option at each of the three possible stages it can be done - straight after processing, using the existing heat (to start with), recovering excess methanol from both the ester and the by-product; recovering the excess methanol from the by-product cocktail (that is most of it), which leaves the balance to be accounted for (in the first wash water); recovering the excess methanol from the glycerine itself after separating the by-product components (which still leaves the balance in the first wash water). Best Keith > > Hello to all: > > > > I have read some contributions to this group about methanol recovery > > and the different options. I would like to try the recovery before > > separation of bio and glycerol using a condenser that would receive > > the methanol fumes after finishing the reaction. I have a processor > > were I get 75¼C-80¼C as it is pressurized to 0,7 bar. The problem is > > that I have also read that due to the reversibility of the reaction, > > if after finishing my reaction I remove the methanol by reducing the > > pressure and directing the vapours through a condenser, or even I > > apply vacuum after despressurizing to do it faster, I can get a > > reduction of the conversion transforming some biodiesel into oil > > again. My question is: has anyone in this group measured or > > experienced this fact? Is there a real decrease of the yield or > > conversion? > > > > Lagonisa ------------------------ Yahoo! Groups Sponsor ---------------------~--> Buy Ink Cartridges or Refill Kits for your HP, Epson, Canon or Lexmark Printer at MyInks.com. Free s/h on orders $50 or more to the US & Canada. http://www.c1tracking.com/l.asp?cid=5511 http://us.click.yahoo.com/mOAaAA/3exGAA/qnsNAA/FGYolB/TM ---------------------------------------------------------------------~-> Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuels list archives: http://archive.nnytech.net/index.php?list=biofuel 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/
