----- Original Message ----- From: Keith Addison <[EMAIL PROTECTED]> To: <biofuel@yahoogroups.com> Subject: [biofuels-biz] High FFA oils - another way <snip>
> I found an easier way though: two-stage base-base, only the first > stage doesn't use methanol, it uses (horror!) water. > > Mix the titration amount of NaOH, in this case 9.15 grams per litre > of oil, with 40 ml of water per litre of oil. > > Add the dissolved NaOH to the oil (room temperature), stir gently by > hand until thoroughly mixed. > > Settle overnight. This leaves soapstock at the bottom and some gunk > floating on the top. The water is apparently in the soapstock. > > Filter to remove soapstock and gunk - no need for fine filtering, > fine steel mesh will do (like a fine tea strainer). > > Now process as usual for virgin oil - 3.5 grams NaOH per litre of > oil, 20% methanol, 55 deg C, good and prolonged agitation as usual. > > Good product, production rate in this case 73%, slightly less than a > normal single-stage, but it's a much easier process that won't go > wrong, and it's nice not to have to make such strong methoxide as a > straight single-stage process would require with this oil, 13.65 > grams of lye per litre oil, or more like 14 grams (needs a bit of > excess lye). <snip> Slaked lime (CaOH2)can also be used to remove the FFA from WVO or high FFA biodiesel rescued from overuse of NaOH (gel) with acetic acid. Mix the lime into the WVO/BD and heat with occasional stirring to 100 deg C. The lime appears to dissolve in WVO as heated but is probably just held in suspension. Cool decant and filter. No problems with ammount of lime just use excess. Would much rather go acid/base with feedstock with FFA content this high, less wastage/recovery and acid stage allows alcohols other than methanol or ethanol to be used. Isopropanol for instance has the potential to reduce cloudpoint. Regards, Paul Gobert ------------------------ Yahoo! Groups Sponsor ---------------------~--> Sell a Home for Top $ http://us.click.yahoo.com/RrPZMC/jTmEAA/MVfIAA/9bTolB/TM ---------------------------------------------------------------------~-> Biofuels at Journey to Forever http://journeytoforever.org/biofuel.html Biofuel at WebConX http://www.webconx.dns2go.com/2000/biofuel/biofuel.htm List messages are archived at the Info-Archive at NNYTech: http://archive.nnytech.net/ To unsubscribe from this group, send an email to: [EMAIL PROTECTED] Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
