Re: [Biofuel] Separating Glycerine/FFA

[Thomas Kelly]

Good Day To All,      I agree with Todd S.  "As for producing NaCl from any process? The intent should be to steer processes away from creating waste products, not creating more."      I now have 10,  5gal. containers of byproduct in my shed, and more on the way. The only reasonably priced H3PO4 I have found so far comes in 55 gal drums  ....  much too much!!! I was looking at using another acid ex HCl in order to get FFA's to burn in my in-laws heating system. I want to attempt methanol recovery from the glycerine, and my wife would like to try to make glycerine soap. Would using Sulfuric acid be better in that it produces Sodium Sulfate? ...  a fertilizer ... (I'd better switch to KOH, and locate H3PO4, huh?).      I'm biting at the bit to do something w. the byproduct other than composting it.           I need some help with the chemistry. Ken Provost wrote:    "HCl works fine -- the FFA will gradually rise to the top as an odd-smelling reddish oily liquid, and the glycerine will be left in an aqueous solution at pH 3 or so (you have to overshoot the acid quite a lot to get separation of FFA, due to the buffering effect of the soap/FFA system)."       At the prices I've seen for smaller quantities of H3PO4 (500ml $18 + shipping) I'd like to be conservative w. it.       Isn't the amount of acid needed to overwhelm the buffer system related to how much soap was produced in the process? Which, in turn, was formed by the FFA's present in the WVO, and that we neutralized with NaOH (or KOH)?    If this is so, can't we get at least a ballpark figure of the amount of acid needed to separate the glycerine/FFA from a particular BD batch?     JtF: "We found that it takes about 1.5 to 1.7 ml of 85% phosphoric acid for each gram of sodium lye used in the process."  3.5g lye/L   +   titration (g/L)  =   g lye/L   g lye/L  X 1.5 or 1.7 ml/g lye  =  roughly the ml H3PO4           Are we striving for a pH of about 3 or does it vary w. WVO used?      I ask, because if a particular pH produces the sparation couldn't we use a pH indicator?(As w. Phenolphthalein - for titration of WVO)      Bromcresol green  (pH 3.8 - 5.4)      Bromphenol Blue  (pH 3.0 - 4.6)      Methyl Red  (pH 4.2 - 6.2)     If we titrated a small (1L) sample to the desired pH, we could calculate at least roughly the amount of acid needed to separate the larger batch. And this would work even on mixed batches.        This list is like a morning newspaper to me (or what I'd like one to be). There is a cast of characters here, including Todd S. and Ken Provost, whose responses I read, regardless of topic, because they have insight that I envy and a world of knowledge that I am trying to come to grips with.                 I appreciate your responses. Thanks,                                             Tom   ----- Original Message ----- From: Ken Provost To: Biofuel@sustainablelists.org Sent: Sunday, October 30, 2005 7:28 PM Subject: Re: [Biofuel] Separating Glycerine/FFA On Oct 30, 2005, at 2:19 PM, Thomas Kelly wrote: I'm having difficulty getting Phosphoric Acid. Can I use Hydrochloric Acid to separate the Glycerine/FFA ? It will produce Sodium Chloride rather than Sodium Phosphate (I use lye), but other than that, any objections? HCl works fine -- the FFA will gradually rise to the top as an odd-smelling reddish oily liquid, and the glycerine will be left in an aqueous solution at  pH 3 or so (you have to overshoot the acid quite a lot to get separation of FFA, due to the buffering effect of the soap/FFA system). When using H3PO4, I bring it back to pH 7 with ammonia, to give a fairly benign fertilizer solution for the compost or garden. Obviously, with HCl and lye, the NaCl will be fairly destructive, so the glycerine will need to be sewered or otherwise wasted. -K _______________________________________________ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (50,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/ _______________________________________________ Biofuel mailing list Biofuel@sustainablelists.org http://sustainablelists.org/mailman/listinfo/biofuel_sustainablelists.org Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Search the combined Biofuel and Biofuels-biz list archives (50,000 messages): http://www.mail-archive.com/biofuel@sustainablelists.org/