Joe, I've been wondering about this myself. This was, in part, what I was asking. Do we simply have to neutralize the mix or do we have to achieve a particular pH?
Would it be possible to measure the amount of acid needed to bring a known volume of the glycerine mix to the desired pH and then extrapolate to the volume of cocktail we have at hand? Todd S. describes (at JTF: "Separating Glycerine") how to calculate the amount of acid needed for glyc. cocktail of unknown history. It is effective, but one must have patience. I suspect that many people do not split the mix because it's a bit confusing or sounds difficult. Tom ----- Original Message ----- From: "Joe Street" <[EMAIL PROTECTED]> To: <Biofuel@sustainablelists.org> Sent: Monday, May 15, 2006 2:49 PM Subject: Re: [Biofuel] Separating Glycerine > Further to Tom's inquiry; > > My issue is that I have a small reactor and so I only produce a small > amount of the glycerine cocktail. By the time I have a cubie full of > cocktail it is the remains of several batches of fuel which makes it > difficult to guage the amount of caustic it contains. Is there a way to > titrate the cocktail? If you don't want to answer just say bat guanno > and I'll get the hint. LOL > > Joe > > Thomas Kelly wrote: > >> Hello to all, >> The short version: >> 1. To split the glycerine cocktail must one merely neutralize the >> NaOH/KOH used to produce it or is it necessary to go beyond neutral, to >> acid? >> 2. If it must be acidic, >> if one knows how much H3PO4 it takes to neutralize the mix, can one >> predict how much more H3PO4 it will take, to get the split? >> >> The long version: >> On 4/10/06 Todd Swearingen, in a post entitled "Re: Separating >> Glycerine" suggested that I would need to add 510 - 590 ml of 85% >> phosphoric acid to each cubie (4.5 gal/17.7L plastic container) of >> glycerine cocktail to achieve a split. >> Sure enough, when I added 540 ml (lowest) - 580ml (highest) of 85% >> H3PO4 to the next cubies of glycerine mix I got separation into mineral >> precip, crude glycerine, & free fatty acids. >> I've been wondering ever since how he was able to make the >> calculation/prediction .... or is he just a good guesser? >> >> On 12/02/05 Bioclaire Nederland described how to calculate the >> amount of H3PO4 to add for separation if one knew the amount of NaOH >> used to process the WVO that yielded the Glycerine cocktail. (See >> "separating Glycerine" & "separating Glycerine Mistake!"). >> The explanation is based on the equation for neutralizing NaOH >> using H3PO4. >> H3PO4 + 3NaOH ------> Na3PO4 + 3H2O >> 1 Mole (98g) of H3PO4 will neutralize 3Moles (120g) NaOH >> >> If one knows how much NaOH (or KOH) was used in the batch(es) that >> produced the Glycerine cocktail it should be possible to calculate how >> much H3PO4 it would take to neutralize (and split?) the mix. >> >> Here is where the problem, and questions come in: >> The Glycerine mix I was using (4.5 gal/17.7L) containers each came >> from two 76L batches (152 L WVO, total). >> The oil I used for these batches titrated at 1.0 - 1.5 g NaOH/L of >> WVO. (684 - 760 g of NaOH) >> Adjusting for 85% H3PO4 (115g of 85% H3PO4 would contain the 98g - >> i.e. 1M.- of H3PO4) and using the density of 85% H3PO4 (~ 1.59g/ml), >> that I should only need 460ml of the 85% H3PO4 to neutralize the lye >> used to process the oil. >> Not all of the lye is in the glycerine cocktail. Some is in the BD. >> I use 0.20 ml H3PO4/L of oil processed when I do my first wash (15ml/76L >> batch or 30ml for two batches). This results in wash water very close to >> neutral suggesting to me that approximately 50 g of the lye used to >> process the WVO comes out in the BD, not in the Glyc. mix. The 710g of >> lye that is in the glyc. mix should only take about 430 ml of the 85% >> H3PO4 to be neutralized. >> >> None of the cubies would separate w less than 540ml of the 85% >> H3PO4. This suggests that it takes more than merely neutralizing the >> glycerine mix to get it to split. >> (Answer to Ques #1?) >> Note: I'm doing a lot of this in my basement or in a shed out back, >> not a lab. >> So how did you do it Todd? Neutralize + 20%? >> If it's a secret, include the word iguana anywhere in your response >> and I'll drop the subject. >> Still puzzled >> Tom >> >> >> >> >> >> ------------------------------------------------------------------------ >> >> _______________________________________________ >> 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/ > > > _______________________________________________ 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/