Dear Paul, Thanks again for the feed back.
The SG results form my tests with pre-treated oil are as follows. Note, all are unwashed except for the normal brew sample: Test 1, 20 mil (8%) methanol. SG 0.9111 Test 2, 25 mil (10%) methanol. SG 0.9051 Test 3, 32 mil (13%) methanol. SG 0.9036 Test 4, Same as test 2 using another mix of preteat oil. SG 0.9056 My normal brew using 17% meth and titration + 1.4 grams. SG 0.8946 Questions for anyone: What SG number should we be aiming for? Do you have any info on viscosity measuring? As in what are we aiming for and, have you any info on cup type measurers as in volume, hole size and time for different viscosities. Regards Trevor > > Trevor, please excuse delay in replying> > > > I have gone on to process upper layer (eg top 2 layers mixed!) > > Titration of oil was 0.6 mil. I normally get 1.8 to 2.5 mil form my > > one supply. > > Titration of upper layer would suggest that there was not enough residual > caustic in glycerine to neutralise FFA in oil. Therefore not enough excess > for transesterification. > > > I normally use about 17% methanol. > > 17% methanol wouldn't leave much methanol in the glycerine. > Would hardly be worth the trouble of recovery. > Rate of conversion of WVO would also be low, generally agreed that 20 to 25% > methanol required for high rate of conversion WVO to ester. > At that use rate methanol recovery becomes worthwhile. > Options 1/. Distillation > 2/. Mix fresh WVO with glycerine > 3/. Add glycerine to next batch, use lower % of methanol. > 4/. Can anyone suggest another method? > Whilst option 1 is well established options 2 and 3 are as far as I know > experimental. > 2 would require higher than normal levels of NaOH so that enough was carried > over in the glycerine to both neutralise the FFA in the WVO and catalyse the > reaction. This in turn produces its own problems. > > The mixture of WAF and glycerine did not turn out as planed. > Had hoped that upon cooling thjree layers would form. BD,solid unreacted WAF > and glycerine. Result was two levels, semi-liquid fat above glyverine. > > >So tried 3 test batches of 250 > > mils. Used 0.5 to 0.6 grams of caustic in all batches. Mixed in > > blender for 10 minutes at 30 to 40 deg C. > > Test 1, 20 mil (8%) methanol > > Test 2, 25 mil (10%) methanol > > Test 3, 32 mil (13%) methanol > > Have not had much success with such low levels of methanol,they are all > below the ammount required by the reaction and an excess is usually required > to push the reaction towards completion. > With the variable and poor quality feedstocks that I use experienced a lot > of failures before moving up from 15% methanol. > > > In all the stuff I have read re-titration of oil it says to add 3 > > to 3.5 grams to the resulting mils and use this as your grams per > > litre. With test batches I find I only need to add 1.4 grams to > > titration result to give good result. Have double checked my caustic > > solution and method and think everything is correct. I this a common > > result?? > With good quality oil the result may appear satisfactory but I would suspect > that the reaction has not gone to completion without the 3.5g to act as > catalyst. > A fair guide would be the ammount of glycerine. Its volume should > approximate the ammount of methanol used (given that enough methanol was > used to ensure complete reaction). > With well used WVO/WAF I find that more than the titrated ammount of NaOH is > required for satisfactory reaction/stability of product. > > Look forward to reading further results, > > Paul Gobert. ------------------------ Yahoo! Groups Sponsor ---------------------~--> Buy Stock for $4. No Minimums. FREE Money 2002. http://us.click.yahoo.com/BgmYkB/VovDAA/ySSFAA/FGYolB/TM ---------------------------------------------------------------------~-> Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html 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/
