----- Original Message ----- From: "Appal Energy" <[EMAIL PROTECTED]> [snip] > And yes, the same percs apply for new oil, although perhaps to > lesser degrees, depending upon the FFA content of the fresh oil. > > Todd Swearingen > Todd, what would you suggests as a reasonable cut off point for the home brewer to decide between one step/base and acid/base? Someone else has suggested 7g/L but I would think that is a bit high.
One aspect of the acid/base method does not seem to have been given much attention. After the acid stage the reaction mix is still acidic. FFAs have been reduced but the sulphuric acid is still present. This residual acid will react with the NaOH added in the base stage and give an incomplete reaction unless it is accounted for. So I would suggest a titration before the base stage, taking into account the dilution effect of the initial dose of alcohol on the oil. If more than the recommended ammount of conc sulphuric acid has been used (to push the reaction by binding the water produced) compensating for the acidity becomes very important. My first efforts at acid/base produced an incomplete reaction, which led me to the above. On a batch of WVO titrating at 16ml the single stage base method gave a raw 60% volume yield. The BD solidified and had to be liquified before it could be washed. Acid/base method of the same oil gave a raw volume yield of 105% when the titration ammount of NaOH was used in the second stage. The BD from the acid/base method was liquid. Regards, Paul Gobert. --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.370 / Virus Database: 205 - Release Date: 5/06/02 ------------------------ Yahoo! Groups Sponsor ---------------------~--> Will You Find True Love? Will You Meet the One? Free Love Reading by phone! http://us.click.yahoo.com/Deo18C/zDLEAA/Ey.GAA/FGYolB/TM ---------------------------------------------------------------------~-> Biofuel at Journey to Forever: http://journeytoforever.org/biofuel.html Biofuels list archives: http://archive.nnytech.net/ 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/
