Keith Addison asks: >...Care to describe the caustic refining step >a bit further?
I do it in 30 liter batches. Take a titration, dissolve the required amount of NaOH (to just neutralize the FFA's) in enough water to make about a 15% solution, add to the warm oil and stir well. At this point there's no FFA's left, all converted to soap, but not enough water to form an emulsion. Now VERY carefully wash with hot water -- 3 or 4 washes with 8 liters each seems about right. The pros use a centrifuge at this point to break any emul- sions formed, but I find if you're very careful you may lose only a liter of your original volume of oil before the sudsing is reduced enough. After all the washes, I throw in a liter of clumping cat lit- ter and a liter of silica gel cat litter -- probably not necessary, but it scavenges the last of the soaps and does a nice bleaching job. Then I boil off any residual water and it's ready to go. Kind of elaborate, and I'm researching how far I can back off on the process, but you end up with neutral oil you could fry your chips in again, or make great biodiesel! -K ------------------------ Yahoo! Groups Sponsor ---------------------~--> See What You've Been Missing! Amazing Wireless Video Camera. Click here http://us.click.yahoo.com/75YKVC/7.PDAA/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/
