July 22, 2013, 01:13 AMGOgreaseguy
Mixing mistake, help needed
I've made about a dozen batches of biodiesel so far and all but the last batch turned out perfect. I'm wondering if anyone might have some advice for me on how to un-screw my screw-up? I started with a 40 gallon batch of used veg oil. I ran it through a 200 micron filter into the barrel and then transferred it into my mixing tank. I turned the heater on and then took my 1ml sample of the oil. I conducted my titration test and ended up using 1,136 grams of KOH which I mixed in real well with 8 gallons of methanol. By the time I transferred it into my mixing tank the oil was about 110 degrees. I then let it mix for 3 hours and 15 mins. I let it settle for about 15 hours. I then drained approx. 8.5 gallons of the glycerin (I always drain a little more than the 8 gal) from the bottom. Next I added 5 gallons of hot water to wet wash the biodiesel. I let it settle for about 2 1/2 hours. There was perfect separation. I drained off the 5 gallons. Now here's where I am sure I screwed up. Before doing my second wet wash cycle I decided that I wanted to cycle/mix the biodiesel that was in the tank. What possessed my dumb ass to do this I'm not quite sure but I set the valve positions up to cycle the biodiesel in the tank. I let it mix for like 5 minutes and then turned it off. I then added my second 5 gallons of hot water for my 2nd wash cycle. When I returned 3 hours later I discovered that instead of having approx. 5 gallons of settled wash at the bottom of my tank, I had approx. 25 gallons of light colored foam.
I have since drained off the foam into separate containers and left the approx. 15 gallons of biodiesel in my mixing tank. I'm not quite sure what to do at this point. My guess is that I wait how ever long it takes (about 1 week?) for the foam to settle. Pour it back into the tank with the 15 gallons of bio diesel I already have in there? At this point would I just continue with the wet washing cycle or, do I have to do another titration test and remix more methanol and KOH into the oil? Thank you for any help and or advice.