Tuesday, October 07, 2008

Water Washing Revisited

Ok, I've taken a detour from the dry wash resin tower, which has been great, to experiment and test something I just read about water washing.  

Up til now I've been using standard tap water from a garden hose and the use of a mister.  Washing would take on average 3-4 days before I was able to use the biodiesel.  I read on the Infopop Biodiesel forum about the use of hot water and static washing as a way to pull out the soap from the processed biodiesel.  So I tested in a small beaker with some very hot water and WOW soap dropped like an anchor within seconds!  I let this sample set and within an hour I had mayonnaise at the bottom of the beaker.  I washed the sample maybe a total of 4 times with  a fraction of the water I would have regularly used.

So I decided to test on a 11 gallon batch to see if the results were the same.   I used the turkey fryer to bring the 3 gallons of water to a boil, overkill most likely and poured it in.  I let the batch settle for a few hours and came back and drained off the soapy water.  I repeated this process 3 times and my biodiesel was perfect!  I think I lucked out on this batch as the oil wasn't as heavily used thus making the soap content less.  On the batch I tested from the Vietnamese place the oil had been used pretty hard and there was a crap load of soap and would have most likely required a few more washes.  But the end result would have still required less water and speed up my washing time.

I will reserve this technique for use on the oil that has been heavily used in order to limit the amount of soap introduced to my resin thereby extending its life.

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