Oak chips
 

I am experimenting using oak chips/shaving to filter my bio diesel. I have a 4 " PVC tube that is 3' tall, filled it 2/3 full with red oak chips. Poured 1/2 gal into it and turned the needle valve on the bottom to just a drip. Let it filter through and did a shake test, seperation was fast and the water was clear. After work today, ran 3/4 gal through at a little faster rate (2 hours per 3/4 gal) and what came out was a nasty brown bio. Any ideas or does anyone on the forum use oak chips?
Dave

Ive used Hard wood chips. This is what ive found you need to do. Fill your tower full. Most people ive heard of use a 55 gallon drum filled to the top with chips. You will have an in at the top and a out at the bottom. You will then need to flush the system with methanol to get the resin/sap out. Fill it up and let sit for 12 hours. Flush. Let the chips dry. Air dry or hook up an air hose. You will then be ready to use them. They wont last as long as Ion exchange resin but its cheaper. run the bio through slow. 10 gph. For best results use an ion exchange tower with resin. The chips mostly only work for soap. The ion resin will get the remaining soap and trace glycerin. Hope that helped.