Hello All,
Long Time no post.

I have been making bio in a push pull reactor (Thanks Graham) I have been recovering virtually all methanol....good so far. The deal is that the soap settles to the bittom and makes the last of the bio very hard to deal with and I have to get globs of soap out of the bottom of a 110 gallon settling tank. After a couple of batches I have a mix of soap and bio that is 2 rings up a 55 gal drum....Soooo
I put a water wash with an automatic overflow on it and it cleaned the soap out. I then took a filter bag and filled it up about 1/2 way with oak sawdust from my band sawmill. (just happen to have oak trees and a sawmill in my yard ) I circulated it for 4 hours and had crystal clear bio, passed soap test on the first drop, no dropout, and ran it through a 1 micron filter after with no sign of anything on the filter. and I think I used less water than I use cleaning my filters. The sawdust should last much longer as the methanol and most other contaminates where already removed. I then added a quart of water back to the drum and it removed it in 2 hours, I did this 2 days in a row and it appears that that the water just evaporates from the sawdust. My next test will be to take a pillow case, or something along that line and just put the pillow in the bottom of the tank. So it appears as though I can wash, dry and filter all in one tank. I will also test next batch if I could partially water wash and let the sawdust finish taking the soap, moisture and other contaminates out.

Just thought I would share what happens when I get lazy and bored at the same.

Dave

That is awesome! And, if you have your own sawmill, you are eliminating your washing efforts and component cost while also using the sawmill byproduct. Does it have to be oak? There is a large sawmill close to my house. This sawmill cuts hardwoods (walnut, cherry, oak, hickory) and dumps all the sawdust outside for anyone (usually horse trailers and livestock pens.) That would be a lot cheaper, faster, and better (as far as eliminating waste water). Nice discovery!

I have used oak, maple & lyptus successfully. I would think cherry would work fine. Not sure about walnut, but it would be worth an experiment. I have a bunch of rough hickory for a kitchen I never built. I think it would be okay as well. I just don't want to start planing & jointing until I know what I am going to do with it. Another guy uses aspen shavings. I think someone else used mahogany.

The idea behind red oak usage was that it was suggested by another forum member in England that Eco2pure was comprised mainly of red oak shavings. Red Oak is high in tannic acid. I and others have speculated that the acid might react with the soap similar to an ion exchange resin. All I know is it reduces the soap big time.

The general consensus is to stay away from the pine family due to the high resin content.

quote:

it was suggested by another forum member in England that Eco2pure was comprised mainly of red oak shavings.

That would be me. I am following Jehu at the moment and using mahogany. I currently believe any hardwood will work. Tannic acid content may be a critical factor but that is speculative. It is worth reading what Jehu has done so far as he has done significant research and experimentation leading to him using this as his sole washing method for some time now. I agree it is better to stay away from pine and the like although at least one member has had some success with softwood.

Some resin comes out a the beginning even with hardwoods.

I just did a batch with incense cedar and it worked great.