I set up a 55 gallon drum filled with Alder wood chips and stared dry washing two weeks ago. The first 55 gallon batch sat in the wood chips/sawdust over night and in the morning I tested it for soap and got zero PPM. I was very happy and said goodbuy forever to the water washing. I have ran three more 55 gallon batches through since then and the last batch has been sitting in the chips/sawdust for over a week and it will not get the soap lower than 600ppm. Whats happening? I tested it before it went in the chips and it passed the 3/27 test and the soap level was around 3000ppm. Could my wood chips be toasted already? It seems that everyone else has got a lot longer use out of their chips them me?
Not sure but I thought most were running the Bio through the chips slowly not letting it set in it.I run mine through at about a flow rate of a gallon and hour and it seems to work just fine.
To give an idea; RolfQuo (interview in the sig line) has used the same drums of chips for over half a million liters without the need to swap out. The drum I have has had several thousand Liters through it and is still going strong.
** Biodiesel Glycerine Soap - The Guide
- on 5 continents helping people make & sell soap from the Biodiesel Glycerine.
I wonder whats going on then? I will take some pics of my setup and show you all whats going on. I have started slowly gravity feeding the bio at about 5 gallons an hour through another 55 gallon drum filled with new wood chips to see if that will help.
make sure your titration is accurate. It is easy to get off.
Are you removing the methanol from the fuel and letting the soap settle a day or two before running through the filter drum? Try to get as much soap out before filtering. Just a thought......
Starting with 3000 ppm is high. We use a quick 5% prewash(i know, it slightly defeats the purpose, but this works well), then run through wood chips. With the prewash, we start around 300-500 ppm and finish at 0.
Quosimoto, Does your bio come out dry? Or do you dry it after the chip treatment?
Simple schematic for a pump and heater control with a high limit
Sensor for the biodiesel/glycerin layer
We dry the bio before it goes through the chips.
Ok so I took some wood chips out of the top barrol and put them into a 1 gallon milk jug and added unwashed bio and in 24hrs 0ppm soap. Why in the heck does it work in the plastic jug but not my 55 gallon drum? Maybe the soaps have settled to the bottom of the 55 gallon drum and they are slowly coming out as I drain the bio. My lower drum has a 5 micron filter turned upside down filtering the bio before it is gravity fed up the pvc pipe into the final holding tank with the pump attatched
Bio.jpg (34 Kb, 56 downloads)
Heres a pic
Well I have removed the old alder wood chips and refilled the drum with oak sawdust/chips. Everything seems to be working great again but I still have a question about demething the bio before sending it into the woodchips. How are you guys doing it? So far I'm draining the glyserin after processing is done and it has settled for at least 8 hours. Then I simply heat up the bio again to 150 degrees and boil/steam off as much methanol as I can for about 3-4 hours. Then I let it settle over night and drain off the bottom gallon, and then send the rest into the chips. Seems like the average soap levels are around 1500ppm for me after doing all of this before sending it into the woodchips. So what does everyone else do?
From my understanding RolfQuo Biodiesel and Legal Eagle use the same setup since he received his set up from them. They do not drain directly out the bottom of the barrel where you would expect the soaps to settle. They have it exit out the side near the bottom.
I have also read where people feed processed but cooled bio in from the top of the barrel where it pushes the colder settled and filtered biodiesel from the previous batch up a pipe that runs from near the bottom of the barrel out through the top bung. I would say the barrel would have to be able to hold the entire batch to work this way.
Also, my understanding is that the wood and soaps are both polar so they are attracted to one another and that is one way it pulls out the soap while sitting in the wood chips. People also pretreat the chips with methanol flushes to remove the resins and load the chips with the wood alcohol that is also attracted to the wood shavings both being polar again. This is also how the wood chips removes some of the remaining methanol after demething. Further more the methanol helps remove the soaps by holding them in suspension I believe.
This is the most complete explanation I can come up with from sources all over this forum. If there are any facts that were proven to be incorrect please let me know. There really needs to be a good write up on this topic. I have read RickDaTech dry washing article on his website and it was informative. But I feel we need to cover more on the process. This is not possible for me to do since I have no experience with this process and have only read what people are doing and what works for them.This message has been edited. Last edited by: Sting_3,
Wood chips definetly work good at removing soap, I think I just sent a really soapy batch of bio through and thats what killed my first barrel of chips. I need to start demething and settling before sending it to the chips and, I think then, my chips will last longer. Still need a good word on the best way to demeth the bio. I've read for days on the methenol recovery forum but it seems that most of the set-ups talked about are for glys/meth recovery. Not sure if the pot still/reflux column are nessesary for just the bio/meth recovery
To remove methanol, we do exactly what you do, just boil it off. No great tricks here, there is very little methanol left in the biodiesel at that point, so its not worth recuperating. There is much more methanol in the glycerin and that is why people(us included) will recuperate that.
I've been using the glycerin to pre-wash the oil before processing. Is it better to demeth the glycerin and save the methenal or better to use the glycerin for my pre-wash? The oil I've been collecting usually titrates around 4 and after the glycerin pre-wash it usually drops the titration number down to 3. Biggest benefit of the glycerin pre-wash is that it dries out all the oil and I pass my 3/27 test everytime