I took five gallons of freshly reacted BD and passed it slowly thru a two foot high tube filled with hard wood planer shavings . BD looked great and clear after the first two passes. So I repeated for a total of six passes and the BD stayed as clear as it was after two. Then I did a shake test with distilled water and it resulted in showing still a lot of soap.

Needless to say I was expecting a cleaner shake test. Any comments?

Are you sure the MeOH is all out?

I have been experiencing a similar problem lately. If you haven't gotten the methanol out, it can actually show clear in a shake test as the soap is still in suspension. After letting it sit for a bit, you can do another shake test and see soap again. Eventually the soap will settle out, but you have to drive off the methanol.

Another thing is the BD needs to have more residence time with the shavings. If you are just passing it through the pipe it probably isn't getting enough.

I imagine that there is still methanol present so I'll work on that and see what happens next time. I have it valved down to just a steady but very small stream but I can give it more time in contact. Thanks for the help.

One other thing, I was surprised to see the wood sink once saturated instead of floating.

Hello Raften. I was skeptical about the wood removing all the soap and still am. I run my Bd through the woodchips and then I run it to a wash barrel. It speed my wash process up to an unbelievable rate. I can wash the fuel with 20 gallons and beat it up with the water on the first go around. I am happy with this system because even though I am still washing with water it is very quick and I dropped my water usage by about 75%.

Hi Wal, That is the same as I want to do, just sounds like I need to be better at getting the methanol out to make it work. What method do you use to get the methanol out?

Raften,

Of course you can demeth by heating the BD up to around 160 degrees and reclaim the methanol for later use with a condenser. You can then bubble the BD for about 24 hours to get the residual methanol out prior to settling for a few days or weeks. Then run it through the wood shavings.

Jehu was getting good results straight from the processor using wood chips. I have not been able to duplicate his results. I continue to use the wood chips to filter out the soap prior to running it through the resin towers. The key here is time. If you can get a few batches ahead, time will work in your favor. I have four batches settling now. That is about a month's worth of fuel.

I am about to start using a centrifuge setup similar to Fabricator's for final filtration or prior to the resin towers. I don't see any reason to introduce water to the process.

quote:

Originally posted by Raften:
Hi Wal, That is the same as I want to do, just sounds like I need to be better at getting the methanol out to make it work. What method do you use to get the methanol out?

I used a bubbler in the settling tower but it did not work. My settler only has a 3/4 inch vent at the top. So I either need to do the venturi soon or not do anything at all. You will blank your pants when you see the difference the wood chips make. Your washing will go so fast you may not worry about the rest of the methanol.

OK, sounds like my drying rig will do the job getting rid of the methanol, just have to not use the fan. I'll give it a try next batch. Finely got some calcium carbide for my manometer and since I have always thought my finished BD is very dry I am about to find out for sure.