i have read the article on drying washed biodiesel and it says you have to expose it to the air to evaporate the water. now heres my thought. if you could fabricate a container that can be sealed air tight and subject it to a lower than atmospheric state (ie. use a vacuum pump). the lower than atmospheric pressure also greatly reduces the boiling point of the water allowing it to be expelled through the pump. an example is 29 inches of vacuum water boil at approx room temp. i dont know if it would work or not but itsjust my thought on it

I'm sure this idea is out there already, but it is still good to see it come up again. I helps to keep it fresh and active.
The vacuum pump idea would work really well for me since I have lots of excess solar heated water available in the summer, but it will never be able to deliver 212*F. I can deliver >130 dang near all day, even "wasting" it by boiling water. If I can get enough vacuum to cause the water to boil at 130*F I would be set.

OK, yes, using a vacuum would work well. However, it would be much more trouble than it is worth IMHO. It would take longer and cost more to do this than to simply air dry it. Jim, you also don’t need to bring the BD up to the boiling point of water to dry it. It will dry at room temperature. At 130 degrees it will dry faster, and since you have a great way to bring it to that temp, it will dry nicely.
Here’s how I dry it: I have a separate wash tank (from the processor). It is an open top 55 gallon drum. My batch size is 45 gallons. After washing the BD, I merely circulate it by pumping from the bottom of the wash tank and let it fall through the air back to the top. Sometimes with a fan blowing over it, sometimes not. It will dry crystal clear in a few hours. Even in high relative humidity. If I am in a hurry, I will put my heater spear in it to warm it. Usually to no more than 150 degrees F. I tried a shower head one time, but it was pretty messy. Misted the BD too much and caused a BD film on things. My nozzle now is just a ½ inch pipe elbow. You can see a sample of my end product in my posting called ‘two pipe port and heater spear’. HTH

I have lots of heat available, but here in middle Tennessee it gets quite humid. In the summer you sweat, but it doesn't evaporate and cool you off. When I traven to Folsom California in the summer it is 104+ but the humidity is low. The sweat evaporates and cools you. I'm worried that I will have the same trouble trying to dry BD. I guess I could heat the air that is blown across the top of the barrel. That would lower the RH and allow it to pick up more water.
-Jim

It's called a flash evaporator. Check out the SVO side of this forum and see Tim C Cook's thread on his flash evaporator... whcih they're using to dewater oil, but can be used for biodiesel also without risk of oxidising it.

mark

I am a newbi to the biodiesel process and was wondering if anyone could explain the following phenomenon. I went through the process of making a small blender batch; titration (only 1 gram needed), blend 25% methanol, shake wash with 50% water. I ended up with a cloudy mixture resembling wheat beer. Two weeks later it was still cloudy and I decided to see what the gelling properties were at low temperatures. I put the sample in the freezer and forgot about it. The next day it was solid (looked like lard) so I left it on the window sill to warm up. When I next looked at it it was crystal clear with some white sediment on the bottom of the jar. Any thoughts on how the phase change created the separation?

Tod

I am working on the vacume pump idea already. It is the best way.
If you dry it in the air you will not get the water out. Some will come out but if you were to sent it to a lab, it would be out rageousely high in water content. I work in refrigeration and started a oil recycling program at work. We were using $3000.00 of oil a month. Just the oil sitting in a drum with a 3" bung opening, the oil would get enough water to deam it saturated. Granted a diesel is not as critical as a 800 HP NH3 compressor but it is still damaging. When I boiled off the water, it took 250 deg F for 10 hours to get the water out.
That is a lot of energy. Placing it in a vacume over night removed it as well. A vaccume pump can be purchased on Ebay for a $100. The container is the problem. Thin drums will collaps. And doing one apple cider jar at a time is insane. But a few propane tanks linked together works fine, or an old air compressor is ideal. I am getting a 400 gallon air tank to batch in. Paint it flat black, place in the sun and vaccume away.
The cleaner it is, the longer your car will run.

Would the Accusorb beads work in a drying capacity after washing using the generally accepted processes?

I will post as soon as I find out. I have "DRI-Rite" which asorbs water then one has to bake in solar oven (Cheaper) at 400 degrees for 20 minutes. Then it is good again. First I am waiting for my triple beam scale to arrive, so I can do the "boil out" test, and see how much water I have.

Has anyone had success using hydrogenated oil?? I see where it says to dry biodiesel do this and that, but with hydro I can't make bio as it turns to goop first. Any ideas?? I have a couple of barrels of the stuff.