How high up does the stand pipe need to be? I will be building a wash tank based on the design located at http://www.utahbiodiesel.org/photogallery/processors/20041127graydonswashtank.

Basically what I need is instructions on how to use the thing. How long do the misters need to be turned on, when do I turn the bubbler on, etc.

This message has been edited. Last edited by: Graydon Blair,

If you're using a 55 Gallon Drum, the height I've been using is 8". This allows for about 15 gallons of water to sit below the standpipe.

Instructions For Using A Wash Tank:
1- Transfer Biodiesel into Wash Tank
2- Turn on Heater & heat the biodiesel to at least 80 deg F.
3- Once it's to temperature turn on the misters.
NOTE: Don't mist too agressive to start with. You want a nice, light mist, preferrably somewhat above the Biodiesel.
4- Mist until you fill the tank w/ washwater up to the stand-pipe
5- Turn off the misters & let it sit for 3-4 hours to let the water settle.
6- Drain off the first wash water using the non-standpipe opening
7- Mist again, but this time using a more aggressive mist up to the standpipe level again
8- Let it sit again for 3-4 hours
9- Leaving the wash water in the tank, begin a VERY LIGHT bubble. Bubble too hard and you're going to get emulsion.
10- Bubble like this for about 8 hours
11- Turn the bubbler off.
12- Let it sit for about 3-4 hours.
13- Turn Bubbler back on, only this time more aggressive for another 8 hours
14- Turn off bubbler & check to see if it's done.

Way to check if the Biodiesel is completely washed:
1- Fill a small, clear container about half way with washed biodiesel from the wash tank

2- Fill the container the rest of the way with water.


3- Shake up the container.


4- It should then look like a sort of yellow milk-shake


5- Stick it somewhere and let it begin settling


6- The water should begin to settle out from the biodiesel.

More Settling


7- Once it's done, it should look like this:


This took about 15-20 minutes to settle out on a nice warm day. Depending on temperature and humidity and a bunch of other factors, your settling time may take longer.

Notice the nice, clear water on the bottom though. If your water doesn't come out clear, it means you need to do more washing.

The Biodiesel doesn't go completely clear at this stage though, it's still a bit cloudy but the water on the bottom is nice & clear.

Hope that helps.

Pictures came from a day I spent w/ Jack Jones of Riverstones Biodiesel.
-Graydon

This message has been edited. Last edited by: Graydon Blair,

I would recommend a stand pipe height that is at about 10 gallons. That's the height of the stand pipe in the washer I built and it seams to
work really well. I think it is a 6" pipe.

I don't usually time my mists. I just turn the mister on and check the water level every once in a while. When the water level is at about 10
gallons I turn off the mister. By the way, I do not bubble while the mister is on and I don't recommend bubbling during the mist, it's likely to be too agressive.

After misting the water into the washer I usually let it sit for maybe 5 minutes after turning off the mister. At this point all I'm looking for is a nice distinct layering. i.e. a definite water layer, maybe a small layer of scum (maybe 1 inch thick max), then a distict biodiesel layer. If the "scum" layer is much bigger then 1 inch then you probably have an
emulsion and need to think about breaking that emulsion before moving on.

Graydon, at setp 10, you can usually tell a lot sooner then 8 hours if you can turn the bubbles up to be aggresive. I usually turn the bubbles on low and watch for any signs of emulsion, like
white slimmy maonaisse type stuff rising up with the bubbles, or an actual emulsion layer building up between the water and the bioidesel. The slimmy stuff rising up with the bubbles happens immediately. The emulsion layer will occur within an hour or two. If I see no signs of emulsion then I crank the bubbler up and let it go for about
24 hours. If I see signs of emulsion then I drain the water, do another mist, and then bubble.

-Jack
http://riodiesel.com/

I was wondering if you could use your wash tank as the settling tank(empty processor after about 1 hr of mixing) After 8 or so hrs of settling, drain glycerin and start your wash then. If this could be done, you could make serveral batches in a day and have a separate wash tank for each batch. Just thinking about it though, one would probably have to put a lid on the tanks especially after coming out of the processor. Very new to this biodiesel thing but am eager to make it happen

Hi Dan,

the biggest issue is that it's hard to completely drain all glycerine out of flat-bottom drums- and glycerine byproduct can cause emulsions during washing because of all the soap it contains. So it's best to have a separate settling tank and a wash tank that is only used for washing and drying.

I actually have a setup like this:

-processor which can be a settling tank also if I feel like it
-settling tank for the times I want to do two batches in one day
-two drum based wash tanks so I can wash and dry those two batches while making two more (the washings usually longer than the processing/settling of glycerine)
-another larger dome-bottom tank which I sometimes use for both settling, washing, drying, and storage of the finished fuel if I'm really going nuts making batches (I got in the habit of storing up a month's worth of oil and doing all the processing/washing in one "sitting")

Mark

How long is it taking you guys to fill up your wash tanks using the mister? I swear that the Arizona mister that i have is flowing about 1 gallon per hour and my stand pipe is at about 10 gallons.... that's 10 hrs just to fill it to that level! That might just be how long it takes, but that seems like a long time.

I'm currently doing a prewash so i can take out a couple of mistwashes and go straight to the hard agitation and have even as far as sprayed water into the tank on full power on the 'shower' setting (not to powerful, but still MUCH more agitating than the misters). I was considering getting a more aggressive mister..... maybe a combination that would allow 10gal/hr.

ProjectPurity,

Misting is the best way to get the rest of the methanol out of the biodiesel. Since your using the prewash I would recommend doing the mist wash for a few hours then drain to remove the methanol. After that bubblewashing may be best for you.

Bubblewashing worked great.... i did pretty much what you said the last time i brewed 60L gals (the first time i prewashed) and had no problems.... it's just that i like the idea of the misting/mist heads.... i just need a higher volume spray head i think.

The Foggit heads (ebay) are supposed to be about three times the flow rate as the Arizona mister.

I just started carrying the Fogg-It nozzles now too.


http://www.utahbiodieselsupply.com/washingsupplies.php#foggit

They come in all sorts of flow rates, but I've got em in 1/4 GPM and 1/2 GPM.

People really have said positive things about them. If you use them, as indicated above, just be sure they don't spray too aggressive. Otherwise, you'll be dealing with an emulsification.

I still like the Arizona Mist Kits too.

http://www.utahbiodieselsupply.com/washingsupplies.php#orbit

There's really no "right" or "wrong" way to wash, just as long as you get it clean and you keep from getting an emulsification.

Let the creative juices flow!
-Graydon

Does anyone mist/shower and reuse the water from the bottom of the tank with a pump? Is there some known drawback to this, other than not getting the feeback on how emulsion prone your fuel is from bubbing?

If so, what pump? It seem that I would want to use some low flow pump. Comments?

Andrew

I've not heard of anyone recirculating the wash water. As you wash, the water becomes saturated with soap (which is what you're trying to get rid of), so it's a good idea to get rid of it, otherwise you risk putting what you just washed out back into the biodiesel and possibly causing an emulsion.

-Graydon

Right - But when we bubble we do the same thing - each bubble comes up through the mixed layer which is where all the gunk is. The bubble brings this to the top with the water, right?

I was particularly thinking of using this for the last part of washing when the water and fuel are both already pretty clean. My idea being this way it would only bring slightly soapy water up, rather than the mid layer with the bubbles. I know it works fine that way, but do you think this would also work?

Andrew

It's going to be barrel dependent...
My understanding is the you have 2/3 BD and 1/3 water, plus 18" of clearance on the top for the mising.
So, I would take the total height, subtract 18", then divide the remainder into 3 parts. The height of the standpipe should be at top of the bottom 1/3.
I have always been worried about dumping wash water down the standpipe, which is why I have a tee on the top of my standpipe. It should prevent most water and other contaminants from getting into the standpipe.
But, I also have a question. I found it difficult and time consuming to get the pipe through the bung which I had to cut out with a drill. Wouldn't it be much simpler to just use a 2-inch to 3/4-inch black-pipe bushing?
Ron

I was doing my first wash ever of about 20 gallons in a steel standpipe tank. I mist washed at night, then let it sit overnight, and in the morning I went to drain. I drained what looked like good wash water for maybe 5-7 gallons, and then the wash water got a little bit yellow/brown and opaque, but it wasn't the change of color I was expecting. I was expecting darker, clearer and more orange. So I filled some jars and let them sit, and some of them settled out to more resemble biodiesel.

My question is, is that a 3rd layer, or just what biodiesel looks like if you drain it after the 1st wash? Should I stop draining when I hit that first color change and start a new mist wash? Or should I discard it and keep draining until I get what I expected?

I lost track of a 2" bung plug which had two 3/4" pipe fittings on the inside, allowing two different lengths of standpipe and on the outside the ports were set at and angle so that both pipes could have fittings attached. Who knows where to get this item?

quote:

Originally posted by dfy:
I lost track of a 2" bung plug which had two 3/4" pipe fittings on the inside, allowing two different lengths of standpipe and on the outside the ports were set at and angle so that both pipes could have fittings attached. Who knows where to get this item?

I have run across this one on ebay Item number: 140182057151 there may be other sorces that cost less.