I would like to ask what different methods people on this list are using to wash their biodiesel?

I usually use a fine mist/spray over the top of my biodiesel and up until now I have used water at approx 50% of the volume of the biodiesel, and usually wash two or three times before drying, which I do by heating the biodiesel and using a pump to spray it over the inside wall of the tank and then it trickles back down inside.

Now my questions

1.What temp do people have their wash water at? do you use warm or cold water?

2.What amount of water do you use compared to volume of the biodiesel?

3.How many times do you wash your biodiesel?

Chug

1. I usually heat the BD not the water. I heat the BD to about 125 F.
2. I use about 1/3 water +/-
3. First time for two hours (bubbling) let sit overnight. Second time for 4 hours and let sit for 8 + hours. Third time for 8 hours and let sit for 8 + hours. Each time has fresh water. I don't have any idea water the acid level of my water is - but - it comes out well.
BTW - I let the BD sit overnight in the wash station before I start the wash cycle - don't know if this helps - but I've got time.

I use a standpipe system so that I can mist wash continuously (I use an inexpensive garden hose timer to control the wash) with the overflow going into a holding tank (I don't have easy access to a drain). That way it can be done un-attended.

Usually set the timer for an interval that will allow the mist wash to use about three times in water what the volume of the BD is.

ReM

I mistwash for a few gallons and then bubblewash. I religiously re-use the wash water for a 'next batch' one step bck in the process. I also use really nice oil, so there's less soap. This all lets me use as little as 1/4 gallon of fresh water to every gallon of biodiesle- more galons of water actually pass through this fuel, but it's all re-used from the past couple of batches and only about 1/4 or 1/3 of it is fresh water each time. I bubble longer at the very end and usually it clears (summertime temps) in a day or so from just sitting (over the last water)

thanks for the replies guys n gals

but now more questions if I may?

SENIOR
you wrote

'I let the BD sit overnight in the wash station before I start the wash cycle'

Is this just the bidiesel or is there water below it?

REM

Do you use warm or cold water?
and what do you mean by 'the overflow going into a holding tank'?

GM
you wrote
'I religiously re-use the wash water for a 'next batch' one step bck in the process'

Could you elaborate please?
and do you use warm or cold water?



I was thinking of using an electric power shower on a timer to spray/mist enough water(not sure if it should be hot or cold though) onto the biodiesel to wash it in one session.


Is there any advantage/disadvantage that anyone can see to this or is it better to do it in seperate sessions and allowing the water to settle out in between washes?

Cheers
Chug

Chug asked--

Do you use warm or cold water?

Cold

and what do you mean by 'the overflow going into a holding tank'?

I use a stand-pipe system so that I can mist wash continuously w/o the wash tank overflowing. Because I am using NaOh right now I don't just let the output of the wash tank flow into the yard and kill the grass. And because it is physically not possible for me to drain directly into the sewage system I catch the wash water in a 100 gal Rubbermaid stock tank (about $60). This also serves as my spill containment device as both the processor and wash tanks sit on top of it. I keep the wash water unil I have time to dispose of it which I do by way of a long hose and pump.

ReM

Yes, I go ahead and load the water underneath the BD (gently) and set my timer to come on at about 5 AM. When I get home that afternoon - its done - I drain and start the next cycle. Due to my jumping in with both feet before I did any reading - I purchased items that were more expensive than I could have gotten away with. i.e. I bought a drum heating band - though it is much safer than installing a heating element - it is condierably more expensive. When I set the timer - I set the heat at or about 125 F. Its been my experience that this heat does help. Maybe not - but I think it does.

I use what is considered very bad oil. To process the batch, I use NaOH at a rate of 11 to 12 grams/liter. That is how bad this stuff is. Anyways my wash process starts with anywhere from 5 to 10 gallons of biodiesel and I use 5 gallons of water all at room temperature (60 degrees F). The first 5 gallons of water I gently pour into the biodiesel tank (with just 5 to 10 gallons of biodiesel). I let it settle overnight and drain out the water. I add five gallons of fresh water back into the biodiesel and start bubble washing. I bubble wash for about two hours and drain it again after settling overnight. Adding water for the third time I bubble wash for 4 or so hours and drain it again after settling overnight. Adding water again for the fourth time, I bubble wash for 8 or more hours. At this time if the water is not clear after washing I do it all again. If the water is clear, I drain the water and let the biodiesel settle for several days (as water still drops out of biodiesel). I transfer the biodiesel into fuel cans ready for use when I need it. I do take my time at washing. It is the best way I found for bad oil (in which I have lots of).

Regards,

HODiesel

Chug,

I usually do two (sometimes three) mist washes, all with a garden sprayer, and all with hot biodiesel and water. I can't stress enough how advantageous it is to keep everything hot, as it will prevent emulsions from forming even with the worst batches. The first wash is without agitation. It turns my translucent (heretofore unwashed) biodiesel opaque. The second and third washes are aided by air agitation, which temporarily homogenizes the water and biodiesel. After settling for maybe 30 minutes, the soapy water is ready to drain, leaving behind a much darker biodiesel. Drying with some heat and compressed air then makes it crystal clear. From there I filter it and either transfer it directly to my vehicle, or to storage for later use. All of this is accomplished over the course of two days to ensure the best separation between water and biodiesel, but it could probably be accomplished within one day. Each wash is usually about 1/3 the volume of biodiesel, although I don't obsess over it. I just make sure my tank doesn't overflow .

OK,
I used to bubble wash with hot water. I would drain the glycerin, and transfer the unwashed to the washing drum, add 10 gallons of water, drop in my stone and let it bubble overnight. I have a heat spear that is in the water layer, and keeps things hot. My last three batches however, I tried the glycerin/5% water pre-wash. I was a little worried about making an emulsion because I process with a gear pump, very violent. Great for getting the conversion done quickly (I mix for an hour), but I wasn't sure how it would handle water in the mix. So I made my 45 gallon batch, and drew off a couple liters, put it in a milk jug, (sorry no royalties Tilly) added water and shook as hard as I could for a couple minutes. It did not emulsify. Encouraged, I added the water to the processor and turned on the pump. Mixed for a half an hour and shut it down to settle. No emulsion! The glycerin and water settled quickly (I drained it off after an hours settling) then transfered the BD to the wash tank and bubble washed as usual. water was clear on 2nd wash. It's great! I highly recommend the pre-wash. On my last batch, I took half of it, put water under the BD, and pumped the water from the bottom of the wash tank and sprayed back into the top of the BD. This would be my first wash (after the pre-wash)Very violent, like turning on a garden hose over the BD. The water turned white in less than a minute! I could not believe how quickly this method removed the soap! And didn't form an emulsion! I drained the water, and dried the BD. BTW I dry it the same way, eg. warm BD circulated and sprayed back into the top of the wash tank, hitting the pipe of the heat spear, with a fan blowing over it. Dries crystal clear in an hour and stays that way even when it cools down. It's great!

Joe_M, just tried this method of prewash, I was also worried about emulsion as my pump really goes to town and churns everything up. No emulsion!

THe question I have is this: Due to time constraints, I added the 5% water, ran the pump for about 20 minutes, let settle for an hour, drained off the glycerine. I let the bio sit in my processor all night after drwaing off a small smple for "viewing".

Is it normal to have cloudy bio at this stage? No it is definetely not an emulsion, just looks like more clouding than usual at this stage.

Not able to wash untill this eve, so I guess I will find out for sure then.

Even though it is cloudy, it is some of the best looking bio I have made yet (extremely light in color), a combination of low titration oil, excellent mixing, and optimal heat. Untill recently, I had none of these, everything was just enough to get by, but my processor is now complete and operational.

It's nice to have a decent processor, I have finally graduated from the bucket brigade. Thank, Kevin

kevin

yes I find the biodiesel is cloudier when using a glyc wash/prewash than when not, but at the end of the day with drying it is clear.

I now glyc wash for 15 mins, then after settling/draining of glyc/water I hosepipe spray over about the same quantity of warm water as there is biodiesel then settle/drain off wash water and dry, only the glyc wash and one more wash compared to three or four washes I used to do!

chug

Kevin,
Yep, cloudy after the glyc. wash, but clears up well.

Chug,
Yeah, me too! The glyc pre wash then one more wash and then dry. It's great! I gotta get a bigger tank! Two hundred dollars for that 500 gallon air tank was not bad, but I'm too cheap- it went to someone else. Oh well, I'll eventually find the 375 gallon tank that I'm looking for. That would be cool, to use an entire 55 gallon drum of MeOH in one batch. Add the NaOH to the drum, and that would be the methoxide mixing tank. Nice!

quote:

Add the NaOH to the drum, and that would be the methoxide mixing tank. Nice!

except that it won't fit.

Well, thanks for the input gentlemen, I am washing as we speak and it is cleaning up nicely .

Looks like I will get similiar results with the wash as you are reporting.

Just got to thinking, if you have an oil that titrates high, then wouldn't you have more of a chance of that 5% prewash causing an emulsion?

I get some oil that titrates low, and some that titrates really high, I have been mixing the two when I can, but sometimes I have to use what I have.

Thanks again, Kevin

Tempted by good reports from pre-washing. The downside for me would be water contaminating the glyc., so rendering it useless as heating fuel. On the other hand, as I always use 2-stage base-base, the larger part of the glyc is from stage 1 and would be dry, while the stage 2 glyc used in the pre-wash would be scrapped.
Question: what would be the effect of having much less glyc in the mix during a 5% water pre-wash?

David

the first time I tried the glyc wash/prewash I must have been high on methanol as I thought it was 25% water...oops, but it still worked ok, I think this would be similar situation to what you are asking with less glyc present, I guess there is only one way to find out--try it and let us know.

Chug

quote:

Originally posted by neutral:

quote:

Add the NaOH to the drum, and that would be the methoxide mixing tank. Nice!

except that it won't fit.

Well, for 300 gallons of the oil I get, I would need about 2 3/4 gallons of space for the NaOH. (6000 grams) A 55 gallon drum is not full to the top, and I would not have a problem with removing 3 gallons from the drum, dissolving the NaOH, then adding the 3 gallons back to the drum as the methoxide is being sucked (or pumped) into the processor. I have visions of using that weird suction/discharge combo fitting that I made to stir the methoxide. It works great for processing a drum of oil BTW.

I'd like to ask if the washing methods for home-made biodiesel are also applicable to large-scale manufacturing? Will there be any problems if I try to use mist washing for washing large batches of biodiesel? I would appreciate any advice you guys could give me.... you could send an email to rowzmari_17@yahoo.com or ps_che05@yahoo.comps_che05@yahoo.com