OK. Looks like I need to go buy some bromophenol blue then.
What exactly is the ASTM amount of allowable soap content? I'm willing to bet most, if not all of my batches weren't up to spec. I've run probably 120 gallons through my Ford and my 4runner and I never even did a 50/50 test on all that. I washed it a bunch and then put the "orange juice" into my dryer. After it was dry it was absolutely crystal clear so I just assumed it was clean. This last bit of dirty bio that I demethed came out crystal clear too and that made me realize that the stuff I've done over the last month probably dirty too.
Oh well, part of the learning experience I guess!
'clear & bright' is generally a sign of clean BD.... at room temperature. As long as where you operate on BD is mostly warm to hot like Oz then it's probably OK without further testing.
If you live where it snows, then more specific testing is warranted for trouble-free operation. My qualitative test for soap/glycerol is a water-wash test with 1/3 water 2/3 BD, shaken and settled. If the wash water is clear enough to read through when using Rainwater/Snowmelt/Distilled water then the BD is very likely clean enough to pass the quantitative test with Bromophenol blue. I run initial tests with 'tap water' till it shows clear then with RSD water.
The two most harmful contaminants are soap/glycerol and water. I do a Carbide Manometer water test as the final assurance of good quality fuel.
The test is: "Bright and Clear at the lowest temperature it is likely to experience "
This is a test for water.
Water comes out of solution and into suspension at the biodiesel cools down.
As long as the water stays in solution as the biodiesel cools down then it passes the test.
If the biodiesel starts to turn cloudy as it cools down then it either requires further drying or the biodiesel is starting to go solid.
Do you remember making this observation a few years ago-
""Bright and Clear" isn't a test, it's merely an observation that the water content is likely less than 1%..."
I have never heard of the Bright and Clear Test" being used as a test for soap.
As ouchfoss has discovered, there can be a lot of soap remaining in Bright and Clear biodiesel as indicated by using the Shake-em up test.
I always get a chuckle at how little some people actually know about Australia and the weather in the different locations. "mostly warm to hot" Does not describe the weather in large parts of populated Australia.
This is the shake-um up test which is a test for soap.
After everything I have read about dry wash setups and the ease of use, I decided to build one and couldn't be happier! It was actually pretty easy to build and install and I'm surprised more people don't use that as their soap cleaning process. All I have is a six foot piece of 4" black ABS plastic pipe with reducers to 3/4" glued on my each end. I have some really small stainless mesh in both ends and I have it filled up with walnut that is half fine sawdust and half dado blade shavings from a table saw. At the moment, both ends are glued shut so I figure when I need to change out the wood shavings for new stuff, I will just cut one end off close and then just reglue it with a coupling ( essentially, it will cost me like $2.00 to change it)! I have a drum elevated 6 feet high and just gravity feed into a lower clean barrel. So far, I have done about 50 gallons at a rate of like 2-3 gallons an hour and with one pass, the shakem-up test was crystal clear!
This makes the process so much simpler and less time consuming. Thanks for all the help everyone!
It can certainly be easier ouchfoss, but also can have it's own problems. What type of media are you using, presumably you are de-mething before the dry wash.
Yes, dry-washing is easy and efficient. I am not actually sure why some people continue with water washing.
I found that once I changed from water washing to dry washing the "sacrificial" inline filter I have installed in front of the car's main fuel filter lasts much longer.
I can only speak for myself, but it's not really any mystery. Water washing is cheap, easy, effective, fast...using what for most of us is a widely available resource. I could go on.
Rather than worry about how many passes/washes or what ratio of water to fuel to use, I built a very simple unattended continuous-flow setup. After good settling and draining of the glycerin layer, I transfer the unfinished fuel to my wash barrel. It has six or eight fine-mist spray heads at the top, and it automatically drains from the bottom so that the total volume in the barrel stays constant. When the draining water runs clear, the fuel is ready for drying. I can only estimate, but I bet my water usage does not exceed my fuel volume -- I surely never noticed a bump in my municipal water bill. That was all before I had an unmetered well.
If you noticed a significant and consistent difference in filter life after changing your methods, I would hazard a guess that your water washing was simply inadequate for your fuel at the time. I'm not saying water washing is better than dry-wash media or anything else people do -- just that it makes a lot of sense in circumstances like mine, which I suspect are pretty common. On the two or three occasions that I had my fuel tested, it met ASTM specs, so it's perfectly possible to make good fuel using old-school methods.
The old ways are not necessarily the best ways.
Where I live water is neither free nor a widely available resource- so far the air I bubble through the biodiesel and the gravity that drops the glycerine from my biodiesel is
Not to mention the HUGE savings in water and waste water disposal.
Dgs,I am using a hardwood called butternut which is a type of walnut. My dad has a small lumber mill and he's had some in the corner drying for the last year. Took me about 6 or 7 board feet to fill my dry wash. And yes, the bio is demethed before it goes thru the media.
I do somewhat understand why people use the water wash method being that water is obviously available anywhere and in some cases like mine, water is free and you have an abundance of it. Part of the reason I went with water wash first was because I didnt want to add any more money to the cost of making bio using lots of expensive piping, pumps or a media that requires changing very often and that was my first impression before doing more research on it. The entire cost of my column is right under $40 and I have an endless supply of media (wood sawdust and shavings) so I think it was a small investment that will pay off really quick with the amount of time saved in making the bio.
Dukegrad98, I was thinking of building something similar to your setup using a float that keeps the liquid level constant in the wash tank but because of my problem with soft water, I think I would have still had a problem with emulsions without having to add something like salt to the mix.
Thanks for the reply ouchfoss.
Water washing can have one big advantage over dry methods. The monoglycerides can be emulsified and removed, separated and re-processed.
All biodiesel contains monoglycerides. If the bio is not fully converted ( ok, lets say fails 3/27) the mono's can be considerable and if this is the case so will be the bound glycerine.
Over spec for astm?
On the other hand, if you water wash the biodiesel you then have to remove the water.
If you want biodiesel that passes the 3/27 test, make sure to test it BEFORE "washing".
That way you can reprocess if necessary before you start washing.
Water Washing is NOT the method to use to fix biodiesel that does not pass the 3/27 test.
If there are excessive monoglycerides in the biodiesel there will also be diglycerides and possible triglycerides present too. The monoglycerides might wash out with the emulsion, but then again they might not.
If the monoglycerides do not wash out, the Monoglycerides will hold onto water and it will be difficult to dry the biodiesel. I suspect that was where my water washed biodiesel caused problems with the pre-filter.
If you do not put water in your biodiesel, you will have very little water in your biodiesel to worry about.
Not sure what you mean by "over spec for ASTM"This message has been edited. Last edited by: Tilly,
You're overthinking the drain system. Just drain from the bottom, but run the drain pipe vertically up to the level you want to maintain in the barrel. Voila, no overflows or overdrains. I used about $3 worth of 3/4" PVC pipe and elbows to accomplish it on my wash barrel. The barrel itself is just an upside-down 55-gallon HDPE drum, even using the original threaded bung/cap to tie in the drain piping -- the top (original bottom) has the spray heads, driven by water pressure from the municipal system or the well pressure tank. No pumps, no switches, etc. (It's all basically modeled on the same design I use to maintain a constant level in my spring fed pond, less the pond's secondary siphon drain which maintains level during flood rains.)
Plenty of us have found that the biggest key to avoiding emulsions is to have your process right in the first place, before washing -- titrating correctly to avoid using excess catalyst (which will make a soapy mess when combined with oil/fuel/water), and a good separation/removal of the glycerin layer before washing for the same reason.
Tilly, I definitely understand that water is not so plentiful everywhere in the world. Just as the old methods are not always subjectively best, the new methods are not always necessary.
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