Thanks BC, I had a go last night, warmed it up and hey presto the BD became a beautiful clear solution and droplets of water appeared on the bottom.
I let it sit for a while then I decanted the BD into containers ready for the tank. After cooling I went to put it in, only to discover it was cloudy again. So I warmed it up and you guessed it - it went clear again! This time however no water dropped out.
I solved the problem by adding it to the tank warm! It will make a 20% BD fuel mix for a first trial. I primarily wanted to get it in to clean the fuel lines before I change the fuel filter!
A small start.....
It could be that you still have some water in the bd if you leave it overnight uncovered you might find that it will clear on its own again bd WILL absorb water from the air AND will also release water to the atmosphear depending on the water content of the day/night air
I would advise to fully dry bd by heating to 120d C untill steam stops rising from the bd then allow to cool befor putting into your fuel tank
Your observation that washed BD can be cleared by warming only to become hazy again on cooling is standard normal behaviour. Warm BD can hold more water in true solution than when cold, and when cooled the water comes out in extremely fine particles, so fine that settling takes days or weeks.
Quicker than settling is exposure of the surface of the BD to air. The water will slowly evaporate and the BD will become completely clear.
Don't think that the BD is now dry however. How dry it gets will depend on temperature, humidity and length of exposure. It may still go hazy if cooled further.
Although the question is by no means settled there is reason to suspect that hazy BD may permit corrosion while clear BD may not. If this was a worry it might be wise to dry the BD further by heating as Biocruiser suggests. My view however is that if there is a danger that cooling might cause corrosion it will occur only in the tank, as by the time the BD gets to the motor it will be warm again and clear.
To check out the dryness of your BD place a sample in a clear sealed jar and cool it. Note the temperature you can get down to before it becomes hazy. If very dry you will not see water haze but instead will observe the "cloud point" at which crystals start to form. This looks different, aptly described by Tilly as "wispy" and "smoke-like", unlike water haze, which, as you have already seen, is uniform throughout.
[This message was edited by neutral on 18 December 2001 at 12:22 AM.]
Paul R and others,
Have had trouble with hazy BD in the past.
Decanted, heat dried BD would be crystal clear when warm but when cooled to room temp overnight it would become hazy.
Beef Tallow was the culprit. I no longer heat dry. The decanted BD is filtered cold. The beef tallow emulsion is retained in the filter paper. (Previously heating the decanted mix would dissolve the BD emulsion). Filtrate consists of BD with globule of water in bottom of vessel.
Water separated leaving crystal clear BD. Heat drying this BD yields no further water separation.
I won't say that there is no water in the BD but it remains clear.
have done some more on this as of late and over the past two days have repeated
using tallow as the bd base I have done my wash using the MIST system as usual
since it has been reasonably warm here over the past coupla days I have done the following
day 1 I allowed the bd that I had MIST washed to sit over the water overnight, the water was still "IN" the bd as this was slightly discoloured and not clear the next morning I checked it and still the BD wash showing signs of emulsafied water, i ALLOWED THIS TO SIT for a further 3 hours till the sun and heat had their chance to do their bit and the result was clear BD
I drained off the settled water and applnother MIST wash and again allowed this to sit overnight
Again the water was still showing sighns of emulsafication so again I allowed it time and heat again it cleared this time I drained off the water and the BD seperatly
I heat dryed the BD over gas to approx 120d C till no more steam was comming off the BD I now have it cooling off overnight to see wot happens
any one hazzard a guess???
Your observations confirm that water haze can disappear if BD is warmed and will reappear on cooling. While it is possible to dry BD after the first wash sufficiently to prevent haze forming there is no point in this as the amount of water in the haze and in solution is negligible compared with the water added in the second wash. You might as well save time and press on with the second wash, or third wash if needed, before putting effort into drying.
Prolonged settling with exposure to air is good after all washing is completed as it not only allows the water content to be reduced but also allows settling of the high melting point fractions mentioned by PaulG above.
This is becoming interesting... is BD hydroscopic like Dino Diesel?
Here in Brisbane with the high summer humidity is it possible that the BD would absorb more moisture from the air than the almost dry state of the BD if left out to "air"?
Every question seems to generate three more!
Well from basic esterology, we know that esters are primarily insoluble in water, but in this case it doesnt seem so.
i too have noticed this haze, which i believe it to be the water haze which you speak of as it is uniform throughout the BD.
I will experiment by placing a sample in my food dehydrator and see if it clears up that way (with the lid off of coarse). Could save a lot in power and time since these things use about 2c worth of electricity an hour to run.
I have no figures on it but would expect BD to be more hygroscopic than diesel because of the oxygen in the molecule. And yes, BD will equilibrate at a higher moisture level in a humid climate, but remembering the comment earlier that even if haze appears in the tank after a cold night this is not likely to be a problem because it will disappear when it feels the warmth of the motor. So I wouldn't bother using heat to dry the BD unless in a hurry, just expose it to air preferably in a shallow container.
What is a food dehydrator?
ME thinks you mis-understood I not dry after the first wash for as you point out it would be pointless
since my last post the BD has remained clear overnight with no significant haze that my pore old eyes can seea
BC blind pew fan club
Well ours is a wooden box with a thermostat and a small fan. You put whatever food you want into it, like fruit, set the thermostat to about 45 degrees. shut the door and away you go.
Great dried fruit that will keep all year.
My mother also dries sliced lambs fry which she uses as a substitute for smackos whilst training our dog.
A slight refinement to the system.
The new drink caps with the click taps in them make for easy seperation after settling - just hold the bottles upside down.
Think Ill look around for a second hand Paint mixer from a paint shop - the kind that shakes the can - some of them take a 20L drum and should give the kind of mixing needed. They do a real job on paint in a couple of seconds that takes forever with a propellor mixer
I agree john, if you have access to a paint shaker it should be an ideal biodiesel mixer.
Tilly SBC/IBA paradise div.
If the #2 pencil is so popular, why is it still #2?
JohnH and Tilly,
Local hardware store had homemade paint can mixer.
It was based on an old Singer treddle sewing machine.
Sewing machine head was replaced by electric motor which drove treddle platform.
Should work well for BD.
This is a remarkably long thread on the art of making BD. There is not much missing from it. One small point worth making is that dissolving the NaOH in methanol for small batches is best done in a glass bottle with a well sealing cap. Glass won't be dissolved by the NaOH no matter how concentrated, unlike some plastics, and will stand the slight rise in pressure that comes from the warming effect. A well sealed bottle permits the shaking and swirling needed with no risk of spilling or inhaling vapour as occurs with an open vessel.
With regard to the container destruction experienced with mixing the NaOH... I have been mixing in a glass measuring cup so far, but what about using a glass blender? The impeller is metal, stainless steel I believe, and there is a rubber gasket. Am I in for any problems using this?
As far as the Alcohol / Oil mixing buckets, what kind of plasic can withstand the NaOH? I have so far lost 2 2-liter bottles well AFTER the oil was removed, it seems even the slightest lye eats throught the bottles. Maybe b/c the US is using "PETE #1" recycle-able bottles, the plastic is weaker? I was planning on using some large storage tubs that are marked "PP #5" plastic, nice and thick, 60 quart capacity. Think those will work OK?
I don't know where to get any large glass tubs, nor do I like the idea of using them, as I can't cut them to install a spigot.
On another note: My VW TDI has an inline water / fuel separator for the Dino-D I have been feeding it, will that continue to work for separating the water from the Bio-D I make? That would reduce a lot of my headaches.
"Errors have been made. Others will be blamed."
Another small point about the advantage of using a sealed glass bottle for dissolving the NaOH in methanol is the fact that there will be no loss of methanol by evaporation. Puzzling disappointing results are sometimes caused by the unnoticed loss of methanol.
Yes Geordie a blender with a well fitting gasket should do the trick. It would be quick.
By the way I don't know why people keep saying "don't use your blender for food again". It is just one more example of the way in which the BD culture has grown up without looking into all the facts.
Both NaOH and methanol are completely water soluble and wash out more easily than just about anything you can think of. Furthermore the methanol, if left, would evaporate and even the NaOH, if left, would eventually turn into Na2CO3 which is washing soda and harmless. The film of NaOH which could be left would be so thin that one could combine it with the next drink anyway. The pH adjustment it would cause would be hard to measure.
Ok, so I can use a blender. That doesn't mean I WANT to ever use it for food again...
But what about the plastics? Anyone have any opinions on the survivability of the "PP #5" plastic? I'm guessing the PP stands for PolyPropylene, and I'm doing a durability test on a small box made from it now. If this test isn't needed, could someone LMK?
Otherwise, more results tomorrow.
"Errors have been made. Others will be blamed."
Some basic information on plastics identification and recycling.
Sometimes the link is a bit slow. An alternative path is:
go to "Services", then"Waste Management & Recycling, then scroll down to
"Publications available", then go to "Factsheets Recycling" and finally to
More detailed Information at Mid Michigan branch of Society of Plastic
Some great teaching resources here.
Properties of Plastics.
The CRC Handbook of Chemistry and Physics 49th Edition 1968-1969, has a couple of tables on plastics.
1/. Trade Names, Composition and Manufacturers of Some Plastics.
2/. Properties of Commercial Plastics
The latter gives data for Electrical Properties, Mechanical Properties, Thermal Properties, Chemical Resistance and Miscellaneous Properties.
a listing of some of the Chemical resistance data appears below.
Mineral acids weak,
Mineral acids strong,
Cellulose Acetate, soft and hard.
fair to gd,poor,poor,very poor,poor,poor,fair to good
Cellulose Acetate Butyrate, soft and hard
good,fair to good,good,poor,poor,poor,good
very good,poor,no effect,no effect,good,good,good
Polyethylene, low density
good,good,good,good,excellent to poor,excellent to poor,good.
Polyethylene, medium and high density
excellent,excellent,excellent,excellent,excellent to poor,excellent to poor,excellent(HD good).
good,fair to good,good,poor,.........,dissolves, good.
excellent,excellent,excell to good, excellent to good, excellent to good, excellent to good, good.
excellent, excellent, excellent,good, gd <80 degC, gd<80 degC, gd<80 degC.
excellent, excellent, excellent, excellent,excellent, poor, fair to poor.
excellent, good to excellent, excellent, good to excellent,good,dissolves, good to excellent.
Polytetrafluoro ethylene, unmodified.
excellent, excellent, excellent,excellent,excellent, excellent,excellent.
Polytrifluorochloro ethylene, unmodified.
Polyvinylchloride and Vinylchloride acetate, unmodified, rigid.
excellent, good to excellent, excellent, good , excellent, poor,excellent
Polyvinylchloride and Vinylchloride acetate, plasticised, non rigid.
fair to good,fair to good , poor to fair,fair to good, fair, poor, poor.
excellent,fair to good,excellent, excellent,excellent, .......,excellent
Melamine-Formaldehyde, a-Cellulose filled.
good, poor, good, poor, good, good, good.
Melamine-Formaldehyde, mineral filled, (electrical).,
fair, poor, fair, poor, good, good, good.
variable, poor, variable, poor, good,fair to good ,good.
Phenol-Formaldehyde, cellulose filled.
variable, poor , variable, poor, good to excellent, fair to good, excellent.
Phenol-Formaldehyde, unfilled cast phenolic,mechanical and chemical grade.
fair to good, poor to good, poor to good, poor, good to excellent, fair to good, excellent.
Polyester (Styrene-Alkyd). Glassfibre mat reinforced.
good, poor, good, poor, poor, good, good.
Silicones, mineral filled.
fair to good, poor to good, fair, poor, poor , .........., good.
Urea Formaldehyde a-Cellulose filled.
poor, poor, fair, poor, good,good, ........
Acrylonitrile-Butadiene-Styrene (ABS) high heat resistant.
fair, poor, poor, poor, good, good, good.
Alkyd resins, Synthetic fibre filled.
good, fair,good, fair ,fair to good,fair to good, fair to good.
There are many types of plastic in common use. Plastic must be sorted by type for recycling since each type melts at a different temperature and has different properties. The plastics industry has developed an identification system (or identification codes) to label the different types of plastic. The identification system divides plastic into seven distinct types and uses a number code generally found on the bottom of containers. The following table explains the seven code system.
Plastic #1: Polyethylene Terephthalate (PET)
Common uses: 2 liter soda bottles, cooking oil bottles, peanut butter jars. This is the most widely recycled plastic and the only one with a redemption value under the California "Bottle Bill." Many recycling programs and centers request that you remove caps and flatten the bottles.
Plastic #2: High Density Polyethylene (HDPE)
Common uses: detergent bottles, milk jugs, grocery bags. Most curbside recycling programs accept rigid narrow neck containers. Contact your curbside recycling service provider about whether they take plastic #2 and if containers need to be sorted by color.
Plastic #3: Polyvinyl Chloride (PVC)
Common uses: plastic pipes, outdoor furniture, shrink wrap, water bottles, salad dressing and liquid detergent containers. Recycling centers almost never take #3 plastic. Look for alternatives whenever possible.
Plastic #4: Low Density Polyethylene (LDPE)
Common uses: dry cleaning bags, produce bags, trash can liners, food storage containers. Some stores that accept HDPE (#2) also accept LDPE (#4) bags.
Plastic #5: Polypropylene (PP)
Common uses: aerosol caps, drinking straws. Recycling centers almost never take #5 plastic. Look for alternatives whenever possible.
Plastic #6: Polystyrene (PS)
Common uses: packaging pellets or "Styrofoam peanuts," cups, plastic tableware, meat trays, to-go "clam shell" containers. Many shipping/packaging stores will accept polystyrene peanuts and other packaging materials for reuse. Cups, meat trays, and other containers that have come in contact food are more difficult to recycle. If you have large quantities call the Alameda County Recycling Hotline.
Plastic #7: Other
Common uses: certain kinds of food containers and Tupperware. This plastic category, as its name of "other" implies, is any plastic other than the named #1-#6 plastic types. These containers can be any of the several different types of plastic polymers.
Hope this is useful, squarepeg.
[This message was edited by PaulG on 15 May 2002 at 07:34 AM.]
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