i was wondering how much off the top of a well settled (3 weeks or more) WVO standpipe or cubee is best for blending?
i realize there are many variables but has anyone done any viscosity testing to see when it becomes noticeably thicker? i am using good smelling amber soy from a chinese restaurant.

Generally between 1 and 12 inches of VO in the top of a well settled cubie is clear and dry enough for blending with other diesel fuels. It depends on the type of VO and what was cooked in it.

quote:

Originally posted by john galt:
Generally between 1 and 12 inches of VO in the top of a well settled cubie is clear and dry enough for blending with other diesel fuels. It depends on the type of VO and what was cooked in it.

John,
When you say " dry enough" do you mean it would pass ( or come close to passing) a HPT or do you mean more along the lines of absent of free water, or, is there some other standard you have?

My interpretation of dry oil is that which will pass a HPT but I haven't been able to achieve this by settling alone although it is very effective in lowering the amount of free and dissolved water.

quote:

Originally posted by DCS:
John,
When you say " dry enough" do you mean it would pass ( or come close to passing) a HPT or do you mean more along the lines of absent of free water, or, is there some other standard you have?

My interpretation of dry oil is that which will pass a HPT but I haven't been able to achieve this by settling alone although it is very effective in lowering the amount of free and dissolved water.

"dry enough" is quite subjective, to me it's passing the HPT or about 500ppm, for others "dry enough" is clear when chilled in the fridge. Many variables affect how easy it is to dry UVO including type of oil, what was cooked in it, for how many hours, and then settled for how long at what temperature. I find that cold [<60°F] upflow settling removes the PHO, fats and the water with the canola oil I get from a fish & chips place. I expect that anyone else using that system with that oil would have similar results, someone else might not.

john, your cold up flow process removes *ALL* of your fish fried oils water to the point of passing
the HPT and satisfying your 500ppm requirement? did you do a HPT before any settling could take place
to quantify the difference?

DCS, how long do you setttle your UFO and at what
(stable?) temperature? what kind of (aspect ratio)
containers do you use for settling are they metal
(heat and cool readily upon temperature changes)
or plastic?

has anyone carefully tapped (without disturbing) settled UFO at different depths inch for inch for instance and tested for viscosity at each station?

i am anticipating the top layer would be good for blending, the middle suitable for heated SVO operation and near the bottom best for making B100 with a high energy content.

do you recall any posts on this nature, i have searched but to no avail.

ty,
john

quote:

Originally posted by 1.6D MKI GTI:

DCS, how long do you setttle your UFO and at what
(stable?) temperature? what kind of (aspect ratio)
containers do you use for settling are they metal
(heat and cool readily upon temperature changes)
or plastic?

I have settled oil over 12 Months but my normal turn around time these days is closer to 6.
The oil is settled in 200L drums and IBC's.
Most of the oil in whatever container is out of the sun and shaded if not completely under cover.
I have no problem with convection currents and the oil I take off is completely particle free to the naked eye.

Myself nor any other Vegger I know here has been able to get oil to pass a HPT through settling alone. Some have tried heat wraps on drums, some have put a cubee in the fridge for months on end but the goal of oil dry enough to pass a HPT seems elusive here for whatever reason.
I believe that some people that do get completely dry oil through settling alone live in climates where the oil is frozen one or more times and this may be significant in what they achieve. While temps can hit freezing where I am, it would only be for a few weeks and for a few hours overnight.

I actually find that the oil settles quicker and dries faster in the summer months when it is at a lesser viscosity than in winter. I am always looking to achieve this holy grail of dry oil through settling alone but have come to the conclusion there is more to it than meets the eye.
There is no doubt though settling does reduce the water content in my oil substantially. I have taken samples of the oil when I filled a tank and then tested it again when I pumped it off. The difference before and after is significant.

To get the oil thoroughly dry I built a processor that filters and dries the oil at the same time and I can do 150L batches in 90 min or less. Before I used settling, this same setup took about 3 hours.
I don't bother with up flow settling anymore as adding the oil slowly was a pain for me and the residence time I can achieve with the reserve of oil I have means I achieve the same result anyway.

What I am constantly amazed by is the complexity so many people seem to go to with their filtering and drying setups and the energy they invest in the oil to get it to a finished product when just putting the stuff in drums and leaving it the hell alone for 3 months would get them so much closer to their goal without them having to do a thing.

I see people using several filters of stepped sizes and different complex and expensive setups sucking amounts of power that most homes here aren't even wired for and compare it to what I do and achieve the same outcome. I understand not everyone has room to store large reserves of oil but many people that seem to have the most complex and energy inefficient setups in fact do!

While I'm very happy with the results I get, I suppose there is always a sense of pride at stake that you want to do something better and faster. Whenever I read of someone with a faster drying/ filtering setup than mine, I also see they are sinking huge amounts of energy into the process. If I heated my oil with the power others use, I could easily get it dry in 1/3rd the time or process maybe 5 times the amount of oil in the same period I do now.

While the environmental green aspect is not my biggest motivator for using oil, I often read the process some use that tout the green angle as their prime concern and wonder just how green their fuel really is after it has had so many KW of energy sunk into it.
While I would like to be able to achieve what John does for the merits of that, although I am unable to achieve the energy independence he does, I am happy with my process that uses less than half a KW/H of electricity to dry and filter 150L of oil.

Without the settling process, this simply wouldn't be possible especially with the simple system I have nor would my last set of filters have processed over 2500L of oil before I replaced them only to discover they easily could have gone twice that again!

quote:

...cold up flow process removes *ALL* of your fish fried oils water to the point of passing
the HPT and satisfying your 500ppm requirement? did you do a HPT before any settling could take place
to quantify the difference?

When I first started experimenting with VO fuels years ago I did a lot of moisture tests using the HPT. Retained moisture depends on Type, Temperature, and Time. 'Fresh' used VO in cubies or buckets may have three layers at 'room' temperature 20°C 68°F. There is usually a top layer of clear oil which might HPT with a few bubbles to many bubbles, though no sputtering of free water. A middle layer of creamy consistency and color always tested positive with the HPT, though free water was uncommon. The bottom layer of brown sludge always tested positive and usually had free water. When stored outside at temperatures below 15°C 60°F the middle creamy layer of fats and PHO would thicken and the clear oil layer would reduce. The clear layer became drier and the creamy layer wetter.

I wanted clear dry fuel to blend for winter so I developed a processes to separate the clear and creamy layers. When operated below 15°C the clear oil output is nearly dry, which I occasionally check with a vapor test. Summer operation invariably passes some of the fats and PHO into the storage barrel however they sink to the bottom as soon as the temperature outside is cold enough. VO off the top 3/4s of the storage barrel always tests dry.

I live in a climate where it's below 15°C for most of the year. Three months of 'summer' will produce temperatures above 20°C and to brief extremes in the low 40°C range when the sun is out 24/7. There are also three to four months of hard winter where extremes to -40°C can occur. Water is frozen for about 6 months of the year. When used VO gradually cools and freezes over the winter, then the next spring before the creamy layer starts to melt the clear layer can be quite dry in many cases, depending on what was cooked in it. Nearly all the moisture is in the creamy layer and the bottom sludge.

The best used oil I've found is clear canola [non-hydrogenated] used to cook fresh [non frozen] foods containing minimum animal fat and changed weekly or more often.

The up-flow processor I built is described here:
http://www.burnveg.com/forum/viewtopic.php?t=9
Over the years it's evolved to look a lot like this one:

Simple, easy, cost effective, and most importantly it runs unattended without electricity. Pour 'dirty' oil in the top barrel and walk away. Assuming course that you've checked the storage barrel for room. Alternatively one can place the hose into an empty cubie and pour a full cubie of used VO in the top and leave it to do it's thing. Repeat a few hours later as often as required.

The sludge, PHO and fats are mixed with sawdust and help heat the house, the clear fuel powers the truck.

quote:

Originally posted by john galt:
[QUOTE] 'Fresh' used VO in cubies or buckets may have three layers at 'room' temperature 20°C 68°F. There is usually a top layer of clear oil which might HPT with a few bubbles to many bubbles, though no sputtering of free water.

So John, are you saying that your oil when dried through your settling only process can have a few or more bubbles in a HPT depending on the time of year or is it always able to pass a HPT with no Bubbles whatsoever??

Do you collect from one or sevearal sources and will all the oil you get pass a HPT with no bubbles after going through your settling process with no external drying at all?

From the time you collect your oil and bring it home, exactly how long would it be sitting in the cubees or upflow barrel and would you normally have it long enough to go through one or more freeze/ thaw cycles?

quote:

no bubbles after going through your settling process with no external drying at all?

correct, VO through the last filter is dry

Do you pass the oil through the Quick and dry or anything similar at any stage of your process before it exits the last filter?

Q&D is used as a drying indicator at the intermediate filter stage. After processing hundreds of gallons of VO and BD the Q&D shows only minor expansion.

My experience with used canola oil shows that when the VO freezes then thaws the clear layer of VO gets drier, the creamy layer of PHO and fats might dry some but still stays wet and so does the bottom sludge layer. PHO and fats have a great affinity for moisture and the dissolved/suspended water that they hold may not settle out. Aggressive heating methods may be required to thoroughly dry PHO and fats. I find it's easier to avoid using PHO and fats for vehicle fuel and instead use them for heating fuel where the moisture isn't a problem.