Blending of WVO / VO

[veggie]

Hi guys,

There seems to be a lot of interest in this topic so I thought I'd kick off a thread on WVO blending.
For many, this is a much simpler alternative to pre-heating straight WVO / VO.

I've done a LOT of research on this subject (the last thing I want to do is screw up my beloved Changfa...or my new 6/1).
Fuel blending has been done in the UK for many years and until the government outlawed the blending of kerosene it was common to use it in VO. There are some users with a considerable number of miles on there vehicles using WVO blends. One key difference is that many of the engines reported are multi-speed vehicle engines rather than fixed speed stationary units. Blenders in the UK have now switched to regular unleaded gasoline (RUG).
Many stationary test reports were conducted with SVO and the results vary all over the map. WVO blending tests are not easy to find.

I have studied many blends and mixtures, but there is a common thread of successful stories based on the following formula.
Let's break down the requirements....

Four requirements (of any blend formula) come to mind:

1] To get close to the viscosity of regular diesel without using heat.
2] Maintain adequate lubrication of the fuel system.
3] Maintain complete combustion.
4] Maintain a stable, non-separating mixture

To satisfy #1 we can add Kerosene or RUG as a diluent. This is not intended as a fuel. Its a viscosity reducer and the general consensus is that this component should not exceed 40% of the total mixture, with 15% being most common. The more you use, the lower the cetane rating of the overall batch.

To satisfy #2 we add a diesel fuel lubrication additive (which is now also recommended for dino-diesel due to ultra low sulfur fuels). This is precautionary.

To satisfy #3 we can choose a fuel lube additive that also has cetane boosters. As an example, "Super Diesel Plus" from Lubecorp. has cetain boosters and a lube component.

#4 WVO can have dissolved fats that do not get caught by filters and can emulsify or coagulate due to cooler temperatures or standing time. To satisfy this, one can add 1% turpentine which tends to do a very good job of reducing fats, preventing coagulation, and adds some stability without effecting combustion.

Another point worth mentioning is engine temperature and loads. Full operating temp and loads of 80% or better should increase the chances of maintaining complete combustion.

Again, there does not seem to be any documented lab tests on mixtures such as this.
If anyone is running blended WVO/VO fuels on a continuous basis, please share any blending suggestions or anecdotes with the rest of us.

Cheers,
Veggie

[mobile_bob]

i have a little aircooled changfa 4hp diesel, i think it is the r170? not sure

i am considering setting it up on a wooden slab and mount an alternator on it
with one of those doc watsons to track kwatt/hrs dc
and i have some nice load bank wire wound resistors that can take all the amps the little engine
can deliver...

maybe it would make a good fuels test engine, i think i would rather risk damaging it working with
alternate fuels as damage the 195.

being aircooled the cooling system variable would be eliminated, then all i would need would be
a pyrometer probe for my pryo, and maybe a head temp gauge i think i saw suplus center has them.

i could then run a battery of tests at various fixed loads repetitively so i could get consistent results
the cylinder head is easy enough to remove and maybe one could use a razor blade to scrape off the
residue from the piston top and weigh it to determine how clean various blends burn relative to each other.

may not be exceptionally accurate, but ought to sure illustrate a really bad fuel as opposed to one that
looks adequate?

for example,

fuel A, starts adequately and produces 1kw/hr burning X grams of fuel and when i have tested for Y hours
and removed the head, scraped the head, weighed the carbon and found it to be Z grams


fuel B, starts adequately and produces 1kw/hr burning .95X of fuel (which on the surface looks like a better fuel)
ane when tested for Y hours and the head removed, piston scraped, weighed and found to be 1.5Z  then

even though fuel A, looks to be a much more powerful fuel, i might not want to use it because it produces 50% more
carbon on the piston which would require much higher frequency of maintenance.

and if either fuel produced a gummy deposit, well we know we don't want that under any circumstances
to get anal about testing fuels is going to require an extensive a varied battery of tests, not only all the various fuel blends/viscosity/
cetane rating, etc. but also stepped changes in comp ratio, injection timing and maybe even alteration of injection pressures.

would be very interesting to do, not sure how useful it would be unless one had a consistant and long term source of a fuel stock
so you could do all the testing to optimize it for a specfic engine, further optimize the engine to use the fuel, with some assurance
that you wouldn't have to redo all the testing with each batch coming in from whereever you get the fuel stock.

veggie oil is a tough stock in that regard, it varies from species to species, variety to variety, climate to climate, field to field making
it somewhat a challenge to get it near perfect, and if it is waste comeing from restaraunts?  who knows?

luckily these diesel engine's aren't too picky what they are fed, they will run on just about anything flammable

bob g

[veggie]

Bob,

I think that's an excellent idea!
Finally we would have some documented results. All-be-it relatively short duration runs.
I agree with your comment about WVO quality consistency.

Perhaps for the small amounts of fuel you are burning, you could buy processed canola oil right off the shelf.
(Unless you have a reliable way of pre-processing some WVO to get a consistent supply.)
At least this would give 100% consistency in the base stock.

Then test SVO vs Blended VO vs DinoDiesel.
Although it would be useful if you could get some dewatered/filtered WVO for the test.

Besides, that little r170 Changfa being ignored over in the corner of your shop is just dying to do some work and produce something useful. Are you ignoring it ?....Don't make me report you to the SCE. (Society for Cruelty to Engines).

Cheers,
Veggie

[LowGear]

Hi Veggie,

Have you heard anything, up or down, about the AMSOIL diesel additive product?  I tried google but it's just turned into an advertising forum.

Casey

[veggie]

Hi LowGear,

No, I have not heard of this product.
It would be interesting to know if it's a fuel lubricant (for ultra low sulfur diesel) or a combustion enhancer. (or both ?).
The main reason for additives in WVO blending is to increase the cetane rating.
If the additive does not do that, then it may be of little use.
Let us know if you come up with anything.

Cheers,
veggie

[veggie]

LowGear,

Amsoil has a few different additives for diesel.
You can see them here....
As I suspected, two of them have lubrication and anti-gel properties for low sulfur diesel.
http://www.oilsandlube.com/diesel_fuel_additives.htm

The only one I would recommend using as a blending component with WVO  is the "Cetane Boost Additive"
All the others are formulated to enhance/react with dino-diesel and not vegetable oil.

Cheers,
Veggie

[cognos]

Here is a link to a manufacturer's site - Fuel Magic. These guys make a cetane improver.

http://www.fuelmagic.net/Cetane%20Booster.html

Now - this isn't an endorsement, I have no affiliation with this company, I've never seen the product, used the product, have no idea if it's any good at all...

So why provide the link, you ask?

If you just skip the product advertising, lower down on the page is some of the best explanations of the properties of diesel and what a cetane improver does. Certainly better than I could have written. I suppose I could have cut 'n pasted it, but you people might as well see it in context, and make up your own minds.

It correctly identifies alkyl nitrates as what most commercial diesel cetane improvers consist of - and why one should be careful using them, due to their ability to cause oxidation if you store treated fuel.

(They say theirs doesn't contain any, so it could very well be snake oil, for all I know... )

[LowGear]

The bad news is that I don't have the cetane improver product.  The good news is that I only have three bottles left and, and I run B20 purchased at my local coop.  It has half the nasty smelling and tasting crap that B0 has.  It doesn't cause my voice to go away after an hour on the tractor either.

But when I get the bio-factory pooping out the magic stuff I'll be using Super Diesel Plus, Fuel Magic or a very close cousin.  I plan to cut the prime stuff with about 1/3 very clean vegetable oil and a snort or two of RUG for every 5 gallon can of product.

What a neat website this and the other one are for information without worrying whether the 20% commission has confused the advisor.

Casey

[cognos]

Wow, the deeper I got into that Fuel Magic site, the more skeptical I got... I'd just stick to of the third-party explanations, and skip the claims...

I have no doubt that after-market lubrication/cetane improvers do exactly as they say. Since the technology is fairly straight-forward, skip the snake oil and buy the least expensive...

[veggie]

LowGear,

You mentioned that you are using biodiesel in some cases.
I'm not sure if you are aware, but biodiesel actually has a higher cetane rating than dino diesel.
Cetane boosters are only necessary if you are blending WVO or SVO.
Some people don't add any cetane booster at all.
IMHO, it helps maintain complete combustion and reduce coking.

Veggie

[LowGear]

Hi Jens,

Now there's a test outcome that should be worth reading.  I hope I don't miss it.

Casey

[cognos]

I take it the fouling is on the exhaust side of the exchanger.

In exchanger design, the dirtiest product is always on the "tube" side of a shell and tube exchanger.

How about a water mist injector in the exhaust just prior to the exchanger? Turn it on every now and then, might cut down on the need for disassembly to clean?

What is the primary foulant? Soot accumulation? Hard carbon? Matrixes - carbon + "gums"/unburnt fuel?

 

[veggie]

I am using straight WVO without any additives and this year I am running one cylinder with a heated high pressure line and one without. I will compare the two heads when the heating season is over.

..... and I have to clean the damn exhaust heat exchanger again. I wonder if additives would improve that situation. I always look like a chimney sweep after the cleaning

Jens

Hi Jens,
Adding the cetane booster is quite popular with the automotive diesel blenders for raising the cetane rating after diluting the WVO with regular unleaded gasoline (RUG). As you may know, the RUG reduces the overall cetane rating of the blend and the cetane booster helps overcome this reduction.
The cetane booster also acts as a combustion catalyst, and for that reason, it may help WVO combustion also.
There is little or no published tests to verify this, just anecdotal evidence from many automobile diesel blenders.
I don't see a downside to adding the cetane booster to your WVO (in the mfr's specified quantities).

Veggie

[vdubnut62]

Jens, what would happen if you plumbed line pressure water, at least a 1/2" line into the exhaust between the engine and the heat exchanger.
Run the engine at full load and throttle and flush the exchanger with water for five or ten minutes or so, then turn off the water and let it dry from engine exhaust? Probably cut 'way down on the loose flyaway stuff.  You may not be able to try my hare-brained scheme due to the way your exhaust is  made or maybe you could catch the water/crud in a 55 gallon drum? Quite possibly I'm just delusional
Ron

[cognos]

That's actually what I meant to imply - a water injection line just before the exchanger. Hot engine, full throttle, etc.

One could add some regular dishwashing detergent to the initial injection water for a more effective flush, then just follow with clean water.