Is anyone running a heated tank with blends? Just wonderng because I am considering this as an option wanted someone with experiences input.

If you are planning to heat this tank to a high temperature, then blending with solvents may be dangerous and polluting.

That's because the high heat may boil off the solvent into an explosive cloud. Even without a spark, the solvent vapour cloud poses health risks and is a form of pollution.

Aside from those two risks, there's the issue of cold starting your engine on the last 1/3 of a tank of blended fuel that no longer has the solvent required to help cold start combustion efficiency.

Remember that unless you loop your IP/injector return lines, the hot return fuel will add more heat to the already heated tank, potentially overheating the fuel and boiling off the solvent.

All this having been said, I do believe that many folks have successfully run heated blends, but I think they heat their tanks to a mild to moderate temp, not like a Greasecar SVO coolant heated tank.

Heres a forum search on "heated blends":


http://biodiesel.infopop.cc/eve/forums?a=search&reqWord...Type=1&search=Search

Here's a search on posts by John Galt with blends/blending as added search terms:


http://biodiesel.infopop.cc/eve/forums?a=search&reqWord...Type=1&search=Search

John runs blends. Tim Cook blends almost anything flammable (hard to kill a Cummins!). I think DCS runs blends too.

quote:

Originally posted by miller0613:
Is anyone running a heated tank with blends? Just wonderng because I am considering this as an option wanted someone with experiences input.

What kinds of blends and what kind of tank heater?

I wouldn't heat the entire tank much above 80F for VO. Blends are a somewhat different beast.

Consider the physical characteristics of your blend liquids. Note, that the relative blended physical characteristics will not be a linear approximation according to the blend constituents. Whether you are blending for viscosity, lubricity, density, conflagration, atomization, emissions, power, efficiency, or augmenting cold starts, especially if you are blending to avoid vapor lock, it is something to be aware of so you can accurately predict your results. i.e., mixing 50% ULSD with 50% refined rapeseed oil won't make for a viscosity which is half that between VO and ULSD. There is, thankfully a formulae for determining the viscosity of liquid blends:

http://en.wikipedia.org/wiki/Viscosity#Viscosity_of_blends_of_liquids

Or, e.g., when you mix alcohol (low boiler) with water (mid boiler), depending on the concentration of the mixture, there will be a non-linear relationship between mixture strength and boiling point, in this case, a positive binary azeotrope of the miscible liquids is formed and the boiling point of the mixture is actually lower than either liquids individually.

From: http://en.wikipedia.org/wiki/Azeotrope
"A well known example of a positive azeotrope is 95.6% ethanol and 4.4% water (by weight). Ethanol boils at 78.4°C, water boils at 100°C, but the azeotrope boils at 78.1°C, which is lower than either of its constituents. Indeed 78.1°C is the minimum temperature at which any ethanol/water solution can boil."

You might also want to take a look at the National Technical Information Service's archives, e.g.

http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPre...identifier=ADA031902

and these guys are super smart:

http://www.ogj.com/articles/save_screen.cfm?ARTICLE_ID=338884
"Study predicts viscosity of gas oils, heavy blends"

While they are researching petroleum hydrocarbons, VO is a hydrocarbon and they are both technically "organic" I like to keep up on the scientific literature because it gives a great context for the variables to consider when blending fuels.

You might also want to check out:
http://www.springerlink.com/content/e382123u8371j3p5/
"Received: 24 January 2002
Accepted: 20 July 2002
Abstract: Blending is often used to reduce the viscosity of vegetable oil lubricants. Experimental rheological results were compared with traditional blending charts and calculation methods. Kinematic viscosities of 90% oleic sunflower, canola, and soybean oils blended with adipates, oleates, polyalphaolefins, and mineral oil were determined at 40°C using capillary viscometers. Blending charts related the viscosities to blend composition with 5% inaccuracy compared with more than 10% deviation made by the cubic equation of Kendall and Monroe. Even more accurate and simpler correlations could be derived. A semilog relationship between viscosities and composition was more accurate than a cubic model. Higher accuracy was also achieved when relating viscosities to volume fractions rather than to weight or mole fractions. Mineral oil blends did not follow the observed rules."

Aloha!