Cold temperature Biodiesel question - Ford Truck Enthusiasts Forums

Go Back   Ford Truck Enthusiasts Forums > Diesel > Bio-diesel, Propane & Alternative Diesel Engine Fuels
Log In 

Cold temperature Biodiesel question

LinkBack Thread Tools Search this Thread
Old 12-04-2006, 04:52 PM
rickgthf rickgthf is offline
Junior User
Join Date: May 2006
Posts: 69
rickgthf is starting off with a positive reputation.
Cold temperature Biodiesel question

Can someone explain to me how blending biodiesel with regular diesel work to prevent gelling at cold temperatures? I ask this question in view of my current observations of samples of biodiesel and biodiesel blends setting on my porch rail the last few weeks as the temperature fluctuates between 50 F and 20 F.
I have four samples of biodiesel (that I made with different lots of used cooking oil) and one sample of 50/50 blend. At 50 F (even down to 30 F) the straight biodiesel samples are all clear except for a thin layer of fine white precipitation that resulted after the first hard freeze (28F). As the temperature drops below 30 F a white flocculant forms in each of the four BD samples although all have different amounts at different temperatures. For example this morning at 24 F one sample was completely "gelled", a second was completely gelled except you could see small areas of liquid, the third was three quarters gelled and the fourth only about one quarter gelled.
Previously I observed the same results but noted that as the weather warmed all the samples would re-liquify to a clear state.
Now the 50/50 blend will be clear until the temperature drops but a generalized cloudyness will begin to form at the temperature declines. As the temperature continues to decline not only will the fuel cloud but increasing amounts of white flocculant forms at the bottom.
I suspect that even with substantial regular diesel blends (B20) some flocculant will form since the various methyl esters (palmate, oleic, stearate, etc.) will gell at different temperatures irrespective of how low their respective concentrations.
This being the case what does it matter the blend because eventually the filter will plug unless the fuel is warmed somehow. Any comments?
Reply With Quote
Old 12-04-2006, 06:04 PM
Phydeaux88's Avatar
Phydeaux88 Phydeaux88 is offline
Posting Guru
Join Date: Dec 2003
Location: South Texas Coast
Posts: 1,570
Phydeaux88 is gaining momentum as a positive member of FTE.Phydeaux88 is gaining momentum as a positive member of FTE.
In BD Petro blends the BD is diluted. In doing so space between BD molecules is increased enough that they have difficulty forming the crystals you refer to as a white flocculant.

Gell point in BD depends on the feed stock used because they all produce different ester mixes and some mixes will gell more easily. I would bet it has to do with the length of the second hydrocarbon chain.
2006 F350 4X4 Crew Cab King Ranch edition strictly factory, for now.
Reply With Quote
Old 01-02-2007, 02:08 PM
dslmn dslmn is offline
Freshman User
Join Date: Oct 2005
Posts: 33
dslmn is starting off with a positive reputation.
The white flecks you see are more probably waxes and other long chain carbon molecules. Your filter should catch them, and they will redissolve and feed on through when the filter warms up. The real danger is plugging the filter in prolonged cold temps and temporarily shutting down fuel flow. But, if your filter sits on top of the engine as in the 7.3 it will be warmed by engine heat and should be OK once the engine warms up. The inline filter found on the 2004 6.0 pump, mounted inside the frame rail is going to be much more likely to plug up in cold conditions and will not be warmed up.
Reply With Quote
Old 01-02-2007, 02:08 PM

Go Back   Ford Truck Enthusiasts Forums > Diesel > Bio-diesel, Propane & Alternative Diesel Engine Fuels

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are On
Pingbacks are On
Refbacks are On

Forum Jump

All times are GMT -5. The time now is 02:29 PM.


Powered by vBulletin® Version 3.8.7 AC2
Copyright ©2000 - 2015, Jelsoft Enterprises Ltd.
Advertising - Terms of Use - Privacy Statement - Terms of Service - Jobs
This forum is owned and operated by Internet Brands, Inc., a Delaware corporation. It is not authorized or endorsed by the Ford Motor Company and is not affiliated with the Ford Motor Company or its related companies in any way. FordŽ is a registered trademark of the Ford Motor Company.

vbulletin Admin Backup