ULSD clogging filters at 0-10 degrees

[moeh1]

The local buses weren't running this week until they mixed ULSD Kero in with the diesel. See Cold Freezes Bus Fuel—Closes Schools - 13WHAM.com

 

[Bob_Young]

The question is:

If they can't do the science in advance to determine the problems ULSD might cause and how to avert them; then how do we know they did the science to prove ULSD was needed to begin with?

Is this all just political?
Bob

P.S. Pleeeze, don't justify it with what Heidi Cullen says

 

[MadReferee]

If they can't do the science in advance to determine the problems ULSD might cause and how to avert them; then how do we know they did the science to prove ULSD was needed to begin with?

Their problem most likely has nothing to do with the science to prove anything about ULSD. Old LSD diesel would have done the same thing.

I'll wager the ULSD that the bus company is using is summer blend. They probably bought a significant quantity in the thousands of gallons in the summer to beat the winter price increases. Serves them right for not properly maintaining their fuel with some additives like Power Service. Anything to save a buck.

 

[SkyPup]

LOL

Serves 'em right, too bad they don't have something better they could try to blame their problems on.....at least the kids got a day off from school due to their poor planning.

 

[themichelob]

I can't see how this has anything at all to do with ULSD. All diesel fuel will gel at low temperatures if not winterized, regardless of the sulpher content. Let's not try to make it political...

 

[DieselPower]

Actually the gel point of ULSD is higher than LSD. I have seen a couple of lab reports that showed the average gel point of untreated fuel was 7 degree's F.

The real problem is that this was known a long time ago. Every diesel technology magazine, school bus contractors magazine, trucking magazine and power generation magazine I get has had articles in them for month's about ULSD and most all of them noted the higher gel point. They can't say the information wasn't out there.

It is a shame that they had these problems but if they had properly planned in advance they would have been adding pour depressants to their fuel before the problems occured. Poor planning leads to problems just like this.

 

[SkyPup]

The ULSD gel point is slightly higher because it contains allot more paraffins and allot less aromatics, in other words, it is much more like diesel fuel was prior to the Arab Oil Embargo back in the '70's when refiners resorted to more cracking.

 

[Bob_Young]

Are you sure this is all about planning? This week's temperatures haven't been at all uncommon for this area this time of year. Managers of diesel fleets have to be prepared for temperatures as low as -20 F. as it can and has happened. A bus full of children stuck on a country road in a dead bus in NY snowbelt weather is a nightmare scenario. You better believe they've heard of fuel gelling and are concerned about it.

Multiply that by 20 or so busses in each of 17 plus school districts and people from Florida "LOL". I'll remember that come hurricane season.

Usually each school district here operates its own fleet of buses. Historically they've done very well in operating reliably and without incident. I might believe there might be a transportation manager in one or two districts that weren't prepared for ULSD gelling characteristics; but 17 districts? C'mon!

Could be there's something more to this. We're not all stupid up here.
Bob

 

[DieselPower]

Their problem most likely has nothing to do with the science to prove anything about ULSD. Old LSD diesel would have done the same thing.

I'll wager the ULSD that the bus company is using is summer blend. They probably bought a significant quantity in the thousands of gallons in the summer to beat the winter price increases. Serves them right for not properly maintaining their fuel with some additives like Power Service. Anything to save a buck.

I seriously doubt they are still using old summer blend (unless they have a very poor fuel supplier, who knows). A very close friend of mine has a fleet of 33 school bus's and he goes through about 4,000 gallons of fuel per week. Fuel goes fast in a bus. Bus's are on the road a good part of the day and use quite a bit of fuel. His fleet averages about 6.5 MPG.

As for the LSD gelling also, I would also doubt that. The new ULSD has a much higher gel point compared to LSD. Here's a lab report that shows untreated it gel's at +7 degrees F. Could LSD have gelled, sure, but not as easilly as ULSD.

Bob_Young - I'll find out more tomorrow about their problems. I called the superintendant of schools (Dr. Graham) today and he is going to give me a call back tomorrow to talk about their problems and see if there is anything I can do to help. I'll keep you updated what their reply is.

 

[Iowachild]

ULSD is coming right off the treating unit at our refinery with a cloud of -16 degrees F and a pour point of -34 degrees. The "all weather diesel", treated with among other things a pour point improver, had a pour point of -44 degrees F yesterday. BTW we have a terminal in Rochester, NY.