Biodiesel Congeals, School Buses Stall

[Baack]

Last month I wrote an article about the difficulties that winter conditions pose for various forms of renewable energy.
Biodiesel congeals at low temperatures, as John Jones, the transit director for the Summit Stage bus service in the Colorado mountains told me. He stopped using biodiesel in the winter after one of his buses filled with drunken revelers — and fueled by a biodiesel blend — stalled on the interstate in the middle of a frigid winter night.
Now a similar problem has hit Minnesota school buses, which also run on a biodiesel blend.
According to The Minneapolis Star Tribune, some school buses stalled in last week’s bitterly cold weather. Children got stuck in stalled buses or had a long wait in the freezing weather at their bus stops.

http://greeninc.blogs.nytimes.com/20...l-buses-stall/

[Roadmedic]

The head of our truck maintenance department was blaming the drivers for not adding anti gel during last week's cold spell. He said they were the reason the APU's and trucks were not running.

He stated the same thing to me and I said to review the records and he would find I was using their anti gel and if it was the reason the APU quit why was the truck engine working.

I told him Pilot in Illinois is bio diesel. I told him how it gels at a much higher temperature and is unreliable in the winter. He still disagrees with me. I will not use bio in the winter in my personal diesel. I didn't use an additive and it started and ran fine.

[25(2)+2]

Gelling isn't as much problem with large engines that use a pressurized rail with a cam actuating each injector, the engines bypass hot fuel back to the tank(s) in large amounts, when they are running, they shouldn't gel. There are some exceptions to this where engines are modified to return less to the tank, some Volvo engines were set up like that for sure

The smaller engines that were the norm for buses and lighter vehicles are very prone to gelling in the lines and tanks since there is only a little fuel bled back to the tank because those engines used a high pressure injection pump tp time the injection and those lines are exposed to outside temperatures and often have a cold blast from an engine driven fan that is not clutched blowing around those lines. Gelling was a problem with farm tractors back in the day but I can't remeber any of mine gelling up, I was careful.

I have used bio in the winter but our trucks are run until the temps get back into the 20s at night, which will be awhile. Minnesota has a B2 mandate, all diesel has to be at least 2% bio unless it's been rescinded for some reason, most pumps in MN are not marked unless they are higher in bio than the 2 %

We had temps approaching and exceeding minus 30 last week, most schools delayed and canceled rather than risk buses gelling in those conditions. Too bad the people running the schools in MN don't listen better to people that actually understand running diesel engines in cold weather. They could add NO.1 or antigel to the tanks and not have the problem, at minus 20 or lower, the engines run better on lighter fuel.

The APUs don't bypass much back either and the draw is so low that the fuel can gell in the lines. Use plenty of antigel if you aren't running the main engine.

Some antogell directions call for doubling the amount used if you are using bio diesel.

[Sad_Panda]

Also be careful of the blend, I had a batch made with animal fat and it gelled at like 50F

[tdb]

Ha ha, oops! Check out the editorial correction that's been added to the article:

UPDATE 1/23 12:10pm: The [LINK POSTED BY MEMBER] Only Members Can View This Truck Forum Link. emailed me to draw attention to a [LINK POSTED BY MEMBER] Only Members Can View This Truck Forum Link. released today that says that diesel, rather than biodiesel, what what stalled the school buses. The study was paid for by Yokum Oil, the fuel distributor. “We found that whatever was plugging the filters was not biodiesel, but a substance found in petroleum,” the brief report states.