Story last updated at 7:16 PM on Wednesday, December 3, 2008

Black gunk that fouled heaters, frustrated repairmen identified


Last winter, a mysterious black gunk that clogged up the fuel screens of oil heaters baffled repairmen and fuel companies. After Petro Marine started distributing ultra-low sulfur fuel in early 2008, repairmen saw service calls go from a half-dozen to hundreds.

"I've been basically on the front lines of this," said John Ferrell, "The Toyo Man," who repairs Toyo brand heaters, last winter.

Mark Vial of VBS Heating Products also said he had 20 times the number of calls for clogged screens last winter.

Heaters using Jet-A diesel fuel didn't have the problem with fuel-screen clogging.

Repairmen figured out the problem came from a strange substance clogging the fuel screens of Toyo and Monitor heaters using ultra-low sulfur fuel, but were clueless as to where the gunk came from.

Not anymore. Petrochemical scientists from Tesoro, the supplier of ultra-low sulfur fuel to Petro, analyzed the substance. The problem? An amide-based lubricity additive put in ultra-low sulfur fuel. Amides are organic compounds containing nitrogen.

"It took a long time to figure out. Once we found the guck that was the problem, we sent it up to Tesoro to look at in their labs," said Smokey Norton, director of marketing for Petro in Anchorage. "Little did we know the goop we were mixing in there for lubricity -- that was the problem," he added.

Ultra-low sulfur diesel is a fuel product that has had sulfur removed, reducing the content from 3,000 parts-per-million to 15 ppm. The U.S. Environmental Protection Agency mandated ultra-low sulfur fuel be sold for most diesel engine vehicles starting in 2006. The ultra-low sulfur fuel made by Tesoro was on spec and met testing standards for vehicle fuel. Because sulfur adds lubricity to fuel, by removing the sulfur chemists have to add another lubricant to make up for the lost sulfur.

Amide-based lubricants in ultra-low sulfur fuel had caused similar heater problems in western Canada.

"Had this information been better distributed from years gone by when ultra-low came into the marketplace in western Canada, lubricity wouldn't have been a problem," Norton said.

Ester-based lubricants don't clog up fuel screens. Esters are organic compounds formed by the reaction of an acid and alcohol with the elimination of water.

When customers and repairmen complained about ultra-low sulfur fuel last winter, Petro responded by pumping out fuel tanks with ultra-low sulfur and replacing it with Jet A. Petro sells Jet A for home heaters and no longer sells the ultra-low sulfur for heating fuel. Petro also advised customers with repair bills related to the ultra-low sulfur fuel to file claims.

"Anybody who called us with an kind of problem, we told them to make a claim, and we'll treat it like a claim -- and we did," Norton said. "We settled a god-awful amount of claims," he added.

Norton said he thinks most of the customers with ultra-low sulfur fuel have had it pumped out. If people still have ultra-low sulfur fuel that Petro delivered last winter, Petro will pump it out and replace with Jet A.

"My guess is most of the problems have been resolved," Norton said. "We got very aggressive in taking the claims."

Michael Armstrong can be reached at