A fire, which broke out at the ConocoPhillips refinery on Christmas Eve, has been identified as a heater inside the tank, which set fire to the oil vapours.
It was found that the blaze broke out after oil was being removed from a tank. The oil level fell below a heater inside the tank and resulted in the vapours catching fire.
Clint Young, a spokesman for the refinery, said, We are implementing operational changes to prevent fires from occurring when we remove products from tanks in future.
The fire, which began around 3.20pm, burned for two and a half hours before the Billings Fire Department, and fire crews from the CHS refinery in Laurel and ExxonMobil refinery in Lockwood managed to put it out. However, a tank in which the blaze was contained was ruined.
ConocoPhillips reported that during the fire 6.8 tonnes of sulphur dioxide, 10.4 tonnes of particulate matter, 5 tonnes of carbon monoxide, 1.5 tonnes of hydrocarbons and 400 pounds of nitrogen oxides were emitted. No one was injured.