Britannica Sources used in this answer

How hot is crude oil heated before entering a refinery fractionating column?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Aerial view of an oil refinery complex near New Orleans, Louisiana, with storage tanks, industrial structures, and smoke rising from the facility, surrounded by open land. — petroleum refining Aerial view of an oil refinery near New Orleans.

In a modern crude oil distillation unit, the desalted crude oil is heated in a furnace before entering the fractionating column. The oil is typically heated to a temperature between 315 and 400 °C (600 and 750 °F), with the specific temperature depending on the type of crude oil being processed and the desired end products.1

This heating process occurs after the oil has been preheated through a series of heat exchangers and passed through a desalting drum to remove impurities that could otherwise cause plugging in the furnace tubes. Once the oil reaches the required temperature, a mixture of vapor and unvaporized oil is directed into the fractionating column for separation.1

In contrast, when refineries use vacuum distillation to process heavier materials, the furnace conditions are adjusted so that oil temperatures generally do not exceed 425 °C (800 °F) to avoid thermal cracking.2