Q & A > Question Details
Is there an an agreed percentage of sulphur that determines whether a crude is classed as low or high sulphur?
27/10/2009 A: Fawzi Elfghi, University of Nizwa, felfghi@gmail.com
Generally, the sulfur content of crude oil and its products varies from less than 0.05 wt.% to more than 14 wt.% but regularly arise in the range of 1 to 4 wt.%. Hydrocarbons which contain less than 1 wt. % sulfur content are attributed to as low-sulfur crude oils and those above 1 wt. % as high-sulfur petroleum.
31/08/2009 A: Lindsay McRae, Pall Corporation, Lindsay_McRae@pall.com
<1% is generally considered to be low Sulphur. 3% or greater is considered to be high sulphur. Kuwait crudes considered high sulphur as has ~ 4% Sulphur. Arah Heavy (AH) is generally having 3+% Sulphur. However Sulphur is not the only contaminant measured in crude that infludences the price. Contaminanats like Hg, Ar, V, and N also effect crude prices.
19/08/2009 A: Alan Goelzer, Jacobs Consultancy, alan.goelzer@jacobs.com
Whole crudes like West Texas Intermediate Crude and North Sea Brent Crude with less than 0.5 wt% organic sulphur contents are obviously considered "low sulphur" or "sweet".
Whole crudes like Arabian Light Export Crude with 1.8 wt% organic sulphur are obviously considered "high sulphur" or "sour".
Bitumens [API Gravity = 7 to 10] and Extra Heavy Crude Oils [API = 11 to 15] are typically very high in organic sulphur and thus "sour".
For whole crude oils with organic sulphur contents between 0.6 wt% to 1.7 wt%; there can be some debate about whether these should be classified as "high sulphur" or "low sulphur". Certain petroleum refineries may be able to deal with organic sulphur levels in distilled straight-run fractions on the higher end of this range, while other petroleum refineries may become challenged at the lower end of this range.
Cautionary Note = The petroleum refining industry and crude traders use the terms "sweet" and "sour" to define relative contents of organic sulphur in hydrocarbon-like organic sulphur species. However, upstream oil and gas production industry use the term "sweet" to mean very low levels of H2S in either produced gas or associated gas or dissolved in raw crude in the separators, while "sour" means elevated to very elevated levels of H2S. The underlying crudes may be either "low sulphur" or "medium sulphur" or "high sulphur".