Sour crude oil
Sour crude oil is crude oil containing the impurity sulfur. It is common to find crude oil containing some impurities. When the total sulfur level in the oil is > 0.5 % the oil is called "sour".[1]
The impurities need to be removed before this lower quality crude can be refined into petrol, thereby increasing the cost of processing. This results in a higher-priced gasoline than that made from sweet crude oil.[1] Thus sour crude is usually processed into heavy oil such as diesel and fuel oil rather than gasoline to reduce processing cost.
The majority of the sulfur in crude oil occurs bonded to carbon atoms, with a small amount occurring as elemental sulfur in solution and as hydrogen sulfide gas. Sour oil can be toxic and corrosive, especially when the oil contains high levels of hydrogen sulfide.[2] At low concentrations the oil has the smell of rotten eggs, but at high concentrations the inhalation of hydrogen sulfide is instantly fatal.[3] At higher concentrations, the hydrogen sulfide can damage the olfactory nerve, rendering the gas effectively odorless and undetectable, while paralyzing the respiratory system.[4] If exposure is not fatal, its effects on the human body are similar to that of Gulf War Syndrome including chronic fatigue, headaches, dizziness, skin problems, memory problems, birth defects, and a host of breathing problems such as asthma. Sour crude oil needs to be stabilized by having hydrogen sulfide gas (H2S) removed from it before being transported by oil tankers for safety reasons.[5]
Since sour crude is more common than sweet crude in the U.S. Gulf of Mexico, Platts has come out in March 2009 with a new sour crude benchmark (crude oil) oil marker called "Americas Crude Marker (ACM)".[6] Dubai Crude (and Oman Crude) both sour crude oils have been used as a benchmark (crude oil) oil marker for Middle East crude oils for some time.
Major producers of sour crude oil:
North America: Alberta (Canada), U.S. Gulf of Mexico and Mexico. South America: Venezuela, Colombia and Ecuador. Middle East: Saudi Arabia, Iraq, Kuwait, Iran, Syria and Egypt.[1]
See also
References
- ↑ 1.0 1.1 1.2 "Heavy Sour Crude Oil, A Challenge For Refiners". http://www.commodity-trading-today.com/sour-crude-oil.html.
- ↑ "Petroleum Introduction". http://72.14.207.104/search?q=cache:S9rTxAtEiM4J:www.leeric.lsu.edu/bgbb/3/display.html+&hl=en&ct=clnk&cd=1&client=firefox-a. Retrieved 2006-05-08.
- ↑ "Schlumberger Oilfield Glossary". http://www.glossary.oilfield.slb.com/Display.cfm?Term=hydrogen%20sulfide. Retrieved 2006-05-08.
- ↑ "Hydrogen Sulfide & Sour Crude". http://www.michigan.gov/documents/cis_wsh_cet5041_90142_7.doc.
- ↑ "Sweetening Up the Crude". http://www.saudiaramcoworld.com/issue/196001/sweetening.up.the.crude.htm.
- ↑ Americas Crude Marker (ACM)
