Sweet & Sour, Heavy & Light

One has heard of tea-tasters but it is hard to believe that at one time, there were also professional crude-oil tasters.

In the 19th century workers in the fledgeling oil industry used their sense of taste and smell to classify petroleum into four categories - sweet, sour, heavy and light. These days the same classification is used to determine the cost of the petrol or diesel that goes into our motor vehicles.

Any crude with more than 2.5% sulphur is called sour. Most of it comes from the Middle East. Sweet crude, on the other hand, is what is exported out of Africa, Europe (North Seas) and also supplied by the oil wells in India. Light crudes yield the more valuable gasoline, naphtha and kerosene while heavy ones give more diesel, fuel oil and residue. So in the crude-oil business, sweet & light is anyday better than heavy & sour.

One point, however, remains unclear: Is there any such thing as heavy & sweet oil?

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REFERENCES & LINKS


* Choudhury, Ranabir Ray (2006): The balancing act with trade parity oil prices, BL 09Jan06, URL - http://www.thehindubusinessline.in/2006/06/09/stories/2006060903550300.htm

* Types of Crude Oil - http://nesteoil.com/default.asp?path=1,41,538,2035,5196,5197,5199

* Description of the MC 252 Crude Oil - http://oilspill.fsu.edu/images/pdfs/mc-252crude-oil-desc.pdf

* Ranjan, Amitav (2012): HOW PRICES ARE FIXED, BARREL BY BARREL, IE 07Jun12, URL - http://www.indianexpress.com/news/how-prices-are-fixed-barrel-by-barrel/958747/
- Sweet vs. Sour - any crude with more than 2.5% sulphur is sour
- Heavy vs. Light - Light crudes yield more gasoline, naphtha and kerosene while heavy ones give more diesel, fuel oil and residue.
- Though indigenous crudes from Assam and Mumbai High are sweet, they accounts for only 17 per cent of the total processed.
- Indian imports comprise nearly 80 per cent of sour crudes of which 82 per cent are from the Middle East. Of the 20 per cent imports that are sweet, Africa sends 99 per cent.