Petroleum deasphaltening

Deasphaltened oil the fraction of petroleum after the asphaltenes have been removed. 

Deasphaltening removal of a solid powdery asphaltene fraction from petroleum by the addition of low-boiling liqnid hydrocarbons snch as n-pentane or n-heptane nnder ambient conditions. 

Maltenes that fraction of petroleum that is soluble in, for example, pentane or heptane deasphaltened oil q.v.y, also the term arbitrarily assigned to the pentane-soluble portion of petroleum that is relatively high boiling (>300°C, 760 mm) see also Petrolenes. 

Deasphaltened oil the fraction of petroleum after the asphaltenes have been removed using liquid hydrocarbons such as n-pentane and n-heptane. 

Finally, during the fractionation of petroleum, the metallic constituents (metalloporphyrins and nonporphyrin metal chelates) are concentrated in the asphaltene fraction. The deasphaltened oils (petrolenes and maltenes) contain smaller concentrations of porphyrins than the parent materials and usually very small concentrations of nonporphyrin metals. 

In our study the crude oil came from Shengli Oil Field (Shandong, China). The oil had an acid number of 2.98 mg KOH/g crude oil, a density of 0.9518 g/mL at 25°C, a weight percent of 32.5% for resin, and a weight percent of 4.2% for asphaltenes. In our experiments the crude oil and its fractions used were classified in following categories (1) crude oil, (2) crude oil with asphaltenes removed (deasphaltenes oil), (3) crude oil with petroleum acids removed (deacids oil), and (4) crude oil with both asphaltenes and petroleum acids removed (deasphaltenes and deacids oil). They were treated as described by Shaw and Stapp [61]. 

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