The primary difference between bitumen and ordinary crude is the size of the hydrocarbon molecules: in liquid oil, these molecules contain between five and twenty carbon atoms, while in bitumen they contain more than twenty. (At room temperature, pure bitumen is so viscous that it will not flow.) The main job of the upgrader is to break down the oversized hydrocarbons into smaller units.

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Indeed, the Anglo-Dutch multinational announced today that it had inked an agreement to acquire Koch Materials China , which is involved in the manufacture and marketing of bitumen--that black viscous residue taken from the distillation of crude petroleum--in the country.

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Bitumen is so low in capacity to produce gasoline and so viscous and dense, it cannot be processed directly.

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