这里 ρ 是比重 (kg/m3), H 是氢原子含量(%wt), S 是硫含量(%wt),N 是氮含量(%wt)。Bitumen 的比重跟氢含量成反比。
此外,他们还进行了其他研究,其结论是:
Bitumen is a mixture of a very large number of components and it is not practical to classify its components by their chemical composition. Consequently, several other criteria are employed to classify bitumen: physical properties, atomic H/C ratio, heteroatom content, boiling cut and solubility.
基于上述结论,油砂人给出下面一段话来表述什么是Bitumen
Crude bitumen is characterized by very high viscosities, high densities, relatively high heavy metal concentrations and a low ratio of hydrogen-to-carbon in comparison with conventional crude oils, with a density range of 970 to 1015 kg/m3 (14 to 8°API), and a viscosity at room temperature generally much greater than 50,000 mPas, NEB (2004)*. Crude bitumen must be treated to convert it into “synthetic crude oil”, SCO, before it can be fractionated in traditional refineries to produce gasoline, heating oils and diesel fuels.
那么,什么是常规石油呢?转一段API的东西:
The definition for Petroleum (Crude oil) is:
"A complex combination of hydrocarbons. It consists predominantly of aliphatic, alicyclic and aromatic hydrocarbons. It may also contain small amounts of nitrogen, oxygen and sulfur compounds. This category encompasses light, medium, and heavy petroleums, as well as the oils extracted from tar sands".
那么,什么是轻重油呢?还是继续转API的东西。如果错了,那也是API错了。
Crude oils may be divided into Light and Heavy crudes on the basis of their gravity. The API gravity is determined as:
°API = (141.5 /Specific gravity)- 131.5
Crude oils with gravity > 33°API are considered as light crudes. Such crudes with a high percentage composition of hydrogen are usually more suitable for processing for gasoline production. Heavy crudes, ie those with gravity < 28°API tend to contain more asphaltenes and are usually rich in aromatics. These heavy crudes require more steps in their processing.
1)我引用的那篇文章中有一个关于轻重油的说法。他们在谈论轻重油时涉及到氢含量,没提碳数,错了吗?你可能也不懂,因为没觉着你是石油化工出身的。
2)你可以在google 上查到一篇石油化工人士发表的技术性文章 Composition and Properties of Heavy Crudes。这篇文章在结论中是这样说的 Heavy crudes are continuous mixtures of mainly hydrogen-poor and heteroatom-rich compounds, spanning a wide carbon number/molecular weight range. 他们也拿氢含量说事。