Heavy oil refining method

Abstract

A refined oil is obtained by using a heavy oil having a hydrogen content of 12 wt % or less as a feed oil, and after carrying out a solvent extraction process such that the hydrogen content increases by 0.2 wt % over that of the feed oil, hydrorefining process is carried out such that the hydrogen content increases by 0.5 wt % over the extracted oil. Thereby, an inexpensive heavy oil can be used as a feedstock, and using a simple and reliable method, refined oil can be produced.

Description

[0001] The present invention relates to a refining method for heavy oil that can efficiently remove impurities derived from a crude oil by a solvent extraction process and a hydrorefining process, and in particular, to a method that can obtain a refined oil that is suitable as a feedstock for light olefin production from a heavy oil that could not be conventionally used as feedstock for light olefin production.[0002] Because of the presence of impurities originating from the source of the crude oil, oil products that have crude oil as a starting material are produced by implementing various types of physical and chemical refining processes, starting with atmospheric fractional distillation.[0003] Generally, distillate, that is, distillated oils drawn off from a tower by distillation, have minute amounts of the impurities and these impurities can be removed by a simple refining process. Thereby, they can be used s for automobile fuel, gas turbine fuel, petrochemical feedstock, or the...

AI Technical Summary

Benefits of technology

[0009] As a result of significant research to attain the object described above, the inventors have discovered that impurities in heavy oil can be efficiently removed to obtain a high quality refined oil having impurities removed to a high degree by using as a feedstock a heavy oil having a hydrogen content of 12 wt % or less, processing the heavy oil so that the hydrogen content is increased by a certain amount or greater by using a solvent extraction, and then processing the obtained deasphalted oil so that the hydrogen content is increased by a certain amount or greater by using a hydrorefining process.

Problems solved by technology

In contrast, residue oils, that is, bottom oils remained at a tower by distillation, have impurities concentrated and they exist in a state that makes them extremely difficult to remove.

In the case of a particularly high degree of refining, severe reaction conditions including high temperature and high pressure in the presence of hydrogen and a catalyst are necessary, a large amount of hydrogen and catalyst are consumed, and large investments including facilities expenses are necessary.

Thus, at present this is not economical.

Vacuum gas oil, whose molecular weight is higher than naphtha and contains much sulfur, is used as a feedstock for an ethylene plant, and is considered to be the limit for commercial operation.