A combined method for diesel hydrotreating and upgrading

Abstract

The invention relates to a diesel oil hydroupgrading combination method, which includes: firstly subjecting high quality diesel oil and recycle hydrogen from a cold high pressure separator to mixing heating and then making them react in a first hydrofining reactor, subjecting the obtained hydrofining material flow to heat transfer cooling, then bringing the material flow into the cold high pressure separator to undergo gas-liquid separation so as to obtain a gas phase material and a liquid material; subjecting the gas phase material to desulfurization in a desulfurization system, raising the pressure of the desulfurized hydrogen by a compressor, then subjecting the hydrogen and lower quality diesel oil to mixing heating and making them react in a second hydroupgrading reactor, conducting heat transfer cooling on a reaction product, then letting the product enter a cold high pressure separator, taking the separated gas phase material as recycle hydrogen and bringing it into the first hydrofining reactor, letting the liquid material mix with a liquid material from the high pressure separator and enter a low pressure separator, subjecting the obtained liquid product to fractionation in a fractionating tower so as to obtain gas, naphtha and diesel oil. The method only requires the first hydrofining reactor has a desulphurization rate meeting the requirement, thus reducing the investment and hydrogen consumption; and the second hydroupgrading reactor can ensure an enough high cetane number.

Description

technical field [0001] The invention relates to a combined method for hydrogenation and upgrading of diesel oil. Background technique [0002] Catalytic cracking has the characteristics of wide range of raw material adaptability and good economy, and has been widely used in China, but its diesel oil quality is poor (high content of sulfur, nitrogen and aromatics, low cetane number), and storage stability is poor. On the other hand, in order to protect the environment, increasingly stringent environmental protection regulations put forward higher requirements on the quality of diesel products, limiting the sulfur content, aromatics content and cetane number. In addition to catalytic diesel, general refineries also have a large number of diesel components of different qualities such as straight-run diesel and coker diesel. In order to meet the new quality standards, oil refineries must build new diesel hydrogenation units to economically Reasonable hydrofining or upgrading. ...

AI Technical Summary

Problems solved by technology

For small-scale refineries, building two sets of small-scale hydrogenation units requires a large investment; building a set of hydrogenation units needs to be designed according to poor-quality conditions. Good-quality diesel has the problem of excessive hydrogenation, and hydrogen consumption Large volume, economically unreasonable

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