Method for producing clean diesel by full liquid phase hydrogenation

Abstract

The invention relates to a method for producing clean diesel by full liquid phase hydrogenation. The method comprises the following steps that: raw materials, hydrogen and a circulating liquid hydrogenated product are subjected to hydrogen saturation in a pipeline to form a liquid-phase raw material / hydrogenated product / hydrogen mixture; under a hydrogenation process condition, the liquid-phase mixture with saturated dissolved hydrogen sectionally enters a multi-stage conventional hydrogenation reactor. According to the present invention, with the hydrogenation reactor, the hydrogenation reaction is catalyzing, the reaction by products such as H2S and NH3 are discharged out of the reaction system; the materials contacting the solid-phase catalyst are the liquid-phase reaction materials so as to improve the hydrogenation reaction efficiency; the method does not require the hydrogen circulating so as to substantially reduce the equipment investment and the operation cost; the method provided by the present invention can be used in hydrogenation, desulfurization, denitrogenation and dearomatization refinement for poor-quality diesel fuel fractions, and can be applicable for the technical process for producing high-quality clean diesel by using the fraction oil such as VGO raw material mild hydrocracking.

Description

technical field [0001] The invention relates to clean fuel production technology, and is a method for producing clean fuel by fixed-bed hydrogenation, in particular, a method for producing clean diesel by fixed-bed full-liquid-phase hydrogenation. Background technique [0002] The sulfur content of crude oil supplied in the global crude oil market tends to be higher. Sulfur must be removed during the refining process in order for the various end products to meet specification requirements. In order to solve the difficulties caused by deep desulfurization, various companies and research departments around the world have developed a variety of methods: replace the current catalyst with a catalyst with higher activity; increase the operating temperature; increase the purity of hydrogen or increase the partial pressure of hydrogen; improve the reactor; improve Catalyst bed feed distribution; removal of hydrogen sulfide from recycle gas, etc. Without exception, these measures w...

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Problems solved by technology

[0008] U.S. Patents US6213835, US6428686, etc. disclose a hydrogenation process for pre-dissolving hydrogen, which increases the amount of dissolved hydrogen by circulating hydrogenated oil, but it does not solve the problem of H 2 S, NH 3 The problem of removal of harmful impurities, such as harmful impurities, leads to their continuous accumulation in the reactor, which greatly reduces the reaction efficiency

[0009] Chinese patent CN101724443A discloses a two-phase hydrogenation treatment method for distillate oil. The raw material, hydrogen and circulating hydrogenation products are saturated with hydrogen in a pre-saturated high-pressure tank. Under the hydrogenation process conditions, the saturated dissolved hydrogen mixture passes through a single stage or Although the multi-stage internal cross-flow reactor avoids the hydrogen circulation link, the structure of the cross-flow reactor is complicated, and a cross-flow stripping zone is set at the bottom of the reactor, the reactor volume is large, and the operation process is complicated

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