Method for producing clean oil product through liquid-phase product cyclic hydrogenation

Abstract

The invention discloses a method for producing clean oil product through liquid-phase product cyclic hydrogenation. The method comprises the steps that: part of a liquid-phase product of a hydrogenation reaction is circulated and mixed with fresh raw materials and hydrogen; heat exchange is carried out, and the mixture is delivered into a pretreatment reactor; the mixture is subjected to hydrogen dissolving saturation, olefin hydrogenation reaction, and removing of sulfur, nitrogen, residual carbon, metal and colloid, such that a liquid-phase mixed material comprising saturated dissolved hydrogen is formed; the obtained liquid-phase mixed material is subjected to a hydrogenation reaction in a hydrogenation main reactor section by section; a liquid-phase product obtained from the bottom of the hydrogenation main reactor is divided into two flows, wherein one flow is circulated and is mixed with raw material oil and hydrogen, and the other flow is discharged from the hydrogenation main reactor and enters a subsequent separation device. The pretreatment reactor adopted by the invention has the functions such as hydrogen dissolving, raw material impurity-removing, and the like. With the pretreatment reactor, the material entering the hydrogenation main reactor is in a liquid phase, such that a deactivation rate of a hydrogenation catalyst can be effectively reduced, hydrogenation reaction efficiency can be improved, catalyst service life can be prolonged, and raw material adaptability can be improved.

Description

technical field [0001] The invention relates to a method for producing clean oil by circulating hydrogenation of liquid-phase products, in particular to a method for producing clean oil by increasing the amount of dissolved hydrogen and increasing the efficiency of hydrogenation reaction through the circulation of liquid-phase products. Background technique [0002] Catalytic hydrogenation is one of the most effective methods for deep removal of impurities such as sulfur, nitrogen, oxygen and metals in raw materials. Currently, the most mainstream hydrogenation technology is the gas phase cycle hydrogenation process. In this process, in order to control the reaction temperature of the catalyst bed and avoid catalyst deactivation due to carbon deposition, a larger hydrogen-to-oil ratio is usually adopted. After the hydrogenation reaction is completed, a large amount of rich hydrogen is pressurized by the circulating hydrogen compressor and mixed with new hydrogen to continue...

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Problems solved by technology

A large number of stripping trays are installed in the patented reactor, resulting in a decrease in the effective use volume of the reactor, and at the same time increasing the workload of loading and unloading the catalyst in the post-skimming treatment

Chinese patent CN 101724443A discloses a two-phase hydrogenation treatment method for distillate oil, in which raw materials, hydrogen and recycled hydrogenated products are saturated with hydrogen in a pre-saturated high-pressure tank to form a two-liquid phase mixture of raw materials / hydrogenated products / hydrogen , the hydrogen in the liquid phase mixture is separated, and the saturated dissolved hydrogen mixture passes through a single-stage or multi-stage internal cross-flow reactor, although the dissolved hydrogen and H 2 S, NH 3 and other harmful gas release problems, but the structure of the cross-flow reactor is complex, the bottom of the reactor is equipped with a cross-flow stripping zone, the volume of the reactor is large, and the operation process is complicated

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