A fixed-bed hydrogenation reactor and its application method

Abstract

The invention discloses a fixed bed hydrogenation reactor and an application method thereof. In the fixed bed hydrogenation reactor, a gas-liquid phase product pre-separation technology with gas phase withdrawal in an axial center position is employed, wherein a plurality layers of baffle plates are arranged on the inner wall of the reactor, thereby improving operation stability of the hydrogenation system, improving gas-liquid distribution status in the reactor and eliminating wall flow, deflected flow and the like defects. The reactor, when being used in a reaction process of C3 fraction liquid-phase selective hydrogenation to remove methyl acetylene (MA) and propadiene (PD), can not only increase the MAPD hydrogenation purification reaction efficiency of a propadiene material but also is low in residual hydrogen, so that separation load in a down-stream propylene rectification column is reduced.

Description

technical field [0001] The invention belongs to the field of petrochemical industry, and relates to a hydrogenation reactor, more specifically, to a fixed-bed hydrogenation reactor which adopts gas-liquid phase product pre-separation technology and eliminates wall flow and bias flow, and its application. Background technique [0002] After steam cracking and separation of liquid hydrocarbon raw materials such as naphtha, the C3 fraction contains propylene, propane, and a small amount of propyne and propadiene (abbreviated as MAPD). The content of MAPD is about 1% to 5% (volume) . In propylene polymerization, MAPD will reduce the activity of polypropylene catalyst and affect the quality of polymerization grade propylene products. In order to remove MAPD from the C3 fraction, catalytic selective hydrogenation and solvent absorption are currently used in industry to remove MAPD. Due to the simple process of catalytic hydrogenation and no environmental pollution, the applicati...

AI Technical Summary

Problems solved by technology

Although this central gas extraction can reduce heat exchange energy consumption, this gas-liquid separation method uses the opening of the side wall of the reactor to discharge the gas phase, which may easily cause the reaction materials to not pass through the catalyst bed uniformly.

The hydrogen concentration in the catalyst bed is unevenly distributed, resulting in a large amount of wall flow and bias flow, which reduces the hydrogenation efficiency of the catalyst, and cannot remove alkynes and dienes in the olefin refining reaction.

[0011] The use of a gas-liquid distributor can improve the initial uniformity of the gas-liquid two-phase distribution in the upper part of the catalyst bed in the reactor. However, with the expansion of the device scale, the diameter and height of the reactor continue to increase, and it is difficult for the gas-liquid distribution to be in the middle of the catalyst bed. It also forms a uniform distribution to the lower part, and the liquid phase material is easy to form a wall flow on the reactor wall, reducing the reaction efficiency

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