Residual oil hydrotreating method

Abstract

The invention discloses a residual oil hydrotreating method. According to the method, under hydrotreating conditions, a residual oil raw material and hydrogen pass through at least 4 reactors connected in series in order, all the reactors except the last one are provided with a protective agent and a demetallization catalyst, and along the material flowing direction, the ratios of the protective agent and the demetallization catalyst decrease gradually in the downstream reactors. After the equipment operates for 700-4000h, shunt operation is carried out. The feeding amount of a first reactor is reduced or maintained constant. The feeding amount of each reactor between the first reactor and the last reactor is increased, and the increased residual oil raw material is injected at the inlets of the middle reactors. Compared with the prior art, the method provided in the invention can obviously prolong the operation period of residual hydrogenation equipment, and make the effective utilization rate of the catalyst and the equipment running time achieve consistency, thereby enhancing the equipment running efficiency and improving the economical efficiency.

Description

technical field [0001] The invention relates to a residual oil hydrogenation method, which is suitable for the hydrogenation treatment process of heavy residual oil, especially the hydrogenation treatment process of fixed bed heavy residual oil. Background technique [0002] As crude oil becomes heavier and inferior, and environmental protection regulations become increasingly stringent, fixed-bed hydroprocessing technology is the main method for upgrading residue oil. It is widely used and has mature technology. It can be combined with heavy oil catalytic cracking unit to make residue oil lighter. Prolific transportation fuel oil. Heavy raw oil contains a large amount of sulfur, nitrogen, oxygen, nickel, vanadium and other heteroatoms, unsaturated hydrocarbons, macromolecular colloids and asphaltenes. The reaction process of residual oil hydrotreating is complex and changeable, the raw material structure is complex, and the molecular weight distribution is broad. To compl...

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Problems solved by technology

The problem with this technology is that, according to the technical key disclosed in this patent, when the pressure drop of at least one bed in the first hydrogenation reaction zone reaches the upper limit or after a hot spot appears in the zone, the pressure drop to the second hydrogenation reaction zone The amount of residual oil directly introduced is bound to be lower than the original feed amount, which is equivalent to the reduction operation

By reducing feedstock oil, especially residual oil feed, the utilization rate of the catalyst is improved and the operation period of the unit is extended. However, in the catalyst loading method in this technology, since the protective agent and demetallization catalyst are loaded in the second hydrogenation reaction zone, Weaken the utilization rate of the initial reactor, adjust the operation mode after the catalyst generates hot spots or the bed pressure drop reaches the upper limit, and it cannot guarantee that the hot spots will be effectively controlled

In the partition operation provided by the invention, it can be predicted that the average reaction temperature of the second reaction zone will be much higher than the average reaction temperature of the first reaction zone. According to the process given by the invention, the reaction temperature required by the second zone cannot be reached. And then can't realize the operation described in the invention, then the shortcoming that this scheme exists is obvious

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