Boiling bed hydrogenation reaction system and boiling bed hydrogenation process method

Abstract

The invention belongs to the technical field of hydrogenation, and particularly relates to a boiling bed hydrogenation reaction system and a boiling bed hydrogenation process method. On one hand, theproblem of coking of parts of pipelines caused by intermittent operation of a catalyst discharge system can be effectively solved. On the other hand, the use ratio of a reactor can be further increased (namely, reserve of catalysts in the reactor is improved), hydrogenation reaction effects are further improved, operating stability of the system is improved, and particularly, stable boiling stateof the catalysts can be maintained in start, in stop and under unusual service conditions.

Description

technical field [0001] The invention relates to a fluidized bed hydrogenation reaction system and a fluidized bed hydrogenation process, belonging to the technical field of hydrogenation. Background technique [0002] Ebullated bed hydrogenation reaction refers to the process of hydrogenation reaction of feedstock oil (mainly in liquid phase) and hydrogen (gas phase) on catalyst (solid phase). Hydrogenation reaction mainly occurs in hydrodesulfurization, hydrodenitrogenation and hydrodeoxygenation , hydrogenation saturation, hydrocracking, etc. The reactor operates in the boiling state of gas, liquid and solid. The catalyst is in a boiling state driven by the raw material oil and hydrogen entering from the bottom of the reactor, which is in a completely different fluid state from the fixed bed reactor. The ebullating bed hydrogenation reaction can process low-quality feed oil with high metal and high asphaltene content. The reaction has the characteristics of small pressure...

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Problems solved by technology

[0005] One type is to adopt the mode of oil phase circulation, such as the fluidized bed process described in USRe25,770. The deficiency of this process in practical application is: in order to maintain the liquid-solid separation effect, the amount of catalyst in the reactor should not be too much, and the reactor should use Low efficiency, the utilization rate of industrial ebullated bed reactors is generally only about 40% - the utilization rate generally refers to the percentage of catalyst loading in the reactor volume (excluding head space), and the utilization rate of fixed bed reactors is generally above 90%; There is a large space so that the residence time of the liquid material is too long without catalytic conditions, there is no hydrogenation reaction in this part, and the material is easy to react and coke at high temperature

[0006] Another kind is to arrange three-phase separator in the reactor, carry out gas-liquid-solid separation in the upper part of the reactor, as the ebullating bed reactor that CN02109404.7 introduces, by arranging built-in three-phase separator according to this scheme, can Increase the amount of catalyst, that is, increase the utilization space of the reactor, but in actual use, the increase in the amount of catalyst is limited. If the amount of catalyst increases, the separation effect of the three-phase separator will drop rapidly, and it is actually more efficient than the first type of ebullating bed reactor. The improvement of the efficiency is limited; CN200710012680.9 has further improved the above-mentioned technology. A guide structure is set at the lower part of the three-phase separator, and the guide structure is used to increase the operating flexibility of the three-phase separator, ensure the efficient separation of the three-phase separator, and reduce the catalyst. The amount of carry-over can increase the amount of catalyst storage and the utilization rate of the reactor, but when in use, it is still necessary to set a catalyst dilute phase zone in a certain area at the lower part of the three-phase separator (as shown in the attached figure, the amount of catalyst in this area is very small, basically hydrogenation reaction does not occur), otherwise the separation effect of the three-phase separator still cannot meet the requirements, and the existence of the dilute phase zone will affect the further improvement of the utilization rate of the reactor (although it is pointed out in the specification that the catalyst loading in the reactor cylinder can be 40% to 70% of the reactor volume, but generally only about 50% of the situation can be stable), which also affects the hydrogenation reaction effect, and after the scale of the reactor is enlarged, it is more difficult to increase the catalyst loading, and it is difficult to achieve The effect of the experimental setup

[0007] Although the latter theoretically does not require circulating oil, it will make it difficult for the catalyst to reach a stable boiling state during start-up, shutdown, and abnormal operation, resulting in insufficient operational stability.

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