A treatment method for oil-containing waste catalyst discharged from ebullated bed

Abstract

A processing method of an oil-containing waste catalyst discharged from a fluidized bed is disclosed. According to the method, the oil-containing waste catalyst is processed by adoption of two-stage extraction reactors which are connected in series; firstly the oil-containing waste catalyst is directly fed into the first-stage extraction reactor, light hydrocarbons in effluent gas of a cold-high pressure separator of the fluidized bed is adopted as a first-stage extractant, the first-stage extractant and the oil-containing waste catalyst are in contact and subjected to a supercritical extraction reaction, the obtained extract after the reaction is separated to obtain the first-stage extractant and light oil, and the obtained extraction residue is fed into the second-stage extraction reactor; and one or more selected from gasoline obtained by a fractionating system of the fluidized bed, diesel oil obtained by the fractionating system and the light oil obtained by separation of the first-stage extract is adopted as a second-stage extractant, the obtained extract after the reaction is fed into a fractionating system of a fluidized bed reactor or returns to the fluidized bed reactor, and the obtained extraction residue is the waste catalyst. The method can achieve efficient separation of the waste catalyst by utilization of products and properties of a fluidized bed system itself.

Description

technical field [0001] The invention relates to a catalyst treatment method, in particular to a treatment method for oil-containing waste catalyst discharged from a fluidized bed. Background technique [0002] Among the current residual oil hydrogenation processes, the fixed bed residual oil hydrogenation and ebullating bed residual oil hydrogenation technologies are the most mature. In the fixed-bed residue hydrogenation process, the catalyst bed in the fixed-bed reactor is fixed, and the residue raw material and hydrogen are mixed into the reactor from the upper or bottom of the reactor (UFR process), and the hydrogenation is carried out under the set reaction conditions. hydrogen reaction. In the late stage of the reaction, when the device is finished running, in order to avoid the problem of directly stopping the feed, resulting in the remaining unreacted residual oil in the catalyst bed, making it difficult to unload the catalyst, it is generally adopted to add some li...

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Problems solved by technology

Hydrothermal desorption is to use a large amount of hot water to wash the catalyst particles containing waste oil. Since the catalyst discharged from the fluidized bed contains a large amount of unconverted residual oil, and the solubility of hot water to the residual oil is very low, the washing effect is very poor and causes Secondary pollution of water. Secondly, the introduction of water as a solvent in this patent needs to be separated out in the downstream separation equipment, which virtually increases the complexity and operating costs of the device. Therefore, when treating ebullating bed catalysts containing a large amount of unconverted residue When, there are some questionable places in this patent method

[0004] In CN1669960A, US19960696809 and other patent applications involving hydrothermal desorption, there are certain problems in oil recovery after hydrothermal desorption and solid catalyst drying treatment. For example, after hydrothermal desorption of oily solid waste, Only the desorbed mixture (light oil, water, waste solids) can be separated by natural sedimentation. To achieve good separation efficiency, the sedimentation time must be prolonged, which causes problems such as long time consumption and large equipment footprint.

[0005] From the above, it can be seen that there is no good treatment method for the separation of oily waste catalyst discharged from the fluidized bed at present.

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