System for treating chloroaluminate ionic liquid spent catalyst and alkaline wastewater

Abstract

The invention provides a system for treating a chloroaluminate ionic liquid spent catalyst and alkaline wastewater. The system comprises a hydrolysis reactor, a neutralization reactor, a flocculationsedimentation system, a mechanical dehydration device and a drying device, wherein the hydrolysis reactor is used for mixing the chloroaluminate ionic liquid spent catalyst with strong brine for hydrolysis reaction; the neutralization reactor is connected to the hydrolysis reactor and is used for mixing acidic hydrolysate generated by hydrolysis reaction with alkali liquor containing the alkalinewastewater for neutralization reaction; the flocculation sedimentation system is connected to the neutralization reactor and is used for fully mixing neutralization liquid generated by neutralizationreaction with a flocculant and carrying out sedimentation separation; the mechanical dehydration device is connected to the flocculation sedimentation system and is used for dehydration treatment of concentrated flocs formed by sedimentation separation; and the drying device is connected to the mechanical dehydration device and is used for drying wet solid residues formed by dehydration treatment.The system can softly eliminate the activity of the spent catalyst, and has good stability and safety of operation.

Description

technical field [0001] The invention belongs to the technical field of petrochemical industry, and in particular relates to a system for treating waste catalysts of chloroaluminate-based ionic liquids and alkaline waste water. Background technique [0002] As the national clean oil product upgrading strategy enters the accelerated promotion period, as an ideal blending component of clean gasoline, the demand for high-octane alkylated oil ushered in explosive growth. Catalytic alkylation using C4 as raw material is the main process for the production of alkylated oil. Most of the existing alkylation processes use two traditional process routes: hydrofluoric acid method and sulfuric acid method. However, the above-mentioned traditional process route uses hydrofluoric acid and sulfuric acid as catalysts, which not only causes huge safety hazards to the process, equipment and personnel, but also creates a large amount of "waste acid slag" and alkali-containing wastewater dischar...

AI Technical Summary

Problems solved by technology

The above-mentioned method and system can harmlessly treat the spent chloroaluminate-based ionic liquid catalyst to a certain extent and realize the recycling of metals and acid-soluble oil in the spent catalyst. There are still the following defects: 1) directly adding alkali in the digestion reactor to digest-neutralize the spent catalyst, the reaction process is very violent, and the stability and safety of the process and system are relatively poor; 2) acid soluble in the spent catalyst Oil easily causes carbonization in digestion-neutralization reaction process, and the rate of recovery of acid-soluble oil is lower than 70%, and the water content of the acid-soluble oil that reclaims obtains in addition is high (moisture rate is about 7%), and there is particulate carbon impurity ( The content of particulate carbon impurities is about 5%), and the quality of the oil product is poor; 3) the waste catalyst is digested-neutralized to obtain a three-phase mixture composed of water phase / acid-soluble oil phase / floc, which is recovered after recovery When acid-soluble oil needs to break the emulsified oil, it is not conducive to subsequent treatment; 4) The metal and acid-soluble oil in the spent catalyst are recovered by two flocculation and two dehydration methods, the process is relatively complicated and the operation cost is high

At present, the alkali washing wastewater is usually discharged to the sewage treatment system for treatment. Not only does it need to be neutralized by adding a large amount of exogenous acids, but also a large amount of physicochemical sludge containing aluminum hydroxide will be added after neutralization. The salt load and organic load of the treated wastewater are high, which poses a serious impact on the stable operation of the sewage treatment system

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