Pretreatment method and system for fraction oil for production of alkylbenzene

A system for pretreatment of a fraction oil for the production of alkylbenzene, characterized in comprising a neutralization reaction unit, an extraction unit, an extraction agent recovery unit, and an adsorption unit which are connected in sequence,

• wherein the neutralization reaction unit is set up with a fraction oil inlet, a water injection port, a base solution inlet, an inorganic salt solution inlet, a neutral fraction oil outlet, and an emulsion phase and water phase outlet;
• the upper part of the extraction unit is connected with an extraction agent conveying pipeline;
• the middle part of the extraction unit is connected with the neutral fraction oil outlet of the neutralization reaction unit:
• the bottom of the extraction unit is connected with an inlet of the extraction agent recovery unit;
• and the top of the extraction unit is connected with an inlet of the adsorption unit;
• the top of the extraction agent recovery unit is connected with oxygen-containing compounds discharge pipeline, and the bottom of the extraction agent recovery unit is connected with an extraction agent conveying pipeline;
• the top of the adsorption unit is connected with an alkylation reactor.