A separation method of naphthalene-enriched liquid based on single-layer porous titania-modified alumina trap

Abstract

The invention provides a separation of naphthalene-enriched liquid based on a single-layer porous titanium dioxide modified trap, comprising the following steps: separating the light fraction distillate and distillate from the first rectification and condensation of the carbon ten heavy aromatic hydrocarbon raw material After the toluene-enriched liquid, vacuum degree, tower top temperature and tower bottom temperature are controlled, and vacuum rectification is carried out. The rectified gas phase is condensed and refluxed, and the uncondensed gas phase is captured by a single-layer porous titanium dioxide-modified alumina trap. Collect and reflux to obtain naphthalene-enriched solution. Among them, the preparation method of the trap is: adding aluminum hydroxide powder into water for hydrothermal reaction, taking it out and drying it to obtain pretreated aluminum hydroxide crystals, and then placing it in a vacuum environment for pyrolysis to obtain flaky alumina powder Add flaky alumina powder to the titanium-containing precursor solution for hydrothermal reaction to obtain alumina powder coated with titanium dioxide; put it into a tube, remove the template and gas through heat treatment, and place it in a vacuum system. A monolayer porous titania-modified alumina trap is formed.

Description

technical field [0001] The invention belongs to the technical field of naphthalene separation, and in particular relates to a method for separating naphthalene-enriched liquid based on a single-layer porous titanium dioxide-modified alumina trap. Background technique [0002] Heavy aromatics refers to the general term of C10 monocyclic, bicyclic or polycyclic aromatic hydrocarbons. Heavy aromatics mainly come from aromatics obtained by catalytic processing or thermal processing, and the main source is the by-product cracking of heavy aromatics from ethylene plants and the reformed heavy aromatics by-products of catalytic reforming. Among them, the reformed heavy aromatics include xylene, propylbenzene, methylethylbenzene, mesitylene, mesitylene, dimethylbenzene, mesitylene, naphthalene, methylnaphthalene, etc. The boiling point of the main components is between 150 and 250 °C , the boiling point of some raw materials is higher than 300°C. At present, the comprehensive util...

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Problems solved by technology

At present, the comprehensive utilization of heavy aromatics mainly includes direct utilization and utilization after separation. Among them, the direct utilization method can be used to prepare solvent oil, extractant, aromatic resin, blended gasoline, etc., and the utilization after separation is the main utilization method of reforming heavy aromatics. The separated commodities can be directly commercialized, the resources are fully utilized, and the utilization rate is high, but the domestic separation technology is not mature

[0003] Methylnaphthalene is an important fine chemical raw material, mainly used in the production of vitamin K, polyester fiber dyeing carrier, fiber dyeing aid, wetting agent, plant growth inhibitor, feed additive, dye dispersant, cement water reducing and 2,6-naphthalene dicarboxylic acid, etc., but the naphthalene-enriched liquid separated and purified from reformed heavy aromatics contains impurities such as naphthalene, α-methylnaphthalene, β-methylnaphthalene, indole, thiazole, etc. affect the purity of the product

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