Properties of naphthalene in coal tar

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This post was last edited by jordan569 on 2013-1-6 at 22:39. Chinese name: Naphthalene (15.32%); Chinese synonyms: Naphthalene; Diphenyl; Benzene; Crude naphthalene; Cycloalkane; Refined naphthalene; Naphthalene pellets; Coal tar camphor. English name: Naphthalene; English synonyms: ‘LGC’ (2402); ‘LGC’ (2603); 1-NAPHTHALENE; TAR CAMPHOR; NAPTHALENE; NAPTHALIN; NAPHTHENE; NAPHTHALENE. CAS number: 91-20-3; Molecular formula: C10H8; Molecular weight: 128.17; Melting point: 80–82 °C (literature value); Boiling point: 218 °C (literature value); Density: 0.99; Vapor density: 4.4 (vs air); Vapor pressure: 0.03 mm Hg (at 25 °C); Refractive index: 1.5821; Flash point: 174 °F; Storage conditions: APPROX 4°C; Water solubility: 30 mg/L (at 25 °C); Chemical properties: Colorless, shiny monoclinic crystals. It has a strong tar smell. It sublimes easily at room temperature. Insoluble in water, soluble in ether, ethanol, chloroform, carbon disulfide, benzene, etc. Uses: It is used as a solvent and analytical reagent, as well as in organic synthesis. It is employed in the production of pharmaceuticals, pesticides, fragrances, dyes, and rubber antioxidants. It is mainly used to produce phthalic anhydride, and it also serves as a raw material for the manufacture of dyes, pharmaceuticals, etc. Naphthalene is a raw material in pesticide production; it can be used to create naphthol and ethyl naphthol, or it can be oxidized to phthalic anhydride, from which phthalimide can be produced. It can also react with chloroacetic acid to form naphthalene acetic acid. It can be used as an intermediate for insecticides such as imidacloprid and methomyl, herbicides such as mesotrione and diuron, and plant growth regulators such as naphthaleneacetic acid and naphthoxyacetic acid. Use: Used for preventing mold and corrosion in leather. Uses: It is primarily used in the production of phthalic anhydride, and it also serves as a basic raw material for the manufacture of dyes, pharmaceuticals, plastics, etc. It can be used to produce dye intermediates, dispersants, water reducers, and other products. Crude naphthalene is refined into pure naphthalene using clay. Production method: The preparation method involves using high-temperature coal tar (with naphthalene accounting for about 8%–12%). After distilling the tar to remove the light oil fraction and the phenol oil fraction, the fraction at 210–230°C is collected, thereby obtaining the naphthalene oil fraction. By using the cooling crystallization method on naphthalene oil fractions, crude naphthalene with a naphthalene content of 75% can be obtained. This crude naphthalene is then filtered, dried, and pressed to yield compressed blocks with a naphthalene content of 96%–98%. The compressed naphthalene is melted, washed with sulfuric acid for purification, neutralized with 10% sodium hydroxide to remove phenols, and water is distilled off. The fraction obtained at 100–130°C is collected, and finally the product is obtained through crystallization. If it is produced from petroleum hydrocarbons, its raw materials come from catalytically reformed heavy oil, catalytic cracking recycled oil, and the tar by-product of ethylene production. . Note $ # , $ $