Method for coproducing 1-naphthol and 2-naphthol by direct alkali fusion of naphthalene sulfonation product

Abstract

The invention discloses a method for cooperatively producing 1-naphthol and 2-naphthol from a naphthalene sulfonation product by virtue of direct alkali fusion. The method comprises the following steps: performing multiple sulfonation reactions on naphthalene and concentrated sulfuric acid, directly performing an alkali fusion reaction on the obtained liquid sulfonation product and sodium hydroxide in a molten state, and then diluting, acidifying, boiling for layering, dehydrating and drying, rectifying and separating, thereby obtaining high-purity 1-naphthol and 2-naphthol simultaneously. The steps of hydrolyzing, naphthalene blowing, neutralization, cooling and crystallization and filtration of sulfonation products, and feeding for performing alkali fusion on a water-containing filter cake at a normal temperature in the existing process are avoided; no filtration wastewater difficult to treat is not generated anymore, the energy source and the resources are saved, the yield is increased and the operating environment is improved; as a result, the problems of three-waste treatment during naphthol production are thoroughly solved from the production process.

Description

technical field [0001] The present invention relates to a kind of preparation method of coproduction 1-naphthol and 2-naphthol, especially relate to a kind of naphthalene sulfonation product directly and molten sodium hydroxide to carry out alkali fusion reaction coproduction 1-naphthol and 2-naphthol The method of phenol is also a clean production method of naphthol without waste water. technical background [0002] 1-Naphthol, commonly known as methylnaphthol, also known as α-naphthol, is currently mainly used as an intermediate for the pesticide carbaryl, and can also be used as an intermediate for some drugs and fine chemical products. Its production mainly adopts naphthalene nitration, reduction, and hydrolysis methods. Since about 4% of 2-nitronaphthalene is produced during nitration, the general product content is about 96%, so it is necessary to obtain a content that meets the national standard GB / T3410-2002 to reach 99.5% % of high-quality product 1-naphthol needs ...

AI Technical Summary

Problems solved by technology

This patent consumes the acid mother liquor of 1-naphthalenesulfonic acid through high-temperature sulfonation synthesis of 2-naphthalenesulfonic acid, but a large amount of mother liquor wastewater after neutralization and crystallization of 2-naphthalenesulfonic acid still cannot be solved; the acid mother liquor of 1-naphthalenesulfonic acid is in Separation at 5°C requires high energy consumption, and the concentration of the acid mother liquor is low, which seriously corrodes the equipment; separately preparing 1-naphthalenesulfonic acid and 2-naphthalenesulfonic acid and entering into the processes of neutralization, filtration and alkali fusion respectively, resulting in cumbersome operations , repeated investment

[0007] In addition to their own inherent defects, the above-mentioned various process methods all present the common shortcomings of a large amount of filtered wastewater that is difficult to treat, complex procedures, long process flow, and high energy consumption.

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