RU-2861448-C1 - METHOD FOR PRODUCING TRANS-1,2-CYCLOHEXANEDIOL FROM CAPROLACTAM PRODUCTION WASTE

Abstract

FIELD: chemical industry. SUBSTANCE: invention relates to the field of producing naphthene diols - trans-1,2-cyclohexanediol, which is used in various areas of chemical production: in the synthesis of synthetic rubber stabilisers, for gelling organic liquids, in the production of medicines and fragrances, being an intermediate product in many syntheses. The method includes hydrolysis of cyclohexene oxide contained in the composition of the alcohol fraction, as well as isolation of the resulting crystalline trans-1,2-cyclohexanediol and a heteroazeotrope of the alcohol-containing fraction with water. Next, the heteroazeotrope is separated into a mixture of oxygen-containing compounds, including n-amyl alcohol and water, recycled back to the production of trans-1,2-cyclohexanediol. Wherein, the raw material used is a by-product of caprolactam production, and the process is carried out in the liquid phase with hot water at a temperature not exceeding 95°C. The volume ratio of the caprolactam alcohol fraction to water can vary from 1:2 to 1:20, and the feed rate of the caprolactam alcohol fraction is 6 g/min. EFFECT: obtaining a pure target product from production waste. 2 cl, 1 tbl, 2 ex

Inventors

• GOLOVANOV ALEKSANDR ALEKSANDROVICH
• Bakharev Petr Nikolaevich
• Odin Ivan Sergeevich
• TSVETKOVA IRINA VASILEVNA

Dates

Publication Date

20260505

Application Date

20250507

Claims (2)

1. 1. A method for producing trans- 1,2-cyclohexanediol, comprising hydrolysis of cyclohexene oxide contained in the alcohol fraction of caprolactam, isolation of the resulting crystalline trans- 1,2-cyclohexanediol and a heteroazeotrope of the alcohol-containing fraction with water, followed by separation of the heteroazeotrope into a mixture of oxygen-containing compounds, including n-amyl alcohol and water recycled into the production of trans -1,2-cyclohexanediol, characterized in that a by-product of caprolactam production is used as raw material, the process is carried out in the liquid phase with hot water at a temperature of no more than 95°C, the ratio of the alcohol fraction of caprolactam and water can vary by volume from 1:2 to 1:20, the feed rate of the alcohol fraction of caprolactam is 6 g/min.
2. 2. The method according to paragraph 1, characterized in that all transformations occur in the initial alcohol fraction of caprolactam and are accompanied by the release of pure crystalline trans -1,2-cyclohexanediol.

Description

The invention relates to the production of naphthenic diols from the alcohol fraction of caprolactam containing cyclohexene oxide (OCH). Trans -1,2-cyclohexanediol ( trans- 1,2-CHD) finds wide application in various fields of chemical production: in the synthesis of synthetic rubber stabilizers, for the gelatinization of organic liquids, and in the production of pharmaceuticals and fragrances, serving as an intermediate product in many syntheses. The hydrolysis of OCH, combined with the subsequent isolation of crystalline ( trans -1,2-CHD), leaves an alcohol fraction containing predominantly n -amyl alcohol at a higher concentration than the original. A known method for processing waste in the production of caprolactam to obtain a mixture of esters, for example, a method for producing esters of carboxylic acids (Patent of the Russian Federation No. 2283299, published 2003.06.27, C07C 87/08, C07C 69/80). This invention describes a method for producing esters by esterification of a mixture of mono- and dicarboxylic acids C 2 -C 6 , obtained by evaporation of aqueous acidic wastewater from caprolactam production, on acid catalysts, in the presence of a third component (benzene) at a temperature of 80-90 °C until complete cessation of water evolution. A disadvantage of the known method is the need to introduce a third component (benzene), which also complicates further rectification distillation. A method for producing esters from caprolactam production waste is known (RU Patent No. 2422434, 18.01.2010 C07C 69/02), C07C 67/03, C07C 69/06, C07C 69/14), namely the alcohol fraction of caprolactam. The method for producing esters from caprolactam production waste is carried out by the esterification reaction of an organic acid and an alcohol at a temperature of 40–130°C using a cation exchange resin in acid form as a catalyst in an amount of 0.4–2.0 wt. % of the weight of the loaded raw material with cooling of the reaction mixture before phase separation. The presented methods for processing the alcohol fraction, which is a waste product of caprolactam production, involve obtaining a mixture of esters, with the formation of a two-phase system and subsequent rectification. The proposed method for processing the alcohol fraction of caprolactam, which contains predominantly n -amyl alcohol and OCG, is based on the conversion of OCG to trans -1,2-CHD, which is isolated from the reaction mixture by crystallization. The remaining n -amyl alcohol is recycled. The proposed method is simple, compact, and cost-effective. A method for obtaining is knowntrance-1,2-CHD or its alkyl derivatives(Patent RF 2069653, C07C 29/03(2006.01), C07C 35/14(2006.01) published 11/27/1996) by the interaction of cyclohexene with hydrogen peroxide in the presence of 0.09–0.4 mol/l H2MoO4and tributyloctylammonium bromide (TBOAB) at a ratio of molybdic acid and TBOAB (2:1) ± (20:1) and a temperature of 65–70°C. The reaction product is isolated by salting out and then distilled. The reaction duration is 3 h, the yieldtrance-1,2-CHD based on cyclohexene 94%, on H2ABOUT2- 50%. Receipt is also offered.trance-1,2-CHD is carried out in a two-phase system containing an organic (cyclohexene) and an aqueous phase (a solution of tungstate and a quaternary ammonium salt). The resultingtrance-1,2-CHD is concentrated in the aqueous phase. The yield of the product is 99% based on cyclohexene, and 99% based on H2ABOUT2- 78%. The target product is isolated from the aqueous phase by evaporation and subsequent distillation. A method is known for producing trans- 1,2-CHD (USSR AC 470513 C07C 35/14 (2006.01), C07C 31/20 (2006.01) published on 05.15.1975) in the presence of heterogeneous cyclohexene oxidation catalysts, which are a mixture of MoO 3 and MnSO 4 or MgSO 4 at a ratio in mass % of MnO 3 or MgSO 4 equal to 5:0.1–1.5 based on hydroperoxide. The catalyst is recommended to be taken in an amount of 6 mass % based on hydroperoxide. It is advisable to carry out the hydrolysis of OH in the vapor phase at 280–320°C and a feed rate of the sum of the components of 0.1–0.15 h –1 . OCG and water are mixed in a ratio of 3–4 volumes of water to 1 volume of OCG, passing the mixture through a glass or enamel reactor filled with quartz packing. OCG undergoes quantitative hydrolysis to form trans- 1,2-CHD. The yield of trans- 1,2-CHD, with a melting point of 104°C, is 95.2%. A disadvantage of this method is the isolation and transfer of the intermediate product (OCG) for hydrolysis to a separate hydrolysis reactor, which is carried out in the vapor phase at high temperature and with a large excess of water. The closest to the proposed method in terms of technical essence and the achieved result is the method for obtaining trans- 1,2-CHD by hydrolysis of OCH. Hydrolysis is carried out by heating in water at a temperature of 100 to 140°C without the use of a catalyst [Q. Yang, X. Yang, Y. Wang, H. Wang, Q. Cheng. Research on Chemical Intermediates, 2012, Vol. 38, Pp. 2277–228