CS242202B1 - Process of treating the mixture of esters, acids and water - Google Patents

Abstract

The invention provides a suitable method for processing a mixture of esters, acids and water, arising in the process of cyclohexanone production. From the stage of separation of the mixture of esters, acids and water at atmospheric pressure and a temperature of 20 ° - 110 ° C, the aqueous phase is recycled to the stage of acid hydrolysis of cyclohexanol esters and the organic phase is recycled to the stage of acid hydrolysis of cyclohexanol esters and the organic phase with a water content of 10 - 20% by weight is injected into a dewatering column. The method of the stage of the invention improves the energy balance of cyclohexanone production and allows the use of organic acids in the stage of acid hydrolysis of cyclohexanol esters.

Description

The present invention provides a suitable process for the treatment of a mixture of esters, acids and water resulting from the cyclohexanone production process. From the degree of separation of the mixture of esters, acids and water at atmospheric pressure and temperature of 20 ° - 110 ° C, the aqueous phase is recycled to the acid hydrolysis stage of the cyclohexanol esters and the organic phase is recycled to the acid hydrolysis stage of the cyclohexanol esters and the 10 - 20 organic phase. % by weight is sprayed onto the dewatering column. The method of the present invention improves the energy balance of cyclohexanone production and allows the use of organic acids in the acid hydrolysis step of cyclohexanol esters. 242202 i 3 4 242202

The invention relates to a process for the treatment of a mixture of esters, acids and water in a process for the production of cyclohexanone.

The by-products of cyclohexane to cyclohexanone oxidation are predominantly formed by organic dibasic acids HOOC - (CH 2) n - COOH, where n = 2 - 10, and their esters. The processing methods for these acids are described in the patent numbers PER 55 440, 63 909, 102 488. Obtaining these substances in pure form is very difficult because it is a mixture of very related substances.

Another way to process these wastes is by burning them together with alkaline wastes, where the final product is sodium carbonate. The disadvantage of this procedure is that a large amount of water is introduced into the process in previous operations, which needs to be removed before combustion. This is to distill 40-80% most often 50-70% by weight of water to bring the mixture to the desired water content below 10% by weight. The thickening distillate is returned to the acid hydrolysis process of the cyclohexanol esters and the organic precipitates a new process for treating the mixture of esters, acids and water.

The invention relates to a process for the treatment of a mixture of esters, acids and water in a process for the production of cyclohexanone after separation of cyclohexane, cyclohexanol and cyclohexanone. The mixture of esters, acids and water is fed to a separator operating at atmospheric pressure at a pressure of 0.4 - 0.9 MPa, where the aqueous and organic phases are separated at a temperature of 20 ° - 110 ° C, preferably 80 ° - 100 ° C. The aqueous phase, after separation, is recycled to the acidic hydrolysis stage of the cyclohexanol esters and the orphanic phase with a water content of 10-20% by weight is treated in a known manner by incineration. In order to economize the production of cyclohexanone, the process of treating the ester, acid and water mixture of the present invention removes the high energy intensity of current technology in the thickening mixture of esters, acids and water to a water content of less than 10% by weight prior to incineration. The advantage of this process is also the use of organic acids dissolved in the aqueous phase from the separation step to acidic hydrolysis of cyclohexanol esters.

The following example illustrates the process of the present invention. Example 100 1 of a mixture of acids, esters and water at a temperature of about 170 ° C and a pressure of 0.78 MPa from the acid hydrolysis stage of cyclohexanol esters is fed to a separator operating at atmospheric pressure, where two liquid phases are separated at 90 ° C. The organic phase in an amount of 32 l separated at the bottom of the separator, with a water content of 12% by weight, is burnt after concentration to a water content of less than 10% by weight. Of the aqueous phase obtained from separation with an acid number of 120 mg. I-1 (KOHJ and saponification number 135 mg. I-1 (KOH is recycled to the acid hydrolysis step of cyclohexanol esters).

Claims (1)

SUBJECT Process for treating a mixture of esters, acids and water resulting from the cyclohexanone production process after the distillation separation of cyclohexane, cyclohexanol and cyclohexanone at a pressure of 0.4 to 0.9 MPa and a temperature of 140 ° to 190 ° C, characterized in that the aqueous phase from the separation step The mixture in separators at atmospheric pressure at a temperature of 20 ° C to 110 ° C, preferably 80 ° C to 100 ° C, is recycled to the degree of acid hydrolysis of the cyclohexanol esters and the organic phase containing 10-20% by weight of water is injected into the dewatering elbow.