CS249909B1 - A method of regenerating a neutralizing solution in the manufacture of butyl acetate - Google Patents

Abstract

The regeneration of the neutralization solution of sodium carbonate in the production of butyl acetate is carried out with sodium hydroxide as many times as necessary until the concentration of sodium acetate in it increases to a value enabling its processing into crystalline sodium acetate.

Description

The present invention relates to a process for regenerating a neutralizing solution in the manufacture of butyl acetate, which allows its further use in the production of sodium acetate.

Since strong alkalis cause hydrolysis of butyl acetate, less than a fifteen percent solution of sodium carbonate in water is used to neutralize acetic acid contained in crude butyl acetate. During the neutralization, only its half is used, as shown by the equation NU2CO3 + CH3COOH = NaHCO3 + CH3COONa.

For further neutralization, the bicarbonate would decompose and the resulting carbon dioxide would prevent a continuous counter-movement of the aqueous and butyl acetate phases by the neutralization column. So far, the neutralized solution thus drained is discharged into the chemical drain after removal of soluble butyl acetate. A limiting factor for its further use is the low concentration of the constituents contained.

The principle of the process of regeneration of the neutralizing solution in the production of butyl acetate consists in the possibility of converting sodium bicarbonate into normal sodium carbonate using sodium hydroxide as shown in the equation.

NaHCO 3 + NaOH = Na 2 CO 3 + H 2 O. This makes it possible to reuse it in production. Neutralization of butyl acetate takes place at a temperature of 20 to 25 ° C, where the solubility of sodium acetate allows the regeneration of the neutralization solution to be carried out at least four times at a 5% initial concentration of sodium carbonate. Consequently, the concentration of sodium acetate in the neutralization solution is increased to a value which allows it to be used advantageously for the production of crystalline sodium acetate.

The regeneration of the neutralizing solution can be carried out for a long time if a suitable separation of sodium acetate is obtained, which at a higher concentration falls out of the solution in the form of crystals. To regenerate the neutralizing solution, it is preferable to use a maximum concentration of sodium hydroxide to avoid a large increase in its volume.

In practice, the regeneration is carried out by adding sodium hydroxide to the spent neutralization solution in an amount equivalent to that of sodium bicarbonate, as determined, for example, by titration using the dl-Winkler method.

The main advantages of the proposed regeneration are the amount of further utilization of the worn solution, including trapped acetic acid, to produce crystalline sodium acetate and reduce energy consumption to avoid dissolved butyl acetate. In the volume of 2.5 m3 of neutralizing solution to be recovered, the content of 297.5 kg of bicarbonate was analytically determined. To this volume, 142 kg of sodium hydroxide, granulated, of sodium hydroxide are added sequentially while being pressurized with air. After the solution has cooled, it is ready for further use in production.

Claims (1)

Process for regenerating a neutralizing solution in the production of butyl acetate, characterized in that it is carried out with sodium hydroxide until the concentration of sodium acetate is increased to a value allowing its further use in the production of crystalline sodium acetate.