SU1039176A1 - Method of cleaning mother liquor of hexamethylenetetramine - Google Patents

Abstract

A METHOD FOR CLEANING THE HEXAMETHYLENETTERAMINE TREATMENT, obtained by reacting formaldehyde and ammonia, characterized in that, in order to increase the purity of the target product, the mother liquor is passed through an electrodialyzer with selective ion-exchange membranes under a heart rate of 18-283% and 100% of them, using a cell and a heart rate of 18–283, using a cell and a cell under the pressure of 18–283, and then using a selective ionite membrane under the pressure lines of 18–283 and under the pressure lines and 18 and 183% of them, and then, asphidical membranes under the pressure of 18–183, the flow of hearths is passed through the electrodialyzer with the selective ion-exchanger membranes under the effect of 18–183 –– –––––––––––––––––––––––––––– mA g

Description

SAE SO

one

9 11 The invention relates to the field of producing hexamethylenetetramine (PTA), in particular to a new method of purifying its mother liquor, FMTA is widely used in the production of plastics explosive; substances and other industries. A known method of purification of the mother solution of hexamethylenetetramine, obtained as a result of the interaction of formaldehyde and ammonia, to which purifying agents are added to avoid the accumulation of impurities. The disadvantage of this method is the accumulation of waste and the problem of their elimination. The closest to the described method is the purification of the uterine solution of hexamethylenetetramine, which is agglomerated as a result of the interaction of the ferromaldehyde and ammonia, by treatment of the circulating mother liquor with a successively activated light of OSh grade AU coal and granulated carbon of the SKG grade. Characteristics of the obtained target product are presented in the table. The disadvantages of this method include: the cumbersome instrumentation of the cleaning process of the circulating fluid; the accumulation of a large number of Lt moves (activated carbon consumption 100 kg / m); the cleaning efficiency of the mother liquor is insufficient and, as a consequence, the poor quality of the hexamethylenetetramine obtained (a permanganate number does not exceed 25 min). The purpose of the described invention is to increase the purity of the target product. The objective is achieved by a new method of purifying the mother solution of hexamethylenetetramine, which is contained in TOMJ, that the mother liquor transmits an even: electrodialyzer with selective ion exchange membranes at a constant electric voltage of 18-28 V and a current load of 127-190 mA . As a rule, MK-40 and MA-40 membranes are used as selective ion-exchange membranes. The positive effect of the described method is an increase in the rate of the mother solution of hexamethylenetetramine, namely, a decrease in the content of amine impurities by 3.2-4 times and complete purification from oxidizing impurities. The indicator - the permanganate number of the HGA stock solution according to the described method is 170-228 s, while in the known method the permanganate number of the HMHA does not exceed 90 s. Waste is practically absent. The reduction of impurities in the mother liquor leads to an increase in the quality of the obtained FIFA. Example 1. In a 700 ml beaker with a capacity of 700 ml, 170 ml of ammonia water and 270 ml of formalin are maintained, while maintaining the reaction temperature of 20 ° C. The reaction mixture is transferred to a distillation flask and evaporated in the following mode: liquid temperature 75-78 s. phases; : /. . ; steam temperature C; phases. / ...; -. . vacuum1 ": 300-350 mmr. St. When a suspension containing about 30Z of a solid phase (HMHA crystals) is formed in the flask, the distillation process is stopped. Hexamethylen-tetramine crystals in an amount of 30 g are filtered from the mother liquor on a vacuum funnel. The resulting mother liquor in an amount of 100 ml is fed to an electrodialysis unit with selective ionization: aymy membranes. A current load on the electrodialysis unit is established: a torus is 160 mA and a multiple circulation is carried out under a constant voltage of 23V. The purified HMGA mother liquor is sent to the urotropin synthesis reactor. The characteristics of the stock solution are given in the table. -. , -. Pr and M e p 2. The mother solution of HMTA, obtained under the conditions of Example 1, is sent to multiple circuits through an electrodialyzer at a Demand voltage of 18V and a current load of 127 mA. The purified STA uterine asthma is sent to peaiKTop intez. The characteristics of uterine solution are shown in the table. EXAMPLE 3. The MTA stock solution obtained under the conditions of Example 1 is directed to multiple circulation through the electrodialysation at a constant voltage of 28V and current.

load 190 mA. The purified mother liquor is directed to the synthesis of HMTA.

Characterization of the stock solution is given in the table.

Amine impurities content in the uterine solution, calculated as U% 3.3. Retention of oxidizing impurities in terms of HCET,% 10.2 Lack of Per-ananthone number of the mother liquor, с35220 Permanate number. Hexamel-galentetramine, 1840 min. 170228. 3742

Claims (1)

METHOD FOR CLEANING THE HEXAMETHYLENETETRAMIN UTERINE SOLUTION obtained as a result of the interaction of formaldehyde and ammonia, characterized in that, in order to increase the purity of the target product, the mother liquor is passed through an electrodialyzer with selective ion exchange membranes at a constant electric voltage of 18-28 V and a current load of 127-190 mA. > 10391