SU1594135A1 - Method of producing chlorine dioxide - Google Patents

Abstract

The invention relates to chemical technology of inorganic substances and can be used to produce chlorine dioxide in the pulp and paper industry as a bleach of cellulose, cotton, water disinfection and allows for the formation of chlorine dioxide in high yield, eliminating the emissions of the reaction mixture associated with deactivation of the catalyst. The method is carried out by reacting sodium chlorate with sodium chloride in a sulfuric acid medium in the presence of a catalyst at elevated temperature and reduced pressure. The catalyst used is nickel salts NI 2 + X, cobalt CO 2 + X, tin SN 2 + X, where X is SO 2 - CH 3COO -, CI -, NO 3, C 2 O 2 - or mixtures of cobalt and tin salts : CO / NO 3/2 + SN / CH 3COO / 2, CO SO 4 + CUCL 2, COCL 2 + SNSO 4 CO / CH 3COO / 2 + SNL in an amount of 0.05-1.0% based on sodium chlorate . The proposed method allows to obtain chlorine dioxide with a yield of 86.6-96.0% with repeated use of the catalyst. 4 tab.

Description

This invention relates to the chemical technology of inorganic substances and can be used to produce chloride in the pulp and paper industry as a bleach of cellulose, cotton, and water disinfection.

The chain of the invention is to simplify the process by eliminating the emissions of the reaction mixture associated with a decrease in the catalytic activity of the catalyst.

Example 1 o Into the flask are placed 60 ml of chlorate-chloride solution, heated to 60-80 ° C in the presence of

catalyst - cobalt salts (CoC.), taken in an amount of 0.01-1.0% by weight of sodium chlorate. 25 ml of 65% sulfuric acid are gradually added at a pressure of 200-250 mm Hg. Art. abs At the same time, air is bubbled through the reaction mixture, which removes the target product from the reactor — chlorine dioxide. The test time is 60 minutes, the temperature is 77 ° C, the ratio of sodium chlorate to sodium chloride is 1.65: 1. Example 2B The conditions of example 1 in the same reaction mixture. The remainder of test 1, without adding fresh catalyst, is carried out

sd with .4

with SP

chlorine dioxide production process by reacting fresh NaClOj paveschi with Nad. Target product removed. from the reactor by stripping it with air.

The results of the experiment are presented in Table 1.

From the data given in Table 1, it can be seen that the process without the addition of fresh catalyst proceeds in the same way as in Experiment 1 o This indicates the absence of a decrease in the catalytic activity of cobalt salts in the process of their recycling and conducting.

Example Under the conditions of examples 1.2, the process of obtaining chlorine dioxide in the presence of a catalyst — silver and manganese salts — is carried out by a known method.

The supply of catalysts is carried out separately with solutions of silver nitrate and then manganese sulphate. It is recommended that you never mix both solutions before they enter the reactor, so as not to precipitate an insoluble silver salt. Such a condition introduces certain difficulties in the technology for producing chlorine dioxide.

After the consumption of sodium chlorate and sodium chloride, the process of producing chlorine dioxide is carried out by adding a fresh batch of sodium chlorate and sodium chloride without adding fresh catalyst — silver and manganese salts.

The conditions of example 3 and the results of the experiment are shown in Table. 2,

When the reaction is repeated by introducing fresh reagents, the catalytic mixture loses its activity and the chlorine yield drops from 87–96.3 to 45.3–58, Uo

Reducing the yield of chlorine dioxide to 45% can occur during one cycle of the process. This is due to the partial deactivation of the catalyst. The addition of a freshly prepared catalyst causes a vigorous evolution of the gaseous chlorine dioxide product from the liquid reaction mixture and is accompanied by vigorous boiling up, emissions and explosions in the reactor.

The essence of the proposed method lies in the fact that upon receipt of chlorine dioxide as a catalyst, salts of nickel, cobalt and tin Sn are used,

where X is CHjCoo-, CI-; NO ;,

or mixtures thereof, taken in an amount of 0.05-1.0% in terms of sodium chlorate, which do not reduce their catalytic activity and can be recycled. In addition, a mixture of these catalysts has

Q is synergistic and causes significant when used in smaller quantities than cobalt, nickel or tin salts taken separately from each other.

f In table. 3 presents data on the yield of chlorine dioxide in the presence of the proposed catalysts and their mixtures in the concentration range of 0.01-1.0% of the amount of sodium chlorate,

 From the data given in table. 3, it can be seen that in the presence of 0.05% catalyst, the yield of chloride dioxide is minimal and is 86.1-90.0%. The maximum value of 96.4%

5, the yield of chlorine dioxide is reached when the concentration of the catalyst is 1%, in the presence of 0.75% of the catalyst, the yield of the product is 94.7%, which is slightly lower than in the presence of 1% of the catalyst. The optimal amount should be considered a catalyst concentration of 0.5-0.75%,

The board 4 shows the results of the yield of chlorine dioxide with repeated use of catalysts,

5 Thus, the proposed method allows to obtain chlorine dioxide with a yield of 86.6-96.0% with repeated use of the catalyst in the range of 0.05-1.0% in terms of

About sodium chlorate, while by a known method, the yield of dioxide, chlorine is reduced from 87.0-96.3 to 4.5.3- 58.1% with its repeated use,

5 The advantage of the proposed method in comparison with the known method is the simplification of the process for producing chlorine dioxide, since the use of the proposed catalysts allows

To exclude bursts and emissions of the reaction mixture occurring in a known way with the addition of fresh portions of catalyst, while the yield of chlorine dioxide decreases to 45%.

5 At the same time, as a catalyst in the proposed method, more affordable and cheap salts of nickel, cobalt and tin are illustrated in comparison with

0

with expensive and scarce silver salts, use in a known way.

Claims (1)

Formula isob rete n i The method of producing chlorine dioxide, which includes the interaction of sodium chlorate with sodium chlorine in a sulfuric acid medium in the presence of a catalyst at elevated temperature and reduced pressure, is distinguished by 5941356 y and so that, in order to simplify the process by eliminating the emissions of the reaction mixture, nickel, cobalt, tin tin salts are used as a catalyst, where X is SOJ-, CHjCOO-, Cl, NO,, or mixtures of cobalt and tin salts: CoClj + SnCl-i, СО (Koz) 2 + Q + 5n (СНзСОО) 2, CoS04 + SnClj ,; 0001 + t-SnSO, Co (CEESOO) g + SnCl, in an amount of 0.05-1, sodium chlorate. in terms of Silver nitrate Manganese sulphate Silver nitrate Manganese nitrous oxide Silver nitrate Manganese sulphate 77 80 1.65: 1 1.65: 1 80 1.65: 1 Table 1 table 2 60 87.0 A5,3 60 89.0 48.1 60 91.2 50.6 751.65: 1 701.65: 1 Sol experience CoCli Co (HOj) CoSO, Co (CHjCoO) j CoCi04  Snslj Snthoj) ,, SnSO: Sn (CHsCOO), SnCjO, Hicl Hi (HOj) j NiSO HKCHjCOO) .NiCjO,  SnClj Co (TO,) + Sn (CHjCOO) i CoSO, SnClt CoClj + SnS04 Co (C 5SiO) g. + RnCla 60 93.1 55.3 60 96.3 58.1 . Table 3 Note. All given catalyst concentrations fall within the range of 0.05-1%. 159413510 Table 4