DE1041929B - Process for the preparation of hydroxylamine sulfate solution by stepwise hydrolysis of solutions of hydroxylamine disulfo-acidic salts - Google Patents

Description

It is known that the alkali or ammonium salts of hydroxylamine disulfonic acid, as described in aqueous solution according to the Raschig method in the reaction of a nitrite with a bisulfite Discharge of sulfur dioxide are readily available by gradual hydrolysis over the subject Let the salt of hydroxylamine monosulfonic acid be converted into hydroxylamine sulfate. The process "goes under Heat development in front of you according to the following equations:

HO-N (SO ₃ NH ₄ ) ₂ -iH ₂ O

= HO-NH-SO ₈ NH ₄ + NH ₄ HSO ₄
2HO • NH • SO ₃ NH ₄ + 2H ₂ O

= (NH ₂ OH) ₂ -H ₂ SO ₄ + (NHJ ₂ SO ₄ .

The hydrolysis of the first sulfonic acid group is a very rapid reaction that occurs at a temperature of 100 ° C is completed in a few seconds. The information in German patent specification 814144 relate essentially to this first stage of hydrolysis. The rate of hydrolysis of the monosulfonate to hydroxylamine sulfate, however, is significantly lower and needs at 100 ° C several hours.

In the "technology", the hydrolysis was either accomplished by long standing at room temperature or by heating to 95 to 100 ° C. In the first In this case, very large reaction volumes are required because of the low rate of hydrolysis, and a degree of hydrolysis of only 75% is achieved even after several days. In the second case a degree of hydrolysis of 85 to 90% is achieved; but it must have energy for heating and cooling are additionally expended.

It has now been found that the preparation of hydroxylamine sulfate solutions is particularly expedient and can be carried out in a simple manner if the hydrolysis of the hydroxylamine disulfonic acids Salts released heat is used to the reaction by means of heat exchange without to keep further energy supply in motion that initially a partial hydrolysis of the cold supplied Starting solution for hydroxylamine monosulfonate in one with the finished hot hydroxylamine sulfate solution applied heat exchanger made and then the hydrolysis of the monosulfonate to hydroxylamine sulfate in a container is carried out, which is to be chosen so large that the residence time of the solution in it is sufficient to the to ensure slow hydrolysis of the second sulfonic acid group.

To clarify the idea of the invention, the sequence of the process is illustrated using the drawing explained: From the storage container 1 is with the

Method of manufacture

of hydroxylamine sulfate solution

by gradual hydrolysis

of solutions hydroxylamine disulfo-

acid salts

Applicant:

VEB Leuna-Werke »Walter Ulbricht«,
Leuna (Kr.Merseburg)

Dr. Alfred Schäffler, Dipl.-Ing. Friedrich Bach

and Dr. Gerhard Meier, Leuna (Kr.Merseburg),

have been named as inventors

Porcelain pump 2 running an aqueous solution of a hydroxylamine disulfonic acid salt over the heat exchanger 3 and the steam-heated heater 4 in the lined hydrolysis tank 5 printed. The throughput can be controlled with the valve 6 via a handle. From the container 5 The aushvdrolysierte solution flows continuously via a siphon back into the exchanger 3, from where it after the lined collecting tank 7 is passed. It is useful to have the container 5 so high make sure that the hydrostatic pressure is sufficient for the automatic delivery of the solution to container 7. Since sulfuric acid is released during the hydrolysis of the hydroxylamine disulfonate, the apparatus must made of acid-proof material. All of your cables are therefore made of porcelain or, where the temperatures permit, made of polyvinyl chloride. The heat exchanger 3, the The heater 4 and the cooler 8 are made from graphite plates impregnated with plastic resin and glued. Containers 1, 5 and 7 are made of acid-proof brick.

When the process is carried out, the heat of reaction released is used once to keep initiated hydrolysis going without additional energy supply. For this purpose must the heat exchanger 3 be dimensioned so that the amount of heat carried by the hot, from the container 5 outflowing hydroxylamine sulfate solution as far as possible to the counterflow, from container 1 coming cold, hydroxylamine disulfonic acid solution can be dispensed. Here the hydroxyl

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amine disulfonate already completely hydrolyzed to monosulfonate. The heat exchanger thus serves at the same time as a reaction vessel for the first stage the hydrolysis to monosulfonate.

The resulting heat of reaction contributes to this. to keep the entire process going without additional energy input. The heater 4 is only heated with steam until the solution flowing out of the container 5 is sufficiently heated to initiate the reaction in the heat exchanger 3, this has happened. then the further supply of steam to 4 is turned off and the solution L by ^T mstellung of the valves 9 and 10 are directed directly into the container 5 through a handling. The cooler 8 indicated in the drawing is only required for turning off the apparatus in order to be able to cool down the contents of the container when it is drained.

The hydroxylamine sulfate solution prepared by the process can be used directly for the oximation of ketones or for the production of solid hydroxylamine sulfate.

example

3300 1 of a solution containing 173 to 187 g of hydroxyl amine disulphonic acid ammonium per liter, are pressed into the heat exchanger at a temperature of 1 to 5 ° C and through the counterflow hot hydroxylamine sulfate solution heated to 90 to 95 ° C. This is what happens at this temperature Reaction mixture into the hydrolysis tank, in which the heat released causes a further increase in temperature takes place at 100 to 104 ° C. The residence time in the hydrolysis tank is 4 hours. The hot, fully hydrolyzed solution is returned to the heat exchanger and then through the cold starting product flowing in the opposite direction is cooled to 20 to 25 ° C. The resulting solution contains 125 up to 130 g of hydroxylamine sulfate per liter.

Claims (1)

Claim: Process for the preparation of hydroxylamine sulfate solution by stepwise hydrolysis of Solutions of hydroxylamine disulphonic acid salts, characterized in that initially a partial Hydrolysis of the starting solution supplied cold to hydroxylamine monosulfonate in one with the finished hot hydroxylamine sulfate solution acted upon heat exchanger and then the Hydrolysis of the monosulfonate to hydroxylamine sulfate is carried out at about 100 ° C. Considered publications:
German patents No. 814 144, 878 199,
884 357; K i e s e r, manual of chemical-technical apparatus. 1939, Vol. Ill, p. 1283. 1 sheet of drawings © 809 660/238 10.5 &