DE919710C - Process for the production of hydrogen peroxide - Google Patents

Description

Process for the production of hydrogen peroxide It is known Hydrogen peroxide is split off by vacuum distillation of H2 02 in the heat Create connections in falling pipes. This can be done during the distillation resulting hydrogen peroxide vapors at the lower end (direct current), at the upper end At the end (countercurrent) or at the top and bottom at the same time. One arrives in this way to vapors containing only 2 to 3 per cent. hydrogen peroxide besides water contain.

Investigations of the evaporation process along the distillation pipe have shown that persulfate solutions initially give off mainly water vapor, before the progress of the saponification process significant quantities of hydrogen peroxide are formed.

This fact can be exploited in valuable ways to simplify matters Ways to get to highly concentrated hydrogen peroxide vapors. If you use namely a distillation tube, from which the vapors are removed from above and below can, the separate separation of the succeeds in the first phase of the distillation evaporating water by the fact that the pressure maximum along the axis of the distillation tube Relocated to a place where practically no hydrogen peroxide has distilled off or at least so little arises that the multitude can be discarded. In such a System must necessarily have pure water vapor upwards and H202 vapors downstream pour down.

For example, the essence of the present invention can best be understood represent on the basis of the drawing.

Flows through the distillation pipe i, which is heated from the outside from top to bottom in thinner Layer z. B. a solution of ammonium persulfate. If suction is now only performed at 6, all vapors will condense together. The concentration of hydrogen peroxide is about 2.5%. The residue solution expires at 3 and is z. B. in another tube .I one of the known 'aftertreatments subject, the vapors of which can also be pumped out at 6. The pressure maximum In this process, inside the tube i lies at the upper end 2.

For example, from the point marked X downwards the actual release of hydrogen peroxide takes place. Distilled above X just wetting out of the solution.

If a vacuum is now applied to 5 in addition to 6, the maximum pressure in the pipe moves from 2 downwards, for example to about point Y. As a result, all vapors above Y flow upwards, all vapors below Y downwards. Pure water vapor will flow out at 5, whereby the hydrogen superoxide vapors removed at 6 experience a corresponding increase in concentration.

The position of the pressure maximum Y can be chosen arbitrarily. Will the vacuum at 5 increased. so Y descends and approaches X. By further lowering the pressure at 5, Y can be moved below X. But then, even at 5, there are hydrogen peroxide vapors sucked off, which is to be avoided in the context of the invention.

The position of the point X depends, of course, essentially on the composition the solution and the temperature distribution in the pipe. X is e.g. B. to the deeper, the more dilute the solution used for distillation is.

So one is through preliminary tests for each distillation system at given pressure 6 must set the level of vacuum at 5. That’s the point Y to be placed so far above X that within the technically avoidable fluctuations the pressure, the flow rates and the heating no significant amounts of hydrogen peroxide flow upwards. The measure takes place in a very simple manner by regulating the pressure at the ends of the distillation tube.

Those pumped out at 6 when performing the present method Hydrogen peroxide vapors have a concentration that arbitrarily meets the requirements the fractionation plant bz «-. can be adapted to production. For example, you can can be set to 6 or io%.

A process is already known, its external characteristics partly agree with the present proceedings, in that the Distillation vapors can be taken from both pipe ends. But with this way of working «-Earth both above and below hydrogen peroxide vapors sucked off and therefore also mutually derived and condensed accordingly. The possibility of a separate Obtaining the distillates was not even considered there because the effect of the present invention has not been recognized.

In the following an embodiment is given in which the pressure maximum lies along the pipe axis in the lower half of the pipe and at the lower end of the pipe an approximately 10% hydrogen peroxide can be removed.

Embodiment 6 l of a solution containing 230 g / l ammonium persulphate and zoo g / l sulfuric acid flow from top to bottom every hour through a vertical pipe 1 in length and 30,111 m inside width; if necessary, the solution can be wholly or partially pre-saponified to caric acid beforehand.

The pipe is filled with steam from the outside 3 ,; atü heated. Will the Vapors at a vacuum of 3o Torr only sucked off at the lower end of the tube, so about 3% hydrogen peroxide is obtained. But if you put it at the same time at the top At the end of the pipe a vacuum of 31 Torr can be reached, a hydrogen peroxide of approx io% are withdrawn, while at the upper end of the pipe water vapor with less than o, o2% H20 escapes. The pressure maximum along the pipe axis is approximately in the lower position Third of the pipe, with post-treatment of the residue taking place in the same system obtained with steam in an amount of 10% of the original solution weight a hydrogen peroxide of about 8.5'10 is obtained with a 95% yield.

Claims (1)

PATENTANSFRUCII: Process for the production of hydrogen peroxide by vacuum distillation of solutions of persulfuric acid and caroic acid or their Salts in the falling pipe with suction of the vapors at both pipe ends, characterized in that one adjusts the position of the pressure maximum along the axis of the distillation tube so, that practically only pure water vapor is sucked off at the upper end, while at the same time hydrogen peroxide vapors enriched in a known manner at the lower end of the pipe removed, discharged separately and optionally further processed in a known manner will. Cited publications: German Patent No. 687 292; Swiss U.S. Patent No. 174,343; U.S. Patent No. 2,091,218; 11Z a c h u, »Das Hydrogen peroxide, 1937 pp. 168/169.