DD154958A1 - METHOD FOR DRYING GASES - Google Patents

Abstract

The invention relates to a process for the drying of gases up to extremely high degrees of drying and to maintain the achieved degree of drying. The aim and the object of the invention is to achieve and maintain residual moisture content of about 10 to 8 molar proportions of water in gases or gas mixtures by forcing the formation of water from the reaction partners present in traces of oxygen and hydrogen, or hydrogen and metal oxide on a palladium contact and the water so formed is then adsorbed on alumina gel or synthetic type A 4 zeolites. Thus, the gas d. Possibilities of an undesirable reaction water formation taken u. it can be supplied extremely dry to the place of use, especially if in gases that still contain traces of H deep 2, the propagation takes place in metal oxide-free envelopes.

Description

224353-Ί-

[Method for drying gases ι

The invention relates to a method, in particular for extremely high drying and for maintaining the achieved degree of drying of gases or gas mixtures in Nachg.ang to conventional drying s method,

Field of application of the invention

The invention is applicable to all tasks for extremely high drying of gases or gas mixtures containing as minor constituents unbound hydrogen and oxygen, and to maintain the achieved high degree of drying of about "10" "molar parts of water under technical conditions.

Characteristic of the known technical solutions

Gases are dehumidified on an industrial scale essentially by sorption, by increasing the pressure, by lowering the temperature or by combining said processes. "The achievement and above all the maintenance of degrees of drying up to Eestfeuchten of about" 10 "molar proportions of water was not possible in technical practice in particular when these gases were stored in metallic envelopes.

Object of the invention

The aim of the invention is the extremely high drying and maintenance of Eestwassergehalten of ca, 10 molar proportions

for O ₂ -containing gas-containing gas mixtures, and O-bumped gas mixtures with Kp traces, and EU-containing gas mixtures, and gas mixtures with Q ₀ and EL 2 traces, each in contact with metal oxides or other catalytically active substances come",

Explanation of the essence of the invention

The object of the invention is, in recognition of the mechanisms of action which make it impossible to maintain high degrees of drying, to develop a method for eliminating their disadvantages,

It was recognized that Eestfeuchten of about 10 molar parts of water under technical conditions can only be maintained if, after conventional drying, the formation of water of reaction either by the reaction equation 2 Hp + Op - f - 2 HpO at catalysing substances or after the reversible reaction metal + HpO ^ = ^ · metal oxide + Hp is missing *

It is known that metal oxides act as a catalyst in the formation of water when Op and Hp are present in the gas mixture. Metal oxides are always (and unintentionally) present in practice (for example, electrolytically polished stainless steel still contains about 100 atomic layers of oxides), so that both by the presence of H ₂ by reduction of the metal oxides and in the presence of Op and H ₂ in the trace range by catalytic action of the metal oxides water arises. However, many gases or gas mixtures contain EL and O ₂

in traces; EL-containing gases or "gas mixtures contain O ₂ in traces and 0 ₂ -containing gases or", gas mixtures contain H ₂ in traces ·

According to the _e o g, reaction equations may at full implementation of this lower concentration reactant to HPO and maintaining a residual water content of for example, about 10 molar proportions in the gas of the impurity ·

8 KL not larger than 10 parts by mole

and on ... O ₂ not larger than 5 β 10 'molten ante ile

These mentioned limits for Op and EU traces in the gas are usually far exceeded in practice.

The object of the achievement and Aufreenterhaltung of Eest water contents with about 10 molar proportions in H ₂ -containing gas mixtures with O ₂ ~ tracks, or Op-containing gas mixtures with Hp traces, or gas mixtures with O ₂ - and EL traces, respectively come into contact with metal oxides, according to the invention is achieved in that before the use of the gas as extremely dried, the formation of water of reaction in a container equipped with palladium contact reactor is forced, the reaction water thus formed is then adsorptively bound to adsorbents and the forwarding and storage Hp- containing gases in metal oxide-free coatings *

embodiment

With reference to an embodiment of a technical utility of the invention will be shown «. The liquid cup nitrogen from the pressure column of an air separation plant, which would theoretically have a residual moisture, which is well below 10 """molar parts of water due to the prevailing pressure and the temperature, shows according to measurements - especially in the phase del ¹ startup

5 of Np-line system moisture contents of about 10 to 10 molar portions of water even after intensive drying of the piping network. This moisture content is due to the desorption of water from the pipe walls into the gas. But even after several years of operation, a moisture

halt of 10 "" mole fractions HpO not maintained in the network, since in this reaction water formation takes place, which is still favored at elevated pressures. In addition, Hp and Op, which are still present in traces in the ITp, react with the metal oxides of the conduction system. Furthermore, Hp can pass into the nitrogen gas by diffusion from the inside of metal walls and subsequent desorption and increase the moisture content in the gas by reaction with O ₂ and / or metal oxides. «

2 4 353

Therefore, according to the invention immediately after evaporation and heating of the liquid nitrogen and in longer networks, if necessary, before the point of consumption of the extreme

dry nitrogen (10 * "molar proportions HpO) the same over a special catalyst, preferably palladium contact, gefüllten.Reaktor passed on which the targeted implementation of the present in the trace range Hp and Op impurities to water in such a way that up to the consumer no unwanted Subsequently, the water of reaction formed by means of special adsorbents, preferably those of the type Aluminiumoxidgel or synthetic zeolites of the type 4 A, under extreme conditions, d ' _oo under temperatures <400 ⁰ C, for about 48 hours long and permanent Rinsing with dry Hp to regenerate are removed from the gas «

Claims (1)

- 5 - 224353 invention claim Process for the extreme drying and maintenance of the residual moisture of dried gases or gas mixtures containing Hp and in traces Op or in traces of EL ^{un (} ^ Op »or Oo and in traces H, and with metal oxides and / or catalytically active substances come into contact, characterized in that the reaction of Hp and O ₂ to water is almost completely completely enforced on a palladium contact by a present in lower concentration reactants is almost completely consumed, so that in subsequent management or storage systems from a reaction water formation the primary contained in the gas Ho and Op traces can not be practically done, and that the reaction water formed is then bound by adsorption on adsorbents of the type alumina gel or to synthetic zeolites type A 4- or a combination of both, and that the achieved degree of drying in still ELj-containing gases upright old is, by the storage or, port line of the same takes place in metal oxide-free sheaths.