CS261545B1 - Process for desorption of gases from liquid solutions - Google Patents

Abstract

The solution deals with the separation of gases from liquid solutions. Dissolved gases in liquid solvents in various chemical technology processes are removed by differential rectification at an infinite reflux ratio with a stream of inert gas. The separation effect is better than in the methods used so far and the liquid phase losses are also reduced.

Description

The present invention deals with ^one of desofpcioiLjplynOjY> L liquid solutions. In rfti & It is a very common case that the liquid media used in the gas component absorb part of the gas component.

Another reason for the presence of soluble gases is their release by chemical means in technological processes. In most cases, the presence of soluble gases in liquids is an undesirable phenomenon for several reasons. For example, there is a deterioration in the quality of the solvents used, respectively. the use of liquids in technological processes is impossible due to chemical side reactions, the dissolved gaseous components cause mechanical fouling of the apparatus after its dropping in the form of insoluble compounds, etc.

In practice, desorption of the gases is effected by the flow of another gas, distillation or rectification, respectively. using vacuum. In the case of volatile liquids, or at low dissolved gas concentrations, due to the relatively high solvent losses, these methods are not the most appropriate for economic reasons. The solvent losses in these cases, depending on the properties of the mixture and the desorption level required, may be 5 to 15%.

Another drawback is that the separation effect achieved is not always proportional to the operational cost of desorption.

The present invention is based on the desorption of gases based on differential rectification of the solution at an infinite reflux ratio with an inert stream (e.g., air or nitrogen), i.e. the distillate is not removed. their equilibrium composition in the vapor phase is in the liquid phase.

The desorption solvent of the present invention is substantially free of solvent; gases. Due to the large concentration of dissolved gas in the vapor phase at the top of the rectification column, the consumption of Inert is low and solvent losses are also low compared to other methods.

EXAMPLE

Methanol is used as a solvent in the process of producing N-phenyl-isopropyl-p-phenyldiamine (Ainitioxidand CD]. The recovered methanol from the production contained 0.5% w / w ammonia by chemical reaction. After 70 minutes, methanol contained 0.0-3% ammonia, losses on methanol were 5%, and by desorption according to the invention, the ammonia concentration decreased to 0.024% after 40 minutes.

Example 2

In the second case, methanol contained 0.44 percent ammonia. Desorption was performed by differential rectification at a reflux ratio of R = 16 for 60 min. Upon completion, the methanol contained 0.14% ammonia. The amount of distillate collected was 7.5% of the flood level with an ammonia content of 2.8 percent.

Desorption according to the invention after 60 minutes resulted in a reduction of ammonia to 0.02 percent. The observed losses on methanol were 1.35%.

Claims (1)

OBJECT OF THE TREATMENT OF THE GAS FROM THE LIQUID SOLUTIONS, characterized in that the gas from the liquid is removed by a differential rectification of the invention by infinite reflux ratio of inert gas flow.