DE2233846C3 - Method and device for the enrichment of deuterium in a bithermal process - Google Patents

Description

Exchange stage exiting gas-vapor mixture serves at least one condenser and through at least an evaporator for evaporating the liquid emerging from the lowest distillation device.

It should be noted that, in contrast, the distillation devices used in accordance with the invention are much less expensive facilities at exchange levels. It is well known that the kinetics between a liquid exchange medium and a gaseous exchange medium is significantly smaller than the kinetics of a liquid phase with its own vapor. Therefore are in the exchange stages larger residence times are required, resulting in larger exchange volumes in contrast to distillation devices entails.

The method and the device of the invention are used for bithermal systems in which by Isotope exchange between one of hydrogen or hydrogen as a compound or mixture component containing feed stream with the liquid phase, the latter enriched in deuterium, then in a cold column further enriched in deuterium through isotope exchange with the gaseous phase, and finally in a warm column by isotope exchange with the gaseous phase of deuterium is depleted. The method according to the invention is carried out such that the liquid Phase after deuterium depletion in the warm column returned to the top of the extraction column and that the column emerging from the head of the cold column is depleted of deuterium gaseous phase is conveyed into the bottom of the warm column. Having dealt with herein in each When the separation stages have been enriched in deuterium, it is returned to the bottom of the cold column. In the distillation devices arranged between the individual separation stages is that of the gaseous Phase entrained vapor - which comes from the liquid phase - by deuterium exchange with the circulating liquid to at least approximately the same deuterium concentration enriched in the liquid phase of the next upper separation stage.

There are various designs for bithermal systems. So there are z. B. Cases in which there is no separate extraction column. It can therefore also be useful, in addition to the so-called warm tower, also the so-called cold tower Train tower in the manner according to the invention.

Further features of the invention emerge with reference to that shown in the drawing and in the following explained flow charts.

The system shown is used to carry out a bithermal process and is essential Plant parts an extraction column 1, a cold exchange column 2 and a warm exchange column 3, which is formed in the manner according to the invention.

The operation of this bithermal system takes place in the following way.

In the extraction column 1 is a feed stream consisting of hydrogen with z. B. more natural Deuterium concentration initiated through line 4. Depleted in deuterium, it leaves the column at its upper end through the line 5.

In the upper end of the column 1 is through line 6 after cooling to the operating temperature in Cooler 7 the liquid, deuterium-depleted phase z. B. methylamine initiated. In column 1 he there follows a transfer of deuterium from the feed stream 4 to the liquid phase, so that diesi Column 1 at the lower end in enriched to stand leaves. It is through line 8 in the Kalti Column 2 fed. Here, through exchange with the countercurrent gaseous phase, ζ. Β Hydrogen, the liquid phase continues to Deuteriun

ίο enriched and after heating in countercurrent heat exchanger 10 and in the heater 11 fed into the warm column 3 through line 9.

In this column the liquid phase is in a individual separation stages in countercurrent to the gaseous phase depleted in deuterium, as in after standing point will be explained in detail, unc finally through line 6 via the heat exchanger 10 and cooler 7 are conveyed back into the extraction column 1 with the aid of the pump 12.

The column 3 is formed in the inventive manner and consists essentially of individual plates 13a to 13 d and distillation column !! 14 «to 14r. All elements can be arranged, for example, in a closed container, as is indicated schematically by the dash-dotted line. The separation stages, in which a deuterium exchange between the liquid and the gaseous phase takes place, can in a known manner with overflows and to bring about an intimate mixing of the two phases with mixing devices, e.g. B. ejectors and liquid gas separators and if necessary contain a catalyst. The distillation columns, in which a deuterium exchange between the vapor of the liquid phase and a liquid of the same type takes place, can, for. B. be designed as bubble or sieve tray columns. The column 3 is operated in the following manner.

After heating in a heat exchanger 16 to the operating temperature of the column 3, a gas-vapor mixture is introduced into the lowest separation stage 13 d through a line IS.

This mixture consists of the deuterium-depleted gaseous phase, which consists of the withdrawn the upper end of the column 2 through line 17 with the aid of the fan 18 and to the bottom of the Column 3 is promoted, and on the other hand from vapor of the liquid, which from the lowest Distillation column 14 c removed, and through line 19 with the aid of the pump 20 in the evaporator 21 is promoted and evaporated there by heat exchange. Residual components of non-evaporated Liquids are evaporated in the heat exchanger 16. This gas-vapor mixture depleted in deuterium occurs in the separation stage 13 ti with the liquid flowing down from the separation stage 13 c Phase in contact, with deuterium being transferred from the liquid phase to the gaseous phase. Of the The vapor fraction of the gas-vapor mixture has the same deuterium concentration as the liquid phase at this stage. The gas-vapor mixture is then introduced into the distillation column 14 c and with liquid flowing downwards in the column, in the exemplary embodiment methylamine brought, with deuterium being transferred from the liquid to the vapor (which is the gaseous phase in this exchange process auasi as "ballast"

and only takes part in the exchange to an insignificant extent). The steam is at least almost on the Deuterium concentration of the liquid phase in the next upper separation stage 13 c enriched. Since the Isotope exchange between vapor and liquid of the same type takes place quickly, columns can be simpler Type of construction, d. H. can be used without additional mixing devices.

The gas-steam mixture is then introduced into the separation stage 13 c, in which the same process takes place as in the separation stage 13 d. Of course, the deuterium concentration of the liquid and the gaseous phase are different from those of d in the separation stage. 13

Would c without the arrangement of the distillation column 14 the d emerging from the separation step 13 steam having the same concentration as the liquid phase in the separation stage 13ö ". This would mean that the deuterium concentration of the liquid phase in the separation stage 13 c by a kind of short-circuit effect of lowered and this would worsen the separation effect in the separation stage.

The deuterium exchange between the liquid and the gaseous phase and the vapor of the liquid phase and liquid of the same type takes place in the same way in the separation stages 13b, 13a and Ub, Ua.

From the upper end of the separation stage 13 a, the deuterium-enriched gas-steam mixture, in the exemplary embodiment hydrogen and methylamine steam, is introduced through a line 22 into the heat exchanger 23 and the steam is condensed out here. The condensate reaches the uppermost distillation column 14 a via line 24.

The gaseous phase is passed through line 25 after the condensation still remaining in the gas Steam residues are fed into the lower part of the cold column 2 in an aftercooler 26.

The condensate from the aftercooler 26 is over Line 27 mixed with the condensate coming from the heat exchanger 23.

In the exemplary embodiment, the condenser 23 and the evaporator 21 are a combined unit designed in such a way that an indirect heat exchange takes place between the two. This is in thermodynamic Relationship extremely beneficial.

At the point of greatest deuterium enrichment, for example at points A _1, a subset of the deuterium-enriched liquid phase and / or at point B ₁ a subset of the deuterium-enriched gaseous phase can be withdrawn from the system and used as a feed stream into a system (not shown) Execution to a further concentration and extraction of heavy water can be initiated.

The partial quantities depleted of deuterium in the plant are returned to the line 9 and 25 at a point A ₂ or B _{2, respectively.}

Numerical examples

To demonstrate the economic viability of the invention, three numerical examples (Ia, Ib; II a, Hb; HI a, IIIb) given below.

In Examples I a, Ib, Ha are each for one Plant designed according to the invention according to the flow diagram and in Examples lib, HIa, IIIb, respectively the calculated reference values are given for a system that has been customary up to now, with the same in each case Conditions in terms of system pressure, temperature and the same deuterium concentration for further processing were given by heavy water. In Table I, the names of the Numerical examples of registered reference values are explained.

The economic viability of the invention is clearly demonstrated by the numerical examples. One A comparison of the numerical examples shows Taao belleil.

Table I.

Explanation of the in the numerical examples
inserted designations

ρ - pressure

t = temperature

κ = exchange or separation factor

x = D ₂ concentration in the liquid phase

y = D ₂ concentration in the gas phase

IW = 144-10 " peuterium atoms
Hydrogen atoms

= Number of moles of circulating gas flow

n _fl = number of moles of the circulating liquid (based on the H ₂ molecules of the liquid which D _{2 are} exchangeable)

ζ = number of exchange levels

in 2

Table II

Operating Operating Rafr iplic number temperature temperature DClI ICUj
pressure the end Counting the cold one the warm exchange examples exchange exchange step ζ column t column / P [bar] ( ⁰ C) ( ⁰ C) 300 38 Yes -23 50 300 56 Ib -23 50 300 32 Ha -23 97 300 58 Man -23 97 200 32 III a -23 97 200 129 IIIb -23 97

In addition 7 sheets of drawings

Claims (2)

1 2 enrichment with fewer separation stages and a ge patent claims: lower energy requirement. With the known deuterium exchange process 1. Process for the enrichment of deuterium that work according to the countercurrent principle, where ζ. Β in a bithermal process in which a 5 water as the liquid phase and hydrogen sulfide as Hydrogen as a connecting component enthal gaseous phase or water or methylamine and Tending liquid phase in countercurrent to a gaseous hydrogen in countercurrent and from hydrogen or hydrogen as a connection in the separation stages are brought into contact, isl or mixture component containing gas conveying it inevitably that from the downward flowing In the case of a liquid, part of it evaporates and of the gaseous one lower temperature Deuterium from the gene, upward-flowing phase to the next gaseous phase Phase is entrained on the liquid phase and at the upper separation stage. Since this from dei • a higher temperature deuterium from the liquid vapor has the same concentrated liquid phase to the gaseous phase transfer as the liquid, changes the carry, characterized by 15 deuterium concentration of the liquid next to that of the exchange from the liquid upper separating stage . This means that the separation effect of the vapor between the exchange and exchange column is worse than if there were no vapor stages in the distillation device with the one that causes the isotopic liquid of the vapor to be backmixed in deuterium exchange from one stage to the other,
is brought, with the liquid, which flows through the 20 multi-stage distillation devices required for this reason, circulates in an exchange column of the hitherto customary design and from which the uppermost circumstances a considerable number of separation stages, by vapor-gas leaving the exchange stage -Mixture as the achievable separation effect, ie the enrichment condensate is obtained, then the in series an- grad to achieve. ordered distillation devices from above 25 This shows that the previously usual Vernach flows through below, after leaving the drive, the more uneconomical, the higher the lowest distillation device evaporates, and operating temperature of the exchange column is. In solmit of the small cases fed to the lowest exchange stage can of course phase out parts of the liquid phase is united. vapor and from the gaseous phase to the upper 2. Device for carrying out the process 3 ° ren separation stages are also transported. The Verrens according to claim 1, characterized by the ratio of the amount of steam to the amount of gas depends on this several exchange levels arranged in series decreases from the total pressure in the system and increases with increasing (13a to 13d), through the exchange of temperature not only linear but with a rank arranged distillation devices to higher potency. (14a to 14c), at least one capacitor (23, 35) The invention has set itself the task of the 26), as well as at least one evaporator (21) to change the concentration due to the pre-evaporation the evaporation of liquid from the lowest distillation described above device (14 c) escaping liquid. arise, from separation stage to separation stage at least approximately equalize, so that the same separating 40 effect can be achieved with a significantly lower number of separation stages. This object is achieved according to the invention solves that the exchange from the liquid Phase resulting vapor between exchange stages 45 in distillation devices with the liquid of the Vapor is brought into deuterium exchange, the liquid soft the distillation device The invention relates to a method for enrichment flows through which the uppermost exchange of deuterium in a bithermal process, in a steam-gas mixture leaving the stage as a condenser a hydrogen as a compound composite is obtained, the series-arranged distillation units containing liquid phase flows through devices in countercurrent from top to bottom, according to (Do one made of hydrogen or hydrogen as a connection outlet from the lowest distillation device «Lung or mixture component containing gas vaporized, and with that of the lowest exchange stage shaped phase is performed and is combined in the exchange at the supplied phase. The liquid will * In a lower temperature deuterium from the gas 55 thus circulated. L-shaped phase to the liquid phase and a device for carrying out this process higher temperature deuterium from liquid driving is characterized by several in series Phase is transferred to the gaseous phase, and arranged exchange stages, which from top to Oil phase enriched with deuterium to the bottom directly from the liquid phase and from below use of heavy water. The invention 60 upwards from the gaseous phase and from Application also relates to a device for performing the liquid phase flowing through the resulting vapor initiation of the procedure. and through between the exchange levels The invention has a method and an arranged distillation apparatus, which in the Strö apparatus for deuterium enrichment to the goal of the gaseous phase and the from the sets, which are a vapor produced compared to the previously usual liquefied phase, whereby drive far less effort in terms of prostitutes - these distillation devices also in Strösionierung the device enables, in particular, a liquid flow path are arranged to their by achieving the desired generation of deuterium from the vapor of the uppermost