US1658631A - Process of obtaining argon - Google Patents

Description

W. DANNENBAUM PROCESS OF OBTAINING ARGON Feb. 7, 1928.,

Filed Oct. l5, l926 mumb-MUMWL KUNRX KHOEMGEOU m WLNNEXOND 4 l v f DANNENBAUM, Gl? FRANKFURD, IEENNSYLVANA-, ASSGNOR TO PACIFIC .llilllillttltitmlt 'CORPCtB/ATIOlN, OF IEHILADELFHIA, IPENNSYLVANIA, A5, CUEPORATION tilt W' t tlmltl'ttllhl.

PROCESS 0F OBTrtltllhlG: ARGON.

Application' led Gctober 13,1926; Serial No. llllfllo.

:this invention relates to an improved ticat-ion. lt is true, oi course, that tor t5 method ot obtaining argon of a high degree the separation of nitrogen from argon. aboli purity trom gaseous mixtures containing sorption ot the former by heated metallic air-,gon and nitrogen. i calcium, magnesium or lithium, by calcium t argon `:t'or commercial use is at present carbide or by lime and magnesium has been obtained by the complicated and compaia proposed, as has been combination ofthe ni- 60 tively costly method oli liquei'action or air. trogen with oxygen to form nitric oxide, rllhe argon obtained in this way is on the under the inuence of the electric arc. average et a purity oi about 85%. My in- These methods are, however, ot little, if any,

.n vention embodies an economical method olf practical value.

obtaining argon which may be, it' desired, llt is the object of the present invention 65 ot considerably over 85% purity, starting to provide an' improved method for conceneitlier with commercial argon or with gas trating argon -in gaseous mixtures ,containet a lovv argon concentration. ing nitrogen and argon. While adapted for tt lin electing the separation ot argon from the separation ot argon from any proporthe other constituents of the atmosphere by tion oi' nitrogen the method is particularly 70 the liquetaction method, by suitably varysuitable for obtaining 'argon of high purity the process and apparatus the argon. trom the argon concentrate above referred may be made to accompany the oxygen or to or `from argon of commercial grade, which ,tu the nitrogen :traction as may be desired. lt latter contains approximately 85% argon would seemthat as a general proposition and 15% nitrogen. the latter would be moredesirable, and, 1n @ther objects and advantages of the intact, it appears that when the argon vdoes vention will be apparentes it is better ungo vvith the nitrogen a highly concentrated derstood by reference to the olloivin speci-- argon in morereadily attainable.. riication in which its preferred einbo iments .ha argon is obtained from the air liqueare described. a@ faction column, in the 'form ot argon con- `The process consists in causing the nitrocentrate, it is greatlydiluted with nitrogen in the nitrogenargoncontaining gas, geen and oxygen, the relative proportions o'l;l trom which oxygen has; preferably been my which depend upon Whether the argon has -preliminarily removed by any suitable accompanied the nitrogen or the oxygen means, to combine With hydrgen to term an traction., rlFhe :further concentration of this ammonia, by submitting the gaseous mixto render it tit for any purpose as argon ture, repeatedlyfand preferably under prespresents a serious problem. li the principal sure, to the action ot a catalyst capable ott diluent is oxygen its removal by liquelaction edecting the desired combination of nitrogen in ditticult on account ofthe fact that there and hydrogen. rllhe ammonia formed is re'- au is but a small diderence in the boiling points moved, for example, by condensation and et oxygen and argon. rlEhe oxygen may, oit theV remaining hydrogen is eliminated, tor course, be removed h'y burningwith admixed instance, by causing it to combine With oxyhydrogena "lhefhydrogen for this purpose" gen, free or combirfed. lit 'free oxygen is should be. ot a high degree of purity. lts used, any excess may be taken out by combi. at

cost andthe tact that no useful product is nation thereof with metallic copper. llhave obtained as a consequence of. the combustion found that this method of procedure is egti .malte oxygen re' ioval step a costly one. tectiv'e :tor the economical concentration et ,my Furthermore, When the oxygen has been reargon. Moreover, an important advantage moved the problem ci eliminating the alot the process lies -in the tact that a valuable tocl 'trays considerable proportion of nitrogen luy-product, ammonia, is produced.

" nemej'nusD lt is important `for the best results to ob* @n the other'hand, it the major impurity serve certain precautions regarding the he argon is nitrogen-Which will be true quality ot hydrogen used in the proc Y t he argon, as may advantageously be the ess. Thus, particular pains should be talren ma caee,has been separated with the nitrogento avoid the presence oit catalyst poisons, 'there has been heretofore only one practical and especially sulphur compounds, and oxy-` ot'separationavailable, namely, recgen, t'ree or combined. rThe amount ot hym drogen added is best at least that theoretically necessary for the complete transformation of all the nitrogen to ammonia.

The combinationi` of nitrogen and hydrogen may be brought about under very high or comparatively low pressures. If the pressure is very high-that is,- of the order of magnitude usually referred to as hyperpressures, say 400 to 1000 atmospheres--the catalyst need not be so active as when lower pressures, below 400 atmospheres, are emaployed; this being due to the more favorable equilibrium conditions at hi her pressures. It will, of course, be desirab e in any event to suit the activity of the catalyst to the pressure employed, since, the dilution of the nitrogen and hydrogen with inerts being unfavorable ..to the ammonia equilibrium to begin with, all other conditions should, as nearly as is possible, be arranged to favor the maximum ammonia formation.

. I have found that at 1000 atmospheres a catalyst composed of 98 partsof ferrosoferric oxide and 2 parts of alumina works satisfactorily, while at 300 atmospheres a catalyst 4ontainin in addition 0.75 parts of potassia suits t e` urpose. Other catalytic materials may, o course, it being understood that the lysts herein described are old c aimed perse.

The nature of my invention will be more fully understood by reference to the following example in which one embodiment of the invention is described with reference to the accompanying drawing, in which- The gure is a diagrammatic representation of an arrangement of apparatus adaptedfor the practical application of the 1nvention. A

A gaseous mixture containing 2-parts by volume^of argon and 22 parts' of nitrogen (i. e., containlng a ratio of argon to nitroglen over seven times that in air), and free om oxygen and oxygen compounds, enters the system at A. under atmospheric pressure.

ydrogen free from catal st poisons'is ad mitted thru the valve B, w ich is adjusted so that 66 parts of hydrogen is added to every 24 part of argon-nitrogen mixture. The gaseous mixture is delivered to the compressor C, which compremes it to '900 atmospheres. At this pressure the mixture passes thru the converter D, where it, contacts with a catalyst composed of 98 `parts ferroso-ferric oxide and 2 parts alumina. During this contact, combination of nitrogen and hydrogen to form ammonia occurs. The ammonia in the gases leaving D is condensed gy external' -water cooling in the condenser ,and withdrawn by way of the receiver F. The gases' pass onto a second cou-- be employed, specific cataand are not verter G, employing the same catalyticema-f D rial as in D. Gonjoined to G is a circulatlngu pump H by means of which the gaseous mixture leaving G--after the ammonia has been condensed in J and collected in K--is recirculated thru the converter Gto increase the argon concentration to the value desired. The expansion valve L is adjusted so that the nitrogen content of the gases withdrawn therethru is not more than 4%. Thru the valve M oxygen is admitted, the valve being set so that at least 7 volumes of oxygen 1s added to every 100 volumes of the gaseous mixture. In the oxidizer N the gases pass over a heated m'ass of metallic copper catalystwhich serves to effect the combustion of the hydrogen. The resulting water is eliminated inV part in the condenser O, to be collected in P, and completely removed in the calcium chloride dryer Q. The dry gases, containing argon, nitrogen and oxygen then pass thru the deoxidizer R, containing heatcd metallic copper', which removes the oxygen forming copper oxide. The 0ras leaving R contains over 95% argon, the balance being nitrogen.

The process h'ereinbefore described affords an economical and satisfactory method of obtaining argon of a high degree of purity from gaseous mixtures containing argon and nitrogen. `It will be apparent that a as containing as high. as 95% argon may ge prepared by thisprocess and, as already stated, the argon concentration may be i11- creased in a mixture containing .initially 85% argon. It will likewise be apparent that other argon percentages may be obtained ran ing above 50% argon by the process herein escribed.

As many apparently widely diiierent embodiments of this invention may be made without departing from the spirit thereof,

4it is to be understood that the invention is not limited by the foregoing embodiment except as indicated in the appended claims.

I claim:

l. The process of concentrating argon which consists in subjecting a gaseous mirtture of hydrogen and nitrogen containing upward of 115 Volume of argon per volume of nitrogen to the action ci' a catalyst ac tive for the formation of ammonia from nitrogen and hydrogen.

2. The process yoi concentrating argon which comprises subjecting a gaseous mixture of hydrogen and nitrogen containing upward of ,JU volume of argon per volume of nitrogen to the action of a catalyst active for the formation of ammonia from nitrogen and hydrogen, removing from the gaseous mixture the ammonia thus formed and eliminating the remaininghydrogen.

3. The process of concentrating argon which comprises subjecting a gaseous mixture of hydrogen and nitrogen containing upwardof 115 volume of argon per volume o nitrogen to the action of a catalyst active for the formation of ammonia from nitrogen and hydrogen, removing from the gaseous mixture the ammonia thus formed'and eliminating the remaining hydrogen by combination thereof Wit-hvexygen.

4. The process off `concentrating argon Which consists in subjecting a gaseous mixture .of nitrogen and hydrogen' containing upward of U volume of argon per volume of nitrogen repeatedly to the action of a catalyst active for the formation of ammonia from nitrogen and hydrogen, with' removai of ammonia between periods of catalytic contact.

5. The process of concentrating argon which consists in subjecting a gaseous mixture of nitrogen and hydrogen containing upward of -116 volume of argon per volume of nitrogen repeatedly to the action of a catalyst active for the formation of ammonia from nitrogen and hydrogen, with removal of ammonia between periods of catalytic contact, the hydrogen in the gaseous mixture thus obtained being removed by combination thereof With oxygen.

6. The process of concentrating argon which consistsin subjecting a gaseous mixture of nitrogen andhydrogen containing argon repeatedly tothe action of a catalyst active for the formation of ammonia from nitrogen and hydrogen, with removai of ammonia between periods oi catalytic can tact, the hydrogen in the gaseous mixture thus obtained being removed 'oy combination thereof With'oxygen.

7. The process of concentrating argon which consists in subjecting a gaseous mixture of hydrogen and nitrogen containing upward of 5A Volume of argon per volume of' nitroo'en to the action of a catalyst active for the fbrmation of ammonia from nitrogen and hydrogen.

8.*'l`he process of manufacturing argon in concentrations above 50% which consists in subject-ing a gaseous mixture of hydrogen land nitrogen containing upward of il@ Volume of argon per Volume of nitrogen to the action of a catalyst active for the formation of ammonia from nitrogen and hydrogen.

In testimony whereof I aiiix my signature.

WALTER DANNENnAi-TM.

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