US1830408A - Apparatus for the dehydration of impure ethyl alcohol - Google Patents

Description

Nov. 3, 1931. E. RICARD 1,330,408

APPARATUS FOR THE DEHYDRATION OF IMPURE ETHYL ALCOHOL Filed July 24, 1929 4 Sheets-Sheet l ALCOHOL DEHYDRATING COLUMN ALCOHOL INVENTOR 3404. med/14.

ATTORN EYS Nov. 3, 1931. E. RICARD 1,330,408

APPARATUS FOR THE DEHYDRATION 0F IMPURE ETHYL ALCOHOL Filed Jill 24, 1929 4 Sheets-Sheet 2 AlCOHOL ENTRMNING LIQUID MIXTURE WATER AND METHYL ALCOHOL WATER METHYL ALCOHOL DEHYDRATING COLUMN A LCOH OL BY FAA-@111: W ug'U: BJAM Wu.

ATTORNEYS |NVENTOR 104.

ABSOLUTE Nov. 3, 1931'. E, r-M ARD 1,830,408

APPARATUS FOR THE DEHYDRATION OF IMPURE ETHYL ALCOHOL Filed July 24, 1929 4 Sheets-Sheet 3 WATER ETHYL ALCOHOL METHYL ALCOHOL ALCOHOL DEHYDRATING COLUMN ABSOLUTE ALCOHOL JNVENTOR BY wddifi Wuw BBMWM ATTORNEYS E. RICARD 1,830,408 APPARATUS FOR THE DEHYDRATION OF IMPURE ETHYL ALCOHOL Nov. 3, 1931.

Filed Jul 24. 1929 4 Sheets-$heet 4 lwcLuoms ORGANIC ALKAL: sans.

. INVENTOR 1a m 1 M0 DEHYDRATING COLUMN ALCOHOL ABSOLUTE ALCOHOL METHYL ALCOHOL nary rectifications ordinarily employed,

Patented Nov. 3, 1931 UNITED STATES- PATENT OFFICE nLoI. RICARD,

OF MELLE, FRANCE, ASSIGNOR "1'0 U. S. INDUSTRIAL ALCOHOL 00., OF

- NEW YORK, N. Y., A. CORPORATION OF WEST VIRGINIA APPARATUS FOR THE DEHYDRAT I A Application filed July 24,

My invention relates particularly to an apparatus for the dehydration of ethyl alcohol containing impurities.

The object of my invention is to provide an apparatus by means of which the alcohol 'containing impurities may be dehydrated so as to obtain absolute alcohol inan advantageous manner and without unnecessary prelimiof the alcohol. The process for the dehydration of ethyl alcohol which is based upon azeotropic action as cannot be used when the alcohol to be treated contains certain natural or added impurities whichare of such nature as to gradually accumulate in the main distilling apparatus. Such impurties are prejudicial to the dehydration, and will even stop the operation altogether.

To obviate thatdifliculty, recourse maybe had to a preliminary rectifying operation, 0 an expensive nature, whereby the impurities may be eliminated, but in the case of impurities which are diflicult to eliminate, such as methyl alcohol, it becomes impossible to obtain the desired results. The present invention provides an apparatus with which any such preliminary rectification is obviated and in which the impure commercial alcohols may be dehydrated directly,

The impurities considered in the process for which this apparatus is particularly intended may be of widely varying character, but in general they are usually characterised by the following properties: They are more sulphuric ether,

volatile than, alcohol and they are generally soluble in water orunable to form either with water or with alcohol, taken separately, binary mixtures having a minimum boiling point. Among the products possessing these qualities may be mentioned acetic aldehyde, acetone, ethyl formate, methyl alcohol, and the like, which are given Further objects of my invention will appear from the detailed description of the same hereinafter.

While my invention may be modified in many particulars, for. the purpose of illustration I shall describe only certain types of f 2, but with ION 0F IMPUBE ETHYL ALCOHOL 1929. Serial No. 380,567.

apparatus as shown in the accompanying I an apparatus which may be used in carrying out my invention showing thereon equipment which is especially adapted for accomplishing the purposes above referred to asone embodiment thereof;

Fig. 3 is a diagrammatic representation of another form of apparatus which may be used in carrying out my invention; and

Fig. 4 is a diagrammatic representation of an apparatus similar to that shown in Fig. a'further addition to the same, as hereinafter described.

In describing my said apparatus, I will briefly mention, process for the hol according to the practice as set forth in application Serial No. 688,050 aforesaid.

The alcohol of ordinary, approximately 95%, strength is fed by a pipe a into a distilling column A provided with a steam heating coil S. The resulting vapors evolved through a pipe a are condensed in a condenser C. A part of the hot liquid returns to the column A through a pipe 0. Another part is cooled in a cooling apparatus 0 and is discharged into a separating chamber 1) in which it separates into two layers. Each layer contains the three substances, water, ethyl alcohol and an entraining liquid such asbenzol, for example, which may be fed in by the pipe at with the alcohol. One layer," for instance the top layer, contains the major part of the entrainin liquid which is returned to the column through a conduit 1'. The second layer, herein the bottom layer, is treated in a small distilling apparatus including two columns B and B. The apparatus B is comprised of a column provided with a steam coil T and serves to remove the whole of the entraining liquid from the liquid layer, which is supplied with reference to Fig. 1, the dehydration of purified alcodischarged from the by meansof a valved apparatus as shown in Fig. 2. tus is constructed and operates inthe same thereto through a pipe d. The entraining liquid is drawn off from the column B as a vapor mingled with a small amount of a vapor of the other two constituents of the layer and, thus, returned to the pipe a by the pipe 03. The other two constituents, comprising alcohol and water, are drawn off from the column B into the column B through a pipe h. The column B is heated by a steam coil U and serves to remove, in the form of a vapor, alcohol of a high strength through the pipe it to a condenser k2, which delivers the condensate partly to the top of the column B by a valved pipe 7L3, but mainly by a pipe is to the dehydrating column A. The water is discharged from the column B by an outlet pipe m. The absolute alcohol is dehydrating column A outlet pipe p, which is connected to a cooler p having a vented outlet pipe 92. In the case where an apparatus of this type is fed with an alcohol containing for example, of methyl alcohol, it would be found that methyl alcohol'has no exit from the apparatus as it does not descend to the bottom of the column to be drawn off through the pipe 72 with the absolute alcohol, nor does it pass out with the aqueous materials issuing from' the bottom ,of the column B, but it is found that it collects at the top of the column A and will be prejudicial to obtaining the proper usual ternary constant boiling mixture. Accordingly, the decantation in the separating chamber will be hindered' and will finally be revented, thus preventing the dehydration rom continuing. ccordingly, in carrying out my invention, an outlet for methyl alcohol, when present, is provided for.

I have, thus, provided for this purpose an his apparamanner as the apparatus shown in Fig.1 so far as the parts disclosed in Fig. l are found in Fig. 2. In additionthereto I have pro Vided, however, an apparatus for carrying out the purpose above referred to. For this purpose I have provided a valved pipe 1 for drawing ofl from the separating chamber D a part ofthe decanted layer, in this instance the lower layer, in which the methyl alcohol, etc-., isfound in the A greatest quantity. This 1s conveyed bythe pipe 1 to a distilling column 2 provided withv a steam heating coil 2. The mixture therein is distilled so as to form a binary azeotropic mixture which collects at the top of the column 2 and is driven off througha pipe 2" to a condenser 3. A part of the condensate flows back through a pipe 4 to the top of the column 2 and a part is discharged through a conduit 5 into a scrubber 6 of any desired type. Water from the tank. ;8 is delivered through a valved pipe 7 to the scrubber 6. Water dissolves the methyl alco'" hol, thus producing a plurality of layers column 12, and the remainder duit 10 to the pipe (l and thenceto the dis tilling column B. Ihe lower layer in the scrubber 6 is carried off by a vented pipe 11 to a distilling column 12 in which the two liquids, comprising methyl alcohol, etc., and water, are separated. The methyl alcohol, etc., is evolved from the top of the column in the form of a vapor and conveyed by a pipe 12 to a condenser 12", part of the liquid condensed being returned by a pipe 12 to the oil by a valved outlet 13. The water from the column 12 is carried away by an outlet pipe 14. For heating the column 12' there is, as shown in the drawings, a steam heating coil 14. By carrying out the process in this manner I have obtained a continuous abstraction of the methyl alcohol, thus avoiding the accumulation of the methyl alcohol in the top of the distilling apparatus so that, as a consebeing carried quence, the distilling process may be carried on continuously without any interruption.

Instead, if desired, I may carry out the 0 eration in a somewhat simpler manner. 11 the case of not dealing with an lmpurlty, WlllCll w ll tend to form a binary azeotropic mixture with the entraining liquid, the impurity in thealcohol can be made to separate directly out inthe pure state the distilling apparatus. accordingly, I am able to eliminate the scrubber 6 and the distilling column 12. In carrying outthis form of my invention I utilize an apparatus such as shown in Fig. 3. The apparatus shown in this figure comprises the parts which are showndn Fig. 1 but in addition thereto has certain features added to the same as hereinafter described. The lower layer from the separating chamber D containmg' the water, ethyl alcohol, entraining liqui and a large percentage 'of impurity, is discharged through a conduit 20 into a pipe 21 arranged to receive Water from a tank 23 through a pipe 22. The pipes 21 and 22 are arranged to intermingle the said lower layer and the water, especially with the aid of a plpe 25 connected thereto, which leads to a separating chamber 26 where the liquid forms into a. plurality of layers. The entraining liquid accumulates in the upper layer and is returned by a pipe 27 to the pipe e, Where it is returned to the dehydrating column A. The bottom layer, which contains the water, ethyl alcohol and methyl at the top of column B.

he vapors accumulating in the In this instance,

. alcohol, is disrged throu h a conduit 28 to the distilling,

We ,Hble

the impurity or the methyl condensed and discharged 29. From the lower part column B there is conveyed alcohol, which is through a conduit of the distilling to thecolumn B a mixture of water and methyl alcohol, which is distilled therein as In the case Where,

hereinabove referred to. instead of one impurity the mixture contains a certain, number-of impurities,

3, would be carried out in the operation, 7 10 same in the apparatus shown in Figs.

in treating the 2 and the same manner except that the mixture of impurities to be eliminated would be discharged through the conduit 13 in Fig. 2, or 15 Fig. 3.-

ration and purification of alcohol is to be tillationl "F31 example, iso-amyl the conduit 29 in In the, case whehe the sim ultaneous v dehycarried out containing impurities of ai'widely varying character such as ethers, acids and 29 tail products in general, I can resort to a;dif-

ferent procedure as My process 1s, thus, ment of raw commercial a hereinafter described." applicable tothe treat lcohol or to alcohols to be again treated after having been used as solvents in certain branches of manufacture.

In carrying out the processes for apparatus is particularly valuable,

the impurities last menhol containing which my with alcotioned, I may proceed as follows, for example: I'neutralize the acids saponifiable and saponify the compound ethers by the continuous measured addition of an alkali at the top of the distilling apparatu 35 below the region in which impurities, if any, are operation s and at a point the first distilled being eliminated, the being performed in this manner in order to obviate the rectifying of the first distilled impurities, give rise to organic salts or esters thus because this would an odor difiicult to eliminate. The

formed are soluin alcohol andin the tail products, and,

accoi diiigly reach'the-lower part of the distilling column whence they are discharged.

' In casethe product treated contains acids but not ethers, I may,

if desired, neutralize the acids by the continuous measured addition of an alkali. If ized they will act the products are not neutral in the same manner as the tail products and discharge therewith as above indicated.

" I eliminate the tail products, the boiling point of which is higher than that of alcohol,

and which consist usually of the higher alcohols, acetal, aldol, croton-aldehyde, the furfurolic bases, amines, series, the heavy ethers wh1 aldehydes of the fatty ch are not saponified, the volatile fatty acids, and the like, by

causing-the same to descend during the dehyproducts will be accumu lated. The said products may be removed in the .form of a liquid. or vapor by means of a discharge valve, and they are then rectified in an auxiliary distilling column where they are freed from' ethyl alcohol. All of the above-mentioned last-distilled products are insoluble, or but slightly soluble in water, and thus, will aiford mix'thresvvhich have a constant boiling point, and which .can be distilled below 100 C. In fact, the presence of a small amount of water, which lowers the boiling point in the rectifying process, makes the separation of said products very difficult, but in the absence of water their boiling point remains unchanged, but this boiling point, thus, will readilypermit their fractional dis- I alcohol will distill-at 95 C. when in the presence of a small quantity of water, and at 131 C. when it is anhydrous. In the first"instance'its boiling point differs from that of alcohol by only 165, while in the second instance it differs by 53 C. i

The following example, referring to the apparatus shown in Fig. 4, will exemplify the process as carried out in the form of my invention ust described. The apparatus shown ,in Fig. 4 has all of the features as shown in Fig. 2 but in addition thereto I have provided an equipment for introducing the alkali and takin g care of the constituents present in the treated alcohol which boil at a hi her point than the absolute alcohol whic is drawn off by the pipe p in the mamer above described. Therefore, in said apparatus it will be understood that the apparatus above described in detail will eliminate the acetic aldehyde, acetone and any methyl alcohol in the product. Any ethyl acetate, which often forms the chief impurity of alcohol, has a tendency to form in the middle part of the column A. Through a pipe 30 connected to the column A,,I introduce a concentrated solution of caustic soda whichmay be either an aqueous or alcoholic solution, which, accordingly, spreads out upon the plates in the column. During the heating of'the column A the acids in the alcohol are neutralized and the ethers are saponified. The organic sodium salts resulting therefrom are soluble in alcohol and descend to the bottom ofthe column A, where they are evacuated with the lastdistilled products, a number of plates A being added for this purpose. These last-distilled products, in crude state, pass out through a pipe 32 which conveys them to a. distilling column 33 steam-heated by means of a coil 34. The vapors from the column 33 escape by a pipe part of the condensate being returned by a valved pipe 36 to the column 33, andthe remainder being conveyed to the plates A through a pipe 37. The last-distilled prod- 34 to a condenser 35, a

only oneof' the layers vapors from said last I nected so as'to separate out said mpurity flingth rapers fronrsaid lastmentienedcob I I 0 11mm 3' by inea'nsof "a pipe-38,01 theymay bet-I hoved 3 individually at different heights, according I "to thei'r' boilingpoints, 4 through valVefd-pipe's'39', 40,-etc. 1

"WhilefI have-described my invention above 1 inide a l' Ijvishittofbegunderstoodthat many changes mafie made therein vVft hou'td e'part g from the Piritof the same. Ifclaim-z 0:51" 1 lfiflhil apparatus for dehydrating alcohol containing a liquid impurity, comprising a' dehydration column, aflcon'denser connected thereto, a separating"chamber connected to] the condenser to receive the -condensate in the form "p t efiquidlalelfilheret' thereto adaptedto- V p arating chamber, and

from'the alcohol, comprising a scrubber] 6. An apparatus for dehydrating alcohol" containing liquid impurity, comprising a dehydration column, a condenser connected thereto, a separating form of "a'plnrality of liquid layers theref1'om, a column'connected thereto adapted to receive only one'ofthe layers of liquid from the separating chamber, and means for treatumn'conne'cted-so'asto separate out said impurity from the alcohol', comprising a scrubber anda'sti'll'connected to the scrubber.

l. 5 An :1 pp'aratu's for dehydrating alcohol containing a high boiling lmid imd hydratmumn, an t 6 column, an alkali'feed for 'the 'alcohol column, an absolute alcohol draw-01f pipe connected to the column, and means for recovering" the high boiling impuripurity, comprising a tie,:;, includingfhe product produced b th addition of the alkali. v

An apparatus for dehydrating aqueous boiling liquid ime 'fi l' is i a r ti i an ee'dfor thefcolunin, an alkali feed for thealcohol absolute alcoholdraw W d to the column, and ineansy e' liigh boiling impuritiqsfinalcohol containing a high purity,

alcohol off "pipe cor rne'ct or recon 111 p p and means for'treatmtg the' apors from sa d last mentioned colseparate out said 1mchamber connected to chamber connected to the condenserto receive the condensate in the ofthe of the alkal Intestimony thatI claim the fore have hereunto set'my hand this 5th day of I y I v v Jilly, 1929.

H AH

i,".compris'ing a column.

going, I

VELOI RIGARD.

Images