US1541175A - Process for producing styrol and its homologues from aromatic hydrocarbons - Google Patents

Description

June 9, 1925. 1,541,175

OSTROMISLENSKY ET AL PROCESS FOR PRODUCING STYROL AND ITS HOMOLOGUES FROM AROMATIC HYDROCARBONS f Filed May 7 1924 Hurwe hm/gfx Patented June 9, i925.

UNITED STATESPATENT OFFICE.

IWAN OSTBOMISLENSKY AND MORRIS G. SHEPABD, OF NEW YORK, N. Y., ASSIGNOBB TO THE NAUGATUCK CHEMICAL COMPANY, OF NAUGATUCK, CONNECTICUT, A

CORPORATION OF CONNECTICUT.

PROCESS FOB PRODUCING STYROL AND ITS HOMOLOGUES FROM AROMATIC HYDRO- CARBONS.

Application led May 7,

To all whom z't may concern:

Be it known that we, .IWAN Os'rnoMis- LENsKY and Monni's G. SHEPARD, a citizen of Russia and a citizen of the United States, respectively, both residents of New York, county and State f New York, have invented certain new .and useful Im rovements in Processes for Producing tyrol and its Homologues from Aromatic Hydrocarbons, 'of which the following is a full, clear, and exact description.

This invention relates to the production of styi'ol and its homologues from hydrocarbons havin eight or more carbon atoms. such as ethyl enzol, xylol, homoloues and analogues thereof, by pyrogenic ecomposition. s l

The objects of the present invention are to provide a process of the kind describedV `which shall produce a high yield of styrol, and its homologues, which shall be economical and can be carried out in a practical way with simple apparatus.

The invention accordingly consists, of a f process for making styrol and/or its homoogues which 'comprises heating a hydrocarbon having at least eight carbon atoms and at least 10 hydrogen atoms to a tem-l perature of approximately 450 C. to approximately 700 C., and partially decom-l posing,r the hydrocarbon to form a compound havin the general formula ALCH: CH, where r. is aryl.

This case is a continuation in part of our 'application Serial No. `648,751, tiled June In carrying out the invention the apparatus shown diagrammatically in the figure may be ein loyed. It comprises a source lof ,carbon dioxide or other neutral gas. led `in by a Pipe 1 through a tlowmeter 2 by means o pipe 3 into the interior of an iron pipe 4 which isl heated in any desired manne!` to the re uired temperature, as by gas burners 5. Jommunicatinfv also. with this tube 4 through a valve 6 and sight glass 7 is a container 8 for the hydrocarbon. The temperatureis determined by means of a thermocouple 9 arranged kin the present embodiment to record through the indicator 10 the temperature of the gas in the interior of the tube at the \middle. Electric or other heating means may be employed if desired. The tube 4 leads into the Liebig condenser 1921. Serial Fc. 711,583.

vcharged 4at 16. The manometer 17 acts simultaneously as a pressure gauge and safety device. The baiiies 18 are used to insure that the fluid `is uniformly heated.

The processes for producing styrol, its homologues and analogues may be divided into two grou s, which are designated as follows: (1) ehydrogenation' of ethylbenzene or its homolo es at high temperatures (450-700 0.); an (2) splitting oi hydrocarbons from various homologues or analogues of benzol which have more than two gtomscof carbon in a side chain at 500- 1. Dehydrogenation of ethyl benzol.

and/or its homologues at high temperatures The general formula for the reaction here occurring is Ar.CH,.CH :Hd-ALCH CIL, where Ar. is aryl.

Under this group comes the treatment of ethyl benzol, the procedure for treatment of which is as follows: Eth l benzol is run from container 8 into the interior of iron tube 4 at a measured rate.4 The a paratus having been previously cleared o air. by passin a stream of carbon dioxide or other neutra gas from the pipe 1 therethrough and the iron tube having been heated up to approximately 650 C. as shown bythe indicator 10, this temperature is maintained throu hout the run within plus or minus 15 The rate of iow of ethyl benzol is maintained at approximatel 15 to 20 gm s./ min. and the rate of ow o carbon dioxide as indicated by the ilowmeter 2 at 50to 60 c. c./mn., the pressure .in the heating chamber 4 being atmosheric. or these conditions of tem ofiiow should be 2 in. an

rature and th total l ap roximatel The internal diameter ofv the tab: n

of the heated portion (that withinthe nace is 54 in. The total internal. volume of the reacting portion of the tube is thereforef170 cu. in. in roundnumbera The process is continuous, lt'being 'only uw sary to interrupt for repairs, etc. The Areaction which takes place upon passage of the ethyl enzol through the heated tube is as follows:

Other reactions may take place and do take place to produce gas, carbon and tarrv products. The styrol and tarry products are collected together in the container-13 while the gases pass to the gas holder 14. A process for separating the styrol from the tarry products is set forth in our copending a plication Serial No. 711,584, filed May i; 1924. This process comprises distilling the mixture with steam, separating the distillate from water and drying it. The dried roduct is placed in an autoclave and heate ap roximately for 16 hours at ,180 C.-200 Polymerization of styrol to form metastyrol occurs. An accelerator of polymerization maybe employed, if desired. With benzoyl peroxi e as an accelerator polymerization may be accomplished in approximately 8--12I hrs. at 180 C. After polymerization the autoclave is opened and its contents subjected to a tractional distillation, the final residue remaining above 145 C. representing metastyrol. Under the conditions ofpressure and temperature and using an iron tube as indicated, the amount of styrol produced from a thousand gms. of ethyl benzol is approximately 250 gms. This quantity of roduct represents an eicieney of approximately 32%.

The term elliciency as used, means the per cent of the theoretic yield of styrol calculated on the basis of the actual ethyl benzol consumed in the process. In carrying out the above process, 220 gms. of ethyl benzol was recovered per 1,000 gms, of ethyl benzol used, which means that 780 gms. of ethyl benzol were consumed. The etliciency therefore on a'percentage basis is -250X100-:-780 or 32%. This calculation neglects the slight dilerence in the molecular weight of ethyl benzol (106) and styrol Instead of ethyl benzol which has the formula. GSH, the isomer xylol which also has the formula GSH, may be employed under substantially the same conditions as those indicated above for ethyl benzol. The reaction may be expressed as CH4 (C1102: C,II,CH:CH2+H,. The amount of styrol produced from 1000 grams of xvlol is approximately 50 grams and the eliiciency approximately 20%.

The conditions given in the preferred embodiment above, have been varied in order to determine among other things, the optimum temperature for various tube materials. the optimum rate of flow of ethyl benzol and the value of the use of a neutral gas to promote the How of ethyl benzol through the heating tube.

An iron tube, due to the ease with which such tubes may be procured, has been indicated in the preferred embodiment above but numerous tests on other tubes show that iron may be replaced if desired. For example, quartz or copper tubing may be used in which case results quite similar to those with the iron tube are obtained. An exception is that of nickel. When nickel gauze was placed in an iron tube the results were not as satisfactory, the tendency being to form large quantities of gas and carbon at the expenseof the desired product, styrol. The optimum rate of flow established will vary with variation of other factors of the apparatus and process, for instance, variations in the shape of the heating chamber and the distribution of heat in this chamber would influence the rate of flow and variations of pressure within the chamber.` would also influence the rate of flow. There is apparently a relationship of the volume in which V is the volume of the heated portion ofthe tube in cubic centimeters, R the rate of llow of ethyl benzol into the tube in grams per minute; T the temperature of the interior of tube at the middle point in degrees centigrade; and K the parameter varying betweenthe values .8 and 1.2, the oitlmum efliciency being secured when I :1. The optimum elliciency is about. 36%. This equation holds for all practicable rates of flow and all practicable sizes of tubes.

In order to determine the effect of the carbon dioxide or other neutral gas employed, a run was made using the iron tube as in the preferred embodiment in which no neutral gas was employed and it was found that the results were quite similar to those obtained when the neutral gas was used. However, the operation of the apparatus is simplified by the use of this nelltral gas as the regulation of the rate of flow of ethyl benzol is thereby facilitated.

Tf any unchanged ethyl benzol or xylol is collected, this material may again be run through the apparatus to produce st vrol with an efficiency substantially the same as given b v the original ethyl benzol or xylol.

Other gases such as nitrogen and steam may be used to replace carbon dioxide the gas promoting How through the heat ingr chamber. The process may be run con llo ' may be carried out as follows:

tinuously. It requires little attention and is relatively economical.

In addition to ethyl benzol and xylol mentioned above, various othermaterials hav been similarly treated' falling within the present group. The products obtained an l the raw materials are as follows: (a) orthomethyl styrol from orthomethyl ethyl benzol, (b) para meth l styrol from para methyl ethyl benzol, {c} symmetrical dimethyl styrol from 1. 3. 5. dimethyl ethyl benzol, and (d) ethyl styrol from diethyl benzol.

The starting points for (a) and b) may be obtained b ethylating toluol. ymmetrical dimethy styrol may be obtained by similar ethylization of xylol. The following is a tabulation of results obtained in the dehydrogenation of the isomer xylol and homologues of ethyl benzol into those of ,styrol followin a 's1milar processto that set forth for dehy rogenation of ethyl benzol.

A Boilingtem- 140 176-185 145-100 16o-165 130 peratureof original |(nci)xture B Nature of xy1ol- 1.3.5 di- Ortho- Parme Diethylactive hymethyl methylthylbenzol1 drocarbon. ethylethylethylbenzol benlol benzol C Amount in lgms. 0.62 gms. 0.5lgms. 0.52gms. lsgms.

grams per minute. D Durationoi l hr. 7 6h. 45m. 3h. 15m. 7hrs. 47 mins.

lprocesa rn s. E ixture 1000gms-250gms. 109gms. 217m. 849 gms.

subjected to pyroization ngms. F Tempera- 650 6to-650 6804520 G40-650 650 tureofiun nace (C). G Liq uid 944mm. 225gms. 97gms. lgms. 800 gms.

products obtained. HDryHydro- 833m. 178gms. sgms. l'gms. B84gms .carbons distilled w l t h steam. lNature o1 Meta- Ortho- Parame- E th product. meta methyl t h yl styro .1 styrol obdimestyro. styrol. tamed. t h y l styrol. .I Content oi 5.7% 31.7% 28.6% 35.7% 23.8%

styrol or .Mm f'.-

081108 Il distillate '(steem) by analysis Whether the process is carried out in iron or quartz tubesthe results are substantially as given above. Actually the above results were gotten using an iron tube for xylol and grou l as follows: Ar.C,H,R=RHl-Ar. H:

a quartz tube for the other substances. The quartz tube had the following dimensions: 1" diameter by 27 long. It has been found that the relationship of the volume in the heating chamber, the rate of flow and temperature exists in a similar Way for products other than ethyl benzol which may be expressed mathematically by the formula given in connection with the process employing ethyl benzol.

nstead of using ethyl benzol or its homologues separately, mixtures of ethyl benzol and/or of its homologues may be passed through a heated tube and a solution containing styrol and its homologues or the homologues alone obtained. For this purose the mixtures of ethyl benzol and its omologues may conveniently be obtained by eth latin mixtures containing benzol, toluol an xylo as for example the fractions obtained from coal tar, gas tar, etc. boiling from 80 to 130 C.

Ethyl benzol, xylol, etc. containing styrol in solution may also be used as raw material, for example, ethyl benzol which has already been subjected to the pyro en'ization action of the hot tube. Such ethy benzol or xylol, etc. containin through the tuge. he result of such action is to enrich or increase the concentration of styrol.

For example, if a solution containing around 14% of styrol in eth l benzol is passed through the hot tube un er the usual conditions as set forth in our application Serial No. 648,751, filed Junev30, 1923, the resulting raw product would contain around styrol, whereas ordinarily using pure ethyl benzol the styrol content would run around 20%. The ethylbenzol recoverable from this raw product is essentially in the same proportion as that from pure ethyl 2. Splitting oil' hydrocarbons from various homologues or analogues of benzol which have more than two atoms of carbon in the side chain at G-700 C.

The reaction involved in this I Iis 2, where Ar. is aryl and R re resents an alkyl radical. This process has een investigated in connection with the treatment of cymene.

In carrying out the process with cymene the following reaction occurs:

Specifically the process emploing cymene ymene is introduced from container, 8 into the tube 4 of quartz at a rate of .5-.6 ams per minute. The tube is heated to 650 C., the diameter of the tube being 25 cm. and length subjected to heating 67 cm. A current of carbon dioxide at low pressure is passed from pipe 1 through the tubecontinuously during the st rol may be repassed' whole process. The liquid reaction products l condense in the receiver 13 which 1s water cooled. The methane formed in the reaction may be collected in the gasometer 14. The product resulting from treatment of cymene methyl styrol appeared in the distillate and the remaining grams of liquid products in the distilling lask. An analysis of the distillate showed that it contained grams, i. e. 53.2% of paramethylstyrol, the

i main part of the by-products in this crude ticular it may be obtained from cheap varieties of turpentine which in turn are made by distilling shavings of pine-tree stumps with steam.

The processes described are simple and economical, and require simple apparatus only. They produce a relatively high yield of the desired product.

It will thus be seen that among others the objects of the invention above enumerated are. achieved.

As many apparently widely dili'erent embodiments of this invention may be made without departing from the spirit thereof, it will be understood that We do not intend to limit ourselves to the specific embodiment herein set forth except as indicated in the appended claims.

Having thus described our invention, what we claim and desii'e to protect by Letters Patent is:

1. A process for ina-king compounds of the type ArCI-I: CH2 where Ar represents aryl, which comprises heating a hydrocarbon having the general foi-mula ArCJLR where R represents a monovalent substitution to a temperature of approximately 450700 C.

(ill

Aand partially decomposing the hydrocarbon to forni ArCH: CH2. A

2. A process for making compounds of the type ArCHzCH2 where Ar represents` changed .\i'C,lLR, and the ArCH: CH2 therefrom. y

4. A process for making compounds of the type ArCH:CH2 where Ar represents aryl which com )rises passing a stream of an aromatic liydrocarbon having the formula ArCJLR where R represents an element through a conduit heated to appmximately 450-T00, and decomposing Sie *(zlLR portion thereof to yield A rCII:

5. A process for making compounds oi the type ArHzCH2 where Ar represents aryl, which comprises heating a hydrocarbon having the general formula ArC,H,R where Ar represents aryl and R represents hydrogen, approximately to 4-50-'700J C., and splitting ott' hydrogen therefrom to form ArCH: CH2.

A process t'or making compounds of the type ArHzCH2 where Ar represents aryl, which comprises heating a hydrocarbon having at least eight carbon atoms and at least ten hydrogen atoms to a temperature of 450 (lf-700o C. approximately, and partially decomposing the hydrocarbon to form ArCH CH2.

7. A process for making ArCHzCH3 where Ar represents aryl which comprises passing a stream of a vaporized aromatic hydrocarbon having at least eight carbon atoms and at least ten hydrogen atoms through a conduit heated to a temperature of approximately 700 at a rate of 'low of hydrocarbon and with a. volume of conduit such that K falls within the limits of .t3-1.2 in the formula v .064 V/R -l-T 633 where V vis the volume of the heated portion of the tube in cubic centimeters, lt the rate of flow of material into the tube in grains per minuta T the temperature of the interior of the tube at the lniddle point in degrees centigrade, and K thc parameter derived therefrom.

8. A process for making ArCH CH2 where Ar represents aryl which comprises heating ahydrocarbon having the general formula ArCHzCl-l, to a temperature ot' approximately -1-50O (1 -700 C., and ipartially decomposing the hydrocarbon lo forni a coniporirind having the general formula ArCl-I 0. A processl for making ArCH: CHJ where Ar represents aryl -which comprises passing a stream of an aromatic hydrocarbon having the formula UCI-12CH, through a conduit heated to a temperature of approximately 450 to a proximately "1'00J C. and splitting off hy rogen therefrom to form a compound having the formula ArCH: CH2.

10. A process for making ArCI-LCH,

recovering where Ar represents aryl which comprises passing a stream` of an aromatic Ihlydro- 4carbon having the formula ArC ZCH,

through a conduit heated to a temperature of approximately 450 C. toapproximatel'y 700 C., collecting a mixture containing a substance havin" the formula ArCH CH2, tarry matter and unchangedArCH2CH3, and recovering the substance ArCH: CH2 therefrom.

11. A process for making styrol which comprises passing a stream of an aromatic hydrocarbon having the formula CsHm through a conduit heated to a temperature of approximately 450 C. to approximately 700 C. and liberating hydrogen from the aromatic hydrocarbon to form styrol.

12. hprocesserfor making :any1-o1 which comprises passing a stream of ethyl benzol through a conduit heated to a temperature of approximately 450"- C. to approximately 700 C., and splitting off hydrogen from the' ethyl benzol to form styrol.

where V is the volume of the heated'portion of the tube in cubic centimeters, R the rate of How of material into the tube in grams per minute, T the temperature of the interior of the tube-at the middle point in degrees centigrade, and -K the parameter detherefrom.

Signed at New York, New York, this 30 day of April, 1924.

IWAN osTRoMIsLENsKY. Mouais G. SHEPARD.

carbon aromatic hydrocarbon to forni styrol.

12. .k .processfor making -styi'ol .which comprises passing a stream of ethyl benzol through a conduit heated to a temperature of approximately 450f C. to approximately 700 C., and splitting ofl' hydrogen from the ethyl beiizol to form st vrol.

13. process for making styrol which comprises passing a stream of vaporized ethyl benzol through a conduit heated to a temperature of approximately 700 C: at a rate of How of hydrocarbon and with a volume of conduit such that K falls within the limits .S4-1.2 in the formula .064 V/R+T where V is the volume of the heated portion of the tube in cubic centimeters, R the rate of flow of material into the tube in grams` per minute, T the temperature of the interior of the tiibeat the liiiddlc point in degrees centigrade, and K the parameter dcriT'ed therefrom.

Signed at New York, New York, this 30 day of April, 1924.

IWAN OSTROMISLENSKY. MORRIS G. SHEPARD.

Certificate of Correction.

, It is hereby certified that in Letters Patent No. 1.541,17 5,

anted June 9, 1925,

upon the application of Iwan Ostroinislensky and Morris G. S epard, of New York 1*.. Y., for an im rovement in Processes for Producing Styrol and its Homologues from Aromatic ydrocarbons, an error appears in the rinted s ilication requiring correction as follows: Page 3, in the hrst column o the tab e under the letter heading I, strike out the word st rol and insert the saine in the second column of the table opposite the same heat ing I formulae and insert instead saine page, line 108, strike out the and that the said Letters Patent should be read with this correction therein that tliewsa'me may conform to the record of the case in the Patent Office.

bigned andsealed this 22d day of June, A. D. 1926.

[sinn] M. J. MOORE, Acting (lommzsaioner of Patents.

Certificate of Correction.

It is hereby certified that in Letters Patent No. 1,541,175, granted June 9, 1925, upon the application of Iwan Ustromislensky and Morris G. Shepard, of New York, N. Y., for an im rovement in Processes for Producing Styrol and its Homologues from Aromatic ydrocarbons, an error appears in the printed s cifcation requiring correction as follows: Page 3, in the hrs-st column of the tab e, under the letter heading I, strike out the word st ro and insert the suine in the second column of the table o posite the same hea( ing I same page, line 108, strike out the formula: and insert instead and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Oice.

Signed and sealed this 22d day of June, A. D. 1926.

[SEAL] M. J. MOORE,

Acting ('ommsm'oner of Patents.

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