US1191916A - Process of and apparatus for chlorinating. - Google Patents

Description

B. T. BROOKS, H. ESSEX & D. F. SMITH.

PROCESS OF AND APPARATUS FOR CHLORINATING.

APPLICATION FILED DEC. 8. I9l5.

Patented July 18, 1916.

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BENJAMIN T. BROOKS, HARRY ESSEX, AND DILLON'F. SMITH, 0F PITTSBURGH, PENN- SYLVANIA, ASSIGNOESTO GULF BEFINING COMPANY, OF PITTSBURGH, PENNSYL- VANIA, A. COREORATION 0E TEXAS.

PROCESS OF AND APPARATUS CHLORINATING.

Specification of Letters Eitent.

Patented July 18, 191%.

To all whom it may concern:

Be it known that we, BENJAMIN T. Baoons, HARRE; Essex, and DILLON F. SMITH, citizens of the United States, and residents of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Processes of and Apparatus for Chlorinating, of which the following is a specification.

This invention relates to processes of and apparatus for chlorinating; and it comprises a method of chlorinating liquid hydrocarbons, such as gasolene, and petroleum oils, benzol, toluol, etc., wherein a temperature controlled body of such liquid hydrocarbon is treated with chlorin under the influence of actinic light, the chlorin being introduced at a point in the liquid body remote from the point at which the rays of actinic light enter such body, as by illuminating a body of liquid hydrocarbon from the top while introducing chlorin gas at the bottom; and it also comprises a chlorinating apparatus particularly adapted for the chlorination of light and volatile oils and having a chamber of suitable resistant and opaque material, provided with means for introducing chlorin at the lower end, means for introducing or producing actinic light at the upper end, means for varying the intensity of such light, means for controlling the temperature of the chamber and means for collecting volatile and gaseous products formed in the action; all as more fully hereinafter set forth and as claimed.

1n the chlorination of hydrocarbons, as is well known, the action, in the absence of facilitating catalysts, depends largely upon the illumination. For some unknown reason, light causes chlorin to enter into substitutive reaction with the various hydrocarbons with the production of chlorin substitution products and H01. But the trouble with the practical application of this fact is that the action is apt to be uncontrollable. It is, for example, very diflicult to chlorinate any hydrocarbon, whether liquid or gaseous, to produce. monochlor products (that is, products containing only one chlorin atom in the molecule) to the practical exclusion of di, tri, etc., compounds. Similarly, it is difiicult to produce the dichlor compounds to the exclusion of the high r chl rinated compounds. Further, it is often diflicult to prevent the reaction becoming so violent as in some cases to lead to the deposition of carbon or in the presence of sufficient chlorin, to explosion. Direct chlorination is there- 'fore not as muchused as the value of the products which may be obtained thereby would warrant. It is too difficult to control the reaction. For this reason, where halogen substitution products are wanted for chemical purposes as a rule, another halogen, bromln, is used and bromin compounds are made, bromination being less difficult to control than chlorination.

The exact nature of the action which light exerts upon chlorin, rendering it more prone to combination, is not known; but it is known that the rays of the spectrum which produce this action lie toward the ultra violet end; and it is also known that the rays capable of activating chlorin are absorbed by chlorin. Taking advantage of these facts, we have devised a simple, cheap and ready method of controllably chlorinating liquid hydrocarbons and other liquid bodies capable of dissolving chlorin and of reacting therewith under the influence of light. It may, for example, be used for converting liquid hydrocarbons into the monochlor derivatives, for converting the monochlor derivatives into dichlor derivatives, and so on. In this novel method we simply irradiate one end of a body of liquid hydrocarbon or other liquid to be treated from a source of actinic rays, While introducing chlorin at the other end, and causing it, or the solution it produces in dissolving, to approach the illuminated end. In practice, the illuminated end of the body of liquid, for obvious reasons, is usually the top, while the chlorin is introduced as gas at the bottom. Presuming a body of gasolene, or a fraction obtained by distilling gasolene, to be chlorinated, the oil is placed in an opaque vessel having means for controllable illumination at its end; such means being, for example, a mercury vapor lamp, or a nitrogen-filled tungsten lamp. The lamp is best provided with a rheostat whereby the amount of light emitted may be controlled. At the bottom of the container we provide means for introducing gaseous chlorin. Means are also advantageously provided for agitating and circulating the liquid in any desired degree. Artificial the downwardly passing. light soon estab-. lish a sort of balance; there is established a zone of maximum reaction somewhere between the top and bottom. If the liquid be circulated, the action is somewhat different, since the circulating means, which of course should be controllably driven, will bring a greater or less amount of chlorin-containing liquid under the influence of the light rays; an amount which of course canbe nicely controlled and with it the progress of the reaction. Inso doing the concentrationof the dissolved chlorin in the liquid in the illuminated zone is always small; or, stated in another way, in the zone where. action is taking place there is always a large excess of hydrocarbon over chlorin- This much con-r duces to smoothness of action in forming.

nionochlor derivatives. But with artificial circulation within limits the reaction is selfcontrolling; that is for a given amount of light and a given rate of introduction of chlorimthe total actionper minute will tend to be uniform. This is for the reason that the less the amount of dissolved clilorin, the

further the chorin-afi'ecting rays can penetrate and vice-versa.

The chlorin dissolving in the oil colors it yellow and as the chlorindisappea-rs from solution by reaction with the liquid, the color of the liquid also disappears. With this disappearance the striking down or absorbing of active rays also disappears; that is the active rays pass through the uncolored oil, but not through the colored.

Any suitable container capable of Withstanding the action of chlorin and of the particular substances to be chlorinated may be employed. Stoneware or interiorly enameled steel vessels may be used. The particular material of the vessel to be used isnot important so long as it is resistant to chemical action and is opaque. The entrance of light into the treating vessel other than the controllable actinic light provided for should be avoided.

r In practice, the reaction chamber should he provided with means of adjusting the temperature, such means ordinarily being cooling means, although in some instances heating may be necessary. The use of temperature controlling means is particularly important in chlorinating aromatic compounds, such as benzene, toluene, etc. As is well known, in the case of toluene and the xylenes, the temperature at the time of chlorination has a profound influence on the location of the chlorin atom entering the If the liquid is not circu molecule: whether it enters the nucleus or a sidecha-in. The reaction vessel, if of small size, may be jacketed with a temperaturecontrolling jacket. If oflarger size, it may i be provided with heatingor cooling coils of suitable material. The reaction chamber should ordinarily be provided with a reflux condenser and particularly Where the operation is caried onin the heat. As reactions of substitution, such as ai'ehere involved,

produce HCl as a by-product, means should be provided fOI'TGIIIOVlDg and collectingthe hydrochloric acid formed.

In the accompanying illustratiomwe have shown, more or less diagrammatically,certain embodiments of apparatus elements within our invention anduseful in the performance of the described process.

In this showing, Figure 1 is a central vertical section with certain parts in elevation,

downwardalong line 22 of Fig. 1.

Inthisshowing element 1 is a container ofanys utable material resistant to chlorin, .iIC1dS,.01-lS, etc. Enamelediron,stoneware,

etc., may be iised.- At a pointtoward the .may circulate. This coil as shown (see Fig. 2) is located at one side of the vessel to be out of the way of certain other elements.

Also depending from the cover is lamp 6 fed by wires 7 and controlled by rlieostat 8. This lamp (see Fig. 2), is best located on the opposite side of the vessel to the cooling coils. Next the cooling coils and below them is chlorin introduction pipe 9 carrying a number of minute perforations 10.

This pipe passes upwardly through the cover. Centrally located in the reaction vessel is stirring means 11 which may be a single propeller wheel of any suitable rcsistant material. Also passing through the cover of the vessel is a reflux condenser 12, provided with cooling jacket 13. Above the cooling jacket the pipe is prolonged as conduit 14 into which enters a branch 15 for introducing water to the discharged vapors.

85 and Fig. 2 is a horizontal section; looking any time to time through 21. The oily layer may be returned to reaction vessel through 22. Uncondensed vapors and gases leave this chamber through 23 and may receive another addition of water at 24:, be cooled in 25 by means of cooling acket 26 and condensed materials discharged into tank 27,-

where aqueous acid and oil separate as layers 28 and 29, respectively. Acid may be discharged at 30 and oil returned to the first mentioned receptacle through 31. .As

many of these cooling and washing'devices may be used in train as may be desired. Thermometer 32 may be used to indicate the temperature'in the reaction chamber.

In the employment of the above described apparatus, and in performing the stated process, presuming the material to be chlorinated is a gasolene fraction, as inmaking.

mixed butyl, pentyl, hexyl, etc., chlorids for the manufacture of artificial amyl acetate,' chamber 1 may be filled with a l1qu1d gasolene fraction. In making artificial amyl acetate, this fraction will ordinarily be the portion of commercial gasolene distill ng between 25 and 45 C. The chamber being full of the liquid, chlorin is introduced through inlet 10, passing into the liquid as minute bubbles.- As these pass upward they but not Very greatly so in passing throughthe upper layers of chlorin-free liquid. But

as they pass downwardly, they pass into,

layers of liquid containing dissolved chlorin and colored thereby. This dissolved chlorin is caused to disappear by reaction with the gasolene which holds it in solution. The intensity of the actinic rays passing downwardly is diminished in proportion to the work which they do in passing through this first weak solution of chlorin; and to an extent proportionally to the amount of chlorin in the solution and to the depth of the solution through which they pass. The amount of light therefore penetrating to the lower layers of gasolene containing greater amounts of chlorin is automatically diminished to a degree permitting only a gentle action. Practically, the maximum action of the light and of the chlorin take place in a zone of the liquid containing only the amount of chlorin which will permit a free reaction. But at this point the gasolene is,

i of course, in large excess; and the tendency of the action of the light is therefore merely heat. observing the color of the liquid at an interto make the monochlor products; and not to induce further chlorination of mono compounds already produced. The introduction of chlorin and the action of the light may be continued until the liquid in the container s chlorinated to the desired degree.- In

working with the stated gasolene fraction, we ordinarily do not\ carry the chlorination beyond where, say, 20 per cent. of the material is converted into mono chlorids. 'VVe prefer at this time to interrupt the opera-.

tion, separate the unchanged oil from the chlorids formed by means of fractional disallowed to flow continuously into one or more stills (not shown) where it may be distilled. As the chlorinated compounds are of higher boiling point than the original gasolene it is easy to recover the unchanged gasolene in this manner. The gasolene so recovered together with fresh gasolene may be fed into the chlorinating apparatus through inlet 41.

If dichlorids are to be produced, the process is exactly the same, save that inlieu of charging the container with hydrocarbon, it is charged with mono-chlorids. Here again itis desirable to carry the action forward so that only a fraction of the material is chlorinated and then interrupt the operation to separate the dichlorids from the unchanged mono chlorid. In the same manner dichlorids may be converted into .trichlorids and so on.

We regard our invention as generally applicable to the chlorination of any liquid capable of absorbing chlorin in the dark by simple solution to give a chlorin-colored solution capable of absorbing actinic rays with the production, under the influence of such actinic rays, of chlorination products. If the material to be chlorinated be not naturally a liquid, it may of course be melted or dissolved, as by using C01 For example, paraflin' may be melted-and chlorinated as described.

' In chlorinating a gasolene fraction in the manner described, the intensity of the light used and the quantity of chlorin may be adjusted in accordance with observation of the temperature indicated by thermometer 32. The chlorinating reaction is one evolving Or the reaction may be followed by mediate point through windows 2. As stated, solution of chlorin in the liquid colors it yellow and the point at which the chlorin disappears can thereforebe readily seen.

In chlorinating the described gasolene fraction, there is more or less evolution of HCl gas and this tends to carry forward vapors of the gasolene from the apparatus. These gasolene vapors may be condensedand returned through reflux cooler 12. Gas passing beyond the reflux will be largely HCl. By introducing a little water or water vapor through 15 and then passing the mixture through cooler 16, the HCl is absorbed or condensed as a solution of any desired strength. This solution may be collected in receiver 18, where it forms a heavy layer underlying an oily layer of unchanged gasolene. This layer of hydrochloric acid may be tapped off through 21, while'the oily supernatant layer may be returned to the treatment chamber through 22.

While we have hereinbefore specifically mentioned chlorin as the halogen with which we operate, we wish it to be understood that the same method may be used in the case of bromin where bromm substitution products are desired. In using bromin 1n lieu of chlorin, the bromin is introduced at the bottom of the body of liquid in the same manner as has been described for chlorin; and the action is otherwise similar.

What We claim is 1. The process of chlorinating organic materials wherein a liquid body of such material is exposed to irradiation at one end by a source of actinic light while chlorin is introduced at the other end in such manner as to pass toward the illuminated end.

2. The process of chlorinating organic materials which comprises placing a body of such material in liquid form in an opaque container, irradiating the upper end of the body of liquid by a source of actinic light and passing chlorin into the lower end of the container.

3. The process of chlorinating gasolene fractions which comprises placing a body of such gasolene fractions in an opaque container, irradiating the upper end of the body of such gasolene fraction by a source of actinic light and passing chlorin into the lower end of the container.

4. In the chlorination of organic liquids the process which comprises establishing and maintaining a body of such liquid, illuminating one end by means of actinic light, in-

troducing chlorin at the other end and producing. a progressive movement of such liquid from the point of chlorin introduction to the point of illumination.

5. In the chlorination of organic liquids the process which comprises establishing and maintaining a vertical body of such liquid in .a suitable opaque container, illuminating the upper end of the body by actinic light, introducing chlorin gas into the lower end and stirring in such manner as to bring chlorin solution upwardly toward the light.

6. In the chlorination of volatile organic liquids with recovery of by-products, the process which comprises establishing and maintaining a vertical body of such li uid, illuminating the upper end by actinic light, introducing chlorin at the lower end while stirring to bring the chlorin solution toward the light, removing the vapors from the upper end, adding a controlled amount of water to such vapors, cooling such vapors to produce condensed liquid and hydrochloric acid solution, separating and removing the hydrochloric acid solution and returning condensed volatile liquid to .the reaction chamber.

7. In the chlorination of volatile organic liquids with production of by-products, the process which comprises introducing chlorin into a temperature-controlled body of such liquid under conditions producing a substitutive action, removing gases and vapors from the body of liquid, adding a controlled amount of water to such gases and vapors, cooling the gases and vapors to produce a condensate of aqueous hydrochloric acid and of such volatile body, separating the hydrochloric acid and returning the vol ther treatment.

8. In the chlorination of petroleum hydrocarbons to produce monochlor substitution products, the process which comprises slowly introducing chlorin into a body of such petroleum hydrocarbon, locally illuminating the body of hydrocarbon at a point removed from the point of chlorin introduction, stirring to produce a limited chlorination at a point between the point of chlorin introduction and the point of illumination, and ceasing the operation at a time when about 20 per cent. of the material has been chlorinated.

9. In the manufacture of materials for the production of amyl acetate, the process which comprises chlorinating a gasolene fraction distilling between about 25 and 45 C. in an opaque chamber by means of chlorin introduced at one point in said chamber and actinic light introduced at another, the liquid being stirred during such introduction to bring the chlorin solution progressively toward the light, and the operation being interrupted when about 20 per cent. of such liquid is chlorinated.

10. In the manufacture of materials for the production of amyl acetate, the process which comprises chlorinating a gasolene fraction distilling between about 25 and 45 C. in an opaque chamber by means of chlorin introduced at one point in said chamber and actinic light introduced at another, the liquid being stirred during such introduction to bring the chlorin solution progressively toward the light, interrupting the operation when about 20 per cent. of such liquid is chlorinated, separating the chloriatile body to the reaction chamber for furnated material from the unchanged gasolene fraction and returning the latter for further chlorination.

11. In the chlorination of organic liquids for the production of definite derivatives, the process which comprises placing such a liquid in an opaque chamber, illuminating one portion of such chamber while introducing chlorin at a point remote from such portion, stirring the liquid to cause the same to circulate between the point of chlorin introduction and'the point of illumination, and interrupting the operation when about 20 per cent. of the material has undergone reaction with such chlorin.

12. In an apparatus for chlorination, an opaque chamber adapted for holding liquid, means for introducing chlorin at one point in such chamber, means for controllably illuminating another point in such chamber from a source of actinic light, and means for circulating the liquid between the point of chlorin introduction and the point of illumination.

13. In apparatus for chlorination, a vertical chamber of opaque material adapted to hold liquid, means for introducing chlorin at the bottom of such chamber, a lamp near the top of such chamber, means'for controlling the illumination afforded by such lamp, and means for stirring liquid in such chamber.

14. In a chlorination apparatus, a chamber of opaque material adapted to contain liquid, temperature controlling means for such chamber, means for introducing chlorin at the base of such chamber, controllable means for illuminating the upper end of such chamber, means for removing vapors from such chamber, means for adding a controlled amount of water to such vapors, means for condensing such vapors and means for separately removing aqueous hydrochloric acid and other liquids formedin such condensation.

In testimony whereof, We affix our signatures hereto.

BENJAMIN T. BROOKS. HARRY ESSEX. DILLON F. SMITH.

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