US1844900A - High carbon pitch compositions - Google Patents

Description

Feb. 9, 1932. s. P. MILLER 1,844,900

HIGH CARBON FITCH COMPOSITIONS Filed Dec. 29. 1927 3 Sheets-Sheet l Feb. 9, 1932. s. P, MILLER 138445900 umu CARBON P11-ca couros'lnons. y

Fild Dec. 129. `1927 K s sneets-sneet 2 E ge f:

- i INVENTOR BY @awww-Jl WMI/Lam. ATTORNEYS Feb. 9, 1932. s. P. MILLER HIGH CARBON FITCH COMPOSITIONS Filed Deo. 29. 1927 3 Sheetsheet 3 INVENTOR @f6/Ww@ Wd/L Y gama/j AT TORNEYS Patented Feb. 9.,

UNITED STATES PATENT orrlcs STUART PBMELEE' MIILI'JIIEB.,v OF'ENGLEWOOD, NEW JERSEY, SSIGNB T0 THE `IBARREl". COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY HIGH CARBON' FITCH COHPOSITIONS Application med December 29, 1927. Serial No. 243,808.

This invention relates to new pitch com.

positions. The invention relates Aparticularly to pitch compositions of regulated high .carbon content.

In the ordinary operation of by-product coke oven and gas retort plants, the coal distillation gases are cooled to separate tar therefrom andthe tar is shipped to tar distillation plants for distillation. The pitches 1o produced from ordinary coke oven tar have too low a free carbon content to make them available for certain purposes. Pitches containing a high free carbon content are obtained ordinarily from the distillation of l5 gas retort tars, articularly horizontal gas retort tars, or t e admixture of such tars with coke oven tar and the distillation of the mixture. So also, pitches produced from gas retort tars alone may not have the proper 2o carbon content and other properties.

According to the present invention, thel the tar and p1tch, I use these terms in their ordinary meaning to include not only elemental or molecular carbon but also'those constituents which remain as insoluble residue on digestion of the tar or pitch with benzol or similar solvent. It may include certain inorganic impurities as well as insoluble hydrocarbons of high molecular weight.

In my companion application, Serial No 243,307 I have described the production of new high carbon pitches at coke oven or collecting the gases from near the end'of the coltingperiod,coolin the gases to separate high carbon tar there om, and distilling the high carbon tar to produce new hi h carbon 5@ lpitches. The present invention pr uces new other coal distillation plants byseparately' products of a composite and somewhat different character. The new high carbon pitches produced in accordance with said companion application can advantageously be employed according to the present invention in producing the new composite pitchl products.

In my companion application, Serial No. 243,305 I have described the production of low carbon pitches by separately collecting the gases from the early period of the coking operation, cooling the gases to separate a low carbon tar therefrom, and distilling such tar to .produce low carbon pitches; and in my companion application, Serial No. 243,306. I have described the blending of such pitches with tar to give new compositepitch products. The productionof theV new products 0i. such applications,y can if desired, be combined with the production of the products of the present invention; although the present invention is not limited to operations which it is so combined with the processes and the production of the companion applications.

In the practice of the present invention, I provide for the separate collecting of the products of such coke oven or other coal distillation gases given olf during the later portion of the coking operation, when the gases are lower in tar content, and when the tar content ofthe gases is a higher carbon tar than during the earlier period of the coking operation. These gases with their high carbon content are cooled to separatetherefrom a high carbon tar, which tar is subjected to distillation orthe production therefrom of a high carbon pitch. These operations can be carried out in accordance with the process and to produce the product described in m companion'application, Serial No. 243,30; but the distillation of the tar will be carried to such a point that a relatively high melting point pitch will be produced of high carbon content, 'which pitch then blend with additional tar or lower melting point pitch to produce new composite products.

The present invention is of articular value for the production of high car on pitch prodv ucts of relatively low melting point and of higher carbon content than can be obtained by the ordinary distillation of coal tar. For example, for certain purposes such as roadmaking purposes, relatively low melting point pitches are required having a melting point around 105 to 110 F. and containing a carbon content around 12 to 15%. Such pitches ordinarily require the addition of high carbon gas retort tar to coke oven tar before distillation. Such pitches can readily be produced according to the present invention by subjecting the high carbon tar from the coke oven gases to distillation to produce a high carbon pitch of high melting point and then blending this pitch in proper proportion with tar or soft pitch, either Without or with further distillation of the mixture to remove additional oils therefrom. For example, the high carbon pitches can be produced of melting point around 145 to 165 F., or even around 225 or 250 or even 300 F., or higher, and such high carbon pitches can then be blended with tar or sot pitch to produce the new composite products.

The distillation of the high carbon tar and the production of the high carbon pitch which is to be blended with the additional tar or soft pitch is advantageously carried out at the coke oven or gas retort plant by bringing the tar into direct and intimate contact with the hot coal distillation gases; and this operation can be carried out in a continuous manner, with the continuous production of the high carbon pitch, and the continuous blending of such pitch with the tar or soit pitch to pro uce the new composite products in a continuous manner.

In the production of the' new product at coal distillation plants, for example, at coke oven plants, I provide a plurality of collector mains, one for the gases from near the end of the coking operation from which the high carbon tar is to be separated, and another for the gases from the earlier period of the cok-k ing operation from which a lower carbon tar is separated; and I provide in addition separate condensing systems for the further condensation of light tar or tarry oil from the respective gases. The heavy tars from the collector mains and the lighter tars or ytarry oils from the condensers are kept separate. The high carbon tars from the collector main and condensers may be combined together for distillation yor distilled separately. Similarly, the lower carbon tars from the collector main and condensers may, if desired, be subjected to distillation either in admixture or separately to produce low carbonpitches, although such low carbon tars can be utilized for other purposes.

In addition to such separate condensing and collecting systems and apparatus for keeping separate the respective tars, I provide a distillation apparatus for distilling the high carbon tar or tars together or separately, which distillation apparatus is advantageously one in which the distillation is eifected by direct and intimate contact with hot coal distillation gases. This can be carried out in various ways, such as by the provision of a still or short collector main into which the tar to. be distilled is introduced and into which the gases from a selected number of ovens are introduced at a high temperature, and in which the tar is brought into intimate contact with the hot gases, as by spraying or atomizing the tar into the gases by means of spray nozzles or mechanical agitating devices such as rotary discs or rotary rolls, etc., rotating at a high rate of speed to atomize the tar and bring it into intimate contact with all parts of the gas in the still. By introducing the high carbon tar continuously and withdrawing the high carbon pitch' continuously, the high carbon pitch is available in a highly heated state for lblending with the tar or soi't pitch and this blending can advantageously be carried out with utilization oi the heat of the hot pitch for assisting in the blending operations and for heating and in some cases if desired, for distilling the lighter oils from the tar blended therewith.

The character and particularly the melting point of the pitch produced may be varied by varying the extent to which the distillation is carried, but the distillation will in most cases be carried suiiiciently to produce a pitch of relatively high melting point, as compared with the melting point of the desired pitch composition. The maximum melting point will in some cases be limited by the free carbon content of the pitch, since a veryhigh carbon content pitch is in general more difficult to handle and to circulate and to keep iiuid than a pitch of lower free carbon content but of corresponding melting point. In general, however, the melting point of the high can bon pitch produced will be determined by the desired character of the pitch composition resulting from the blending of the high carbon pitch with tar or with a lower melting point pitch. For example, a pitch of a melting point of about 105 to 110 F., to be used for road construction can be made by blending pitch of not higher than 165 F. melting point with the required amount of tar to reduce the melting point to 105 to 110 F. However, it is readily possible to produce high carbon pitches of melting points up to 300 F. and in some cases up to 400 F. or higher. Such distillation gives a high yield of oils of high specific gravity and some of them of high boiling point. Some increase in carbon content may take place during the distillation of the high carbon tar by means of the hot coke oven gases, but this increase will be much less than when the high carbon tars are distilled in ordinary externally heated tar stills. The carbon content ol' the pitch can be regulated and controlled to a greater tion of the coke ovens during which the gases of 3o the collector main in W are collected for the separation of tar therefrom, therebyrecovering tars of higher or less high carbon content, from which pitches of somewhat varying high carbon content can be produced.

rlhe tar which is blended with the high carbon pitch, acconding to the present invention, may be varicdin accordance with the character of the composite pitch desired. For some purposes, the tar to be blended with the high carbon pitch may itself be high carbon tar such as is separated from the leangase's near the end of the coking operation. Blends of such tars With the high melting point and high carbon pitches will give compositepitch products of intermediate melting point but of relatively 'high carbon content. For some purposes, a much lower carbon content of the blended mixture is suthcient, and, in such cases, the tar blended with the high carbon pitch maybe ordinary coke oven tar with its normal carbon content, that is, colte oven tar such as is obtained when the total tar from the various ovens is collected together. ln somecases, the low carbon tars produced from the rich gases given oil during the early period the colring operation nia-y be blended to a greater or less extent to regulate and control the carbon content of the blended product.

The separate collection of high and low carbon tars at the coke oven plant and the separate distillation of the high carbon tar to produce high carbon pitch gives 1arious products at the colte oven plant for blending in an undistilled condition with the high carbon pitch.' F or example, theheavy tar from hich the high carbon tar is collected, may be employed for blending purposes, and its relatively lower oil content makes it particularly' valuable for that purpose. So'V also, Where ordinary heavy tar from the collector main in which all of the tar from the ovens is collected together, is available, this may be blended with' the high carbon pitch to form new composite products. The tar which is blended with the 'high carbon pitch may itself be subjected yto an initial or partial distillation to dehyrate it or to free it from lower boiling oils, although inl some cases the raw tar may be employed without such distillation or dehyration. `By reguvlatiirigthe lamount of the'tar and pitch blended with each other and the carbon content of the pitch and the tar, composite products of intermediate carbon content and` point can be produced, and this canbe regulated by regulating and controlling the character of the individual products'which are blended with each other. I do not, however, exclude the blending of tars other than coke oven tars with the new high carbon pitches,

since in some cases tar from other sources, may be employed.

-melting The products of the blending'of diierent tars,` etc., with the high melting point high carbon pitches,

pitch with tar is accomplished preferably by introducing continuous streams; of the hot thinly iluid materials to be blended into a suitable receptacle, the streams being directed so that they vflow together and thus immediately produce `a uniform blended product. Such operation is particularly desirable if the tar which is introduced contains Water because the temperature of the pitch may be such as to vaporize the Water immediately together With some of 4the more volatile constituents of the tar,r thus producing a dehydrated product. The vaporizedwater and oil constituents can be withdrawn continuously from the receptacle and the oil can be condensed by the provision of a suitable condenser. The oil can, after separation of Water, be returned to the pitch, if desired. rlhe blended product can likewise be Withdrawn continuously from the receptacle and deliyered to suitable storage containers.

As an example of the practice of the invention the gases from the latter portion of the colring period oi a coke oven plant can be cooled in the separate collector main by ammonia liquor or ammonia liquor and tar 4supplied thereto and the separated heavy tar containing a relatively high free carbon Lcontent can be distilled then in a separate distillation main by contact with the hot gases from the ovens to produce a pitch having' a melting point ci, for example, from 165 to 2259 F. or up to 300 F. or higher. To produce a. road-treating' pitch having a melting pointof 'approximately 105 l?, and a free carbon content of around l2 to 15%, the desired high melting point pitch can be blended continuously in the manner described with av suitable proportion of raur tar from the saine plant from other cokeV oven batteries or', with tar from gas retorts or similar coal will differ in characteristics, depending upon the nature of the materials' icoy amount can be determined readily by test 'and the blending can be so conducted as to produce a uniform road-treating pitch having the desired melting point with the proper proportion of free carbon.

In applying the invention at gas retort plants, or With gas retort tars, it is possible to produce new composite pitch products varying with the particular tar employed. Horizontal and inclined gas retort plants, Which give high carbon tars, will give unusually high carbon tars from the gases given oil during the latter part of the gas making operation, and these tars on distillation will ican he blended, "rind to give a products, or re lower carbon carbon tars ration of interdistillation #tent than tr produced lower than, pints, or

give high carbon. pitches v" with additional tar oi' unusually high carbon with lower carbon tai i pitch compositions. m from the later part o mittent vertical r give pitches oi' those obtained fr at such plants, but i that obtained at horl.J even at eolie oven plant various high carbon ,A itches y ing kinds a Wide i composite blended products can be preduceda The invention may a coke oven plants or to re out any considerable ino except for the provision ot lector mains7 separate cc cles and the dist rat-us. The op the recovery oi v... not been available heretoio s L ants,ivitli i vthereof re as the result or Coke oven or gas retort operation.

The production oi the new compositions will be further des""bed in connection with the accompanying dran/'ings ii ivhich- Fig. l is a plan viert ot a portion ot a colic oven battery;

Fig. 2 is a cross-sectional vier? oli one of the collector mains;

Figs. 5 and a are enlarged sectional views of the short collector mani; n l

Figs. 5y and G are details n section of the blending apparatus.

Referring to the drawings, 5 indicates a battery oi' ovens Which are connected by uptake pipes and goose-necks G to rali/e boxes 7 which communicate with collector mains 8 and 9. Valves 10 are arranged the valve boxes to permit the direction of the hot coke oven gases into one or the other of the collector mains, depending upon the stage of the coal distillation operation in the particular oven to which the valve box is connected. Thus. by operating the Valves rich and lean gases from the several ovens ot the battery can be collected separately in the collector mains wherein they are cooled to the desired extent by ammonia liquor introduced through spray nozzles ll which are supplied through a pump 12 and pipe 13 from. a source of ammonia liquor such as a tank 15.'

From the collector mains the gases carrying oil vapors and partially condensed tarry constituents are delivered through cross-over mains 16 and 17` to condensers 18 and 19 in which the gases are further cooledto separate the tarry oil constituents1 The oil, together with ammonia liquor, can be Withdrawn through pipes 20 and 2l and delivered to decanters 22 and 23 wherein. the ammonia liquor is -separated Jfrom 'the tarry oil. The tarrv oil can be delivered to suitable storage receptacles and the ammonia liquor can be returned if desired for further use as a cooling medium either in the collector mains or in the condensers. The gases escaping from the condensers are delivered through pipes 2li and 25 to exhausters 26 and 26 and thence to equipment (not shown) for the separation of ammonia, light oils, etc.

The tar which separates in the collector mains can be Withdrawn through pipes 27 and 28 to decanters 29 and 30, in Which ammonia liquor is separated While the tar is stored in tanks. rlhe ammonia liquor may be returned to the collector mains for cooling or may be utilized to recover ammonia therefrom. rl`he tar from the lean gas main contains a relatively high. proportion of free carbon and this tar is subjected to distillation in a suitable still such, for example, as a short collector main or still 31 which is dis-- posed preferably at the' rear of the ovens and is connected to a plurality of ovens so that het coal distillation gases pass continuously through the short collector main or still. The tar to be distilled may be introduced to the short collector main or still at one end through pipe 32 by pump 33. The collector main or still 3l is filled with a cylinder 84 adapted to be rotated at a high rate of speed. by electric motor 35. The cylinder dips into the body of tar and pitch inthe bottom oi collector main or still 31 and atoinizes the tar andpitch, in the` form ot a finely disseminated sp1-ay, into the gases passing through the collector main or Astill 3l. The are thus effectively scrubbed by the tar and pitch. In thus mingling with the hot gases the tar is distilled to produce pitch'ivnich is Withdrawn continuously at 36 and the volatile constituents are separated and join the gases which run through settling tower 1G in which the tar spray and globules and other entrained matter settle out of the scrubbed gases and are returned to the collector main or still 8l. The tower 46 may if desired contain baffles or packing. The gases may be Withdrawn continuously through a pipe 37 and delivered to a condenser 38 located at any suitable place, Wheein the oil constituents can be separated from the gases. Thereafterl the gases may be delivered through a pipe 39 to an exhauster and mingled with the remaining gases from the ovens of the battery.

The pitch produced is withdrawn continuously at 36 into receiver 47 from which it is conveyed by pipe 40 and delivered to the blending apparatus ll comprising a chamber into which. the pitch, still at high temperature, is introduced. The tar or other material to be blended with the pitch is similarly introduced through a pipe 42, the two pipes being directed so that the streams are mingled as they enter the chamber as shown in Fig. 6. The tar and pitch thus intimately mingle and blend to produce a product having the delighter oil constituents will be vaporized immediately upon contact between the tar and pitch. The vapor can be withdrawn as it is released vthrough a pipe 44 and delivered to Y a condenser 45 wherein it is cooled. The oil thus recovered can beI mixed with oil obtained by the cooling of other gases from the system, or can be returned to the pitch in I The mixing of the hot high carbon pitch,

while at a high temperature, with the tar in the mixing chamber 4l, preferably takes place continuously, and any ioaming'due to heating of coal ta'r containing water by the hot pitch is readily taken care of. The continuous ow of the tar and the pitch causes the blending of the pitch and tar continuously to give a resulting composite blended product which is still suiiiciently hot to be thinly fluid and to run from the apparatus, although the blended product on cooling may be e Vsolid product oi higher or lower melting point. VThe tar which is thus added to and blended with the hot high carbon pitch may itself be preheated and dehydrated or partly distilled to remove part vof the light oils therefrom, although such preheating and 4dehydrationmay in some cases be omitted and raw wet tar employed. The tar may, as above pointed out, be itself a high carbon tar,

or a low carbon tar, or an ordinary normal carbon tar, depending upon the carbon content and other properties Voie the blended product. rlhe tar need not he a coke oven vertical retort tar, low temperature tar, etc.

rl"his production of the new blended product is carried out at a coke oven plant, with elimination ot' the transportation of coke oven tar to tar distillation plants or of high carbon gas retort tar to tar distillation plants, and with the production of the new composite product-by distilling only a limited amount of high carbon tar which, however,

.is distilled to give a large yield .of oils therefrom of high specific gravity ,andf relatively high boiling point; A

The new composite pitch products will be l ,made up of the tar utilized in producing them and of the high carbon pitch blended therewith to form a homogeneous product.

These composite l productswill diiier in char-V acter from pitches of the same melting point produced by direct distillation of the high carbon tar.

The process of producing the newfcompof site products diiers from the process of proi ducing the new high carbon pitches of my companion application, Serial No. 243,307, in that it does not rely upon distillation of all of the tar employed to produce the pitch desired, but subjects only part of the high tional undistilled tar to produce the new composite products. The production of' the 'new compositions `involves the distillation of less tar, but distillation to 'a much higher melting point pitch, as compared with the productionof the compositions of said companion application when such pitches are of intermediate melting point.

In its broader aspects, production of the new compositions is not limited to the continuous distillation of the tar to produce the high carbon pitch, nor is it limited to the continuous blending of the hot high carbon pitch as produced with the tar, although the process is advantageously carriedl out in a continuous manner with continuous distillation ofthe .tar and continuous production of pitch and with continuous blending of the hot high carbon pitch with the raw tar, or with specially treated tar, to produce the new composite pitch products.

While production of the new pitch cornpositions has been more particularly described in connection with coke oven operation and the production of coke oven tar pitches, it is applicable to other coal distillation plants and ters, such as certain gas retort plants and ters, to produce new conposite pitch products.

l cleirn l. New composite blended pitch composi- A Y tions, comprising high free carbon pitch of tar, hut may he water gas tar, gas house tar,

high melting point blended with a substantial amount of coal tar, said coal tar including low boilingI constituents not present in a straight distillation pitch of the same melting point as the composite blended pitch composition, the high carbon pitch .resulting from the distillation of high carbon tar produced from colte oven orother coal distillation `gases during the latter period of the Coking of coal in colte ovens or other distillationy of high carbon colte oven tar recovered fromcoke oven gases during the latter period of thecolring of charges of'coal in coke ovens, the coke oven tar compr1s1ng lower boiling constituents not present in a pitch produced by the strei ht distillation of th'e coke oven tar to pito of the same melting point as the composite blenced pitch 5 composition.

In testimony whereof I ax my signature.

STUART PARMELEE MILLER.

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