US1912396A - Production of creosoting compositions, etc. - Google Patents

Description

June 6, 1933. s. P. MILLER PRODUCTION OF CREOSOTING COMPOSITIONS, ETC

3 Sheets-Sheet 1 Filed June 8, 1929 June 6, 1933. s. P.'M1L| ER PRODUCTION 0F GREOSOTING COMPOSITIONS, ETC

3 Sheets-Sheetl 2 Filed June 8.v 1929 INVENTOR www BY 7M ATTORNEY S June 6, 1933. s. P. MILLER PRODUCTION OF CREOSOTING CoMPosITIONs, ETC

Filed June 8, 1929 v3 Sheets-Sheet 3 [am/enfer INVENTOR W7mu 2y I i fm ATTORNEYS Patented June 6, 1933 `UNITED STATES PATENT OFFICE STUART PARCMELEE MILLER, OF ENGLEWOOD, NEW JERSEY, ASSIGNOR TO THE BARRETT COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY PRODUCTION OF CREOSOTINGV COMPOSITIONS, ETC.

Application filed June 8, 1929.

This invention relates to a new and iinproved method of preparing tarry oils, more particularly such tarry oils as may be used for creosoting composition. The invention comprises the method and apparatus for carrying it out.

According to the present invention, hot coke oven gases or gas retort gases from a plurality of ovens or retorts are cooled preferably in two or more stages and the total tar thus produced together with the tar produced by partially cooling the gases from other ovens or retorts is distilled to pitch in the hot coal distillation gases from still other ovens or retorts, and the resulting gases and vapors together with the gases and vapors resulting from partial cooling of the gases above referred to are together cooled to produce a tarry oil. This tarry oil may be employed directly as a substitute for the ordinary creosoting compositions of the type known as coal tar solution. In special cases it may be desirable to eliminate a part or all of the lighter oil from the tarry oils recovered in the process or to add tar or to add distillate oils to the tarry oils before use as creosoting compositions.

In making ordinary coal tar solutions, the greater part of the tar collected from the gases is distilled and the distillate is blended with a relatively small proportion ot' undistilled tar usually in the proportion of 80% of distillate to 20% of tar to make the coal tar solutions of commerce. The distillation of this large amount of tar is expensive and when distilled by the usual methods considerable decomposition of oil takes place during the distillation with resulting loss of valuable oil and corresponding increase in pitch production.

According to the present invention the coke oven or gas retort gases from a plurality of ovens or retorts are partially cooled to remove a portion of the condensable constituents carried by the gases and the resulting gases which still contain condensable constituents together with entrained pitch impurities are blended with gases from other ovens or retorts which have been en- Serial No. 369,499.

riched in condensable constituents by the distillation of tar therein. The taiL used for enriching these gases is the tar resulting from partial cooling' of the first-mentioned gases together with both heavier and lighter tar or tarry oil resulting from complete coolinghof gases from other ovens or retorts which complet-e cooling is usually carried on in two or more stages which results in a heavier tar and one or more tarry oils.

Fresh hot coai distillation gases such as the gases from coke ovens or gas retorts carry impurities from the ovens in finely suspended form known as tar fog. This tar fog comprises pitch, dust, tine particles ot coke, etc. Ordinarily this tar fog persists in the gases and a part of the tar tog is carried over to the condensers and beyond as particles suspended in the gases. Coke oven and retort gases arev ordinarily cooled in two or more stages.

The ovens or retorts of a battery or block are connected with a gas-collecting main and the gases are cooled within this main and a tar, which is a heavy tar, results from this cooling. The gases are then passed to condensers W iere they are subjected to iurther cooling and a tarry oil is recovered from the gases. The heavier tar from the gas-collector mains and the tarry oil trom the condensers comprise the chietl tar products from ordinary coke oven operations, although other tars may be obtained as, for example, the tarry oils from the cross over main of a coke oven battery. Such tar products which are usually of relatively minor quantity7 are ordinarily blended with the heavier tar or the tarry oil and ordinarily the heavy tar and tarry oil are blended to produce the total tar.

The tarry oil from the condensers con.

tains too high a percentage of free carbon to constitute a satisfactory coal tar solution. This free carbon content is due to the considerable amount of tarry and pitchy matter contained in the oil. By distilling tar in the hot gases as contemplated by this invention the condensable vapor content of the gases is increased and the free carbon content of the tarry oil recovered by cooling the gases is correspondingly decreased owing to the enrichment with clean oil vapors.

According to this invention hot coal distillation gases are enriched by the distillation of tar in the hot gases and the resulting gases and vapors which on cooling will yield an oil containing a free carbon content of less than that allowable in creosoting composition are blended with gases not so enriched and which on cooling will yield a tarry oil containing a higher free carbon content than is permissible in coal tar solutions. The mixed gases are cooled to produce a tarry oil of desired intermediate free carbon content.

The distillation of the tar in the hot gases can advantageously be carried out by spraying the tar into the hot gases. rlhis spraying of the gases scrubs the gases at least to some extent and removes entrained impurities carried by the gases. The resulting gases enriched in condensable constituents distilled from the tar, on cooling yield an oil of low free carbon content, and where an intense spray of tar has been employed, the oils obtained by cooling the resulting gases and vapors may be substantially 'free from free carbon.

The distillation of the tar by the hot gases can be so regulated as to produce a pitch with a melting point of 150O or Q00O F., or by carrying the distillation still further a pitch with a melting point oi 350 or even 400 F., or higher can be obtained. It is desirable to carry the distillation of the pitch suliiciently 'liar to distill higher boiling` oils which are desirable in coal tar solutions, which when blended with lower boiling oils such as those present in unenriched coal distillation gases after partial cooling in the collector main, will yield a tarry oil product which will contain only the desired proportion of oil of relatively low boiling range. The complete cooling of such blended gases may yield directly a tarry oil o'l suitable boiling range for creosotingl composition.

According to the preferred method of carrying out this operation, the distillation of the tar is so regulated as to produce a gas enriched in higher boiling constituents and the enriched gas is blended with gases not so enriched which have been subjected to a regulated partial cooling and the gases are blended in such a proportion as to yield on complete cooling a tarry oil with a free carbon content and boiling range which make it suitable for use as a ceosoting composition. Where the gases contain a high percentage of low boiling constituents, a creosoting composition may be produced directly by fractional cooling of the gases. According to this invention a tarry oil is produced which has a limited amount of heavy tar constituents, the amount being such that the oil as a whole and the oil even after distillation to remove any excess of low boiling constituents, will have a suiiiciently low content of so-called free carbon to enable it to be directly employed without the addition of distillate oil for making creosoting compositions. If the content of tarry matter as evidenced by the content of so-called free carbon is not sufficient in the tarry oil recovered, additional tar can be blended therewith.

r1`he invention is illustrated in the accompanying drawings more particularly as applied to the operation of a coke oven plant to produce creosoting compositions directly from the gases, but it is intended and is to be understood that the invention is not limited thereto.

Fig. 1 is a plan view of a coke oven plant equipped for carrying out the invention;

Fig. 2 is an elevation partly in section of the distilling means in Fig. 1;

Fig. 3 is a cross-section on the line 3-3 of Fig. 2;

Fig. 4 is a cross-section on the line 4-4 of Fig. 2; and

Fig. 5 shows in elevation and partly in section the manner in which the main carrying the gases and vapors from the still unites with the ordinary cross-over main.

In the drawings, 5 indicates a coke oven battery the ovens of which are connected to two collector mains 6 and 7. rlhe number of ovens connected to each of the collector mains may vary but may be in the neighborhood of twenty ovens connected with each of the collector mains. The ovens are connected to the collector mains thru the uptake pipes 8. Each of the collector mains is equipped with a center-box indicated by 9 and 10 and cross-over mains 11 and 12 connect these center-boxes with the condensers 13, 14 and 15, 16. A gas main 11 connects the two cross-over mains and by controlling valves in this connecting main and the cross-over mains the amount of gas from each cross-over main drawn into each of the condensers and cooled therein, may be controlled.

The collector main 7 and the connecting by-product recovery system may be operated in the usual manner. The gases are partially cooled within the collector main and pass thru the cross-over main 12 to condensers 15, 16 where the gases are further cooled. rlhe cooling in the collector main may be accomplished by means of sprays of ammonia liquor as is common in the operation of av coke oven battery according to the Semet-Solvay process. The cooling may be carried out with ammonia liquor and tar or wet tar, according to the Koppers system. The drawings show spraying means 17 and 18 connected with a line 19 by which the gases in the uptake pipes and collector main may be sprayed with ammonia. liquor. The tar and ammonia liquor which drain to the center-box 10 are drawn off to the decanter 2O from which ammonia liquor is separately collected in the tank 21 and the tar is collected in 22. Whatever the manner of cooling the gases in the collector main, it is assumed for this illustration that the tar is collected in the tank 22.

The condensers 15, 16 may be of the direct or indirect type. In the drawings they are illustrated as direct condensers in which the gases are sprayed With ammonia liquor. rlhe tarry oil and amndonia. liquor from the condensers is collected in the decanter 23. The ammonia liquor separates and is collected in 24 and the tarry oils are collected in the tank 25. Other tar which may be collected in the system is advantageously blended with the heavy tar in 22 or the tarry oils in 25. For example, tar which separates from the gases in the cross-over main may be withdrawn thru the line 26 into the decanter 23 and then be collected in 25 together with the tarry oils from the condensers.

The collector main 6 may be operated in the same Way. The gases may be sprayed in the goose-necks and collector main thru the sprays 27 and 28. The spraying is preferably so regulated that the gases passing to the cross-over main 11 carry a large percent of oil vapors. The heavy tar and ammonia liquor which collect in the center-box 9 drain into the decanter 29. Ammonia liquor is collected in the tank 30 and the tar is separately collected in 3l.

The gases leave the collector mainv 6 thru the cross-over main 11 and blend with gases which have been enriched by, the distillation of tar in the still 40. The still may be supplied with fresh hot coke oven gases in any suitable manner and the tar may be brought into contact with the gasesby any suitable 'i the collector main or to the hot gas header.

From the hot gas header the gases pass into the still 40.

The still is equipped with suitable means l for spraying tar into the gases. The means -here shown comprise a roll 4G which isl preferably situated at one side of the still 40. It is connected with a motor 47 by which it is rotated at a speed of, for eX- ample, 900-1200 R. P. M. A small amount of tar is retained in the bottom of the still and the roll 46 dips to a slight extent into this tar. By rapid rotation of the roll the tar is sprayed up into the hot gases. The tar is distilledby the gases and the resulting gases and vaporspass thru the tower 48 into the main 49.

The roll throws an intense spray of tar and pitch into the gases and the gases are scrubbed andv practically detarred so that the gases and vapors passing thru the main 49 are substantially free from suspended impurities. Tar spray which may pass from the still with the gases settles out of the gases into the tower 48. The gases in passing thru the tower are sprayed with fresh tar from the nozzle 50. This tar together with the baiiies 51 which may be Raschig rings servesto remove entrained tar which may be suspended in the gases passing thru the tower. The hot gases and vapors serve to preheat and partially distill the tar before it enters the still. The preheated and partially distilled tar is advantageously admitted to the still at a point adjacent to the hot gas header which conveys the hot gases to the still so that the gases and tar pass thru the still in concurrent direction.Y For this purpose the preheated and partially distilled tar which collects in the bottom of the tower 48 is conveyed thru the line 52 and enters the still near the point at which the hot gas header 42 enters the still. l

The tar which is continuously admitted to the still is sprayed into the gases and continuously distilled and pitch is continuously withdrawn from the opposite end of the still thru the trap 53 and the levelling arm 54. The proper depth of tar or pitch Within the still is maintained by adjustment of the levelling arm.

The tar is preferably distilled to pitch of a high melting point, for example, a melting point of 350D or 400o F. This pitch may advantageously be cooled, in an open trough as with a water spray from the line 55, as it leaves the levelling arm and is delivered to the storage bin 56.

According to this invention the total tar from the gases leaving a. plurality ot' ovens or retorts and the heavy tar obtained by partially cooling the gases from other ovens are employed for enriching still other coal distillation gases in the still. The total tar from the gases passing through the collector main 7 viz. the heavier tar from 22 and the tarry oil from 25 are collected in the storage tank 57. The heavy tar from the collector main 6, which is collected in 31 is also supplied to the storage tank 57. This tar is pumped by the pump 58 thru the line 59 to the nozzle 50 which sprays the tar into the tower and from there undistilled residue is conveyedto the pipe 52 tothe still. The tar may be preheated in any suitable manner before being admitted to the tower 48.

There the distillation of the tar is carried to a high melting point pitch, the gases passing off the still carry with them vapors of higher boiling constituents vwhich may be solid or semi-solid at ordinary temperatures. These constituents may advantageously be removed from the gases before they are blended with the gases coming from the collector main G, although the enriched gases may be blended directly with the gases from the main 6. According to the drawings the enriched gases pass thru the condenser before being blended with the gases leaving the collector main 6. This condenser 60 is preferably so operated as to condense only higher boiling constituents and it may be necessary to provide heating Imeans e. g. steam-jackets, etc., to prevent solidilication of such higher boiling constituents in the oil draw-ofi'. The high boiling constituents thus removed are collected in the tank 61.

The resulting gases enriched in constituents of the total tar from the gases which pass thru the collector main 7 and the heavier tar from the gases which pass thru the collector main 6 pass thru the main 62 and blend with gases from the collector main 6 in the gas main 11 or in the condensers 13, 14. The blended gases may be conducted thru the gas main 11 to the condensers as here shown or both mains may separately enter the condensers 13, 14. These condensers 13 and 14 which may be either direct or indirect condensers, are here shown as condensers of the direct type.

wWithin the condensers the gases are sprayed with ammonia liquor. The gases may be fractionally cooled to produce two tarry oil fractions or one total fraction may be obtained.

The condensers drain thru the lines and 66 into the decanters 67 and 68. Both the lines 65 and 66 may drain into the decanter 68 or the line 66 from the condenser 14 may drain into the decanter 68 and the condensate and ammonia liquor withdrawn from the condenser 13 may drain thru the line 65 and be separately collected in the condenser 67. The decanters 67 and 68 are connected with ammonia storage tanks 70 and 71 and tarry oil storage tanks 72 and 73. According to the preferred form of carrying out this invention the total tarry oil produced by the process of my invention may be collected in the decanter 63 and thence in 73.

According to the preferred method of, operation the proportions of the number of ovens connected with the collector main 6 and the collector main 7 and the still 40 respectively is regulated to produce creosoting composition direct in the tarry oil storage tank 73. `The cooling in the collector main 6 is so controlled as to throw down heavier tar and entrained impurities from the gases and yet to leave a desired amount of entrained tarry matter in the gases passing to the cross-over main 11. The distillation within the still 40 is so controlled, according to the preferred method of operation, that higher boiling oils are carried over by the gases thru the main 62 and so that on cooling the boiling range of the product obtained in 73 is suitable for use directly as creosoting composition. Main 11 and valves 7 5 and 76 are provided to allow the diversion of any desired proportion of the gases leaving collector main 6 to condensers 15 and 16 instead of to condensers 13 and 14, or even to divert gases from the collector main 7 to condensers 13 and 14. Thus by regulating the temperature in collector main 6, the amount and type of tar distilled in still 40, the melting point of pitch produced and the relative proportion of gases from the still and from main 6 which enter condensers 13 and 14, excellent control of the character of the tarry oil products made is possible. Substantially the total tar from the gases leaving the ovens connected with the collector main 7 is blended with heavier tar resulting from partial cooling of the gases from other ovens connected with the collector main 6 and these combined tars are distilled in gases from ovens connected to the still 40 to produce the tarry oil product contemplated by this invention.

The following may serve to illustrate how creosoting composition may be made directly at a coke oven plant according to this invention. The example here given involves two collector mains of a coke oven plant of relatively the same length. The ovens and the collector mains, etc. are operated in such a way that in each of the collector mains approximately 3,900 gallons of heavy tar is produced, and that from the gases leaving each main approximately 2,100 gallons of tarry oil would result if the gases leaving each of the collector mains were separately further cooled in a condenser connected with each cross-over main. Such separate cooling, however, is not contemplated bythe invention since enriched gases are blended with the ordinary gases in one of the condensers. In the example any slight variation in the amount of tar which would result from passing the gases from several ovens, for example four or five ovens, into the still has been disregarded.

According to the preferred form of the invention the tar from two collector mains is blended with tarry oil from the condenser connected with one of these mains. On blending 3,900 gallons of heavy tar from each collector main with 2,100 gallons of tarry oil from one condenser, a total of 9,900

gallons of tar is obtained. On distilling this in hot coke oven gases, assuming a yield of oil, 6,930 gallons of distillate oil will be obtained together with 2,970 gallons of hard pitch. The distillate oil passes in the vapor state into one of the condensers. It is there recovered together with the 2,100 gallons ot tarry oil which would be produced in the condenser if enriched gases Were not cooled in this same condenser. By passing both enriched and unenriched gases to this condenser and cooling the gases therein, a total of 9,030 gallons of tarry oil suitable for use as creosoting composition is obtained. In this Way a battery of coke ovens, which ordinarily produce 12,000 gallons total tar comprising heavy tar and tarry oils, may be operated in such a. way as to produce directly a small amount of pitch and more than 7 5% of the total tar yield as creosoting composition.

I claim:

l. The method of producing tarry oils at a coal distillation plant which comprises partially cooling the gases from aI plurality of coal distillation unit-s to separate a heavy tar, subjecting only a portion of the partially cooled gases to further cooling to separate a tarry oil distilling the tar and the tarry oil by direct contact with hot coal distillation gases from one or more other coal distillation units and combining the resulting enriched gases with the remainder of the partially cooled gases and then cooling the combined gases to separate tarry oils.

2. The method of producing tarry oils from hot coal distillation gases which comprises cooling the gases from a plurality of ovens or retorts sutliciently to separate substantially all of the tar therefrom, partially cooling the gases from other ovens or retorts to produce a heavy tar, distilling this heavy tar and the aforementioned tar in the hot coal distillation gases from still other ovens or retorts, blending the resulting enriched gases with the partially cooled gases and subsequently separating a tarry oil from the resulting blended gases by cooling them.

3. The method of producing tarry oil suitable for use as creosoting composition from hot coal distillation gases, which comprises passing the coal distillation gases from a plurality of ovens or retorts to two separate gas-collecto-r mains, partially cooling the gases in each of said mains to separate heavy tar, passing the partially cooled gases from only one collector main to a condenser to separate a tarry oil, blending said tarry oil with the tar from the two collector `mains effecting the distillation of this blended tar by bringing it into intimate contact with gases from other ovens or retorts while these gases are substantially at their maximum temperature, passing the resulting enriched gases to a second condenser,

passing the partially cooled gases from the other collector main to said second condenser, cooling the enriched gases therein together With gases from the second collector main to separate tarry oil therefrom, and separately collecting the resulting tarry oil.

4. The methodof operating two coke oven blocks connected with two separate collector mains and a still for distilling tar, which comprises collecting thega'ses from the coke oven blocks in their respective collector mains and cooling them therein to sepa-rate heavy tar, subjecting the partially cooled gases from only one collector main to further cooling to separate a tarry oil, passing said heavy tar and said tarry oil into said still and bringing them into direct contact with a portion of the hot gases from one of said blocks to effect their distillation, cooling the gases and vapors resulting from the distillation together with the partially cooled gases from the other of said two collector mains to produce a second tarry oil, and separately collecting said second tarry oil.

5. The method of operating a coke oven plant comprising ovens connected with two separate collector mains which comprises partially cooling the gases in the first col.-

lector main, further cooling these gases in condensers connected with this main, diverting the gases from some of the ovens connected with the other collector main to distilling means, passing the gases from the remaining ovens to thisy second collector main, cooling the gases therein so as to separate tar from the gases, distilling the tar from this second collector main together with tar from the first collector main and tarry oil from the condensers connected with this first main in the distilling means by spraying the tar into the gases passing thru the still, thereby distilling the tar and scrubbing the gases, and cooling the resulting gases and vapors and the gases from the second collector main in a second condenser to separate tarry oil therefrom.

6. The method of producing creosoting compositions from hot coal distillation gases which comprises collecting the gases from a plurality of ovens or retorts in two separate gas collector mains and a. still, cooling the gases in the first collector main and subsequently cooling the gases in condensers connected with this main to separate a tar and tarry oil, respectively, from the gases, subjecting the gases in the second collector main to regulated spraying thereby separating tar and entrained matter from the gases, bringing this tar together with the tar and tarry oil from the gases passing thru the lirst collector main into direct contact with the gases passing thru the still and subjecting the combined tar and tarry oil to regulated distillation within the still, to

produce pitch With a melting point of at least 350 F., simultaneously scrubbing the gases Within the still, cooling the resulting gases and vapors to separate higher boiling constituents therefrom, and then blending the gases and vapors thus obtained With the gases of regulated temperature leaving the second collector main and cooling them to separate therefrom a tarry oil suitable for use as creosoting composition Without the addition of distillate thereto.

7. The method of producing creosoting compositions at a coke oven plant, which comprises passing a regulated proportion of the gases produced in the ovens to a still and each of tivo collector mains, cooling the gases in one collector main to separate tar from the gases and further cooling the gases leaving this collector main in a condenser to separate tarry oil therefrom, subjecting the gases in the other collector main to regulated spraying to separate a part, but not all` of the entrained impurities from these gases, bringing the resulting tar together with the tar and the tarry oil from the other gases into regulated direct contact With hotcoke oven gases to distill the combined tar product to pitch with a melting point of at least 250 F., and cooling these gases together with gases from the second collector lnain to separate tarry oil therefrom, which is suitable for use as creosoting composition Without the addition of further distillate thereto.

8. The method of producingcreosoting compositions at a coke oven plant, which comprises passing portions of the gases produced in the ovens in regulated ratios to a still and each of two collector mains, cooling the gases in one collector main to separate tar from the gases and further cooling the gases leaving this collector main in a condenser` to separate tarry oils therefrom, subjecting the gases in the other collector main to regulated spraying, thereby separating a part, but not all, ofthe entrained impurities from these gases, bringing the resulting tar together with other tar and the tarry oil from the other gases into regulated contact With hot coke oven gases to distill the combined tar product to pitch with a melting point of at least 300 F., and partially cooling the resulting gases and vapors to separate high boiling constituents therefrom, and further cooling the enriched gases together With gases from said other collector main, and separately collecting the resulting tarry oil.

In testimony whereof I afliX my signature.

STUART PARMELEE MILLER.

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