Патент USA US2399882код для вставки
2,399,882 Patentcd May 7, 1946 UNITED STATES PATENT ‘OFFICE 2,399,882 OLEFIN CONCENTRATION Charles E. Morrell, West?eld, James K. Small, Union, and James H. McAteer, Cranford, N. .L, assignors to Standard Oil Development Com pany, a corporation of Delaware No Drawing. Application-November 3, 1944, Serial No. 561,842 13 Claims. (Cl. 260-6815) the acetylenes dissolved therein. Although the This invention relates to improvements in reaction is quite complex, and may involve also processes for concentrating oleilns and relates copolymerization and reaction with‘ components particularly to improvements in processes where of the copper solution, the process is referred to cuprous salt solutions ‘are used as extraction herein for purposes of simplicity as a “polymeri agents in the separation and concentration of zation" and the products as polymerization prod-v ole?ns and dioleilns. ucts. The polymerization products from such a Cuprous salt solutions, especially these con process are quite varied in nature. Some of the» taining ammonia, for example one containing 2 products are liquids which are readily removed to 5 mols cuprous copper, 10.5 to 12 mols am monia and 4 mols of acetic acid and having a 10 from the copper solution by settling or by wash ing with an appropriate solvent such as hydroe pH value of 10.5 to 12.5 have been extensively carbon liquids. Liquid polymers of this type pre developed for concentrating ole?ns and diole dominate when ethyl acetylene is the main acety ilns, for example butadiene from hydrocarbon lenic constituent of the crude butadiene. When mixtures. Cracked petroleum hydrocarbons con-, tain crude butadiene and also small but varying 15 vinyl acetylene is present in large amounts, some plastic or semi-solid materials are also formed. amounts of acetylenic materials having the fol lowing boiling points: . These may be removed by ?ltration. It has been found, however, that in addition to the above types of products some of the products of acetylene polymerization are quite soluble in Vinyl acetylene _________________ _r___...... 41.0 water, therefore also in the aqueous copper solu Ethyl acetylene ______________________ __ 47.7 tion, and are not readily extracted with hydro Dimethyl acetylene __________________ __ 80.4 carbon solvents. They are not removed from the Butadiene__._.._ ______________________ __ 24.06 solution by ordinary filtration. These soluble The total acetylene content of butadiene-con 25 products have not been too well identi?ed since they appear to be a rather complex mixture of taining 04 fractions varies as to the process and compounds some of which contain oxygen, nitro feed stock used in the preparation of the said gen, carbon and hydrogen. At least a portion of hydrocarbon fraction. Steam-cracked stocks these soluble products are highly objectionable in produced at temperatures up to about 1250° F. usually contain less than about 0.1 weight per 30 the butadiene extraction process since they are surface-active materials which tend to promote cent (1000 parts per million) of acetylenes in_the C4 cut. Catalytic dehydrogenation of butenes in foaming of the solution, when contacted with a normal adiabatic operation also produces rela gas, and emulsion formation when the solution is tively low acetylene C4 cuts. Cracking at higher contacted with a liquid hydrocarbon. This tend temperatures up to 1400° F. with steam or air 35 ency to produce foaming and emulsi?cation in increases the acetylenes to about 0.25 to 1.65%, the extraction systems is at least in part believed cracking with air apparently giving the larger due to the fact that these materials greatly lower increase. The use of still higher temperatures of the interfacial tension of the solution with re spect to hydrocarbons. . I about 1400-1800° F‘. in regenerative furnaces pro duces a C4 cut containing from 2 to 5% acet 40 According to this invention it has been found ylenes. that these surface-active materials can be re In the concentration of butadiene it is desir moved from the used aqueous copper solution, able to remove these acetylenes in such a man and the foaming and emulsiflcation tendencies ner that they are not present in the puri?ed buta of the solution thereby decreased, by contacting diene but due to boiling points only methyl and 45 the solution with a variety of, finely divided, in dimethyl acetylene can be separated sufficiently soluble materials, especially those which are by distillation. The dimethyl acetylene contains known to possess high adsorption capacities. no acidic hydrogen and does not form copper These materials include the natural and synthetic acetylides. Vinyl and ethyl acetylene together silicates of metals of groups II and III, the dia with butadiene are readily removed from the hy 50 tomaceous earths, the charcoals, and the like. Especially useful in this connection are magnesi drocarbon mixture by the use of a copper solu tion. One procedure which is in common prac um silicates, aluminum silicates, andv activated carbon. Ion exchange adsorptive substances, tice for preventing these acetylenes from con both organic resins such as the “amberlites” ' taminating the butadiene product is to heat the solution under appropriate conditions (prefer 55 and inorganic agents such as the zeolites, may also be used. Commercial grades of these ma ably after desorption of butadiene) to polymerize - °F. Methyl acetylene ____________________ __ -9.8 2 terials such as Magnesol (a magnesium silicate) and Super Filtrol (an aluminum silicate) are beneficial. Activated Alumina and silica gel are inferior to the above-mentioned preferred sub nitrogen gas through a wet test meter, then through a gas scrubbing bottle containing aque stances. the solution to be tested. The gas then ?ows ’ ous ammonia of proper concentration to provide the same partial pressure of ammonia as that over I The effect of adsorbents on the surface tension of a used solution is illustrated in the following‘ ~ through a rotameter and ?nally into a 500 cc. Exam“: I Portions of a solution of cuprous ammonium acetate which had been used in the concentration graduated cylinder containing v'15 cc. of the cop per solution to be tested. The cylinder diameter is 2 inches. The 7-mm. glass tubing carrying ni~ trogen gas into, the copper solution extends 1 inch below the surface of the solution and has a 1/2-inch of butadiene from'a highly cracked petroleum C4 fraction containing about 2.5% actylenes, and which had developed serious foaming and emul minute; The height to which the solution foams example: fritted glass tip. Nitrogen is passed through the solution at a rate of 750 cc. per minute for one ‘in the cylinder and the length of time ‘required sifying characteristics, were shaken at room tem~ . for the foam to break are observed. perature with 1/2 volume of a powdered adsorbent, centrifuged to remove the adsorbent, and then tested for interfacial tension against a paramnic oil at 25° C. in a du Nuoy interfacial t'ensiometer, with the following results: Solution ' Tests are carried out at room temperature, 32° F. and 110° F. Used solution from a plant operating on a C4 fraction .containing 2.5% acetylenes, foamed to 20 the top of the graduated cylinder in less than a minute, and requires 5 minutes to break. After treating the same solution with Magnesol and removing the Magnesol by ?ltration, the solution foams to only 1/2 the height of the cylinder, and 25 the foam completely breaks in 30 seconds. Other examples of the effectiveness of Magnesol Solid adsorbent Fresh copper solutiom User;Jcopper solution.. and other treating agents are as follows: 0 .............. ._ a] EXAMPLE III . “Amborlite" ‘base exchange) _ "Ambcrlite” anion exchange). Agtivate?lyglumina ......... _. Attepsulgus clay ............. _. _ U u Samples of used copper solution from a pilot 30 plant extracting butadiene from a cracked petro 0!! - _ - _ _ _ _ l - - _ _ _ _ -~ leum C4 fraction containing 0.28% acetylenes were subjected to the following emulsion test: 10 The solution may be contacted with these ma terials in a number of ways. One of these con cc. of the copper solution were mixed with 5 85 cc. of para?inic naphtha (both at 15° F.) and sists of slurrying the solid contact agent in this solution, which may be either hot or cold, prefer ably after the butadiene has been desorbed and either before or after the copper solution insolu ble polymers, have been separated, and subse quently passing the slurry through a ?lter to re move the solid material. Alternatively, the solid shaken vigorously for 30 seconds, then allowed to stand at 15° F. for a maximum time of 5 minutes. The time was observed at which the emulsion was completely broken. When this did not occur in 5 minutes, the per cent of oil layer separated at that time was measured. Solution circulation in the plant was maintained at 50 gallons per hour. The total solution stream was desorbed of butadiene at about 170° F. (:10° F.) then passed through a soaking drum at 180° F. ‘for 40 minutes residence time, then passed through a ?lter (which was by-passed for part treating agent may be used as a precoat on the ?lter and the solution simply passed through this ?lter. In another type of procedure the contact ing agent in pill or lump form may be placed in a tower on supportinggrids and the solution circu lated through this tower. Extremely small of the run) then through coolers, then scrubbed with liquid butenes to remove oily polymers, and marked effects in reducing the emulsi?cation and 50 then recycled to the absorber and stripper tower, through which it was passed countercurrent to the foaming tendencies of the used solutions, as in dicated in the examples below. C4 fraction and to recycled butadiene, respectively. both hydrocarbon streams being maintained in After a certain period of time the solid agent liquid phase in the tower. The results of emul becomes spent and ineffective due to saturation sion tests on solution samples taken at the de of its surface with the adsorbed surface active sorber inlet, and the nature of the ?ltration, are material. Before this condition is reached fresh given in the following table: contact agent should be added to the extraction system. The contact agent may be regenerated Emulsion test in the following manner: It is ?rst washed with aqueous ammonia to remove the copper retained 60 amounts of the solid adsorbent can produce by the agent and then revivified for further use by any of the following methods. - Filter precoet _ Hour (1) subjection to the action of high tempera ture steam. , I Time. 512%,? rated _ (2), Burning of the material to regenerate it 65 900gm. Filter Cel ......................... .. 0-116 . 70 __________ ._ 20 No ?lter ................................... _. 116-262 .......... .. 165 215 20 34 in the same manner as clay used in lubricating oil treatment is regenerated. The following example shows the eifectiveness of one of these contact agents, namely, Magnesol when used in operation. . 70 450 gms Magnosol. v 450 ' ‘Filter OeiIIIIIIIIIIIIIIIIIIIIII EXAIPLI II A test has been devised to measure the tendency of the copper solvent to foam when a gas is passed through it. The test consists in passing 76 . ' _ llilgms. Filter Oel, fresh ?lter each 24 hours... ear-g1) 50 262 """" "ii 271-287 785 .... _. 1. 5 287-368 .......... _ . ' l 357 l. 5 1. 6 2,899,882 3 comprises treating the said mixture or hydrocar EXAMPLE IV In another pilot plant run to extract butadiene _ from a cracked petroleum Ci fraction containing bons containing'diole?ns' and acetylenes with a > cuprous salt solution, separating the cuprous salt solution‘ ‘with the acetylenes and diolefln dis 1.8% acetylenes, in which the absorber and strip?‘ ' solved therein, heating the cuprous salt solution to separate the diole?n and to form polymers, treating the'said cuprous salt solution contain ing the polymers with a solid material having high per were operated with the hydrocarbons in the vapor phase, and the circulation of the solution was the same as described in Example HI, it was observed that ?ltration of the solution through adsorption capacity, separating the solid material a Magnesol precoat substantially reduced the and continuing the use of the cuprous salt solu 10 foaming properties of- the solution, and that when tion in the said separation or diolefins. the filter was by-passed the solution increased 2. The improvement in the separation of ole?ns greatly in foaming properties. The variation in according to claim 1 in which the solid material foaming characteristics with the use of a Magne used is a silicate of a met-a1 of groups II and III. s01 precoated ?lter is indicated in the following 15, 3. The improvement in the separation of ole?ns according to claim 1 in which the solid material table: Foam test at 32° F. 3' , is a magnesium silicate. 4. The improvement in the separation of ole?ns according to claim 1 in ‘which the solid material Cc. foam X breaking-time in sec. Filter prccoat Hour —————-W-——" 380 gins. Magncsol.___ 195 240 262 285 76 6B 60 60 305 329 30 32 380 gms. Filter Cel. changed each 8 hrs._ 5. The improvement in the separation of ole?ns according to claim 1 in which the solid material is of diatomaceous earth. 6. The improvement in the separation oi’ di 25 ole?ns from a mixture of hydrocarbons which Filter by-passcd from hour 329 ___________ .. 358 60 375 140 20 is an activated carbon. comprises contacting the diole?ns with an aque ous solution of 2-5 mols o! cuprous copper, 101/2 ’ to 12 mols of ammonia and 4.mols of acetic acid, 7 EXAMPLE V separating the aqueous solution of cuprous salt The effect of varying the amount of Magnesol 30 from unabsorbed hydrocarbon mixture, heating the separated aqueous cuprous salt solution to re in batch treatments on the foaming properties of cover diole?ns and form polymers of acetylenes, a used cuprous ammonium acetate solution, such treating the aqueous cuprous salt solution with as that described in the above examples when no a ?nely divided insoluble solid adsorptive ma ?lter was used in the plant, is shown in the fol 35 terial, separating the ?nely divided insoluble ad lowing table: sorptive material from the aqueous solution of cuprous salt and recycling the aqueous solution of cuprous salt to absorb more diole?ns. 7.. The improvements in the separation of di 40 olefins according to claim 6 in which the finely di vided insoluble solid adsorptive material is a magnesium silicate. 8. The improvement in the separation of di ole?ns from a mixture of hydrocarbons which Other additives, used in proportions of 3.6 gms./ 45 comprises contacting the diole?ns with an aque ous solution of 2-5 mols of cuprous copper, 101/2 to 12 mols of ammonia and 4 mols of acetic acid, separating the aqueous solution of cuprous salt from unabsorbed hydrocarbon mixture, heating ‘ Cc. loam X break time in sec. Tggsllp" 122311’ WW 60 the separated aqueous cuprous salt solution to re cover diole?ns and form polymers of acetylenes, ?ltering the aqueous cuprous salt solution through 88 600+ 144+ . a ?lter coated with a ?nely divided insoluble solid 300 cc. of the same used copper solution, gave the following results: _ , Additive ‘ Blank __________ ._ Johns Manville "Sorbo A1”____ Dicalite “speed ?ow" ......... __ "-4200" ........ _ . Johns - 89 375 15 88 88 425 385 17 17 Manville “Celite” ______ _ _ _ 325 11 65 adsorptive material. 9. The improvement in the separation of di ole?ns according to claim 8 in which the ?nely divided insoluble solid adsorptive material is a magnesium silicate. The copper solution used in the above examples _ 10. The improvement in the separation of di had the following approximate analysis: 60 ole?ns according to claim 6, in which the finely divided insoluble adsorptive material is an acti Mols per liter vated carbon. Cuprous copper _______________________ _3.0 11. The improvement in the separation of di Cupric copper _______________________ ____ 0.3 ole?ns according to claim 8, in which'the ?nelyv Acetate ______________________________ __ 4.0 Ammonia ____________________________ _.. 11.0 65 divided insoluble solid adsorptive material is an activated carbon. although it will be understood that this invention 12. The improvement in the separation of an is not limited to the treatment of this solution but ole?n from a mixture of hydrocarbons contain is applicable with all cuprous solutions having ing acetylenes using a cuprous salt solution as an the capacity to extract ole?ns or dioleflns from 70 adsorption medium which comprises treating the more saturated hydrocarbons. mixture of hydrocarbons with the cuprous salt We claim: solution, separating the cuprous salt solution with 1. The improvement in the separation of ole?ns acetylenes and an ole?n absorbed therein from from mixtures of hydrocarbons using a cuprous unabsorbed hydrocarbons of the mixture, desorb salt solution as the absorption medium which 75 ing the absorbed ole?n for the separation. of the 4 2,899,882 7 ole?n and polymerizing the absorbed acetylenes ole?n as described in claim 12, in which said sep arated cuprous salt solution, from which the ab sorbed ole?n is desorbed and in which the acetyl enes are polymerized, undergoes the contacting in' the cuprous salt solution separated from the “unabsorbed hydrocarbons or the mixture, contact; , ' ‘ing the thus-separated cuprous salt solution con taining polymerized acetylenes with a solid ma terial-having high adsorption capacity, separat with, then the separating from, the solid material ing the cuprous salt solution i'rom said solid ma terial and continuing the use of the cuprous salt solution as an absorption medium for separation material is supported in lump form. oi’ an ole?n. 13. The improvement in the separation of an on circulating through a zone wherein the solid 10 CHARLES E. MORRELL. JAMES K. SMALL. JAMES H. MCATEER.