Патент USA US2411808код для вставки
Nov. 26, 1946. 'W_H,RUPP " ET AL ' 2,411,808 \ SEPARATION OF ‘HYDROCARBONS FROM WATER MISCIBLE LIQUIDS BY DISTILLATION AND WASHING ‘ Filed July 14, 1943 2,411,808 ’ Patented Nov. 26, 1946 UNITED STATES PATENT orrlcs -_ 2,411,808 ' ROCARBONS FROM OF HYD SEPARATION WATER MISCIBLE LIQUIDS BY DISTILLA TION AND WASHING Richard 0. Walter H. Rupp, Mountainside, and Standard to Wright, Elizabeth, N. J., assignors' a corporation of Oil Development Company, Delaware Application July 14, 1943, Serial No. 494,654 8 Claims. 1 (Cl. 202-395) added on to the-lower part of the main scrubbing and fractionating tower. process of separating ' This invention relates to a one substance in vapor form from two immiscible It has now been found that any isobutylene dis solved in the alcohol portion of the fractionating tower bottoms can be substantially completely rejected from the alcohol phase'by diluting the alcohol phase with water to about 242% alcohols. The polymer phase dissolves isobutylene, however liquid substances, and more particularly it re and apparatus for iractionating and stripping isobutylene out of-the mixed prod ' not obtained when regenerating isobutylene from an acid solution thereof. and is inherently immiscible with water or the Isobutylene has many important uses as a raw material in the manufacture of important com mercial products, such as in the manufacture of . dilute aqueous solution of the alcohols, and there fore it is one object of the present invention to separate and remove the alcohol-water solution from the bottoms before stripping the latter with butylene to di-isobutylene and then hydrogenat steam to recover dissolved isobutylene. Another ing the latter, in the manufacture of synthetic rubber of the butyl rubber type by copolymerizing '15 object is to provide means especially adapted for effecting this separation and stripping isobutyl isobutylene with a small proportion of a diole?n ene from the polymer in the most efficient man such as butadiene or isoprene, as well as in the‘ products. ’manufacture of many other chemical ner. One advantage of this invention is that it per However, for these various uses, the isobutylene should in most cases be relatively pure for best 20 mits the stripping oi the polymer bottoms separa rately from the much larger quantity of alcohol results, and a suitable process for obtaining it in water solution, and thereby e?ects the stripping desired purity has been to contact mixed fluids with a much smaller quantity of eam than would (gaseous or liquid phase) containing isobutylene be necessary to strip the entire fractionating with a dilute sulfuric, acid of, for instance, about ordinary’ temperature and tower bottoms. Another advantage which re 25 sults from the one just mentioned is that if the . 65% concentration‘ at then to strip the resulting acid extract to 'lib stripping is effected in a section added on to the erate the isobutylene. In this manner the stream bottom of the fractionating tower, this stripping which is stripped from the extract consists of iso section may be constructed with a much smaller butylene, in admixture with minor amounts, e. g., about 2% to 6% or isobutylene polymers, such as 30 size. than if the alcohol-water solution were also being stripped. A still further advantage is that (ll-isobutylene polymers with traces of tri-iso the use or the smaller amount of steam for this butylene or higher polymers, about 30% or 40% stripping permits a-relatively higher e?iciency in of alcohols, chie?y secondary and tertiary butyl alcohols, and water. One possible method for separating the isobutylene from these polymer and alcohol impurities is to fractionate the mixd the fractionation and scrubbing taking place in fractionating tower. . 35 the.The present invention comprises injection of ture in a tower used as a combination scrubbing and iractionating tower in which the vapors rich in isobutylene are fed in at the bottom of the the maximum volume of dilution water into the top of the‘scrubbing tower followed byseparating . the dilute alcohol-polymer mixture into two sep tower and water is fed in at thetop of the tower 40 arate liquid phases, one the upper lighter phase consisting essentially of oily polymer containing for scrubbing the alcohols (which are water-solu isobutylene gas dissolved therein, and the lower ble) out from the rising vapors, with the result phase of dilute alcohol containing substantially that substantially pure isobutylene gas, having a no isobutylene or polymer. These phases may be purity of about 90% or 95%, is removed from the separated by gravity either by settling or by cenv top of the tower while the bottoms from the tower 45 trifuglng or by other suitable means, and this consists of a mixture of the‘ scrubbing water, the separation may be effected either in a settling alcohols, and the polymers which have accumu drum entirely extraneous from the fractionating lated during the fractionation process. These be carried out in a settling section bottoms also contain a ' small but substantial added to the bottom of the iractionating tower. 50 amount of isobutylene in solution, and heretofore, where any attempt has been made to recover this dissolved isobutylene, the entire bottoms stream ' has been subjected to stripping by a suitable ma terial, such a steam, this being done either in a separate tower or in a separate stripping‘ section This separation is preferably carried out continu ously and in conjunction with a continuously operated scrubbing and fractionating tower. The polymer layer only is sent to a. stripping section for removal of isobutylene. - _ 2,411,808 4 The alcohol-water solution separated in the settling drum may, if desired, be recycled to the operation, and even th phases from the settli e removal 01' the two liquid extract stripping zone for dehydration to iso trate the alcohols for sales uses as such. ng drum 1 and removal of th butylene, or may be subjected to further puri_ ?cation or processing steps to re?ne and concen ' Similarly after the dissolved isobutylene has 10 mospheric pressure or super, > molecular weight as by converting the dl-isobu or sub-atmospheric pressure. Also, if desired, the settling drum may be placed at a lower level, in w hich-case it would, tylene into 2,2,4-trimethyl pentane by hydrogena tion, etc., or for regeneration into isobutylene by heat or catalytic cracking. The objects, advantages, and further details of the invention will be better understood from the following description read in combination with the accompanying drawing, in which Fig. I represents a vertical section of a scrubbing and fractionatlng tower with a reduced steam strip ' ' 20 xtraneous set remove a minor residual tling section integrally interpos In these several ?gures, like ed therebetween. reference numerals indicate like parts. water phase. Referring to Fig. II of the drawing, 25 the bot toms which coll ect in the bottom tray 5 of the fractionating to wer flow by 30 beneath and communicating with the fractionat 35 mer' and isobutylene, and is removed continu ously through line I6 while the polymer solution ing vapors and thereby remove the alcohols therefrom which are water-soluble, and to dilute the alcohol so that a polymer layer will sep arate. The desired temperatures are maintained‘ 40 isobutylene to re move polymers and alcohols therefrom,'to main ; tain a temperature of about 100° to 150° F. in the bottom of the tower, about 100° to 130° F, in the 45 automatic with the provision of a liquid level in dicator control for regulating the flow of alcohol middle portion and about 90° to 110° F. at the top water solution removed through line “if of the tower. Substantially pure isobutylene is If desired, instead, of using . open stripping steam, one may use a reboiler, which, of course, 50 would be located in the same position as the strip ping section II). A conventional design of an isobutylene scrub ber tower would require a stripping section about 6 times the cross sectional area and about 10 shown, while the upper liquid phase consisting essentially of oily polymer-containing isobutylene 55 times the amount of stripping steam as for the system described above. This illustrates numeri ‘dissolved therein is removed from the settling cally the advantages of the invention in respect drum 1 through line 9 and returned to the upper to the savings in steam consumption and in re portion of the stripping section Ill constructed gard to the reduction in size of the stripping‘ sec below and communicating with the fractionating 60 tion required. tower 2. Steam is fed through line I I into the Although the in vention has been described lower portion of said strippingsection ID in order above as specifically applied to the recovery of to strip the dissolved isobutylene from the de isobutylene from t he fractionating tower bot scending polymer solution. The isobutylene able isobutylene-regenerating apparatus not toms containing polymers, alcohols and water, ution rises out of ' the stripping section up through the bottom tray 65 in its. broader as pect, the invention may be ap~ plied to any fractionating tower where the vbot 5 of the fractionating tower 2 and mixes with the other vapors rising therethrough. Polymer liquid toms consist of two or more immiscible liquids, and where the dissolved vapor occurs primarily now substantially free from dissolved isobutylene in solution in one of these liquids. Other ex is removed from the stripping section III through ‘ stripped from said polymer 501 line II. The desired temperature may be main tained in this stripping section III by suitable heating and/or cooling coils, not shown. ' The equipment just described and illustrated in Fig. I is advantageously adapted to continuous 70 amples of applications of this invention are as follows: ‘ v 1. In a solvent extraction, for stripping ex tract from the liquid solvent.v 2. In manufacturing butadiene, for removing 75 butenes and butadiene from pol ymer lay-products. liquid and a higher b0 ng hydrocarbon liquid . i1‘ , , . 3. In isopropyl alcohol manufacture, for re moving isopropyl alcohol from polymer by immiscible in water in a fractionation zone, said product. intended that this invention be limited It is not to the speci?c examples and embodiments which and the hydrocarbon liquid being obtained in ad mixture with the water-miscible organic liquid have been given merely for tion'. normally gaseous hydrocarbon being removed I ion of said fractionation zone at a lower portion of said fractionating zone, the . improvement which comprises adjusting the di the. sake of illustra lution of said water-miscible organic liquid with . admixture to reject dissolved nor We claim: separating isobutylene in 10 1. In a process of mally gaseous hydrocarbon substances there of alcohols, water and from, separating the hydrocarbon liquid from the diluted water-miscible organic liquid freed of the normally gaseous hydrocarbon that has been rejected therefrom, then stripping the separated hydrocarbon liquid to remove dissolved ‘normally polymer containing dissolved‘ isobutylene by frac ' the isobutylene vapor is removed overhead and the other mate rials in liquid form are mixed bot toms, the improvement comprising separating 15 gaseous hydrocarbon therefrom, and recovering said mixed bottoms into two immiscible liquids, a heavier one consisting essentially of water ‘con dissolved therein, su?icient water ‘ dilute the mixture to about 2-12% alcohol strength, whereby isobutylene is dthe hydrocarbon from a 20 uid mixed with 'a higher rejected from the alcohol-water layer an lighter one consisting essentially of polymer-con taining isobutylene dissolved stripping therein, removing the poly-. V the alcohol-water phasethe anddissolved isobutylene mer phase to remove uid in a fractionation zone from which the more , hydrocarbon is removed overhead ' mally gaseous base, the improvement which coma introducing scrubbing water into an upper part of the fractionation zone, diluting the ‘waters 27s miscible organic liquid with said scrubbing water after the scrubbing water has descended to a lower part of the fractionation zone to reiect m therefrom. 2. Process according to claim 1; bottoms are ' miscible liquids 30 tionation place, and containingtakes dissolved isobutylene vapor is stripped in the lower part of the fractionating zone to major ' propor 3. In a process of, separating a ininor propor tion of isobutylene vapor from a tion of alcohols and polymers, by subjecting a‘ mixture of said compounds to fractionation and recover isobutylene. ' water scrubbing, and removing ’ countercurrent isobutylene as vapor, and alcohols, polymers and as a mixture, the improvement solved normally gaseous hydrocarbon from ad water-miscible organic liquid mixed with. the higher boiling hydrocarbonliquld, separating said hydrocarbon liquid from the diluted water immiscible organic liquid, pass _ "hydrocarbon liquid into a stripping zone wherein dissolved normally gaseous hydr stripped therefrom, and passing ~normally gaseous hydrocarbon in gaseous phase from said stripping zone up through the fractionation zone counter currentiy to the scrubbing water for removal overhead from the fractionation zone. Process according to claim in which the 6. admixture is separated by hydrocarbon liquid the diluted water-miscible organic gravity from zone is in a bottomlporliquid and the stripping ' tion zone, passing the'.bottoms tionation zone by gravity into a settling zone 45 of the fractionating zone. wherein gravity separation takes'placc, removing ' .tion ‘1. Process accord 5 in which the is separated by gravity from ' an alcohol-water layer from the bottom of said hydrocarbon liquid _ settling zone, and passing a polymer layer con the diluted water-miscible organic liquid in-a zone _ vapor dissolved therein from thessfractionation zone. theupper portion of said settling zone into a 50 outside 8. accor g to claim 5 in which the stripp dissolved isobutylene is hydrocarbon liquid is separated by gravity from removed from the polymer layer, removing iso the diulted water-miscible organic liquid in a zone , butylene-free polymer bottom ofsaid stripping zone, and recovering the isobutylene > ‘ .4. In the process of‘ separating a normally gase 55 irom a water-miscible‘ organic rreedby stripping. ous hydrocarbon superimposed upon the stripping zone. - ‘ ‘ WALTER H. RUPP. RIOHARD O. WRIGHT.