Патент USA US2411809код для вставки
2,411,809 Patented Nov. 26', 1946 i ' UNITED STATES PATENT‘ orrlca , I .2,41i.so9 ‘ v . APPARATUS FOR SEPARATING FLUID Walter H. Rupp, Mountainside, and Richard ‘0. _ - Wright, Elizabeth, N. J., assignors to Standard’ Oil Development Company, a corporation of Delaware - Original application .July 14,v 1943, Serial No. 494;654. Divided and this application March 23, 1944, Serial No. 527,728 5 Claims. ‘ (Cl. 202-4153) I 4 . 1 _This invention relates to apparatus for sep arating one substance in vapor form from two immiscible liquid substances, and more particu larly it relates to an apparatus for fractionating 2 ‘ ‘ ‘ . ping~ section added onto the lower part of the main scrubbing and fractionating tower. It has now been found that any isobutylene dissolved in the alcohol portion or the fractionat- ' and stripping isobutylene out of the mixed prod 5 ing tower bottoms can be substantially completely rejected from the alcohol phase by diluting the not obtained when regenerating isobutylene from alcohol phase with water to about 2—12% alco an- acid solution thereof. hols. The polymer phase‘ dissolves isobutylene, isobutylene has many important uses‘ ‘as ‘a raw however and is inherently immiscible with water material in the manufacture of important com or the dilute aqueous solution of the alcohols, and mercial products, such as in the manufacture of 10 therefore it is one object of the present invention 2,2,4-trimethyl pentane by polymerizing isobu to separate and remove the alcohol-water solu tylene to (ii-isobutylene and then hydrogenating tion from the bottoms before stripping the latter with steam to recover dissolved isobutylene. _An tylene with a small proportion of a diole?n such 15 other object is to provide means especially adapt ed for ‘effecting this separation and stripping iso as butadiene or isoprene, as well as in the manu butylene from the polymer in the most ‘efficient ' facture of-many other chemical products. How the latter, in the manufacture of synthetic rubber of the butyl rubber type by copolymerizing isobu ever, for these various uses, the isobutylene should. manner. , ' One advantage of this invention is that it per- in most cases be relatively pure for best results“ 2o mlts the stripping of the polymer bottoms sep and a suitable process for obtaining it in desired arately from the much‘larger quantity of alco purity has been to contact mixed ?uids (gase hol-water solution, and thereby effects the strip- ' ous or liquid phase) containing isobutylenewith ping with'a much smaller quantity of steam than a dilute sulfuric acidof, for instance, about 65% would, be necessary to strip the, entire fractionat concentration at ordinary temperature and then 25 ing tower bottoms. Another advantage which re to strip the resulting acid extract to liberate the sults from the one just mentioned is thatvif the isobutylene. In/this mannerlthe stream which stripping is effected in‘ a section added on to the is stripped from the extract consistsof isobutyl bottom of the fractionating tower, this stripping ene, in admixture, with minor amounts, e. g., section may be constructed with a much smaller about 2% to 6% of isobutylene polymers, such 30 size than if the alcohol-water solution were also as di-isobutylene polymers with traces offtri-iso being stripped. A still further advantage is that 'butylene or higher polymers, about 30% or 40% the use of the smaller amount of steam for this of alcohols, chie?ysecondary and tertiary butyl stripping permits a 'relativelyhigher emciency alcohols, and water. One possible method for in the fractionation and scrubbing taking place separating thelisobutylene from these polymer .; 35. in the fractionating tower. and alcohol impurities is wtO fractionate the mix‘ The present invention comprises injection of ture in a tower used as a combination scrubbing the maximum volume of dilution water into, the and fractionating tower in which the vapors rich‘ in isobutylene are fed in at the bottom bf the . top of the scrubbing tower folowed by separat ing the dilute alcohol-polymer mixture into two . tower and water is fed in at the top of the tower 40 separate liquid phases, one the upper lighter for scrubbing the alcohols (which are Water-solu ble) out from the rising vapors, with the result ‘that substantially pure isobutylene gas, having phase consisting essentially of oily polymer con taining isobutylene gas dissolved therein, and the lower phase of dilute alcohol containing substan a purity of abouty90% or 95%,fis removed from tially no isobutylene or polymer. These phases the top of the tower while the bottoms from the 45 may be separated-by gravity "either by settling ' tower consist of a mixture of the scrubbing wa or by centrifuging or by other suitable means, and this separation may be e?ected either in a ter, the alcohols, and the polymers which have accumulated during the fractionation process. settling. drum entirely extraneous from'the frac- ' tionating tower or may be carried out in aset These bottoms also contain a small but substan ~"~“e-tiai ‘amount of isobutylene in solution and here 50 tling section added to the bottom of the fraction-. ating tower. This separation is preferably car tofore, where any .attempt has been made ,to re ried out continuously and in conjunction with a cover this dissolved isobutylene, the entire bot continuously ‘operated scrubbing and fractionat toms stream has been subjected to stripping by a suitable material, such as steam, this being done I ing tower. ' The polymer layer ‘only is sent to a either in a separate tower or in a‘. separate strip oil/stripping section for removal of isobutylene. 2,41 1,809 3. I vThe alcohol-water solution separated in the ' "settling'drum may, if desired, be recycled to the _ extract stripping zone for dehydration to isobu~ 'tylene, or'maybe subjected to further puri?ca > suitable liquid level indicator controls. ~ A balance tion or processing steps to re?ne and concentrate the alcohols for sales uses as such. 4 - phases from the settling drum ‘I and removal of the polymer from the stripping section it! may be\ made automatic as well as continuous by use of ‘ line I: may be provided in order to maintain pres . ‘ sure balance between the overlying vapor space Similarly after the ‘dissolved isobutylene has been stripped from the polymer. the latter may, likewise be subjected to, puri?cation or other’ processing steps, either for use as such or for con in the settling'drum ‘I and the vapor in frac tionating tower 2. The entire equipment may be operated at any desired pressur , such as atmos 10 pheric pressure or super? or sub-atmospheric version ‘into other products of equal or higher , ’ butylene into 2.2,4-trlmethyl pentane by hydroge nation, etc., or for regeneration into isobutylene by heat or catalytic cracking. . pressure. Also, if desired, the settling drum may vbe placed at a lower level, in which case it would, of ‘course, be necessary to‘ pump the polymer solu tion from line 9 into the stripping section 10; 01’ the invention will be better understood from the following description read in combination with the accompanying drawing, in which Fig. I - or in conjunction with,-_the settling drum v‘I, as, _ for instance, using the settling drum 1 for set molecular weight as by converting the di-iso alternative previously suggested in a‘ _'I'he objects, advantages, and further details.15 vAnother general way is the use or a centrifuge in place of, tlingout the major proportion of the alcohol represents a vertical section of a scrubbing and 20 water solution from the oily polymer phase and ‘ fractionating tower with a reduced steam strip- ' then'passing the latter through a centrifuge to ping section beneath it and an extraneous set remove a minor residual, proportion of alcohol- _ tling drum, whereas Fig.‘ II represents the lower water phase. ' , portion of a. fractionating tower and the upper‘, Referring to Fig. II of the drawing, the bottoms portion of a' lower steam stripping section with 25 which'collect in the bottom tray 5 of the frac a ksettling section integrally interposed there . tionating tower 2 are between. In these several ?gures, like reference numerals indicate like‘ parts. Referring to Fig. I, a mixed vapor rich in iso - permitted to ?ow by gravity through line It into the middle portion- of the settling section II constructed. immediately be , and communicating with the fractionating butylene and containing alcohols and small 30 “' neath tower 2. In this settlingsection I5, the alcohol amounts of polymer are fed from an isobutylene water phase settles substantially free of polymer regenerating apparatus‘ not shown, through line and isobutylene, and is removed 'continuously I into scrubbing. and-fractionatin'g tower 2 near through line It while the polymer solution'con the bott om thereof, while water is fed through line 3 into the top of the tower 2 to scrub the 35 taining dissolved isobutylene rises to form ‘a sub stantially clear upper liquid layer ‘and ‘over?ows rising vapors and thereby remove the alcohols down throughthe hollow central portion ll of therefrom which are‘wat'er-soluble, and to dilute the settling section IS on to the toptray of the steam stripping section III constructed imme throughout the tower by suitable heating and/or 40 diately beneath and communicating with the set cooling coils, not shown. It is preferable, when "tling section It. This embodiment of the inven- ' ‘the alcohol so that a polymer layer will separate. The desired ‘ temperatures are maintained tion provides added 'silrnplicity'and e'?iciency in ' scrubbing and fractionating isobutylene‘ to re that it requires a minimum of apparatus and con- . ‘move polymers and alcohols therefrom, to main-' necting- parts and may be made completely auto tain a temperature of about 100° to 150° F; in the bottom of the tower, about 100° to ‘130° F..in the 45 matic with the provision of a liquid level indicator control for regulating the flow of alcohol-water '7 middle portion and about 90° to 110° E. at the top , 'solution'removed' through line’ I6. of the tower. Substantially pure isobutylene If desired, instead of vusing open stripping removed from the top of the tower through line steam, one may use a reboiler, which, of course, 4 and the bottoms which collect in the bottom tray 5 ‘are removed through'1ine\6 into settling 50 would be located in the same position as the strip ping section It). I drum 1 from which the lower alcohol-‘water phase A conventional design of an isobutylene scrub-, . is withdrawn through line 8 and pumped to suit- _ ’ able isobutylene-regenerating apparatus not ‘ ber tower would require a stripping section about shown, while the upper liquid phaserconsisting essentially of. oily polymer-containing isobutylene dissolved ‘therein is removed from the settling _ drum 1 through line .9 and returned to the upper portion of the stripping section I ll constructed below and communicating with the fractionating » ' tower 2. Steam is fed through line ll into the 60 6 times ‘the cross sectional area and about. 10 times the amount of stripping steam as for the _ I system described above. This illustrates numer ically the advantages of the invention in respect to the savings in steam'consumption and in re gard to the reduction in size of the stripping, sec-, tion required. _ _ = Although the invention has been described above as speci?cally applied to the recovery of lower portion of said stripping section III in order to strip the dissolved isobutylene from the de isobutylene from they :fractionating tower bot-' scendlng polymer solution. The isobutylene toms containing polymers, alcohols and water, in stripped from said polymer solution rises out of the stripping section up through the bottom tray 65 its broader aspect, the invention may be applied 5 of the fractionating tower 2 and mixes with the _ to any fractionating» tower where the bottoms other vapors rising therethrough. Polymer liq consist of two or more immisicble' liquids, and ' uid now substantially free from dissolved iso where "the dissolved vapor occurs primarily .in butylene is removed from the stripping section 7 solution in one of these liquids. Other examples l0 through .line I2. .The desired temperature may 70 of applications of this invention are as follows: be maintained in this stripping section III by suit 1. In solvent extraction, for stripping extract able heating and/or cooling coils, not shown. from the liquid solvent. ' ' The equipment just described and illustrated 2. In manufacturing butadiene, for removing in/ Fig. I is advantageously adapted to ‘continuous butenes and butadiene from polymer by-products. operation, and even the removal of the two liquid 75 3. In isopropyl alcohol manufacture, for re 2,411,86Q moving isopropyl alcohol from'polymer by-prod uct. \ .This is a division of Your copending application entitled “Separating ?uids and apparatus there for,” Serial No. 49%,654, ?led July 14, 1943. It is not intended that this invention be lim ited to the specific examples and embodiments which have been given‘ merely for the sake of ii lustration. 1 - ’ ' We claim: I 1. Apparatus for separating one substance in vapor form from two immiscible liquid sub stances, comprising an elongated tower contain means for feeding the supplementary ?uid in ' liquid form into the upper part of the fractionat ing zone. ‘ 3. Apparatus according to claim 1 having means for feeding the supplementary ?uid in vapor form into the lower section of the strip ping zone. ' ‘ ' 4. Apparatus according to claim 1 having means for feeding the supplementary ?uid in liq 10 uid form into the upper part of ‘the fractionating zone, and also'hav'lng means for feeding the'same supplementary ?uid in vapor form into the lower section of the stripping zone. - 5. 'Apparatus according to claim 1 in which the mg a fractionating zone, an intermediate liquid- . 15 said stripping zone has a substantially lesser ca liquid separating zone,'and astripping zone for bottoms from said fractionating zone, means for feeding into said ,fractionating zone near the pacity' than would normally ‘be required for the stripping of the entire bottoms from the frac tionating zone, but su?icient capacity for strip bottom thereof a mixture of ?uids to be sepa ping one liquid separated from the mixed liquid rated, means for removing vapor from the top fractionating bottoms, there being direct vertical 20 of said fractionating zone, means for, conducting vapor connection between the bottom, middle, liquidgbottoms from the fractionating zone into the separation zone, means for removing two separate liquids from the separation zone, means for conducting one of the liquids from said sep aration zone into the stripping zone, means for removing.v vapor and vapor-free liquid bottoms and upper sections of said tower, there being also means .for conducting the mixed liquid bottoms. from the upperor fractionating section of the tower directly into the middle portion of the mid dleior separating section of the tower and means for permitting liquid to over?ow from the upper from said stripping zone, said apparatus also hav portion of the separating zone directly and with ing means for supplying thereto supplementary in the interior of the tower into the upper por ?uid immiscible in the liquid state, with one of tion of the bottom or striprpingv section of the 30 said two immiscible liquid substances, and with condensate of the substance to_be removed in WALTER H. RUPP. vapor form. RICHARD, O. WRIGHT. 2. Apparatus according to claim 1 having tower. ' a \q '