Oct. l5, 1946. M. H. ARvEscN REVIVIFYING ADSORPTIVE MATERIAL Filed Dßc. 31, 1940 NN MN 2, ,234 2,409,234 Patented Oct. 15,1946 UNITED ' STATES PATENT oFPlcE 2,409,234 REVIVIFYING ADSORPTIVE MATERIAL Maurice II. Arveson, Flossmoor, Ill., assigner to Standard Oil Company, Chicago, Ill., a corpo» ration of Indiana Application December 31, 1940, Serial No. 372,515 3 claims. (c1. 25a-zeil This invention relates to the decolorization of oils with solid sorbent materials and is directed more particularly to a method and apparatus for the decoloriaation of oils with clays, bauxite, etc., and to the reactivation by burning of the clays, bauxite, etc. The use of solid sorbent materials to improve the color of animal, mineral and vegetable oils is well known. The process is ordinarily carried out in one of two ways. 2 sorptlve power. Again, the loss ofactivity may be due to the presence of local “hot spots” occur ring during the burning, in which excessive tem peratures are developed, destroying the decolorlz ing effect of the clay. Various other factors may enter into this, but it has been found commer cially that decolorizing clays have a rather lim ited life, and can be effectively regenerated only a comparatively small number of times. . An object of my invention is to provide a com In one method the oil l() bination process for the decolorization of oils by and finely divided solid sorbent material are mixed together, and thereafter the oil is recovered from the sorbent by various means such as a' means of solid sorbent materials and the reacti vation of spent sorbent material for reuse as a decolorizing agent; lilter, which retains the solid material contami nated with the coloring matter and permits the improved oil to escape. This is the so-called “contact method.” In the other method, the oil ' It is another object of this invention to provide an improved method and apparatus for the re-l generation by burning of solid sorbent materials used in the decolorization of oils. is allowed to pass down over a body of sorbent material contained in a vessel, the decolorized oil , Still another object of my invention is to pro vide a method and apparatus for the burning of 20 being recovered therefrom, in a “percolation” spent decolorizing material under controlled con manner, The oil is not usually completely de ditions whereby the impairment of the sorbent colorized, i. e. not all of the color bodies are re moved, but suilicient color is removed so that the product is of lighter color than the original. qualities is avoided. . ' r Other objects and advantages of my invention will become apparent as the description thereof 25 A rather finely divided solid is ordinarily em proceeds, read in ,conjunction with the accom ployed for the contact process, having a grain size panying drawing which is a ñow diagram illus of about 200 to 400 mesh; i. e. at least the greater tratìng one embodiment of my invention. part of the solid will pass through a screen having As has been pointed out, my invention is appli 200 meshes per square inch and the majority will cable to the decolorization of animal, vegetable 30 be retained on a screen having 400 meshes per or mineral oils, using solid decolorizing sorbents, square inch, while the percolation method em but for the sake of simplicity it will be described ploys solids of about 30 to 60 mesh. in connection with the contact treatment of a As solid sorbent materials I can use clays, such light viscous oil of petroleum origin. as fuller’s earth, bauxite, silica gels, bentonite, Referring now to the drawing: A petroleum oil montmorillonites, charcoal, particularly activated from line I0 is mixed with a regenerated solid charcoal, or any other porous adsorptive contact sorbent from line II and standpipe I2, passed by , material. 'I'he coloring matter together with line I3 to mixer I4 to obtain the required amount some of the oil adheres to the surface or enters of contact, the contacted oil and solid passing the pores of the sorbent solid, and thereby soon masks its effectiveness. A portion of the coloring 40 matter, etc. can be removed by the use of solvents, or washes, such as naphtha, low boiling alcohols and ketones, as well as other oxygenated or halo- genated organic compounds, However, in order to condition the clay for reuse, it generally must be burned in order to eliminate the remaining organic material. After a limited number of burnings, however, the clay no longer exhibits suñlcient decolorizing action to be elïective for reuse. This may be due to the fact that the coloring matter in the pores of the clay was con verted to carbon during the burning, but the car bon was sufñciently protected so that it was not oxidized to one of the oxides of carbon, and re mained within the pores, iilling it and masking its 55 from mixer I4 to filter I5 via line I6. Although any solid sorbent suitable for decolorizing oils can be employed, I will’ describe my process in con nection with the use of clay. Filter I5 can be any suitable means for separating the decolorized oil from the clay, as for example, a rotating ñlter with a scraper arrangement such that the clay free oil passes out through line I1 while the clal1 is removed from the rotary filter by a scraper or other means (not shown) and conducted from iilter I5 by a screw conveyor or other suitable means.. The clay passes from ñlter I5 through conduit I8 and can suitably be directed through conduit IS to wash vessel 20 which is filled with wash naphtha from line 2|; . The clay settles through 2,409,284 the naphtha in wash tank 28, the naphtha remov ing much of the oil and coloring matter contained on the clay particles and carried therewith by from about 5 to 30 pounds per cubic foot, pref the screw conveyor or other removal means from ñlter I5. The naphtha plus oil can be removed 5 from the upper portion of wash vessel 20 through line 22 and the oil recovered from the naphtha by separate distillation or stripping means (not erably about 10 to about 15 pounds per cubic i'oot. Under these conditions, the solid is in a highly turbulent state, with the result that the temperature in this zone will be uniform. or sub stantially so, from top to bottom and throughout the entire mass. . It desired, burner 48 can be divided into zones shown). The clay is withdrawn from vessel 28 at the -base and can be directed to hopper 23 10 48a, 48b, 48e, etc., separated by gratings, per forated plates or similar dividers, and air and above standpipe 24 by any suitable means such -clay injected at various points. This can be ac as screw conveyor 25. Although other methods oi' complished by directing air from line 42 and clay conveying clay from vessel 28 to hopper 23 can from line 18 through line 88 and line 18a, respec be employed, we have illustrated one method in which hopper 23 is at such a level that conveyor 15 tively, by opening valves 8| and 8l a therein, and manifolding the air and clay through valved lines 25 acts as a “seal" for the naphtha, the naphtha 82, 83 and/or 84 to zones 48a, 46b and 48e. re level in vessel 28 and conveyor 25 being equalized, spectively. Due to the turbulence Within the and therefore avoiding carrying over great quan zones, there will be no localized cooling eil‘ect by tities of naphtha which must subsequently be the injected air, except possibly at the immedi stripped out. 20 ate point of injection where it is quickly dis A fluid is introduced into the bottom of stand sipated, while the injection of air and clay into pipe 24 via line 26 and valve 21 to maintain the clay in a dispersed but nevertheless dense aerated the various zones serves not only to maintain the turbulence or "boiling” within burner 48, but also condition. A particularly suitable aerating fluid is superheated steam which strips the naphtha 25 assures that an ample supply of oxygen is present at all points at all times for the oxidation oi' the from the clay, the steam and naphtha passing carbonaceous deposits on the clay to volatile gases overhead from hopper 23 throughiline 28 and as well as maintaining the temperature in the cooler 28, wherein the steam is totally condensed, various zones at the desired level, thus insuring and directed to separator‘ 38. In separator 30 the substantially complete regeneration of the the condensed steam is withdrawn from the base through line 3| while the recovered naphtha 30 clay. The solids and flue gas plus any excess air pass from clay burner 48 through line 41 and cycled to wash tower 20 by opening valve 33 in waste heat boiler 48. As shown, the vapors and line 34 which joins naphtha feed line 2l. Addi tional steam for stripping naphtha from the clay 35 solids pass through a bank of tubes 48 in a down ward direction but an upilow passage can be uti» can be introduced into the lower part of hopper 23 via line 35. lized. Water enters tubes 48 via line 58 and is converted into steam in this boiler, the steam ex As an alternative method, the clay and oil from iting from waste heat boiler 48 via line 5I and filter I5 and line I8 can be sent directly to hopper passes overhead through line 32 and can be re 23 by a screw conveyor 36, or other suitable 40 can be used in the refinery or plant for any de sired purpose by opening valve 52 in line 53. I1' means, without the intermediate washing step. In this event it is usually advisable to employ steam as the aerating iluid, although ilue gas can be used, the vaporized oil and steam passing overhead from hopper 23 through line 28 and line 32 and discharged through line 31 by open the aerating fluid in standpipe 24 is steam, a portion of the steam, preferably superheated steam, from waste heat boiler 48 can be diverted thereto by opening valve 54 in line 55 which Joins lines 28 and/or 85 leading to standpipe 24 and hopper 23, respectively. ing valve 38 therein to a separate oil recovery system (not shown). A heater 38a can be in The cooled stream of solidand ilue gas passes stalled in line 36 prior to hopper 23 to supply from waste heat boiler 48 through line 58 to cy indirect heat to the naphtha-wet clay. 50 clone separator 51. In cyclone separator 51 suf 'I'he stripped clay from standpipe 24 passes through valve :is 1n line 4o at the base of stand pipe 24 to line 4I through which air or other gas containing free oxygen is passed. Air can be supplied from line 42 and compressor 43 by open ñcient clay is removed from the stream to provide a recycle stream of solids. The separated clay passes to hopper 58 above standpipe 58 via line 88 and is maintained in the standpipe 58 in an aerated condition to prevent bridging. An aerat~ ing valve 44 in line 4I. 'I'he compressed air and ing iiuid, which can suitably 4be compressed ilue clay is then passed via line 45 to clay burner 46 gas, enters standpipe 58 through line 8l con trolled by valve 62 therein. Additional aeratmg` maintained at a suitable burning temperature such as, for instance, from about 950 to 11û0° F. iluid can be injected into hopper 58 via line In clay burner 46 the air and generated ilue gas 60 63 and valve 84, the iluids from both sources pass with the clay pass upward at low velocity, the ing from hopper 58 via line 65 which joins line velocity preferably being suñlciently low so that 66 from cyclone separator 51. Clay from stand there will be considerable hold-up of clay in the pipe 58 passes through line 81 and valve 88 which burning zone. For example, linear velocities o1' can be any suitable metering valve, slide valve, the order of 1 to 2 feet per second are suitable 65 star valve, etc., and is picked up by a stream of for contact clays of 200 to 400 mesh and higher air in line 10 and recycled to clay burner 48 velocities for coarser clays. Under these condi through line 45 together with the clay-and-air tions there is a decided increase in the concen stream from standpipe 24 and injected into the tration of clay per unit volume in the clay burner various zones in clay burner 48 by line 88 as pre as compared with the entering concentration of 70 viously described. The combined streams are clay, this being due to a "settling" of the clay discharged to clay burner 46 at a rate sumcient with respect to the upwardly ilowing stream of to maintain the desired temperature level in the gas. A preferred operating condition is to main burning zones. The air for recycling the clay tain such a quantity of clay in the burner 46 from standpipe 5-8 can be obtained from the same that the density of the clay plus vapors will be source_as that used for directing the clay from 2,409,234 standpipe 2l by opening valve 89 in line 10 which 6 ing, wherein the temperature of one part of the catalyst mass escapes control and the temperature rises to such heights that the decolorizing activity The balance of the clay and the ilue gas from of the clay is substantially destroyed, is eliminated cyclone separator 51 passes via line 86 and further cooling equipment 1I to a series of solid-vapor 5 in my process. DueI to the turbulent effect at tained in the low velocity upiìow burner, the separators 12 and 13, a portion of the solid mate temperature from top to bottom is substantially rials being separated in cyclone separator 12 while uniform, with no opportunity for localized over the remainder plus the ñue gas passes overhead heating. Also, the recirculation of cooled clay has through line 14 to cyclone separator 13 wherein substantially all of the remaining solids are re 10 a temperature controlling effect. Since there is no organic material present to burn in the covered, solids from both cyclone separator 12 presence of oxygen, the recirculated» clay does and cyclone separator 13 passing via lines 15, and not become heated by combustion, and absorbs 16, respectively, to hopper 11 and standpipe l2. heat from the surrounding particles from which Flue gas is vented from cyclone separator 13 via line 19 and line 8U by opening valve 8| therein, 15 organic matter is being burned. The recirculated clay is dispersed throughout the clay burner and or can be recycled by opening valve 82 in line removes heat substantially equally from all parts > 83 having compressor 84 therein to line 82 and/or within the burner zones. For these reasons none 63 in standpipe 59 and hopper 58, respectively, of the decolorizing emciency of the clay is de and/or to line 85 and/or line 88 to standpipe 18 stroyed or impaired. and hopper 11 by opening valve 81 in line 88 lead leads from line I2. . Another advantage of my process is that it can ing from line 83. The clay is accumulated in be carried out in'a “closed system,” i. e. the clay hopper 11 and standpipe l2 and stored pending or other solid sorbent material need not be ex its introduction into oil line I0 as previously de posed to the atmosphere at any time. In the scribed. Fluid from outside sources can also be introduced through line 85 to standpipe I2 or 25 ordinary commercial regeneration of spent clay from the decolorization of oils, the clay is allowed through line 86 to hopper 11 in order to maintain to remain in storage bins until used for decoloriza ` the clay in an aerated condition without bridging. It is perfectly possible t0 employ my process tion of further quantities of oil. This permits i5 will be replaced by a percolation vessel illled with c1ay of from about 3o to sd mesh, the clay bodies from oils, it does make the clay somewhat less eiiicient, since al1 moisture must be replaced by oil in the clay, so that the clay becomes prefer the clay to pick up various amounts of moisture for the reactivation of clay or other solid sorbent material in a percolation process rather than a 30 from the atmosphere, and while this does not destroy the" ability of theA clay to remove color contact process as illustrated. In this event ?llter being directed from‘standpipe l2 to the percola tion unit. As soon as the decolorizing activity 35 entially oil-wettable, rather than Water-wettable. In case a considerable amount of moisture was of the clay is exhausted, as evidenced by the present in the clay, the oil therefrom may at ñrst failure of the clay to remove suilicient coloring have a “haze” or cloud, due to the presence of bodies from the oil, the stream of oil may be dis minute amounts of Water. In my process, the continued and the clay removed from the percola tor and processed according to either of the 40 clay is recycled within a moisture-free system, and returned to the decolorization step, whether previously described methods, i. e. either by contact or percolation,` without exposure to the naphtha washing with steam stripping of the atmosphere. Moreover, by maintaining the clay naphtha from the clay, or by steam stripping of in the storage bin and accompanying standpipe in the oil and color bodies prior to burning. Alternately, after the oil stream has been di 45 an aerated condition, bridging of the solid sorbent is avoided, and crushing or packing of the clay verted from the percolation unit, the oil remain reduced to a minimum. ing and a part of the coloring matter can be Another advantage of my process is that it is washed from the clay by flooding the unit with continuous. The ordinary decolorization process naphtha or other suitable solvent, the oil-solvent wash withdrawn, and the clay steamed to remove 50 is carried out batchwise, particularly as regards the clay regeneration, there being so far as I the remaining solvent prior to withdrawing the know, no provisions in which a solid sorbent ma clay from the percolation unit for burning. It is terial is continuously removed from a. decoloriza usually desirable, particularly with percolation tion zone, reburned and returned to the decolori processes, to employ a series of percolation vessels so that while one is being regenerated the percola 55 zation without intermittent storage, either before tion can continue in an alternate vessel. ' or after reviviiicatlon. Although I have illustrated one embodiment of my invention, it should be understood that this ñcient use of solid sorbent material in the de is by way of illustration and not by way of limi colorization of oils, including a higher yield of oil of a desired color per ton of clay. During re 60 tation, and that I do not intend to be strictly bound thereby. Also, for. the sake of simplicity generation in a low velocity upñow burner of the various details have been omitted, such as pumps, type described there is more opportunity for the By my process I am able to obtain a more ef iutomatic control means, heat exchanges, etc., all of which will be readily supplied by one skilled in the previously employed clay-burning furnaces, 65 the art wishing to practice my invention. individual clay particles to be freed of their mask ing deposits than is possible in such apparatus as where the solid material is heated substantially as a mass. The upiiow turbulence of my process per I claim: , 1. 'I'he process for the reviviñcation of solid contacting material contaminated with adsorbed mits each particle to be contacted with oxygen hydrocarbon matter from the decolorization of bearing gas at elevated temperatures, so that all parts of the particle can be reached while in the 70 oils which comprises dispersing said solid con tacting material in a stream of air, introducing ordinary apparatus the particles, resting one upon said stream of air and solid contacting material the other, may act as a shield to prevent the com into an up-flow burning zone, continuously set plete burning out of all the coloring matter and tling out a portion of the solid contacting mate hydrocarbon materials contained thereon. More over, the development of “hot spots” during burn 75 rial from the stream continuously passing through 7 2.4mm the burning zone whereby the solid contacting material within the burning mno is maintained in a turbulent mass having a density of between about 5 and about 30 pounds per cubic foot. main 8 a substantially constant regeneration tempera ture level. separating regenerated contact mate rial from regeneration gases, eiiecting transfer ot the separated contact material by the pressure taining uniform temperature throughout said -5 head developed by an aerated column of said ma burning zone suilicient to' remove substantially terial and introducing a gas into said column for all of the adsorbed hydrocarbon matter iromsaid solid contacting material, introducing at'verueal. maintaining the solids therein in aerated condi ` tion. ly spaced points additional quantities of gases 3. The method oi.' revivii’yingsolid contact ina into the turbulent mass maintained within the 'l0 terial of small particle size which has become de burning zone continuously withdrawing reviviiled solid contacting material overhead from said burning zone, cooling the withdrawn stream oi’ gases and reviviiied contacting material, recover . activated by liquid phase contact with an oil in a decolorizing process which method comprises in troducing such deactivated contact material at the .top of a column, introducing a gas into said ing the revivifled contacting material from the m column tor maintaining the solids therein in said gases, and accumulating the recovered solid aerated condition and for eiIecting a stripping of contacting material in an aerated dense phase. said solids, dispersing solids from the base ot said 2. The method of revivifying solid contact ma column into a stream of an oxidizing gas, the terial having an average particle size smaller than pressure head at the base oi.' said column being 200 mesh which material has been deactivated by 20 sumcient to effect the dispersing of said solids in liquid phase contact with an oil in a decoloriza said stream. transferring dispersed solids by said tion process which method comprises conveying stream to a vertical regeneration zone oi' large such contact material to the top of a standpipe, horizontal cross-sectional area and introducing introducing an aerating and stripping gas at a said stream into said zone at a low level therein, low point in said standpipe, passing said contact 25 passing gases upwardly in the regeneration zone material downwardly through said standpipe at such vertical velocity as to maintain the con countercurrent to upfiowing aeration and strip tact material as a suspended dense turbulent ping gas, dispersing stripped contact material mass therein characterized by substantially uni from the base of the standpipe into a stream of form temperature from ' top to bottom and an oxidizing gas, introducing said oxidizing gas 30 throughout the entire mass of contact material. stream at a low point in a vertical regeneration abstracting heat from said regeneration zone at zone of large horizontal cross-sectional area, pass such a rate as to maintain a uniform temperature ing gases upwardly in the regeneration zone at at a substantially constant regeneration temper a velocity in the range of about 1 foot to about 2 ature level, separating regenerated contact mate feet per second whereby a large amount of said 35 rial from regeneration gases, removing the sep contact material is maintained in said zone as a arated material as a downwardly moving aerated suspended dense turbulent mass characterized by solids column, introducing a gas into said column a substantially uniform temperature from top to for maintaining the solids therein in aerated con bottom and throughout the entire mass, abstract dition and dispersing solids from the base of said ing heat from said regeneration zone at such a 40 column in a second iluid stream. rate as to maintain the uniform temperature at ' MAURICE H. ARVESON.