US2217703A - Treatment of fluids - Google Patents

Description

Oct 15 1940? A. E. P'Ew. JR.. Er AL 2,217,703

f TREATMENT muros l Filed Feb. 18, 19:56v 2 sheets-sheet 1.

Regenembn Fumes [1 -j T v i AnTHuREPswJR.

BYRAvMoNnQL/asswr ATTORNEY 0&- 15 l940- A. E. PEw. JR., AL 2,217,703

ATTORNEY Patented Oct. 15, 1940 TREATMENT or' FLUIDS Arthur E. Pew, Jr., Bryn Mawr, Pa., and Raymond C. Lassiat, Woodbury, N. J., assignors, by direct and mesne assignments, to Houdry Process Corporation, Wilmington, Del., a corporation of Delaware Application February 18, 19.36, Serial No. 64,488

3 Claims.

The present invention relates to the art of treating fluids and to process and apparatus therefor. It has particular application to processes of the type Where temperature control, especially close or fairly accurate temperature control, is necessary or desirable, as in many contact or catalytic processes and particularly, for example, in the contact or catalytic treatment or conversion of hydrocarbons, whether derived from petroleum, coal, shale or other origin, natural or artificial, although other reactions, such as catalytic oxidations, hydrogenation of organic materials, `etc are of course contemplated. The invention further relates to the use of a, medium in the temperature regulation of the operation, such as steam, various condensible or incondensible gases, or other inert or different fluids, which it is desired to add directly to the fluid to .be treated toimprove or foster .the reaction. Operations with contact masses or catalysts which become contaminated or coated with deposits during'reaction and accordingly are arranged to be alternately on-stream and in regeneration, are among those contemplated.

While the temperature of the treating or contact operations may be controlled in many ways, to make suitable or accurate control available in a practicable sense, it is necessary that the control be effected in an economical aswell as in a suitably accurate manner. Large or excessive expense for` temperature control may, for example, be encountered where a temperature regulating fiuid must be heated to a high temperature, only reduced in temperature a small amount to maintain an endothermic reaction at a slightly lower temperature, and then is merely fed through heat exchangers or to Waste heat boilers or the like. It is further desirable that the system of temperature control have flexibility of operation;

otherwise the investment cost for treating apparatus in a plant, for example, for refining petroleum, c oal or fractions of either, will, in some cases, be so high or excessive as to render non-feasible the operations requiring such a degree 'of temperature regulation.

Itis an object of this invention to devise a system of temperature regulation and suitable apparatus for carrying out the same which will provide for economy in temperature control and flexibility in operation. It is also an object of this invention to supply inert diluent or other fluid, which it is desired to introduce with the reactants, in an economical manner, preferably by using a temperature regulating medium such as process steam which can also be employed as the fluid to be added with the reactants. Another object of this invention is to make the system of temperaturecontrol readily applicable to one, a battery, or any plurality of converters or treating chambers. Other objects include: em- 5 ploying a temperature regulating medium as a vcooling fluid to control an exothermic reaction and then, by Virtue of the heat picked up in the cooling operation, with or without further exchange of heat as may be necessary, using it as a heating fluid to control an endothermic reaction; employing' an inert fluid' for three purposes,

' viz. (l)v as a cooling fluid, (2) as a heating fluid,

and (3) as process steam or equivalent; adding uid to or subtracting it from the stream=oftem l5 perature regulating medium asit passes from one converter or case to another, as desired; effecting the desired temperature control Whether one, two or more or all of the converters or cases are on stream at the same Itime or vice versa, on re- 20 generation at the same time, whether it is desired to have each of the several converters at similar or at differing temperatures, by passing in connectionv with the accompanying drawings in which:

Fig. 1 shows a single converter in vertical section together with apparatus and connections for supplying a temperature regulating fluid, i. e. a heating or cooling fluid, thereto and for employing apart or all of it as process iluid;

Fig. 2 shows a plurality of converters in elevation and one partly in section, together with 4apparatus and connections for passing a temperature regulating fluid therethrough, in series or not, as desired; and

Fig. 3 shows a plurality of converters as in Fig. 2 but-With connections especially arranged and adapted for operation on cycle, i. e. one or more on-stream while the other or others are in regeneration, together with apparatusfor passing hot (or cool) uid'through either while `cool (or hot) fluid'is passed through the other.

In the following discussion, by way of definite illustration, a composite hydrocarbon fluid, specifically afraction or fractions of petroleum, will be considered as being treated. Also water or steam will be taken as the temperature regulating medium, although obviously various other heating or cooling media, particularly fluids which boil at a temperature so that their latent heats of vaporization could be utilized in the temperature regulation, such as propane and/or butane or the like, could be employed; also fluids such as CO2, N2 and H2 can be used as temperature regulating media. Likewise, various fluids' other than petroleum fractions could be acted upon or treated, e. g. other composite hydrocarbon fluids, organic fluids, or inorganic fluids.

Referring in detail to the drawings, in the iigures of which like reference characters denote similar parts, I is a converter surrounded by insulation 2 and having a reaction` chamber in which extend conduits 3, which may be considered as inlet conduits for reactants, and conduits d, which may be considered as outlet or Withdrawal conduits for the products of the reaction. These groups of conduits are provided with perforations or openings 5 and 6, respectively, which are distributed throughout fthe length of each. Surrounding these conduits within the reaction chamber is a suitable contact mass I which may comprise or include various materials which cover the range from those which are inert or substantially inert to those which are highly catalytic to the reaction which is to be performed Within the reaction chamber. The contact mass may consist of any known or desired material, but is preferably in the form of fragments or molded pieces which are, readily susceptible of regeneration in situ. In a number of operations for the refining and conversion of petroleum hydrocarbons, activated hydrosilicate, of alumina and blends of silica and alumina of controlled ratio, either natural or artificial, in the form of small molded pellets or cylinders, either solid or hollow, and with or without the addition of other catalytic materials, such as metals or metallic compounds, have been used with advantage.

Reactants, which may consist of a fraction of petroleum to be treated or converted, may be iny thereby being distributed throughout troduced into the converter I through heater 8 and atomizer 9 by means of pump I0. 'I'he atomizer 9 is optional and may be by-passed or dispensed with where the temperature employed and the nature of the uid do not make atomization necessary or desirable. The heated iluid is introduced into manifolding chamber II of the converter I and from there enters conduits 3 andipasses therefrom through openings 5 therein,

the reaction chamberand brought into contact with the bed of contact mass or catalyst 1. The products of reaction enter conduits 4 through openings 6 therein and, by means of conduits 4, pass from the reaction chamber into manifolding chamber I2 of the converter. From manifolding chamber I2 the reaction products-may pass fromA the converter through the line controlled by valve I3 and thereby be led to storage or to any additional treating apparatus, as desired.

After the reaction has continued for a suitable period of time, depending upon the nature of the particular reaction, thecontact mass l'may become poisoned or contaminated by deposits which are usually burnable and require'regeneration or removal of such contaminants in order l to restore it to a state of desired activity. This purging a regenerating medium such as air or other oxygen-containing gas may be introduced into manifolding chamber II of the converter through line I5, controlled by valve I6 and after following the same paths through the converter that were followed by reactants and reaction products, the products of regeneration or the regeneration fumes may be withdrawn from manifolding chamber I2 of the converter through line I l, controlled by valve I8.

In many (but not all) cases of contact or catalytic conversion or refining of hydrocarbon fractions, the converting or transforming operation is an endothermic reaction which tends to cause the temperature of the reaction chamber and of the contact mass to drop, while the rey generation step is usually ex'othermic in chargeneration and to avoid injury to the contact.

mass or catalyst. The present invention provides apparatus in combination lwith the converter I whereby heat may be added to the reaction chamber during the endothermic reaction and heat may bewithdrawn from the reaction chamber during the exothermic conversion.

During the on-stream or conversion period an inert fluid, such as steam, may be introduced through conduit I9, controlled by valve I9a and forced by pump 20 through heater 21|, wherein any desired additional amount ofheat may be added, and thence through a duct controlled by valve 22 `into the tubular manifolding header 23 located within manifolding chamber I2 but out of fluid communication therewith.

From manifolding header 23 the inert fluid or steam may pass through the U-tubes 24 located within conduits 4 and, after giving up heat to the walls of conduits 4 and to the surrounding contact mass I by radiation and conduction, pass into tubular manifolding headerv 25 and pass from the latter through the line controlled by valve 26. After passing through valve 26,

the steam which is ordinarily still at a temperature as high as or slightly higher than that of the reaction, may be passed through line 2l, controlled by valve 28 to mingle with the reactants and to` be utilized, if desired, in atomizer 9 to assist in the atomization of the reactants' and to increase their temperature slightly. When atomizer 9 is not employed, steam may be introduced into the line between the heater 8 and manifolding chamber II of the converter. In addition to or in lieu of introduction at such point, the steam may be passed through line i 29 controlled by valve 30 and be introduced with `have its temperature adjusted to any desired extent by passing through temperature regulawhole or in part through the line controlled by valve 34.

When the ow of reactants is cut off to give time to effect a regeneration of the contact mass 1, purging of the converter may be effected by passing the steam through line 21 into manifolding chamber II and from manifolding chamber I2 of the converter out through line I1, controlled by valve I8, for example.

When regeneration is begun, as above described, valves 22 andY 26, inter alia, will be closed and valves 35 and 36 will be opened. Cooling fluid such as Water may be introduced through line4 31, controlled by valve 38, and be forced by pump 39 into manifolding header 23. From the latter the Water or equivalent temperature regulating fluid will pass through U- tubes 24, emerge therefrom into manifold 25, and pass from the latter through valve 36 to cooler 40, from which latter the heat regulating fluid will pass as water (or low temperature steam, as desired) and may be recycled by pump 39. Where some steam is desired in admixture with the air or other regeneration fiuid, the same may be Withdrawn from the line 4I, preceding the cooler, and be passed through line 42, controlled by valve 42a into line I5 l' It will be noted that the apparatus shown in Fig. 1 illustrates separate systems for supplying heating and cooling uids, such as 'steam and Water respectively, and also illustrates the use of the temperature controlling medium, i. e. heating or cooling fluid, as fluid which maybe introduced with the reactants or regeneration medium to improve the reaction or regeneration. This type of operation is particularly applicable when Mio it is desired to add additional fluids, such as high temperature steam, to the reactants in'order t'o ,maintain them in vapor phase or otherwise to improve the reaction, although in some.. cases it is advantageous to supply steam or equivalent with the air or other regeneration medium.

In Fig. 2 much of the apparatusshown willv -be readily understood in view of Fig. 1 and the detailed description thereof given above.v Reactants may be introduced into either converter la or Ib by forcing the same through heater 8a by means of pump I0a. In passing to converter la the fluid flows through line 45 controlled by valve 45a., while in passing from' heater 8a to converter Ib fluid passes through line,46 controlled by valve 46a, thence through line 41, controlled by valve 41a, and finally through valve 48a intoconverter Ib. Reaction products pass from converter Ia through line 49, controlled by valve 49a and from converter Ib through line 50 controlled by. valve 50a. Also, reactants may be introduced into converter Ib or converter 'Ia by forcing the same through heater 8b controlled by pump Ib. In passing from heater 8b to converter Ib the fluid passes through line 48 controlled by valve 48a, while in passing from such heater to converter Ia. fluid passes through line 48, thence through line 41, controlled by valve 41a, thence through' line 46, controlled `by valve 46a, and finally through valve 45a into converter la. p

Converters Ia and Ib may both'be operated on-stream at the same time on similar ordifferent reactants, or both may be on regeneration at the same time, or one may be on-stream and stock lfor a cracking reaction, e. g., in the lightl gas oil range. Then this resultant material `may be passed through the other converter to produce gasoline therefrom. One converter can be used for the heavy material and the other or remaining one be used to complete the transformation of the partially converted or lighter material. In short, the converters may be used in series or in parallel on the same or on different charging stocks. 'I'he above discussion as to the way reactant fluids may be introduced and treated is given by way of illustration only because the invention is concerned principally with the matter of temperature control of such reactions or their equivalent.

Let us imagine the situation Where converter I a is undergoing an exothermic regeneration (or reaction) at a temperature Within a range of the order of 900 to l200 F. and converter Ib is being used to carry out an endothermic or on-stream reaction at a temperature of the order of 750 to 950 F. A relatively cool fluid, such as Water at a temperature of 60 to about 300 or 400 F., depending upon pressure, may be introduced through line I controlled by valve 5Ia and forced by pump 52 through line 53, controlled by valve 53a or through heat exchanger or cooler 2Ia through valve 5Ib into tubular manifold 23a and thence through U-tubes 24a extending within conduits 4. The fluid emerges from the U-tubes into tubular manifold 25a, usually in the form of steam at a temperature of the order of 212 to 800 F., depending upon the pressure, andmay be passed through heat exchanger 54 where a further change or increase in temperature is effected, as desired, and then is sent at a temperature of about 50 to 250 F. higher than the reaction temperature, i. e., 800 to 1200 F., through duct 55 into the heat exchange ducts of converter Ib. From the latter the steam, at a reduced temperature of about 25 to 225 F. below that of the steam sent into converter Ib, passes through duct 56duct 51 controlled by valve 51a,

back to duct 5I behind the pump 52 and froml their passage through heater 8a, by introduction through valve 60a; likewise, steam may be introduced into reactants before they enter heater Y 8b by passage through valve 59h or, during their passage through heater 8b, by introduction through valvev 60h. If it is desired to pass steam uns from duct 56 into the reactants subsequent to v' their passage through either heater 8a. or 8b or both, steam may be passed through valve 46h in line 46 and from the latter introduced into the reactants entering either one or both of the converters shown by, an obvious adjustment of valves.

In the case that it is preferred `to use steam of the temperature of that emerging from converter Ia, the same maybe Withdrawn through line 6I, controlled by valve Gla, and then passed therefrom'throughbranch 62 into duct 63. From duct 63 the steam or equivalent may be introduced with the reactants either prior to or during their passage through either heater 0a or heater 8b. If it is desired to pass steam from duct 5I into the reactants subsequent to either or both heaters, steam may be withdrawn from duct 5I through branch 65., controlled by the valve as shown, into line 46. From the latter, steam may be passed through line to converter la or through lines 41 and 48 to converter Ib.

When converter l a isv on-stream with an endothermic reaction, and\converter lb is`undergoing regeneration or an exothermic reaction, heat exchange iliuid admitted through line 5| may be heated in heat exchanger Zla and, following emergence from heat exchange with converter la, the :fluid may be cooled in heat exchanger 54, as desired, before passing through and in heat exchange with the reaction zone of converter Ib. Otherwise, the operation of the temperature control system is very similar to and understandable from the description above given wherewe imagined converter la undergoing an exothermic reaction andthe converter lb an endothermic reaction. Where a very large proportion of the steam or equivalent heat exchange fluid is withdrawn through duct Sito be used as process steam, which may be as high as to '10% or even sometimes 100%, the additional amount of aqueous fluid needed for exchange purposes in converter Ib may be introduced into the circuit through duct 64, controlled by valve 64a. Heat exchange fluid emerging from Ib through line 58 may alsoy be employed in whole or in part as -process steam or may be recirculated through line 51 and valve 51a back to the line leading to converter I a.

Where there are two or more converters, each of which is on a different exothermic reaction than another or others thereof, e. g. one converter is on exothermic reaction at a temperature ofthe order of 500 or 600 F. and another is on an exothermic regeneration at a temperature of the order of 900 to 1200" F., the temperature regulating uid may be passed into heat exchange with the-converter undergoing the low tempera ture reaction in a. range of the-order of atmospheric to 200 F. or so and may be passed therefrom at a temperature of the order of 200 to 400 F., into heat exchange with the converter undergoing regeneration at the higher tempera- 'h The latent heat of vaporization of the ture.

' temperature regulating fluid is usually and preferably employed in the more strongly exothermic reaction, which, in this case, is ordinarily the regeneration. i

One example oi two or more converters operating on different endothermic reactions is the case where one or more converters are employed in a catalytic crackingv or conversion at a temperature of the order of 840 F. and another or others are employed in the catalytic reforming of naphtha at a temperature of the order of 850 to 925 F. Only slight temperature adjustment of the temperature regulating iiuid is required in passing from one converter to another converter which is undergoing a. dierent endothermic reaction.

As above pointed out, `the matter of supplying temperature regulating uid to each converter at the respective temperature desired, without having to do more than to make an adjustment of temperature of the uid in passing from one converter to another, is of great importance from the angle of economics, and is one of the objects of the present invention.

ployed to carry out an endothermic reaction 5 whilel another or others are being used to carry out an exothermic reaction. This apparatus may most readily be understood by resorting to i1- lustration. First let us imagine the situation where converter Ic is in an exothermic regenera- 10 tion and converter Id is being used for an endothermic on-stream reaction. The line indicates the circuit which the heat exchange or temperature regulating iluid may follow. It will be seen that relatively cool uid is forced by pump 15 52c through line 10 into manifolding header 23c or converter I c from which it passes through the U-tubes 24c and then passes into the manifolding header 25e, from which it may pass through line 1| through heater 12,where the temperature of 20 the steam or equivalent may be further increased. 'Ihe steam then may pass through line 13 through the heat exchange apparatus within the converter Id and ,then leaves such apparatus through line 14 from which it may pass through heat ex- 25 changer or cooler 15 and be recirculated through line 16 back to inlet duct 10 behind the pump 52o. Process steam or equivalent vaporizing or process fluid may be withdrawn from line 14 through line 11 to be admixed with reactants near the point 80 where they enter converter Id or may bevwithdrawn through line 18 to be admixed with reactants as they pass through heater 19. Also process steam or the like, as it leaves converter Ic,

may be withdrawn through line and introduced 85 with reactants beforevtheyv enter heater 19, or steam, after it has passed in heat exchange contact with the reaction chamber of converter ld,

may be withdrawn through valve control lines 8| and 82 and introduced with reactants at the same o point preceding the heater 19. l

Next let us take the'I case where converter ld is in regeneration and converter Ic isbn-stream and where the heat regulating medium passes rst in heat exchange with converter I d which is undergoing an exothermic regeneration and then passes through converter- Ic which is onstream, undergoing an endothermic reaction. The` path of flow ofthe temperature regulating medium is illustrated by the further discussion should be required to make clear how this type of operation is carried out, for, taken with the above paragraph andthe flow lines, the operation is self-explanatory. l

Next let us look at Athe situation where con- 55 verter Id is undergoing an exothermic reaction and converter lc is undergoingvan endothermic reaction but where it is desired to pass the temperatureregulating medium iirst in heat exchange with converter vIc and then subsequently, 60

after suitable cooling or heat adjustment, passing it in heat exchange relation with converter ld. 'Ihe path of iiow of the temperature regulating iiuid is indicated by the line and is practically self-explanatory.; It will be seen that iiuids 05 84 and line 85, and then through the cooler or 70 heat exchanger 15 and line 15 back into line 10 between valves 10b and 10c, the former of which is closedin this operation and the latter of which is open. 'Ihe uid then may dow through line I5 to converter Id and beiwithdrawn from the 75 line. No M latter through vaivd duct al and be passed through line 82a back to heater 12, from which it may repeat the cycle. Process steam may bev 14, Reactant uid may -be passed to heater 19 through duct 89v and preheater or heat exchanger or directly through duct 90, as desired.

While the invention is described using two converters to illustrate a plurality, the operation is contemplated in connection with any plurality of converters or reaction chambers. It is obvious that in place of passing steam or equivalent fluid through a single converter on-stream, as illustrated in Fig. 3, we may pass such fiuid through any plurality of converters on-stream; likewise with those on regeneration.

It will be clear that Figs. 2 and 3 show very .flexible types of temperature control apparatus.

The temperature regulating medium may be passed in any succession through the several converters and a portion or all of it may be used as process material, as desired. The matter of iiexibility' of operation of such a system is extremely important where a large investment must be made in a battery of converters and where periodical changes in the manner of using the converters is necessary or desirable. For example, at one time it may be desired to employ one or a plurality of such converters to eiect a viscosity breaking operation on heavy or tarry residual materials and another one or more of such converters to further convert the viscosity broken products emerging from the first converter or converters. Again, it may be desired to use one or more ofsuch converters to effect a catalytic cracking of a gas oil and touse another one or more of such converters to reform naphtha produced in such cracking operation or to rene some or all of the products of such operation. Numerous other desirable variations in operation are encountered in petroleum rening practice. In the absence of exibility of operation of the temperature control system and method of providing for process steam or other iluid capable of fostering the desired treatment or conversion of reactants, the investment cost of apparatus would.

in effect be greatly increased, in that the apparatus would otherwise be only useful for a particular type or narrow scope of operations and duplicationof apparatus would be necessary.

It is to be understood that, while treatment or conversion of reactant iiuids is, in the case of the iiids mentioned by way of illustration. often an endothermic reaction, in some cases the treatmentor conversion of i'luids is an exothermic reaction. Our invention, which concerns temperature control of reactions and supplying of uid for fostering treatment or conversion of reactants, is not 4limited by the illustrations above given but has broad application to the control of reactions coming within the scope of the appended claims, whether a single reaction or a plurality` of similar or different reactions are involved and whether the different reactions are all endothermic, all exothermic, or partly endothermic and partly exothermic. The control of reactions herein described and illustrated is one which has broad application and provides substantial economies in operation and `other advantages, as de- What we claim is: 1. In chemical processes involving'at least two bodies of contact material which are used for ,simultaneously carrying out reactions *having different temperatures of reaction, the method of operation and temperature control of the contact masses which comprises the steps of admitting reactants-to the bodies of contact material in direct `contact therewith to eiect the reactions and withdrawing products of the reactions, conwith the reactants before admitting the reactants to the contact material.

42. Inchemical processes involving a plurality of bodies. of contact material which are used for simultaneously carrying out alternate endoy thermic and exothermic reactions having diierent temperatures of reaction, the method of operation. and temperature control which comprises the steps of admitting reactants to each body of material to effect the reactions and withdrawing the resulting products of reaction, passing an extraneous fluid in indirect heat exchange relation with the bodies of material :in continuous circulation rst through the material undergoing the exothermic reaction at a temperature below the temperature of the reaction in order tol withdraw heat of reaction from the material and raise the temperature of the heat'exchange fluid,

supplying additional heat to furtherv raise the temperature of the uid and passing it in indirect heat exchange relation with the contact material which is undergoing the endothermic reaction at a temperature above that oi this reaction in order to supply heat to the reaction and lower the temperature of the luid, then admixing a portion of the heat exchange fluid with a reaction uid before passage of the reaction fluid to the contact mass undergoing the endothermic reaction, and directing the remainingheat exchange uid at its lowered temperature to the contact material undergoing exothermic reaction.

3. In the treatment or conversion of high boiling composite hydrocarbon fluid to produce lighter hydrocarbons having components in the gasoline boiling range in which a plurality of confined reaction zones, each containing an adsorptive catalytic mass in molded form and comprising a blend of silica and alumina, are employed, the

said catalytic mass in each reaction zone being alternately-on-stream to eiect the desired conversion of reactants and in regeneration to eiect removal of deposits of contaminants lby combustion, one of said reaction zones undergoing regeneration while another is on-stream, said onstream operation being an endothermic reaction carried out at a temperature of the order of 750 F. to 950 F. and at approximately atmospheric pressure and said regeneration being carried out at a higher temperature than the on-stream y operation but not to exceed substantially 1200 F.,

the method of operation and ltemperature control v.

which comprises passing reactant uid into one of said reaction zones and withdrawing products of reaction therefrom, simultaneously passing an oxygen-containing regenerating fluid through v Y another of said-zones .in which the catalytic mass is contaminated with combustible deposits from a y previous on-stream reaction to burn suchdeposits temperature of said fluid substantially above that 10 desired in the zone which is oil-stream, introducit n a heat exchange medium.

in'g a portion of said aqueous fluid which emerges from heat-exchange relation with said zone which is on-stream into admixture with the said reactant-uid passing into the said zone which is ola-stream an'd lowering the temperature of the remaining aqueous duid before again circulating ARTHUR E. PEW, Jn.

RAYMOND C. LABSIAT. 10

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