US1820573A - Process of and apparatus for distilling oil - Google Patents

Description

Aug. 25, 1931. H. N. LYONS 1,820,573

PROCESS OF AND APPARATUS FOR DISTILLING OIL I I Filed April 17, 192 2 Sheets-Sheet 1 BArrE/rY arcoA/r/Nl/aus STILLS a l- $51 attowwmg I Aug. 25, 1931. H.'N. LYONS 7 1,820,573

PROCESS OF AND APPARATUS FOR DIS [FILLING OIL I I Filed April 17, 1923 2 Sheets-Sheet 2 68 awvmrlfoz Patented Aug. 25, 1931 UNITED STA HENRY n. LYONS, or DOVER, new JERSEY,

new YORK, n.1,

COMPANY, OF

IBOGESS AssIeNoa, 'ro nonsa'ry nsssmon A CORPORATION or DELAWARE OF AND APPARATUS FOR DISTILLING'OIL Application filed. April 17, 1923. Serial No. 682,598.

This invention relates to a process of and apparatus for distilling oil, and more particularly to a process and apparatus whereby oil is distilled in such a manner as to di- ,5 rectly separate the various oil fractions therefrom without the necessity of repeated dis'tillations. I

In the ordinary distillation of oil, the crude or other oil to be distilled, is vaporized in a single still, various cuts bein made at different temperatures to remove t e various fractions thereof. The various fractions such as gasoline, kerosene, lubricating oils,

etcI, which are separately obtained are then- 1 redistilled to withdraw the lighter and heavier portions associated therewith from the desired fractions. The lighter portion distilled from each fraction is added to the next lighter fraction and the heavier portion therefrom is added to the next heavier fraction. For example, in distilling the kerosene fraction the more volatile ortion is added to the asoline fraction an due heavier tian kerosene is added to the gas oil or next heavier fraction. In the same manner in the distillation of the gasoline, cut the heavier portion, which constitutes the higher boiling material, is separated from the gasoline and is added to the kerosene fraction; The-various fractions after their distillation to .remove undesired hydrocarbons therefrom are chemically treated to remove undesired impurities. carrying out the various distillations a large amount of fuel is employed and a great deal of time is consumed for the various operations. Moreover, with the method generally employed for the separation of the various fractions from oil, a large layout of apparatus is necessary per unit of product obtained. I

The primary object of the present invention is to provide aprocess and apparatus whereby oil "may be distilled to obtain the desiredfinal fractions in one distillation.

Another object of the invention is to provide a process ,and apparatus whereby the fuel consumption 'in'the distillation of oil issubstantially reduced.

A further object of the invention is'to the resie/ provide a Inb fractionate vapors of different oil fractions in a fractionating tower so that the vapors of the heavier oil fractions do not come into contact {with the vapors of lighter fractions during their condensation, thereby avoiding solution of the lighter vapors i heavier condensed oil bodies which would require heat for their subsequent removal thererom. ,A further' object of the invention is to carry on the condensation of the various oil vapor fractions produced from the oil being distilled in such a manner-that the lowest boilin 0r lightest portions of the vapors'of each raction Will be passed into and mixed with the vapors of the next lower boiling fraction undergoing condensation, while the highest boiling constituents condensed from. each vapor fraction will be mixed with the vapors and condensate of the next higher boiling fraction. 'A- further Object of the invention is to bubbling tower which is suitable for separating oil vapors to obtain liquid fractions of varying densities at different, vertical levels, having substantially uniform I density at a given level therein.

. A further object of the invention is to provide a bubbling tower in which vapors of varying densities may be supplied to the tower at different levels corresponding substantially to the character of the liquids to e withdrawn at that level.

With these and other Objects in view the invention consists in the process and ap paratus for distilling oil hereinafter described and particularly defined in the claims.

The present invention is based upon the discovery that the various oil fractions which it is desired to obtain may be separated from oil and the higher and lower boiling hydrocarbons may be removed from each fraction all in one operation. Instead of having a single still and distilling off the various fractions therein the oil is passed through a series of stills continuously 1n such a manner that a series of vapor fractions are simultaneously obtained cor-/ responding to the usual vapor cuts of gaso- Ill line, kerosene, and heavier oils. All of the vapors from the series of stills are passed directly into a single fractionating column wherein the vapor fractions. remain, separate except for the separation of the lighter and heavier constituents from each fraction' which, with the exception of the gasoline portion, are added to the next lighter and next heavier fraction respectively. The various oil fractions with the exception of the gasoline fraction are condensed in the column. The various fractions from the oil are therefore obtained directly without the necessity of repeated distillations and are then ready for the usual chemical process of purification.

.The invention may be best explained in connection with the accompanying drawings, in which:

Fig. 1 is a view in elevation of a distilling apparatus embodying the preferred form of the invention;

.Fig. 2 is a plan view of the apparatus shown in Fig. 1; I

Fig. 3 is a vertical section of the fractionating or bubbling tower of the apparatus;

Fig. 4 is a sectionalview taken on the line 4-4 of Fig. 3;

Fig. 5 is a sectional view taken on the line 5-5 of Fig. 3, and

Fig. 6 is a sectional view taken on the line 66 of Fig. 3.

Oil to be distilled is passed from storage or othersource through a pipe 10 having a valve 12. therein into the first still 14' I of a series of stills of the usual form of continuousstills which are heated'by furnace gases or in any other desired manner. The stills are arranged preferably at successivel lower levels in the series to permit'oil to ow by gravity through the series. A portion of the oil is distilled in the first still 14, the vapors thereof passing through a vapor drum 16 to a vapor pipe 18 which leads. to a water cooled condenser or other condensing means in which the vapor fractionis condensed. The first vapor fraction obtained from the oil consists of gasoline or other light vapors, the composition of which may be controlled by the rate of admission of oil and the rate of firing. It is desirable to maintain the temperature of the vapors from the still 14 at substantially 350 F. to obtain the proper, vapor out. If

' desired, the oil passing to the still 14 may be preheated by passing the incoming oil through a series ofheat interchangers' 100, 110, 118 and 73 which will be further described in connection with the operation of the apparatus. The oil which remains un-- distilled in the still 14 passes by means of pipe 20 having valves 22 and 24 therein to' a still 26, in which the oil is heated to, a

higher temperature, preferably in the neighborhood of 400: F. In the still 26 a second vapor fraction is withdrawn from the oil which passes through a vapor dome 28 to a pipe 30 and from thence into a fractionating tower 32. The oil remaining undisz tilled in the still 26 passes-through a pipe 34, having valves 36 and 38 therein, to a still 40 similar to stills 14 and 26 in which the oil becomes still further heated to release another vapor fraction. Vapors which are evolved in the still 40 pass through a dome 42 to a pipe 44 leading to the fractionating tower 32 at a point considerably below the point at which pipe 30 is connected therewith. The "vapors passing through the pipe 44 are at a temperature considerably higher than those passing" through the pipe 30, the firing of the still being regulated so that a vapor temperature of substantially 450 F. may be maintained. The oil which remains unvaporized inthe still 40 passes through a pipe 46 having valves 48 and 50 therein to a still 52, in which the oil becomes further heated .and the vapors liberated therefrom attain a temperature of substantially 500 F. The

66 to a pipe 68 leading to fractionating tower 32 at the bottom thereof. The vapors in the still 64 attain ordinarily a temperature in the neighborhood of 550 F. but the temperature may vary widely with different oils. The portion of the oil remaining undistilled in still 64 passes through an exit pipe 7 0 having a valve 72 therein, and may be then passed through heat interchanger 73 for preheating oil advancing to the still, 14.

The fractiona-ting tower 32 makes use of the reboiling features of the ordinary bubbling type tower but is constructed in a manner such that anew principle of operation is involved in the fractional distillation of vapors. The tower is made up of a mber of sections co responding to the num er of stills in the series of stills from which vapors are passed to the fractionating tower. The lowest boiling point vapors to be passed to the tower are conducted from the still'26 through the pipe 30 to the lower portion of the upper section or gasoline section of the tower. In each of the sections there are a series of plates 82'(Fig. 3) which have a series of pipes 84 extending upwardly to permit vapors to pass through the plates. Over the top of the upwar dly extending I on - wardly through caps 86, by means of which vapors passing through the pipes are forced to pass beneath the surface of liquid on the plates during the passage of the vapors upwardly through the tower. Extending through each plate'is an overflow pipe 88 through pipes 8-1 are bubbling the tower from one plate to the next. At the top of the tower is a cooling-coil 90 which is supplied with water or other cooling-liquid for the purpose of condensing out higher boiling vapor constituents to accurately control the boiling point of the vapor fraction passing from the top section of the tower. The uncondensed gases and vapors which leave the top of the tower 32 pass through an outlet pipe 91 to a condenser '92 where the condensible vapors are recovered. The condensate recovered in the condenser 92 consists of high gravity high test gasoline which may be blended with other gasoline to make motor fuel.

The vapors passing through the upper or gasoline section consist of the vapors which are introduced throu h the inlet pipe 30, and the vapors passing t rough the'plate 82 immediately below the disch'arge'end of pipe 30 at the bottom of the gasoline section. A coil 93 is placed in the bottom compartmentof the gasoline section in which may be circulated water, able cooling medium to condense the higher boiling point portions in the vapors and permit only the lower boiling .point vapors to pass into the second compartment of the gasoline section.

through the gasoline section they pass through densates which. have progressive y lower boilin points. These bodies are constantly boile and reboiled or evaporated and recondensed'by means of the vapors, and the boiling points of the bodies of liquid in each compartment become subin the degree of their boiling points. The

higher boiling point liqui through the compartments so that the, high- 'est boiling fraction is at the bottom. The

fraction reaching the bottom of the gasoline section is a gasoline product having a comparatively high end point whichis suitable for blending-with other lower boiling point gasoline to form a motor fuel. This heavy gasoline or low end point naphtha may be drawn through an. outlet pipe 94, passed through a valve Y96 and trap 98, and conducted to a heat interchanger 100, by which it may be cooled and at the same time used to preheat the fresh oi'l advancing to the still 14. The cooled'condensate passing will then be By use of point of the through the interchanger 100 conducted to suitable storage. therefluxing coil 93 the boiling which liquid passes down-- oil, or any des1'r- As the vapors pass up.

a series of bodies of liquid con-.

latent heat in the scribed in connection wit ds work down ,oil in the bottom compartment of the gasoline section may be accurately controlled. To assist the control of the boiling point of the gasoline and the withdrawal through the trap 98, a valve 101 is placed in the overpi e 102, leading from the bottom plate section into the upper compartment of the kerosene section.

Vapors from the still 40 in which the vaor fraction corresponding to kerosene is distilled from the oil, pass through the vapor dome 42 into the pipe 44, and from thence into the lower portion of the second or kerosene section of the tower which has substantially the same construction as the firstor upper section. The vapors pass upwardly through the plates in this section and encounter the ortion ofthe condensate from the first section which passes through the overflow pipe 102 having valve 101therein, and" downwardly through the plates of the second section. In ment of the second section and adjacent the inlet pipe 44 is a coil 103 similar to coils 90 and 93, by which vapors from the third section are cooled to condense. a portion of the vapors at this point'. The material which is condensed in the second or kerosene section is drawn off at the bottom plate of the compartment immediately below the discharge end of vapor inlet pipe 44, by means of apipe 104, havingra valve 106 and a liquid trap-108 therein. he liquid which is withdrawn through pipe 104 passes downwardly into the heat exchanger 110 from which it may be passed to a receiver or utilized as desired.

flov s of the gasoline higher boiling point fraction is distilled,

pass upwardly through a pipe 56 into the tower in the, lower portion of a third or gas oil section in which the vapors heavier than kerosene are condensed. The vapors assed into the third section travel upwardy through the plates and are condensed in the same manner as has the first and second' sections. In the lowest compartment of the third section is a coil 111, slmilar to coils 90 and 93, which is placed in prox-, imity to the incoming vapor pipe 56 leading to the section. The condensed portion .of the vapors to of the heavier lquids from the section above ass downwardly from one plate to the next 1n the gas oil section and finally pass to the compartmentimmediatel below the vapor outlet end of pipe 56, tom which the condensates are withdrawn through a pipe 112, which is provided with a valve 114 and a liquid trap 116. From the pipe 112 the liquid passes into a heat exchanger 118 to be cooled and passes from thence to storage.

- Va ors from-the last still 04 in the series pass y means of the pipe 68 to the bottom reviously been deether with a small portion the lowest compartlie of the tower into the lowest or fuel oil section thereof, in which the heaviest vapors are condensed. The vapors pass upwardly through the plates and are finally condensed or pass into the section above to unite with the lighter vapors therein. The condensed portion of the vapors passes downwardly from plate to plate through the overflow pipes of the section and is finally withdrawn from the tower by means of the pipe 120, having a valve 122 therein. The pipe 120 is connected to the last still in the series so that the portion condensed in the lowest sec tion of the tower may be redistilled to re move the lighter fractions thereof. If it is found to be desirable with a particular oil the pipe 120 may be connected directly to a heat interchanger and from thence to a stor' age receptacle instead of being redistilled as above described. The still bottoms are con-- tinuously withdrawn from still 64 through outlet 70 and heat inter-changer 73.

The oil which is to be treated in the apparatus above described is preferably preheated by passing the oil through the heat exchangers 100, 110, 118 and 73 in heat ex,- Change with distillates from the tower 32 and residue from the still 64. It is apparent that the distillates from the higher parts of the fractionating tower are at the lowest temperatures, and it is evident therefore to one skilled in the art that the oil to be preheated should be passed first through the heat exchangers at the lower temperatures.

It preferred therefore to pass the oil'first through the heat exchanger 100, through which condensate from the gasoline section 1s passed, and next through the heat exchanger ],10, through which condensate from the kerosene section is passed, then through the exchanger 118, through which condensate from the third section or heavy dis- ,tillate section is passed and finally through the residuum heat interchanger 73.

The course of the oil to be preheated by assing through said preheaters is indicated y arrows having a short line crossing the same, the inlet pipe leading from storage to the first heat exchanger 100 being indicated by numeral 11 and the pipe leading from the lastheat exchanger 73 to the still 14 being indicated by numeral 13.

With the construction outlined above two different types of distillation are brought .into combination. The first type involves the use of a set of five continuously operated fire stills in which a primary distillation is effected. I In each of the five stills a separate vapor product is removed and each of these products is introduced at different levels into a fractionating column still of the bubbling type. In the bubbling type column still a rectification of the vapors is carried on by which a large number of different condensates are produced and fromwhich dissuch as alcohol and water and acetone and] Water, in which a primary distillation or boiling or evaporation is carried out in a cylindrical still and the vapors passed up through one tall column. A fractionating column has been used to some extent for petroleum distillation but petroleum is not a binary mixture, on the contrary it is comprised of such a large number of different hydrocarbons that it has been necessary to use a large number of trays in a column still. Such a large column still, that is, containing from to trays or compartments, is very expensive and does not have a large capacity. In the place of having a large column still for each one of the continuous primary stills, applicant has obtained the same effect This column still is divided into sections and carries on the same type of concentration as would be carried out in the ordinary type of column still. In the applicant's process, however, the concentrated distillates do not flow-back to the primary still, but portions thereof are withdrawn while other portions remain in the column to aid in the rectification of the vapors conducted-from the by one column still.

primary stills. By this means applicant however,the boiling points of the various fractions are maintained substantially constant throughout the entire column still and the vapors from the various primary stills pass through the fractions having boiling llo points very close to the boiling point of the particular vapors. Furthermore, while obtaining the effect of a high column still applicants column still has an increased capacity because the light or lower boiling point vapors are introduced into the column still in the section in which the condensates have similar boiling points and therefore it is not necessary to tax the capacity of the still by putting the low boiling point vapors into the bottom of the and thus scrubbing these low boiling point still and requiring a them to pass entirely through the column;

- tions maybe made 1 Having thussetforth 45 ity of stills,

' umn,.

65 fractionating column,

' Laetitia i apors with a large number of condensate bodies of much higher temperature and boiling point.

In the claims the phrase distilling col- 5 umn of the bubbling type 1 duced thereinto or formed therein are caused to pass in contact with a series of bodies .of condensate of successively lower temperature and average boiling point, in each body of which portions of said vapors are con-. densed and portions of the condensate of the body are vaporized. It is not necessary that 'suchcolumns have-bubbling caps because.

many formsof bubbling type or columns are in common use.

It is contemplated that various modificain the process and apparatus of the present invention without dereboiling parting from thespirit or the scope ofthe invention as described- It is to be understood that the temperatures ot the vapors in the stills. in the series will vary with the character of the oiltreated and that the applicant does notlimit his invention to the temperatures as set forth.

is claimed as new is: 1

12'. In an oil distillation apparatus, a series ofstills, means for passing oil continuously in series through the'stills, a fractionating column containing a plurality of condenshav-,

the said stills, means connecting the stills ing means,- means for passing vapors in g' substantially diflerent boiling points fromv each still to ithe-column at different points corresponding to the temperature'of' I the vapors from each still, means in the col-- umn for drawing oif condensate therefrom at different heights and means for collecting the condensates therefrom. I 2.

means connecting the stills in series-to withdraw -oil from one still and pass it .tothe next in ating column, avapor. connection between each of the stills and the fractionating cols said vapor connections.

points, whereby diflerent boiling into said column said column at different vapors of substantlally points may be introduced at alevel correspondingto the relative boiling temperature of the vapor. from each of said stills, means for introducing oil into .the first .still in the series andmeans for withdrawing oil from the series.

3. In an oil distillation apparatus, a plurality of stills, means connecting the stills 1n series to' pass oil from one still to' another in series, a fractionating column, means connecting-the vapor space of each still with the the points of connec he invention,fwhat In an-oil distillation apparatus, a pluralthe series, a fractionleading into last still in the zones, withdrawing a tion between the stills and the column being at different levels 'on'the column corresponding to the boiling temperature of the vapors conducted from each still, a plurality of heat interchangers, means connecting the said column with the said heat interchangers to pass condensed vapor portions from the column to the interchangers, means for pass- 1ng oil to be distilled through the series of heat interchangers to the still first in the serles and means for withdrawing residual oil from the still last in the series.

4. In an oil distillation apparatus, a plurality of stills adapted to be maintained at .progresslvely mcreasing temperatures, means series to the uppermost vapor inlet in said Y a column, and means-for conducting vapors from each success ve still to a successlvely lower vapor inlet in saidcolumn whereby I said vapors are introduced into said column to the reat different levels correspondin the vapors spective boiling temperatures 0 from each of said stills. u 5. In an oil distillation apparatus,a plurality' of stills adapted to be maintained at progressively increasing temperatures, va-

por outlets in the stills, means for'heating to permit thepassage of oilin seri es through the stills, a series of heat interchangers,-

to the still ,first iin the series,

means for withdrawing residual oil from the still lastin the series, a fractionating column havingvapor inlets atdifierent vertical respective boiling temperatures of the vaand means for v pors from each of said stills, conducting condensate from the condensate outlets; in the column to the heat interchangers. v u g 6. A process of distilling oil comprising passing oil through a series of vaporizing tions of different boiling point from said zones, passing" vapors ,from the first zone into a condensing zone, passing the vapors from the remaining vaporizing" zones into different levels of an independent vapor outlets of series of vapor frac- 1 means fiorpassing oil-through the heat interc hangers vapors of different boiling points are intro-' duced into the said vapor separating and condensing zone at levels corresponding to the boiling temperature of the said vapors, the lighter vapors passing to the higher levels therein, condensing vapors in the separating and condensing zone, withdrawing condensate at different levels of the said separating and condensing zone, Withdrawing the uncondensed vapor portion from the separating and condensing zone and sepa rately condensing the condensible portion thereof. 8. A process of fractional distillation which comprises distilling oil in a series of bodies to separate a series of vapor fractions having differentboiling points, separately introducing the vapor fractions into a dis tilling column of the bubbling type at different'levels thereof to effect a further fractionation of said vapors, .and simultaneously withdrawing a series of fractional condensates of different boiling points from differ- 40 ent levels of the column. 9. A process of fractional distillation which comprises distilling oil in a series of bodies to separate a series of vapor fractions having different boilin points, separately introducing the vapor ractions into a distilling column of the bubbling type at different levels to effect a further fractionation thereof and simultaneously Withdrawing a condensate from the column adjacent the point of admission of each vapor fraction.

10. A process of fractional distillation which comprises distilling oil in a series of bodies to separate a series of vapor fractions having different boiling points, separately introducing the vapor fractions into a distilling column of the bubbling type at different levels, introducing a cooling medium into different levels of the column to reflux the vapors and simultaneously with- 60 drawing a series of fractional condensates C of different boiling fpoints from the column. 11. A process 0 fractional distillation which comprises advancing oil through a series of stills in succession, progressively 5 raising the temperature of the oil as it advances to separate a vapor fraction of difthe vapor fractions into a column still of the bubbling type at different levels, the boiling points of the fractions decreasing from the bottom to the top of the column.

13. A process of fractional distillation which comprises advancing oil through a series of stills in succession, progressively raising the temperature of the oil as it advances to separate vapor fractions of progressively higher boiling points, separately introducing the vapor fractions into different portions of a column still of the bubbling type to effect a further fractionation there of and separately and simultaneously removing fractional condensates from different levels of the column.

14:. A process of fractional distillation which comprises advancing oil through a series of stills in succession, progressively raising the temperature of the oil as it advances to separate a vapor fraction in each still, separately introducing the vapor fractions into different portions of a column still of the bubbling type, separately removing fractional condensates from different levels of the column and introducing a cooling medium into the column to reflux vapors adjacent the points of removal of the condensates.

15. A process-of fractionally distilling oil, which comprises continuously advancing crude oil through a series of stillsmaintained at progressively higher temperatures in the direction of flow of the oil whereby a series of vapor fractions having different boiling pointsare simultaneously produced, introducing the said vapors into a common rectifying column atdifl'erent levels correspondingto the relative boiling temperature of each fraction, the lower boiling vapors being introduced into the column at the highest level, subjecting each vapor fraction to rectification in said column in, a.

restricted zone, withdrawing a condensate from each zone and passing vapors remaining uncondensed in each zone into the zone next above. 7

16. A fractionating condenser having separate inlet openings for vapors of different boiling points at points in said condenser at which different temperatures are maintained.

17. The method of fractionally condensing a plurality of vapor streams, each of different average boiling point, which comprises introducing said vapor streams simultaneously into a single condenser stream at intervals therealong, said single stream being maintained at progressively lower temperatures from the first inlet to the, outlet opening.

18. The method of fractionally condensing a plurality of Vapor streams, each of different average boiling point, which comprises introducing said vapor streams simultaneously into a single vapor stream maintained at progressively lower temperatures from one end to the other at points having temperatures substantially proportional to the average boiling-point of each vapor stream.

19. In -an Oll distilling apparatus,a plurality of stills arranged in series, means for conducting oil through the stills in series, means for heating the stills to progressively higher temperatures in the direction of flow of oil therethrough whereby a series of vapor fractions having different boiling points are simultaneously produced, a vapor fractionating column, means for eonductmg vapors from the first still of the series and introducing them into the upper portion of said column, means for conducting vapors from each succeeding still of the series and for introducing, them into said column at successively lower levels whereby said vapors are introduced into said column at different levels corresponding to the boiling temperature of each fraction.

20. The process ofcondensing a plurality of vapor streams of different boiling point, which comprises introducing the said vapor streams simultaneously and separately into a vapor fractionating zone in which progressively decreasing temperatures are main tained in the direction of flow of vapors therethrough, the lower boiling point vapors being introduced into a portion of said zone in which the temperature is relatively low and the higher boiling point vapors being introduced into the highest temperature portion of said zone, and substantially separately rectifying the vapors of each stream in said zone.

21. A process of fractionally distilling oil, which comprises continuously advancing crude oil through a series of stills maintained at progressively higher temperatures in the direction of flow of the oil, whereby a series of vapor fractions having different boiling points are simultaneously produced, introducing the said Vapors int-0' a common rectifying column at different levels corresponding to the relative boiling temperature of each fraction, the lower boiling vapors being introduced into the column at the HENRY N. LYONS.

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