Salt drying process 3

Shown in FIG. 4 is one embodiment of a method of crude oil component separation of the present invention, which utilizes a steam recycling design crude oil distillation unit 50. The steam recycling design crude oil distillation unit 50 includesa distillation column 52 having a flash zone 54 and a bottom 56, a first HEN 58, a desalter 60, a second HEN 62, a furnace 64, a returning vapor stream 65 and a side-stripper 66 for removing kerosene from the distillation column 52, a returning vaporstream 67 and a side-stripper 68 for removing diesel from the distillation column 52, a returning vapor stream 69 and a side-stripper 70 for removing gas oil from the distillation column 52, and three pumparounds PA1 72, PA2 74 and PA3 76, which areprovided in a similar configuration and function in a similar manner as in the conventional crude distillation unit 10 of FIGS. 1 and 2. The method of the present invention is unique in that a hydrocarbon-rich steam 77 is withdrawn from the crude oildistillation column 52 below the flash zone 54 thereof and heat exchanged with cold crude oil or other cold fluid in a cooler 78 to condense hydrocarbons, thereby producing condensed oil 79 and a vapor stream 81. The condensed oil 79 and vapor stream 81are separated in a tank or drum 80. The condensed oil 79 may be used in this state, or it may be sent to a gas oil stripper (not shown) for further separation. The vapor stream 81 is passed through a compressor 82 to form vapor stream 81', and vaporstream 81' is heated in a heater 84 to form heated vapor stream 81'', which is combined with a stream of make-up steam 85 and enters the bottom 56 of the distillation column 52 as a stripping steam, as shown in FIG. 4. Alternatively, the vapor stream 81may be disposed of rather than sending it back to the column 52; this would eliminate the need for the compressor 82 and the heater 84 as well as the reinjection of stream 81'' into the column.

It is to be understood that the method of the present invention is not limited to the use of the compressor 82 to compress the vapor stream 81 coming from the separator tank or drum 80 in the specific location illustrated in FIG. 4. The purposeof such compressor 82 is to facilitate the reinjection of the vapor stream 81 in the column 52 after passing through the heater 84, and therefore the compressor 82 may be positioned at any location that will allow the compressor 82 to function inaccordance with the present invention. For example, the compressor 82 can also be located immediately after removal of the recirculating stream 77 from the column 52 and before injection thereof into the cooler 78.

It should be noted that the above-described invention is not limited to a method utilizing an atmospheric distillation unit, and that the steps of the method of the present invention can also be adapted for use in the separation of any othermixtures in a similar manner. It is within the skill of a person having ordinary skill in the art to utilize the method of the present invention with, for example but not by limitation, crude distillation, vacuum distillation, FCC main fractionation,and homogeneous organic mixture separation, wherein the mixtures include, but are not limited to, crude oil, synthetic crude oil, and vegetable oils, and wherein the separation may be, but not limited to, flashing or distillation.

While the above-described embodiment involves extraction of the steam rich stream 77 below the flash zone 54 of the distillation column 52, the steam rich stream 77 can be extracted at any position on the distillation column 52 above the flashzone 54 and still fall within the scope of the present invention.

The method of the present invention utilizing the steam recycling design crude oil distillation unit 50 results in a larger yield of gas-oil than the conventional or pre-flash design crude oil distillation units 10 and 10a of the prior art. Thetechnology illustrated in FIG. 4 can also be adapted to accommodate product specification needs. Whether the condensed hydrocarbon-rich liquid 79 from drum 80 is sent to an independent stripper for conditioning or is injected into some of the trays ofthe column 52 or into one of the side strippers 66, 68 or 70 of the distillation column 52, the net result is an increase of gas-oil yield without a reduction of the yield of any other products.

It is to be understood that the method of the present invention is not limited to the use of steam as described herein above, and that any other compound which can function in accordance with the present invention may be utilized in the method ofthe present invention. It is within the skill of a person of ordinary skill in the art to select compounds that may be utilized in the method of the present invention, and therefore such compounds or mixtures thereof are within the scope of the presentinvention. For example, hydrogen, nitrogen, carbon dioxide, methane, ethane, ethylene, propane, combinations or mixtures thereof or the like may all be utilized in any of the methods of the present invention described herein.

The present invention relies on the injection of steam or any other light gas in the bottom of the column and extracting a vapor stream rich in hydrocarbons below or at the flash zone to recover the hydrocarbons from the vapor stream. While oneembodiment has been described herein for recovering liquids and which illustrates the remaining vapor being recycled to the column, the invention is not limited to the recovery process described herein above, and other variants of the recovery process,whether requiring recycling or not, are within the scope of the method of the present invention. In addition, the embodiment described herein suggests that the condensed oil 79 can be sent to different places, such as back to a tray of the column 52 orto a side stripper, or that the condensed oil 79 can be further processed. Any variant of this arrangement also falls within the scope of the methods of the present invention.
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Further, it is to be understood that the present invention also encompasses reinjection of the vapor stream 81 separated from the oil condensate 79 in drum 80 (FIG. 4) anywhere in the column 52, above or below the flash zone 54, as well as notreinjecting the vapor stream at all.

FIG. 5 illustrates another embodiment of the method of crude oil separation of the present invention. The embodiment of the method of the present invention shown in FIG. 5 utilizes a crude oil distillation unit 50a having a steam recyclingdesign, which is constructed of similar components and in a similar manner as the steam recycling design crude oil distillation unit 50 illustrated in FIG. 4, except that in the steam recycling design crude oil distillation unit 50a, a vapor stream 77ais withdrawn from a flash zone 54a of a crude distillation column 52a and processed through a cooler 78a and a tank or drum 80a to separate and remove condensed oil 79a. The hydrocarbon-rich condensed oil 79a is then divided in a splitter 90, with oneportion 92 being sent for further processing and the other portion 94 being injected into a side-stripper 70a rather than back into the distillation column 52a. In this case, the vapor 81a separated from the condensed oil 79a in the tank or drum 80a isnot reinjected back into the column 52a but rather is either disposed of or processed elsewhere.

While FIG. 5 illustrates the injection of the portion 94 of the condensed oil 79a obtained from the vapor 77a from the flash zone 54a of the distillation column 52a into the side-stripper 70a, it is to be understood that the condensed oil 94obtained from the vapor 77a from the flash zone 54a of the distillation column 52a could be injected into either of the other side-strippers 66a or 68a, or into one of the trays 65a, 67a or 69a, or into any other trays of the distillation column 52a, orinto an independent side-stripper (not shown) for conditioning prior to recycling to the distillation column 52a. It should also be understood that the vapor 81a can be recycled to the column 52a in a similar manner as that shown for the vapor 81 inFIG. 4, with the variants being described herein before.

FIG. 6 illustrates yet another embodiment of the method of crude oil separation of the present invention utilizing a steam recycling design, in which the condensed oil obtained from the vapor stream from the flash is injected into other parts ofthe column. The embodiment of the method of the present invention shown in FIG. 6 utilizes a crude oil distillation unit 50b having a steam recycling design, which is constructed of similar components and in a similar manner as the steam recyclingdesign crude oil distillation unit 50 illustrated in FIG. 4, except that in the steam recycling design crude oil distillation unit 50b, a vapor stream 77b is withdrawn from a flash zone 54b of a crude distillation column 52b and processed through acooler 78b and a tank or drum 80b to separate and remove condensed oil 79b. The hydrocarbon-rich condensed oil 79b is then passed through a splitter 96 for separation into two portions wherein a first portion is sent for further processing and a secondportion is injected into the distillation column 52b at a position 86. In this case, the vapor stream 81b separated from the condensed oil 79b in the tank 80b is not recycled to the column 52b but rather is either disposed of or processed elsewhere.

While the position 86 is illustrated in FIG. 6 as being located between a tray 67a and an injection site 88 from a side-stripper 68a, it is to be understood that the position 86 may be located anywhere on the distillation column 52b, and that thelocation of position 86 in FIG. 6 is provided for illustration purposes only.

The key step to the embodiments of the present invention described herein above with reference to FIGS. 4 6 is related to the withdrawal of vapor from the distillation column (either below or even above the flash zone) and the removal of heavycomponents from such vapor. In the embodiments described herein, this is accomplished by the use of a cooler and a drum or flash tank, from which the condensate of heavy hydrocarbons is obtained. In addition, the vapor is either recompressed and sentto the column, disposed or of processed elsewhere, while the condensate may be used as is or sent back to the column or to a side-stripper.

Thus, the core of the invention is the use of a carrier component (such as steam or any component known to those of ordinary skill in the art) below the flash zone and the removal of the vapor to separate heavy condensates from it. Any method ofaccomplishing this step may be utilized in the method of the present invention. In addition, while the embodiments described herein above involve the destination of the condensate oil being the main column or one of the side strippers, there are manyother alternatives that also fall within the scope of the present invention. Such alternatives include, but are not limited to, splitting of the liquid stream to feed the main column at various locations, and the independent processing of the liquidstream all together.

Description of FIGS. 7 9

Another aspect of the method of the present invention involves the removal of intermediate components of the crude oil from the flash zone feed. FIG. 7 illustrates one embodiment of such a method of crude oil separation of the present inventionthat utilizes the carrier effect of light crude components. The method utilizes a crude oil distillation unit 100, in which the crude oil is heated to a predetermined temperature in a furnace 101, where a portion of the crude oil vaporizes. Thepartially vaporized crude oil passes through a flash tank or drum 102, where vapor (I) and liquid (II) are separated. The vapor (I) is cooled in a cooler 104 and then enters another flash tank or drum 106, where the condensate (III) and the remainingvapor (IV) are separated. The condensate (III), consisting mostly of gas oil components, is sent to a main tower or atmospheric distillation column 108 at a tray 109 above a gas oil withdrawal tray 110; however, it is to be understood that thecondensate (III) comprising the intermediate components may be sent to the column 108 at any position on the column, and the tray 109 is illustrated as being above the gas oil withdrawal try 110 for the purpose of illustration only. The remaining vapor(IV) is mixed with the liquid (II) in a mixer 111, and the mixture is heated in a furnace 112 before entering a flash zone 114 of the main tower 108. While the side strippers, heat exchanger networks and pumparounds have been omitted from FIG. 7 for thepurpose of simplicity, it is within the skill of a person having ordinary skill in the art, given the present disclosure, to modify the crude oil distillation unit 100 to include side strippers and pumparounds (such as side strippers and pumparoundssimilar to those illustrated in FIGS. 1 4), and therefore such arrangement also falls within the scope of the present invention.
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The method of the present invention takes advantage of the carrier effect of light components. The compositions of these components vary with the temperature chosen in the two flash tanks 102 and 106 and the crude oil. The temperatures used canbe varied with different separation results. The separation of the intermediate components in the condensate (III) is responsible for the success of the method of the present invention. Whether the intermediate components are sent to the distillationcolumn 108 or to side-strippers into different trays (not shown), or into other units is a matter of design choice that is within the skill of a person of ordinary skill in the art, and therefore such adaptations of the methods described herein arewithin the scope of the present invention.

Any other alternative to the two-flash arrangement described herein above with reference to FIG. 7 that can accomplish the separation of the intermediate components leaving a portion of lights mixed with the crude fed into the flash zone alsofalls within the scope of the method of the present invention. Such alternatives can comprise, for example, the use of multiple flashes and/or other separation units such as distillation columns to send different portions of intermediates to differentlocations.

Indeed, such alternatives include, but are not limited to, change of tray location for the feed of intermediates into the column or into the side stripper, splitting the feed of intermediates to feed various locations or simply use of the feed ofintermediates in some other units, the use of more than one flash with alternative locations of the column feeds/side-strippers or possible use in other units, the use of distillation columns, and the like.

Shown in FIG. 8 is another embodiment of the method of crude oil separation of the present invention, which utilizes a crude oil distillation unit 100a. The crude oil distillation unit 100a is constructed from similar components and in a similarmanner as the crude oil distillation unit 100 of FIG. 7, except as described in more detail herein below. In the crude oil distillation unit 100a, crude oil is heated to a predetermined temperature in a furnace 101a, and a portion of the crude oilvaporizes. The partially vaporized crude oil passes through a flash tank or drum 102a, where vapor (I) and liquid (II) are separated. The vapor (I) is cooled in a cooler 104a and then enters another flash tank or drum 106a, where the condensate (III)and the remaining vapor (IV) are separated. In the embodiment of the method of the present invention shown in FIG. 8, the condensate (III) is split in a splitter 116 into stream portions (V), (VI), (VII), and (VIII), and at least one of the streamportions (V), (VI), (VII), or (VIII) from the split condensate (III) is introduced into a main tower or atmospheric distillation column 108a at a position above a gas oil withdrawal tray 110a. In FIG. 8, stream portion (V) is introduced into thedistillation column 108a through tray 109a at a position above the gas oil withdrawal tray 110a, while stream portion (VI) is introduced into the distillation column 108a through tray 109a' at a position above the gas oil withdrawal tray 110a. It is tobe understood that the trays 109a and 109a' are illustrated as being located above the gas oil withdrawal tray 110a for the purposes of illustration only, and that the trays 109a and 109a' may be located at any position on the column 108a. Likewise,while the steam portion (VII) is illustrated as being sent to the gas oil side-stripper 118, it is to be understood that the steam portion may be introduced into any side stripper disclosed herein. FIG. 8 also illustrates the stream portion (VII) beingintroduced into a gas-oil side stripper 118, while stream portion (VIII) is illustrated as being sent elsewhere for further processing.

The remaining vapor (IV) from the flash tank 106a is mixed with the liquid (II) from the flash tank 102a in a mixer 111a, and the mixture is heated in a furnace 112a before entering a flash zone 114a of the distillation column 108a.

Shown in FIG. 9 is yet another embodiment of the method of crude oil separation of the present invention, which utilizes a crude oil distillation unit 10b. The crude oil distillation unit 100b is constructed from similar components and in asimilar manner as the crude oil distillation unit 100 of FIG. 7, except as described in more detail herein below. In the crude oil distillation unit 100b, crude oil is heated to a predetermined temperature in a furnace 101b, and a portion of the crudeoil vaporizes. The partially vaporized crude oil passes through a flash tank or drum 102b, where vapor (I) and liquid (II) are separated. The vapor (I) is cooled in a cooler 104b and then enters another flash tank or drum 106b, where the condensate(III) and the remaining vapor (IV) are separated. The condensate (III) is introduced into a distillation column 108b at a tray 109b at a position above a gas oil withdrawal tray 110b. The remaining vapor (IV) is cooled in a cooler 130 and then entersyet another flash tank or drum 132, where vapor (IX) and liquid (X) fractions are separated. The liquid fraction (X) then enters the distillation column 108b at a tray 134 above the gas oil withdrawal tray 110b. The remaining vapor fraction (IX) fromthe flash tank 132 is mixed with the liquid (II) from the flash tank 102b in a mixer 111b, and the mixture is heated in a furnace 112b before entering a flash zone 114b of the main tower 108b. Variations of this process include providing multipleflashes or other units, changing the feed trays of liquid streams (II) and (X), and the like.

The key step to the embodiments of the present invention described herein above with reference to FIGS. 7 9 is related to the separation from the feed crude oil of components of intermediate molecular weight, such as components in the boilingpoint range of, but not limited to, diesel or gas oil, leaving the very heavy and very light portions together and injecting such mixture in the flash zone of the column. The removal of components of intermediate molecular weight allows a larger portionof the crude oil to vaporize in the flash zone of the main crude tower. In the embodiments described herein, this is accomplished by the use of two or more flash drums and their corresponding furnaces or coolers. However, any method of accomplishingthis step may be utilized in the method of the present invention. The flash drum can also be replaced by any other separation equipment known in the art that is capable of separating the feed into two streams: one rich in light components and the otherrich in heavy components. An example of such equipment that may be utilized in such a manner is a column with several trays. The stream temperature at the outlet of the cooler (such as cooler 104 in FIG. 7) is such that the vapor (I) entering thecooler 104 is partially condensed. In addition, the flashing/cooling process can be repeated and therefore is not limited to one flash drum followed by one cooler, such as the flash drum 102 followed by the cooler 104, as shown in FIG. 7. WWW.MZP66.BLOGFA.COM
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The separation of intermediate components can also be accomplished by other methods such as, but not limited to, distillation, absorption, adsorption, membrane separation and combinations thereof.

In addition, while the embodiments provided herein above describe the destination of the intermediate components as being the main column, there are many other alternatives that also fall within the scope of the present invention. Suchalternatives include, but are not limited to, splitting of the liquid streams to feed the main column at various locations, and the independent processing of the liquid streams all together.

While each of the embodiments described herein and illustrated in the drawings includes elements utilized in varying the temperature of a stream, for example, heat exchangers, furnaces, heaters and coolers, it is to be understood that any elementthat varies the temperature of the contents contained therein may be utilized in the methods of the present invention, and that such methods are not limited to the specific elements described herein and illustrated in the drawings. For example, the term"heater" may be used to describe a furnace, a heat exchanger, or a combination of the two, and such terms may be used interchangeably herein. Therefore, while a furnace may be illustrated in the figures, it is to be understood that a heat exchanger or acombination of a furnace and a heat exchanger, or any other form of heater known in the art may be substituted for the furnace illustrated herein and still fall within the scope of the present invention.

While the methods of the present invention have been described herein with respect to crude oil atmospheric distillation columns, it will be understood that the methods of the present invention are not limited to such use but can also be used toimprove the yield of distillates in crude oil vacuum columns or any other separations of mixtures in a similar manner, and it is within the skill of a person having ordinary skill in the art to recognize the separations to which the methods of thepresent invention can be applied and to adapt the methods of the present invention for use in such separations, which include, but are not limited to, crude distillation, vacuum distillation, FCC main fractionation, and homogeneous organic mixtureseparation, wherein the mixtures include, but are not limited to, crude oil, synthetic crude oil, and vegetable oils, and wherein the separation may be, but not limited to, flashing or distillation.

Changes may be made in the construction and the operation of the various components, elements and assemblies described herein or in the steps or the sequence of steps of the methods described herein without departing from the spirit and scope ofthe invention as defined in the following claims

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