Salt drying process2

54. A method of separating components of a crude oil comprising: providing a crude oil comprising naphtha, kerosene, diesel, gas oil and residue; separating the crude oil into a first stream composed substantially of intermediate molecularweight and/or intermediate boiling point components and a second stream composed substantially of light molecular weight and/or light boiling point and heavy molecular weight and/or high boiling point components; feeding the second stream into a flashzone of a column capable of separating the crude oil into a naphtha stream, a kerosene stream, a diesel stream and a gas oil stream, wherein the second stream is substantially free of intermediate molecular weight and/or intermediate boiling pointcomponents, thereby utilizing a carrier effect of light molecular weight and/or low boiling point components such that a larger portion of the heavy molecular weight and/or high boiling point components are vaporized in the flash zone of the column; andselectively withdrawing at least one of the naphtha stream, the kerosene stream, the diesel stream and the gas oil stream such that energy consumption is decreased.

55. A method of separating components of a mixture comprising: providing a crude oil comprising naphtha, kerosene, diesel, gas oil and residue; separating the crude oil into a first stream rich in low molecular weight and/or low boiling pointcomponents, a second stream rich in heavy molecular weight and/or high boiling point components, and a third stream rich in intermediate molecular weight and/or intermediate boiling point components; feeding the first, second and third streams into acolumn such that the first stream is fed into a first position on the column, the second stream is fed into a second position on the column, and the third stream is fed into a third position on the column, wherein the first and second positions are in aflash zone of the column, and wherein the third position is in a location different from the flash zone of the column, thereby utilizing a carrier effect of light molecular weight and/or low boiling point components such that a larger portion of theheavy molecular weight and/or high boiling point components are vaporized in the flash zone of the column, and wherein the column is capable of separating the crude oil into a naphtha stream, a kerosene stream, a diesel stream and a gas oil stream; andselectively withdrawing at least one of the naphtha stream, the kerosene stream, the diesel stream and the gas oil stream from the column such that energy consumption is decreased.

56. A method of separating components of crude oil comprising: providing crude oil comprising naphtha, kerosene, diesel, gas oil and residue; heating the crude oil to a temperature sufficient to permit separation of the crude oil into a vaporstream and a liquid stream; feeding the heated crude oil to a first flash drum and separating the crude oil into the vapor stream and the liquid stream; cooling the vapor stream and feeding the cooled vapor stream to a second flash drum to separate thevapor stream into condensate and a remaining vapor stream, wherein the condensate comprises gas oil components and the remaining vapor stream comprises light components; feeding the condensate into a distillation column whereby the column is capable ofseparating the crude oil into a naphtha stream, a kerosene stream, a diesel stream and a gas oil stream, the condensate being fed into the distillation column above a flash zone of the distillation column; mixing the liquid stream from the first flashdrum and the remaining vapor stream from the second flash drum to provide a mixture and heating the mixture; feeding the mixture into the flash zone of the distillation column; and selectively withdrawing at least one of the naphtha stream, thekerosene stream, the diesel stream and the gas oil stream from the column such that energy consumption is decreased.

57. A method of separating components of crude oil comprising: providing crude oil comprising naphtha, kerosene, diesel, gas oil and residue; heating the crude oil to a temperature sufficient to permit separation of the crude oil into a vaporstream and a liquid stream; feeding the heated crude oil to a first flash drum and separating the crude oil into the vapor stream and the liquid stream; cooling the vapor stream and feeding the cooled vapor stream to a second flash drum to separate thevapor stream into condensate and a remaining vapor stream, wherein the condensate comprises gas oil components and the remaining vapor stream comprises light components; feeding the condensate into a distillation column whereby the column is capable ofseparating the crude oil into a naphtha stream, a kerosene stream, a diesel stream and a gas oil stream, the condensate being fed into the distillation column above a flash zone of the column; cooling the remaining vapor stream from the second flashdrum and feeding the cooled remaining vapor stream to a third flash drum to further separate the cooled remaining vapor stream into a residual vapor stream and a residual liquid stream; feeding the residual liquid stream from the third flash drum intothe distillation column above the flash zone of the column; mixing the liquid stream from the first flash drum and the residual vapor stream from the third flash drum to form a mixture and heating the mixture; feeding the mixture into the flash zone ofthe distillation column; and selectively withdrawing at least one of the naphtha stream, the kerosene stream, the diesel stream and the gas oil stream such that energy consumption is decreased.

Description

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STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

BACKGROUND OF THE INVENTION

Crude oil distillation is used to separate petroleum crude into several products, including naphtha, kerosene, diesel and gas oil, for example. Such products of crude oil distillates may either be sent out as final products or may be furtherprocessed. Crude oil distillation is not only an indispensable unit in a refinery but is also the largest unit among all petroleum or chemical processing units. One of the major objectives of crude oil distillation design and operation is to increasethe amount of distillate products, because the distillate products are much more valuable than the residue. However, the yield of distillates is limited by the allowable maximum temperature, above which substantial thermal cracking takes place, therebyresulting in loss of product and fouling of equipment.

In an atmospheric-vacuum distillation system with both atmospheric tower and vacuum tower, it is economically desirable to increase the amount of atmospheric distillates and reduce the atmospheric residue, which feeds the vacuum tower. On thebasis of one barrel distillate product, vacuum distillation requires extra energy to maintain a vacuum system. Energy is required to remove leaked air, non-condensables in the oil and light olefins formed by thermal cracking. On the basis of the samecapacity, a vacuum tower would be much larger in size and therefore more expensive because one pound of vaporized oil at 10 mmHg absolute pressure requires a space about 70 times larger than that required at atmospheric pressure.

Therefore, there exists a need in the art for new and improved methods of crude oil separation that increase the yield of products such as diesel and gas oil and therefore overcome the disadvantages and defects of the prior art.

BRIEFDESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic representation illustrating a crude oil separation method utilizing a conventional crude oil distillation unit of the prior art.

FIG. 2 is a schematic representation illustrating one embodiment of heat exchanger networks of the conventional crude oil distillation unit of FIG. 1 in detail.

FIG. 3 is a schematic representation illustrating a crude oil separation method utilizing a crude oil distillation unit having a preflash design of the prior art.

FIG. 4 is a schematic representation illustrating a crude oil separation method of the present invention utilizing a crude oil distillation unit having a steam recycling design constructed in accordance with the present invention.

FIG. 5 is a schematic representation of another embodiment of a crude oil separation method of the present invention utilizing a crude oil distillation unit having a steam recycling design constructed in accordance with the present invention.

FIG. 6 is a schematic representation of yet another embodiment of a crude oil separation method of the present invention utilizing a crude oil distillation unit having a steam recycling design constructed in accordance with the present invention.

FIG. 7 is a schematic representation of yet another embodiment of a crude oil separation method of the present invention.

FIG. 8 is a schematic representation of yet another embodiment of a crude oil separation method of the present invention.

FIG. 9 is a schematic representation of yet another embodiment of a crude oil separation method of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1 and 2 illustrate a method of crude oil separation utilizing a conventional atmospheric crude oil distillation unit 10 of the prior art. Proper separation of the crude oil into products by the conventional crude oil distillation unit 10requires the crude oil to be heated and partially vaporized before being fed into a distillation column 12 of the conventional crude oil distillation unit 10. Crude oil contains salts which can be harmful to downstream equipment and must be removed. Toremove the salts, water is mixed with the crude oil and typically heated to temperatures between about 220° F. to about 280° F. To achieve these temperatures, the crude is first heated up by exchanging heat with product streams and/orpumparound streams in a heat exchanger network (HEN). An example of such an HEN is illustrated in detail in FIG. 2 as well as indicated schematically by a circle and the reference numeral 14 in FIG. 1. Once heated up, the mixture enters a unit called adesalter 16. Water containing the salts is removed in the desalter 16, and the salt-free crude oil is further heated up in a second heat exchanger network (HEN) 18. Since the amount of heat available from products coming from the distillation column 12is not enough to heat the crude oil in the second HEN 18 to its desired temperature, a furnace 20 is used to assist the crude oil in achieving the desired high temperature (typically between about 650° F. to about 700° F. The distillationcolumn 12 of the prior art conventional crude oil distillation unit 10 is a device that places crude vapors in contact with liquids in a countercurrent fashion. The partially vaporized crude from the furnace 20 is fed into a flash zone 22 of theatmospheric distillation column 12, where the vapor and liquid separate. The vapor includes all the components that comprise the products (such as naphtha, kerosene, diesel and gas oil), while the liquid contains residue and a small amount of relativelylight components in the range of gas oil. These components are also removed from the residue by steam injection 33 at a bottom 24 of the distillation column 12. As the crude vapors rise, their contact with liquid causes it to change its composition. The descending liquid also changes its composition, so that at different stages, liquid is extracted from trays and sent to units called side-strippers (generally represented by the reference numerals 27, 29 and 31 in FIG. 1) in which final conditioningof the products using steam takes place, while the vapors are stripped and the steam returned to the column through streams 26, 28 and 30. In addition, to more effectively remove heat, liquid is extracted at various points in the distillation column 12and cooled down for reinjection at a different position on the column. These heat removal devices (heat exchangers) are indicated schematically as PA1, PA2 and PA3 in FIG. 1 as a circle with an arrow and generally represented by the reference numerals32, 34 and 36, respectively, and are referred to as pumparounds in the petroleum refining jargon. Cooling water can be used in the heat exchangers PA1 32, PA2 34 and PA3 36, but it is always more advantageous to have these streams release their heat tothe raw crude oil in the heat exchanger networks (HEN) 14 and 18. FIG. 2 illustrates one embodiment of the prior art conventional crude oil distillation unit 10 with real connections of the heat exchanger networks 14 and 18 consisting of heat exchangersbetween the crude and the products from the side-strippers 27, 29 and 31 and the pumparounds PA1 32, PA2 34 and PA3. Although it is not indicated in the figure, the condenser is also used to heat up the crude, typically as part of the heat exchangernetwork 14 of FIG. 1. Several different designs and configurations for such connections in the conventional crude oil distillation unit 10 are possible, of which the one shown in FIG. 2 is just an example. For example, it is often found that the crudeis split into two or more streams, which are heated by products and pumparound streams, and these streams merge again before entering into the desalter. The stream that leaves the desalter very often is also split to exchange heat and merge beforeentering into the furnace. In addition, in other prior art crude oil distillation units, gas oil is not produced and instead becomes part of the residue. Such prior art crude oil distillation units contain one less side-stripper and one less pumparoundthan that shown in FIGS. 1 and 2. Further, in prior art crude oil distillation units in which gas oil is not produced, the diesel may be further separated into heavy and light diesel.

In summary, in the conventional crude oil distillation unit 10 of the prior art (FIGS. 1 and 2), crude oil is heated to a predetermined temperature and fed into the main distillation column 12 in a region called the flash zone 22, where theresulting vapor and residue are separated. The vapor rises towards the top of the crude oil distillation column 12 and is put in contact with descending liquid reflux streams, such as the return streams of the pumparounds and the top naptha reflux. Side products are withdrawn at different positions based on the temperature of the distillation column 12 at the particular position. Further, in the case of atmospheric distillation, conditioning of these side products takes place in separate steamstrippers 27, 29 and 31. In the case of vacuum distillation, for example, side strippers are not used. The resulting residue stream 35 is stripped with steam 33 in the bottom section 24 of the distillation column 12, called the stripping section, torecover light components.

Because the value of residue 35 is lower than that of other products, it is economically desirable to produce more distillate products and decrease the yield of residue. To achieve this objective, a large amount of steam 33 is injected at thebottom 24 of the distillation column 12 to strip light components (mainly gas oil components) from the residue 35. Steam injection is limited by water saturation of the plates of the distillation column 12. The injection of a large amount of steam 33results in higher steam consumption and larger cooling duties. Once the crude is processed in the atmospheric distillation column 12, the residue stream 35 (FIG. 1) is usually sent to a vacuum distillation column.

Other examples of prior art crude oil distillation unit designs include a crude oil distillation unit 10a having a pre-flash design (as illustrated in FIG. 3) and a crude oil distillation unit having a pre-fractionation design (not shown). Pre-flash and pre-fractionation designs of crude oil distillation units are constructed from similar components and in a similar fashion as the crude oil distillation unit 10 described herein before, but differ from conventional designs in that someseparation of light gasoline is performed at lower temperatures. The pre-flash design crude oil distillation unit 10a utilizes a device called a flash unit 38, and a top product from the flash unit 38 (labeled "vapor" in FIG. 3) is injected into anatmospheric distillation column 12a of the pre-flash design crude oil distillation unit 10a. In a pre-fractionation design crude oil distillation unit (not shown), a conventional distillation column is used upstream of the furnace and main column toseparate light components, and a top product of light components from the column has commercial value and is sent to storage. Several variations of these arrangements of crude oil distillation units are currently used in practice. Including a flashunit or a pre-fractionation column upstream of the atmospheric distillation column removes most of the light components present in the crude oil charge, thereby reducing the load on the atmospheric distillation column.

The present invention is directed to a method for increasing the yields of diesel and gas oil in crude oil distillation while reducing steam consumption and residue yield. In the prior art, this was accomplished by increasing the steam injection33 into the crude oil distillation unit 10 (FIG. 1). In the present invention, a hydrocarbon-rich mixture containing steam is extracted below the flash zone. This stream is cooled down, and the liquid is separated, while the vapor is eventuallyrecycled to the column. In another embodiment of the present invention, the bulk of the components that are targeted for separation from the residue in the flash zone are separated before injecting the crude into the column, as will be described in moredetail herein after.

The present invention is also directed to methods of separating other mixtures, such as, but not limited to, vegetables oils, mixtures of aromatics, synthetic crude or mixtures of hydrocarbons coming from catalytic crackers, and the like. Oneembodiment of the present invention includes a method of separating components of a mixture that includes at least a first component having light molecular weight and/or low boiling point and a second component having heavy molecular weight and/or highboiling point. The mixture may further include one or more additional components of varying intermediate molecular weights and/or intermediate boiling points. A mixture containing a first component, a second component and an intermediate component isdescribed herein for the purpose of example only. In the case of crude oil, one can consider the first component to be composed of naphtha, kerosene and diesel, the second component to be composed of residue and one intermediate component to be composedof gas oil. However, in certain circumstances where the gas oil is not separated, the light or first component can be composed of naphtha and kerosene, the second component composed of residue and gas oil, and the intermediate component composed ofdiesel.

The mixture is heated to a temperature sufficient to permit separation of the mixture into a first stream rich in the first component and a second stream rich in the intermediate component whereby, upon passage of the mixture through a column,the column is capable of separating the mixture into the first stream rich in the first component and the second stream rich in the intermediate component, thereby leaving a heavy residue in a bottom of the column, wherein the heavy residue is rich inthe second component. The temperature to which the mixture is heated will vary depending upon the contents of the mixture. However, the temperature to which the mixture is heated must be sufficient to permit separation of the mixture into streams richin the separate components upon passage through a column. In the case of crude oil, the temperatures that may be used in accordance with the present invention include a range of from about 500° F. to about 800° F. For other mixtures,these ranges of temperatures vary according to the boiling points of the light and heaviest compounds of the mixture.

The heated mixture is then fed into a column having a flash zone, such as an atmospheric distillation or a vacuum column in petroleum fractionation. A vapor stream is then withdrawn from the column at a position below the flash zone of thecolumn, and the vapor stream is cooled and separated into a condensate and a resultant vapor stream. Following this step, at least one of the resultant vapor stream and the condensate is recycled to the column. If the resultant vapor stream is recycledto the column, the resultant vapor stream may be heated and/or recompressed prior to recycling the resultant vapor stream into the column. If the condensate is recycled to the column, rather than feeding the condensate directly into the column, thecondensate may be introduced into a side-stripper that feeds into the column. It also may be necessary to add an additional non-condensable or condensable compound or mixture of compounds in small amounts at the temperature of the flash zone and/orbelow the temperature of the flash zone. Such non-condensable or partially condensable compound or mixture of compounds is then eventually recycled as a vapor back to the column. Examples of non-condensable compounds for the case of crude distillationare, but are not limited to, methane, nitrogen, carbon dioxide, light hydrocarbon gases and the like.

In the final step of the method of the present invention, at least one of the first stream rich in the first component and the second stream rich in the intermediate component is selectively withdrawn from the column such that the yield of atleast one of the first and intermediate components is increased and the yield of residue is decreased.

One mixture that may be separated by the method described herein above is crude oil, wherein the crude oil comprises naphtha, kerosene, diesel, gas oil and residue. In one such method, the crude oil is heated to a temperature sufficient topermit separation of the crude oil into a naphtha stream, a kerosene stream, a diesel stream and a gas oil stream upon passage through a column. Such temperatures are well known to a person of ordinary skill in the art and may vary depending upon theparticular composition of the crude oil. However, generally the temperature utilized in the method of the present invention will be in a range of from about 300° F. to about 1000° F. In the final step of the method of the presentinvention, at least one of the naphtha stream, the kerosene stream, the diesel stream and the gas oil stream is selectively withdrawn from the column such that the yield of at least one of naphtha, kerosene, diesel and gas oil is increased and residueyield is decreased.

In another method of separating components of crude oil, the crude oil is heated to a temperature sufficient to permit separation of the crude oil into a naphtha stream, a kerosene stream, a diesel stream and a gas oil stream upon passage througha column. Columns and heating temperatures that may be utilized in accordance with the present invention have been described herein above. The heated crude oil is then fed to the column, and a vapor stream is withdrawn from the column at a positionbelow the flash zone of the column. The vapor stream is then separated into a condensate of heavy components and a resultant vapor stream, such as by cooling the vapor stream to form a condensate and separating the resultant vapor stream from thecondensate. The condensate of heavy components may then be recycled either directly to the column or to a side-stripper that feeds the column. The resultant vapor stream may be disposed of or further processed. In the final step, at least one of thenaphtha stream, the kerosene stream, the diesel stream and the gas oil stream is selectively withdrawn from the column such that the yield of at least one of naphtha, kerosene, diesel and gas oil is increased and residue yield is decreased.

In another embodiment of the present invention, an initial mixture containing at least one component having light molecular weight and/or low boiling point, at least one component having heavy molecular weight and/or high boiling point, and atleast one component having intermediate molecular weight and/or intermediate boiling point is separated. In the case of crude oil, the light molecular weight component can be considered as composed of kerosene and diesel oil, the heavy molecular weightcomponent as composed of residue and the intermediate molecular weight component as composed of gas oil. The method involves separating the initial mixture into two streams, a first stream composed substantially of components of intermediate molecularweight and/or intermediate boiling point and a second stream composed substantially of light molecular weight and/or low boiling point and heavy molecular weight and/or high boiling point components, and feeding the second stream into a column in theflash zone as described herein above. The first stream composed substantially of components of intermediate molecular weight and/or intermediate boiling point may also be fed into the column, and when fed into the column, the first stream is fed intothe column at a different location than the location at which the second stream is fed into the column.

In the final step, at least one light molecular weight and/or low boiling point component stream, at least one intermediate molecular weight and/or intermediate boiling point component stream or at least one heavy molecular weight or high boilingpoint component stream is selectively withdrawn from the column such that the yield of individual components of the initial mixture is increased. The initial mixture may include at least two individual components having light, heavy or intermediatemolecular weight and/or low, high or intermediate boiling point, respectively, and when the initial mixture includes two components having similar molecular weights and/or boiling points, the final step will include selectively withdrawing at least afirst light/heavy/intermediate molecular weight and/or low/high/intermediate boiling point component stream and a second light/heavy/intermediate molecular weight and/or low/high/intermediate boiling point component stream from the column.

Alternatively, rather than separating the first stream composed substantially of components of intermediate molecular weight and/or intermediate boiling point from the initial mixture to leave the second stream composed substantially of light andheavy molecular weight and/or low and high boiling point components to be fed into the column together, the initial mixture may be separated into a first stream rich in light molecular weight and/or low boiling point components, a second stream rich inheavy molecular weight and/or high boiling point components, and a third stream rich in intermediate molecular weight and/or intermediate boiling point components, and each of the streams are fed into a column as described herein above and capable ofseparating the initial mixture into at least one stream composed substantially of one individual light molecular weight and/or low boiling point component, at least one stream composed substantially of one individual intermediate molecular weight and/orintermediate boiling point component, and at least one stream composed substantially of one individual heavy molecular weight and/or high boiling point component. The first stream is fed into a first position on the column, the second stream is fed intoa second position on the column, and the third stream is fed into a third position on the column. In one embodiment, the first, second and third positions are at different locations on the column.
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A similar method to the method of separating the three components described in the paragraph above may be utilized, except that the liquid stream composed of substantially heavy molecular weight and/or high boiling point components from the firstflash drum is not mixed with the remaining vapor stream composed of substantially light molecular weight and/or low boiling point components from the second flash drum, thereby providing the three separate streams rich in light, heavy or intermediatemolecular weight and/or low, high or intermediate boiling point components.

The step of separating the initial mixture into the first, second and third streams may include heating the initial mixture to a temperature sufficient to permit separation of the initial mixture into a liquid stream and a vapor stream andfeeding the heated initial mixture to a first flash drum to separate the initial mixture into the vapor stream composed substantially of light and intermediate molecular weight and/or low and intermediate boiling point components and the liquid streamcomposed substantially of heavy molecular weight and/or high boiling point components (i.e., the second stream). The vapor stream is then cooled and fed to a second flash drum to separate a condensate stream composed substantially of intermediatemolecular weight and/or intermediate boiling point components (i.e., the third stream) and a remaining vapor stream composed substantially of light molecular weight and/or low boiling point components (i.e., the first stream). Then, the liquid streamcomposed substantially of heavy molecular weight and/or high boiling point components from the first flash drum (i.e., the second stream) is combined with the remaining vapor stream composed substantially of light molecular weight and/or low boilingpoint components from the second flash drum (i.e., the first stream) to provide a stream composed substantially of heavy and light molecular weight and/or high and low boiling point components.

One mixture that may be separated by the methods described herein above is crude oil comprising naphtha, kerosene, diesel, gas oil and residue. In the final step of the method, at least one of the naphtha stream, the kerosene stream, the dieselstream and the gas oil stream is selectively withdrawn from the column such that the yield of at least one of naphtha, kerosene, diesel and gas oil is increased and residue yield is decreased.

Yet another embodiment of the present invention is directed to a method of separating components of crude oil comprising naphtha, kerosene, diesel, gas oil and residue. The crude oil is heated to a temperature sufficient to permit separation ofthe crude oil into a vapor stream and a liquid stream, such as but not by way of limitation, a temperature in a range of from about 300° F. to about 1000° F., more preferably in a range of from about 400° F. to about 800° F., and most preferably in a range of from about 500° F. to about 700° F. The heated crude oil is then fed into a first flash drum that separates the crude oil into the vapor stream and the liquid stream. The vapor stream is then cooledand fed to a second flash drum to separate the vapor stream into condensate and a remaining vapor stream, wherein the condensate comprises gas oil components and the remaining vapor stream comprises light components. The condensate is then fed into acolumn capable of separating the crude oil into a naphtha stream, a kerosene stream, a diesel stream and a gas oil stream, such as a distillation or vacuum column. The condensate is fed into the column above the flash zone of the column. The liquidstream from the first flash drum and the remaining vapor stream from the second flash drum are mixed to provide a mixture, and the mixture is then heated and fed into the flash zone of the column. Finally, at least one of the naphtha stream, thekerosene stream, the diesel stream and the gas oil stream is selectively withdrawn from the column such that the yield of at least one of naphtha, kerosene, diesel and gas oil is increased and residue yield is decreased.

In an alternative of the method described immediately above, the condensate from the second flash drum may be split into at least two liquid streams prior to feeding the condensate into the column such that the at least two split liquid streamscontaining intermediate components are fed into the column at different locations of the column. The at least two split liquid streams may be fed directly into the column, or at least one of the split liquid streams may be fed into a side-stripper thatfeeds into the column. For example, one of the split liquid streams may be fed into a gas oil side-stripper, a diesel side-stripper, or a kerosene side-stripper that feeds into the column.

In another alternative of the method described immediately above, following passing of the condensate into the column, rather than mixing the liquid stream from the first flash drum and the remaining vapor stream from the second flash drum, theremaining vapor stream from the second flash drum is cooled and fed into a third flash drum to further separate the remaining cooled vapor stream into a residual vapor stream and a residual liquid stream. The residual liquid stream is then fed into thecolumn above the flash zone thereof, while the liquid stream separated from the crude oil in the first flash drum and the residual vapor stream separated from the remaining cooled vapor stream in the third flash drum are mixed to form a mixture that isthen heated and fed into the flash zone of the column. In the final step, at least one of the naphtha stream, the kerosene stream, the diesel stream and the gas oil stream is selectively withdrawn from the column such that the yield of at least one ofnaphtha, kerosene, diesel and gas oil is increased and residue yield is decreased. In all of the embodiments described herein, a flash drum has been used as a means of separating mixtures. However, it is to be understood that any other method known inthe art may be utilized to achieve the same or similar separation, and thus falls within the scope of the present invention.

While each of the embodiments described herein above is related to increasing yields of individual components of a mixture, such as increasing the yield of at least one of naphtha, kerosene, diesel and gas oil from crude oil, for example, it isto be understood that such embodiments may also be utilized to reduce energy consumption, even if the yield of individual components is not increased, and therefore decreasing energy consumption also falls within the scope of the methods of the presentinvention.

The embodiments of this invention are alternatives to traditional techniques for improving distillate yields such as inert gas injection or steam stripping, lowering the pressure of the flash zone or increasing the temperature of the crudeentering the flash zone. In fact, these embodiments can be applied in addition to the aforementioned techniques, thereby resulting in larger improvements. WWW.MZP66.BLOGFA.COM

Before explaining any of the above embodiments of the invention in greater detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of the components or steps ormethodologies set forth in the description or illustrated in the drawings. The invention is capable of other embodiments or of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology employedherein is for the purpose of description and should not be regarded as limiting.

The above-described embodiments of the methods of the present invention will now be described in more detail in relation to FIGS. 4 9.

Description of FIGS. 4 6