HYDROCARBON STREAM

FIELD

[0001] The field relates to a processes and apparatuses for producing naphtha. More particularly, the technical field relates to hydrocracking a blend of light cycle oil and kerosene to produce heavy naphtha.

BACKGROUND

[0002] Currently, there is an increasing trend worldwide towards moving from fuel mode to petrochemical mode. Refiners are tapping every opportunity to maximize the production of petrochemicals. One among them is to utilize the comparatively less valuable hydrocarbons or distressed hydrocarbons stream from the existing processes to produce petrochemicals. Refiners are striving to convert this range of hydrocarbons into valuable petrochemicals.

[0003] FCC technology is currently being employed in the refineries to upgrade the atmospheric and/or vacuum residue. However, FCC reactors, along with upgraded hydrocarbons, also produce some distressed streams such as light cycle oil (LCO). With increased use of FCC technology, the production of the distressed LCO stream is going to increase. Currently, LCO from FCC unit/reactor is sent to a diesel hydrotreating unit (DHT) as a blend with other diesel streams and thereafter hydrotreated to saturate the large amounts of aromatic species. However, this process consumes large amount of hydrogen to saturate the aromatics present therein. LCO comprises a large quantity of aromatics and thereby can be converted to valuable petrochemicals such as heavy naphtha.

[0004] Heavy naphtha is primarily used as a petrochemical feedstock for running the aromatic complexes and naphtha crackers and produce more valuable petrochemical products. However, as heavy naphtha demand is increasing, refiners are looking for alternative processes to obtain heavy naphtha from less valuable hydrocarbons to produce more valuable products. Integrated refineries with petrochemical complexes are increasingly looking at value addition in terms of olefins and aromatic yields that are obtained from a barrel of crude oil. [0005] Distressed LCO streams from FCC reactors comprising a large quantity of aromatics are an alternate option to produce more valuable products such as heavy naphtha. However, setting up a separate unit for producing heavy naphtha from distressed streams will require increased capital expenditure. Therefore, finding an economically viable process to produce heavy naphtha with desired amount of naphthenes and mono-aromatics from the distressed LCO stream remains a difficult task for the refiners.

[0006] Accordingly, it is desirable to provide new apparatuses and processes for converting the less valuable LCO streams into more valuable petrochemical feedstock.

Further, there is a need for an alternative approach to maximize the conversion of LCO to heavy naphtha with improved retention of naphthenes and mono-aromatics and which can be easily integrated with an existing hydroprocessing complex. Furthermore, other desirable features and characteristics of the present subject matter will become apparent from the subsequent detailed description of the subject matter and the appended claims, taken in conjunction with the accompanying drawings and this background of the subject matter. BRIEF SUMMARY

[0007] Various embodiments contemplated herein relate to processes and apparatuses for upgrading a hydrocarbon feedstock. The exemplary embodiments taught herein provide an integrated process for maximizing production of heavy naphtha and obtaining high cetane diesel. [0008] In accordance with an exemplary embodiment, a process is provided for maximizing production of heavy naphtha from a hydrocarbon stream, the process comprising providing a light cycle oil stream comprising mono-aromatics, di-aromatics and tri-aromatics to a hydrotreating reactor. The light cycle oil stream is hydrotreated in the presence of a first hydrogen stream and a hydrotreating catalyst in the hydrotreating reactor operating at hydrotreating conditions to saturate the di-aromatics and the tri-aromatics while minimizing the saturation of mono-aromatics and provide a hydrotreated effluent stream. Thereafter, at least a portion of the hydrotreated effluent stream and a kerosene stream are hydrocracked in a hydrocracking reactor operating at hydrocracking conditions comprising a hydrocracking pressure from 2758 kPa(g) (400 psig) to 10000 kPa(g) (1450 psig), or 2758 kPa(g) (400 psig) to 6000 kPa(g) (870 psig) and a hydrocracking temperature of 300°C to 400°C, or 320°C to 380°C in the presence of a second hydrogen stream and a hydrocracking catalyst to provide a hydrocracked effluent stream. At least a portion of the hydrocracked effluent stream is then fractionated to provide the heavy naphtha.

[0009] In accordance with another exemplary embodiment, a process for maximizing production of heavy naphtha from a hydrocarbon stream comprises providing a light cycle oil stream comprising mono-aromatics, di-aromatics and tri-aromatics to a hydrotreating reactor. The light cycle oil stream is then hydrotreated in the presence of a first hydrogen stream and a hydrotreating catalyst in the hydrotreating reactor operating at hydrotreating conditions to saturate the di-aromatics and the tri-aromatics while minimizing the saturation of mono- aromatics and provide a hydrotreated effluent stream. Thereafter, at least a portion of the hydrotreated effluent stream and a kerosene stream are hydrocracked in a hydrocracking reactor operating at hydrocracking conditions comprising a hydrocracking pressure from 2758 kPa(g) (400 psig) to 10000 kPa(g) (1450 psig), or 2758 kPa(g) (400 psig) to 6000 kPa(g) (870 psig) and a hydrocracking temperature of 300°C to 400°C, or 320°C to 380°C in the presence of a second hydrogen stream and a hydrocracking catalyst to provide a hydrocracked effluent stream. At least a portion of the hydrocracked effluent stream, is then fractionated to provide the heavy naphtha.

[0010] In accordance with yet another exemplary embodiment, a process for maximizing production of heavy naphtha from a hydrocarbon stream comprises providing a light cycle oil stream comprising mono-aromatics, di-aromatics and tri-aromatics to a hydrotreating reactor. The light cycle oil stream is hydrotreated in the presence of a first hydrogen stream and a hydrotreating catalyst in a hydrotreating reactor operating at hydrotreating conditions to saturate the di-aromatics and tri-aromatics while minimizing the saturation of mono aromatics and provide a hydrotreated effluent stream. Thereafter, at least a portion of the hydrotreated effluent stream and a kerosene stream are hydrocracked in a hydrocracking reactor operating at hydrocracking conditions in the presence of a second hydrogen stream and a hydrocracking catalyst to provide a hydrocracked effluent stream. The hydrocracked effluent stream is then passed to a first fractionation column to fractionate the hydrocracked effluent stream and to provide the heavy naphtha and an unconverted bottoms stream. The unconverted bottoms stream is passed to a second fractionation column to provide a kerosene fraction and diesel stream. The kerosene fraction from the second fractionation column is recycled to the hydrocracking reactor.

[0011] It is an advantage to operate the hydrotreating reactor at hydrotreating conditions to saturate the di-aromatics and tri-aromatics while minimizing the saturation of mono- aromatics, to maximize yield of heavy naphtha with improved retention of naphthenes and mono-aromatics. Further, the present disclosure provides an economically viable process by integrating hydrocracking a LCO hydrocracking process with a kerosene hydrocracking process to maximize production of heavy naphtha and obtaining high cetane diesel. The present process hydrotreats the LCO feed in presence of limited hydrogen presence in the hydrotreating reactor to the extent of converting di-aromatics and tri-aromatics present in LCO to mono-aromatics in hydrotreating reactor to further crack it in hydrocracking reactor to more valuable heavy naphtha rather than saturating all of mono-aromatics, di-aromatics, and tri-aromatics present in LCO in hydrotreating reactor for diesel blending and/or losing heavy naphtha selectivity in hydrocracking reactor. [0012] These and other features, aspects, and advantages of the present invention will become better understood upon consideration of the following detailed description, drawings and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The various embodiments will hereinafter be described in conjunction with the following FIGURES, wherein like numerals denote like elements.

[0014] FIG. l is a schematic diagram of a process and an apparatus for producing heavy naphtha in accordance with an exemplary embodiment. [0015] FIG. 2 is a schematic diagram of a process and an apparatus for producing heavy naphtha in accordance with another exemplary embodiment.

DEFINITIONS

[0016] As used herein, the term“stream” can include various hydrocarbon molecules and other substances.

[0017] As used herein, the term“column” means a distillation column or columns for separating one or more components of different volatilities. Unless otherwise indicated, each column includes a condenser on an overhead of the column to condense the overhead vapor and reflux a portion of an overhead stream back to the top of the column. Also included is a reboiler at a bottom of the column to vaporize and send a portion of a bottom stream back to the bottom of the column to supply fractionation energy. Feeds to the columns may be preheated. The top pressure is the pressure of the overhead vapor at the outlet of the column. The bottom temperature is the liquid bottom outlet temperature. Overhead lines and bottom lines refer to the net lines from the column downstream of the reflux or reboil to the column. Alternatively, a stripping stream may be used for heat input at the bottom of the column.

[0018] As used herein, the term“overhead stream” can mean a stream withdrawn in a line extending from or near a top of a vessel, such as a column.

[0019] As used herein, the term“bottoms stream” can mean a stream withdrawn in a line extending from or near a bottom of a vessel, such as a column. [0020] As used herein, the term“predominantly” can mean an amount of generally at least 50% or at least 75%, preferably 85%, and optimally 95%, by mole, of a compound or class of compounds in a stream.

[0021] As used herein, the term“rich” can mean an amount of generally at least 50% or at least 70%, preferably 90%, and optimally 95%, by mole, of a compound or class of compounds in a stream. Broadly, the term“rich” refers to the fact an outlet stream from a column has a greater percentage of a certain component that present in the inlet feed to the column. [0022] As used herein, the term“True Boiling Point” (TBP) means a test method for determining the boiling point of a material which corresponds to ASTM D2892 for the production of a liquefied gas, distillate fractions, and residuum of standardized quality on which analytical data can be obtained, and the determination of yields of the above fractions by both mass and volume from which a graph of temperature versus mass % distilled is produced using fifteen theoretical plates in a column with a 5: 1 reflux ratio.

[0023] As used herein, the term“T5” or“T95” means the temperature at which 5 volume percent or 95 volume percent, as the case may be, respectively, of the sample boils using TBP or ASTM D-86. [0024] As used herein, the term“heavy naphtha” means hydrocarbons boiling in the range using the True Boiling Point distillation method of T5 between 20°C (68°F) and l00°C (2l2°F), and T95 between l40°C (284°F) and l80°C (356°F).

[0025] As used herein, the term“kerosene” means hydrocarbons boiling in the range of between l32°C. and 300°C, using the True Boiling Point distillation method. Further, T5 boiling point for kerosene is from l20°C to 200°C and T95 boiling point is from 250°C to 300°C. As used herein, the term“separator” means a vessel which has an inlet and at least an overhead vapor outlet and a bottoms liquid outlet and may also have an aqueous stream outlet from a boot. The separator may be operated at higher pressure.

[0026] As used herein, the term“passing” includes“feeding” and“charging” and means that the material passes from a conduit or vessel to an object.

[0027] As used herein, the term“N + 2A” is taken as an index of reforming, wherein‘N’ denotes percentage of naphthenes and‘A’ denotes the percentage of mono-aromatics.

“N+2A” is calculated as the volume percent of naphthenes in the naphtha plus 2 times the volume of mono-aromatics. A feed having a higher concentration of N + 2A is a better- quality feed for producing high concentration of aromatics.

[0028] As used herein the term "substantially low" means a molar concentration less than 1.5 mole percent. DETAILED DESCRIPTION

[0029] The following detailed description is merely exemplary in nature and is not intended to limit the various embodiments or the application and uses thereof. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description. The Figures have been simplified by the deletion of a large number of apparatuses customarily employed in a process of this nature, such as vessel internals, temperature and pressure controls systems, flow control valves, recycle pumps, etc. which are not specifically required to illustrate the performance of the invention.

Furthermore, the illustration of the process of this invention in the embodiment of a specific drawing is not intended to limit the invention to specific embodiments set out herein.

[0030] As depicted, process flow lines in the figures can be referred to, interchangeably, as, e.g., lines, pipes, branches, distributors, streams, effluents, feeds, products, portions, catalysts, withdrawals, recycles, suctions, discharges, and caustics.

[0031] An embodiment of a process for maximizing production of heavy naphtha from a hydrocarbon stream is addressed with reference to a process and apparatus 100 according to an embodiment as shown in FIG.1. Referring to FIG.1, the process and apparatus 100 comprise a hydrotreating reactor 110, a hydrocracking reactor 120, a separator 130, a flash drum 140, a stripping column 150, a fractionation column 160, a scrubber column 170, and a recycle gas compressor 190. As shown in FIG. 1, a light cycle oil stream comprising mono- aromatics, di-aromatics and tri-aromatics in line 102 is provided to the hydrotreating reactor 110. The light cycle oil stream in line 102 may be combined with a first hydrogen stream in line 194 as described hereinafter in detail so that a combined stream is obtained in line 104. The combined stream in line 104 is passed to the hydrotreating reactor 110.

[0032] The hydrotreating reactor 110 can include one or more beds of hydrotreating catalyst to provide a hydrotreated effluent stream. Although not shown in FIG. 1, the combined stream in line 104 may be separated into a plurality of streams. Therefore, a stream from the plurality of streams may be sent to a top hydrotreating catalyst bed and remaining streams may be passed to the downstream hydrotreating catalyst beds in the hydrotreating reactor 110 as a quench stream for the effluent stream exiting the upstream hydrotreating catalyst bed. Each bed can comprise similar or different catalyst compared to the other beds of the hydrotreating reactor. The hydrotreating reactor 110, provides for the removal of sulfur and/or nitrogen from the combined stream 104 to provide a hydrotreated effluent stream in line 112.

[0033] Although not shown in FIG. 1, the light cycle oil stream in line 102 and the first hydrogen stream in line 194 may be separately passed in to the hydrotreating reactor 110. In hydrotreating reactor 110, the light cycle oil stream is subjected to hydrotreating in the presence of first hydrogen stream and a hydrotreating catalyst under suitable hydrotreating conditions to provide the hydrotreated effluent stream in line 112. In hydrotreating reactor 110, the hydrotreating conditions are so maintained to saturate the di-aromatics and the tri aromatics while minimizing the saturation of mono-aromatics present in the light cycle oil stream or combined stream to provide the hydrotreated effluent stream in line 112. Under the hydrotreating conditions to saturate the di-aromatics and the tri-aromatics while minimizing the saturation of mono-aromatics, the hydrotreated effluent stream in line 112 may comprise 30 to 80 wt-% or 40 to 70 wt-% mono-aromatics. Further, the amount of di-aromatics and tri aromatics present in the hydrotreated effluent stream in line 112 may not be more than 20 wt- %, or not more than 15 wt-%. The hydrotreating conditions may comprise a temperature of 290°C to 4lO°C, or of 290°C to 340°C. The hydrotreating pressure may comprise a pressure from 3000 kPa (435 psig) to 6000 kPa (870 psig).

[0034] Applicants have found that hydrotreating the LCO feed in the presence of hydrogen limited to saturate predominantly di-aromatics and tri-aromatics in the LCO to mono-aromatics, while minimizing saturation of mono-aromatics, provides a resulting effluent that is suitable for co-processing with a kerosene stream in a hydrocracking reactor and improves retention of naphtha and monoaromatics. Accordingly, a limited

stoichiometric quantity of hydrogen sufficient to saturate only the di-aromatics and tri aromatics, while excluding the mono-aromatic saturation, is advantageous in the

hydrotreating reactor to produce a more valuable product slate.

[0035] At least a portion of the hydrotreated effluent stream in line 112 is passed to a hydrocracking reactor 120. A second hydrogen stream in line 196 is also passed to the hydrocracking reactor 120. In accordance with an exemplary embodiment as shown in FIG.l, at least a portion of the hydrotreated effluent stream in line 112 may be mixed with a kerosene stream in line 106 to provide a mixed stream in line 114 and the mixed stream is passed to the hydrocracking reactor 120 operating at hydrocracking conditions to hydrocrack at least a portion of the hydrotreated effluent stream and the kerosene stream in the presence of the second hydrogen stream and a hydrocracking catalyst to provide a hydrocracked effluent stream in line 122. The kerosene stream in line 106 may be a straight run kerosene from an external source. Alternatively, the kerosene stream may comprise at least a portion of recycle kerosene fraction in line 163, described later. In an embodiment, the kerosene stream in line 106 may comprise both a portion of straight run kerosene and the recycled kerosene stream.

[0036] The hydrocracking reactor 120 may comprise one or more beds of hydrocracking catalyst to provide the hydrocracked effluent stream in line 122. In accordance with the process of the present disclosure, the mixed stream may comprise 5 wt-% to 95 wt-% of the at least portion of the hydrotreated effluent stream and 95 wt-% to 5 wt-% the kerosene stream. In an exemplary embodiment, the mixed stream comprises 20 wt-% to 40 wt-% of the at least portion of the hydrotreated effluent stream and 60 wt-% to 80 wt-% the kerosene stream.

[0037] As shown in FIG.l, the mixed stream in line 114 may be combined with the second hydrogen stream in line 196 to obtain a combined stream in line 116. The combined stream is then passed to the hydrocracking reactor 120 comprising one or more of a hydrocracking catalyst bed to provide a hydrocracked effluent stream in line 122.

Nevertheless, the hydrotreated effluent stream in line 112, the second hydrogen stream in line 196, and the kerosene stream in line 106 may be sent to the hydrocracking reactor 120 separately to provide the hydrocracked effluent stream in line 122. Each of the

hydrocracking catalyst beds can comprise similar or different catalyst compared to the other beds of the hydrocracking reactor 120. In the hydrocracking reactor 120, at least a portion of the hydrotreated effluent stream and the kerosene stream are hydrocracked at hydrocracking conditions in the presence of the second hydrogen stream and the hydrocracking catalyst to provide the hydrocracked effluent stream in line 122. The hydrocracking conditions of the hydrocracking reactor 120 comprise a hydrocracking pressure from 2758 kPa(g) (400 psig) to 10000 kPa(g) (1450 psig), or 2758 kPa(g) (400 psig) to 6000 kPa(g) (870 psig) and a hydrocracking temperature of 300°C to 400°C, or 320°C to 380°C.

[0038] The catalyst beds of the hydrocracking reactor 120 may comprise hydrocracking catalysts that utilize amorphous silica-alumina bases or low-level zeolite bases combined with one or more Group VIII or Group VIB metal hydrogenating components. The zeolite cracking bases are sometimes referred to in the art as molecular sieves and are usually composed of silica, alumina and one or more exchangeable cations such as sodium, magnesium, calcium, rare earth metals, etc. They are further characterized by crystal pores of relatively uniform diameter between 4 and 14 Angstroms. Zeolites having a relatively high silica/alumina mole ratio between 3 and 12 may be employed. Suitable zeolites found in nature include, for example, mordenite, stilbite, heulandite, ferrierite, dachiardite, chabazite, erionite and faujasite. Suitable synthetic zeolites include, for example, the B, X, Y and L crystal types, e.g., synthetic faujasite and mordenite. The preferred zeolites are those having crystal pore diameters between 8-12 Angstroms, wherein the silica/alumina mole ratio is 4 to 6. One example of a zeolite falling in the preferred group is synthetic Y molecular sieve.

[0039] The natural occurring zeolites are normally found in a sodium form, an alkaline earth metal form, or mixed forms. The synthetic zeolites are nearly always prepared first in the sodium form. In any case, for use as a cracking base it is preferred that most or all of the original zeolitic monovalent metals be ion-exchanged with a polyvalent metal and/or with an ammonium salt followed by heating to decompose the ammonium ions associated with the zeolite, leaving in their place hydrogen ions and/or exchange sites which have actually been decationized by further removal of water. Zeolites, such as Y zeolites may be steamed and acid washed to dealuminate the zeolite structure.

[0040] Mixed polyvalent metal-hydrogen zeolites may be prepared by ion-exchanging first with an ammonium salt, then partially back exchanging with a polyvalent metal salt and then calcining. In some cases, as in the case of synthetic mordenite, the hydrogen forms can be prepared by direct acid treatment of the alkali metal zeolites. In one aspect, the preferred cracking bases are those which are at least 10 percent, and preferably at least 20 percent, metal-cation-deficient, based on the initial ion-exchange capacity. In another aspect, a desirable and stable class of zeolites is one wherein at least 20 percent of the ion exchange capacity is satisfied by hydrogen ions.

[0041] The active metals employed in the preferred hydrocracking catalysts of the present invention as hydrogenation components are those of Group VIII, i.e., iron, cobalt, nickel, ruthenium, rhodium, palladium, osmium, iridium and platinum. In addition to these metals, other promoters may also be employed in conjunction therewith, including the metals of Group VIB, e.g., molybdenum and tungsten. The amount of hydrogenating metal in the catalyst can vary within wide ranges. Broadly speaking, any amount between 0.05 percent and 30 percent by weight may be used. In the case of the noble metals, it is normally preferred to use 0.05 to 2 wt-%.

[0042] The foregoing catalysts may be employed in undiluted form, or the powdered catalyst may be mixed and copelleted with other relatively less active catalysts, diluents or binders such as alumina, silica gel, silica-alumina cogels, activated clays and the like in proportions ranging between 5 and 90 wt-%. These diluents may be employed as such or they may contain a minor proportion of an added hydrogenating metal such as a Group VIB and/or Group VIII metal. Additional metal promoted hydrocracking catalysts may also be utilized in the process of the present invention which comprise, for example, aluminophosphate molecular sieves, crystalline chromosilicates and other crystalline silicates.

[0043] The hydrocracking catalyst preferably has high activity such as comprising at least 40 to 60 wt-% dealuminated Y zeolite or at least 15 to 35 wt-% non-dealuminated Y zeolite or at least 3 to 10 wt-% beta zeolite, or some combination thereof yielding similar activity. In each case, mass-transfer limitations are expected to be significant and thus smaller-diameter extrudates such as 1/16 inch cylinders or 1/16 inch trilobes may give the best performance. The hydrocracking catalyst beds of the hydrocracking reactor 120 may comprise 30 to 60% of the total catalyst volume in the hydrocracking reactor 120.

[0044] Referring back to FIG.1, at least a portion of the hydrocracked effluent stream in line 122 may be passed to the separator 130. Optionally, a water stream in line 124 may be mixed with hydrocracked effluent stream in line 122 prior to passing the hydrocracked effluent stream to the separator 130 for separation. In accordance with an embodiment, the separator 130 is a cold separator, and may be interchangeably referred to as the cold separator 130. The separator 130 separates the hydrocracked effluent stream to provide a vaporous stream comprising predominantly hydrogen and containing hydrogen sulfide in line 134 and a liquid stream in line 132. In an aspect, the separator 130 may be in direct communication with the hydrocracking reactor 120 via the hydrocracked effluent stream in line 122.

Accordingly, the hydrocracked effluent stream in line 122 may be passed directly to the separator 130. The separator 130 may be operated at l00°F (38°C) to l50°F (66°C), suitably 1 l5°F (46°C) to l45°F (63°C), and just below the pressure of the hydrocracking reactor 120.

[0045] The vaporous stream comprising predominantly hydrogen in line 134 may be passed to the scrubber column 170 to scrub, inter alia, to reduce the concentration of hydrogen sulfide to provide a scrubbed vaporous stream in line 172. The vaporous stream in line 134 may be passed through a trayed or packed scrubber column 170 where it is scrubbed by means of an absorbent liquid such as an aqueous solution fed by line 171 to remove acid gases including hydrogen sulfide and carbon dioxide by absorbing them into the aqueous solution. Preferred aqueous solutions include lean amines such as alkanolamines,

diethanolamine, monoethanolamine, and methyldiethanolamine. Other amines can be used in place of or in addition to the preferred amines. The lean amine contacts the cold vaporous stream and absorbs acid gas contaminants such as hydrogen sulfide and carbon dioxide. The resultant "sweetened" scrubbed vaporous stream is taken out from an overhead outlet of the scrubber column 170 in the scrubbed vaporous stream in line 172, and a rich amine is taken out from the bottoms at a bottom outlet of the scrubber column 170 in a recycle absorption bottoms line 173. The spent absorbent liquid from the bottoms may be regenerated and recycled back (not shown) to the scrubber column 170.

[0046] A make-up hydrogen stream in line 108 may be combined with the scrubbed vaporous stream comprising predominantly hydrogen in line 172 to obtain a combined hydrogen rich stream in line 174. A purge stream in line 176 may be withdrawn from the combined hydrogen rich stream in line 174 and the remaining portion of the combined hydrogen rich stream in line 178 may be passed to the recycle gas compressor 190. In an embodiment, the combined hydrogen rich stream, as a whole, may be passed to the recycle gas compressor 190 to compress the combined hydrogen rich stream. Thereafter, a portion of the compressed combined hydrogen rich stream in line 194 may be passed to the

hydrotreating reactor 110 as the first hydrogen stream and a remaining portion of the compressed combined hydrogen rich stream in line 196 may be passed to the hydrocracking reactor 120 as the second hydrogen stream. [0047] Referring back to the separator 130, at least a portion of the liquid stream in line

132 may be first passed to the fractionation column 160 to provide heavy naphtha stream. As shown in FIG.l, the liquid stream in line 132 may be let down in pressure and flashed in the flash drum 140 to further separate the liquid stream into a flash drum liquid stream in line 142 and a flash drum vaporous stream in line 144. In an embodiment, the flash drum may be a cold flash drum and may be interchangeably referred to as the cold flash drum 140. The flash drum liquid stream in line 142 is then subjected to fractionation to provide a heavy naphtha stream. In embodiments, there may be an additional separator operating at high temperature upstream of the separator 130. The additional separator may be a hot separator. Further, the additional separator may have a corresponding additional flash drum. The additional flash drum may be a hot flash drum.

[0048] At least a portion of the flash drum liquid stream in line 142 may be first passed to a stripper column 150 to strip light gases off from the flash drum liquid stream. Any suitable stripping media in line 143 can be used in the stripper column 150 to separate the light gases and to provide a stripped liquid stream in line 152. In an embodiment, the stripping media may be steam. The stripper column 150 may be operated with a bottoms temperature between 149° C. (300° F.) and 260° C. (500° F.) and an overhead pressure of 0.5 MPa (gauge) (73 psig) to 2.0 MPa (gauge) (290 psig). Thereafter, the stripped liquid stream in line 152 may be passed to a fractionation column 160 to fractionate the stripped liquid in to various fractions based on their boiling range including but not limited to a heavy naphtha fraction and an unconverted bottom stream. The fractionation column 160 may be interchangeably referred to as the first fractionation column. The fractionation column 160 is maintained at a pressure between 98 kPa(a) and 295 kPa(a) and at a temperature of 250° C to 400° C. In an

embodiment, the fractionation column 160 is an atmospheric column. In accordance with an exemplary embodiment as shown in FIG.l, the liquid stream in line 142 may be passed directly to the fractionation column 160 to provide an unconverted bottoms stream (UCO) withdrawn in line 162, a kerosene fraction in line 163 and a heavy naphtha fraction withdrawn in line 164.

[0049] Any of the above lines, conduits, units, devices, vessels, surrounding

environments, zones or similar may be equipped with one or more monitoring components including sensors, measurement devices, data capture devices or data transmission devices. Signals, process or status measurements, and data from monitoring components may be used to monitor conditions in, around, and on process equipment. Signals, measurements, and/or data generated or recorded by monitoring components may be collected, processed, and/or transmitted through one or more networks or connections that may be private or public, general or specific, direct or indirect, wired or wireless, encrypted or not encrypted, and/or combination(s) thereof; the specification is not intended to be limiting in this respect. Further, the figure shows one or more exemplary sensors such as 10, 11, 12, 13, 14, and 15 located on or more conduits. Nevertheless, there may be sensors present on every stream so that the corresponding parameter(s) can be controlled accordingly.

[0050] Signals, measurements, and/or data generated or recorded by monitoring components may be transmitted to one or more computing devices or systems. Computing devices or systems may include at least one processor and memory storing computer-readable instructions that, when executed by the at least one processor, cause the one or more computing devices to perform a process that may include one or more steps. For example, the one or more computing devices may be configured to receive, from one or more monitoring component, data related to at least one piece of equipment associated with the process. The one or more computing devices or systems may be configured to analyze the data. Based on analyzing the data, the one or more computing devices or systems may be configured to determine one or more recommended adjustments to one or more parameters of one or more processes described herein. The one or more computing devices or systems may be configured to transmit encrypted or unencrypted data that includes the one or more recommended adjustments to the one or more parameters of the one or more processes described herein.

[0051] Turning now to FIG. 2, another exemplary embodiment of the process and apparatus for maximizing production of heavy naphtha from a hydrocarbon stream is addressed with reference to a process and apparatus 200. Many of the elements in the FIG. 2 have the same configuration as in FIG. 1 and bear the same respective reference number and have similar operating conditions. Elements in FIG. 2 that correspond to elements in FIG. 1 but have a different configuration bear the same reference numeral as in FIG. 1 but are marked with a prime symbol (’). The apparatus and process in FIG. 2 are the same as in FIG.

1 with the exception of the noted following differences. In accordance with the exemplary embodiment as shown in the FIG. 2, the process and apparatus includes a second

fractionation column 210 in addition to the first fractionation column 160.

[0052] The stripped liquid stream in line 152 may be passed to a first fractionation column 160 to fractionate the stripped liquid stream in to various fractions based on their boiling range including but not limited to a heavy naphtha fraction and an unconverted bottom stream. As shown in FIG. 2, the heavy naphtha fraction is withdrawn in line 164 and the unconverted bottoms stream (UCO) is withdrawn in line 162. The unconverted bottom stream (UCO) typically comprises 190 °C plus material which collectively may be called as diesel however, with poor cetane from 30 to 40. Also, this unconverted bottom stream comprises significant amount of kerosene range material boiling in the range of from 190 °C to 290 °C.

[0053] Applicants have found that recycling the unconverted bottom stream back to the hydrocracking reactor 120 would lead to a loss in heavy naphtha selectivity due to increase in operating severity to crack the 290 °C plus material. Alternatively, the unconverted bottom stream (UCO) requires further upgradation prior to use as diesel owing to poor cetane of UCO. However, desired fractions can be recovered from the unconverted bottoms stream (UCO). Accordingly, the unconverted bottom stream (UCO) can be fractionated to provide a kerosene stream which may be recycled to produce more naphtha or may be use in other processes. Additionally, a diesel stream can be recovered from the unconverted bottom stream which, owing to prior removal of some of the aromatics, has an improved cetane of from 35 to 50.

[0054] Therefore, as shown in FIG.2, the unconverted bottom stream in line 162 may be sent to a second fractionation column 210 to maximize the yield of heavy naphtha. In the second fractionation column 210, the unconverted bottom stream in line 162 is separated in to a kerosene fraction and a diesel stream. The kerosene fraction is taken from the second fractionation column 210 overhead in line 214 and the diesel stream is withdrawn from the second fractionation column bottom in line 212. The kerosene fraction in line 214 may be recycled to the hydrocracking reactor 120 to maximize the selectivity/production of heavy naphtha. As shown in FIG. 2, the kerosene fraction in line 214 may be combined with the kerosene stream in line 106 so that a combined kerosene stream in line 106’ is obtained. The combined kerosene stream in line 106’ is then passed to the hydrocracking reactor 120. Although not shown in FIG. 2, the kerosene fraction in line 214 and the kerosene stream in line 106 may be sent to the hydrocracking reactor 120 separately to maximize the selectivity/production of heavy naphtha. In an embodiment, the kerosene stream to the hydrocracking reactor may comprise at least a portion of the kerosene fraction. In another embodiment, the kerosene stream to the hydrocracking reactor is the recycled kerosene fraction in line 214 from the second fractionation column 210. Nevertheless, the kerosene stream to the hydrocracking reactor may comprise straight run kerosene from an external source. Rest of the process in same as described in FIG.1.

SPECIFIC EMBODIMENTS

[0055] While the following is described in conjunction with specific embodiments, it will be understood that this description is intended to illustrate and not limit the scope of the preceding description and the appended claims. [0056] A first embodiment of the invention is a process for maximizing production of heavy naphtha from a hydrocarbon stream comprising providing a light cycle oil stream comprising mono-aromatics, di-aromatics and tri-aromatics to a hydrotreating reactor; hydrotreating the light cycle oil stream in the presence of a first hydrogen stream and a hydrotreating catalyst in the hydrotreating reactor operating at hydrotreating conditions to saturate the di-aromatics and the tri-aromatics while minimizing the saturation of mono aromatics and provide a hydrotreated effluent stream; hydrocracking at least a portion of the hydrotreated effluent stream and a kerosene stream in a hydrocracking reactor operating at hydrocracking conditions in the presence of a second hydrogen stream and a hydrocracking catalyst to provide a hydrocracked effluent stream; and fractionating at least a portion of the hydrocracked effluent stream to provide the heavy naphtha. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph, wherein the hydrotreating conditions comprise a temperature of 290°C to

340°C to provide the hydrotreated effluent comprising no more than 15 wt-% di-aromatics and tri-aromatics. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph, wherein the hydrotreating effluent stream comprises 30 to 80 wt-% mono-aromatics. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph further comprising mixing the at least portion of the hydrotreated effluent stream and the kerosene stream to provide a mixed stream and passing the mixed stream to the hydrocracking reactor. An embodiment of the invention is one, any or all of prior

embodiments in this paragraph up through the first embodiment in this paragraph, wherein the mixed stream comprises 20 wt-% to 40 wt-% of the at least portion of the hydrotreated effluent stream and 60 wt-% to 80 wt-% the kerosene stream. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph, wherein the hydrocracking conditions comprise a hydrocracking pressure from 2758 kPa(g) (400 psig) to 10000 kPa(g) (1450 psig) and a hydrocracking temperature of

300°C to 400°C. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph further comprising passing at least a portion of the hydrocracked effluent stream to a separator to provide a vaporous stream and a liquid stream and fractionating the liquid stream to provide the heavy naphtha.

An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph, wherein the step of fractionation comprises passing at least a portion of the hydrocracked effluent stream to a first fractionation column to provide the heavy naphtha and an unconverted bottoms stream; and passing the unconverted bottoms stream to a second fractionation column to provide a kerosene fraction and a diesel stream. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph further comprising recycling the kerosene fraction to the hydrocracking reactor to maximize heavy naphtha production, wherein the kerosene stream comprises at least a portion of the kerosene fraction. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph, wherein the kerosene stream comprises straight run kerosene from an external source. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the first embodiment in this paragraph, further comprising at least one of sensing at least one parameter of the process for

maximizing production of heavy naphtha and generating a signal or data from the sensing; generating and transmitting a signal; or generating and transmitting data. [0057] A second embodiment of the invention is a process for maximizing production of heavy naphtha from a hydrocarbon stream comprising providing a light cycle oil stream comprising mono-aromatics, di-aromatics and tri-aromatics to a hydrotreating reactor;

hydrotreating the light cycle oil stream in the presence of a first hydrogen stream and a hydrotreating catalyst in the hydrotreating reactor operating at hydrotreating conditions to saturate the di-aromatics and tri-aromatics while minimizing the saturation of mono aromatics and provide a hydrotreated effluent stream; hydrocracking at least a portion of the hydrotreated effluent stream and a kerosene stream in a hydrocracking reactor operating at hydrocracking conditions comprising a hydrocracking pressure from 2758 kPa(g) (400 psig) to 10000 kPa(g) (1450 psig) and a hydrocracking temperature of 300°C to 400°C, in the presence of a second hydrogen stream and a hydrocracking catalyst to provide a

hydrocracked effluent stream; and fractionating at least a portion of the hydrocracked effluent stream to provide the heavy naphtha. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph, wherein the hydrotreating conditions comprise a temperature of 290°C to 340°C to provide the hydrotreated effluent stream comprising no more than 15 wt-% di-aromatics and tri aromatics. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph, wherein the step of fractionation comprises passing a portion of the hydrocracked effluent stream to a first fractionation column to provide the heavy naphtha and an unconverted bottoms stream; and passing the unconverted bottoms stream to a second fractionation column to provide a kerosene fraction and diesel stream. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph further comprising recycling the kerosene fraction to the hydrocracking reactor to maximize heavy naphtha production, wherein the kerosene stream comprises at least a portion of the kerosene fraction. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the second embodiment in this paragraph, wherein the kerosene stream comprises straight run kerosene from an external source.

[0058] A third embodiment of the invention is a process for maximizing production of heavy naphtha from a hydrocarbon stream comprising providing a light cycle oil stream comprising mono-aromatics, di-aromatics and tri-aromatics to a hydrotreating reactor;

hydrotreating the light cycle oil stream in the presence of a first hydrogen stream and a hydrotreating catalyst in the hydrotreating reactor operating at hydrotreating conditions to saturate the di-aromatics and tri-aromatics while minimizing the saturation of mono aromatics and provide a hydrotreated effluent stream; hydrocracking at least a portion of the hydrotreated effluent stream and a kerosene stream in a hydrocracking reactor operating at hydrotreating conditions in the presence of a second hydrogen stream and a hydrocracking catalyst to provide a hydrocracked effluent stream; and passing the hydrocracked effluent stream to a first fractionation column to provide the heavy naphtha and an unconverted bottoms stream; and passing the unconverted bottoms stream to a second fractionation column to provide a kerosene fraction and diesel stream; and recycling the kerosene fraction to the hydrocracking reactor, wherein the kerosene stream comprises at least a portion of the kerosene fraction. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the third embodiment in this paragraph, wherein the kerosene stream comprises straight run kerosene from an external source. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the third embodiment in this paragraph, wherein the hydrotreating conditions comprise a temperature of 290°C to 340°C to provide the hydrotreated effluent comprising no more than 15 wt-% di aromatics and tri-aromatics. An embodiment of the invention is one, any or all of prior embodiments in this paragraph up through the third embodiment in this paragraph, wherein the hydrocracking conditions comprise a hydrocracking pressure from 2758 kPa(g) (400 psig) to 10000 kPa(g) (1450 psig) and a hydrocracking temperature of 300°C to 400°C.

[0059] Without further elaboration, it is believed that using the preceding description that one skilled in the art can utilize the present invention to its fullest extent and easily ascertain the essential characteristics of this invention, without departing from the spirit and scope thereof, to make various changes and modifications of the invention and to adapt it to various usages and conditions. The preceding preferred specific embodiments are, therefore, to be construed as merely illustrative, and not limiting the remainder of the disclosure in any way whatsoever, and that it is intended to cover various modifications and equivalent arrangements included within the scope of the appended claims. [0060] In the foregoing, all temperatures are set forth in degrees Celsius and, all parts and percentages are by weight, unless otherwise indicated.