KR20080066068A - Processing of fcc naphtha - Google Patents

Abstract

A fluid cracked naphtha stream is subjected to hydrodesulfurization and fractionation, preferably simultaneously in catalytic distillation reactors. The overheads and a portion of the bottoms from the fractionation are recombined to produce a naphtha blend having an ASTM D-8695% point greater than the end point of the overheads and less than the ASTM D-86 95% point of the bottoms.

Description

Processing of FCC naphtha {PROCESSING OF FCC NAPHTHA}

The present invention relates to a process for desulfurization of fluid catalytic cracked naphtha in the entire boiling region. More specifically, the present invention utilizes a catalytic distillation step that reduces sulfur to very low levels in the naphtha stream of the entire boiling region, makes hydrogen more useful, and results in less olefin hydrogenation. More specifically, the present invention relates to a method for adjusting the end point of blended gasoline from treated naphtha by desulfurizing and simultaneously distilling naphtha and then recombining the fractions for the desired end point.

<Related Information>

Petroleum distillate streams contain various organic chemical components. In general, the flow is characterized by its boiling region, which determines its composition. Processing of the flow also affects the composition. For example, products from either catalytic cracking or thermal cracking processes contain high concentrations of olefinic materials as well as saturated (alkane) materials and polyunsaturated materials (diolefins). In addition, these components may be any of various isomers of the compound.

The composition of raw naphtha or straight run naphtha as received from a crude oil distiller is primarily influenced by the crude oil source. Naphtha from paraffinic crude oil sources have more saturated straight or cyclic compounds. In general, most “sweet” (low sulfur) crude oils and naphtha are paraffinic. Naphthenic crude oil contains more unsaturateds and cyclic and polycyclic compounds. Crude oils of higher sulfur content tend to be naphthenic. The treatment of different direct current naphthas may vary slightly depending on their composition due to the crude oil source.

Modified naphtha or reformers generally do not require any further treatment except distillation or solvent extraction for the separation of approximately valuable aromatic products. The modified naphtha is essentially free of sulfur contaminants because of its pretreatment for processing and the intensity of the processing itself.

The cracked naphtha as obtained from the catalytic cracker has a relatively high octane number as a result of the olefinic and aromatic compounds contained therein. In some cases, these fractions can comprise as much as half of gasoline in refinery reservoirs and can represent a very large portion of the octane number.

Catalytically decomposed naphtha (a gasoline boiling zone material) currently forms a very large portion (≒ 1/3) of gasoline product reservoirs in the United States and provides most of the sulfur. Sulfur impurities may need to be removed, usually by hydrotreating, to meet product specifications or to comply with environmental regulations. Some users require that the sulfur of the final product be less than 50 wppm.

The most common method of sulfur compound removal is by hydrodesulfurization (HDS), which passes petroleum distillate onto a solid particulate catalyst comprising a metal hydride supported on an alumina support. In addition, a large amount of hydrogen is included in the feed. The following scheme illustrates the reaction in a typical HDS unit:

(1) RSH + H _2- → RH + H ₂ S

(2) RCl + H _2- → RH + HCl

(3) 2RN + 4H _2- → 2RH + 2NH ₃

(4) ROOH + 2H _2- → RH + 2H ₂ O

The operating conditions of a typical HDS reaction are as follows:

Temperature, ℉ 600-780

Pressure, psig 600-3000

H ₂ recycling rate, SCF / bbl 1500-3000

New H ₂ configuration, SCF / bbl 700-1000

After the hydrogenation is complete, the product can be fractionated or simply flash off to release hydrogen sulfide and collect desulphurized naphtha. As the octane number of naphtha decreases and the olefin reservoir for other uses decreases, the loss of olefins by secondary hydrogenation is not good.

In addition to providing high octane blending components, cracked naphtha is often used as an olefin source in other processes such as etherification, oligomerization and alkylation. The conditions of naphtha fraction hydrotreatment to remove sulfur also saturate some olefinic compounds in the fraction, resulting in a reduction in octane number and loss of source olefins.

Various proposals have been made to remove sulfur while maintaining more desirable olefins. The olefins in the cracked naphtha are mainly present in the low boiling fraction of the naphtha, and the sulfur-containing impurities tend to concentrate in the high boiling fraction, so the most common solution was prefractionation prior to hydrotreatment. Pre-fractionation produces hard boiling area naphtha boiling in the C ₅ region up to about 250 ° F. and heavy boiling area naphtha boiling in the range of about 250-475 ° F.

The main hard or low boiling sulfur compounds are mercaptans, while the heavy or high boiling compounds are thiophenes and other heterocyclic compounds. Separation by fractionation alone does not remove mercaptans. However, to date, mercaptans have been removed by an oxidative process involving caustic washing. The combination of fractional and heavy fraction hydrotreatment following oxidative removal of mercaptans is described in U.S. Pat. Patent 5,320,742 is disclosed. In oxidative removal of mercaptans, mercaptans are converted to the corresponding disulfides.

Some U.S. The patent discloses simultaneous distillation and desulfurization of naphtha, including 5,597,476; 5,779,883; 6,083,378; 6,303,020; 6,416,658; 6,444,118; 6,495,030; 6,678,830 and 6,824,679. In each of these patents naphtha is separated into two to three fractions based on the boiling point. In general, combining fractions is only mentioned in the past. In commercial designs, however, it is practical to combine all treated naphtha fractions and send the whole to gasoline blending.

In a commercial design that simply reblends all HCNs and MCNs at their production rate, the end point of the resulting FCC gasoline is essentially the same as the end point of the feed.

It is an advantage of the present invention to separate the naphtha stream of the entire boiling region by separating it into boiling region fractions and subjecting the fractions simultaneously to hydrodesulfurization and fractionation. It is a further advantage of the present invention that sulfur can be removed from the light portion of the stream to the heavy portion of the stream without any substantial olefin loss. While the hydrogenation of olefins is reduced, it is understood that substantially all of the sulfur contained in naphtha is ultimately converted to H ₂ S, which is quickly removed from the catalyst zone and easily distilled off from hydrocarbons to minimize the production of recombinant mercaptans. It is a concrete feature. Finally, another specific feature of the present invention is that the fractions are optionally combined so that the endpoint (ASTM D-86 95% point) can be adjusted as desired for various situations.

<Overview of invention>

In short, the present invention relates to a method for forming a H ₂ S by contacting naphtha with hydrogen in the presence of a hydrodesulfurization catalyst to react with the hydrogen a portion of the organic sulfur compound contained in the naphtha, and distilling the naphtha stream by distillation. Separating into heavy fractions; Recovering the light fractions from the column top; Recovering the heavy fractions from the bottom; And a portion of the heavy fraction in combination with the hard fraction, ASTM D-86 95, which is higher than the end point of the hard fraction and lower than the ASTM D-86 95% point of the heavy fraction, preferably lower than the D-86 95% point of the feed naphtha. A method for desulfurization of catalytic cracking naphtha comprising obtaining a% point.

In one embodiment, the whole boiling region naphtha containing organic sulfur compounds, including diolefins and mercaptans, is separated into a first heavy fraction and a hard fraction. The light fraction is contacted with a thioetherification catalyst under conditions of simultaneous fractionation and reaction, thereby reacting the diolefin with mercaptan to form an organic sulfide and fractionating the organic sulfide into a first heavy fraction. The light fraction with reduced sulfur content is recovered from the column top.

The first heavy fraction is used as a feed to be recovered and fractionated into the middle fraction and the second heavy fraction. Both fractions are individually contacted with a hydrodesulfurization catalyst and hydrogen under conditions of simultaneous fractionation and reaction, thereby reacting organic sulfur, including organic sulfides from the light fraction, with hydrogen to form H ₂ S and hydrocarbons. The intermediate fraction with reduced sulfur content relative to the first heavy feed is recovered and combined with the light fraction. The second heavy fraction with reduced sulfur content relative to the first heavy feed is recovered so that a portion comprising less than all of the second heavy fraction is combined with the hard and intermediate fractions to create the selected endpoint. The portion of the second heavy fraction with reduced sulfur content relative to that of the first heavy feed is higher than the endpoint of the middle and light fraction combination and less than the ASTM D-86 95% point of the second heavy fraction. Combined with the combination of middle and light fractions to yield. Unused heavy fractions are sent to diesel fuel processing.

The present invention can be varied by adjusting the amount of heavy cracked naphtha blended into hard / medium cracked naphtha, thereby providing a new configuration that gives the refiner control over the end point of gasoline produced. All excess heavy cracked naphtha produced is suitable for the route to the distillate hydrotreater or directly to the diesel reservoir. This also gives some flexibility in changing the amount of gasoline and diesel fuel produced in refineries. Because less than all of the recovered heavy naphtha fraction is blended with the intermediate fraction, up to 100% desulfurized heavy fraction is expected to be used.

1 is a simplified flow chart in an embodiment of the present invention in schematic form.

2 is a simplified flowchart in schematic form of a second embodiment of the present invention.

FIG. 3 is a simplified flow diagram in a schematic form of an embodiment of the present invention using one stationary phase pass-through HDS highly purified reactor in combination with a distillation column.

4 is a simplified flow diagram in schematic form of an embodiment of the invention using a fixed bed series pass HDS reactor.

The process for simultaneously desulfurizing and distilling the fluid cracking naphtha in the entire boiling region was described. See, for example, US Pat. No. 5,597,476, which is hereby incorporated by reference in its entirety. This patent discloses a two-stage process in which naphtha is fed to a first distillation column reactor acting as a depentanizer or dehexanizer, wherein the light containing most of the olefins and mercaptans is present. The material boils into the first distillation reaction zone, where the mercaptan reacts with the diolefin to form sulfides, which are removed together with all the high boiling sulfur compounds at the bottom. The bottom is subjected to hydrodesulfurization in a second distillation column reactor, where the sulfur compound is converted to H ₂ S and removed. The second distillation column reactor desulfurizes FCC gasoline in a distillation environment. In the case of the present invention, the top and bottom flows are generated. The top product contains a middle zone cat-degraded naphtha (MCN) and usually covers a boiling region of 150-350 ° F., although there is some flexibility in the exact temperature. The bottom product contains heavy cat-digested naphtha (HCN) and has a common endpoint near 480 ° F.

To date MCN and HCN have simply been recombined and fed to conventional product strippers to remove dissolved gases such as H ₂ S and H ₂ . In the present invention, it has been found that it is useful in some situations to reduce the amount of HCN blended back to MCN and thus reduce the end point of the gasoline product. Adjusting the amount of HCN blended into MCN gives the refiner a means to control the end point of the product within the range of 350-450 ° F. This is a powerful means of potentially regulating the quality of gasoline seasonally and quickly meeting product specifications for the boutique market.

According to the invention, the hydrodesulfurization reaction and distillation separation can be carried out simultaneously in the reaction distillation zone, or in the distillation zone following the series pass reaction zone in the fixed bed, or in a combination of these two modalities.

In the process of the invention, the entire boiling region naphtha stream containing the organic sulfur compound and diolefin boils a portion of the stream containing the low boiling organic sulfur compound and diolefin, which are generally mercaptans, so that the Group VIII metal under sulfide forming conditions By contact with the hydrogenation catalyst, it can be fractionated in the first distillation column reactor. The low boiling portion of the stream with reduced amounts of organosulfur compounds and diolefins is recovered as hard naphtha columnar. Sulfides formed by the reaction of mercaptans with diolefins are removed from the column in a heavy column bottom with high boiling. The heavy bottoms contain a portion of the flow that has not been removed as tower tops. Although hydrogen is present in this column, it is present in an amount that keeps the catalyst in hydride form for the sulfide reaction, so that only a very small amount of olefins present are hydrogenated. In addition, the presence of diolefins in this fraction inhibits hydrogenation of the olefins, since the diolefins preferentially hydrogenate.

The heavy bottoms and hydrogen can be fed to a second distillation column reactor where the heavy bottoms are fractionated into middle naphtha fractions and heavy naphtha fractions. The organic sulfur compound in the middle naphtha portion is brought into contact with hydrogen at the top of the distillation column reactor in the presence of a hydrodesulfurization catalyst under conditions which convert the organic sulfur compound into H ₂ S which is removed together with the middle naphtha fraction in the tower. The high boiling organic sulfur compounds originally present in the stream and the sulfides produced in the first column are distillation columns in the presence of a hydrodesulfurization catalyst under conditions which convert the heavy sulfur compounds into H ₂ S, which is also removed together with intermediate naphtha in the column. It is in contact with hydrogen at the bottom of the reactor. H ₂ S is separated from the intermediate fraction and recovered after condensation. Heavy naphtha with reduced sulfur content is recovered as a bottoms. The recovered heavy, medium and hard naphtha fractions are then selectively blended to obtain an endpoint (ASTM D-86 95% point) that is lower than the heavy fraction and higher than the combination of hard and intermediate fractions.

The endpoint to be adjusted is measured by the ASTM D-86 method, which is standard in the refining industry. ASTM D-86 does not measure the actual boiling point due to the equipment used, but is still used as a standard. Because ASTM D-86 does not measure the actual boiling point, the endpoint according to the present method can be manipulated by blending high boiling raw materials with low boiling raw materials.

<Thioetherification and selective hydrogenation catalyst>

Catalysts useful for the mercaptan-diolefin reaction and selective hydrogenation of dienes include Group VIII metals. Generally, the metal is deposited as an oxide on the alumina support.

A preferred catalyst for the thioetherification reaction of the CD form is 54 wt% Ni on 8 to 14 mesh Al ₂ O ₃ (alumina) spheres, supplied by Calcicat as E-475-SR. Typical physical and chemical properties of the catalyst provided by the manufacturer are as follows:

table

E-475-SR

Shape sphere

Nominal size 8 × 14 mesh

Ni wt% 54

Support alumina

Hydrogen must be supplied to the reactor at a rate sufficient to maintain the reaction but below that which would cause the column to overflow, which is to be understood when the term "effective amount of hydrogen" is used herein. do. In general, the molar ratio of hydrogen to diolefin and acetylene in the feed is at least 1.0 to 1.0, preferably 2.0 to 1.0.

Thioetherification catalysts also promote the selective hydrogenation of polyolefins, such as diolefins contained in hard cracking naphtha, and, to a lesser extent, the isomerization of some single-olefins. When using a preferred Ni catalyst, the relative reaction rates for the various compounds range from faster to slower:

(1) Reaction of Diolefin with Mercaptan

(2) Hydrogenation of Diolefin

(3) Isomerization of Single-olefins

(4) hydrogenation of single-olefins.

An important reaction is the reaction of mercaptans with diolefins. In the presence of a catalyst the mercaptan will also react with the single-olefin. However, excess diolefins are present in the hard cracked naphtha feed relative to mercaptans, so the mercaptans preferentially react with them before reacting with the single-olefins. An important scheme describing the reaction is as follows:

Here, R ₁ or R ₂ may be either an alkyl group or a hydrogen atom.

This can be compared with the reaction which consumes the following hydrogen. The hydrogen used for the removal of mercaptans in thioetherification is only necessary to keep the catalyst in a reduced "hydride" state. In the simultaneous hydrogenation of dienes, hydrogen is consumed.

Selective Hydrogenation Catalyst

The catalysts can be used as individual Group VIII metal components or as mixtures with one another or with industry known modifiers, in particular those of Groups VIB and IB, for example hydrogenation of the type characterized by platinum, palladium, rhodium or mixtures thereof. It is a catalyst. Generally, the metal is deposited on the alumina support as an oxide. The support is usually a small diameter extrudate or sphere, usually alumina. Preferred catalysts for the selective hydrogenation of diolefins are alumina supported palladium catalysts.

<Catalyst structure>

The catalyst is typically in the form of an extrudate having a diameter of 1/8, 1/16 or 1/32 inch and an L / D of 1.5 to 10. The catalyst may also be in the form of spheres having the same diameter. In the general form it is present in very dense amounts and is preferably produced in the form of a catalytic distillation structure. The catalytic distillation structure must be able to function as a catalyst and as a mass transfer medium.

If a catalyst is used in the distillation column reactor, it is preferably produced in the form of a catalytic distillation structure. The catalytic distillation structure must be able to function as a catalyst and as a mass transfer medium. The catalyst preferably acts as a catalytic distillation structure by being supported and positioned in the column. Various catalyst structures for this use are described in U.S. Pat. Patent 4,443,559; 4,536,373; 5,057,468; 5,130,102; 5,133,942; 5,189,001; 5,262,012; 5,266,546; 5,348,710; 5,431,890; And 5,730,843.

Preferred structures are described in U.S. Pat. It is shown in patent 5,730,843. As disclosed therein, the structure is a rigid frame made of two substantially vertical double gratings spaced from each other and held firmly by a plurality of substantially horizontal rigidity members, and a plurality of tubes mounted on the grating. And a plurality of substantially horizontal wire mesh tubes forming a flow passage of the. At least a portion of the Joule's eye tube contains particulate catalyst material. The catalyst in the tube provides a reaction zone in which the catalytic reaction can take place and the joule provides a mass transfer surface for performing fractional distillation. Spacer elements provide changes in the density and loading of the catalyst and structural integrity, and provide sufficient vapor and liquid processing capacity.

In order to describe the embodiments of the present invention consistently, the same reference numerals are assigned to components having the same relations and general functions in the various drawings.

A first embodiment of the invention is now shown with reference to FIG. 1. Light FC naphtha is fed through a flow path 101 to a thioether distillation column reactor 10 comprising a phase 12 of a thioetherification catalyst. Hydrogen is supplied in an amount sufficient to keep the catalyst in the hydride state. In reactor 10, mercaptans in naphtha react with diolefins to form high boiling sulfides and are removed along with bottoms through flow path 103. The light naphtha product is taken off as a tops via the flow path 102 and sent to the final blend.

The bottoms of the flow path 103 are combined with a heavy FC naphtha stream from the flow path 104 to comprise a hydrodesulfurization distillation column reactor 20 comprising two phases 22 and 24 of two hydrodesulfurization catalysts through the flow path 105. Is supplied. This unit is also supplied with hydrogen. This may be co-fed to the bottom of the phase 24 as shown, or as a separate feed. In distillation column reactor 20, organic sulfur compounds, including sulfides produced in reactor 10, react with hydrogen to form hydrogen sulfide. The middle boiling region naphtha (MCN) is taken out as a tower top through the flow path 106, and hydrogen sulfide is stripped from the stripping apparatus 30 from which hydrogen sulfide is removed as a tower top through the flow path 107. The product MCN is withdrawn from the stripping device 30 as the bottoms through the flow path 108. The heavy naphtha stream HCN is withdrawn from the reactor 20 through the flow path 109 from the reactor 20 and the hydrogen sulfide is stripped from the stripper 40 through which the hydrogen sulfide is taken out as the tower top via the flow path 110. The product HCN is removed from the stripper as bottoms through the flow path 111. Once removed, the HCN is adapted to be sent to the diesel reservoir via the flow path 112 or to a distillate hydrotreater or other type of unit if further processing is needed. Some HCN is also conveyed to the MCN product through flow passage 113. The amount of HCN blended into MCN depends on the endpoint required for the final product. Higher endpoint temperatures will require more HCN and lower endpoints will require less HCN. The flow of MCN and preferred HCN combination is sent through the flow path 114 to the final blend.

In situations where heavy and light feed streams are provided separately, it is possible for the refiner to send some heavy feed directly to a diesel reservoir or other processing unit without treatment in the distillation column reactor 20. To enable this option, recycling of the HCN product back to the feed of the hydrodesulfurization distillation column reactor is introduced. In Figures 1 and 2 this connection is shown by dashed lines 109A and 111A. Only small amounts of heavy feed configuration are required to continue operation of the distillation column reactor 20. In addition, a small amount of HCN product flow is sent to a diesel or gasoline reservoir depending on which is required.

If the refiner determines that further processing is required for the HCN before it is sent to the diesel reservoir, the opportunity to save costs may arise by removing the stripper 40. Such a design is shown in FIG. 2. The desired ratio of HCN determined in consideration of the end point is transferred to the stripper 30 through the flow path 115, where it is mixed with the MCN to strip off the dissolved gas. The remaining HCN is sent directly to the distillation hydrotreater. Dissolved hydrogen and hydrogen sulfide in HCN do not pose a problem in a common distillation hydrotreater. This process design must be carefully considered, as dissolved gases can be a problem if the material needs to be stored prior to further processing.

In some cases, for example if the sulfur specification is extremely low, or if the mercaptan specification is very strict, further processing of the MCN / HCN blend may be necessary. This may take the form of various options such as adsorption phase, corrosive treatment unit (with or without extraction), mercaptan sweetening unit, second hydrotreating unit, and the like. These units are well known in the art and are not described.

Although the present invention has generally been described by the preferred embodiment in which a catalytic distillation reactor is used for hydrodesulfurization, any or all hydrodesulfurization may be carried out in a fixed bed single pass reactor as shown in FIGS. 3 and 4. have.

Further reduction in total sulfur can be achieved by transferring heavy naphtha flow (HCN) in column bottom 109 through flow path 115 from reactor 20 to stripper 30, where the feed is mixed with MCN. After the dissolved gas is stripped off, the entire product from the reactor 20 is sent to the highly polished reactor 50 via the flow path 108, where the conveying material is transferred to the hydrogen added through the flow path 108A. Is applied to further hydrodesulfurization in the fixed catalyst bed (52), and the product is sent to the separator (60) through the flow path (118), where H ₂ S and H ₂ are passed through the flow path (116). The purified product is separated off and the LCN is sent through the sidedraw flow path 114 to the final blend. By adjusting the operating conditions of separator 60, some or all HCN may be transferred to diesel in the final blend or through flow path 120. The unconverted sulfur is either extended recycled in the heavy recycling circuits 109A, 105 or easily converted in a diesel hydrotreater (not shown).

Although the present invention has generally been described by the preferred embodiment of using a catalytic distillation reactor for hydrodesulfurization, any or all hydrodesulfurization can be carried out in a fixed bed series pass reactor such as shown in FIGS. 3 and 4. have.

FIG. 4 shows the process of the present invention in which each hydrodesulfurization is carried out in a stationary pass-through reactor 310, 340 with appropriate control. Nevertheless, the product flow 102, 114 to the final blend and diesel is substantially the same as that produced by catalytic distillation HDS.

The feed 101 is hydrodesulfurized in the stationary pass-through reactor 310 and the product is passed through the flow path 312 to the stripper 320 where H ₂ S is removed. The liquid from stripper 320 with reduced sulfur content is sent to separator 330 via flow path 314 where LCN column top 102 is recovered and sent to the final blend.

The bottoms 103 are sent to a fixed bed series pass reactor 340 where it is contacted with a hydrodesulfurization catalyst 24. The bottoms are transferred to the stripping unit 30 to remove H ₂ S through the flow path 107. The sulfur content-reduced liquid bottoms are sent to the separator 350 via the flow path 318 and the MCH is withdrawn from the tower top 108 to the final blend via the flow path 114, while the top bottom 111 is Treated as one.

Pilot plant tests were conducted to demonstrate low end gasoline production from a wide range of boiling zone feedstocks. C ₅ water and most C ₆ water were recovered from the top of the thioetherized distillation column reactor where the entire zone of fluid catalytic cracking naphtha was treated to remove mercaptan from the distillation product. The bottoms from this thioetherification reactor had the properties shown in Table I below.

                               Table I

               Total sulfur (wppm) 1356

               Total RSH (wppm) n / a

               Total N (wppm) 65.5

               Bromine Number (g / 100g) 51.7

               Density (g / cc) 0.798

               ASTM D3710 Distillation Fahrenheit

               IBP 150

               5% 187

               10% 202

               20% 218

               30% 244

               40% 263

               50% 290

               60% 308

               70% 345

               80% 377

               90% 416

               95% 454

               EP 497

The hydrodesulfurization distillation column reactor was installed in a 3 "diameter column x 50 ft in length. The Co / Mo catalyst (DC-130 from Criterion Catalyst Company) was constructed in the same manner as described in US Pat. No. 5,730,843. The column was loaded and the operating conditions and results are shown in Table II below.

                               Table II

             Feed rate, lbs / hour 60.1

             Feed sulfur (wppm) 1356

             Reboiler hydrogen (scfh) 59.9

             Feed Pt. Hydrogen (scfh) 20.1

             Pressure (pig) 265

Throughput (bpd / ft ³ catalyst charge) 2.8

             Upper phase temperature ℉ 487

             Lower phase temperature ℉ 537

             Reflow Rate 2.45

             OH sulfur in feed (wppm) 593.9

             OH Br. # 71.3 in the feed

             OH product Sulfur (wppm) 46.7

             OH product RSH (wppm) 31.0

             OH Br # 42.9

             OH sulfur conversion (%) 92.1

             OH Br # conversion (%) 39.8

             Top product sulfur (wppm) 277.0

             Top bottom RSH (wppm) 2.7

             Combined OH & Btms Sulfur (wppm) 156.1

             Combined OH & Btms RSH 17.8

             Combined OH & Btms Br # 28.3

             OH recovery from feed% 56.9

             ASTM D-86 ℉

             IBP 184.8

             5% 195.1

             50% 218.3

             95% 268.2

             EP 291.1

             Investigation of the OH product Octane number 85.0

             Car octane number 77.3 in OH product

Some of the tops and the bottoms were blended and D-86 distillation was performed in the blend. Table III below shows the D-86 distillation data for various blends.

TABLE III

Claims (16)

H ₂ S is formed by contacting catalytic cracking naphtha with hydrogen in the presence of a hydrodesulfurization catalyst to react a portion of the organic sulfur compound contained in naphtha with hydrogen; Separating the naphtha stream into a light fraction and a heavy fraction by distillation; The light fractions were recovered as tops; Recover the heavy fraction as a bottoms; A method for desulfurization of catalytic cracking naphtha comprising combining a portion of the heavy fraction with the light fraction to obtain an ASTM D-86 95% point higher than the end point of the light fraction and lower than the ASTM D-86 95% point of the heavy fraction. The process of claim 1 wherein said contacting and separating are performed simultaneously in a reactive distillation zone. 3. The method of claim 2, wherein the heavy fraction is contacted with hydrogen in the presence of a hydrodesulfurization catalyst to react an organic sulfur compound portion contained therein with hydrogen to form H ₂ S; Separating the heavy fraction into a second light fraction and a second heavy fraction by distillation; Recovering the second light fraction as a column; Recovering the second heavy fraction as a bottoms. 4. The process of claim 3 wherein the contacting and separating of the heavy fractions is performed simultaneously in the reaction distillation zone. The process of claim 1 wherein said contacting and separating is carried out continuously in a series pass reaction zone of the stationary phase followed by a distillation zone. The method of claim 5, wherein the heavy fraction is contacted with hydrogen in the presence of a hydrodesulfurization catalyst to react an organic sulfur compound portion contained therein with hydrogen to form H ₂ S; Separating the heavy fraction into a second light fraction and a second heavy fraction by distillation; Recovering the second light fraction as a column; Recovering the second heavy fraction as a bottoms. 4. The process according to claim 3, wherein the contacting and separating of the heavy fractions is carried out continuously in a series pass reaction zone of the fixed bed followed by a distillation zone. The method of claim 1, (a) feeding a hydrogen and organic sulfur compound containing naphtha stream to a distillation column reactor comprising a phase of a hydrodesulfurization catalyst; (b) in the distillation column reactor, simultaneously (i) contacting naphtha with hydrogen in the presence of a hydrodesulfurization catalyst to react a portion of the organosulfur compound contained in naphtha with hydrogen to form H ₂ S; (ii) separating the naphtha stream into a light fraction and a heavy fraction; (c) recovering the light fraction from the distillation column reactor as a column; (d) recovering the heavy fraction from the distillation column reactor as a bottoms; And (e) combining a portion of the heavy fraction with the hard fraction to obtain an ASTM D-86 95% point that is higher than the endpoint of the light fraction and lower than the ASTM D-86 95% point of the heavy fraction. 9. The method of claim 8, wherein hydrogen sulfide is stripped off before the light fraction is combined with a portion of the heavy fraction. 10. The method of claim 9, wherein the heavy fraction is dehydrogenated before a portion of the heavy fraction is combined with the light fraction. The method of claim 8, wherein the blend is stripped of hydrogen sulfide. 9. The process of claim 8 wherein the naphtha stream is a fluid cracked naphtha of the entire boiling region containing olefins, mercaptans and other organic sulfur compounds, and the fluidized naphtha of the entire boiling region is treated prior to feeding to the distillation column reactor. To remove mercaptans and C ₆ and harder materials. 13. The process of claim 12 wherein the treatment is by thioetherization in a distillation column reactor comprising a thioetherification catalyst. (a) feeding a full boiling zone fluidized naphtha containing hydrogen and olefins, diolefins, mercaptans and other organic sulfur compounds to a first distillation column reactor comprising a thioetherification catalyst; (b) in the first distillation column reactor, simultaneously (i) reacting the diolefin with mercaptans to form sulfides, (ii) separating the C ₆ and lighter materials from the C ₇ and heavier materials comprising the sulfides by fractional distillation; (c) removing C ₆ and lighter material from the first distillation column reactor as a first tower column; (d) removing the C ₇ and heavier material from the first distillation column as a first column bottoms; (e) feeding hydrogen and the first column bottom to a second distillation column reactor comprising a phase of a hydrodesulfurization catalyst; (f) in the distillation column reactor, simultaneously (i) forming hydrogen sulfide by contacting hydrogen with a C ₇ and heavier material in the presence of a hydrodesulfurization catalyst to react sulfides and other organic sulfur compound moieties with hydrogen, (ii) separating the C ₇ and heavier material into a first fraction having an lower ASTM D-86 endpoint than the second fraction; (g) recovering the first fraction from the distillation column reactor as a second column; (h) recovering the second fraction from the distillation column reactor as a second bottoms; (i) removing the hydrogen sulfide by removing the second column still; (j) removing the hydrogen sulfide by removing the second column bottoms; And (k) combining a portion of the second fraction with the first fraction to obtain an ASTM D-86 95% point that is higher than the endpoint of the first fraction and lower than the ASTM D-86 95% point of the second fraction Method of treating the whole boiling region flow cracking naphtha comprising a. Fractionating naphtha of the entire boiling region containing organic sulfur compounds, including diolefins and mercaptans, into a first heavy fraction and a hard fraction; Contacting the light fraction with a thioetherification catalyst under conditions of simultaneous fractionation and reaction to react the diolefin with mercaptan to form an organic sulfide, and fractionate the organic sulfide into a first heavy fraction; Recovering the light fraction with reduced sulfur content as tower column; Recovering the first heavy fraction and fractionating it into an intermediate fraction and a second heavy fraction; The first heavy fraction and the intermediate fraction are individually contacted with a hydrodesulfurization catalyst and hydrogen under conditions of simultaneous fractionation and reaction to react organic sulfur, including organic sulfides from the light fraction, with hydrogen to form H ₂ S and hydrocarbons. To form; Recovering an intermediate fraction with reduced sulfur content relative to the first heavy feed and combining the intermediate fraction with the light fraction; Recover the second heavy fraction with reduced sulfur content relative to that of the first heavy feed, ASTM D-86 95% higher than the end point of the intermediate and light fraction combination and lower than the ASTM D-86 95% point of the second heavy fraction Combining a portion of the second heavy fraction with a combination of intermediate and light fractions to obtain a point Desulfurization method of catalytic cracking naphtha comprising. The method of claim 1, wherein a portion of the heavy fraction in combination with the light fraction has an ASTM D-86 95% point lower than the D-86 95% point of catalytic cracking naphtha.

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