Installation and integrated hydrotreatment and hydroconversion process with common fractionation section

Abstract

An installation for the hydrotreatment and hydroconversion of hydrocarbon-containing feedstocks, with a common fractionation section, for the production of at least one of the following products: naphtha (light and/or heavy), diesel, kerosene, distillate and residue: comprising at least: at least one hydroconversion reactor, a hot high-pressure separator drum B-1, a cold high-pressure separator drum B-2, at least one hydrotreatment reactor, a cold high-pressure separator drum B-20, a common fractionation section separating a top fraction, an intermediate fraction and a heavy fraction, An integrated hydroconversion and hydrotreatment process implementing said installation.

Claims

1. An installation capable of hydrotreatment and hydroconversion of hydrocarbon-containing feedstocks, having a common fractionation section, and capable of production of at least one of the following products: naphtha (light and/or heavy), diesel, kerosene, distillate and residue, comprising at least: at least one first unit comprising: a first reaction section R-1 comprising at least one hydroconversion reactor; a hot high-pressure separator drum (B-1) operating at a pressure of 1.4 to 35 MPa and a temperature of 200 to 450 C., and comprising a line supplied with effluent originating from the first reaction section (R-1), and liquid effluent which is a heavy fraction of effluent from the first reaction section (R-1); a cold high-pressure separator drum (B-2), operating at a pressure of 1.3 to 35 MPa and a temperature of 20 C. to 100 C., and comprising a line supplied with gaseous flow originating from the hot high-pressure separator drum (B-1), and liquid effluent of which is a light fraction of effluent from the first reaction section R-1; a hot medium-pressure separator drum (B-3), operating at a pressure of 1 to 5 MPa and a temperature of 200 C. to 450 C., and comprising a line supplied with liquid effluent originating from the hot high-pressure separator drum (B-1), and liquid effluent which supplies a drum (B-5); a cold medium-pressure separator drum (B-4), operating at a pressure of 1 to 5 MPa and a temperature of 20 C. to 100 C., and comprising a line supplied with liquid effluent originating from the cold high-pressure separator drum (B-2), and gaseous fraction originating from the hot medium-pressure separator drum (B-3) and liquid effluent of which constitutes a feedstock of the common fractionation section; a hot low-pressure separator drum (B-5), operating at a pressure of 0.2 to 2.5 MPa and a temperature of 200 C. to 450 C., and comprising a line supplied with liquid flow originating from the hot medium-pressure separator drum (B-3), and liquid effluent of which constitutes a feedstock of the common fractionation section; a second unit comprising: a second reaction section R-10 comprising at least one hydrotreatment reactor; a hot high-pressure separator drum (B-10), operating at a pressure of 1.4 to 35 MPa and a temperature of 200 C. to 450 C., and comprising a line supplied with effluent originating from the second reaction section (R-10), and liquid effluent of which is a heavy fraction of effluent from the reaction section (R-10); a cold high-pressure separator drum (B-20), operating at a pressure of 1.3 to 35 MPa and a temperature of 20 C. to 100 C., and comprising a line supplied with gaseous flow originating from the hot high-pressure separator drum (B-10), or directly with effluent originating from the second reaction section (R-10), and liquid effluent which constitutes a light fraction or a mixture of light fraction and heavy fraction from effluent from the second reaction section (R-10) which supplies either a cold medium- or low-pressure separator drum or supplies directly the common fractionation section; a hot medium-pressure separator drum (B-30), operating at a pressure of 1 to 5 MPa and a temperature of 20 C. to 100 C., having a feedstock which liquid flow originating from the hot high-pressure separator drum B-10, a cold medium-pressure separator drum (B-40), operating at a pressure of 1 to 5 MPa and a temperature of 20 C. to 100 C., and comprising a line supplied with liquid flow originating from the cold high-pressure separator drum (B-20), and a line supplied with gaseous flow originating from the hot medium-pressure separator drum (B-30), and with liquid effluent which constitutes a feedstock of the common fractionation section; a hot low-pressure separator drum (B-50), operating at a pressure of 0.2 to 2.5 MPa and a temperature of 200 C. to 450 C., and comprising a line supplied with the liquid flow originating from the hot medium-pressure separator drum (B-30), producing liquid effluent and vapour effluent of which constitute one or more feedstocks of the common fractionation section the common fractionation section comprising: at least one main fractionation column (C-2), making it possible to separate a top fraction, an intermediate fraction and a heavy fraction, said fractions comprising the different products of the first and second units, flow or flows originating from the first unit and flow or flows originating from the second unit being supplied to said common fractionation unit being separate; a separation column (C-1), said separation column (C-1) being separately supplied with: liquid flow originating from the cold high-pressure separator drum (B-2), and optionally gaseous flow originating from the hot low-pressure separator drum (B-5) of the first unit; liquid flow from the cold high-pressure separator drum (B-20), and/or liquid flow from the cold medium-pressure separator drum (B-40), and/or gaseous flow originating from the cold low-pressure separator drum (B-50), of the second unit; the main fractionation column (C-2) being supplied with liquid effluent from said separation column (C-1), separately with liquid flow originating from the hot medium-pressure separator drum (B-30) of the second unit.

2. The installation according to claim 1 in which the common fractionation section also comprises: at least one side-stripping column (C-4), (C-5) or (C-6), supplied with a product of the intermediate fraction originating from the main fractionation column (C-2), making it possible to separate a top gaseous fraction and a bottom liquid fraction, a pipe making it possible to send said top gaseous fraction to the main fractionation column (C-2); an exchanger (E4) cooling said bottom liquid fraction of said side-stripping column; an outlet pipe for cooled bottom liquid fraction.

3. The installation according to claim 2, comprising a section C-7 allowing treatment of acid gases, said section (C-7) comprising an amine absorber or a washing column, supplied with at least a part of a top fraction originating from the main fractionation column (C-2) containing residual acid gases.

4. The installation according to claim 1 comprising a section for recovery of liquefied petroleum gases comprising one or more fractionation columns, supplied with at least a part of a top fraction originating from the main fractionation column (C-2) containing residual acid gases, or with a flow originating from the section for the treatment of the acid gases (C7).

5. The installation according to claim 1, in which one of the reaction sections (R1) or (R10) comprises a hydroisomerization section including a catalytic dewaxing unit, comprising at least one catalytic bed of catalyst comprising a zeolite, a hydrogenating/dehydrogenating function, and an acid function.

6. The installation according to claim 1, in which the first unit is a hydrocracking unit and the second unit a diesel hydrodesulphurization unit.

7. The installation according to claim 1, in which the first unit is a residue or distillate or deasphalted oil ebullating bed hydroconversion unit, and the second unit is a vacuum distillate, or diesel or kerosene hydrodesulfurization unit.

8. The installation according to claim 7, in which the first unit is a deasphalted oil ebullating bed hydroconversion unit, and the second unit is a vacuum distillate hydrodesulfurization unit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1: Layout of a hydrocracking unit according to the prior art

(2) FIG. 2: Layout of a diesel hydrotreatment unit according to the prior art

(3) FIG. 3: Installation according to the invention with shared fractionation of the diesel hydrocracking and hydrotreatment units and common fractionation section with separation column C1 treating the light fractions.

(4) FIG. 4: Installation according to the invention with shared fractionation of the diesel hydrocracking and hydrotreatment units and common fractionation section without separation column C1 treating the light fractions.

DESCRIPTION OF THE FIGURES

(5) FIG. 1:

(6) FIG. 1 shows a hydrocracking unit implemented according to the prior art.

(7) The feedstock 1 composed of hydrocarbons of oil origin or synthetic hydrocarbons from a mineral or biological source is mixed with hydrogen then sent into a hydrocracking section. This section can comprise one or more fixed-bed or ebullating-bed reactors. Each reactor can comprise one or more catalyst beds carrying out hydrocracking of the hydrocarbons in the feedstock to lighter hydrocarbons.

(8) The addition of hydrogen is supplied via the line 2 and the compressor K-2 then the line 3, and mixed with the recycled hydrogen originating from the compressor K-1 via the line 16 before being mixed with the feedstock 1.

(9) The mixture is introduced into a feedstock-effluent exchanger (E-1) via the line 4. The exchanger E-1 makes it possible to preheat the feedstock by means of the effluent from the hydrocracking reactor R-1. After this exchange, the feedstock is conveyed via the line 5 into a furnace F-1 making it possible to reach the temperature level necessary for the hydrocracking reaction, then the hot feedstock is sent, via the line 6, into at least one reactor R-1 comprising, for example, a hydroprocessing or hydrocracking catalyst.

(10) The effluent from the reaction section at the outlet from the reactor R-1 is sent to the exchanger E-1, then via the line 11 to the hot high-pressure separator drum B-1. A gaseous fraction is separated in this drum and recovered via the line 12. The hydrocracked liquid fraction is recovered at the bottom via the line 20.

(11) The gaseous fraction from the hot high-pressure separator drum B-1 comprises unreacted hydrogen, any H.sub.2S formed during the reaction, as well as light hydrocarbons originating from the side reactions of the hydrocracking reaction. After cooling in an exchanger E-2 and an air condenser A-1, this fraction is conveyed, via the line 13, into a cold high-pressure separator drum B-2 making it possible to carry out both a gas-liquid separation and optionally a decantation of the aqueous liquid phase, originating from the washing water optionally injected at high pressure upstream of E-2 and/or E-1. The liquid hydrocarbon-containing phase, after expansion in the liquid valve or turbine V-1, is directed into a cold medium-pressure separator drum B-4 via the line 21. The aqueous liquid phase, after expansion in a valve, is also directed into a cold medium-pressure separator drum B-4 via the line 24.

(12) The liquid fraction from the hot high-pressure separator drum B-1, after expansion in the liquid valve or turbine V-2, is directed into a hot medium-pressure separator drum B-3 via the line 20. A gaseous fraction is separated in this drum and recovered via the line 22. Said gaseous fraction comprises unreacted hydrogen, optionally H.sub.2S, as well as, generally, light hydrocarbons originating from the conversion of the hydrocarbons of the feedstock in the reaction section R-1. After cooling in an air condenser A-2, this fraction is conveyed via the line 23, into the cold medium-pressure separator drum B-4.

(13) The gaseous effluent originating from the drum B-4 constitutes a hydrogen-rich gaseous fraction purged via the line 25.

(14) The gaseous fraction originating from the cold high-pressure separator drum B-2 is generally sent via the line 14 to an amine absorber or a washing column C-3 making it possible to remove at least a part of the H.sub.2S that it contains. The gaseous fraction containing hydrogen is then recycled via the lines 15 and 16 to the hydrocracking reactor, after compression by means of the compressor K-1 and mixing with the feedstock 1.

(15) The liquid fraction recovered at the bottom of the hot medium-pressure separator drum B-3 is optionally expanded and directed via the lines 30 and 31 to the hot low-pressure separator drum B-5.

(16) All of these items of equipment and the associated lines can be grouped together in section A.

(17) The liquid effluent originating from the drum B-4 constitutes the light liquid fraction originating from the reaction effluent and supplies the stripper C-1 via the lines 32 and 33 after optionally being preheated in the exchanger E-3.

(18) A gaseous fraction is optionally separated in the drum B-5. This gaseous fraction can then supply the stripper C-1 via the line 34 or be mixed with the liquid fraction originating from B-3 via the line 33.

(19) The stripper C-1 is supplied with the stripping steam via the line 35.

(20) At the top of the stripper, a gaseous fraction (generally called acid gas) is recovered via the line 36, and a naphtha having a final boiling point most often greater than 100 C. via the line 37. The liquid recovered at the bottom of the stripper via the line 39 is sent to the main fractionation column C-2, without it being necessary to reheat it in a furnace or an exchanger.

(21) The liquid fraction recovered at the hot medium-pressure drum B-3 and/or optionally the liquid fraction originating from B-5 constitutes the heavy fraction originating from the reaction effluent and, after preheating in the furnace F-2, supplies the main fractionation column C-2 via the line 38, without being subjected to an operation for separation of the acid gases in a stripping column or a reboiled separation column.

(22) The main fractionation column C-2 is typically operated at low pressure, for example 0.19 MPa at the top of the column. The heat necessary for the separation is preferentially supplied by the temperature of the hot separator drums B-3 and/or B-5. This column C-2 is also supplied with the stripping steam via the line 40.

(23) The top fraction recovered via the line 41 contains the residual acid gases which are compressed in the compressor K-3 before being exported to the acid gas treatment section (generally an amine washing or a washing column) before being directed to a combustible gas network.

(24) The product obtained via the line 50 is constituted by naphtha cuts having a final boiling point most often less than 200 C.

(25) The intermediate fraction originating from the main fractionation column has its properties adjusted in the side column C-4. Said side column is supplied with a stripping fluid, for example steam. The intermediate fraction is extracted via the line 51, then cooled, for example, by means of an exchanger E-4, then recovered via the line 52. It is, for example, a gasoil cut having a distillation temperature at 95% by volume less than 360 C.

(26) The heavy fraction originating from the main fractionation column via the line 53 is also cooled by means of the exchanger E-5, for example. The fraction thus obtained via the line 55 is a vacuum gasoil having cut points close to the initial feedstock.

(27) FIG. 2:

(28) FIG. 2 shows a diesel hydrotreatment unit implemented according to the prior art.

(29) The feedstock 101 composed of hydrocarbons of oil origin or synthetic hydrocarbons from a mineral or biological source is mixed with hydrogen then sent into a hydrotreatment section. This section can comprise one or more reactors, generally fixed-bed or ebullating-bed. Each reactor can comprise one or more catalyst beds carrying out the hydrotreatment of the feedstock.

(30) The addition of hydrogen is supplied via the line 102 and the compressor K-20 then the line 103, and mixed with the recycled hydrogen originating from the compressor K-10 via the line 116 before being mixed with the feedstock 101.

(31) The mixture is introduced into a feedstock-effluent exchanger (E-10) via the line 104. The exchanger E-10 makes it possible to preheat the feedstock by means of the effluent from the hydrotreatment reactor R-10. After this exchange, the feedstock is conveyed via the line 105 into a furnace F-10 making it possible to reach the temperature level necessary for the hydrotreatment reaction, then the hot feedstock is sent, via the line 106, into at least one reactor R-10 generally comprising at least one hydrodesulphurization catalyst.

(32) The effluent from the reaction section at the outlet from the reactor R-10 is sent to the exchanger E-10, then via the line 110 to the hot high-pressure separator drum B-10. A gaseous fraction is separated in this drum and recovered via the line 112. The hydrotreated liquid fraction is recovered at the bottom via the line 120. Said gaseous fraction comprises unreacted hydrogen, any H.sub.2S formed during the reaction, as well as light hydrocarbons originating from the side reactions of the hydrotreatment reaction. After cooling in an exchanger E-20 and an air condenser A-10, this fraction is conveyed, via the line 113, into a cold high-pressure separator drum B-20 making it possible, both to carry out a gas-liquid separation and optionally a decantation of the aqueous liquid phase, originating from the washing water optionally injected at high pressure upstream of E-20 and/or E-10. The liquid hydrocarbon-containing phase, after expansion in the liquid valve or turbine V-10, is directed into a cold medium-pressure separator drum B-40 via the line 121. The aqueous liquid phase, after expansion in a valve, is also directed into a cold medium-pressure separator drum B-40 via the line 124.

(33) The liquid effluent originating from the drum B-10, after expansion in the liquid valve or turbine V-20, is directed into a hot medium-pressure separator drum B-30 via the line 120. A gaseous fraction is separated in this drum and recovered via the line 122. Said gaseous fraction comprises unreacted hydrogen, optionally H.sub.2S, as well as, generally, light hydrocarbons. After cooling in an air condenser A-20, this fraction is conveyed via the line 123, into the cold medium-pressure separator drum B-40.

(34) The gaseous effluent originating from the drum B-40 constitutes a hydrogen-rich gaseous fraction purged via the line 125.

(35) The gaseous fraction originating from the cold high-pressure separator drum B-20 is generally sent via the line 14 to an amine absorber or a washing column C-30 making it possible to remove at least a part of the H.sub.2S that it contains. The gaseous fraction containing hydrogen is then recycled via the lines 115 and 116 to the reaction section, after compression by means of the compressor K-10 and mixing with the feedstock 101.

(36) All of these items of equipment and associated lines can be grouped together in section B.

(37) The liquid effluent originating from the drum B-40 constitutes the light liquid fraction originating from the reaction effluent and supplies the stripper C-10 via the lines 132 and 133 after optionally being preheated in the exchanger E-30.

(38) The liquid fraction recovered at the bottom of the hot medium-pressure drum B-30 constitutes the heavy liquid fraction originating from the reaction effluent. It supplies the stripper C-10 via the lines 130 and 131 after mixing with the light liquid fraction originating from the drum B-40.

(39) The stripper C-10 is supplied with the stripping steam via the line 135.

(40) At the top of the stripper, a gaseous fraction (generally called acid gas) is recovered via the line 136, and a naphtha having a final boiling point most often greater than 100 C. and less than 200 C. via the line 137. The liquid recovered at the bottom of the stripper via the line 139 is sent to storage via the line 142 after cooling in the exchangers E-40, E-50 and in the air condenser A-30.

(41) FIG. 3:

(42) FIG. 3 shows the installation according to the invention with a common fractionation section comprising an atmospheric separation column C-1 (stripper) treating the light fractions and a main atmospheric fractionation column.

(43) Section A of the hydrocracking unit is identical to section A described in FIG. 1 and section B of the diesel hydrotreatment unit is identical to section B in FIG. 2. The liquid effluent originating from cold medium-pressure separator drum B-4 constitutes the light liquid fraction originating from the reaction effluent from the hydrocracking unit and supplies the stripper C-1 via the lines 32 and 33 after optionally being preheated in the exchanger E-3.

(44) A gaseous fraction is optionally separated from the heavy fraction originating from the reaction effluent from the hydrocracking unit in the hot low-pressure drum B-5.

(45) This gaseous fraction can then supply the stripper C-1 via the line 34 or be mixed with the liquid fraction originating from B-3 via the line 33.

(46) The liquid effluent originating from the drum B-40 constitutes the light liquid fraction originating from the reaction effluent of the diesel hydrotreatment unit and supplies the stripper C-1 via the lines 132 and 133 after being preheated in the exchanger E-30.

(47) The stripper C-1 is supplied with the stripping steam via the line 35.

(48) At the top of the stripper, a gaseous fraction (generally called acid gas) is recovered via the line 36, and a naphtha having a final boiling point most often greater than 100 C. via the line 37. The liquid recovered at the bottom of the stripper via the line 39 is sent to the main fractionation column C-2, without it being necessary to reheat it in a furnace or an exchanger.

(49) The liquid fraction recovered at the hot medium-pressure drum B-3 and/or optionally the liquid fraction originating from B-5 constitutes the heavy fraction originating from the reaction effluent from the hydrocracking unit and, after preheating in the furnace F-2, supplies the main fractionation column C-2 via the line 38, without being subjected to an operation for the separation of the acid gases in a stripping column or a reboiled separation column.

(50) The liquid fraction recovered at the bottom of the hot medium-pressure drum B-30 constitutes the heavy liquid fraction originating from the reaction effluent from the diesel hydrotreatment unit and directly supplies the main fractionation column C-2 via the line 131, without being subjected to an operation for the separation of the acid gases in a stripping column or a reboiled separation column. The supply takes place at a separate level from the supply originating from the hydrocracking unit. The supply can be introduced either above or below the supply from the hydrocracking unit, but must be separate.

(51) The main fractionation column C-2 is typically operated at low pressure, for example 0.29 MPa at the top of the column. The heat necessary for the separation is preferentially supplied by the temperature of the hot separator drums B3 and/or B-5 and B-30 and optionally B-50. This column C-2 is also supplied with stripping steam via the line 40.

(52) The top fraction recovered via the line 41 contains the residual acid gases which are compressed in the compressor K-3 before being exported to the acid gas treatment section (generally an amine washing or a washing column) before being directed to a combustible gas network.

(53) The product obtained via the line 50 is constituted by naphtha cuts having a final boiling point most often less than 200 C.

(54) The intermediate fraction originating from the main fractionation column has its properties adjusted in the side-stripping column C-4. Said column is supplied with a stripping fluid. The intermediate fraction is extracted via the line 51, then cooled, for example, by means of an exchanger E-4. It is, for example, a gasoil cut having a distillation temperature at 95% by volume less than 360 C. The intermediate fraction is constituted by the mixture of the intermediate fraction originating from the hydrocracking unit and the intermediate fraction originating from the diesel hydrotreatment unit.

(55) The heavy fraction originating from the main fractionation column via the line 53 is also cooled by means of the exchanger E-5, for example. The fraction thus obtained via the line 55 is a vacuum gasoil having cut points close to the initial feedstock of the hydrocracking unit.

(56) FIG. 4 shows the embodiment in which the common fractionation section does not contain a column for separation of the light fractions (stripper or stabilization column) C-1. The common fractionation section comprises only one main atmospheric fractionation column C-2 treating the effluents from two units independent of each other and a side-stripping column C-4.

(57) Said column is then supplied: on the one hand, with the light flow or flows originating from the first unit: for example with the liquid from the cold high-pressure separator drum B-2, and/or from the cold medium-pressure separator drum B-4 via the line 33, and optionally the gaseous flow originating from the hot low-pressure separator drum B-5 via the line 38. These flows originating from the reaction effluent from the first unit are supplied separately from each other. on the other hand, with the light flow or flows originating from the drums operating at low temperature of the second unit: for example either directly with the liquid from the cold high-pressure separator drum B-20, or with the liquid from the cold medium-pressure separator drum B-40, if this exists, via the line 133 and optionally with the gaseous flow originating from the cold low-pressure separator drum B-50, if this exists (not shown here). The flows originating from the reaction effluent from the second unit are supplied separately and are not mixed with the flows originating from the first unit. Typically, the supplies are placed with respect to each other in such a way that the cuts are increasingly heavy from the top to the bottom of the column. on the one hand, with the heavy flow or flows originating from the first unit: for example with the liquid flow originating from the hot high-pressure separator drum B-1, and/or from the hot medium-pressure separator drum B-3, and/or from the hot low-pressure separator drum B-5, via the line 34. Typically, the supplies are placed with respect to each other in such a way that the cuts are increasingly heavy from the top to the bottom of the column. on the other hand, with the heavy flow or flows originating from the second unit, i.e. the liquid flows originating from the hot drums if said drums exist: for example with the liquid flow originating from the hot high-pressure separator drum B-10, and/or from the hot medium-pressure separator drum B-30, and/or from the hot low-pressure separator drum B-50, via the line 131. The light and heavy flows originating from the separation of the reaction effluent from the second unit are supplied separately and are not mixed with the flows originating from the first unit. Typically, the supplies are placed with respect to each other in such a way that the cuts are increasingly heavy from the top to the bottom of the column.

(58) The top fraction recovered via the line 41 contains the residual acid gases which are compressed in the compressor K-3 before being exported to the acid gas treatment section (generally an amine washing or a washing column) before being directed to a combustible gas network.

(59) The product obtained via the line 50 is constituted by naphtha cuts having a final boiling point most often less than 200 C.

(60) The intermediate fraction originating from the main fractionation column has its properties adjusted in the side-stripping column C-4. Said column is supplied with a stripping fluid. The intermediate fraction is extracted via the line 51, then cooled, for example, by means of an exchanger E-4. It is, for example, a gasoil cut having a distillation temperature at 95% by volume less than 360 C. The intermediate fraction is constituted by the mixture of the intermediate fraction originating from the hydrocracking unit and the intermediate fraction originating from the diesel hydrotreatment unit.

(61) The heavy fraction originating from the main fractionation column via the line 53 is also cooled by means of the exchanger E-5, for example. The fraction thus obtained via the line 55 is a vacuum gasoil having cut points close to the initial feedstock of the hydrocracking unit.

(62) A furnace F-2 optionally makes it possible to heat the feedstock or feedstocks supplying the fractionation column C-2. This column is supplied with a stripping fluid at the bottom of the column, generally steam, introduced via the line 40.

EXAMPLES

Example 1 (According to the Prior Art)

(63) The process implemented in the example involves: a hydrocracking unit for a hydrocarbon-containing feedstock constituted by a mixture of vacuum distillate and heavy gasoil originating from a coker unit (HCGO) with a capacity of 31 0003 BPSD, a diesel hydrotreatment unit for a hydrocarbon-containing feedstock constituted by a mixture of gasoil (Straight Run GO) and light vacuum distillate (LVGO) and light gasoil originating from a coker unit (LCGO) with a capacity of 33,500 BPSD.

(64) The role of the reaction section of the hydrocracking unit is to crack, as well as to desulphurize, denitrogenize and saturate the olefins in the feedstock.

(65) The role of the reaction section of the diesel hydrotreatment unit is to desulphurize, denitrogenize and saturate the olefins in the feedstock.

(66) The feedstocks used in this example have the following properties.

(67) TABLE-US-00001 TABLE 1 properties of the feedstocks Diesel Properties Hydrocracking Hydrotreatment Unit Unit Flow rate, t/h 186.3 base 100 198.8 base 100 = 106.7 Density @ 15 C., kg/m.sup.3 923 899 Molecular Weight, kg/mol 372 223 Sulphur content, % by weight 2.2 2.6 Nitrogen content, ppm by 1,800 1,600 weight Carbon residue, Conradson 1.0 max method, % by weight ASTM D86 Distillation, vol % IBP, C. 313 198 10%, C. 362 236 30%, C. 386 268 50%, C. 406 297 70%, C. 438 324 90%, C. 488 353 FBP, C. 542 396

(68) The hydrocracking and diesel hydrotreatment units are first implemented independently of each other.

(69) The layout of the hydrocracking unit is as follows: reaction section in two steps, then separation section common to the two steps, then fractionation section, constituted by a stripping column and an acid fractionation column.

(70) The stripper C-1 is supplied with the light phase originating from the reaction section originating from the mixture of liquid from the cold MP separator drum B-4 with the vapour phase from the hot LP separator drum B-5.

(71) The atmospheric fractionation column is supplied with the liquid from the bottom of the stripper and with the heavy fraction originating from the reaction section constituted by the liquid from the hot LP separator drum B-5.

(72) The fractionation column is constituted by a main column and two side strippers, one C-4 for the kerosene cut (150 C.-193 C.) and the other C-5 for the gasoil cut (193 C.-371 C.).

(73) The products from the fractionation column are an unconverted oil (UCO), gasoil and kerosene which are mixed with the diesel pool and non-stabilized naphtha that will be treated in a downstream section.

(74) The layout of the diesel hydrotreatment unit is as follows: reaction section, then separation section, then fractionation section constituted by a stripping column that produces a non-stabilized naphtha cut and a gasoil cut conforming to the specifications, sent to the diesel pool. The stripper C-10 is supplied with the mixture of the light fraction originating from the reaction section, constituted by the liquid from the cold MP separator drum B-40 and the heavy fraction originating from the reaction section constituted by the liquid from the hot MP separator drum B-30 (cf. FIG. 2).

(75) The operating conditions of the reaction sections are as follows:

(76) TABLE-US-00002 TABLE 2 Operating conditions of the reaction sections: Diesel Hydrotreatment Unit Hydrocracking Overall hourly space velocity 1.0 1.7 (HDT 1.sup.st stage) of liquid feedstock, h.sup.1 3.00 (HCK 1.sup.st stage) 2.0 (HCK 2.sup.nd stage)

(77) The operating conditions of the separation section of each of the two units are as follows:

(78) TABLE-US-00003 TABLE 3 Operating conditions for the separator drums Diesel Hydrocracking Hydrotreatment Operating Separation Separation parameters Section Section Hot High Pressure Separator Temperature C. 330 275 Pressure MPa g 13.61 13.00 Cold High Pressure Separator Temperature C. 55 55 Pressure MPa g 13.6 12.70 Hot Medium Pressure Separator Temperature C. 337 283 Pressure MPa g 2.63 2.58 Cold Medium Pressure Separator Temperature C. 55 77 Pressure MPa g 2.55 2.55 Hot Low Pressure Separator Temperature C. 339 Pressure MPa g 0.96

Example 2 (According to the Invention

(79) The two units are then implemented, according to the invention, with a common fractionation section where the different liquid and gaseous flows originating from the separator drums are supplied to the suitable points in the fractionation section.

(80) This confers the arrangement according to FIG. 3 but with two side-strippers: a side-stripper C-4 on the kerosene cut and a side-stripper C-5 on the diesel cut, the products on which are mixed before going to diesel storage.

(81) The stripper C-1 is supplied: with the light phase originating from the reaction section of the HCK, originating from the mixture of liquid from the cold MP separator drum B-4 with the vapour phase from the hot LP separator drum B-5 and with the light fraction originating from the reaction section of the HDT, constituted by the liquid from the cold MP separator drum B-40.

(82) The fractionation column is supplied: with the liquid from the bottom of the stripper C-1 with the heavy fraction originating from the reaction section of the HCK constituted by the liquid from the hot LP separator drum B-5, and with the heavy fraction originating from the reaction section of the HDT constituted by the liquid from the hot MP separator drum B-30.

(83) The operating conditions of the columns are summarized in Table 4.

(84) TABLE-US-00004 TABLE 4 Operating conditions of the fractionation sections: Diesel Diesel Hydrotreatment + Hydrocracking Hydrotreatment Hydrocracking Fractionation Fractionation Fractionation Operating parameters Section Section Section Stripping column Top temperature C. 118 180 122 Reflux temperature C. 55 222 55 Bottom temperature C. 178 270 180 Top pressure MPa 0.90 1.36 0.90 Number of actual trays 13 30 18 Light fraction from the HCK Tray 6 Tray 6 Light fraction from the HDT Tray 6 Tray 8 Heavy fraction from the HDT Main Fractionation Column Top temperature C. 114 112 Reflux temperature C. 45 45 Bottom temperature C. 352 344 Top pressure MPa 0.19 0.19 Number of actual trays 86 86 Kerosene Draw-off Tray 27 Tray 27 Liq bottom stripper C-1 Tray 30 Tray 30 Heavy fraction from the HDT Tray 40 Gasoil draw-off Tray 42 Tray 42 Heavy fraction from the HCK Tray 66 Tray 66

(85) The properties of the finished products are compared according to the different fractionation layouts.

(86) TABLE-US-00005 TABLE 5 Property of the finished products Units simulated separately according to the prior art According to Properties of the invention the mixture of Common the products of Diesel Dedicated Dedicated Hydrocracking Hydrotreatment Fractionation Fractionation and Diesel and Fractionation Hydrotreatment Hydrocracking Hydrotreatment Hydrocracking Non-stabilized Naphtha Flow rate, t/h 0.8 10.9 11.7 9.5 Density @ 15 C., kg/m.sup.3 749 720 722 721 Molecular Weight, kg/mol 92.32 97.05 96.65 97.06 Final boiling point, T C. 214 144 183 144 Sulphur content, ppm by weight 50 max 50 max 50 max 50 max Diesel + Kerosene Flow rate, t/h 105.5 80.7 186.2 186.2 Density @ 15 C., kg/m.sup.3 839 822 830 830 Sulphur content, ppm by weight 10 max 10 max 10 max 10 max Calculated cetane number 52 59 56 56 (ASTM D4737) Viscosity @ 40 C., cSt 2.6 2.6 2.6 2.6 Flash point, C. 55 57 58 62 Distillation ASTM D86 Recovered @ 250 C., vol % 38 36 38 39 Recovered @ 350 C., vol % 94 93 96 96 95 vol % Recovered, C. 353 355 348 346 Unconverted VGO Flow rate, t/h 0.5 0.5 0.5 Density @ 15 C., kg/m.sup.3 844 844 844 Sulphur content, ppm by weight 10 max 10 max 10 max Nitrogen content, ppm by 5 max 5 max 5 max weight Pour point 40 max 40 max 40 max Viscosity @ 100 C., cSt 5.8 5.8 5.9 Metals (Ni + V), ppm by weight 0.1 max 0.1 max 0.1 max ASTM D1160 Distillation, vol % IBP, C. 384 384 392 10%, C. 417 417 419 30%, C. 445 445 445 50%, C. 470 470 470 70%, C. 500 500 500 90%, C. 535 535 535 FBP, C. 564 564 564

(87) Table 5 shows that the finished products obtained in the process according to the invention with a common fractionation section are equivalent in quantity and quality to the finished products obtained by mixing the products of the two simulated units according to the prior art each with their fractionation section with regard to the Diesel and Kerosene mixture and for the unconverted VGO.

Example 3 (According to the Invention

(88) The Diesel hydrotreatment unit described in Example 1 with the feedstock described in Example 1 produces a Diesel+Kerosene cut that satisfies the properties of the Diesel pool grade A to D. With the same feedstock, this unit cannot produce a diesel conforming to the winter specifications for gasoil in standard EN590:2013 of July 2013, for temperate climates. Indeed, according to this standard, the maximum cold filter plugging point varies from +5 C. for Grade A to 15 C. for Grade E and 20 for Grade F, which corresponds to the grades typically used when the outside temperature is lower (in winter).

(89) TABLE-US-00006 TABLE 6 Gasoil specifications in standard EN 590:2013 of July 2013: General specifications Density @ 15 C., kg/m.sup.3 820-845 Sulphur content, ppm by weight 10 max Calculated cetane number 46 min Viscosity @ 40 C., cSt 2.5-4 Flash point, C. 55 min Distillation ASTM D86 Recovered @ 250 C., vol % 65 max Recovered @ 350 C., vol % 85 min 95 vol % Recovered, C. 360 max

(90) TABLE-US-00007 TABLE 7 Specifications of the cold temperature plugging point of the gasoil for temperate climates according to standard EN 590: 2013 of July 2013: Grade A B C D E F Maximum cold filter +5 0 5 10 15 20 plugging point (CFPP), C.

(91) According to the invention, the diesel hydrotreatment unit and the hydrocracking unit are implemented as in Example 2 with a common fractionation section where the different liquid and gaseous flows originating from the drums are supplied separately to the suitable points in the fractionation section. The same diesel feedstock sent to the diesel hydrotreatment unit makes it possible to produce various qualities of diesel+kerosene including that conforming to grade E by adjusting the cut point of the diesel in the common fractionation section.

(92) The properties of the diesel+kerosene cut obtained according to the invention with two cut points different to the main fractionation are summarized in Table 7 below.

(93) TABLE-US-00008 TABLE 8 properties of Diesel + Kerosene Cut point 1 Cut point 2 Flow rate, t/h 186.2 173.9 Density @ 15 C., kg/m.sup.3 830 829 Sulphur content, ppm by weight 10 max 10 max Calculated cetane number 56 52 Viscosity @ 40 C., cSt 2.6 2.5 Flash point, C. 62 60 Cold filter plugging point (CFPP), 10 18 C. Distillation ASTM D86 Recovered @ 250 C., vol % 39 44 Recovered @ 350 C., vol % 96 96 95 vol % Recovered, C. 346 340 Corresponding grade: D E

Example 4

(94) Example 4 shows the embodiment described in FIG. 4 with a common fractionation section comprising an atmospheric fractionation column C-2 without a column for the separation of light fractions C-1.

(95) The process implemented in the example involves: a hydrocracking unit of the same capacity and which treats the same feedstocks as the hydrocracking unit in Example 1 with the same objective and with the same operating conditions for the reaction section. a diesel hydrotreatment unit of the same capacity and treating the same feedstocks as the diesel hydrotreatment unit in Example 1 with the same objective and with the same operating conditions for the reaction section.

(96) The hydrocracking and diesel hydrotreatment units are first implemented independently of each other.

(97) The layout of the hydrocracking unit is as follows: reaction section in two steps, then separation section, then fractionation section, constituted by an acid fractionation column C-2 without a column for the separation of the light fractions C-1.

(98) The atmospheric fractionation column is supplied with the heavy fraction originating from the reaction section constituted by the liquid from the hot HP separator drum B-4, by the light fraction originating from the reaction section originating from the liquid from the hot LP separator drum B-5 and from the vapour phase from the hot LP separator drum B-5.

(99) The fractionation column C-2 is constituted by a main column and two side strippers, one C-4 for the kerosene cut (150 C.-193 C.) and the other C-5 for the gasoil cut (193 C.-371 C.).

(100) The products from the fractionation column are an unconverted oil (UCO), gasoil and kerosene which are mixed with the diesel pool and non-stabilized naphtha that will be treated in a downstream section and an acid gas fraction.

(101) The layout of the diesel hydrotreatment unit is identical to the layout of the diesel hydrotreatment unit in Example 1.

(102) The operating conditions of the separation section of each of the two units are identical to the operating conditions of the separation section of the units in Example 1:

(103) The two units are then implemented, according to the invention, with a common fractionation section where the different liquid and gaseous flows originating from the separator drums are supplied to suitable places in the main fractionation column, without a column for separation of the light fractions, according to the embodiment described in FIG. 4, but with two side-strippers: a side-stripper C-4 on the kerosene cut and a side-stripper C-5 (not shown) on the diesel cut the products of which are mixed before going to diesel storage.

(104) According to the invention, the fractionation column C-2 is supplied: with the light phase originating from the reaction section of the hydrocracking section, originating from the mixture of liquid from the cold MP separator drum B-4 with the vapour phase from the hot LP separator drum B-5 with the light fraction originating from the reaction section of the hydrotreatment section, constituted by the liquid from the cold MP separator drum B-40, with the heavy fraction originating from the reaction section from the hydrocracking section, constituted by the liquid from the hot LP separator drum B-5, and with the heavy fraction originating from the reaction section of the hydrotreatment section, constituted by the liquid from the hot MP separator drum B-30.

(105) The operating conditions of the columns are summarized in Table 9.

(106) TABLE-US-00009 TABLE 9 Operating conditions of the fractionation sections: Common Diesel Diesel Hydrotreatment + Hydrocracking Hydrotreatment Hydrocracking Fractionation fractionation Fractionation Operating parameters Section Section Section Stripping column Top temperature C. 180 Reflux temperature C. 222 Bottom temperature C. 270 Top pressure MPa 1.36 Number of actual trays 30 Light fraction from the HCK Light fraction from the HDT Tray 6 Heavy fraction from th eHDT Main Fractionation Column Top temperature C. 115 109 Reflux temperature C. 45 45 Bottom temperature C. 352 354 Top pressure MPa 0.19 0.19 Number of actual trays 86 86 Kerosene Draw-off Tray 27 Tray 30 Gasoil draw-off Tray 42 Tray 45 Light fraction from the Diesel Tray 35 Hydrotreatment Heavy fraction from the Diesel Tray 40 Hydrotreatment Cold light fraction from the Tray 40 Tray 40 Hydrocracking Hot light Fraction from the Tray 50 Tray 50 Hydrocracking Heavy fraction from the Tray 66 Tray 66 Hydrocracking

(107) The properties of the finished products are compared according to the different fractionation layouts.

(108) TABLE-US-00010 TABLE 10 Property of the finished products Units simulated separated according to the prior According to art the invention Properties of Common the mixture of Diesel the products of Hydrotreatment Dedicated Dedicated Hydrocracking and Hydrotreatment Hydrocracking and Diesel Hydrocracking fractionation Fractionation Hydrotreatment Fractionation Non-stabilized Naphtha Flow rate, t/h 0.8 10.9 11.7 9.9 Density @ 15 C., 749 720 722 719 kg/m.sup.3 Molecular Weight, 92.32 97.05 65. 96 97.16 kg/mol Final boiling point, 214 144 183 144 T C. Sulphur content, 50 max 50 max 50 max 50 max ppm by weight Diesel + Kerosene Flow rate, t/h 105.5 80.7 186.2 186.2 Density @ 15 C., 839 822 830 830 kg/m.sup.3 Sulphur content, 10 max 10 max 10 max 10 max ppm by weight Calculated cetane 52 59 56 56 number (ASTM D4737) Viscosity @ 40 C., 2.6 2.6 2.6 2.6 cSt Flash point, C. 55 57 58 62 Distillation ASTM D86 Recovered @ 38 36 38 39 250 C., vol % Recovered @ 94 93 96 96 350 C., vol % 95 vol % 353 355 348 346 Recovered, C. Unconverted VGO Flow rate, t/h 0.5 0.5 0.5 Density @ 15 C., 844 844 844 kg/m.sup.3 Sulphur content, 10 max 10 max 10 max ppm by weight Nitrogen content, 5 max 5 max 5 max ppm by weight Pour point 40 max 40 max 40 max Viscosity @ 5.8 5.8 5.9 100 C., cSt Metals (Ni + V), 0.1 max 0.1 max 0.1 max ppm by weight ASTM D1160 Distillation, vol % IBP, C. 384 384 390 10%, C. 417 417 416 30%, C. 445 445 446 50%, C. 470 470 472 70%, C. 500 500 500 90%, C. 535 535 535 FBP, C. 564 564 564

(109) Table 10 shows that the finished products obtained according to the invention with a common fractionation section constituted by a main fractionation column and two side stripping columns, are equivalent in quantity and quality to the finished products obtained by mixing the products of the two units implemented according to the prior art each with their fractionation section with regard to the Diesel and Kerosene mixture and for the unconverted VGO.