Process for the activation and start-up of catalysts for deep hydrodesulfurization of middle distillates

Abstract

The present invention deals with activation and start-up procedures of catalysts for the deep HDS of middle distillates for producing ultra low sulfur diesel (ULSD), consisting of two in situ activation stages: at stage 1, TGA is applied, and at stage 2, DMDS is used; kerosene is the transport means at these stages, which are carried out under given temperature and pressure conditions, and feedstock and hydrogen flows at established times. After the activation of the catalyst in situ, the stabilization stage takes place under selected temperature and pressure conditions, feedstock and hydrogen flow at established times, with which the stabilization of the highly dispersed metallic sulfides is achieved and, in this way, the activity of the catalysts removing contaminants for the production of ULSD is increased.

Claims

1. A method for the activation and start-up of catalysts for the deep hydrodesulfurization (HDS) of middle distillates, which comprises the following stages: two activation stages: stage 1, where thioglycolic acid (TGA) is applied, and stage 2, where dimethyl disulfide (DMDS) is applied; a catalyst stabilization stage, where the catalyst is stabilized; and a catalytic evaluation stage, where the activity of the catalyst is evaluated.

2. The method according to claim 1, wherein at stages 1 and 2, kerosene is used to transport TGA and DMDS.

3. The method according to claim 1, wherein at stages 1 and 2, hydrogen is fed.

4. The method according to claim 1, wherein at stage 1, the reactor temperature ranges from 200 to 230? C.

5. The method according to claim 1, wherein at stage 1, pressure ranges from 45 to 60 kg/cm.sup.2.

6. The method according to claim 1, wherein at stage 1, the Kero/TGA flow rate ranges from 170 to 190 mL/h.

7. The method according to claim 1, wherein at stage 1, the H.sub.2/oil ratio ranges from 50 to 60 m.sup.3/bbl.

8. The method according to claim 1, wherein at stage 1, time ranges from 4 to 10 h.

9. The method according to claim 1, wherein at stage 2, the temperature ranges from 200-320? C. in a staggered manner.

10. The method according to claim 1, wherein at stage 2, pressure ranges from 45 to 60 kg/cm.sup.2.

11. The method according to claim 1, wherein at stage 2, the Kero/DMDS ranges from 170 to 190 mL/h.

12. The method according to claim 1, wherein at stage 2, the H.sub.2/oil ratio ranges from 50 to 60 m.sup.3/bbl.

13. The method according to claim 1, wherein at stage 2, the time ranges from 8 to 16 h.

14. The method according to claim 1, wherein at the catalyst stabilization stage, the reactor temperature ranges from 300 to 320? C.

15. The method according to claim 1, wherein at the catalyst stabilization stage, the pressure ranges from 45 to 60 kg/cm.sup.2.

16. The method according to claim 1, wherein at the catalyst stabilization stage, the feedstock flow rate ranges from 170 to 190 mL/h.

17. The method according to claim 1, wherein at the catalyst stabilization stage, feedstocks within the interval of middle distillates can be used.

18. The method according to claim 1, wherein at the catalyst stabilization stage, the H.sub.2/oil ratio ranges from 50 to 60 m.sup.3/bbl.

19. The method according to claim 1, wherein at the catalyst stabilization stage, the time ranges from 48 to 72 h.

20. The method according to claim 1, wherein the catalytic evaluation stage comprises activity tests performed under operating conditions effective to evaluate the activity of each catalyst with every feedstock in terms of the deep HDS of middle distillates for producing ultra low sulfur diesel (ULSD), wherein the operating conditions comprise temperature, pressure conditions, liquid hourly space velocity (LHSV), and H.sub.2/oil ratio.

21. The method according to claim 20, the temperature ranges from 335 to 355? C.

22. The method according to claim 20, wherein the pressure ranges from 45 to 60 kg/cm.sup.2.

23. The method according to claim 20, wherein the LHSV ranges from 1.0 to 2.5 h.sup.?1.

24. The method according to claim 20, wherein the H.sub.2/oil ratio ranges from 50 to 60 m.sup.3/bbl.

25. The method according to claim 1, further comprising selecting operating conditions of the two activation stages, the catalyst stabilization stage, and the catalytic evaluation stage for each feedstock type and catalyst.

Description

BRIEF DESCRIPTION OF THE INVENTION DRAWINGS

(1) FIG. 1 shows a diagram of the activation and start-up procedures of the catalysts for the deep hydrodesulfurization of middle distillates.

(2) FIG. 2 displays the reactor employed in the pilot plant tests and the distribution of catalysts and inert materials, where: A=inert material, FG=fiberglass, CAT/B=catalyst/combined bed.

DETAILED DESCRIPTION OF THE INVENTION

(3) This invention is related to activation and start-up procedures of catalysts for the deep hydrodesulfurization of middle distillates through two stages: the first stage refers to the use of a chelating organic additive consisting of TGA and kerosene or straight run gas oil (SRGO) as transport means and the second stage describes the use of a sulfhydration agent consisting of DMDS and kerosene or SRGO as transport means with a sequence given in times and temperature, pressure and space velocity conditions and feedstock type established for each process run with their corresponding efficiencies in the deep hydrodesulfurization of middle distillates regarding the sulfur content in the produced diesel.

(4) In the present invention, as part of the first stage, the use in situ of an organic additive (TGA), whose main characteristic is its chelating effect or complexation of active metals for the stabilization of highly dispersed metallic sulfides, is proposed. The TGA effect complexing Mo allows the transport of reduced Mo.sup.+5 active metallic species.

(5) Another important TGA effect is that the TGA/Mo ratio conditions the chelating effects, which in combination with the organic sulfhydration additive (DMDS) increases the sulfhydration effect of the active metal, i.e. in addition to reduce the length of the MoS.sub.2 sheets, higher catalytic activity of the HDS catalysts reducing the content of sulfur in diesel is generated.

(6) Furthermore, TGA produces the in situ redispersion of active metallic sites, which are formed during the start-up thermal treatments, producing a HDS catalyst with higher catalytic activity and then, with higher activity in the deep hydrodesulfurization to obtain ULSD.

(7) In a second stage, DMDS is used as sulfhydration agent, where one of its most important in situ effects is the absorption of heat released during the exothermal transformation of oxides into metallic sulfides, generating higher dispersion of the active species and higher activity in the deep HDS.

(8) In order to better understand the activation and start-up of a deep HDS catalyst and the use in two stages, first of TGA as chelating organic additive and second of DMDS as a sulfhydration agent, it is divided into the following steps for the case of a pilot plant with a reactor loaded with 75 mL of catalyst: I) Catalyst loading II) Conditioning and hermeticity tests III) Catalyst drying IV) First activation stage V) Second activation stage VI) Catalyst start-up VII) Activity tests
Step I) It consists in the loading of the catalyst or combined bed of catalysts based on the established loading diagram. This diagram specifies: the catalyst(s) and inert material(s) to be loaded, their location in the reactor, corresponding amounts, heights and estimated value(s) of loaded density/densities.
Step II) It consists in the conditioning of the reactor with the loaded catalyst at ambient temperature for the hermeticity test, which is carried out at a preferred pressure from 70 a 75 kg/cm.sup.2 and hydrogen flow preferably from 45 a 75 L/h for a period of time preferably from 2 a 4 h. Once the plant hermeticity has been fully confirmed, the pressure (45-60 kg/cm.sup.2) and hydrogen flow rate (45-75 L/h) are established before starting to increase the reactor temperature to 120? C. at a heating rate of 20-30? C./h.
Step III) Consists in the drying of the catalyst loaded in the reactor at 120? C. under the same pressure and hydrogen flow rate conditions mentioned in Step II for 2-4 h. Once this time is completed, the reactor inlet temperature is increased from 120 to 230? C. at a heating rate of 20-30? C./h, keeping constant pressure and hydrogen flow rate.
Step IV) Consists of a first activation stage at which a mixture consisting of TGA with kerosene or diesel is added at a preferable flow rate from 170 to 190 mL/h for a preferable time from 4 to 10 h, at preferable temperature from 200 to 230? C., preferable pressure from 45 to 60 kg/cm.sup.2 and a preferable H.sub.2/oil ratio from 50 to 60 m.sup.3/bbl.
Step V) Consists of a second activation stage at which a mixture consisting of DMDS with kerosene or diesel is added at a preferable flow rate from 170 a 190 mL/h, at preferable temperature from 200-230? C., at preferable pressure from 45-60 kg/cm.sup.2 with preferable H.sub.2/oil ratio from 50-60 m.sup.3/bbl and preferable time from 8-16 h. Afterward, the temperature is preferably increased from 240-260? C. with a heating rate from 20-30? C./h under the same just established flow, pressure, H.sub.2/oil ratio and time conditions. During this second stage, the temperature continues being increased preferably from 260-280? C. with the same heating rate and same flow rate, pressure, H.sub.2/oil ratio and time conditions. The second activation stage continues increasing the temperature, now at preferable temperature from 280-300? C. with the same heating rate and same flow, pressure, H.sub.2/oil ratio and time conditions. The last part of the second activation stage occurs by increasing the temperature preferably from 300-320? C. with the same heating rate and same flow, pressure, H.sub.2/oil ratio, and time conditions.
Step VI) Consists in the catalyst stabilization and the treatment is just with kerosene or diesel, with preferable flow rate from 170 to 190 mL/h, under the same pressure and H.sub.2/oil ratio conditions mentioned in Step V, at preferable temperature from 300-320? C. for a preferable time from 48 to 72 h. During this time period, the feedstock to be processed, whose characteristics should be within the interval of middle distillate mixtures (see Table 1), is made ready. Once the established time has passed, the temperature is increased to the value estimated as start of run temperature preferably from 300-320 until 335-355? C. with a heating rate from 5-10? C./h.
Step VII) Consists in performing the activity tests of the improved process in the deep HDS for producing ULSD with the following sequence: Activation and start-up conditions Selection of feedstock type (Table 1) Operating conditions: Temperature, pressure, H.sub.2/oil ratio and LHSV Type of deep HDS catalyst (Table 2)

(9) Table 1 shows the physical and chemical characteristics of the processed feedstocks once the improved activation and run process was applied to the catalysts to be evaluated and that are used in the examples developed and shown in this patent.

(10) TABLE-US-00001 TABLE 1 Physical and chemical properties of the feedstocks (C) Feedstocks Properties CI CII CIII CIV Sulfur content (wt. %) 1.137 0.740 1.129 0.998 Nitrogen content (wppm) 118.1 78.1 120.0 126.0 Bromine number 3.69 2.29 1.32 4.34 (g Br/100 g) Aromatics content (wt. %) 27.1 25.9 28.7 27.6 Density at 20? C. (g/mL) 0.8208 0.8243 0.8394 0.8358 Cetane index 48.97 50.94 51.90 52.30 Distillation (vol. %) (? C.) IBP 150.2 159.6 192.7 171.1 10 181.9 195.5 243.5 207.7 30 206.1 219.6 263.1 243.8 50 238.2 247.4 277.8 275.6 70 273.9 278.3 294.5 303.3 90 311.9 320.1 316.0 338.4 EBP 335.8 353.6 336.2 365.8

(11) Table 2 includes the properties of the catalysts before being loaded in the reactor and that were tested in the pilot plant. Evident differences are observed in the surface area, content, and concentration of the active metals: CATI (LM) and CATII (HM) of NiMo and CATIII of CoMo.

(12) TABLE-US-00002 TABLE 2 Properties of the catalysts (CAT) Catalysts Property CATI (LM) CATII (HM) CATIII Specific surface area (m.sup.2/g) 208 64 30 Pore volume (cm.sup.3/g) 0.53 0.10 0.00 Average pore diameter (nm) 10-25 5.4 5.8 Mo (wt. %) 9.71 18.17 15.65 Ni (wt. %) 2.25 4.38 0.02 Co (wt. %) 0.7 3.64 P (wt. %) 1.04 3.13 0.4 Al balance (wt. %) 41.61 22.88 27.43 Size crushing strength (lbf/mm) 3.76 6.28 3.98 Diameter size (mm) 1-3 1-3 1-3 Shape Extrudate Extrudate Extrudate

(13) Table 3 shows the sulfur content values after applying the improved activation and start-up procedures as evidence of the activity of the catalysts in the deep HDS for producing ULSD.

(14) TABLE-US-00003 TABLE 3 Catalytic activity after applying the improved activation and start-up procedures in the deep HDS for producing ULSD CI feedstock Tem- H.sub.2/ perature Pressure oil ratio LHSV S Tests Catalyst (? C.) (kg/cm.sup.2) (m.sup.3/bbl) (h.sup.?1) (wppm) 1 Characteristics 2 CATI(LM) 335 54 60 1.6 18.9 3 345 54 60 1.6 2.1 4 355 54 60 1.6 2.5 5 CATII(HM) 355 54 60 1.6 2.9 6 345 54 60 1.6 1.5 7 CATIII 355 54 60 1.6 18.9 8 345 54 60 1.6 8.4 CII feedstock 9 CATI(LM) 345 54 40.8 1.8 31.8 10 355 54 40.8 1.8 6.2 11 365 54 40.8 1.8 61.0 12 CATII(HM) 345 54 40.8 1.8 36.9 13 355 54 40.8 1.8 3.6 14 365 54 40.8 1.8 2.1 16 CATIII 345 54 40.8 1.8 29.6 17 355 54 40.8 1.8 9.3 18 365 54 40.8 1.8 3.0 CIII feedstock 19 CATI(LM) 345 54 60 1.6 15.9 20 355 54 60 1.6 2.9 21 365 54 60 1.6 0.9 22 CATII(HM) 345 54 60 1.6 7.2 23 355 54 60 1.6 2.7 24 365 54 60 1.6 1.6 25 CATIII 345 54 60 1.6 14.4 26 355 54 60 1.6 4.5 27 365 54 60 1.6 3.2 CIV feedstock 28 CATI(LM) 345 54 60 1.6 34.3 29 355 54 60 1.6 7.7 30 365 54 60 1.6 1.5 31 CATII(HM) 345 54 60 1.6 8.4 32 355 54 60 1.6 4.3 33 365 54 60 1.6 1.1

EXAMPLES

(15) What follows is the description of four practical examples to better understand the present invention without this limiting its scope.

Example 1

(16) Experimental runs were carried out in a pilot plant employing a continuous flow, combined bed reactor with the corresponding hermeticity tests, obtaining the following results:

(17) 1.Load 75 mL of CATII(HM) catalyst and 75 mL of inert A, compacting uniformly as indicated in the reactor diagram (see FIG. 2) with the locations of the catalytic bed and inert A. 2.Adjust the operating pressure at 54 kg/cm.sup.2 with H.sub.2 flow rate of 75 L/h. Start heating up to 120? C. at a heating rate of 20? C./h; once these conditions are reached, they are kept for 2 h. 3.Increase the reactor temperature to 230? C. at a heating rate of 20? C./h. At 230? C., start adding Kero/TGA at 180 mL/h (density at 20? C.=0.8292 g/mL), keeping the pressure at 54 kg/cm.sup.2, adjusting the H.sub.2 flow rate at 40 L/h and keeping these conditions for 6 h. 4.Stop the Kero/TGA blend. At 230? C., feed 155 mL/h of Kero/DMDS (density at 20? C.=0.8292 g/m L), keeping the pressure at 54 kg/cm.sup.2 and H.sub.2 flow rate at 40 L/h for 2 h. 5.Increase the reactor temperature to 250? C. at a heating rate of 20? C./h, pressure of 54 kg/cm.sup.2, 40 L/h of H.sub.2 and 155 mL/h of Kero/DMDS, keeping these conditions for 2 h. 6.Increase the reactor temperature to 270? C. at a heating rate of 20? C./h, pressure of 54 kg/cm.sup.2, 40 L/h of H.sub.2 and 155 mL/h of Kero/DMDS, keeping these conditions for 2 h. 7.Increase the reactor temperature to 290? C. at a heating rate of 20? C./h, pressure of 54 kg/cm.sup.2, 40 L/h of H.sub.2 and 155 mL/h of Kero/DMDS, keeping these conditions for 2 h. 8.Increase the reactor temperature to 315? C. at a heating rate of 20? C./h, pressure of 54 kg/cm.sup.2, H.sub.2 flow rate of 40 L/h and Kero/DMDS flow rate of 155 m L/h, keeping these conditions for 2 h. 9.Stop feeding Kero/DMDS and feed 155 mL/h of kerosene (density at 20? C.=0.8240 g/mL) at 315? C., pressure of 54 kg/cm.sup.2 and 40 L/h of H.sub.2. Perform 6 balances of 8 h each. At the end of each balance, recover 750 mL of product and wash it with a NaOH solution at 10 wt. % with a volume ratio of 1:1 for 30 min. Recover the washed product and the remaining product. Label the samples (8 samples). 10.Catalytic evaluation: once the 8 balances are finished, stop feeding kerosene and feed the process feedstock identified as CII, proceeding as follows: Feed 135 mL/h of CII (density at 20? C.=0.8243 g/mL), (LHSV=1.8 h.sup.?1) Increase the temperature to 365? C. at a heating rate of 5? C./h Keep the pressure at 54 kg/cm.sup.2 Adjust the H.sub.2 flow rate at 40.8 L/h Under these conditions, stabilize the reactor for 8 h 11.Perform 4 balances of 8 h under the following conditions: Temperature at 365? C. Pressure of 54 kg/cm.sup.2 135 mL/h of CII (LHSV=1.8 h.sup.?1) H.sub.2 flow rate of 40.8 L/h 12.At the end of the 4 balances, recover 750 mL of product and wash it with a NaOH solution at 10 wt. % with a volume ratio of 1:1 for 30 min. Recover the washed and non-washed product. Label the samples (4 balances).
The average activity of the deep HDS of the CII feedstock considering 4 balances is in the order of 2.1 wppm of sulfur. 13.After finishing the last 4 balances, stop feeding the CII feedstock and feed the CIV feedstock and perform the following changes: Feed 180 mL/h of CIV (density at 20? C.=0.8603 g/m L), (LHSV=1.6 h.sup.?1) Increase the reactor temperature to 355? C. at a heating rate of 5? C./h Adjust the pressure to 54 kg/cm.sup.2 Adjust the H.sub.2 flow rate to 60 L/h Under these conditions, stabilize the reactor for 8 h. 14.Under previously established conditions, carry out 4 balances of 8 h. 15.At the end of the 4 balances, recover 750 mL of product and wash it with a NaOH solution at 10 wt. % with a volume ratio of 1:1 for 30 min. Recover the washed and non-washed product. Label the samples (4 balances).
The average activity of the deep HDS of the CIV feedstock considering 4 balances is in the order of 4.3 wppm of sulfur.

Example 2

(18) 1.The loading conditions of the CATI (LM) catalyst and inert A are the same as those in Example 1. 2.The Kero/TGA flow and temperature, pressure, H.sub.2 flow and times are the same as those in Example 1. 3.The Kero/DMDS flow and temperature, pressure, H.sub.2 flow and times are the same as those in Example 1. 4. In the case of the Kero stabilization, the procedure, conditions, time and analysis to be done are the same as those in Example 1. 5.In the case of the catalytic evaluation, the CI process feedstock is fed as follows: Adjust the initial pressure in the reactor Feed 115 mL/h of CI until flooding the catalytic bed Increase the reactor pressure to 54 kg/cm.sup.2 Keep these conditions for 1 h Stop feeding CI and keep the conditions for 1 h Start feeding 112 mL/h of CI and H.sub.2 at 29 L/h Increase the reactor temperature to 315? C. at a heating rate of 30? C./h. Start feeding CI at 135 mL/h (LHSV=1.6 h.sup.?1) with pressure at 54 kg/cm.sup.2 and H.sub.2 flow of 60 L/h. Increase the temperature reactor to 335? C. at 5? C./h, keeping a flow rate of 135 m L/h, pressure of 54 kg/cm.sup.2 and H.sub.2 flow of 60 L/h.
Catalytic evaluation of the catalyst CATI (LM) 5.Increase to 345? C. the reactor temperature at a heating rate of 5? C./h and stabilize for 8 h. 6.Perform 4 balances of 8 h each under the previous conditions. 7.Increase the reactor temperature to 355? C. at a heating rate of 5? C./h and stabilize for 8 h. 8.Carry out 4 balances of 8 h each under the previous conditions. 9.At the end of the 4 balances, recover 750 mL of product and wash it with a NaOH solution at 10 wt. % with a volume ratio of 1:1 for 30 min. Recover the washed and non-washed product. Label the samples (4 balances).
The average activity of the deep HDS of the CII feedstock considering 4 balances is in the order of 2.1 wppm of sulfur.

Example 3

(19) 1.Load 75 mL of CATIII catalyst and 75 mL of inert A, compacting uniformly as indicated in the reactor diagram (see FIG. 2) with the location and length of the catalytic bed and location and amount of inert A. 2.Adjust the operating pressure at 54 kg/cm.sup.2 with H.sub.2 flow rate of 75 L/h. Start heating up to 120? C. at a heating rate of 20? C./h; once these conditions are reached, they are kept for 2 h. 3.Increase the reactor temperature to 230? C. at a heating rate of 20? C./h. At 230? C., start adding Kero/TGA at 180 mL/h (density at 20? C.=0.8292 g/mL), keeping the pressure at 54 kg/cm.sup.2 and the H.sub.2 flow rate at 67.9 L/h for 10 h. 4.Stop the Kero/TGA blend. At 230? C., feed 180 mL/h of Kero/DMDS (density at 20? C.=0.8292 g/mL), keeping the pressure at 54 kg/cm.sup.2 and H.sub.2 flow rate at 67.9 L/h. Keep the conditions for 16 h. 5.During the last hour of the 16-h period, recover the sulfhydration product sample and establish the sulfur content. Likewise, recover the outlet gas sample and establish H.sub.2S content. Label the samples. 6.Increase the reactor temperature to 250? C. at a heating rate of 20? C./h, pressure of 54 kg/cm.sup.2, 67.9 L/h of H.sub.2 and 180 mL/h of Kero/DMDS, keeping these conditions for 8 h. 7.During the last hour of the 8-h period, recover the sulfhydration product sample and establish the sulfur content. Likewise, recover the outlet gas sample and establish H.sub.2S content. Label the samples. 8.Increase the reactor temperature to 290? C. at a heating rate of 20? C./h, pressure of 54 kg/cm.sup.2, H.sub.2 flow rate of 67.9 L/h and Kero/DMDS flow rate of 180 mL/h, keeping these conditions for 8 h. 9.During the last hour of the 8-h period, recover the sulfhydration product sample and establish the sulfur content. Likewise, recover the outlet gas sample and establish H.sub.2S content. Label the samples. 10.Increase the reactor temperature to 315? C. at a heating rate of 20? C./h, pressure of 54 kg/cm.sup.2, H.sub.2 flow rate of 67.9 L/h and Kero/DMDS flow rate of 180 mL/h, keeping these conditions for 8 h. 11.During the last hour of the 8-h period, recover the sulfhydration product sample and establish the sulfur content. Likewise, recover the outlet gas sample and establish H.sub.2S content. Label the samples. 12.Stop feeding the Kero/DMDS blend and feed 155 mL/h of kerosene at 315? C., pressure of 54 kg/cm.sup.2 and 67.9 L/h of H.sub.2. Perform 6 balances of 8 h each. At the end of each balance, recover 750 mL of product and wash it with a NaOH solution at 10 wt. % with a volume ratio of 1:1 for 30 min. 13.Increase the reactor temperature to 345? C. at a heating rate of 5? C./h and feed 180 mL/h of feedstock to be stabilize (Kero), keeping the pressure at 54 kg/cm.sup.2 and the H.sub.2 flow at 69.7 L/h. 14.Catalytic evaluation: at 355? C. as reactor temperature, stop feeding the feedstock to be stabilized (Kero) and feed the CIII process feedstock as follows: Feed 120 mL/h of CI (density at 20? C.=0.8203 g/mL), (LHSV=1.6 h.sup.?1) Keep the pressure at 54 kg/cm.sup.2 Adjust the H.sub.2 flow at 60 L/h Under these conditions, stabilize the conditions for 8 h. 15.Perform 4 balances of 8 h each under the following conditions: Temperature at 355? C. Pressure at 54 kg/cm.sup.2 Flow of CIII at 120 mL/h Flow of H.sub.2 at 45.3 L/h 16.At the end of the 4 balances, recover 750 mL of product and wash it with a NaOH solution at 10 wt. % with a volume ratio of 1:1 for 30 min. Recover the washed and non-washed product. Label the samples (4 balances).
The average activity of the deep HDS of the CII feedstock considering 4 balances is in the order of 4.5 wppm of sulfur. 17.After finishing the last 4 balances, continue feeding the CIII feedstock at 120 mL/h under the same pressure and H.sub.2 flow conditions and increase the reactor temperature to 365? C. at a heating rate of 5? C./h. stabilize these conditions for 8 h and perform 4 balances under these conditions. 18.At the end of the 4 balances, recover 750 mL of product and wash it with a NaOH solution at 10 wt. % with a volume ratio of 1:1 for 30 min. Recover the washed and non-washed product. Label the samples (4 balances).
The average activity of the deep HDS of the CII feedstock considering 4 balances is in the order of 3.2 wppm of sulfur.

Example 4

(20) 1.Load 75 mL of CATI(HM) catalyst and 75 mL of inert A, compacting uniformly as indicated in the reactor diagram (see Figure) with the location of the catalytic bed and location and amount of inert A. 2.Adjust the operating pressure at 54 kg/cm.sup.2 with H.sub.2 flow rate of 75 L/h. Start heating up to 120? C. at a heating rate of 20? C./h; once these conditions are reached, they are kept for 2 h. 3.Increase the reactor temperature to 230? C. at a heating rate of 20? C./h. Start adding Kero/TGA at 180 mL/h (density at 20? C.=0.8292 g/mL), keeping the pressure at 54 kg/cm.sup.2 and adjusting the H.sub.2 flow rate at 75 L/h. 4.Stop the Kero/TGA blend. At 230? C., feed 180 mL/h of Kero/DMDS (density at 20? C.=0.8292 g/mL), keeping the pressure at 54 kg/cm.sup.2 and H.sub.2 flow rate at 67.9 L/h. Keep the conditions for 2 h. 5.During the last hour of the 2 h period, recover the sulfhydration product sample and establish the sulfur content. Likewise, recover the outlet gas sample and establish H.sub.2S content. Label the samples. 6.Increase the reactor temperature to 250? C. at a heating rate of 20? C./h, pressure at 54 kg/cm.sup.2, H.sub.2 flow at 69.7 L/h and 180 mL/h of Kero/DMDS blend. Keep these conditions for 2 h. 7.During the last hour of the 2 h period, recover the sulfhydration product sample and establish the sulfur content. Likewise, recover the outlet gas sample and establish H.sub.2S content. Label the samples. 8.Increase the reactor temperature to 270? C. at a heating rate of 20? C./h, pressure of 54 kg/cm.sup.2, H.sub.2 flow rate of 67.9 L/h and Kero/DMDS flow rate of 180 mL/h, keeping these conditions for 2 h. 9.During the last hour of the 2 h period, recover the sulfhydration product sample and establish the sulfur content. Likewise, recover the outlet gas sample and establish H.sub.2S content. Label the samples. 10.Increase the reactor temperature to 290? C. at a heating rate of 20? C./h, pressure of 54 kg/cm.sup.2, H.sub.2 flow rate of 67.9 L/h and Kero/DMDS flow rate of 180 mL/h, keeping these conditions for 2 h. 11.During the last hour of the 2 h period, recover the sulfhydration product sample and establish the sulfur content. Likewise, recover the outlet gas sample and establish H.sub.2S content. Label the samples. 12.Increase the reactor temperature to 315? C. at a heating rate of 20? C./h, pressure of 54 kg/cm.sup.2, H.sub.2 flow rate of 67.9 L/h and Kero/DMDS flow rate of 180 mL/h, keeping these conditions for 2 h. 13.During the last hour of the 2 h period, recover the sulfhydration product sample and establish the sulfur content. Likewise, recover the outlet gas sample and establish H.sub.2S content. Label the samples. 14.Stop feeding the Kero/DMDS blend and feed 180 mL/h of kerosene (density at 20? C.=0.8240 g/mL) at 315? C., pressure of 54 kg/cm.sup.2 and 67.9 L/h of H.sub.2. Perform 6 balances of 8 h each. At the end of each balance, recover 750 mL of product and wash it with a NaOH solution at 10 wt. % with a volume ratio of 1:1 for 30 min. Recover the washed product and the remaining product. Label the samples (8 samples). 15.Increase the reactor temperature to 345? C. at a heating rate of 5? C./h, pressure at 54 kg/cm.sup.2, H.sub.2 flow at 67.97 L/h and 180 mL/h of feedstock to be stabilized (Kero) (p.e..sub.20/4? C.=0.8240). 16.Catalytic evaluation: stop feeding the feedstock to be stabilized (Kero) and feed the CIV process feedstock as follows: Feed 120 mL/h of CIV (density at 20? C.=0.8203 g/mL), (LHSV=1.6 h.sup.?1) Increase the reactor temperature to 355? C. at a heating rate of 5? C./h Keep pressure at 54 kg/cm.sup.2 Adjust the H.sub.2 flow at 60 L/h Under these conditions, stabilize for 8 h 17.Perform 4 balances of 8 h each 18.At the end of the 4 balances, recover 750 mL of product and wash it with a NaOH solution at 10 wt. % with a volume ratio of 1:1 for 30 min. Recover the washed and non-washed product. Label the samples (4 balances).
The average activity of the deep HDS of the CII feedstock considering 4 balances is in the order of 4.3 wppm of sulfur. 19.At the end of the 4 last balances, continue feeding the feedstock CIV and perform the following changes: Feed 120 mL/h of CI (density at 20? C.=0.8203 g/mL), (LHSV 1.6 h.sup.?1) Increase the reactor temperature to 365? C. at a heating rate of 5? C./h Keep the pressure at 54 kg/cm.sup.2 Adjust the H.sub.2 flow at 60 L/h Under these conditions, stabilize for 8 h. 20.Carry out 4 balances of 8 h each 21.At the end of the 4 balances, recover 750 mL of product and wash it with a NaOH solution at 10 wt. % with a volume ratio of 1:1 for 30 min. Recover the washed and non-washed product. Label the samples (4 balances).
The average activity of the deep HDS of the CII feedstock considering 4 balances is in the order of 1.1 wppm of sulfur.