Process for preparing a mesopores-containing catalyst, catalyst thus obtained and use thereof in a hydroconversion process

Abstract

The invention relates to a process for preparing a hydroconverzation catalyst consisting of a modified zeolite Y, comprising the steps of a treatment of a modified zeolite Y by suspension thereof in a basic pH solution, stopping the previous treatment by neutralization of the modified zeolite Y containing solution with an acid-containing solution; filtering and washing the recovered modified zeolite Y solid, drying and optionally calcining the modified zeolite Y solid, placing the modified zeolite Y solid of step d) in contact, with stirring, in an ion exchange solution and optional steaming and/or calcining the modified zeolite Y type compound for obtaining the catalyst containing a modified zeolite Y.

Claims

1. A process for preparing a hydroconversion catalyst consisting essentially of a modified zeolite Y, comprising the steps of: a) treatment of a zeolite Y by suspension thereof in a basic pH solution, b) stopping the treatment of step a) by neutralization of the zeolite Y containing solution with an acid-containing solution consisting essentially of acetic acid, c) filtering and washing the recovered modified zeolite Y solid, d) drying and optionally calcining the modified zeolite Y solid, e) placing the modified zeolite Y solid of step d) in contact, with stirring, in an ion exchange solution, f) optionally steaming the modified zeolite Y type compound, g) calcining the modified zeolite Y type compound optionally steamed, this modified zeolite being a part of the composition of a final catalyst.

2. The process according to claim 1, wherein the base concentration of the solution of step a) may range from 0.001 to 2 M, preferably from 0.005 to 1, more preferably from 0.01 to 0.5, or may even be about 0.05 M.

3. The process according to claim 1, wherein, in step a), the basic pH solution/zeolite Y weight ratio is in the range of 20 to 100.

4. The process according to claim 1, wherein the concentration of the acid solution is ranging from 0.001 to 2 M.

5. The process according to claim 1, wherein the washing step c) is carried out with a solvent.

6. The process according to claim 1, wherein the calcination step of step d) is performed at a temperature of greater than or equal to 400 C.

7. The process according to claim 1, wherein, in step e), the modified zeolite Y is in contact with an ion exchange aqueous solution including ammonium ions at a concentration ranging from 0.01 to 0.5 M.

8. The process according to claim 1, wherein, after step e), a washing step is performed using a solvent.

9. The process according to claim 1, wherein the base concentration of the solution of step a) may range from 0.005 to 1.

10. The process according to claim 1, wherein the base concentration of the solution of step a) may range from 0.01 to 0.5.

11. The process according to claim 1, wherein, in step a), the basic pH solution/zeolite Y weight ratio is in the range of 30 to 80.

12. The process according to claim 1, wherein, in step a), the basic pH solution/zeolite Y weight ratio is in the range of 40 to 60.

13. The process according to claim 5, wherein the solvent is a polar solvent.

14. The process according to claim 8, wherein the solvent is a polar solvent.

15. The process according to claim 1, wherein the final catalyst also contains at least one metal selected from groups VIII and/or VIB.

Description

(1) The invention is now described with reference to the attached non-limiting drawings, in which:

(2) FIG. 1 represents the X-ray diffractograms of the parent zeolite Y (CBV760Zeolyst Int.), of the modified zeolite Y neutralized with H.sub.2SO.sub.4 (HYA-H2SO4), neutralized with H.sub.3PO.sub.4 (HYA-H3PO4), neutralized with acetic acid (HYA-acetic) and neutralized with citric acid (HYA-citric).

(3) FIG. 2 shows the pore size distribution for the parent zeolite Y (CBV760Zeolyst Int.), of the modified zeolite Y neutralized with H.sub.2SO.sub.4 (HYA-H2SO4), neutralized with H.sub.3PO.sub.4 (HYA-H3PO4), neutralized with acetic acid (HYA-acetic) and neutralized with citric acid (HYA-citric).

EXAMPLES

(4) The parent zeolite Y (CBV760, Zeolyst Int.) is referred to as HY30. The characteristics of HY30 are given in Table 1 and graphically represented in FIGS. 1 and 2.

Example 1: Preparation of a Modified Zeolite Y Catalyst Neutralized with H2SO4 (HYA-H2SO4)

(5) The compound HY30 is subjected to the following alkaline treatment: HY30 (20 g) is placed in contact with an aqueous 0.05 M NaOH solution (250 ml) for 15 minutes at room temperature and under stirring, after 15 minutes, a solution of 1M H.sub.2SO.sub.4 is added to the suspension during 5-10 minutes to reach a pH of 7, the resulting product is filtered off and washed with water, the filtered product is dried overnight at 80 C., aqueous 0.20 M NH.sub.4NO.sub.3 solution (250 ml) is added to the dry product, and the whole is left for 5 hours at room temperature under stirring. This manipulation is performed trice, the product obtained is washed with water, the product is then calcined at 500 C. for 4 hours (temperature gradient of 1 C./minute) in a stream of air, and then the HYA-H2SO4 is recovered.

(6) The characteristics of the samples are given in Table 1, graphically represented in FIGS. 1 and 2 and discussed in Example 5.

Example 2: Preparation of Modified Zeolite Y Catalyst Neutralized with H3PO4 (HYA-H3PO4)

(7) The compound HY30 is subjected to the following alkaline treatment: HY30 (20 g) is placed in contact with an aqueous 0.05 M NaOH solution (250 ml) for 15 minutes at room temperature and under stirring, after 15 minutes, a solution of 1M H.sub.3PO.sub.4 is added to the suspension during 5-10 minutes to reach a pH of 7, the resulting product is filtered off and washed with water, the filtered product is dried overnight at 80 C., aqueous 0.20 M NH.sub.4NO.sub.3 solution (250 ml) is added to the dry product, and the whole is left for 5 hours at room temperature under stirring. This manipulation is performed trice, the product obtained is washed with water, the product is then calcined at 500 C. for 4 hours (temperature gradient of 1 C./minute) in a stream of air, and then the HYA-H3PO4 is recovered.

(8) The characteristics of the samples are given in Table 1, graphically represented in FIGS. 1 and 2 and discussed in Example 5.

Example 3: Preparation of a Modified Zeolite Y Catalyst Neutralized with Acetic Acid (HYA-Acetic)

(9) The compound HY30 is subjected to the following alkaline treatment: HY30 (20 g) is placed in contact with an aqueous 0.05 M NaOH solution (250 ml) for 15 minutes at room temperature and under stirring, after 15 minutes, a solution of 1M acetic acid is added to the suspension during 5-10 minutes to reach a pH of 7, the resulting product is filtered off and washed with water, the filtered product is dried overnight at 80 C., aqueous 0.20 M NH.sub.4NO.sub.3 solution (250 ml) is added to the dry product, and the whole is left for 5 hours at room temperature under stirring. This manipulation is performed trice, the product obtained is washed with water, the product is then calcined at 500 C. for 4 hours (temperature gradient of 1 C./minute) in a stream of air, and then the HYA-acetic is recovered.

(10) The characteristics of the samples are given in Table 1, graphically represented in FIGS. 1 and 2 and discussed in Example 5.

Example 4: Preparation of a Modified Zeolite Y Catalyst Neutralized with Citric Acid (HYA-Citric)

(11) The compound HY30 is subjected to the following alkaline treatment: HY30 (20 g) is placed in contact with an aqueous 0.05 M NaOH solution (250 ml) for 15 minutes at room temperature and under stirring, after 15 minutes, a solution of 1M citric acid is added to the suspension during 5-10 minutes to reach a pH of 7 the resulting product is filtered off and washed with water, the filtered product is dried overnight at 80 C., aqueous 0.20 M NH.sub.4NO.sub.3 solution (250 ml) is added to the dry product, and the whole is left for 5 hours at room temperature under stirring. This manipulation is performed trice. the product obtained is washed with water, the product is then calcined at 500 C. for 4 hours (temperature gradient of 1 C./minute) in a stream of air, and then the HYA-citric is recovered.

(12) The characteristics of the samples are given in Table 1, graphically represented in FIGS. 1 and 2 and discussed in Example 5.

Example 5: Characterization of the Compounds HY30, HYA-H2SO4, HYA-H3PO4, HYA-Acetic and HYA-Citric

(13) X-Ray Diffraction

(14) FIG. 1 shows the X-ray diffractograms of the parent zeolite Y (CBV760) (HY30), of the modified zeolite Y catalyst neutralized with H.sub.2SO.sub.4 (HYA-H2SO4), neutralized with H.sub.3PO.sub.4 (HYA-H3PO4), neutralized with acetic acid (HYA-acetic) and neutralized with citric acid (HYA-citric). All diffractograms are corresponding to zeolite Y (faujasite structure). The crystallinity of the samples is decreasing in the order: HY30>HYA-citricHYA-H3PO4HYA-H2SO4>HYA-acetic (Table 1).

(15) Nitrogen Sorption

(16) Table 1 gives the BET surface area, the external surface area, the total, the microporous and the mesoporous pore volumes of the parent zeolite Y (CBV760) (HY30), of the modified zeolite Y catalyst neutralized with H.sub.2SO.sub.4 (HYA-H2SO4), neutralized with H.sub.3PO.sub.4 (HYA-H3PO4), neutralized with acetic acid (HYA-acetic) and neutralized with citric acid (HYA-citric). The surface area is smaller for the NaOH-treated samples, whereas it is higher for HYA-citric and HYA-H3PO4 than for HYA-H2SO4 and HYA-acetic. The external surface area is correspondingly higher for the mesoporized samples. The microporous volume decreases after the NaOH-treatment. HYA-H3PO4 and HYA-citric possess the highest microporous volumes among HYA samples. The mesoporous volume is increasing due to the NaOH-treatment.

(17) FIG. 2 shows the pores size distribution of all samples. HY30 shows only one broad peak at around 19 nm. The peaks at around 4 nm are an analytical anomaly. The NaOH-treated and neutralized HYA samples have an additional peak at around 2.8 nm, corresponding to small mesopores.

(18) Temperature-Programmed Desorption of Ammonia (TPD-NH.sub.3)

(19) Table 1 shows the overall acidity of the parent zeolite Y CBV760 (HY30), of the mesoporized zeolite neutralized with H.sub.2SO.sub.4 (HYA-H2SO4), neutralized with H.sub.3PO.sub.4 (HYA-H3PO4), neutralized with acetic acid (HYA-acetic) and neutralized with citric acid (HYA-citric) respectively. It is lower for HYA samples. Among HYA samples, HYA-H3PO4 and HYA-citric possess the highest overall acidity. This correlates with the microporous volume.

CONCLUSION

(20) Table 1 summarizes the most important characteristics of all samples. All samples possess a faujasite structure, however, the crystallinity of the HYA samples is lower than that of the parent HY30. During the NaOH-treatment, the surface area is decreasing as well as the microporous volume, whereas the mesoporous volume and especially the volume of small mesopores (2-8 nm) is increasing. The overall acidity correlates with the microporous volume.

(21) Within the HYA samples, HYA-H3PO4 and HYA-citric maintain the highest surface area, microporous volume and overall acidity still showing considerable amount of mesopores. This might be explained by their lower acidity and the polyprotic nature.

(22) TABLE-US-00001 TABLE 1 Summary of the characterization results of HY30, HYA-H2SO4, HYA-H3PO4, HYA-acetic and HYA-citric HYA- HYA- HYA- HYA- Sample HY30 H2SO4 H3PO4 acetic citric Crystallinity % 95 68 70 55 71 Si/Al bulk 24.3 30.1 29.4 n.d. .sup.a n.d. .sup.a S.sub.BET.sup.b m.sup.2/g 938 765 797 685 816 S.sub.ext.sup.c m.sup.2/g 107 287 236 379 245 V.sub.tot.sup.d ml/g 0.549 0.533 0.533 0.426 0.546 V.sub.micr.sup.e ml/g 0.339 0.199 0.235 0.128 0.24 V.sub.meso.sup.f ml/g 0.21 0.30 0.28 0.34 0.28 TPD-NH.sub.3 mmol/g 0.47 0.39 0.45 0.39 0.43 .sup.a not determined; .sup.bBET surface area; .sup.cexternal surface area; .sup.dtotal pore volume; .sup.emicroporous volume; .sup.fmesoporous volume.

Example 6: CatalysisHydrocracking of Squalane

(23) The samples HY30, HYA-H2SO4, HYA-H3PO4, HYA-acetic and HYA-citric containing 0.5 wt % Pt were catalytically tested in hydrocracking of squalane (Alfa Aesar, 98.8%). The tests were performed using plug-flow reactors at following operating conditions:

(24) H.sub.2 pressure: 20 barg

(25) Temperature: 180-300 C.

(26) WHSV: 3 h.sup.1

(27) H.sub.2/squalane ratio: 4 mol/mol.

(28) The tests were performed using 1 mL of catalyst (sieved to 120-160 m), activated at 450 C. (1 C./min) for 4 h in a flow of hydrogen.