JP3210729B2 - Method for reducing the amount of annular structures present in gas oil - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

This invention relates to a method for reducing the amount of annular structures present in gas oil.

[0002]

BACKGROUND OF THE INVENTION It is well known that hydrocarbon oil products must meet certain chemical and physical requirements if they are to be applied commercially. One of the requirements that gas oil must meet is the cetane index. The compound that preferably contributes to the cetane index is paraffin. The contribution of naphthenes to the cetane index is less preferred, while aromatics are less preferred in that respect. Several methods are known for increasing the cetane index of a given gas oil, such as hydrocracking and hydrogenation. Hydrocracking has the disadvantage that a portion of the feed is converted to undesirable lighter products. Hydrogenation consists in converting olefinic compounds, especially aromatics, to the corresponding saturated compounds. The optimal cetane index feasible for a given gas oil without substantial cracking of the molecule is
It would not be obtained in such a manner. Furthermore, it is important from an environmental point of view to produce gas oils with low aromatic content.

[0003]

By subjecting the gas oil to a particular method of reducing the amount of cyclic structures in the gas oil, a gas oil of good cetane index and low aromatics content is a commercially attractive way. It has now been found that In such a way, the cetane index of the compounds present is optimized, while the hydrocracking of hydrocarbons, which leads to the formation of undesired lighter products, is substantially prevented.

[0004]

The present invention is directed to a method for reducing the amount of annular structures present in gas oil, comprising a unit cell size between 24.20A and 24.40A and 10 and 15A.
Modified Y having a SiO ₂ / Al ₂ O ₃ molar ratio between 0 and 0
Contacting gas oil with hydrogen at elevated temperature and pressure using a catalyst comprising one or more Group VIII noble metals supported on a support comprising type zeolite; And recovering gas oil containing the same.

[0005] Gas oils contain predominantly hydrocarbons boiling in the range between 170 ° C and 390 ° C and contain at least 25% by weight of hydrocarbons boiling in the range between 250 ° C and 390 ° C. Moreover, it refers to a hydrocarbon oil having a cetane index between 38 and 49. Suitably, relatively light gas oils are used, i.e. gas oils mainly containing hydrocarbons boiling in the range between 170 ° C and 320 ° C. Preferably, hydrogenated gas oils are used, since they have a relatively low nitrogen and sulfur content, since these low contents favorably contribute to the life of the catalyst. is there. Hydrodecyclization is understood to result in a reduction in the amount of cyclic structures present in the gas oil. Preferably, the amount of cyclic structure present is reduced by at least 10%, more preferably at least 15%, based on the amount of cyclic structure present in the feed. Cracking does not occur substantially, which means that the gas oil recovered from the process according to the invention boils in the range between 90% by weight of the feed gas oil and the final boiling point of the feed gas oil. At least 5% by weight.

In the process according to the invention, a catalyst containing one or more noble Group VIII metals is used. Suitable metals that may be present are platinum and / or palladium.
Preferably, the catalyst comprises between 0.05% and 3% by weight of noble metal, based on the amount of zeolite. More preferably, the catalyst comprises a molar ratio of platinum and palladium between 0.25 and 0.75. The catalyst further comprises a support comprising a modified Y-type zeolite having a SiO ₂ / Al ₂ O ₃ molar ratio of between 10 and 150. Relatively low S
bring iO ₂ / Al ₂ O ₃ molar ratio good results enough catalyst surprising, it was found that. Preferred molar ratios are between 15 and 50, more particularly between 20 and 45. The unit cell size of the applied Y-type zeolite is 2
Between 4.20A and 24.40A, more particularly 24.22A
And 24.35A. The hydrodecyclization may suitably be performed at a temperature between 150 and 400 ° C, preferably between 250 and 380 ° C. The hydrogen partial pressure applied will usually be between 10 and 150 bar, preferably between 30 and 100 bar.

In the present process, the catalyst, temperature and pressure generally produce a gas oil having a cetane index greater than 45, preferably greater than 50, and containing less than 25% by weight, preferably less than 20% by weight, of an aromatic compound. Let's choose the combination that will be done. It has been found that even gas oils having a cetane index of greater than 50 and containing less than 5% by weight of aromatics, ie so-called "raw gas oils", can be produced in the process. The cetane index is measured according to ASTM D976. The properties of the gas oil produced will depend on the feed gas oil and the process conditions. The intended cetane index and aromatics content in commercial operations are determined by economic considerations.

[0008]

The method of the present invention is further illustrated by the following example. Example The hydrogenated straight-run gas oil described in Table 1 was converted to 24.24.
Consisting of a unit cell size of A and a SiO ₂ / Al ₂ O ₃ molar ratio of 40 and comprising a Y-type zeolite containing 0.3% by weight of platinum and 0.5% by weight of palladium, based on the amount of zeolite. The catalyst, a temperature of 265 ° C., a hydrogen partial pressure of 35 bar and 1.4 ton / m ³ . The contact was made at a weight hourly space velocity of hr. Table 2 shows the obtained results. The amount of cyclic structure present in the resulting product was reduced by 18% based on the amount of cyclic structure present in the feed.

[0009]

Table 1 Table 1 Boiling point distribution (° C) Initial boiling point 179 10% 205 30% 218 50% 233 70% 249 90% 272 Final boiling point 294 Cetane index 49.3 Aromatic content (% by volume) 20.1

[0010]

Table 2 Boiling point distribution (° C.) Initial boiling point 180 10% 205 30% 218 50% 231 70% 247 90% 272 Final boiling point 293 Cetane index 53.4 Aromatic content (% by volume) 3.9

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Jacques Lucien, Netherlands 2596 H.R.H.H., Karel Wan-Bilantran 30 (72) Inventor Geraldas Leonardas Bosco S.E.E.M.Netherlands 2596 H.E. Earl, Hague, Karel Wan-Billantran 30 (56) References JP-A-62-294443 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C10G 49/08 B01J 29 / 12 C10G 47/18

Claims (9)

(57) [Claims] 1. A method for reducing the amount of cyclic structures present in a gas oil, comprising a unit cell size between 24.20 A and 24.40 A and a SiO 2 between 10 and 150.
One or more VIIIs supported on a support comprising a modified Y zeolite having a ₂ / Al ₂ O ₃ molar ratio
The gas oil is contacted with hydrogen at elevated temperature and pressure using a catalyst consisting of group noble metals and a reduced amount of annular structure , 90% by weight of the feed gas oil boiling point and the feed gas oil
Reduce the amount of hydrocarbons boiling between the final boiling point
Recovering a gas oil which also contains 5% by weight , and wherein the catalyst is essentially free of any amorphous pyrolysis components. 2. The method of claim 1, wherein the modified Y zeolite has a SiO ₂ / Al ₂ O ₃ molar ratio between 15 and 50. 3. The method of claim 2, wherein the modified Y zeolite has a SiO ₂ / Al ₂ O ₃ molar ratio between 20 and 45. 4. The modified Y zeolite has 24.22 A and 2
2. A unit cell size having a unit cell size of between 4.35A.
3. The method according to any one of items 1 to 3. 5. The method according to claim 1, which is carried out at a temperature between 150 ° C. and 400 ° C. 6. The process as claimed in claim 1, wherein the process is carried out at a partial pressure of hydrogen of between 10 and 150 bar. 7. The process according to claim 1, wherein the catalyst comprises platinum and palladium in a molar ratio between 0.25 and 0.75. 8. recovering a gas oil containing less than 25% by weight aromatics and having a cetane index greater than 50;
A method according to any one of claims 1 to 7. 9. The process according to claim 1, wherein a gas oil containing less than 5% by weight of aromatic compounds and having a cetane index greater than 50 is recovered.