FI114317B - Vätedecykliseringsförfarande - Google Patents

Description

114317 j 1

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

5 It is known that hydrocarbon oil products must meet certain chemical and physical requirements if they are to be used commercially. One of the requirements that gas oil must meet is the cetane number.

Paraffins are compounds that preferentially affect cetane number. Naphthenes are not as favorably affected by naphthenes, while aromatic compounds are even more undesirable in this respect. Several methods are known for raising the cetane number of a particular gas oil, such as hydrogen cracking and hydrogenation. The disadvantage of hydrocracking is that part of the feed becomes unwanted lighter products. Hydrogenation involves the conversion of olefinic compounds, particularly aromatic compounds, to the corresponding saturated compounds. In this way, the best 20 cetane numbers that can be achieved for a given gas oil without substantially cleaving the molecules are achieved.

It is also important from an environmental point of view to produce gas oil which is low in aromatic constituents.

It has now been found that a gas oil having a good se: 25 tane and a content of aromatic compounds is present. small, can be achieved in a commercially attractive manner by subjecting gas oil to a particular process to reduce the amount of ring-structured constituents it contains. Such a process optimizes the cetane number of the present compounds while preventing the hydrocarbon cracking of substantially hydrocarbons, which results in undesirable lighter products.

This invention relates to a process for reducing the amount of annular constituents present in gas oil. *: 35 comprising contacting gas oil with hydrogen at elevated temperature and pressure using 114317 2 catalysts containing one or more Group VIII noble metals on a support, wherein said carrier consists of a modified type Y zeolite having a starting size of 2,420 - 2,440 nm, wherein the molar ratio of SiO 2 to Al 2 O 3 is 10 to 150, and recovering the gas oil containing the reduced amount of ring constituents, said catalyst being substantially free of amorphous cracking compounds.

By gas oil is meant a hydrocarbon oil consisting of 10 hydrocarbons boiling in the range of 170 ° C to 390 ° C and containing at least 25% by weight of hydrocarbons boiling in the range of 250 ° C to 390 ° C and further having a Cetane number of 38 to 49 It is expedient to use a relatively light gas oil, i. an oil consisting predominantly of hydrocarbons boiling in the range of 170 ° C to 320 ° C. Hydrogen treated gas oils are preferably used because they contain relatively little nitrogen and sulfur, which favorably affects the life of the catalyst.

20 Hydrogen cyclization refers to the reduction of the number of ring-shaped constituents present in gas oil. The amount of annular constituents present in the feed is preferably reduced by at least 10%, more preferably by at least 15%. Nothing essential to cleavage. ,; 25, which means that the present invention * ·. The gas oil recovered from the process of the present invention contains at least 5% by weight of hydrocarbons boiling between the temperature at which 90% by weight of the supplied gas oil has boiled and the final boiling point of the supplied gas oil.

* ... · The process of this invention utilizes a catalyst containing one or more precious metals belonging to Group VIII. Suitable metals that may be present are platinum and / or palladium. The catalyst preferably contains from 0.05 to 3% by weight of precious metal or metals based on the amount of zeolite. More preferably, the 114317 3 catalyst contains platinum and palladium in a molar ratio of 0.25 to 0.75.

The catalyst further contains a carrier consisting of a modified zeolite of type Y having a molar ratio of 5 SiO 2 to A 2 Cl 2 of 10 to 150. It has been found that the catalysts having a relatively low molar ratio of SiCl 2 to A , produce surprisingly good results. A preferred molar ratio is from 15 to 50, and more particularly from 20 to 45. The type Y zeolite used has a primer size of 2.420 to 2.440 nm, most particularly 2.422 to 2.435 nm.

The hydrogen cyclization process can be carried out at a temperature of from 150 to 400 ° C, preferably from 250 to 380 ° C. The hydrogen partial pressure used is usually between 10 bar and 150 bar, preferably between 30 and 100 bar.

In the process of the present invention, the combination of catalyst, temperature and pressure is generally selected to provide a gas oil having a Cetane number higher than 45, preferably greater than 50, containing less than 25% by weight, preferably less than 20% by weight, of aromatic compounds. . It has been found that the process of the present invention can even produce gas oils having a cetane number greater than 50 and containing less than. 5% by weight of aromatic compounds, so-called. "green gas oil • f *, ···, ice". The cetane number is measured according to ASTM D97 6.

• · 25 The characteristics of the gas oil produced depend on the gas oil supplied and the process conditions. The cetane number * * / month and the concentration of aromatic constituents pursued in the commercial operation are determined on the basis of economic considerations.

The method according to the present invention is illustrated in more detail by the following example.

• * · • · * Example • 0 • »· * ... Hydrogen-treated straight-line oil, as described in Table 1, was contacted with a catalyst containing zeolite of type Y, with a primary cell size. was 2,424 nm and had a SiO 2 / Al 2 O 3 molar ratio of 114317440, as well as 0.3 wt% platinum and 0.5 wt% palladium, based on the amount of zeolite, at a hydrogen pressure of 35 bar and a flow rate catalyst at 265 ° C. at 1.4 t / m3.h.

The results obtained are shown in Table 2.

The amount of ring structure in the product was reduced by 18% relative to the amount of ring structure in the feed.

Table 1

Boiling point distribution (° C):

Initial Boiling Point 179 10% 205 30% 218 15 50% 233 70% 249 90% 272

Final boiling point

Cetane number 49.3 20 Aromatic content (vol%) 20.1:: Table 2, **: Boiling point distribution (° C): *>

Initial boiling point 180 25 10% 205 j 30% 218 50% 231 j! · 70% 247 90% 272 i I »· 30 End Boiling Point 293

Cetane number 53.4 • 1.it Concentration of aromatic constituents (% by volume) 3.9 · · · · · · ·

Claims (9)

114317 A process for reducing the amount of annular constituents in gas oil, characterized in that the gas oil is contacted with hydrogen at elevated temperature and pressure using a catalyst comprising one or more Group VIII noble metals in a carrier consisting of a modified type Y a zeolite having an elemental size of 2.420 to 10 2.440 nm and a SiO2 to Al2 O3 molar ratio of 10 to 150, and a gas oil containing a reduced amount of ring-structured components is recovered, said catalyst being substantially free of amorphous cracking compounds . Process according to claim 1, characterized in that the molar ratio of SiO 2 to Al 2 O 3 in the modified type Y zeolite is 15 to 50. Process according to Claim 2, characterized in that the molar ratio of SiO 2 to Al 2 O 3 in the transformed type Y zeolite is 20 to 45. Method according to any one of the preceding claims, characterized in that the size of the modified booth of type Y zeolite is between 2,422 and · · ·. '. 2.4 35 nm. * ». ·,: 25 The process of any one of the preceding claims • 1 ·! process according to that process, characterized in that the process is carried out at a temperature of 150 to 400 ° C. Process according to any one of the preceding claims, characterized in that the process 30 is carried out at a hydrogen partial pressure of 10 to 150 bar. The process according to any one of the preceding claims, characterized in that the catalyst, ·· 1. contains platinum and palladium in a molar ratio of 0.25 to 0.75. f 1 · • I t · 114377 A process according to any one of the preceding claims, characterized in that the gas oil to be recovered contains less than 25% by weight of aromatic compounds and has a Cetane number higher than 50. Process according to any one of the preceding claims, characterized in that the gas oil to be recovered contains less than 5% by weight of aromatic compounds and has a Cetane number higher than 50. * · • • • 1 · • «« • · *> · • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • •