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EP-4558588-B1 - HYDROTREATMENT PROCESS USING A SEQUENCE OF CATALYSTS WITH A CATALYST BASED ON NICKEL AND TUNGSTEN ON A SILICA-ALUMINA SUPPORT

EP4558588B1EP 4558588 B1EP4558588 B1EP 4558588B1EP-4558588-B1

Inventors

  • CORRE, Thibaut
  • BERTRAND DRIRA, Chloe
  • GAY, Anne-Sophie
  • MERDRIGNAC, Isabelle

Dates

Publication Date
20260513
Application Date
20230628

Claims (11)

  1. Process for the hydrotreating of a hydrocarbon feedstock, at least 50% by weight of the compounds of which exhibit an initial boiling point of greater than 300°C and a final boiling point of less than 650°C, at a temperature of between 180°C and 450°C, a pressure of between 0.5 and 30 MPa, an hourly space velocity of between 0.1 and 20 h -1 and a hydrogen/feedstock ratio, expressed as volume of hydrogen, measured under standard temperature and pressure conditions, per volume of liquid feedstock, of between 50 l/l and 5000 l/l, so as to obtain a hydrotreated effluent, said process comprising the following stages: a) a first hydrotreating stage carried out in a first hydrotreating reaction section, employing at least one catalytic bed comprising at least one first hydrotreating catalyst, said hydrotreating reaction section being fed with at least said hydrocarbon feedstock and a hydrogen-comprising gas stream, said first catalyst comprising an alumina support, an active phase consisting of nickel and of molybdenum, and phosphorus and optionally an oxygen- and/or nitrogen- and/or sulfur-containing organic compound, and in which the first catalyst has a molybdenum content of between 5% and 40% by weight, expressed as MoO 3 , with respect to the total weight of the catalyst, a nickel content of between 1% and 10% by weight, expressed as NiO, with respect to the total weight of the catalyst, and a phosphorus content of between 0.1% and 20% by weight, expressed as P 2 O 5 , with respect to the total weight of the catalyst, b) a second hydrotreating stage carried out in a second hydrotreating reaction section, employing at least one catalytic bed comprising at least one second hydrotreating catalyst, said hydrotreating reaction section being fed with at least a part of the effluent obtained in stage a), said second catalyst comprising a silica-alumina support, an active phase consisting of nickel and of tungsten, phosphorus, and an oxygen- and/or nitrogen- and/or sulfur-containing organic compound, and in which: - the content of nickel, expressed in the NiO form, is of between 1.3% and 4.3% by weight, with respect to the total weight of the catalyst, - the content of tungsten, expressed in the WO 3 form, is of between 17% and 31% by weight, with respect to the total weight of the catalyst, - the content of phosphorus, expressed in the P 2 O 5 form, is preferably of between 1.3% and 3.4% by weight, with respect to the total weight of the catalyst, - the Ni/W molar ratio is of between 0.18 and 0.45 mol/mol, - the P/W molar ratio is of between 0.18 and 0.45 mol/mol.
  2. Hydrotreating process according to Claim 1, in which said first hydrotreating reaction section containing the first catalyst occupies a volume V1 and said second hydrotreating reaction section containing the second catalyst occupies a volume V2, the distribution of the volumes V1/V2 being of between 50% vol/50% vol and 90% vol/10% vol respectively of said first and second hydrotreating reaction section.
  3. Hydrotreating process according to Claim 2, in which the distribution of the volumes V1/V2 is of between 70% vol/30% vol and 80% vol/20% vol respectively of said first and second hydrotreating reaction section.
  4. Hydrotreating process according to one of the preceding claims, in which the silica content in the support of the second catalyst is of between 10% and 50% by weight, with respect to the total weight of the support.
  5. Hydrotreating process according to one of the preceding claims, in which the first catalyst additionally contains an oxygen- and/or nitrogen- and/or sulfur-containing organic compound.
  6. Hydrotreating process according to one of the preceding claims, in which the organic compound is chosen from a compound comprising one or more chemical functions chosen from a carboxyl, alcohol, thiol, thioether, sulfone, sulfoxide, ether, aldehyde, ketone, ester, carbonate, amine, nitrile, imide, oxime, urea or amide function or also compounds including a furan ring or also a sugar.
  7. Hydrotreating process according to Claim 6, in which the organic compound is chosen from γ-valerolactone, 2-acetylbutyrolactone, triethylene glycol, diethylene glycol, ethylene glycol, ethylenediaminetetraacetic acid (EDTA), maleic acid, malonic acid, citric acid, acetic acid, oxalic acid, gluconic acid, glucose, fructose, sucrose, sorbitol, xylitol, γ-ketovaleric acid, a di(C 1 -C 4 alkyl) succinate and more particularly dimethyl succinate, dimethylformamide, 1-methyl-2-pyrrolidinone, propylene carbonate, 2-methoxyethyl 3-oxobutanoate, bicine, tricine, 2-furaldehyde (also known under the name furfural), 5-hydroxymethylfurfural, 2-acetylfuran, 5-methyl-2-furaldehyde, ascorbic acid, butyl lactate, ethyl lactate, butyl butyryllactate, ethyl 3-hydroxybutanoate, ethyl 3-ethoxypropanoate, 2-ethoxyethyl acetate, 2-butoxyethyl acetate, 2-hydroxyethyl acrylate, 1-vinyl-2-pyrrolidinone, 1,3-dimethyl-2-imidazolidinone, 1,5-pentanediol, 1-(2-hydroxyethyl)-2-pyrrolidinone, 1-(2-hydroxyethyl)-2,5-pyrrolidinedione, 5-methyl-2(3H)-furanone, 1-methyl-2-piperidinone, 4-aminobutanoic acid, butyl glycolate, ethyl 2-mercaptopropanoate, ethyl 4-oxopentanoate, diethyl maleate, dimethyl maleate, dimethyl fumarate, diethyl fumarate, dimethyl adipate and dimethyl 3-oxoglutarate.
  8. Hydrotreating process according to one of Claims 5 to 7, in which the content of organic compound is of between 1% and 30% by weight, with respect to the total weight of the catalyst.
  9. Hydrotreating process according to one of the preceding claims, in which the first and/or the second catalyst is at least partially sulfur-based.
  10. Hydrotreating process according to one of the preceding claims, which is carried out as pretreatment in a fluidized bed catalytic cracking process.
  11. Hydrotreating process according to one of the preceding claims, which is carried out as pretreatment in a hydrocracking process.

Description

technical field The invention relates to a hydrotreating process for a hydrocarbon feedstock using a sequence of at least two specific catalysts. The objective of the process is the production of hydrodesulfurized, hydrodeazurized, and hydrodearomatized hydrocarbon feedstocks. Conventional hydrotreating catalysts typically comprise an oxide support and an active phase based on group VIB and VIII metals in their oxide forms, along with phosphorus. The preparation of these catalysts generally involves impregnating the support with the metals and phosphorus, followed by drying and calcination to obtain the active phase in its oxide forms. Before use in a hydrotreating and/or hydrocracking reaction, these catalysts are usually subjected to sulfidation to form the active species. The addition of an organic compound to hydrotreating catalysts to improve their activity has been recommended by those skilled in the art, particularly for catalysts prepared by impregnation followed by drying without subsequent calcination. These catalysts are often referred to as "additized dried catalysts". Usually, a hydrotreating catalyst for hydrocarbon cuts aims to eliminate the sulfur, nitrogen or aromatic compounds contained in them in order to bring, for example, a petroleum product to the required specifications (sulfur content, aromatic content etc...) for a given application (motor fuel, gasoline or diesel, domestic fuel oil, jet fuel). Due to stricter air quality legislation in many countries, ongoing efforts are underway to develop more efficient catalysts and processes for the production of ultra-low sulfur fuels. While significant progress has been made Although progress has been made in developing efficient catalysts for these processes, major challenges remain, for example, their modest activity in saturating aromatic hydrocarbons or in hydrodeazotation. Reducing sulfur, nitrogen, and aromatic content is therefore a desired outcome in the pretreatment stage for hydrocracking or fluidized bed catalytic cracking (FCC) processes to improve performance in subsequent hydrocracking or FCC stages. These processes typically handle feedstocks with high sulfur, nitrogen, and aromatic content. However, a hydrotreating catalyst optimized for hydrodesulfurization (HDS) is not automatically optimized for aromatic saturation (or hydrodearomatization HDA) or for hydrodeazotation (HDN), and vice versa. Therefore, catalyst sequences are often used, in which each catalyst is optimized for a specific type of hydrotreating process. Such supported catalyst sequences are described, for example, in the documents US2011/0079542 , US5068025 , CN1176290 , FR3013720 Or FR3013721 . There are also chains of unsupported catalysts, also called "bulk" catalysts according to Anglo-Saxon terminology, and known for example from documents US7816299 Or CN102851070 The chain of supported catalysts, however, has the advantage of using regenerable catalysts which are also less expensive (because they are less loaded with metals) and which are also active with a lower metal content. The document US2003/0116473 This document discloses a hydrotreating process using a sequence of a molybdenum-based supported catalyst followed by a tungsten-based supported catalyst. It does not disclose the volumetric distribution of the two catalytic zones. The document CN105435824 discloses a hydrotreating process using a sequence of a citric acid-additized CoMoP supported catalyst followed by a NiMoWP supported catalyst. The volume of the first catalyst is between 5 and 95%, and the volume of the second catalyst is between 95 and 5%. An increase in HDS and HDN is observed. Regardless of the catalyst sequence chosen, the resulting modifications do not always sufficiently increase the performance of the catalytic system to meet the specifications regarding the sulfur, nitrogen, and/or aromatic content of fuels. Consequently, it is essential for refiners to find new hydrotreating processes with improved performance in terms of activity and stability. The applicant has developed a hydrotreating process for a hydrocarbon feedstock comprising bringing said feedstock into contact with a specific sequence of catalysts to increase the overall activity and overall stability of the process. Summary The invention relates to a hydrotreating process for a hydrocarbon feedstock as described in the attached claims. The applicant has surprisingly discovered that a sequence of a first hydrotreating reaction section containing a first catalyst based on an active phase consisting of nickel and molybdenum on an alumina support and a second hydrotreating reaction section containing a second catalyst based on an active phase consisting of nickel and tungsten on a more acidic support in the presence of phosphorus and an organic compound presents a synergistic effect in terms of activity and stability in hydrotreating, particularly in aromatic hydrogenation (HDA) but also in hydrodeazotation (HDN) an