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US-12624298-B2 - Entrained-bed hydroconversion of a heavy hydrocarbon feedstock, comprising pre-mixing said feedstock with an organic additive

US12624298B2US 12624298 B2US12624298 B2US 12624298B2US-12624298-B2

Abstract

The present invention relates to a slurry hydroconversion process of a heavy oil feedstock comprising: (a) preparing a first conditioned feedstock ( 103 ) by blending said heavy oil feedstock ( 101 ) with an organic chemical compound ( 102 ) comprising at least one carboxylic acid function and/or at least one ester function and/or an acid anhydride function; (b) preparing a second conditioned feedstock ( 105 ) by mixing a catalyst precursor composition ( 104 ) with said first conditioned feedstock so that a colloidal or molecular catalyst is formed when it reacts with sulfur; (c) heating the second conditioned feedstock in at least one preheating device; (d) introducing the heated second conditioned feedstock ( 106 ) into at least one slurry bed reactor and operating said slurry bed reactor in the presence of hydrogen and at hydroconversion conditions to produce an upgraded material ( 107 ), the colloidal or molecular catalyst being formed during step (c) and/or (d).

Inventors

  • Joao Marques
  • Thibaut CORRE
  • Jeremie BARBIER
  • Brett Matthew SILVERMAN
  • David M. Mountainland
  • Sukesh Parasher

Assignees

  • IFP Energies Nouvelles

Dates

Publication Date
20260512
Application Date
20220627
Priority Date
20210708

Claims (20)

  1. 1 . A process for the hydroconversion of a heavy oil feedstock ( 101 ) containing a fraction of at least 50% by weight having a boiling point of at least 300° C., and containing metals and asphaltenes, comprising: (a) preparing a first conditioned heavy oil feedstock ( 103 ) by blending said heavy oil feedstock ( 101 ) with an organic chemical compound ( 102 ) comprising at least one carboxylic acid function and/or at least one ester function and/or an acid anhydride function; (b) preparing a second conditioned heavy oil feedstock ( 105 ) by mixing a catalyst precursor composition ( 104 ) comprising molybdenum 2-ethylhexanoate, molybdenum naphthanate, vanadium naphthanate, vanadium octoate, molybdenum hexacarbonyl, vanadium hexacarbonyl, or iron pentacarbonyl with the first conditioned heavy oil feedstock ( 103 ) from (a) in a manner so that a colloidal or molecular catalyst is formed when it reacts with sulfur; (c) heating the second conditioned heavy oil feedstock from (b) in at least one preheating device; (d) introducing said heated second conditioned heavy oil feedstock ( 106 ) from (c) into at least one slurry bed reactor and operating said slurry bed reactor in the presence of hydrogen and at hydroconversion conditions to produce an upgraded material ( 107 ), and wherein the colloidal or molecular catalyst is formed in situ within the second conditioned heavy oil feedstock at (c) and/or at (d).
  2. 2 . A process as claimed in claim 1 , wherein (a) comprises mixing said organic chemical compound ( 102 ) and said heavy oil feedstock ( 101 ) in a dedicated vessel of an active mixing device.
  3. 3 . A process as claimed in claim 1 , wherein (a) comprises injecting said organic chemical compound ( 102 ) into a conduit conveying said heavy oil feedstock ( 101 ) toward the slurry bed reactor.
  4. 4 . A process as claimed in claim 1 , wherein (a) is carried out at a temperature between room temperature and 300° C., and the residence time of the organic chemical compound with the heavy oil feedstock before (b) is between 1 second and 10 hours.
  5. 5 . A process as claimed in claim 1 , wherein the organic chemical compound ( 102 ) is selected from 2-ethylhexanoic acid, naphthenic acid, caprylic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, and sebacic acid, ethyl octanoate, ethyl 2-ethylhexanoate, 2-ethylhexyl 2-ethylhexanoate, benzyl 2-ethylhexanoate, diethyl adipate, dimethyl adipate, bis(2-ethylhexyl) adipate, dimethyl pimelate, dimethyl suberate, monomethyl suberate, hexanoic anhydride, caprylic anhydride, and mixtures thereof.
  6. 6 . A process as claimed in claim 5 , wherein the organic chemical compound ( 102 ) comprises 2-ethylhexanoic acid.
  7. 7 . A process as claimed in claim 5 , wherein the organic chemical compound ( 102 ) comprises ethyl octanoate or 2-ethylhexyl 2-ethylhexanoate.
  8. 8 . A process as claimed in claim 1 , wherein the molar ratio between said organic chemical compound ( 102 ) added at a) and the active metal(s) of the catalyst precursor composition ( 104 ) added at (b) in said second conditioned heavy oil feedstock is between 0.1:1 and 20:1.
  9. 9 . A process as claimed in claim 1 , wherein the colloidal or molecular catalyst comprises molybdenum disulfide.
  10. 10 . A process as claimed in claim 1 , wherein (b) comprises: (b1) pre-mixing the catalyst precursor composition with a hydrocarbon oil diluent below a temperature at which a substantial part of the catalyst precursor composition begins to undergo thermal decomposition, to form a diluted precursor mixture; and (b2) mixing said diluted precursor mixture with the first conditioned heavy oil feedstock.
  11. 11 . A process as claimed in claim 10 , wherein (b1) is carried out at a temperature between room temperature and 300° C. and for a period of time from 1 second to 30 minutes, and (b2) is carried out at a temperature between room temperature and 300° C. and for a period of time from 1 second to 30 minutes.
  12. 12 . A process as claimed in claim 1 , wherein (c) comprises heating at a temperature between 280° C. and 450° C.
  13. 13 . A process as claimed in claim 1 , wherein the heavy oil feedstock ( 101 ) comprises at least one of the following feedstocks: heavy crude oil, oil sand bitumen, atmospheric tower bottoms, vacuum tower bottoms, resid, visbreaker bottoms, coal tar, heavy oil from oil shale, liquefied coal, heavy bio oils, and heavy oils comprising plastic waste and/or a plastic pyrolysis oil.
  14. 14 . A process as claimed in claim 1 , wherein the heavy oil feedstock ( 101 ) has a sulfur at a content of greater than 0.5% by weight, a Conradson carbon residue of at least 0.5% by weight, C 7 asphaltenes at a content of greater than 1% by weight, transition and/or post-transition and/or metalloid metals at a content of greater than 2 ppm by weight, and alkali and/or alkaline earth metals at a content of greater than 2 ppm by weight.
  15. 15 . A process as claimed in claim 1 , wherein hydroconversion (d) is carried out under an absolute pressure of between 2 MPa and 38 MPa, at a temperature of between 300° C. and 550° C., at an liquid hourly space velocity LHSV relative to the volume of each slurry bed reactor of between 0.05 h −1 and 10 h −1 and under an amount of hydrogen mixed with the feedstock entering slurry bed reactor of between 50 and 5000 normal cubic meters (Nm 3 ) per cubic meter (m 3 ) of feedstock.
  16. 16 . A process as claimed claim 1 , wherein the concentration of the catalyst metal in the second conditioned oil feedstock ( 105 ) is in a range of 10 ppm to 10000 ppm by weight of the heavy oil feedstock.
  17. 17 . A process as claimed in claim 1 , wherein (a) is carried out at a temperature between 70° C. and 200° C., and the residence time of the organic chemical compound with the heavy oil feedstock before (b) is between 1 second and 10 hours.
  18. 18 . A process as claimed in claim 1 , wherein (c) comprises heating at a temperature between 300° C. and 400° C.
  19. 19 . A process as claimed in claim 1 , wherein the catalyst precursor composition is molybdenum 2-ethylhexanoate.
  20. 20 . A process as claimed claim 16 , wherein the catalyst metal is molybdenum.

Description

TECHNICAL FIELD The present invention relates to a process for converting heavy oil feedstocks in the presence of hydrogen, a colloidal or molecular catalyst, and an organic additive. In particular, the present invention relates to a process for hydroconversion of heavy oil feedstocks containing a fraction of at least 50% by weight having a boiling point of at least 300° C., and especially heavy oil feedstocks including a significant quantity of asphaltenes and/or fractions boiling above 500° C., such as crude oils or heavy hydrocarbon fractions resulting from the atmospheric and/or vacuum distillation of a crude oil, to yield lower boiling, higher quality materials. The process specifically comprises premixing said feedstock with an organic additive, before being brought into contact with the catalyst, said catalyst operating in one or several slurry bed reactors, in order to allow upgrading of this low-quality feedstock while minimizing fouling in equipment prior to hydroconversion in the slurry bed reactor(s). PRIOR ART Converting heavy oil feedstocks into useful end products requires extensive processing, including reducing the boiling point of the heavy oil, increasing the hydrogen-to-carbon ratio, and removing impurities such as metals, sulfur, nitrogen and high carbon forming compounds. Catalytic hydroconversion is commonly used for heavy oil feedstocks and is generally carried out using three-phase reactors in which the feedstock is brought into contact with hydrogen and a catalyst. In the reactor, the catalyst can be used in the form of a fixed bed, a moving bed, an ebullated bed or an entrained bed, as for example described in chapter 18 “Catalytic Hydrotreatment and Hydroconversion: Fixed Bed, Moving Bed, Ebullated Bed and Entrained Bed” of the book “Heavy Crude Oils: From Geology to Upgrading, An Overview”, published by Éditions Technip in 2011. In the case of an ebullated bed or an entrained bed, the reactor comprises an upflow of liquid and of gas. The choice of the technology generally depends on the nature of the feedstock to process, and in particular its metal content, its tolerance for impurities and the conversion targeted. Slurry bed hydroconversion processes use entrained bed technologies, also known as slurry bed technologies. In such processes, a dispersed catalyst or catalyst precursor is injected on a continuous basis within the heavy oil feedstock in the slurry reactor, promoting hydrogenation of radicals formed by thermal cracking reactions, and limiting coke formation. The catalyst provides not only the catalytic activity but also a surface for the deposition of metals and asphaltenes from the feedstock. The catalyst of very small size, dispersed within the feedstock, is entrained out of the reactor with the effluents, since the catalyst and liquid heavy oil feedstock ac t like one homogeneous phase. Slurry bed hydroconversion processes are known to generally aim at fully converting heavy oil feedstock into lighter fractions, using highly severe operating conditions (temperature, hydrogen partial pressure, residence time). Theoretical advantages of slurry bed processes reside in a much better hydrogenation, especially of the heaviest products, thanks to a better accessibility of the active sites, resulting in a higher conversion, improved product quality and higher product stability. Moreover, owing to the lower catalyst residence time, deactivation of the catalyst is greatly reduced. Regarding the stability of the products, it is known that during operation of slurry bed reactor for upgrading heavy oil, the heavy oil is heated to a temperature at which the high boiling fractions of the heavy oil feedstock typically having a high molecular weight and/or low hydrogen/carbon ratio, an example of which is a class of complex compounds collectively referred to as “asphaltenes”, tend to undergo thermal cracking to form free radicals of reduced chain length. These free radicals have the potential of reacting with other free radicals, or with other molecules, to produce coke precursors and sediments. A slurry catalyst passing through the reactor reacts with the free radicals in these zones, forming stable molecules of reduced molecular weight and boiling point, and thus contributes to control and reduce the formation of sediments and coke precursors. As formation of coke and sediments is a major cause of hydroconversion equipment fouling, such a slurry process allows preventing the fouling of downstream equipment, such as separation vessels, distillation columns, heat exchangers etc. Slurry catalysts for heavy oil hydroconversion, and in particular colloidal or molecular catalysts formed by the use of soluble catalytic precursors, are well known in the art. It is known in particular that certain metal compounds, such as organosoluble compounds (e.g. molybdenum naphthenate or molybdenum octoate as cited in U.S. Pat. No. 4,244,839, US2005/0241991, US2014/0027344) or water-soluble compound