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CA-3066487-C - CATALYTIC SYSTEM, AND PROCESS FOR REMOVING HETEROATOMIC COMPOUNDS FROM HYDROCARBON STREAMS

CA3066487CCA 3066487 CCA3066487 CCA 3066487CCA-3066487-C

Abstract

The present invention describes an extractive oxidation process for removing contaminants from hydrocarbon streams using an ionic liquid combined with an organometallic ionic complex of iron(II), which comprises a complex of iron(II) cation with an ionophilic binder, catalyst of iron(II) with ionophilic binder in its molecular structure, oxidation of which is performed with an oxidizing agent and is catalysed by the organometallic iron(II) complex present in the phase of the ionic liquid. Besides maintaining its characteristics of selective solvent of oxidizing compounds, the ionic liquid combined with the organometallic complex of iron(II) with catalytic ionophilic binder of the oxidizing agent, stimulating the reactive phenomenon taking place in the ionic liquid phase, with the effect that the iron remains stable in the ionic liquid phase, without being leached into the oily phase. This measure results in a considerable improvement in removal of the heteroatoms from the hydrocarbon medium.

Inventors

  • Wladmir Ferraz De Souza
  • JANICE ADAMSKI
  • Jairton Dupont

Assignees

  • PETROLEO BRASILEIRO S.A. - PETROBRAS
  • UNIVERSIDADE FEDERAL DO RIO GRANDE DO SUL - UFRGS

Dates

Publication Date
20260505
Application Date
20180608
Priority Date
20170609

Claims (14)

  1. 14 CLAIMS 1. Catalytic system for removing heteroatomic compounds from hydrocarbon streams, characterized in that the catalytic system comprises an ionic liquid with 1,3-dialkylimidazolium cation, an anion and an organometallic complex of iron(II), in which the organometallic complex of iron(II) is an ionic system that consists of an organometallic cation of iron(II) with an ionophilic binder system and an anion.
  2. 2. Catalytic system according to claim 1, characterized in that the 1,3-dialkylimidazolium is based on the compound 1-n-butyl-3-methylimidazolium.
  3. 3. Catalytic system according to claim 1, characterized in that the anion is selected from tetrafluoroborate, hexafluorophosphate and bis-trifluoromethanesulphonimidate.
  4. 4. Catalytic system according to claim 1, characterized in that the organometallic complex of iron(II) is prepared from an iron(II) salt and an ionophilic binder precursor.
  5. 5. Catalytic system according to any one of claims 1 and 4, characterized in that the organometallic complex of iron(II) is prepared from an iron(II) bromide salt and 4-((2,3-dimethyl;-imidazol-1-yl)methyl)- 4’-methyl-2,2’-bipyridine.
  6. 6. Extractive oxidation process for removing heteroatoms from hydrocarbon streams, characterized in that the extractive oxidation process comprises the steps of: a) providing a hydrocarbon stream of mineral or synthetic origin containing heteroatomic compounds to form phase I; b) providing a catalytic system according to any one of claims 1 to 5 and adding an oxidizing agent to form phase II; c) promoting contact between phases I and II so that the reactions of oxidation of the heteroatomic compounds take place; and d) separating phase I, which comprises the hydrocarbon phase, from phase II, which comprises the phase of the ionic liquid combined with the organoferrous complex, where the oxidized heteroatomic compounds arising from the hydrocarbon stream are present.
  7. 7. Process according to claim 6, characterized in that the oxidizing agent is a peroxide.
  8. 8. Process according to claim 7, characterized in that the oxidizing agent is at least one inorganic peroxide.
  9. 9. Process according to claim 7, characterized in that the oxidizing agent is hydrogen peroxide.
  10. 10. Process according to claim 7, characterized in that the oxidizing agent is at least one organic peroxide.
  11. 11. Process according to claim 7, characterized in that the oxidizing agent is a mixture of at least one organic peroxide and at least one inorganic peroxide, in any proportions.
  12. 12. Process according to claim 6 or 7, characterized in that the heteroatomic compounds comprise sulphur-containing and/or nitrogen-containing compounds.
  13. 13. Process according to any one of claims 6 to 8, characterized in that the oxidation reaction is carried out at a temperature varying from 50 to 150oC.
  14. 14. Process according to any one of claims 6 to 8, characterized in that the oxidation reaction is carried out for periods of from 5 to 250 minutes.

Description

1 CATALYTIC SYSTEM, AND PROCESS FOR REMOVING HETEROATOMIC COMPOUNDS FROM HYDROCARBON STREAMS CROSS-REFERENCE TO RELATED APPLICATION [001] This application claims the benefit of priority to BR 10 2017 012318-8, filed 9 June 2017 FIELD OF THE INVENTION [002] The present invention relates to extractive oxidation processes using an ionic phase containing an ionic liquid combined with an Fe(II) complex with an ionophilic binder system with catalytic function of activation of the oxidizing agent. [003] In extractive oxidation processes contaminants are removed from an oily phase, generally from hydrocarbons, including those of fossiJ origin, normally rich in heteroatomic compounds, using mild conditions of atmospheric pressure and temperature. The ionophilic binder system is responsible for maintaining the iron cation in the ionic phase, operating as a catalyst, without it being leached into the oily phase. BACKGROUND OF THE INVENTION [004] An untreated stream of hydrocarbons of fossil origin normally contains heteroatomic compounds, classified as contaminants or impurities. The heteroatomic compounds most commonly found in these streams are compounds generally containing sulphur atoms (S) and nitrogen atoms (N), as well as compounds containing oxygen (0), and metals such as nickel (Ni), iron (Fe), copper (Cu), sodium (Na) and vanadium (V). [005] Compounds containing sulphur (S) and nitrogen (N) are the most prevalent contaminants and are present in various types of petroleum. These sulphur-containing and nitrogen-containing contaminants cause problems in handling (reduction of the efficiency of catalysts in the refinery), transport 2 (corrosion in oil and gas pipelines) and use of derivatives (they cause environmental pollution if present in fuels derived from petroleum). [006] A table is presented below that gives examples of the elemental composition of crude oil (wt%). Hydrogen 11-14% Carbon 83-87% Sulphur 0.06-6% Nitrogen 0.11-1.7% Oxygen 0.1-2% Metals up to 0.3% [007] Alternative processes for removing sulphur compounds and nitrogen compounds present in streams of fossil hydrocarbons have been developed both for adjusting the technical and environmental specifications of the products and for minimizing the harshness of conventional processes. [008] In the oil refining industry, some treatment processes are used conventionally for removing sulphur and nitrogen present in these contaminants, for example hydrofining processes, such as hydrodesulphurization (HOS) and hydrodenitrogenation (HON). [009] The conventional processes of hydrodesulphurization (HOS) and hydrodenitrogenation (HON) consist respectively of removing sulphur and nitrogen from contaminants of various petroleum cuts by means of hydrogenation reactions in the presence of catalysts, which are typically supported metal sulphides. However, certain sulphur-containing and nitrogen-containing contaminants are difficult to treat by the conventional routes, for example some nitrogen-containing compounds poison the catalyst, and require harsher operating conditions. It then becomes necessary to develop new catalysts and/or alternative routes of treatment processes, such as the methods of extractive oxidation of heteroatomic compounds. In extractive oxidation processes the contaminants are removed and/or made inert or converted to other compounds that have greater affinity for solvents that are immiscible in the oil or for adsorbents. 3 [001 0] The prior art describes alternative treatment processes for removing heteroatomic compounds from hydrocarbon streams. [0011] Patents US 6,544,409 and US 7,153,414 teach extractive oxidation processes for the pre-treatment of distillates from crude oils, rich in heteroatomic contaminants, that are applicable to the pre-treatment of hydrocarbon streams. Both documents state that the method of extractive oxidation performed with peracids possesses advantages, such as removing certain compounds that are difficult to remove by hydrofining, such as substituted and nitrogenated dibenzothiophenes, and pyridine and quinoline compounds. These compounds are strong deactivators of supported metal sulphide catalysts. [0012] One way of achieving improvements in the process for removing heteroatomic compounds comprises addition of ionic liquids to a reaction mixture. Ionic liquids are known, such as molten salts at a temperature below 1QQ?C, which normally consist of salts derived from alkylammonium, phosphonium and imidazolium cations, having as anions (counter-ion) structures such as BF4-, PF6-, CF3SQ3-, (CF3SO2)2N-, CF3CO2- (P. Wasserscheid, T. Welton; Ionic Liquids in Synthesis, VCH-Wiley, Weinheim, 2002; J. Dupont; R.F. De Souza, P.A.Z. Suarez; Chem. Rev.; 2002, 102, 3667; P. Wasserscheid, W. Keim; Angew. Chem. Int. Ed.; 2000, 39, 3773; T. Welton; Chem. Rev.; 1999, 99, 2071). [0013] Owing to their intrinsic characteristics, ionic liquids can act as solvents and/or catalysts in chemical reactions, and as ions are involved in