Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
  • C10G65/00—Treatment of hydrocarbon oils by two or more hydrotreatment processes only
  • C10G65/02—Treatment of hydrocarbon oils by two or more hydrotreatment processes only plural serial stages only
  • C10G65/10—Treatment of hydrocarbon oils by two or more hydrotreatment processes only plural serial stages only including only cracking steps
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S585/00—Chemistry of hydrocarbon compounds
  • Y10S585/929—Special chemical considerations
  • Y10S585/946—Product is waxy polymer

Definitions

• the present invention relates to a process for converting paraffins from the Fischer-Tropsch process.
• it uses bifunctional zeolitic catalysts for the hydrocracking of paraffins originating from the Fischer-Tropsch process, making it possible to obtain highly recoverable products such as kerosene, diesel oil and especially base oils.
• the present invention relates to a process for the conversion of paraffins from the Fischer-Tropsch process using a bifunctional catalyst containing a faujasite type zeolite which can be specially modified, dispersed in a matrix generally based on alumina, silica, silica-alumina, alumina-boron oxide, magnesia, silica-magnesia, zirconia, titanium oxide or based on a combination of at least two of the preceding oxides, or based on a clay, or d 'a combination of the preceding oxides with clay.
• the role of this matrix is in particular to help shape the zeolite, in other words to produce it in the form of agglomerates, beads, extrudates, pellets, etc., which can be placed in an industrial reactor.
• the proportion of matrix in the catalyst is between 20 and 97% by weight and preferably between 50 and 97% by weight.
• the synthesis gas (CO + H2) is catalytically transformed into oxygenated products and hydrocarbons, essentially linear, in gaseous, liquid or solid form.
• These products are free of heteroatomic impurities such as for example sulfur, nitrogen or metals.
• these products cannot be used as such, in particular because of their cold resistance properties which are not very compatible with the usual uses of petroleum fractions.
• the pour point of a linear hydrocarbon containing 20 carbon atoms per molecule (boiling point equal to approximately 344 ° C, that is to say included in the diesel cut) is +37 ° C approximately when the customs specifications require a pour point below -7 ° C for commercial gas oils.
• These hydrocarbons from the Fischer-Tropsch process must then be transformed into more recoverable products such as kerosene and diesel oil after having undergone catalytic hydrocracking reactions.
• the catalysts used in hydrocracking are all of the bifunctional type combining an acid function with a hydrogenating function.
• the acid function is provided by supports of large surfaces (generally, 150 to 800 m2.g ⁇ 1) having a surface acidity, such as halogenated aluminas (chlorinated or fluorinated in particular), combinations of boron oxides and aluminum, amorphous silica-aluminas and zeolites.
• the hydrogenating function is provided either by one or more metals from group VIII of the periodic table of elements, such as iron, cobalt, nickel, ruthenium, rhodium, palladium osmium, iridium and platinum, or by a combination of at least one metal of group VI of the periodic table such as chromium, molybdenum and tungsten and of at least one metal of group VIII.
• group VIII of the periodic table of elements such as iron, cobalt, nickel, ruthenium, rhodium, palladium osmium, iridium and platinum
• at least one metal of group VI of the periodic table such as chromium, molybdenum and tungsten and of at least one metal of group VIII.
• the balance between the two acid and hydrogenating functions is the fundamental parameter which governs the activity and the selectivity of the catalyst.
• a weak acid function and a strong hydrogenating function give catalysts which are not very active and selective towards isomerization whereas a strong acid function and a weak hydrogenating function give very active and selective catalysts towards cracking. It is therefore possible, by judiciously choosing each of the functions, to adjust the activity / selectivity pair of the catalyst.
• the acid carriers there are, in order of increasing acidity, aluminas, halogenated aluminas, amorphous silica-aluminas and zeolites.
• Patent EP-A-147873 describes a catalyst comprising an element of group VIII on a support during a process carrying out the Fischer-Tropsch synthesis reaction and then hydrocracking.
• Patent application EP-B-356560 describes the preparation of a very specific Y zeolite which can be used in a catalyst of the Fischer-Tropsch reaction or in a hydrocracking catalyst.
• US-A-4,684,756 describes the treatment of products of the Fischer-Tropsch synthesis in a hydrocracking process.
• the catalyst used contains noble (Palladium, platinum) or non-noble (Nickel, Molybdenum, Tungsten) metals deposited on an amorphous support (acid clay, silica-alumina) or a zeolite.
• the catalyst of the present invention contains a Y zeolite with a faujasite structure (Zeolite Molecular Sieves Structure, chemistry and use, DW Breck, J. Willey and Sons, 1973).
• Y zeolites that can be used, preferably use a stabilized Y zeolite, commonly called ultrastable or USY, either in the form partially exchanged with rare earth cations of atomic number. 57 to 71 inclusive so that its rare earth content expressed in% by weight of rare earth oxides is less than 10% by weight, preferably less than 6% by weight, or in hydrogen form.
• the zeolite used in the catalyst of the present invention is preferably an acidic zeolite HY characterized by different specifications: a SiO2 / Al2O3 molar ratio greater than 4.5 and preferably between 8 and 70; a sodium content of less than 1% by weight and preferably less than 0.5% by weight, determined on the zeolite calcined at 1100 ° C; a crystalline parameter a o of the elementary mesh less than 24.70 x 10 ⁇ 10 meter and preferably between 24.24 x 10 ⁇ 10 meter and 24.55 x 10 ⁇ 10 meter; a specific surface area determined by the BET method greater than 400m2 / g and preferably greater than 550m2 / g.
• This zeolite is known from the prior art (French patent 2,561,946).
• the NaY zeolite generally used as raw material has more than 5% by weight of sodium and has a SiO2 / Al2O3 molar ratio of between 4 and 6. It is not used as such, but it must be subjected to a series of treatments stabilization aimed at increasing its acidity and thermal resistance.
• the zeolite Y stabilizations are most commonly carried out, either by the introduction of rare earth cations or group IIA metal cations, or by hydrothermal treatments. All these treatments are described in French patent FR 2 561 946.
• the HY or NH4Y zeolite thus obtained or any HY or NH4Y zeolite exhibiting these characteristics can be introduced at this stage, into the matrix described above in the form of an alumina gel.
• the catalyst thus obtained comprises, by weight, from 20 to 97% of matrix, 3 to 80% of zeolite and at least one hydro-dehydrogenation component.
• One of the preferred methods in the present invention, for the introduction of the zeolite into the matrix consists in co-kneading the zeolite and the gel then in passing the dough thus obtained through a die to form extrudates of diameter between 0.4 and 4 millimeters.
• the hydro-dehydrogenation component of the catalyst of the present invention is for example at least one compound, for example an oxide, of a metal from group VIII of the periodic table of the elements, (in particular nickel, palladium or platinum ), or a combination of at least one compound of a group VI metal (especially molybdenum or tungsten) and at least one compound of a group VIII metal (especially cobalt or nickel) of the periodic classification of the elements.
• the concentrations of the metal compounds are the following: between 0.01 and 5% by weight of group VIII metals, and preferably between 0.03 and 3% by weight, in the case where it is they are only noble metals of the palladium or platinum type; between 0.01 and 15% by weight of group VIII metals, and preferably between 0.05 and 10% by weight, in the case of non-noble metals of group VIII of the nickel type for example; when at least one metal or group VIII metal compound and at least one group VI metal compound are used, between 5 and 40% by weight of a combination of at least one compound is used (oxide in particular) of a group VI metal (molybdenum or tungsten in particular) and at least one metal or compound of metal from group VIII (cobalt or nickel in particular) and preferably between 12 and 30% by weight, with a weight ratio (expressed as metal oxides) metals of group VIII to metals of group VI between 0.05 and 0.8 and preferably between 0.13 and 0.5.
• This catalyst may advantageously contain phosphorus; in fact, it is known in the prior art that this compound provides two advantages to hydrotreatment catalysts: ease of preparation during in particular the impregnation of nickel and molybdenum solutions, and better hydrogenation activity.
• the phosphorus content expressed as a concentration of phosphorus oxide P2O5, will be less than 15% by weight and preferably less than 10% by weight.
• the hydrogenating function as defined above can be introduced into the catalyst at various levels of the preparation and in various ways as described in French patent FR 2 561 946.
• the NH4Y or HY zeolite catalysts as described above undergo, if necessary, a final calcination step in order to finally obtain a Y zeolite catalyst in hydrogen form.
• the catalysts thus finally obtained are used for the hydrocracking of paraffin feeds from the Fischer-Tropsch process under the following conditions: hydrogen is reacted with the feed in contact with a catalyst 1 contained in the reactor R1 (or first reaction zone R1) whose role is to eliminate unsaturated and oxygenated hydrocarbon molecules produced during the Fischer-Tropsch synthesis.
• the effluent from reactor R1 is brought into contact with a second catalyst 2 contained in reactor R2 (or second reaction zone R2) whose role is to ensure the hydrocracking reaction.
• the effluent from reactor 2 is divided into different conventional petroleum fractions such as gas, light petrol, heavy petrol, kerosene, diesel and "residue”; the fraction called “residue” represents the heaviest fraction obtained during fractionation.
• the choice of temperatures during the effluent fractionation step from reactor 2 can vary greatly depending on the specific needs of the refiner. Adjusting the reaction temperature provides variable yields for each cut.
• the catalyst 1 of the first stage consists of an alumina-based matrix, preferably not containing a zeolite, and of at least one metal having a hydro-dehydrogenating function.
• Said matrix can also contain silica-alumina, boron oxide, magnesia, zirconia, titanium oxide, clay or a combination of these oxides.
• the hydro-dehydrogenating function is provided by at least one metal or compound of group VIII metal such as nickel and cobalt in particular. It is possible to use a combination of at least one metal or compound of group VI metal (in particular molybdenum or tungsten) and of at least one metal or compound of group VIII metal (in particular cobalt or nickel).
• the total concentration of metals of groups VI and VIII, expressed in metal oxides, is between 5 and 40% by weight and preferably between 7 and 30% by weight and the weight ratio expressed in metal oxide metal (or metals) of the group VI on metal (or metals) of group VIII is between 1.25 and 20 and preferably between 2 and 10.
• this catalyst may contain phosphorus.
• the phosphorus content, expressed as a concentration of phosphorus oxide P2O5, will be less than 15% by weight and preferably less than 10% by weight.
• the catalyst contained in the R2 repeater is the catalyst described in the main part of the text. It especially comprises at least one HY zeolite characterized by a SiO2 / Al2O3 molar ratio greater than 4.5 and preferably between 8 and 70; a sodium content of less than 1% by weight and preferably less than 0.5% by weight determined on the zeolite calcined at 1100 ° C; a crystalline parameter a o of the elementary mesh less than 24.70 x 10 ⁇ 10 meter and preferably between 24.24 x 10 ⁇ 10 meter and 24.55 x 10 ⁇ 10 meter; a specific surface area determined by the BET method greater than 400m2.g ⁇ 1 and preferably greater than 550m2.g ⁇ 1.
• the alumina gel used is supplied by the company Condisputeda under the reference SB3. After mixing, the dough obtained is extruded through a die with a diameter of 1.4mm. The extrudates are calcined and then impregnated to dryness with a solution of mixture of ammonium heptamolybdate, nickel nitrate and orthophosphoric acid, and finally calcined in air at 550 ° C.
• the weight contents, expressed as active oxides, are as follows (relative to the catalyst):
• a HY zeolite of formula H AlO2 (SiO2) 3.3 is used, supplied by the company Contéka under the reference CBV500.
• This zeolite whose characteristics are: is kneaded with SB3 type alumina supplied by the company Condisputeda. The kneaded dough is then extruded through a die of 1.4 min diameter. The extrudates are then calcined and then impregnated to dryness with a solution of a mixture of ammonium heptamolybdate, nickel nitrate and orthophosphoric acid, and finally calcined in air at 550 ° C.
• the weight contents, expressed as active oxides, are as follows (relative to the catalyst):
• the NaY zeolite is subjected to two exchanges in ammonium chloride solutions so that the sodium level is 2.6% by weight.
• the product is then introduced into a cold oven and calcined in air up to 400 ° C. At this temperature, a flow of water corresponding to a partial pressure of 50.7 kPa is introduced into the calcination atmosphere. The temperature is then brought to 565 ° C for two hours.
• the product is then subjected to an exchange with an ammonium chloride solution followed by a very gentle acid treatment under the following conditions: volume of hydrochloric acid 0.4 N on weight of solid of 10, duration of 3 hours.
• the sodium level then drops to 0.6% by weight, the SiO2 / Al2O3 ratio is 7.2.
• This product is then subjected to a brutal calcination in a static atmosphere at 780 ° C. for 3 hours, then again taken up in acid solution with hydrochloric acid of normality 2 and a volume ratio of solution to weight of zeolite of 10.
• the crystalline parameter is 24.28 x 10 ⁇ 10 meter, the specific surface of 825m2 / g, the water recovery capacity is 11.7, the sodium ion recovery capacity is 1.0 expressed by weight of sodium per 100 grams of dealuminated zeolite .
• the zeolite thus obtained is kneaded with alumina of the SB3 type supplied by the company Condisputeda. The kneaded dough is then extruded through a die with a diameter of 1.4 mm.
• the extrudates are then calcined and then impregnated to dryness with a solution of a mixture of ammonium heptamolybdate, nickel nitrate and orthophosphoric acid, and finally calcined in air at 550 ° C.
• the weight contents, expressed as active oxides, are as follows (relative to the catalyst):
• silica-alumina prepared in the laboratory containing 25% by weight of SiO2 and 75% by weight of Al2O3. 3% by weight of pure nitric acid is added to 67% relative to the dry weight of silica-alumina powder in order to obtain the peptization of the powder.
• the dough obtained is extruded through a die with a diameter of 1.4mm.
• the extrudates are calcined then impregnated to dryness with a solution of a salt of platinum chloride tetramine Pt (NH3) platineCl2 and finally calcined in air at 550 ° C.
• the platinum content of the final catalyst is 0.6% by weight.
• the catalytic test unit comprises a single reactor in a fixed bed, with upward flow of charge ("up-flow"), into which 80 ml of catalyst is introduced.
• Catalysts A, B and C are sulfurized by an n-hexane / DMDS + aniline mixture up to 320 ° C.
• Catalyst D undergoes a reduction under hydrogen in situ in the reactor.
• the total pressure is 5 MPa
• the hydrogen flow rate is 1000 liters of gaseous hydrogen per liter of charge injected
• the hourly volume speed is 0.5.
• the catalytic performances are expressed by the temperature which makes it possible to reach a net conversion level of 50% and by the gross selectivity. These catalytic performances are measured on the catalyst after a stabilization period, generally at least 48 hours, has been observed.
• the net CN conversion is taken equal to:
• the gross selectivity SB is taken equal to:
• Example 3 In the case of Example 3, a yield of 32% by weight of oil relative to the residue is obtained by dewaxing, said oil having an IV of 152.
• zeolite makes it possible to decrease the net conversion temperature CN substantially, since a gain of approximately 100 ° C. is observed between the catalyst without zeolite (catalyst of Example 1) and the catalysts in container (catalysts of Examples 2 and 3). Likewise, a gain of approximately 78 ° C. is observed between the silica-alumina-based catalyst (catalyst of Example 4) and the catalysts containing it (catalysts of Examples 2 and 3).
• Example 3 Compared to a zeolite which has not undergone extensive dealumination, such as that of Example 2, the use of a dealuminated zeolite such as that used in Example 3 makes it possible to clearly improve the selectivity.
• selectivity varies greatly with conversion.
• the selectivity is higher the lower the conversion.
• Example 6 Evaluation of catalysts A, B, C and D in a hydrocracking test with recycling of the "residue" fraction
• the charge and the test conditions are identical to those of Example 5.
• the use of recycling the 380+ fraction, at the inlet of the reactor, makes it possible to obtain a total conversion of the charge.
• the term conversion by pass is used which represents the conversion actually carried out at the level of the catalyst.
• the gross selectivity SB is taken equal to:
• Example 5 the use of a zeolite makes it possible to reduce the iso-conversion temperature substantially. Compared to a zeolite that has not undergone extensive dealumination like that of Example 2, the use of a dealuminated zeolite such as that used in Example 3 makes it possible to very clearly improve the selectivity .

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• Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
• Catalysts (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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• 1991
  • 1991-05-21 FR FR9106141A patent/FR2676750B1/fr not_active Expired - Lifetime
• 1992
  • 1992-05-17 DZ DZ920050A patent/DZ1581A1/fr active
  • 1992-05-19 NO NO921981A patent/NO305486B1/no not_active IP Right Cessation
  • 1992-05-20 EP EP92401371A patent/EP0515270B1/fr not_active Expired - Lifetime
  • 1992-05-20 ES ES92401371T patent/ES2061325T3/es not_active Expired - Lifetime
  • 1992-05-20 DE DE69200297T patent/DE69200297T2/de not_active Expired - Fee Related
  • 1992-05-20 ZA ZA923659A patent/ZA923659B/xx unknown
  • 1992-05-21 US US07/886,225 patent/US5345019A/en not_active Expired - Fee Related

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