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
  • C10G45/00—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds
  • C10G45/58—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds to change the structural skeleton of some of the hydrocarbon content without cracking the other hydrocarbons present, e.g. lowering pour point; Selective hydrocracking of normal paraffins
  • C10G45/60—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds to change the structural skeleton of some of the hydrocarbon content without cracking the other hydrocarbons present, e.g. lowering pour point; Selective hydrocracking of normal paraffins characterised by the catalyst used
  • C10G45/64—Refining of hydrocarbon oils using hydrogen or hydrogen-generating compounds to change the structural skeleton of some of the hydrocarbon content without cracking the other hydrocarbons present, e.g. lowering pour point; Selective hydrocracking of normal paraffins characterised by the catalyst used containing crystalline alumino-silicates, e.g. molecular sieves

Definitions

• the present invention relates to a method for improving the pour point of fillers containing paraffins, linear and / or sparingly branched, long (more than 10 carbon atoms), in particular to convert, with good efficiency, loads with high pour points in at least one section having a reduced pour point.
• This cut can be a middle distillate and / or an oil base, which then has a high viscosity index.
• This operation can be carried out by extraction with solvents such as propane or methyl ethyl ketone, we then speak of propane or methyl dewaxing ethyl ketone (MEK).
• solvents such as propane or methyl ethyl ketone
• MEK methyl dewaxing ethyl ketone
• Another means is a selective cracking of the most linear paraffinic chains. long which leads to the formation of lower molecular weight compounds including part of it can be removed by distillation.
• zeolites are among the most no longer used.
• the idea that prevails in their use is that there are structures zeolites whose pore openings are such that they allow entry into their microporosity of long linear paraffins or very little branched but in exclude branched paraffins, naphthenes and aromatics. This phenomenon thus leads to a selective cracking of linear or very poorly branched paraffins.
• Zeolite catalysts with intermediate pore sizes such as that ZSM-5, ZSM-11, ZSM-12, ZSM22, ZSM-23, ZSM-35 and ZSM-38 have been described for their use in these processes.
• the Applicant has focused its research efforts on the development of a process improved pour point reduction thanks to the use of catalyst based on NU-86 zeolite. This process, applied to heavy cuts, makes it possible to produce times middle distillates with reduced pour point and a residue including bases oils with low pour point and high viscosity index.
• the subject of the invention is a method for improving the pour point of a paraffinic charge comprising paraffins of more than 10 carbon atoms, in which the charge to be treated is brought into contact with a catalyst based on NU-86 zeolite and comprising at least one hydro-dehydrogenating element, at a temperature between 170 and 500 ° C, a pressure between 1 and 250 bar and an hourly volume speed between 0.05 and 100 h -1 , in the presence of hydrogen at a rate of 50 to 2000 I / I of charge.
• the product obtained is fractionated so as to obtain at least one cut including at least one middle distillate with reduced pour point and a residue including the oil bases with reduced pour point and index of high viscosity.
• the NU-86 zeolite, in hydrogen form, designated by H-NU-86 and obtained by calcination and / or ion exchange of the crude synthetic NU-86 zeolite, used in the process according to the invention as well as its mode of synthesis are described in patent EP-0463768 A2.
• This NU-86 zeolite is characterized by an X-ray diffraction table which is as follows: X-ray diffraction table for zeolite H-NU-86 dhki ( ⁇ ) I / Io 11.80 ⁇ 0.15 m ⁇ 11.10 ⁇ 0.15 f to m ⁇ 10.60 ⁇ 0.15 f to m ⁇ 8.60 ⁇ 0.15 f 4.24 ⁇ 0.10 f to m 4.16 ⁇ 0.10 f to m ⁇ 4.10 ⁇ 0.10 f to m ⁇ 3.93 ⁇ 0.08 TF 3.85 ⁇ 0.08 F to TF 3.73 ⁇ 0.08 m 3.54 ⁇ 0.06 f 3.10 ⁇ 0.06 f 2.07 ⁇ 0.04 f
• pore opening with 10, 11 or 12 tetrahedral atoms is understood to mean pores consisting of 10, 11 or 12 sides.
• zeolites NU-86 comprising silicon and at least one element T chosen from the group formed by Al, Fe, Ga, B, and preferably aluminum.
• the NU-86 zeolite used has been dealuminated or more in general, at least part of the element T has been removed, and it then has a Si / T global atomic advantageously greater than approximately 20.
• Element extraction T of the zeolitic framework (or network) is preferably carried out, by at least a heat treatment, possibly carried out in the presence of water vapor, followed at least one acid attack or by a direct acid attack, by at least a solution of a mineral or organic acid.
• the overall atomic Si / T ratio of said zeolite is greater than about 16 and preferably about 20, preferably greater than about 22 and even more preferably between about 22 and about 300, or about 250.
• the "dealuminated" NU-86 zeolite is at least in part, preferably substantially totally, in acid form, that is to say in hydrogen form (H +).
• the report atomic Na / T is generally less than 0.7% and preferably less than 0.6% and even more preferably less than 0.4%.
• this process makes it possible to convert a charge having a high pour point into a product having a lower pour point.
• It can be a medium distillate type cup with reduced pour point (diesel fuels by example) and / or an oil base with reduced pour point and high viscosity index.
• the load is composed, among other things, of linear and / or slightly branched paratfines containing at least 10 carbon atoms, preferably from 15 to 50 carbon atoms carbon and advantageously from 15 to 40 carbon atoms.
• An advantage of the catalyst comprising the NU-86 molecular sieve is that it does not conduct not too much formation of light products.
• the catalyst comprises at least one hydro-dehydrogenating function, for example a group VIII metal or a combination of at least one metal or composed of group VIII and at least one metal or compound of group VI, and the reaction is carried out under the conditions described below.
• hydro-dehydrogenating function for example a group VIII metal or a combination of at least one metal or composed of group VIII and at least one metal or compound of group VI, and the reaction is carried out under the conditions described below.
• NU-86 zeolite according to the invention allows, in particular, the production of products with low pour point and also products with high viscosity index, with good yields.
• the NU-86 zeolite has an Si / T atomic ratio (preferred Al) of between 8 and 1000 and in particular between 8.5 and 16 for the zeolites obtained by synthesis, and a Si / T atomic ratio of more than 16 and advantageously more than 20 for the zeolites in which at least part of the element T has been removed.
• Si / T atomic ratio preferred Al
• the first method known as direct acid attack comprises a first calcination step under dry air flow, at a temperature generally between about 450 and 550 ° C, which aims to remove the organic structuring agent present in the microporosity zeolite, followed by a step of treatment with an aqueous solution of a mineral acid such as HNO 3 or HCl or organic such as CH 3 CO 2 H. This last step can be repeated as many times as necessary to get the desired dealumination level. Between these two steps, it is possible to carry out one or more ionic exchanges with at least one NH 4 NO 3 solution , so as to eliminate at least in part, preferably practically completely, the alkaline cation, in particular sodium. Likewise, at the end of the dealumination treatment by direct acid attack, it is possible to carry out one or more ionic exchanges with at least one NH 4 NO 3 solution , so as to eliminate the residual alkaline cations and in particular sodium.
• the most critical parameters are the temperature treatment with the aqueous acid solution; the latter's concentration, his nature, the ratio between the quantity of acid solution and the mass of zeolite treated, the duration of treatment and the number of treatments performed.
• the second method called thermal treatment (in particular with steam or "steaming") + acid attack comprises, firstly, calcination under dry air flow, at a temperature generally between approximately 450 and 550 ° C, which aims to eliminate the organic structuring agent occluded in the microporosity of the zeolite. Then the solid thus obtained is subjected to one or more ionic exchanges by at least one NH 4 NO 3 solution , so as to eliminate at least in part, preferably practically completely, the alkaline cation, in particular the sodium, present in the cationic position. in the zeolite.
• the zeolite thus obtained is subjected to at least one structural dealumination cycle, comprising at least one heat treatment carried out, optionally and preferably in the presence of water vapor, at a temperature generally between 550 and 900 ° C., and optionally followed by at least one acid attack with an aqueous solution of a mineral or organic acid.
• the calcination conditions in the presence of water vapor temperature, water vapor pressure and duration of treatment
• the post-calcination acid attack conditions are adjusted so as to obtain the desired dealumination level.
• the dealumination cycle of the frame comprising at least one heat treatment step, optionally carried out and preferably in the presence of water vapor, and at least one attack step in the middle NU-86 zeolite acid, can be repeated as many times as necessary to obtain the dealuminated NU-86 zeolite having the desired characteristics.
• the heat treatment possibly carried out and preferably in presence of water vapor, several successive acid attacks, with solutions in acid of different concentrations, can be operated.
• a variant of this second calcination method may consist in carrying out the heat treatment of the NU-86 zeolite containing the organic structuring agent, at a temperature generally between 550 and 850 ° C., optionally and preferably in the presence of water vapor. In this case the stages of calcination of the organic structuring agent and dealumination of the framework are carried out simultaneously. Then, the zeolite is optionally treated with at least one aqueous solution of a mineral acid (for example HNO3 or HCl) or organic (CH 3 CO 2 H for example).
• a mineral acid for example HNO3 or HCl
• organic CH 3 CO 2 H for example
• the solid thus obtained can optionally be subjected to at least one ion exchange with at least one NH 4 NO 3 solution , so as to eliminate practically any alkaline cation, in particular sodium, present in the cationic position in the zeolite.
• the sieve (zeolite NU-86) generally contains at least one hydro-dehydrogenating element, for example at least one group VIII metal, preferably a noble metal and advantageously chosen from the group formed by Pt or Pd, which is introduced into the molecular sieve, for example by dry impregnation, by ion exchange or any other method known to those skilled in the art.
• group VIII metal preferably a noble metal and advantageously chosen from the group formed by Pt or Pd, which is introduced into the molecular sieve, for example by dry impregnation, by ion exchange or any other method known to those skilled in the art.
• the content of metal thus introduced is generally less than 5%, preferably less than 3% and generally of the order of 0.5% to 1% by weight.
• the molecular sieve according to the invention is previously shaped.
• the molecular sieve can be subjected to the deposition of at least one group VIII metal preferably chosen from the group formed by platinum and palladium, and shaped by any technique known to those skilled in the art. It can in particular be mixed with a matrix, generally amorphous, for example to a wet alumina gel powder. The the mixture is then shaped, for example by extrusion through a die.
• the molecular sieve content of the mixture thus obtained is generally understood between 0.5 and 99.9% and advantageously between 5 and 90% by weight per ratio to the mixture (molecular sieve + matrix).
• molecular sieve will be used to designate the support. + matrix.
• the shaping can be carried out with matrices other than alumina, such as for example magnesia, amorphous silica-aluminas, natural clays (kaolin, bentonite, sepiolite, attapulgite), silica, titanium oxide, boron oxide, zirconia, aluminum phosphates, titanium phosphates, zirconium phosphates, coal and their mixtures.
• matrices other than alumina such as for example magnesia, amorphous silica-aluminas, natural clays (kaolin, bentonite, sepiolite, attapulgite), silica, titanium oxide, boron oxide, zirconia, aluminum phosphates, titanium phosphates, zirconium phosphates, coal and their mixtures.
• Other techniques than extrusion such as pastillage or coating, can be used.
• the group VIII hydrogenating metal preferably Pt and / or Pd
• the group VIII hydrogenating metal can also be deposited on the support by any process known to those skilled in the art and allowing the deposition of the metal on the molecular sieve.
• platinum or palladium usually uses a platinum tetramine complex or a tetramine complex palladium: these will then be deposited almost entirely on the sieve molecular.
• This cation exchange technique can also be used for deposit the metal directly on the molecular sieve powder, before mixing possible with a matrix.
• group VIII metal or metals
• calcination in air or oxygen usually between 300 and 600 ° C for 0.5 to 10 hours, preferably between 350 ° C and 550 ° C for 1 to 4 hours.
• We can then carry out a reduction under hydrogen generally at a temperature between 300 and 600 ° C for 1 to 10 hours, preferably one will operate between 350 ° and 550 ° C for 2 to 5 hours.
• a competing agent for example hydrochloric acid.
• the catalyst is as before subjected to calcination and then reduced under hydrogen as indicated above.
• the hydro-dehydrogenating element can also be a combination of at least one metal or compound of group VI (for example molybdenum or tungsten) and at least minus a Group VIII metal or compound (eg nickel or cobalt).
• the total concentration of metals of groups VI and VIII, expressed as metal oxides relative to the support, is generally between 5 and 40% by weight, preferably between 7 and 30% by weight.
• the weight ratio (expressed in oxides group VIII metals over group VI metals is preferably between 0.05 and 0.8; preferably between 0.13 and 0.5.
• the previous preparation methods can be used to deposit these metals.
• This type of catalyst can advantageously contain phosphorus, the content of which, expressed as phosphorus oxide P 2 O 5 relative to the support, will generally be less than 15% by weight, preferably less than 10% by weight.
• the charges which can be treated according to the method of the invention are advantageously fractions having relatively pour points tops whose value you wish to decrease.
• the method according to the invention can be used to treat various loads ranging from relatively light fractions such as kerosene and jet fuel up to fillers with higher boiling points such as middle distillates, vacuum residues, gas oils.
• the load to be treated is in most cases a C 10 + cut with an initial boiling point greater than about 175 ° C, preferably a cut with an initial boiling point of at least 280 ° C.
• heavy fillers are used, that is to say constituted for at least 80% by volume of compounds with boiling points of at least 350 ° C., preferably between 350-580 °. C, and advantageously at least 380 ° C.
• the process according to the invention is particularly suitable for treating paraffinic distillates such as middle distillates which include gas oils, kerosene, jet fuels, for treating residues under vacuum and all other fractions whose pour point and viscosity must be adapted to fit within the specifications, and for example middle distillates from FCC (LCO and HCO) and hydrocracking residues.
• paraffinic distillates such as middle distillates which include gas oils, kerosene, jet fuels
• the fillers which can be treated according to the process of the invention may contain paraffins, olefins, naphthenes, aromatics and also heterocycles and with a significant proportion of high-weight n-paraffins molecular and very poorly branched paraffins also of high molecular weight.
• Typical fillers which can be advantageously treated according to the invention generally have a pour point above 0 ° C.
• the resulting products of the treatment according to the process have pour points below 0 ° C and preferably below about -10 ° C.
• These fillers have n-paraffin contents, more than 10 atoms of carbon, of high molecular weight and in paraffins, with more than 10 carbon atoms, very few branched also of high molecular weight, higher than 30% and up to about 90%, or in some cases even more than 90% by weight.
• the process is particularly advantageous when this proportion is at least 60% by weight.
• the process can also be applied to other compounds containing an n-alkane chain as defined above, for example n-alkylcycloalkane compounds, or containing at least one aromatic group.
• the rate of hydrogen used and expressed in liters of hydrogen per liter of charge is between 50 and about 2000 liters of hydrogen per liter of charge and preferably between 100 and 1500 liters of hydrogen per liter of charge.
• the feed to be treated preferably has a lower content of nitrogen compounds at about 200 ppm by weight and preferably less than 100 ppm by weight.
• Content sulfur is less than 1000 ppm by weight, preferably less than 500 ppm and even more preferably less than 200 ppm by weight.
• the metal content of the charge, such as Ni or V, is extremely reduced, i.e. less than 50 ppm weight, preferably less than 10 ppm weight and even more so preferred less than 2 ppm by weight.
• the product obtained, after treatment of the heavy load with the zeolite catalyst NU-86, is divided into at least one section including at least one medium to distillate reduced pour point, and a residue including point oil bases reduced flow and high viscosity index.
• the middle distillate can be a kerosene (generally considered cut where points boiling 150 - less than 250 ° C), a diesel fuel (heavier cut than Kerosene, generally considered to be at least 250 ° C and less than 400 ° C, or less than 380 ° C).
• the oil is then in the residue 380 + or 400+. cutting points can be more or less variable depending on the operator's constraints.
• the raw material used is a NU-86 zeolite, which is prepared according to the example. 2 of patent EP 0 463 768 A2 and has an overall atomic Si / Al ratio equal to 10.2 and an Na / Al atomic ratio equal to 0.25.
• This NU-86 zeolite first undergoes a so-called dry calcination at 550 ° C. under a flow of dry air for 9 hours. Then the solid obtained is subjected to four ionic exchanges in a solution of NH 4 NO 3 10N, at approximately 100 ° C. for 4 hours for each exchange.
• the rate of crystallinity is therefore expressed as a percentage in relation to a reference, it matters to choose well, because the relative intensity of the lines varies according to the nature, the proportion and position of the different atoms in the structural unit, and in particular of the cations and of the structuring.
• the reference chosen is the calcined form under dry air exchanged 3 times successively with an ammonium nitrate solution NU-86 zeolite.
• the crystallites of the NU-86 zeolite are in the form of crystals whose size vary from 0.4 ⁇ m to 2 ⁇ m.
• the NH4-NU-86/1 zeolite is kneaded with SB3 type alumina supplied by the company Condisputeda.
• the kneaded dough is then extruded through a 1.2 mm diameter die.
• the extrudates are then calcined at 500 ° C for 2 hours in air then impregnated to dryness with a solution of platinum chloride tetramine [Pt (NH 3 ) 4 ] Cl 2 , and finally calcined in air at 550 ° C.
• the platinum content of the final catalyst C1 thus obtained is 0.7% by weight and the zeolite content expressed relative to the total mass of the catalyst is 20% by weight.
• Example 2 Evaluation of the catalyst C1 on a hydrocracking residue
• Catalyst C1 was evaluated to treat a hydrocracking residue from a distillate under vacuum.
• Catalyst C1 the preparation of which is described in Example 1, is used to prepare a base oil from the charge described above.
• the catalyst is reduced beforehand under hydrogen at 450 ° C. before the catalytic test in situ in the reactor. This reduction is carried out in stages. It consists of a plateau at 150 ° C for 2 hours, then a temperature rise up to 450 ° C at the speed of 1 ° C / min, then a plateau of 2 hours at 450 ° C.
• the hydrogen flow rate is 1000 liters of H 2 per liter of catalyst.
• the reaction takes place at 265 ° C, under a total pressure of 12 MPa, an hourly volume speed 2 h -1 and a hydrogen flow rate of 1000 liters of H 2 per liter of charge.
• the fractionation of the effluent allows a base oil to be collected as a residue and a middle distillate cut with boiling point 150-400 ° C (400 ° C being excluded) and light products.
• the net conversion to compounds 400 - (having a boiling point below 400 ° C.) is 25% by weight and the yield of base oil is 75% by weight.
• the diesel pour point is -33 ° C.
• This example shows all the advantage of using a catalyst according to the invention, which lowers the pour point of the initial charge, in this case a residue hydrocracking, while retaining a high viscosity index (VI).
• the zeolite of Example 1 is used.
• the zeolite is kneaded with alumina of the SB3 type supplied by the company Condisputeda.
• the kneaded dough is then extruded through a 1.2 mm diameter die.
• the extrudates are then calcined at 500 ° C for 2 hours in air then impregnated to dryness with a solution of platinum chloride tetramine [Pt (NH 3 ) 4 ] Cl 2 , and finally calcined in air at 550 ° C.
• the platinum content of the final catalyst thus obtained is 0.7% by weight and the zeolite content expressed relative to the total mass of the catalyst is 30% by weight.
• the catalyst was evaluated on a hydrocracking residue from a vacuum distillate to prepare a base oil.
• the catalyst is reduced beforehand under hydrogen at 450 ° C. before the catalytic test in situ in the reactor. This reduction is carried out in stages. It consists of a plateau at 150 ° C for 2 hours, then a temperature rise up to 450 ° C at the speed of 1 ° C / min, then a plateau of 2 hours at 450 ° C.
• the hydrogen flow rate is 1000 liters of H 2 per liter of catalyst.
• the reaction takes place at 300 ° C, under a total pressure of 12 MPa, an hourly volume speed 1.8 h -1 and a hydrogen flow rate of 1000 liters of H 2 per liter of charge. Under these operating conditions, the net conversion to compounds 400 - is 27% by weight and the yield of base oil is 73% by weight.
• Viscosity index VI 134 Pour point (° C) -16 Oil yield (% by weight) 73
• This example shows all the advantage of using a catalyst according to the invention, which lowers the pour point of the initial charge, in this case a residue hydrocracking, while retaining a high viscosity index (VI).

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• Chemical & Material Sciences (AREA)
• Crystallography & Structural Chemistry (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)
• Silicates, Zeolites, And Molecular Sieves (AREA)

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• 1997
  • 1997-11-21 BR BR9713447-3A patent/BR9713447A/pt not_active IP Right Cessation
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  • 1997-11-21 DE DE69722235T patent/DE69722235T2/de not_active Expired - Fee Related
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  • 1997-11-21 CA CA002272143A patent/CA2272143A1/fr not_active Abandoned
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