RU2518119C2 - Combined method of catalytic cracking in catalyst fluidised bed for producing high-quality hydrocarbon mixtures as fuel - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention is related to a combined method of conversion of oil-derived hydrocarbon fractions into high-quality hydrocarbon mixtures as fuel, which includes catalytic cracking of hydrocarbon fraction in catalyst fluidised bed with catalyst containing ERS-10 zeolite, where the specified catalyst contains at least two components, where the specified components represent: (a) a component containing one or more catalytic cracking catalysts in fluidised, and (b) a component containing ERS-10 zeolite for obtaining Light Cycle Gas Oil (LCGO), hydrotreatment of light cycle gas oil, interaction of hydrotreated light cycle gas oil obtained at the previous stage of hydrotreatment in presence of hydrogen with catalytic system. The invention also touches the method of catalytic cracking and a stage of catalytic cracking in fluidised bed.

EFFECT: production of high-quality hydrocarbons, conversion increase.

21 cl, 3 tbl, 1 ex

Description

The present invention relates to a combined method of catalytic cracking in a fluidized bed of catalyst (KKP), which allows to obtain high-quality hydrocarbon mixtures as fuel. Specifically, the invention relates to a combined process comprising a catalytic cracking step in a fluidized bed of a catalyst in which hydrocarbon fractions of petroleum origin are converted in the presence of a catalyst with at least two components containing ERS-10, in a mixture with a high content of light recycle gas oil (LHG), possessing high quality in terms of density and nature of aromatic compounds contained in them, which, after the separation stage and the hydrotreatment stage, are subjected to stage of quality improvement by treatment with hydrogen with a catalyst containing one or more metals selected from Pt, Pd, Ir, Ru, Rh and Re, and an acid aluminosilicate.

WO 2006/124175 describes a process for converting hydrocarbon fractions to produce olefins, aromatics and low sulfur diesel fuel, which comprises a catalytic cracking stage in a fluidized bed to produce olefins and, to a lesser extent, LHG, a step for converting a high boiling olefin fraction into ethylene and propylene and a hydrocracking step in which the LHR fraction is mainly converted to aromatics and, to a lesser extent, to low sulfur diesel fuel.

WO 2007/006473 describes a method for improving the quality of hydrotreated hydrocarbon mixtures used as fuel, which comprises contacting said mixtures with hydrogen in the presence of a catalyst system containing one or more metals selected from Pt, Pd, Ir, Ru, Rh and Re, and acidic aluminosilicate.

MI 2007A001610 describes a combined process comprising a catalytic cracking step in a fluidized bed of catalyst in which hydrocarbon fractions of petroleum origin are converted to a high LHR mixture, which, after the separation step and the hydrotreatment step, is subjected to a quality improvement step by treatment with hydrogen, with a catalyst containing one or more metals selected from Pt, Pd, Ir, Ru, Rh and Re, and an acidic aluminosilicate.

MI 2008A001036 describes a method in which ERS-10 zeolite is used as an additive in a method for cracking hydrocarbon mixtures.

A combined method has been discovered for producing high-quality hydrocarbon mixtures as a fuel, which includes a catalytic cracking stage in a fluidized bed of a catalyst (KKP), performed in the presence of a catalyst with at least two components containing ERS-10 zeolite, to obtain a LHG fraction, a hydrotreating stage of this fraction LHR and the step of improving the quality of the resulting hydrotreated LRH by reaction with hydrogen in the presence of a catalytic system containing one or more metals selected and h Pt, Pd, Ir, Ru, Rh and Re, and acidic aluminosilicate.

The catalytic cracking stage in the fluidized bed of the catalyst according to the method of the present invention not only provides a higher conversion with respect to the results that can be achieved with conventional catalytic systems, but also provides optimal characteristics for the conversion of the heavier fraction (residues after cracking), expressed as the ratio of LHR and TWG (heavy recycle gas oil), with reduced production of TWG even up to 50% in relation to known methods.

The step of improving the quality according to the method of the present invention includes enrichment of the resulting mixture with alkylbenzene compounds, at least partially obtained from the conversion of naphtha-aromatic structures contained in the LHR fraction formed during the KKP stage, as well as during the hydrotreatment stage. The combined method of the present invention leads to hydrocarbon mixtures with an additionally improved cetane index and reduced density, the latter being comparable to that obtained by complete dearomatization, but with a much lower hydrogen consumption.

A particularly preferred aspect of the present invention is the implementation of the catalytic cracking stage in a fluidized bed of catalyst (CCP) under such conditions to obtain a high yield fraction of high-quality LHR in terms of density and nature of the aromatic compounds contained therein. In particular, in this case, the LHR fraction is characterized not only by high quality in terms of density, but also by an extremely preferred composition in terms of aromatic compounds, which makes it especially suitable for processing in the subsequent stages of the combined method according to the invention.

The content of polyaromatic compounds is actually lower with respect to LHR fractions obtained under normal conditions of CCP, while the content of benzonaphthenic compounds is higher. This preliminary enrichment with benzonaphthenic compounds simplifies the subsequent hydrotreatment and quality improvement stages, providing mixtures with optimal characteristics as fuel with a lower total hydrogen consumption compared to what is described in the prior art.

The mixture obtained at the KKP stage contains TWG as the main by-product, which can at least partially be recycled to the KKP stage, thus providing a higher overall yield of the obtained LHG.

In addition, by carrying out a catalytic cracking step in a fluidized catalyst bed in the presence of an ERS-10 containing catalyst, the conversion of the heavier fraction is increased, further increasing the overall LHR yield.

The purpose of the present invention is therefore associated with the integrated method of converting hydrocarbon fractions of petroleum origin into high-quality mixture of hydrocarbons as fuel, which includes the following stages:

- catalytic cracking of a hydrocarbon fraction in a fluidized bed of catalyst (KKP) in the presence of a zeolite-containing catalyst ERS-10, where the specified catalyst contains at least two components, to obtain a light recycle gas oil (LHG),

- hydrotreatment of light recycle gas oil,

- the interaction of hydrotreated light recycle gas oil obtained in the previous stage of hydrotreating with hydrogen in the presence of a catalytic system containing:

A1) one or more metals selected from Pt, Pd, Ir, Ru, Rh and Re,

b1) an acidic aluminosilicate selected from a zeolite belonging to the MTW family and a fully amorphous micromesoporous aluminosilicate having a molar ratio of SiO ₂ / Al ₂ O ₃ from 30 to 500, a surface area of more than 500 m ² / g, a pore volume of 0.3 up to 1.3 ml / g and an average pore diameter of less than 40 Å.

According to a particularly preferred aspect, the method of the present invention is carried out by the following steps:

(1) catalytic cracking of a hydrocarbon fraction of petroleum origin in a fluidized bed of catalyst (CCF) in the presence of a zeolite-containing ERS-10 catalyst, wherein said catalyst contains at least two components to produce a mixture containing LHG,

(2) separating the mixture obtained in the previous catalytic cracking step in the fluidized bed of the catalyst so as to separate at least the LHR fraction and the TEG fraction,

(3) re-feeding, if necessary, to the stage of catalytic cracking in the fluidized bed of the catalyst (CCP) at least part of the fraction of the TWG obtained in stage (2),

(4) hydrotreating the LHR fraction obtained in step (2),

(5) the interaction of the product obtained in the previous stage with hydrogen in the presence of a catalytic system containing:

A1) one or more metals selected from Pt, Pd, Ir, Ru, Rh and Re,

b1) an acidic aluminosilicate selected from a zeolite belonging to the MTW family and a fully amorphous micromesoporous aluminosilicate having a molar ratio of SiO ₂ / Al ₂ O ₃ from 30 to 500, a surface area of more than 500 m ² / g, a pore volume of 0.3 up to 1.3 ml / g and an average pore diameter of less than 40 Å.

The catalyst used in the first stage contains at least two different components: (a) a component containing one or more cracking catalysts, preferably catalytic cracking catalysts in a fluidized bed, and (b) a component containing ERS-10 zeolite.

Accordingly, in the first step of the combined process, the catalyst composition of the present invention can be used, comprising:

a) a first component containing one or more catalysts selected from zeolites, amorphous inorganic oxide cracking catalysts and inorganic oxide non-zeolite crystalline cracking catalysts,

b) a second component containing zeolite ERS-10.

In this catalyst, component (a) containing one or more catalytic cracking catalysts, preferably catalytic cracking in a fluidized catalyst bed, is combined with additive component (b).

Examples of amorphous materials that can be suitably used in component (a) as described in EP 1011291 are, for example, clay, aluminosilicate, magnesium silicate, zirconium silicate, titanosilicate, magnesium aluminum silicate, zirconium aluminum silicate, zirconium magnesium silicate.

The crystalline aluminosilicate described, for example, in US 4,309,279, can be used as a non-zeolite crystalline material in component (a).

A preferred aspect of the present invention is the use of zeolite as component (a), even more preferably large pore zeolite.

Zeolites that can be used for these purposes are zeolite Y (US 3130007), zeolite L (US 3126789), Omega zeolite (Cryst. Struct. Comm., 3, 339-344, 1974), Beta zeolite (US 3308069) and mordenite (Z. Kristallogr., 115, 439-450, 1961). Zeolite Y is preferably used. The same ERS-10 zeolite can be used in component (a) as a cracking catalyst in admixture with at least another cracking catalyst.

Suitable zeolites for use are zeolites ion exchanged with hydrogen and / or rare earth metal, or zeolites that have been heat treated using techniques well known to those skilled in the art.

Examples of zeolites that can usually be used as catalyst components are described in:

Paul B. Venuto, E. Thomas Habib, Jr., "Fluid Catalytic Cracking with Zeolite Catalysts", vol. 1, M. Dekker, Inc.,

Julius Scherzer, "Octane-Enhancing Zeolitic FCC Catalysts", M. Dekker, Inc.

Zeolites selected as component (a) can be used in bound form with a binder selected, for example, from silica, alumina, silica-alumina, clay, zirconium silicate, magnesium silicate, aluminum phosphate, or mixtures thereof. The preparation of the bound form of zeolite is carried out according to technologies known to specialists in this field.

Component (b) of the catalyst composition of the present invention contains an ERS-10 zeolite, wherein said zeolite acts as an additive.

This zeolite was first described in EP 796821, and is also well described in:

- S. Zanardi, G, Cruciani, L. G. Carluccio, G. Bellussi, C. Perego, R. Millini, "Framework topology of ERS-10 zeolite", Angew. Chem. Int. Ed., 41 (21), 2002, 4109-4112.

- C. Perego, M. Margotti, L. G. Carluccio, L. Zanibelli, G. Bellussi, "The catalytic performances of zeolite ERS-10", Stud. Surf Sci. Catal., 135, 2001, 29 O 01.

- S. Zanardi, G, Cruciani, LG Carluccio, G. Bellussi, C. Perego, R. Millini, "Synthesis and framework topology of the new disordered ERS-10 zeolite", J. Porous Mater., 14, 2007, 315 -323.

The preparation of zeolite ERS-10 is well described in EP 796821. The synthesis is preferably carried out by heating the reaction mixture containing 6-azonium-spiro [5.5] -undecane (Q) hydroxide as an organic additive, tetraethylorthosilicate (TEOS) and aluminum isopropoxide ( IPA) as sources of silicon dioxide and aluminum, respectively, sodium hydroxide (NaOH) and water, preferably in the following molar ratios:

SiO ₂ / Al ₂ O ₃ from 50/1 to infinity Na ⁺ / SiO ₂ from 0.05 / 1 to 0.15 / 1 Q / SiO ₂ from 0.2 / 1 to 0.3 / 1 H ₂ O / SiO ₂ from 40/1 to 50/1 OH ^- / SiO ₂ from 0.25 / 1 to 0.45 / 1

in the temperature range from 150 to 180 ° C, preferably from 155 to 170 ° C for 7-28 days, preferably for 7-14 days at autogenous pressure in a stainless steel autoclave.

The resulting crystalline material is dried at a maximum temperature of 170 ° C, preferably at a temperature of from 90 to 120 ° C, and calcined at a temperature of from 500 to 700 ° C, preferably from 550 to 650 ° C, for a period of time ranging from 4 to 20 hours, preferably from 6 to 15 hours.

From the structural point of view, it was experimentally shown that the aluminosilicate lattice of ERS-10 is disordered and can be described as the germination of three structurally interconnected zeolites: non-force (NON, a zeolite of the type clathrasil, which is characterized by the presence of only frameworks that are not connected to the outer side of the crystal) , EU-1 (EUO, a medium sized pore zeolite with a one-dimensional channel system with holes containing 10 tetrahedrons (10-membered ring) with large side pockets) and Nu-87 (NES, a zeolite with pores with ednego size, which is characterized by one-dimensional system of channels with openings comprising 10 tetrahedra (10-membered ring)). In more detail, the ERS-10 structure can be constructed using two periodic blocks (known as periodic building blocks, PSB). A random combination of these periodic blocks leads to the formation within the zeolite crystal of regions possessing the characteristics of the three zeolites mentioned above (NON, EUO and NES), in addition to the presence of additional structures, which are characterized by the presence of pores with holes containing 14 tetrahedra (14-membered ring) . Therefore, the characteristics common to zeolites with medium-sized pores (10-membered ring) and zeolites with extra-large pores (14-membered ring) coexist in the same structure.

Zeolite ERS-10 crystallizes in pure form from a mixture of reagents with a molar ratio of SiO ₂ / Al ₂ O ₃ (OKA) in the range from 80 to 160, which is therefore preferred.

Crystalline products are subjected to Al enrichment to OKA values ranging from 60 to 80: by using reaction mixtures having OKA values <80, co-crystallization of mordenite (MOR) can be obtained.

With OKA values> 160, zeolite ZSM-12 (MTW) can form.

Since ERS-10 zeolite is the result of the germination of various zeolite phases, this implies the variability of their relative ratio, or, from a technical point of view, the probability of stacking periodic blocks. This leads to the possibility of obtaining products having different characteristics in terms of the relative content of the regions corresponding to the three structures of NON, EDO and NES and channels with holes formed by 14-membered rings.

When using ERS-10 zeolite as a component of a new catalytic composition for cracking hydrocarbon mixtures, in particular KKP, the fact that it is the result of the germination of various phases with a variable ratio does not affect its catalytic characteristics, since they are not even affected by the presence of a small amount of mordenite or zeolite ZSM-12, possibly formed during the synthesis of zeolite ERS-10, preferably in an amount not exceeding 30 mass. % relative to the mass of zeolite ERS-10. The possible formation of additional phases of zeolites NON, EUO and NES in small quantities, preferably not higher than 30 mass. % in relation to the mass of zeolite ERS-10, does not significantly affect the characteristics of the catalyst.

When used as an additive for CCP according to the combined method of the present invention, ERS-10 can be used in various related forms prepared in accordance with techniques known to those skilled in the art, such as, for example, granules or, preferably, microspheres. Microspheres containing zeolite in bound form can be prepared by spray drying using known techniques. Silica, amorphous aluminosilicate, alumina or mixtures thereof can preferably be used as binders.

In component (b), the zeolite in the bonded form using a binder is preferably from 5 to 90 mass. % relative to the total weight of the specified component.

In the composition of the present invention, zeolite ERS-10 is preferably present in an amount of from 1 to 10 mass. % relative to the weight of the catalyst contained in component (a).

The catalytic composition used in the catalytic cracking stage in the fluidized bed of the catalyst can be prepared:

- by mechanically mixing component (a) and (b) according to technologies known to those skilled in the art, in which case ERS-10 zeolite is a component of catalytic particles physically different from particles containing a catalyst of component (a),

- by simultaneous binding according to known technologies of ERS-10 zeolite and the catalyst contained in component (a), in which case ERS-10 zeolite and the catalyst are contained in the same particle of the catalyst composition,

- in situ, by adding component (b) to component (a) already present in the cracking method, at any point in this method.

The use of zeolite ERS-10 as an additive for cracking, preferably for catalytic cracking in a fluidized bed of catalyst, provides a higher conversion of raw materials KKP and, in particular, high cracking of the lower fractions with the predominant formation of the fraction of LHG and diesel fuel in relation to the formation of the fraction of TEG .

Hydrocarbon mixtures suitable for processing according to the method of the present invention are, for example, gas oils, oil fractions containing VGO (vacuum gas oils) having a boiling point of 350 to 550 ° C., atmospheric residues, deasphalted oils, thermal cracking products and hydrocracking residues . The products obtained from the combined method of catalytic cracking in a moving catalyst bed of the present invention are listed below: fuel gas (H2, C1-C2), LPG (liquefied petroleum gas; C3-C4), gasoline (C5-221 ° C), LHG (221-350 ° С), ТРГ (350 + ° С).

The CCP step can be performed according to conditions known to those skilled in the art and described, for example, in the Fluid Catalytic Cracking Handbook, 2 ^nd edition, Reza Sadeghbeigi, ed. Gulf Professional Publishing, 2000.

The method of catalytic cracking in a fluidized bed of a catalyst is generally divided into two stages: cracking carried out in a separation column and reduction of a catalyst carried out in a regenerator, both stages being performed with a catalyst in a fluidized phase.

The cracking reaction is substantially endothermic, supported by physical heat captured by the stream of reduced catalyst, and it proceeds by contacting the hydrocarbon feed with the hot reduced catalyst.

The reaction conditions of the catalytic cracking in the fluidized bed of the catalyst include a temperature in the range from 400 to 650 ° C, preferably from 450 to 650 ° C. The pressure in the reaction zone is from 100 to 500 kPa (from 1 to 5 bar), preferably from 130 to 450 kPa (from 1.3 to 4.5 bar). The catalyst / oil ratio is from 1 to 10 kg / kg, the vapor residence time in the reaction region is from 0.5 to 10 seconds, preferably from 1 to 5 seconds.

The recovery of the depleted cracking catalyst proceeds by burning oxygen in the coke deposited on the catalyst at a temperature of from 600 to 815 ° C and a regenerator pressure of 130 to 450 kPa (1.3 to 4.5 kg / cm ² ), preferably from 240 to 400 kPa (2.4 to 4.0 bar).

The catalytic cracking step in the fluidized bed of the catalyst can operate continuously or batchwise, with a fixed bed, a moving bed or a fluidized bed. The hydrocarbon mixture stream can be fed either in stream or in countercurrent with respect to the catalyst stream.

According to a particularly preferred aspect of the present invention, the catalytic cracking stage in the fluidized bed of the catalyst is carried out under such conditions as to obtain an LHR fraction having an additionally improved quality in terms of density and characterized by a particularly preferred composition in terms of aromatic compounds. Essentially, the content of polyaromatic compounds is reduced in comparison with fractions of LHR obtained under normal CKP conditions, while the content of benzonaphthenic compounds is increased.

This characteristic of the composition simplifies the subsequent stages of hydrotreating and improving quality, making it possible to obtain mixtures as fuel with optimal characteristics, consuming less hydrogen compared to what is described in the prior art. According to this preferred aspect of the present patent application, the high LHR yields obtained at the CCP stage are achieved by selecting specific and specific temperature conditions and / or by selecting specific temperatures for preheating the feedstock. The selection of these special conditions for the implementation of the catalytic cracking stage in the fluidized bed of the catalyst also makes it possible to direct the cracking reaction towards a higher TWH formation as a reaction by-product, which can be recycled to the KKP stage, ensuring a higher overall LHG yield.

Special and selected temperature conditions that allow to maximize the formation of LHR range from 490 to 530 ° C.

Special temperatures of preheating of raw materials, which allow to maximize LHG output, range from 240 to 350 ° C.

In both cases, it is preferable to operate at a pressure of 200 to 350 kPa (2.0 to 3.5 bar).

As for the remaining parameters of the method, you can select the conditions usually used by specialists in this field.

Carrying out the KKP stage so that at least one of the preceding conditions for the temperature and the temperature of the preheating is satisfied, an increase in the LHG yield is obtained by at least 50%, and the addition of up to 100% consists of:

- fuel gas (H2, C1, C2)

- CIS (C3-C4)

-gasolines (С5-210 ° С)

- TWG (370+ ° C)

- coke.

As for stage (a), carried out in the presence of a zeolite-containing ERS-10 catalyst, the above process conditions associated with the temperature and / or temperature of the preheating of the feedstock, which allow to maximize the formation of LHR and obtain a fraction of LHR with high quality with respect to density aromatic compounds are new and represent an additional aspect of the present invention.

The mixture obtained in the first step of the combined process of the present invention is separated, preferably by distillation.

The TRH fraction obtained by separation is preferably recycled to the KKP stage, for example, in a mixture with raw materials.

The LHR fraction obtained by separation, which is characterized by a composition rich in benzonaphthenic compounds in terms of the content of aromatic compounds, is subjected to hydrotreating in order to reduce the nitrogen and sulfur contents and change the composition of the fraction, further enriching it with benzonaphthenic compounds.

Hydrotreating of the LHR fraction is carried out in one or more fixed bed reactors, and the catalytic layers may contain the same or different catalysts. Typically, catalysts based on Group VI and / or Group VIII metal compounds on a support, preferably an amorphous support, such as, for example, alumina or aluminosilicate, are selected. Metals that can be suitably used are, for example, nickel, cobalt, molybdenum and tungsten. Examples of selectable catalysts and their preparation are described in Hydrocracking Science and Technology, J. Scherzer and AJ Gruia, Marcel Dekker, 1996. Hydrotreating is described, for example, in Catalysis Science and Technology, ed. by R. Anderson and M. Boudart, vol. 11, Springer Verlag, 1996. Hydrotreating catalysts are used in sulfidized form. Sulphidation can be obtained, for example, by directing to the catalyst a suitable feedstock containing sulfur compounds such as dimethyl disulfide (DMDS), dimethyl sulfoxide (DMSO) or other compounds that upon decomposition cause H ₂ S.

Hydrotreating is preferably carried out at a temperature of from 200 to 400 ° C, even more preferably at a temperature of from 330 to 380 ° C. Typically, the pressure is from 2 MPa to 10 MPa (20 to 100 bar), preferably from 4 MPa to 8 MPa (40 to 80 bar). The LHSV space velocity is preferably from 0.3 to 3 h ^-1 . The ratio of H ₂ / feed is preferably from 200 to 2000 standards. l / l During hydrotreating, LRG feedstock undergoes saturation reactions of aromatic rings with a decrease in the content of aromatic carbon and enrichment with naphthoaromatic compounds.

The next quality improvement step is carried out in accordance with WO 2007/006473 in the presence of a bifunctional catalyst system containing one or more metals selected from Pt, Pd, Ir, Ru, Rh and Re and an acidic aluminosilicate selected from a micromesoporous aluminosilicate having a suitable composition, and zeolite belonging to the MTW family.

This stage of the method leads to a significant improvement in the characteristics of hydrotreated LRH, in particular, in terms of cetane index (number), density and distillation curve, which are equivalent to the characteristics obtained by simple hydrogenation of aromatic structures. At this stage, a slight formation of low molecular weight products is detected and lower hydrogen consumption is required compared to known methods.

This stage is carried out in the presence of hydrogen with a catalytic system containing:

A1) one or more metals selected from Pt, Pd, Ir, Ru, Rh and Re,

b1) an acidic aluminosilicate selected from a zeolite belonging to the MTW family and a fully amorphous micromesoporous aluminosilicate having a molar ratio of SiO ₂ / Al ₂ O ₃ from 30 to 500, a surface area of more than 500 m ² / g, a pore volume of 0.3 up to 1.3 ml / g and an average pore diameter of less than 40 A.

This stage of the method allows to significantly increase the cetane index (number) together with a decrease in the density and T95 of the hydrotreated LRH mixture. The LRH mixture thus obtained is, among other things, additionally enriched in alkylbenzene compounds, which are, at least in part, obtained from partially hydrogenated polycyclic aromatic compounds of the benzonaphthenic type, either already present in the LRH fraction obtained from a special CCP stage of the present combined process, or during hydrotreatment.

The catalyst used at this stage of the process promotes the formation of alkylbenzene structures by hydrodecyclization of the naphthenic ring of naphtabenzene or dinaptabenzene structures, thereby obtaining the best possible compromise between hydrogen consumption and improving product characteristics, while limiting both the complete hydrogenation reaction of aromatic rings and the cracking reaction for the formation of light products.

The catalysts used are described in patent application WO 2007/006473. The acid component (b1) of the catalyst composition used in the present invention can be selected from MTW type zeolites: the MTW family is described in Atlas of zeolite structure types, WW Meier and DHOlson, 1987, Butterworths. The zeolite of the structural type MTW, which is suitable for use in the present invention, is an aluminosilicate with a SiO ₂ / Al ₂ O ₃ molar ratio of greater than or equal to 20. This zeolite and its preparation are described in A. Katovic and G. Giordano, Chem. Ind. (Dekker), Synthesis of Porous Materials, 1997, 69, 127-137. According to a preferred aspect, zeolite ZSM-12 is used, described in US 3,832,449 and Ernst et al., Zeolites, 1987, vol. September 7th.

In preparing the catalyst composition, the zeolite is used in its acid form.

If the acid component (b1) is an aluminosilicate, in a preferred aspect, the molar ratio of SiO ₂ / Al ₂ O ₃ is from 50 to 300. According to another preferred aspect, the porosity of the aluminosilicate is from 0.4 to 0.5 ml / g.

The completely amorphous micromesoporous aluminosilicates that can be used in the quality improvement step of the present invention are called MSA, and their preparation is described in US 5049536, EP 659478, EP 812804. Their powder X-ray diffraction spectrum does not correspond to the crystal structure and does not show any peak .

Catalytic compositions that can be used in the quality improvement step of the present invention, in which the acid component is an MSA type aluminosilicate, are described in EP 582347.

Aluminosilicates that can be used in the step of improving the quality of the method of the present invention can be prepared according to EP 659478, starting from tetraalkylammonium hydroxide, aluminum compound hydrolyzable in Al ₂ O ₃ , and silicon compound hydrolyzable in SiO ₂ , wherein said tetraalkyl ammonium hydroxide is a hydroxide tetra (C ₂ -C ₆ ) alkylammonium, said hydrolyzable aluminum compound is tri (C ₂ -C ₄ ) alkoxide and said hydrolyzable silicon compound is tetra (C ₁ -C ₅ ) alkyl orthosilicate: these reagents they undergo hydrolysis and gelification, operating at a temperature equal to or higher than the boiling point, at atmospheric pressure, of any alcohol that is obtained as a by-product of this hydrolysis reaction, without or without substantial removal of these alcohols from the surrounding reaction medium.

The gel thus obtained is dried and calcined, preferably in an oxidizing atmosphere, at a temperature of from 500 to 700 ° C. for 6-10 hours.

This procedure involves the preparation of an aqueous solution of tetraalkylammonium hydroxide and aluminum trialkoxide, and tetraalkylorthosilicate is added to this aqueous solution, operating at a temperature below the hydrolysis temperature, with quantities of reagents that are such as to provide a molar ratio of SiO ₂ / Al ₂ O ₃ of 30/1 up to 500/1, tetraalkylammonium hydroxide / SiO ₂ from 0.05 / 1 to 0.2 / 1 and H ₂ O / SiO ₂ from 5/1 to 40/1, and hydrolysis and gelation are started by heating to a temperature of from about 65 up to approximately 110 ° C, operating in an autoclave at autogenous pressure and the system or at atmospheric pressure in a reactor equipped with a condenser.

As for the metal component of the catalyst compositions used in the quality improvement step of the present invention, they are selected from Pt, Pd, Ir, Ru, Rh, Re and mixtures thereof. According to a particularly preferred aspect of the present invention, the metal is platinum, iridium, or a mixture thereof.

The amount of metal or mixture of metals is preferably from 0.1 to 5 mass. % relative to the total weight of the catalyst composition, and preferably is from 0.3 to 1.5 mass. %

Mass fraction of metal or metals refers to the metal content, expressed as the elemental metal content, in the final catalyst, after calcination, said metal is in the form of oxide.

Before being used in the quality improvement step, the catalyst is activated by known techniques, for example by reduction treatment, and preferably by drying and subsequent reduction. Drying is carried out in an inert atmosphere at temperatures from 25 to 100 ° C, while reduction is obtained by heat treatment of the catalyst in a reducing atmosphere (N ₂ ) at a temperature of from 300 to 450 ° C and a pressure of preferably from 100 kPa to 5 MPa (from 1 to 50 atm.).

The acid component (b1) of the catalyst, which is used in the step of improving the quality of the method of the present invention, can be in extruded form with conventional binders, such as, for example, alumina, boehmite or pseudoboehmite. The extruded product can be prepared according to a technique well known to those skilled in the art. The acid component (b1) and the binder can be pre-mixed in mass ratios from 30:70 to 90:10, preferably from 50:50 to 70:30. At the end of mixing, the resulting product is compacted into the final desired form, for example in the form of extruded granules or tablets. Alternatively, if component (b1) is an aluminosilicate, an extruded catalyst prepared as described in EP 665055 can be used as the extruded component (b1).

As for the metal phase (a1) of the catalyst, the quality improvement step can be introduced by impregnation or ion exchange. According to the aforementioned technology, the acid component (b1), also in extruded form, is moistened with an aqueous solution of a metal compound, acting, for example, at room temperature and a pH of from 1 to 4. The resulting product is dried, preferably in air, at room temperature, and fired in oxidizing atmosphere at a temperature of 200 to 600 ° C.

In the case of impregnation with alcohol, the acid component (b1) is suspended in a metal-containing alcohol solution. After impregnation, the solid is dried and calcined.

According to ion exchange technology, the acid component (b1) is suspended in an aqueous solution of a metal complex or a metal salt, acting at room temperature and pH from 6 to 10. After ion exchange, the solid is separated, washed with water, dried and finally thermally treated in an inert or oxidizing atmosphere . Temperatures that can be used for this purpose range from 200 to 600 ° C.

The metal compounds that can be used in the above preparation methods are H ₂ PtCl ₆ , Pt (NH ₃ ) ₄ (OH) ₂ , Pt (NH ₃ ) ₄ Cl ₂ , Pd (NH ₃ ) ₄ (OH) ₂ , PdCl ₂ , H ₂ IrCl ₆ , RuCl ₃ , RhCl ₃ .

The step of improving the quality of the method of the present invention is preferably carried out at a temperature of from 240 to 380 ° C, at a pressure of from 1 to 10 MPa (10 to 100 atm.), MCHOS from 0.5 to 5 h ^-1 and with the ratio of hydrogen to feed (Н ₂ / НС) from 400 to 2000 normal l / kg (Nlt / kg). It is preferable to operate at a pressure above 2 MPa (20 atm.) And below or equal to 8 MPa (80 atm.), While the temperature is preferably from 250 to 330 ° C, if the acidic component (61) is a MTW zeolite, and is preferably from 300 to 380 ° C, if the acid component (61) is an aluminosilicate.

Example

The tests were carried out using a fixed-bed microreactor, which is a quartz reactor placed in a furnace. Various amounts of a commercially available catalyst belonging to the class of zeolite systems and containing, in particular, zeolite Y as the active phase, were loaded into the reactor while maintaining a balance (according to the ratio of catalyst / required charge, indicated as Cat / Oil), diluted with quartz microspheres and preheated in a stream of nitrogen. The download, the characteristics of which are shown below in table 1, was filed with an adjustable speed.

Table 1 Density at 15 ° C, kg / l 0,9003 Refractive Index at 75 ° C 1.4810 Sulfur,% 0.45 ASTM-D 6352 [° C] TNC / 5% 218/305 10% / 30% 341/410 50% / 70% 454/507 90% / TKK 602/713 Nitrogen,% 0.14

Operating conditions are shown in the following table.

Reaction temperature, ° C 560 Loading (Oil), g 1,5 Injection time, s 12

The characteristics of ERS-10 as an additive were evaluated by mixing 3.0% of the mass. ERS-10 with catalysts while maintaining balance and comparing with the catalyst as such.

- Base case: commercially available catalyst based on zeolite Y and loading according to table 1.

- Example with ERS-10: base case + 3.0% ERS-10.

The table below shows the results, expressed in terms of conversion, comparing the base case with the case in which ERS-10 was added, when working with a cat./oil ratio (2.0) and T of 560 ° C:

Base case Example with ERS-10 Cat / Oil 2 2 Conversion 60.8 71.2 Fuel gas 2.2 2,4 CIS 17.4 19.1 Petrol 37.1 45,2 LRH (370-) 21.6 18.3 TWG (370+) 17.5 10,4 Coke 4.0 4.4 Cracked Residues 1,2 1.8

As can be seen from the table, the addition of ERS-10 as an additive contributes to a noticeable increase in conversion and a significant increase in residues after cracking, i.e. relation between LRH and TWG. The indicated greater amount of LHG is then used in the subsequent stage of quality improvement.

Claims (21)

1. The combined method of converting hydrocarbon fractions of petroleum origin into high-quality mixture of hydrocarbons as fuel, which includes the following stages:
- catalytic cracking of a hydrocarbon fraction in a fluidized bed of catalyst (CCF) at a temperature of from 400 to 650 ° C and at a pressure of from 100 to 500 kPa (1 to 5 bar) in the presence of a zeolite-containing ERS-10 catalyst, wherein said catalyst contains at least at least two components, where these components are:
(a) a component containing one or more catalytic cracking catalysts in a fluidized bed, and
(b) a component containing zeolite ERS-10,
to obtain light recycle gas oil (LHG),
- hydrotreatment of light recycle gas oil,
- the interaction of hydrotreated light recycle gas oil obtained in the previous hydrotreatment stage, with hydrogen in the presence of a catalytic system containing:
a1) one or more metals selected from Pt, Pd, Ir, Ru, Rh and Re,
b1) an acidic aluminosilicate selected from a zeolite belonging to the MTW family and a fully amorphous micromesoporous aluminosilicate having a molar ratio of SiO ₂ / Al ₂ O ₃ from 30 to 500, a surface area of more than 500 m ² / g, a pore volume of 0.3 up to 1.3 ml / g and an average pore diameter of less than 40 Å. 2. The method according to claim 1, comprising the following stages:
(1) catalytic cracking of a hydrocarbon fraction of petroleum origin in a fluidized bed of catalyst (CCF) in the presence of a zeolite-containing ERS-10 catalyst, wherein said catalyst contains at least two components to obtain a mixture containing LHG,
(2) the separation of the mixture obtained in the previous stage of catalytic cracking in the fluidized bed of the catalyst, so as to separate at least the LHG fraction and the TEG fraction,
(3) if necessary, re-supplying at least a portion of the TWG fraction obtained in step (2) to the step (1) of catalytic cracking in a fluidized bed of catalyst,
(4) hydrotreating the LHR fraction obtained in step (2),
(5) the interaction of the product obtained in the previous stage with hydrogen in the presence of a catalytic system containing:
A1) one or more metals selected from Pt, Pd, Ir, Ru, Rh and Re,
b1) an acidic aluminosilicate selected from a zeolite belonging to the MTW family and a fully amorphous micromesoporous aluminosilicate having a molar ratio of SiO ₂ / Al ₂ O ₃ from 30 to 500, a surface area of more than 500 m ² / g, a pore volume of 0.3 up to 1.3 ml / g and an average pore diameter of less than 40 Å. 3. The method according to claim 2, in which the catalyst used in the first stage includes:
a) a first component containing one or more catalysts selected from zeolites, amorphous inorganic oxide cracking catalysts and inorganic oxide non-zeolite crystalline cracking catalysts,
b) a second component containing zeolite ERS-10. 4. The method according to claim 3, in which in component (a) the zeolites are zeolites with large pores. 5. The method according to claim 4, in which in component (a) the zeolite is zeolite Y. 6. The method according to claims 1 or 2, in which at the first stage the zeolite ERS-10 is crystallized together with mordenite or zeolite ZSM-12. 7. The method according to claims 1 or 2, in which at the first stage the ERS-10 zeolite contains auxiliary phases of zeolites NON, EUO and NES. 8. The method according to claims 1 or 2, in which at the first stage the zeolite ERS-10 is used in bound form. 9. The method according to claim 1, in which in component (b) the zeolite ERS-10 is present in an amount of from 1 to 10% relative to the weight of the catalyst contained in component (a). 10. The method according to claims 1 or 2, in which in the first stage of catalytic cracking in a fluidized bed of a catalyst, the catalyst composition is prepared by a method selected from:
- mechanical mixing of components (a) and (b) according to technologies known to a person skilled in the art, in which case ERS-10 zeolite is a component of catalytic particles physically different from particles containing a catalyst of component (a),
- performed simultaneously binding ERS-10 zeolite and the catalyst contained in component (a),
- in situ mixing, performed by adding component (b) to component (a) already present in the catalytic cracking method in the fluidized bed of the catalyst, at any point in the method itself. 11. The method according to claims 1 or 2, in which the first stage of catalytic cracking in the fluidized bed of the catalyst is performed at a temperature of from 400 to 650 ° C. 12. The method according to claims 1 or 2, in which the first stage of catalytic cracking in the fluidized bed of the catalyst is performed at a pressure of from 100 to 500 kPa (1 to 5 bar). 13. The method according to claims 1 or 2, in which the mixture of hydrocarbons processed in the first stage are gas oils, oil fractions consisting of VGO (vacuum gas oil) having a boiling point of 350 to 550 ° C, atmospheric residues, deasphalted oils , thermal cracking products and hydrocracking residues. 14. The method according to claims 1 or 2, in which the temperature at which the first stage is performed is from 490 to 530 ° C. 15. The method according to claims 1 or 2, in which at the first stage use the temperature of the preheating of the feed substance from 240 to 350 ° C. 16. The method according to claims 1 or 2, in which the stage of hydrotreating is performed at a temperature of from 200 to 400 ° C and a pressure of from 2 to 10 MPa (from 20 to 100 bar). 17. The method according to claims 1 or 2, in which at the stage of improving the quality of the metal component (A1) is selected from platinum, iridium or mixtures thereof. 18. The method according to claims 1 or 2, in which the stage of improving the quality is carried out at a temperature of from 240 to 380 ° C and a pressure of from 1 to 10 MPa (from 10 to 100 atm.), MCHOS from 0.5 to 5 h ^-1 and with a ratio of hydrogen to feed (H ₂ / HC) from 400 to 2000 norms. l / kg 19. The method of catalytic cracking in a fluidized bed of a catalyst for the conversion of hydrocarbon fractions of petroleum origin into mixtures containing LHG, performed at a temperature of from 490 to 530 ° C in the presence of a catalyst containing zeolite ERS-10, wherein said catalyst contains at least two components. 20. The stage of catalytic cracking in a fluidized bed of a catalyst for the conversion of hydrocarbon fractions of petroleum origin into mixtures containing LHG, performed in the presence of a catalyst containing zeolite ERS-10, wherein said catalyst contains at least two components at which the preheating temperature of the feed substance is from 240 to 350 ° C. 21. The method according to PP.19 and 20, performed in the presence of a catalyst containing zeolite ERS-10, and the specified catalyst contains at least two components and the specified method is performed at a temperature of from 490 to 530 ° C with a temperature of preheating of the feed material from 240 up to 350 ° C.