WO2018052341A1

WO2018052341A1 - Catalyst for n-alkane isomerisation during reforming of hydrotreated gasoline fractions (variants)

Info

Publication number: WO2018052341A1
Application number: PCT/RU2017/000666
Authority: WO
Inventors: Вадим Владимирович ФАДЕЕВ; Анна Всеволодовна АБРАМОВА; Денис Николаевич ГЕРАСИМОВ; Левон Львович ХЕМЧЯН; Анна Николаевна ЛОГИНОВА; Денис Владимирович ЛЯМИН; Екатерина Григорьевна ПЕТРОВА; Надежда Юрьевна УВАРОВА; Роман Алексеевич СМОЛИН
Original assignee: Публичное акционерное общество "Нефтяная компания "Роснефть" (ПАО "НК "Роснефть")
Priority date: 2016-09-16
Filing date: 2017-09-13
Publication date: 2018-03-22
Also published as: RU2626747C1

Abstract

The group of inventions relates to a catalyst for n-alkane isomerisation during reforming of hydrotreated gasoline fractions. According to a first variant, the catalyst comprises, in wt.%: 0.1-0.3 platinum, 0.07-0.30 tin, and 10-60 silicoaluminophosphate zeolite SAPO-31 or silicoaluminophosphate zeolite SAPO-11, with the remainder being aluminium oxide. In a particular embodiment, the catalyst also contains an FAU structure zeolite in an amount of 10.0-60.0 wt.%, where the FAU structure zeolite is an aluminosilicate USY in the H+ form with an SiO₂/Al₂O₃ molar ratio of 82.6. According to a second variant the catalyst comprises, in wt.%, 0.1-0.3 platinum and 10.0-60.0 a mixture of silicoaluminophosphate zeolite SAPO-31 and silicoaluminophosphate zeolite SAPO-11, with the remainder being aluminium oxide. In a particular embodiment, the catalyst also contains an FAU structure zeolite in an amount of 10.0-60.0 wt.%, where the FAU structure zeolite is an aluminosilicate USY in the H+ form with an SiO₂/Al₂O₃ molar ratio of 82.6, as well as tin in an amount of 0.1-0.30 wt.%. The invention makes it possible for n-alkane isomerisation to be performed effectively when reforming hydrotreated gasoline fractions, providing for an isoalkane formation selectivity of at least 92.0 wt.% and increased isoalkane content in the reformate (stable catalysate) of at least 14.0 wt.% relative to the feedstock.

Description

The catalyst for the isomerization of n-alkanes in the process of reforming hydrotreated gasoline fractions (options)

Technical field

The invention relates to the field of catalysis and oil refining, in particular, to a catalyst based on silicoaluminophosphate zeolites of the ATO and / or AEL structure, which efficiently provides isomerization of normal alkanes in the process of reforming hydrotreated gasoline fractions, and a method for its preparation. State of the art

The long-term prospects for the development of the oil refining industry are inevitably associated with the introduction of new technologies for the deep processing of oil that fully meet the strict economic, environmental and quality standards of the produced motor fuels. The potential progress in this area, of course, lies in the industrial implementation of catalytic processes, among which reforming is the leading value - large-capacity production of high-octane gasolines.

Despite a number of important long-term achievements in the development and study of catalysts, today there is still no complete unambiguous idea of the mechanism of all transformations that occur during the reforming process, and therefore there is no single idea of the optimal composition of reforming catalysts. This situation is primarily due to the fact that reforming is a complex set of both targeted and secondary heterogeneous catalytic reactions. In particular, the target reactions include: dehydrogenation of naphthenic hydrocarbons ^~ to arenas, ^" isomerization of five-membered cycloalkanes to cyclohexane derivatives, isomerization of n-alkanes to iso-alkanes, dehydrocyclization of alkanes to naphthenic and aromatic hydrocarbons, dehydrogenation of alkanes to hydroxy alkanes; as well as condensation reactions leading to coke deposition on the catalyst.

Current trends in the design of catalytic systems for the industrial implementation of the reforming process are aimed at creating catalysts with a certain set of specified properties that will allow to obtain reformate with the necessary operational and environmental characteristics (knock resistance, fractional composition, etc.), at lower temperatures without reducing yield. The properties of the catalyst, in turn, are determined by its composition. However, the development of the composition of the catalyst is complicated by the complex, as noted above, complex picture of the chemistry of the reforming process. In this connection, it seems appropriate to select the optimal catalyst composition for each individual type of target transformations (dehydrogenation, isomerization, dehydrocyclization).

Isomerization of n-alkanes to iso-alkanes does not lead to the formation of aromatic hydrocarbons. At the same time, the detonation resistance of the obtained reformate increases, which is due to higher octane numbers of the formed branched hydrocarbons (iso-alkanes) compared to hydrocarbons of a normal structure (n-alkanes) contained in the initial gasoline fractions. Despite the lower detonation resistance of iso-alkanes relative to aromatic hydrocarbons, an increase in the proportion of isomerization among target transformations during reforming is of exceptional importance from the point of view of complying with current environmental standards that strictly regulate the need to reduce the content of aromatic hydrocarbons (in particular benzene and its derivatives) in commercially available gasolines.

In this regard, the creation of a catalyst with increased isomerizing activity for the reforming process is one of the urgent tasks facing the further development of the modern oil refining industry.

Currently used industrial catalysts for the isomerization of the C5-C6 hydrocarbon fraction, in general, can be classified as follows:

- fluorinated aluminoplatinum ~ catalysts: predominantly high-temperature isomerization (up to 440 ° С),

- zeolite catalysts: mainly medium temperature isomerization (250-300 ° C),

- chlorine promoted alumina, sulfated metal oxides such as tungsten, zirconium, etc.: predominantly low-temperature isomerization (<200 ° C). Among the above, fluorinated aluminoplatinum catalysts are characterized by an undesirably high operating temperature range, which inevitably leads to an increase in energy costs.

Chlorinated alumina catalysts have a low operating temperature range, providing a high yield of isomerizate, however, during isomerization, the chlorine content in these catalysts decreases, which quickly leads to a significant decrease in activity. In this regard, the introduction of chlorine-containing compounds (usually CC) into the processed feed is provided to maintain a high activity of the catalyst, which, in turn, necessitates the further capture of chlorine derivatives (alkaline washing). Along with this, a significant drawback of this type of catalyst is also its extreme sensitivity to catalytic poisons and moisture, which inevitably accelerates their deactivation.

Zeolite catalysts have a relatively low operating temperature range, while differing in their exceptional resistance to poisonous impurities in raw materials and the ability to fully regenerate, thereby presenting a favorable compromise between alumina-platinum fluorinated catalysts and chlorinated alumina catalysts.

The uniqueness of zeolites lies in a comprehensive set of properties: acidity, porosity, structure of the crystal lattice, sorption ability, the possibility of ion exchange, etc. Directional changes in certain properties, combined with a variation in the percentage of zeolite, make it possible to create catalysts with high activity and selectivity in reactions of one type or another in combination with good stability. Thus, zeolites serve as an additional effective tool in the production of catalysts used in the oil refining industry. Literary examples of zeolite isomerization catalysts are presented by a number of systems, overwhelmingly, based on various aluminosilicates. Separate representative examples are provided below.

The catalyst composition mordeniteL (0.5 - 1.5 Macc%) / Zn (0.5 - 1.5 mass%) was used in the process of isomerization of n-butane at a temperature of 550 ° C. The achieved conversion was in a satisfactory range of 45 - 48%, however, the selectivity was low: the content (mol%) of isobutane in the resulting product mixture was about 17.0, while the content of the products of the cracking side reactions (Q + C2 + C3) is 33.0. US 5658839 A, 08.19.1997.

Relatively low conversion, low selectivity, undesirably high platinum content and high process temperature (550 ° C) are obvious disadvantages of this catalyst.

The isomerization catalyst based on mordenite of the general composition A1 ₂ Oz eolite (59-60 mass%) / P1 (0.1-1.0 Macc%) Pd (0-1.0 mass%) was studied in the process of isomerization of n-hexane ( 310 ° C, 20 atm). The catalyst allowed to achieve 20.0 - 36.9 mass% of the conversion of n-hexane with high selectivity: the total yield of iso-hexanes was 19.8 mass% for the conversion of n-hexane 20.0 mass% and 36.5 mass% for the conversion of n -hexane 36.9 mass%. It should be noted that high selectivity was observed both in the presence of palladium in the composition of the catalyst and without the use of palladium; however, the presence of palladium was a necessary condition for increasing the conversion of n-hexane. Without the use of palladium, the conversion of n-hexane did not exceed 20.0 mass%. This catalyst was also used in the process of hydroisomerization (310 ° C, 20 atm) of the gasoline fraction of catalytic cracking, having OCH = 69 and containing 23.9 mass% of iso-paraffins. Catalyst A1 ₂ Oz eolite (59.8 mass%) LF (0.3 mass%) led to an increase in the content of iso-paraffins by 13.3 mass%, an increase in the GPI by 6.5 points; catalyst Al ₂ Oz / Zeolite (59.8 Macc%) / Pt (0.3 Macc%) / Pd (0.2 mass%) significantly increased the content of iso-paraffins by 35.1 mass% and OCH by 12 , 2 points. US 8349754 B2, 01/08/2013.

The need to use two expensive metals (platinum and palladium) as well as their undesirably high total content (0.5 mass%) with a relatively low yield (46.22 mass%) of the target product (mixture of iso-paraffins) are the main disadvantages of the described catalyst.

A known catalyst of the following composition β-zeolite / Ce for the process of isomerization of n-paraffins. US 7119042 B2, 10/10/2006. The catalyst based on β zeolite is attractive from the point of view of the absence of expensive metals (platinum, palladium and others) in the composition, however, it is characterized by a low yield of iso-paraffins - not more than 31 mass% (400 ° C, 1 atm, feed: n-hexane) and rapid decontamination - coke deposition is more than 8.0 mass% with a process duration of 4.3 hours

A catalyst based on a modified ZSM-5 zeolite of the composition CsGeZSM-5 / Pt (l, 0 mass%) is described and tested in the process of reforming light naphtha. The the catalyst allowed to increase the value of OCH by 27 points, reaching a value of 78 for the obtained reformate (525 ° C, 1 atm). EP 2507195 A4, 10.26.2014.

However, the isomerization selectivity was low. Thus, the increase in the content of 2-methylpentane amounted to only 2.5 vol%, 2,3-dimethylbutane - 2.3 vol% (compared to raw materials). At the same time, the proportion of olefin formation was high: the increase in 2-methyl-substituted C6 isomeric olefins was 7.1 vol%, the increase in 3-methyl-substituted C6 isomeric olefins exceeded 13 vol% (compared to raw materials).

Thus, the main contribution to the increase in the RPI of the reformate was made by the formed olefins, which, along with the high temperature of the process (525 ° C), is a significant drawback of this catalyst.

A number of catalysts containing 20–90 mass% of the modified zeolite ZSM-22 were tested in the isomerization process (temperature 270–285 ° С, pressure 60 atm) of n-dodecane as a model alkane. Catalysts of the following compositions: АbОз / AgZSM-22 / Pt, Al ₂ 0 ₃ / AgZSM-22 / Pd, Al ₂ 0 ₃ / AuZSM-22 / Pt, Al ₂ 0 ₃ / AgAuZSM-22 / Pt, Al ₂ 0 ₃ / AgZSM-22 / Pt / Pd allowed to achieve the conversion n-dodecane in the range of 80.3 - 83.1 mass%. CN 100594063 C, 03/17/2010.

However, the selectivity for the formation of isomeric С12 alkanes did not exceed 88.7 mass%, indicating that, despite the low temperature (up to 285 ° С) and high pressure (60 atm) of the process, part of the feed (n-dodecane) was inevitably involved in adverse reactions of cracking. The use of two or more expensive metals along with their high content (Pt up to 1.20 mass%, Pd up to 3.7 mass%, Ag up to 12.0 mass%, Au up to 3.5 mass%) and also relatively low selectivity of formation the target product (a mixture of isomeric C12 alkanes) are the key disadvantages of this series of catalysts.

Despite the positive role of isomerization reactions among the target transformations of the reforming process, not all types of zeolites, as components of catalysts with high isomerizing activity, received equal attention throughout the study. So, unlike aluminosilicates, silicoaluminophosphates (SAPO) are relatively poorly studied for activity and selectivity in normal structure hydrocarbon isomerization catalysts.

As noted, the activity of zeolites for each type of catalytic reactions is completely determined by a complex set of unique properties, to which, primarily include acidity and porosity. Acidity i.e. the nature, strength, and number of acid sites of a zeolite, and porosity, namely, the effective width and geometry of the channels, determine the specific activity and selectivity of the catalytic transformations occurring in the presence of this zeolite.

A competing side process during catalytic isomerization is catalytic cracking, which inevitably leads to undesirable hydrocarbon losses due to the formation of low-value C ₁ -C4 gases. Both the target isomerization reaction and the side cracking reaction proceed with the participation of the acid centers of zeolites. Thus, the excessively low acidity of zeolites will lead to a decrease in the proportion of the target isomerization reaction, while the increased acidity of zeolites will lead to an intensification of the side cracking reaction. In this regard, for the design of the optimal catalytic system for the isomerization of n-alkanes, it is necessary to use a compromise option - medium acid zeolites.

Unlike the widely used strongly acidic aluminosilicates, silicoaluminophosphates are medium acid zeolites, and therefore do not require additional modification in order to reduce acidity (deposition of metals such as Zn, Cs, Ge and others).

Along with this, the silicoaluminophosphates of the ATO, AEL, and AFO structures have a one-dimensional system of disjoint channels with predominantly average effective widths, which limits the depth of isomerization of n-alkanes, thereby preventing the formation of easily cracked highly branched isomers, and, as a result, avoids undesirable loss hydrocarbons for the formation of low-value C ₁ -C4 gases.

Due to the combination of the listed properties of silicoaluminophosphates, these zeolites undoubtedly represent promising objects of research in the framework of creating a catalyst with increased isomerizing activity for the reforming process. At the same time, the potential of silicoaluminophosphates as components of isomerization catalysts is not limited by the use of individual SAPO zeolites, but also consists in combining SAPO zeolites of various structures and combining SAPO zeolites with aluminosilicates in the composition of the catalyst.

The closest in technical essence and the achieved technical result to the proposed catalyst with increased isomerizing activity is a catalyst containing a silicoaluminophosphate zeolite of structure AEL, of the general composition: AI2O3 / SAPO-I I / M, where M = Pt or Pd, applied to a carrier of composition AI2O3 / SAPO-II from a solution of H ₂ PtCl ₆ (by impregnation method) and Pd ( NH ₃ ) 4Cl2 (by cation exchange method), respectively. CN 1283668 A, 02/14/2001. The effectiveness of this catalyst was tested in the process of isomerization of n-octane as a model alkane at a temperature of 360 ° C using systems AI2O3 / SAPO-11 (70 Macc%) / Pt (0.50 mass%) and Al ₂ 0 ₃ / SAPO-l 1 (30; 50; 70 mass%) L (0.30; 0.50; 0.60; 1.00 mass%), representative experimentally obtained results are presented in Table 1. The presented results (Table 1) clearly demonstrate that maximum selectivity (91.09%) was achieved in the case of a combination of AI2O3 / SAPO-11 (70 Macc%) / Pd (0.60 mass%). A decrease in the Pd content by 0.1 mass% inevitably led to a decrease in selectivity by 6.07% (from 91.09 to 85.02%), while the yield of the mixture of the target isomeric alkanes C8 only slightly increased by 1.23%. This fact clearly indicates a marked increase in the contribution of undesirable side reactions to the process, making a further decrease in the Pd content impossible.

The effectiveness of the catalyst AI2O3 / SAPO-II / M, where M = Pt or Pd in the process of isomerization of n-octane (temperature 360 ° C) are presented in table 1.

Table 1

In the case of using a platinum-based system with a Pt content as high as 0.50 mass%, the selectivity for the formation of isomeric C8 alkanes did not exceed 79.00%, which resulted in a low yield (<42.00%) of the mixture of target compounds .

Thus, the high negative sensitivity of the selectivity of the isomerization process to a decrease in the amount of the metal component in the catalyst and, as a result, an undesirable high content of such expensive metals as Pt (0.50 mass%) and Pd (0.50-0.60 mass%) are significant disadvantages of this catalyst. This makes the industrial implementation of the process unprofitable from an economic point of view, necessitating further optimization of the composition of the catalyst, aimed at reducing the content of expensive metals along with an additional increase in the selectivity of isomerization.

The technical task of the invention is to develop a catalyst with increased isomerizing activity, containing not more than 0.3 wt% platinum and allowing efficient isomerization of alkanes of normal structure (n-alkanes) in the process of reforming hydrotreated gasoline fractions.

Disclosure of invention

The technical result from the implementation of the claimed group of inventions is to increase the efficiency of isomerization of n-alkanes in the reforming process of hydrotreated gasoline fractions and to achieve a selectivity of formation of isomeric alkanes (iso-alkanes) of not less than 92.0 mass% with an increase in the content of iso-alkanes in reformate (stabilized catalysis) ) not less than 14.0 mass% relative to raw materials. The best embodiment of the invention

The technical result is achieved in that the catalyst according to the first embodiment contains platinum and tin deposited on a carrier containing silicoaluminophosphate zeolite SAPO-31 or silicoaluminophosphate zeolite SAPO-11 with the following content of components, wt.%:

platinum 0.1-0.30 silicoaluminophosphate zeolite SAPO-31 or

silicoaluminophosphate zeolite S APO-11 10.0-60.0

tin 0.07-0.30

the rest of the alumina, as well as the fact that it additionally contains a zeolite of the FAU structure in an amount of 10.0-60.0 mass%, and as a zeolite of the FAU structure is USY aluminosilicate in the FI * form with a molar ratio S1O2 / AI2O3 of 82.6. The technical result is achieved by the fact that the catalyst according to the second embodiment contains platinum deposited on a carrier containing a mixture of silicoaluminophosphate zeolite SAPO-31 and silicoaluminophosphate zeolite SAPO-11 with the following components, wt.%:

platinum 0.1-0.30

a mixture of silicoaluminophosphate zeolite S AROZ 1

and silicoaluminophosphate zeolite S APO-11 10.0-60.0

the rest of the alumina, as well as the fact that it additionally contains a zeolite of the FAU structure in an amount of 10.0-60.0 wt%, and as a zeolite of the FAU structure, USY aluminosilicate in Н * form with a molar ratio Si0 ₂ / A- ₂ 0 ₃ equal to 82.6 and tin in an amount of 0.07-0.30 mass%.

To prepare the catalyst, a support is synthesized containing:

- silicoaluminophosphate zeolite SAPO-31 or silicoaluminophosphate zeolite SAPO-11 (10.0-60.0 mass%), alumina and, in particular, zeolite structure FAU

(10.0-60.0 mass%); platinum (0.1-0.3 mass%) is successively applied to the carrier by cation exchange from an aqueous solution of platinum ammonia (Pt (NH ₃ ) ₄ Cl ₂ ) or by impregnation from an aqueous solution of hexachloroplatinic acid (H ₂ PtCl ₆ ) and tin (0.07-0.30 mass%)

or

- a mixture of silicoaluminophosphate zeolite S APO-31 and silicoaluminophosphate zeolite S APO-11 (10.0-60.0 mass%), alumina and, in particular, zeolite structure FAU (10.0-60.0 mass%); platinum (0.1-0.3 mass%) is successively applied to the carrier by cation exchange from an aqueous solution of platinum ammonia (Pt (NH ₃ ) ₄ Cl ₂ ) or by impregnation from an aqueous solution of hexachloroplatinic acid (H ₂ PtCl ₆ ) and, in the particular case, tin (0.07-0.30 mass%).

Examples of carrying out the invention

The invention is illustrated, but not limited to, by the following examples. Example 1

The preparation of catalyst Ns 1 is carried out by synthesis of a carrier comprising 10 mass% of silicoaluminophosphate zeolite S APO-31 and alumina, and subsequent sequential deposition of 0.3 mass% of platinum onto the carrier by cation exchange from an aqueous solution of platinum ammonia (Pt (NH ₃ ) ₄ Cl ₂ ) and 0.20 mass% tin by impregnation by moisture absorption from a solution of SnCl ₄ ^x 5H ₂ 0 in a mixture of concentrated hydrochloric acid (37 mass%) and distilled water.

The preparation of catalyst N ° 1 includes the following stages:

1. To prepare 50 g of the support in a porcelain mortar, 5.48 g of SAPO-31 silicoaluminophosphate zeolite powder and 59.31 g of pseudoboehmite are mixed, grinding the resulting mixture to homogeneity.

2. To the resulting mixture, with constant stirring, 50.0 ml of a solution consisting of 1.91 ml of concentrated (65 mass%) nitric acid and 3.53 ml of triethylene glycol (99 mass%) are poured in small portions, the rest is distilled water. Stirring is continued until a uniform paste is obtained.

3. The resulting paste is molded using a piston extruder with a die of 1.5 mm diameter.

4. The resulting extrudates are dried at room temperature for 15 hours, dried in a drying oven with a stepwise rise in temperature (60, 80, PO ° C) and holding at each temperature for 3, 3 and 2 hours, respectively. The dried extrudates are then broken into granules 1.5 to 2.5 mm long.

5. The obtained granules of the carrier are gradually heated for 10 hours in a muffle furnace to a temperature of 550 ° C and calcined at this temperature for 10 hours with a constant supply of air.

6. To apply platinum by cation exchange, a solution is prepared by mixing 26.0 ml of distilled water, 37.5 ml of an aqueous solution of Pt (NH ₃ ) ₄ Cl2 with a concentration of 2.23 mg Pt ml and 2.7 ml of aqueous (25 wt% ) YSCHEN.

7. Weigh 28.70 g of carrier granules calcined at a temperature of 550 ° C, pour the granules with a prepared solution for applying platinum, and incubate in a thermostatic water bath under reflux at 95 ° C for 6 hours, then cool to room temperature and additionally incubated for 18 hours at room temperature ..

8. After the end of the platinum deposition step, the solution is decanted, and the resulting catalyst is dried in an oven with a stepwise rise in temperature (60, 80, PO ° С) and holding at each temperature for 3, 3 and 2 hours, respectively. 9. The dried granules of the catalyst are gradually heated for 24 hours in a muffle furnace to a temperature of 500 ° C and calcined at this temperature for 3 hours with a constant supply of air.

10. An impregnation solution is prepared by completely dissolving 0.061 g of SnCLjxStfeO (99.8 mass% of the basic substance) in a mixture of 0.23 ml of concentrated (37 mass%) hydrochloric acid and distilled water, with a total volume of 8.61 ml.

11. Weigh 11.33 g of catalyst granules calcined at a temperature of 500 ° C, which are then poured with the prepared impregnating solution and incubated at room temperature for 16 hours.

12. After the end of the impregnation stage, the resulting catalyst is dried in an oven with a stepwise rise in temperature (60, 80, 110 ° C) and holding at each temperature for 3, 3 and 2 hours, respectively.

Example 2

The preparation of catalyst N ° 2 is carried out similarly to the catalyst Ne 1, the preparation of which is described in Example 1, except that the content of silicoaluminophosphate zeolite SAPO-31 is 40 mass%, after applying platinum to the dried and calcined at a temperature of 500 ° C, the catalyst granules are applied 0 , 07 mass% of tin.

Example 3

The preparation of catalyst Ν »3 is carried out similarly to the catalyst Ν ° 2, the preparation of which is described in Example 2, except that the carrier contains 10 mass% (5.28 g) of silicoaluminophosphate zeolite SAPO-11 instead of silicoaluminophosphate zeolite S APO-31.

Example 4

The preparation of catalyst Ν ° 4 is carried out similarly to the catalyst Ν ° 2, the preparation of which is described in Example 2, except that the carrier contains 60 wt% (31.70 g) of a mixture of silicoaluminophosphate zeolite S APO-31 and silicoaluminophosphate zeolite SAPO-11 instead of silicoaluminophosphate zeolite SAPO-31.

Example 5 The preparation of catalyst N ° 5 is carried out similarly to the catalyst N ° 2, the preparation of which is described in Example 2, except that 0.1 mass% of platinum is applied to the support.

Example 6

The preparation of catalyst Ν ° 6 is carried out similarly to the catalyst JN ° 4, the preparation of which is described in Example 4, except that the finished catalyst does not contain tin.

Example 7

The preparation of catalyst N ° 7 is carried out similarly to the catalyst N ° 2, the preparation of which is described in Example 2, except that the content of silicoaluminophosphate zeolite SAPO-31 is 60 mass%, after applying platinum to the dried and calcined at a temperature of 500 ° C, the catalyst granules are applied 0.30 mass% of tin.

Example 8

The preparation of catalyst N ° 8 is carried out similarly to the M 7 catalyst, the preparation of which is described in Example 7, except that the support additionally contains 10 wt% zeolite of the FAU structure (5.28 g of USY aluminosilicate in H * form with a molar ratio S1O2 / AI2O3 equal to 82.6), the finished catalyst does not contain tin.

Example 9

The preparation of catalyst Ν ° 9 is carried out similarly to the catalyst Ν ° 8, the preparation of which is described in Example 8, except that the carrier contains 15 wt.% Silicoaluminophosphate zeolite SAPO-11 instead of 40 wt.% Silicoaluminophosphate zeolite SAPO-31, the carrier additionally contains 60 wt.% FAU structure zeolite (USY 31.68 g of aluminosilicate in H * form with a molar ratio S1O2 / AI2O3 equal 82.6), application of platinum on a support formed by impregnation of an aqueous solution of hexachloroplatinic acid (KUCHSL _b), after the application of platinum to the dried d catalyst applied Anulov 0.10 wt% tin Ν ° similarly to Catalyst 1, the preparation of which is described in Example 1.

The application of platinum on a carrier by impregnation from an aqueous solution of hexachloroplatinic acid (NgRu _b ) involves the following steps: 1. Prepare an impregnation solution by mixing 29.7 ml of distilled water, 3.03 ml of an aqueous solution of H ₂ P1: C1 _b with a concentration of 11.30 mg Pt / ml, 0.13 ml of concentrated (37 mass%) hydrochloric acid and 0 , 16 ml of “glacial” acetic acid.

2. 12.60 g of carrier granules calcined at a temperature of 550 ° C are weighed, the granules are poured into the prepared impregnating solution and kept at room temperature for 18 hours.

3. After the end of the impregnation step, the solution is decanted, the resulting catalyst is dried in an oven with a stepwise rise in temperature (60, 80, 110 ° С) and holding at each temperature for 3, 3 and 2 hours, respectively.

Example 10

The preparation of the catalyst Jfe 10 is carried out similarly to the catalyst Ν ° 9, the preparation of which is described in Example 9, except that the carrier contains 40 wt.% A mixture of silicoaluminophosphate zeolite SAPO-31 and silicoaluminophosphate zeolite SAPO-11 instead of 15 wt.% Silicoaluminophosphate zeolite S APO-11 , the finished catalyst does not contain tin and zeolite structure FAU.

Example 11

The preparation of catalyst JV 11 is carried out similarly to catalyst N ° 10, the preparation of which is described in Example 10, except that the content of the mixture of silicoaluminophosphate zeolite SAPO-31 and silicoaluminophosphate zeolite S APO-11 is 10 mass%, the carrier additionally contains 10 mass% of the zeolite structure FAU, after applying platinum to the dried granules of the catalyst, 0.10 mass% of tin is applied, similarly to the catalyst N ° 1, the preparation of which is described in Example 1.

The composition of the catalyst samples, the preparation of which is described in Examples 1-11, are presented in Table 2. To conduct an experimental comparative assessment of the effectiveness of the samples of the claimed catalyst, a comparison catalyst was selected - a modern commercially available platinum-rhenium reforming catalyst, the composition of which is also presented in Table 2.

Table 2 The composition of the claimed catalyst samples based on zeolites of the ATO or / and AEL structure: silicoaluminophosphate zeolite SAPO-31 or silicoaluminophosphate zeolite S APO-11 or a mixture of silicoaluminophosphate zeolite SAPO-31 and silicoaluminophosphate zeolite SAPO-11. The composition of the catalyst comparison. The composition of the catalyst, mass%

Silicoaluminophosphate

zeolite structure

Method

ATO and / or AEL Zeolite

catalytic application

Pt Sn Re mixture of A1 ₂ O ₃ structure of platinum mash

SAPO SAPO SAPO-31 FAU *

-31 -11 +

SAPO-11

Cationic

1 0.3 0.20 - 10 - - - Other exchange

Cationic

2 0.3 0.07 - 40 - - - Other exchange

Cationic

3 0.3 0.07 - - 10 - - Other exchange

Cationic

4 0.3 0.07 - - - 60 - Other exchange

Cationic

5 0.1 0.07 - 40 - - - Other exchange

Cationic

6 0.3 - - - - 60 - Other exchange

Cationic

7 0.3 0.30 - 60 - - - Other exchange

Cationic

8 0.3 - - 40 - - 10 Other exchange

9 Impregnation 0.3 0.10 - - 15 - 60 Else

10 Impregnation 0.3 - - - - 40 - Else

11 Impregnation 0.3 0.10 - - - 10 10 Else

Catalytic Mash

- 0.3 - 0.4 - - - - The rest of the comparison * - As the zeolite of the FAU structure, US Y aluminosilicate in the H ^" form with a molar ratio of S1O2 / AI2O3 of 82.6 was used.

Example 12

The catalysts N ° 1-11, prepared by the method described in Examples 1-11, respectively, and the comparison catalyst were tested in the process of low-temperature reforming carried out in a flow catalytic installation. This installation is equipped with a heated casing in which gas and liquid lines, a mixer, and a reactor are placed. The inner diameter of the reactor is 1.3 cm, the volume of the loaded catalyst is 10 cm ³ .

During testing, raw materials from a container located on an electronic scale are fed into the system by a high-pressure plunger pump. The exact mass of the feed is recorded based on the readings of the electronic balance. The raw material enters the mixer, where it is mixed with hydrogen, the reaction mixture enters the reactor. The resulting products are discharged from the bottom of the reactor and sent to a separator, where the gas phase (hydrogen-containing gas) is separated from liquid catalysis. Liquid catalyzate from the separator enters the refrigerator-sampler, cooled to -10 ° C with antifreeze, continuously circulating through the “jacket” of the apparatus. Periodic sampling of liquid catalysis is carried out from the refrigerator-sampler for analysis.

The reforming process is carried out under the following conditions: temperature 360-380 ° C, pressure 1.5-2.0 MPa, bulk feed rate 1.5-3.0 h ^"1 , hydrogen / feed ratio = 1300: 1 nl / l .

As a raw material, a hydrotreated gasoline fraction with the following characteristics was used:

- content of C5 + n-alkanes, mass%: 25.6;

- content of C5 + iso-alkanes, mass%: 33.4.

The following three parameters, shown in Tables 3 and 4, serve as a measure of the quantitative assessment of the effectiveness of the catalyst in the isomerization of n-alkanes during low-temperature reforming:

1) the selectivity of the formation of iso-alkanes, mass%;

2) the yield of a mixture of iso-alkanes, mass%; 3) an increase in the content of iso-alkanes in reformate (stabilized catalysis)

(W (HA) _P -W (HA) C) * 100 „ _T , _A , _{17 / A H}

relative to raw materials: W [HA ₎ ' ^where ^ (uA) p ^u ”(uA) c is the content of C5 + isoalkanes in the reformate and the feed, respectively, mass%.

Calculations of the selectivity of the formation of iso-alkanes and the yield of the target product (mixture of iso-alkanes) are given for C5 + iso-alkanes, which corresponds to the composition of the stabilized catalysis from which the light hydrocarbons C1-C4 are removed.

In full accordance with the technical task, the developed catalyst based on silicoaluminophosphate zeolite of the ATO or / and AEL structure is characterized by a platinum content of not more than 0.3 mass% and provides:

- the selectivity of the formation of iso-alkanes is not less than 92.0 mass%,

- an increase in the content of iso-alkanes in reformate (stabilized catalysis) is not less than 14.0 mass% relative to raw materials.

The resulting catalyst based on silicoaluminophosphate zeolites of the ATO or / and AEL structure is significantly more effective than the platinum-rhenium comparison catalyst within all three of the above parameters at process temperatures not exceeding 380 ° C (Tables 3 and 4). In addition, for the platinum-rhenium comparison catalyst, the total content of expensive active metals (platinum and rhenium) is 0.6 mass%, which is more than 2 times the corresponding value (not more than 0.3 mass% Pt) for the claimed catalyst (Table 2).

Table 3

The effectiveness of the claimed catalyst based on silicoaluminophosphate zeolites of the ATO or / and AEL structure and a comparison catalyst in n-alkanes isomerization reactions during the low-temperature reforming of a hydrotreated gasoline fraction. Process conditions: pressure 1.5 MPa, a volumetric feed rate of 1.5 h ^"1 , the ratio of hydrogen to feed = 1300: 1 nl / l.

Selectivity

Temperature

Formation Alkane mixture yield in process reformate

Catalyzed C5 + iso - C5 + iso (stabilized

reforming

alkali, alkanes, mass% catalysis)

° C

mass% of raw materials, mass%

1 380 99.8 19.3 14.8

2 380 93.6 48.2 37.0 3 380 93.0 47.9 36.8

4 380 93.0 47.9 36.7

5 380 93.5 40.0 30.7

6 360 98.7 42.9 32.9

7 380 99.6 40.6 31.2

8 380 92.7 47.8 36.7

9 380 93.5 48.2 37.0

10 380 97.8 44.0 33.8

11 380 99.3 41.2 31.6

Katali 380 * 62.3 2.6 2.0

-congestion

compared to 400 21.3 2.2 1.7

-niya

- at temperatures less than 380 ° C, conversion of n-alkanes was not observed.

Table 4

The effectiveness of the claimed catalyst based on a mixture of silicoaluminophosphate zeolites of the ATO or / and AEL structure in the process of low-temperature reforming of a hydrotreated gasoline fraction. Process conditions: temperature 380 ° C, hydrogen / feed ratio = 1300: 1 nl / l.

Increase

Selectivity

Volumetric

Formation of a mixture of C5 + alkanes in reformate

Pressure, speed

Cataly- C5 + iso-iso- (stabilized

MPa feed

mash of alkanes, alkanes, catalysis) raw materials, h ^"1

mass% mass% relative to raw materials, mass%

4 2.0 1.5 94.5 48.7 37.4

10 1.5 3.0 99.5 43.7 33.5

Claims

Claim

1. The catalyst for the isomerization of n-alkanes during the reforming of hydrotreated gasoline fractions, containing platinum, silicoaluminophosphate zeolite and alumina, characterized in that it additionally contains tin, and as silicoaluminophosphate zeolite - silicoaluminophosphate zeolite SAPO-31 or silicoaluminophosphate following SAPO-aluminum phosphate content of components, mass%:

platinum 0.1-0.30 silicoaluminophosphate zeolite SAPO-31 or

silicoaluminophosphate zeolite S APO-11 10.0-60.0 tin 0.07-0.30 aluminum oxide the rest.

2. The catalyst according to claim 1, characterized in that it further comprises a zeolite of the FAU structure in an amount of 10.0-60.0 mass%.

3. The catalyst according to claim 2, characterized in that the zeolite structure FAU contains aluminosilicate USY in H ^{1 "} form with a molar ratio of S1O2 / AI2O3 equal to 82.6.

4. The catalyst for the isomerization of n-alkanes during the reforming of hydrotreated gasoline fractions containing platinum, silicoaluminophosphate zeolite and alumina, characterized in that it contains a mixture of silicoaluminophosphate zeolite SAPO-31 and silicoaluminophosphate zeolite S APO-11 with the following content of components, wt%:

platinum 0.1-0.30 a mixture of silicoaluminophosphate zeolite SAPO-31 and

silicoaluminophosphate zeolite S APO-11 10.0-60.0 aluminum oxide the rest.

5. The catalyst according to claim 4, characterized in that it further comprises a zeolite of the FAU structure in an amount of 10.0-60.0 mass%.

6. The catalyst according to claim 5, characterized in that as the zeolite of the structure, the FAU contains USY aluminosilicate in H + form with a molar ratio S1O2 / AI2O3 of 82.6.

7. The catalyst according to claim 4, characterized in that it further comprises tin in an amount of 0.07-0.30 mass%.