RU2747870C1 - Method for producing benzines or concentrates of aromatic compounds - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a method of producing benzines or concentrates of aromatic compounds, in which three streams are used as raw material, first of which includes a hydrocarbon fraction, second oxygenate stream comprises the third stream comprises the olefin-containing fraction using three reaction zones filled with a zeolite catalyst, wherein the olefin-containing fraction comprises from 10 to 50 wt% olefins C₂-C₄ and from 0.5 to 8 wt% hydrogen, first stream is fed into at least one reaction zone, a second stream is fed into a first reaction zone or a third reaction zone, wherein when the second stream is fed into a first zone, distribution of the third stream between two reaction zones is 35-65 wt% / 65-35 wt%, and when the second stream is fed into the third reaction zone, the distribution of the third stream between the two reaction zones is 25-45 wt% / 75-55 wt%.

EFFECT: method enables to process hydrogen-containing streams of diluted olefins without separation of hydrogen, without recycling of gaseous products and without using internal heat exchangers, while increasing output and RON of the product.

31 cl, 12 ex, 8 tbl

Description

The invention relates to the field of oil refining and petrochemical industries. More specifically, the invention relates to a method for the production of gasolines or concentrates of aromatic compounds by co-processing hydrocarbon fractions, oxygenates and olefin-containing fractions.

The following terms are used in the description:

Gasoline - commercial gasoline or the main component (base) for the production of gasoline. In particular, gasoline obtained by the proposed method can be used to obtain motor gasolines by compounding methods (mixing gasoline fractions obtained by various oil refining processes). For example, according to the proposed method, a basis for the production of motor gasoline of ecological class K5 of the AI-92 brand according to GOST 32513-2013 can be produced. In some cases, the gasoline obtained by the proposed method may not meet all the requirements for commercial gasoline by a particular region or organization. For example, the benzene content of produced gasoline can exceed 1.0% by volume. As another example, the aromatic content of the gasoline produced may exceed 35 vol%. As gasoline can be considered a liquid hydrocarbon product produced by the proposed method.

Hydrocarbon fraction - a fraction of the gasoline boiling range (the boiling point is not standardized, the boiling point is not more than 215 ° C). In particular, the end of the boiling point can be 200 ° C, 180 ° C, 160 ° C or 85 ° C. Preferably, the end boiling point is not higher than 180 ° C. The onset of boiling can be, for example, 62 ° C, 85 ° C, 140 ° C. Preferably, the initial boiling point is at least 62 ° C.

Oxygenate is an aliphatic alcohol or ether. It can be selected from the group including: methanol, crude methanol, technical methanol, ethanol, dimethyl ether, other aliphatic alcohols, other ethers, as well as their mixtures, including with water. May contain impurities such as aldehydes, carboxylic acids, esters, aromatic alcohols. The method does not involve the use of unsaturated (unsaturated) alcohols, for example, allyl alcohol, but their presence is possible as impurities.

Olefin-containing fraction - a fraction containing 10-50 wt.% Of C ₂ -C ₄ olefins (ethylene, propylene, normal butylenes, isobutylene). The olefin-containing fraction may contain inert or weakly reactive components other than olefins, for example: methane, ethane, propane, butane, hydrogen, nitrogen. For example, the olefin-containing fraction may contain 0.5 to 8 wt% hydrogen, preferably 2.3 to 8.0 wt% hydrogen. Preferably, the mass fraction of C ₅₊ hydrocarbons in the olefin-containing fraction is not more than 5.0 wt%. Preferably, the volume fraction of hydrogen sulfide in the olefin-containing fraction is not more than 0.005%.

The reaction zone is a separate volume in the reactor containing the catalyst. Several consecutive reaction zones can be located in one reactor. For example, the reaction zones can be shelves in a shelf reactor. Also, each reaction zone can be in a separate reactor. A separate reactor can be used as the reaction zone.

OCHI is the octane number determined by the research method. It can be determined, for example, according to ASTM D2699 or according to GOST 8226.

C _n - hydrocarbons with the number of carbon atoms n.

C _{n +} - hydrocarbons with the number of carbon atoms equal to or more than n.

REE - rare earth elements.

DME stands for dimethyl ether.

SGKK is a dry catalytic cracking gas.

FAU - fraction of aromatic hydrocarbons.

Mass feed rate of raw materials, h ^-1 - the amount of raw materials passed per unit time through a unit mass of the catalyst. For example, the mass feed rate of the i-th component:

(1)

(one)

– массовый поток i-го компонента на входе, г/ч.Where

- mass flow of the i-th component at the inlet, g / h.

m _cat is the mass of the catalyst, g.

Conversion is the ratio of the amount of raw material that has reacted to the amount of raw material fed into the reaction. For example, the conversion of the i-th component:

(2)

(2)

– массовый поток i-го компонента на входе, г/ч.Where

- mass flow of the i-th component at the inlet, g / h.

– массовый поток i-го компонента на выходе, г/ч.

- mass flow of the i-th component at the outlet, g / h.

Selectivity is the ratio of the amount of the target component to the total amount of hydrocarbons obtained in the given process. For example, the selectivity of the i-th component of the product:

(3)

(3)

– массовый поток i-го компонента на выходе, г/ч,Where

- mass flow of the i-th component at the outlet, g / h,

– суммарный массовый поток всех произведенных углеводородов, г/ч.

- total mass flow of all produced hydrocarbons, g / h.

The percentage substitution of the oxygenate for the olefin-containing fraction (% substitution) is calculated as follows:

(4)

(four)

– мольный поток i-го подаваемого оксигената, моль/ч,Where

- molar flow of the i-th supplied oxygenate, mol / h,

k _i - coefficient advising the i-th supplied oxygenate. The k _i factor is 0.5 for methanol, 1 for other oxygenates (eg ethanol, propanol, DME).

– мольный поток j-го подаваемого олефина, моль/ч.

- molar flow of the j-th fed olefin, mol / h.

For example, if it is necessary to replace methanol with dry catalytic cracking gas containing ethylene, the replacement percentage is calculated as follows:

(5)

(five)

– мольный поток подаваемого метанола, моль/ч,Where

- molar flow of supplied methanol, mol / h,

– мольный поток подаваемого этилена, моль/ч,

- molar flow of supplied ethylene, mol / h,

0.5 is the coefficient corresponding to methanol.

Similarly, if ethanol is used as the oxygenate, and the olefin-containing fraction contains ethylene, propylene and butylenes, the percentage of substitution is calculated as follows.

(6)

(6)

where n _ethanol is the molar flow of supplied methanol, mol / h,

n _ethylene - molar flow of supplied ethylene, mol / h,

n _propylene - molar flow of supplied propylene, mol / h,

n _butylenes - total molar flow of supplied butylenes (including isobutylene), mol / h,

1 - coefficient for ethanol.

LEVEL OF TECHNOLOGY

There are several examples of joint processing of hydrocarbon fractions, oxygenates and olefin-containing fractions into gasolines or concentrates of aromatic compounds.

Patent RU 2671568 dated 09/27/2016 refers to a complex plant for processing a mixture of C ₁ -C ₁₀ hydrocarbons of various composition (low-octane gasoline fractions n.c.-180 ° C, 90-160 ° C or narrower fractions, pentane-heptane (hexane ) fractions, propane-butane fractions, BFLH and / or lower olefins C ₂ -C ₁₀ and / or their mixtures with each other, and / or with C ₁ -C ₁₀ paraffins, and / or with hydrogen) in the presence of oxygen-containing compounds, comprising one or more parallel-located sectioned adiabatic reactors, consisting of one or more stationary beds (sections) of a zeolite-containing catalyst with a supply or removal of heat between the beds (sections) of the catalyst. The proposed installation allows you to obtain high-octane gasolines, diesel fractions or aromatic hydrocarbons.

The disadvantage of the invention is the need to add significant amounts of isobutane to the feedstock in order to control the temperature of the reaction zones. Isobutane is a highly demanded refinery product with a high cost. Its redirection to the processing of the hydrocarbon fraction will lead to an increase in the cost of producing gasoline or aromatic hydrocarbon concentrate.

The disadvantage of the invention is also the circulation of a part of the gaseous product directly through the catalyst bed. Recycling the gaseous product complicates the required equipment and its maintenance. Also, this approach does not allow working with sulfur-containing raw materials without involving additional purification methods. In particular, the installation contains a unit for removing sulfur compounds using the hydrogen-containing gas obtained in the process from at least a portion of the hydrocarbon feedstock. Incomplete purification of raw materials from sulfur can lead to the production of a gaseous product contaminated with sulfur compounds. Recycling of such a gaseous product will lead to accelerated poisoning of the catalyst with gaseous sulfur-containing compounds (hydrogen sulfide, mercaptans).

Application for invention WO2017155431 (PCT / RU2017 / 050009 ) describes a method for producing gasolines from raw hydrocarbon fractions, fractions of gaseous olefins and oxygenates. As a reactor, a reactor is used containing at least two reaction zones with a zeolite-containing catalyst, between which there is additionally located means for mixing the reaction products of the previous reaction zone and supplied methanol or other oxygenates and olefin-containing raw materials, and through the unit for feeding streams:

• to the first reaction zone of the reactor: a stream of methanol or other oxygenates and olefin-containing raw materials and a stream of raw hydrocarbon fractions,

• to the second reaction zone of the reactor - a stream of methanol or other oxygenates and olefin-containing raw materials.

As a disadvantage of the method, the need for additional heat supply to the reaction zones can be considered, then at low methanol consumption (less than 20% of the mass of the converted raw material), including due to additional overheating of the feed stream supplied to the last and / or penultimate reaction zones (maximum up to 500 ° C); or by using isothermal reaction zones as one or two of the last reaction zones of the reactor.

This method is the closest to the present invention and is taken as a prototype.

However, none of the documents described does not investigate how the options for the distribution of raw materials between the reaction zones affect the parameters of the process. It is also not disclosed that the use of raw materials of a certain composition with an appropriate distribution between the reaction zones will eliminate the recycle of gaseous products.

DISCLOSURE OF THE INVENTION

As the technical results of the present invention are considered:

1. increasing the yield of liquid hydrocarbon product;

2. lowering the proportion of benzene in the liquid hydrocarbon product;

3. an increase in the content of highly branched isoparaffins in the product, mainly due to an increase in the formation of C ₇ isoparaffins;

4. improved selectivity for C ₉ alkylbenzenes;

5. the ability to exclude the recycling of gaseous products;

6. the ability to use low-demand olefin-containing fractions with a high hydrogen content as raw material and without its additional separation;

7. the possibility of partial replacement of oxygenate with olefin-containing fractions;

8. ensuring the minimum temperature drop in the end catalyst bed without the use of internal heat exchangers;

9. absence of oxygenates in the liquid hydrocarbon product;

10. Possibility of producing low-benzene aromatic concentrates;

11. Possibility of producing aromatic concentrate with a high content of C ₈ alkylbenzenes.

The above technical results are achieved due to the proposed method for producing a liquid hydrocarbon product containing aromatic compounds, in which three streams are used as raw materials, the first of which includes a hydrocarbon fraction, the second stream includes an oxygenate, the third stream includes an olefin-containing fraction, three reaction zones filled with zeolite catalyst, the product stream from the first reaction zone is fed to the second reaction zone, and the product stream from the second reaction zone is fed to the third reaction zone, wherein:

a. the olefin-containing fraction includes one or more olefins selected from the group consisting of: ethylene, propylene, normal butylenes, isobutylene, in a total amount of 10 to 50 wt%, and contains from 0.5 to 8 wt% hydrogen,

b. the first stream is fed to at least one reaction zone,

c. the second stream is fed to the first reaction zone, or to the third reaction zone,

d. wherein the third stream is fed into the second and third reaction zones when the second stream is fed into the first reaction zone, or into the first and second reaction zones when the second stream is fed into the third reaction zone,

e. moreover, when the second stream is fed into the first zone, the distribution of the third stream between the two reaction zones is 35-65 wt% / 65-35 wt%,

f. and when the second stream is fed to the third reaction zone, the distribution of the third stream between the two reaction zones is 25-45 wt% / 75-55 wt%.

It is possible to implement the invention in which the liquid hydrocarbon product containing aromatic compounds is gasoline if the content of aromatic compounds is less than 40 wt%, or the liquid hydrocarbon product containing aromatic compounds is an aromatic concentrate if the content of aromatic compounds is more than 40 wt%.

An embodiment of the invention is possible in which the first stream is preferably fed to the first reaction zone.

It is possible to implement the invention in which the hydrocarbon fraction contains normal paraffins in an amount of 15-24 wt%, isoparaffins in an amount of 42-56 wt%, naphthenes in an amount of 22-40 wt%, the rest is aromatic hydrocarbons and olefins.

It is possible to implement the invention, in which the hydrocarbon fraction can be selected from the group including straight-run gasoline, stable gas gasoline, light gas condensate, gasoline fraction with boiling points of about 62 ° - 85 ° C, raffinate, and mixtures thereof.

An embodiment of the invention is possible, in which the hydrocarbon fraction contains from 0 to 80 wt.% C ₆ hydrocarbons, preferably from 23 to 46 wt.% C ₆ hydrocarbons, most preferably from 36 to 46 wt.% C ₆ hydrocarbons.

An embodiment of the invention is possible, in which the hydrocarbon fraction contains from 0 to 70 wt.% C ₇ isoparaffins, preferably from 26 to 50 wt.% C ₇ isoparaffins, most preferably from 26 to 38 wt.% C ₇ isoparaffins.

It is possible to carry out the invention in which the oxygenate is selected from the group consisting of aliphatic alcohols, for example, methanol, ethanol, crude methanol, technical methanol, ethanol; ethers, for example, dimethyl ether, as well as mixtures thereof, including with water.

It is possible to carry out the invention in which the oxygenate may contain impurities, for example, aldehydes, carboxylic acids, esters, unsaturated alcohols.

An embodiment of the invention is possible, in which the olefin-containing fraction is selected from the group including products of fractionation of catalytic cracking gases, dry catalytic cracking gas, catalytic cracking wet gas, coking off gas, Fischer-Tropsch synthesis gases, thermal cracking gas, visbreaking gas, off gases hydrocracking, pyrolysis gas, gaseous waste from catalytic reforming, as well as mixtures thereof.

An embodiment of the invention is possible in which the olefin-containing fraction may include non-olefinic hydrocarbon components, for example, methane, ethane, propane, butane, and may contain inorganic gases, for example, nitrogen.

An embodiment of the invention is possible in which the olefin-containing fraction comprises 2.3-8.0 wt% hydrogen, preferably 3.2-8.0 wt% hydrogen.

An embodiment of the invention is possible, in which the mass fraction of C ₅₊ hydrocarbons in the first olefin-containing fraction is from 0 to 10.0 wt%, preferably from 0 to 5.0 wt%.

An embodiment of the invention is possible in which the olefin-containing fraction may include C ₅₊ olefins, for example, pentenes, hexenes.

An embodiment of the invention is possible, in which the volume fraction of hydrogen sulfide in the olefin-containing fraction is from 0.0 to 0.005%.

An embodiment of the invention is possible, in which the olefin-containing fraction includes dry catalytic cracking gas and contains from 25 to 40 wt.% Of C ₂ -C ₄ olefins.

An embodiment of the invention is possible in which the process pressure is from 1.5 to 4.0 MPa, preferably from 2.2 to 2.7 MPa.

It is possible to implement the invention, in which the temperature of the stream at the inlet to the first / second / third reaction zone is 340-450 ° C / 350-450 ° C / 350-450 ° C.

An embodiment of the invention is possible, in which the mass feed rate of the raw material is from 0.5 to 10 h ^-1 , preferably 1-3 h ^-1 .

It is possible to implement the invention, in which the temperature of the flow at the inlet to the first / second / third reaction zone is 340-380 ° C / 350-380 ° C / 350-380 ° C.

An embodiment of the invention is possible, in which the mass feed rate of the raw material is from 0.9 to 10 h ^-1 , preferably 1-3 h ^-1 .

It is possible to implement the invention, in which the temperature of the flow at the inlet to the first / second / third reaction zone is 390-450 ° C / 390-450 ° C / 390-450 ° C.

It is possible to implement the invention in which the mass feed rate of the raw material is from 0.1 to 0.9 h ^-1

A possible embodiment of the invention, in which the distribution of the catalyst over the reaction zones is 15-35 wt.% / 25-45 wt.% / 25-60 wt.% Of the total amount of catalyst for the first / second / third reaction zone, respectively, preferably 17-33 wt% / 28-43 wt% / 28-50 wt% of the total amount of catalyst.

An embodiment of the invention is possible, in which the hydrocarbon fraction is 50-85 wt.% Of the supplied raw material, preferably 54-73 wt.% Of the supplied raw material.

An embodiment of the invention is possible, in which the olefin-containing fraction is 20-35 wt.% Of the supplied raw material.

An embodiment of the invention is possible, in which the oxygenate is 3-14 wt.% Of the supplied raw material.

An embodiment of the invention is possible, in which the zeolite catalyst comprises:

a. zeolite of the ZSM-5 type with a SiO ₂ / Al ₂ O ₃ modulus from 43 to 95, in an amount from 65 to 80 wt%,

b. sodium oxide in an amount from 0.04 to 0.15 wt%,

c. zinc oxide in an amount of 1.0–5.5 wt%,

d. oxides of rare earth elements in a total amount of 0.5–5.0 wt%,

e. a binder comprising silicon dioxide, aluminum oxide, or mixtures thereof.

An embodiment of the invention is possible in which the zeolite catalyst does not contain platinum metals.

An embodiment of the invention is possible in which the rare earth elements are selected from the group including lanthanum, praseodymium, neodymium, cerium, and mixtures thereof.

An embodiment of the invention is possible, in which the reaction is carried out in the gas phase in a fixed catalyst bed.

CARRYING OUT THE INVENTION

To carry out the process, the hydrocarbon fraction, oxygenate and olefin-containing fraction are separated into several streams. The streams are fed to the reaction zones:

R ₁₀₁ - the first reaction zone;

R _{2 01} - the second reaction zone;

R _{3 01} - the third reaction zone.

The hydrocarbon fraction is fed to at least one reaction zone. For this, the hydrocarbon fraction can be separated into one, two or three streams. In particular, to carry out the experiments of Examples 1-11, the entire hydrocarbon fraction was distributed to the first reaction zone (i.e., no second and third hydrocarbon fraction streams were generated). For the experiment of Example 12, the hydrocarbon fraction was partitioned into three reaction zones (i.e., the first, second, and third hydrocarbon fraction streams were created).

It is also possible, if necessary, to distribute the entire flow of the hydrocarbon fraction only to the second or only to the third reaction zone. In another embodiment, the proposed process allows you to distribute the hydrocarbon fraction into several reaction zones.

The oxygenate is fed to the first reaction zone or to the third reaction zone. For this, the oxygenate stream is fed to either the first or third reaction zone.

The stream of the olefin-containing fraction is fed into the second and third reaction zones when oxygenate is fed into the first reaction zone, or into the first and second reaction zones when oxygenate is fed into the third reaction zone. For this, the olefin stream is split into two streams.

In the process, the product stream from the first reaction zone is fed to the second reaction zone and the product stream from the second reaction zone is fed to the third reaction zone.

In this case, each of the streams supplied to a specific reaction zone can be heated before or after mixing with other streams.

Feed streams fed to a particular reaction zone are mixed in a mixing zone located upstream of the catalyst bed of that reaction zone. The mixing zone of the reaction zone can be, for example:

• a layer of granules of neutral material placed in front of the layer of zeolite catalyst, for example, a protective layer, forecontact;

• connecting line (main) connecting the reaction zones;

• a heater (or preheater) located between the reaction zones.

The product stream from the third reaction zone is separated into a hydrocarbon product fraction and an aqueous product fraction . The aqueous fraction of the product is withdrawn.

The hydrocarbon fraction of the product is then separated into a liquid hydrocarbon (u / w) product and a gaseous product by means of fractionation and stabilization. In particular, settling and degassing of the aqueous phase, debutanization of the hydrocarbon phase, condensation of propane, etc. can be carried out. The gaseous product can be further separated into a gaseous product fraction enriched in C ₃ -C ₄ hydrocarbons and a gaseous product fraction enriched in C ₁ -C ₂ hydrocarbons.

The main component of a liquid hydrocarbon product is C ₅₊ hydrocarbons (hydrocarbons with five or more carbon atoms). Depending on the goals of a particular production, a liquid hydrocarbon product may contain not only C ₅₊ hydrocarbons, but also different amounts of dissolved gases C ₁ -C ₄ . In particular, in the production of motor gasolines, the presence of up to 3-5 wt.% Of dissolved gases in summer gasolines and up to 5-7 wt.% Of dissolved gases in winter gasolines is usually allowed. The gaseous product may include C ₁ -C ₄ hydrocarbons, nitrogen, hydrogen and other inorganic gases, as well as heavier hydrocarbons.

Product streams can be directed to external heat exchangers, such as recuperative heat exchangers, to heat the feed streams and pre-cool the product streams.

Examples of

The achieved results are shown below in examples 1-12. Examples 1-6, 12 and Comparative Example 7 show the case for the production of gasolines. Examples 8-11 show the possibility of obtaining concentrates of aromatic compounds.

The proposed process makes it possible to produce a liquid hydrocarbon product that can be used as gasoline or as a concentrate of aromatic compounds.

The difference between gasoline and aroma concentrate lies in the total aroma content of the product. There are states and enterprises that limit the maximum content of total aromatics in commercial gasolines at 35 vol. % (about 38-40 wt.% aromatics).

In this regard, a liquid hydrocarbon product with a total aromatic hydrocarbon content of not more than 40 wt% refers to gasolines. In particular, the proposed method makes it possible to produce a liquid hydrocarbon product that can be sold as commercial motor gasoline without additional compounding.

A liquid hydrocarbon product with a total aromatic hydrocarbon content of more than 40 wt% refers to concentrates of aromatic compounds. In particular, the proposed method makes it possible to produce a liquid hydrocarbon product that can be used as a high-octane aromatics concentrate, which plays the role of the main component in the compounding of motor gasolines.

Note that, depending on the state or enterprise, the maximum allowable content of aromatic compounds in commercial gasolines, different from 40 wt.%, Can be established.

The concentration of aromatics in the resulting liquid hydrocarbon product can be controlled using several parameters. In particular, an increase in the feed temperature and / or a decrease in the mass feed rate of the feed leads to an increase in the mass fraction of aromatics in the resulting liquid hydrocarbon product.

In particular, Examples 8-11 demonstrate the preparation of concentrates of aromatic compounds with an aromatic content of more than 40 wt.% At temperatures of 390-450 ° C and / or at mass feed rates from 0.1 to 0.9 h ^-1 . Such aromatic concentrates can be used as the main component in the compounding (mixing) of commercial gasolines. It is also possible to use concentrates of aromatic compounds for further processing by petrochemical methods.

Comparative example 7 differs from the examples according to the invention in that it does not correspond to the following feature of the proposed method:

• oxygenate is fed to the first reaction zone, or to the third reaction zone, while the olefin-containing fraction is fed to the second and third reaction zones when the second stream is fed to the first reaction zone, or to the first and second reaction zones when the second stream is fed to third reaction zone.

To carry out examples 1-12, a catalytic unit was used, including three reactors connected in series, with a total catalyst load of up to 9 liters. The reactors are designated as first, second and third reaction zones, R ₁₀₁ , R ₂₀₁ , R _301, respectively.

The reactors are structurally as close as possible to the adiabatic type, the heat exchange between the catalyst bed and the vessel is minimized. The catalyst baskets are placed in the reactor vessel so that a gap (approximately 2 mm) remains between the wall of the basket and the strong body. Each reactor is installed in a thermostat with three heating zones. Three thermocouples are placed between the surfaces of the heating elements and the outer surface of the reactor vessel. On the contrary, thermocouples are also located on the inner wall of the reactor basket casing. There is also an air gap not exceeding 3-4 mm between the inner surface of the thermostat and the outer surface of the reactor. The control loops maintain a constant temperature difference between the thermocouples at the outer wall of the reactor and the thermocouple opposite at the inner surface of the reactor basket

The products for analysis began to be taken 4 hours after the start of the feed.

Table 1 shows the chemical compositions of the hydrocarbon fractions used in examples 1-12 as feedstock. In particular, the 62-85 ° C fraction (fr. 62-85 ° C) is the benzene-forming part of the catalytic reforming feedstock (approximate boiling range 62-85 ° C). The raffinate is typically a mixture of predominantly gasoline-range hydrocarbons that have not been converted during the catalytic reforming process. The raffinate can be described as a by-product gasoline cut taken from an aromatic hydrocarbon extractive distillation unit. For example, the raffinate can be a by-product of the extractive distillation of the benzene-toluene fraction. Also, the raffinate can be a by-product of the extractive distillation of the toluene-xylene fraction.

The presented hydrocarbon fractions are characterized by a high content of isoparaffins, from 42-56 wt.%. Most of them are C ₇₊ isoparaffins with an octane number below 70 units. (from 23 to 48 wt.%). Such components are poorly processed into high-octane aromatics in standard gasoline production processes. They also have too high a molecular weight to serve as a raw material for the classical isomerization of C ₅ -C ₆ fractions to obtain high-octane motor gasoline. In this case, the hydrocarbon fractions contain from 23 to 46 wt.% Of C ₆ hydrocarbons (benzene forms part of the feedstock for catalytic reforming purposes).

Table 2 shows the compositions of the olefinic fractions used in Examples 1-12. The olefin-containing fractions used can be considered, for example, as a model for a dry gas of catalytic cracking (the compositions of the SGCC were obtained by averaging the data of the refinery over several months of the catalytic cracking unit operation). However, we note that the name and the process of origin of the olefin-containing fractions may vary depending on the enterprise and the region. Attention should be paid to the chemical composition of the fraction used, in particular, the olefin-containing fraction should include C ₂ -C ₄ olefins in a total amount of 10 to 50 wt% and 0.5 to 8 wt% hydrogen H ₂ . Preferably, the weight fraction of C ₅₊ hydrocarbons in the olefin-containing fraction is not more than 5.0 wt%. Preferably, the volume fraction of hydrogen sulfide in the olefin-containing fraction is at most 0.005%. In particular cases, the olefin-containing fraction may contain from 2.3 to 8.0 wt% hydrogen.

Methanol technical grade "A" GOST 2222-95 was used as oxygenate in examples 1-3, 6-8 and 11-12. Examples 4 and 10 used dimethyl ether (DME), 99%. Examples 5 and 9 used 95% ethanol.

Table 3 shows the compositions of the zeolite catalysts used in examples 1-12.

Table 4 shows the conditions and basic parameters of examples 1-7. The hydrocarbon fraction in examples 1-7 is fed to the first reaction zone. Example 12 repeats the conditions of Example 1, except that in Example 12, the hydrocarbon fraction is distributed over three reaction zones in the ratio
60/30/10 wt%. The experiments were carried out at a pressure of 15-40 bar (1.5-4.0 MPa), preferably 22-27 bar (2.2-2.7 MPa). The parameter% substitution of oxygenate (percentage of substitution of oxygenates for olefin-containing fractions) is calculated using the formulas
(4) - (6) on pages 3-4 of this Description.

Table 5 and Table 8 show the composition of the liquid hydrocarbon product in Examples 1-7. Example 12 shows the yield of a liquid hydrocarbon product C _{5+ of} 75.6 wt.% Per fed hydrocarbon fraction at an RON of the product of 89.3 units. and an aromatic content of 28.2 wt% (data are given for a liquid hydrocarbon product that does not contain dissolved gases, similar to Table 5).

Table 8 shows the composition of gasoline after separation of gaseous products from it, while the content of dissolved gases in gasoline is stabilized at the level of 3-5 wt.% (stabilized liquid hydrocarbon product). Such a product can be considered as stable gasoline or as a high-octane base for the production of commercial gasolines. The products in Table 8 contain 3 to 5 wt% dissolved gases C_one-FROM_four... However, depending on the goals of a particular production, a liquid hydrocarbon product may contain different amounts of dissolved gases C_one-FROM_four... In particular, in the production of motor gasolines, the presence of up to 3-5 wt.% Of dissolved gases in summer gasolines and up to 5-7 wt.% Of dissolved gases in winter gasolines is usually allowed. The desired amount of dissolved gases in the product is controlled by standard fractionation and stabilization techniques.

Table 5 shows the composition of the products for the same experiments as Table 8, however, Table 5 shows the composition of liquid hydrocarbon products without dissolved gases C ₁ -C ₄ (C ₅₊ fraction of the hydrocarbon fraction of the product). Typically, production does not require a product that does not contain dissolved gases. However, a comparison of the yield and composition of C ₅₊ products is more revealing. Liquid hydrocarbon products obtained and stored under different conditions may contain different amounts of dissolved gases. In this case, the content of dissolved gases can vary unevenly over time, changing the chemical composition. This can lead to inadequate comparison of the yield and quality of products from different experiments, especially when comparing results from different enterprises. Therefore, it is more preferable to compare the parameters of a product that does not contain dissolved gases. However, we note that, depending on the goals of a particular production, the liquid hydrocarbon product may contain not only C ₅₊ hydrocarbons, but also different amounts of dissolved gases C ₁ -C ₄ , as shown in Table 8, for example.

Since C ₅₊ hydrocarbons (hydrocarbons with five or more carbon atoms) are the main component of a liquid hydrocarbon product, the yield of a liquid hydrocarbon product increases simultaneously with the yield of C ₅₊ hydrocarbons.

Table 6 shows the temperatures of the catalyst bed in the first, second and third reaction zones (R ₁₀₁ / R ₂₀₁ / R ₃₀₁ ), ° C.

Table 7 shows the conditions and basic parameters of examples 8-11. The hydrocarbon fraction in examples 8-11 is fed to the first reaction zone. The experiments were carried out at a pressure of 22-27 bar (2.2-2.7 MPa).

The gaseous product in examples 1-12 consisted mainly of saturated hydrocarbons and nitrogen. The source of nitrogen is the olefin-containing fractions fed to the reaction. In the examples according to the invention, the content in the gaseous product of hydrocarbons C ₃₊ (mainly propane) was 40-70 vol.%. The total content of olefins in the gaseous product was 0.6-1.1 vol.%, Which shows a high degree of conversion of olefins in the feed. The ethane content was 0.6–1.4 vol.%, Which indicates the suppression of side processes of ethylene hydrogenation with hydrogen in the feedstock.

Table 1. Composition of hydrocarbon fractions, wt%

Hydrocarbon fraction, wt% A B FROM D Description Mixture: 50 vol. % raffinate and 50 vol. % fr. 62-85 Gasoline gas stable Light gas condensate Straight-run fraction 65 ° С -.к ^** PIONA ^* , wt% 24, 42, 2, 31, 1 16, 47, 1, 34, 1 15, 42, 1, 40, 1 19, 56, 2, 22, 1 Hydrocarbons С ₁ -С ₄ 0.03 0.01 0.02 0.05 n-pentane 1.11 0.19 0.16 0.38 Normal paraffins C ₆₊ 23.23 16.26 15.20 18.75 Isopentane (OCHI 92) 0.42 0.05 0.04 0.10 С ₆ monomethyl (OCHI 76) 6.66 1.98 1.74 2.95 С ₆ dimethyls (OCHI 92-106) 0.70 0.33 0.26 0.59 C ₇ dimethyl (OCHI 94) 3.16 4.70 17.45 4.49 C ₇ monomethyl (OCHI 52) 23.17 31.27 17.02 33.29 C ₈₊ isoparaffins
(OCHI 10-69) ^*** 7.59 8.75 5.90 14.32 Olefins C ₅₊ 1.78 1.13 1.11 1.58 Cyclopentanes 17.12 17.56 19.97 12.62 Cyclohexanes 13.57 16.54 19.79 9.42 Benzene 1.18 0.71 0.89 0.37 Alkylbenzenes C ₇ -C ₁₁ 0.27 0.18 0.20 0.34 Aromatika C ₁₂₊ 0.01 - - 0.01 Unrecognized - 0.34 0.25 0.74 Total, wt% 100.00 100.00 100.00 100.00 incl. hydrocarbons С ₆ 46.11 36.44 43.37 23.40 incl. isoparaffins with RHI less than 70 30.76 40.02 22.92 47.61 ^* P (normal paraffins), I (isoparaffins), O (olefins), N (naphthenes), A (aromatics) ^, calculated from the detailed hydrocarbon composition and serves to quickly assess the composition of the fraction. Due to rounding to units, it may not add up to 100%.
^** Straight-run gasoline, c.c. - the end of boiling is undefined.
^*** Isoparaffins with three or more chains (RON more than 90) are contained in the used hydrocarbon fractions in trace amounts.

Table 2. Composition of olefin-containing fractions, wt%

Olefin-containing fraction, wt% A B C D Methane 0.0 4.7 38.5 22.1 Ethane 0.0 18.5 20.2 18.0 Ethylene 33.8 31.4 8.8 18.2 Propane 0.0 3.0 0.8 0.7 Propylene 0.0 13.5 0.7 3.5 Isobutane 0.0 3.2 0.8 0.7 n-Bhutan 0.0 0.9 0.4 0.5 The amount of butylenes (butene-1, butenes-2, isobutylene, butadiene) 0.0 5.1 0.5 2.3 The amount of hydrocarbons C ₅₊ 0.0 4.2 0.2 3.0 H ₂ 2.3 0.5 8.0 3.2 N ₂ 63.9 14.1 19.5 25.7 Unrecognized 0.0 0.9 1.6 2.1 Total: 100.0 100.0 100.0 100.0 incl. olefins 33.8 50.0 10.0 24.0 incl. hydrocarbons С ₁ -С ₂ 33.8 54.6 67.5 58.3

Table 3. The composition of the zeolite catalysts used in examples 1-12.

Indicator name Norm A B C Zeolite type - ZSM-5 ZSM-5 ZSM-5 Zeolite modulus, molar ratio SiO ₂ / Al ₂ O ₃ 43–95 77 43 95 Composition of zeolite catalysts, wt% High-silica zeolite of the pentasil group not less than 65 70 65 80 Sodium oxide no more than 0.15 0.08 0.15 0.04 Zinc oxide 1.0-5.5 2.0 1.0 5.5 The amount of oxides of rare earth elements * 0.5-5.0 1.6 5.0 0.5 Binder (SiO ₂ and / or Al ₂ O ₃ ) The rest is up to 100% The rest is up to 100% The rest is up to 100% The rest is up to 100% incl. mass fraction of silicon dioxide in terms of catalyst calcined at 550 ° C 55.0–80.0 69 55 80

* Rare earth elements (REEs) include, for example, lanthanum, praseodymium, neodymium, cerium, preferably mixtures thereof. The source of rare earth compounds can be individual compounds of each of the elements, for example, nitrates. Mixtures of rare earth compounds can also serve as a source of rare earth compounds. For example, as a source of compounds of rare earth elements, intermediates of the production of rare earth elements with a content of mixed REE compounds of at least 60 wt% can be used, such as a concentrate of rare earth elements, a rough rare earth concentrate of REE, collective concentrates of rare earth metals, intermediates of processing of rare earth ores. Mixtures of rare earth compounds can be used without prior separation of the individual rare earth compounds.

Table 4. Conditions and basic parameters of examples 1-7 ^***

Example no. one 2 3 four five 6 7
(cf.) Hydrocarbon fraction B B B A D FROM B Oxygenate methanol methanol methanol DME ethanol methanol methanol Olefin-containing fraction A A D B C A A Catalyst A A B FROM C A A Mass feed rate of raw materials, h-1 1.44 1.47 3.05 1.62 2.15 1.54 1.47 Total weight of catalyst, g 4713 4713 3089 4357 4357 4713 4713 Pressure, bar 22 22 fifteen 22 40 27 22 Raw material supply temperature, ◦С R ₁₀₁ ^* 350 350 340 360 360 380 350 R ₂₀₁ 350 350 360 360 360 380 350 R ₃₀₁ 350 350 350 360 360 380 350 % replacement of oxygenate by olefin-containing fraction 83.4 82.7 84.6 53.9 27.6 83.2 82.1 Oxygenate, distribution over reaction zones, wt% R ₁₀₁ 100 0 100 100 0 0 47 R ₂₀₁ 0 0 0 0 0 0 33 R ₃₀₁ 0 100 0 0 100 100 twenty Olefin-containing fraction, distribution over reaction zones, wt% R ₁₀₁ 0 36 0 0 45 25 22 R ₂₀₁ fifty 64 35 65 55 75 39 R ₃₀₁ fifty 0 65 35 0 0 39 Catalyst, distribution over reaction zones, wt% R ₁₀₁ 24 24 17 25 29 33.3 24 R ₂₀₁ 38 38 33 28 43 33.3 38 R ₃₀₁ 38 38 fifty 47 28 33.3 38 Raw material composition, wt% Hydrocarbon fraction 70.7 71.2 62.4 68.4 53.9 72.6 70.9 Oxygenate 3.9 4.0 3.1 11.9 13.4 3.7 4.2 Olefin-containing fraction 25.4 24.8 34.5 19.7 32.7 23.7 24.9 Total, wt% 100.0 100.0 100.0 100.0 100.0 100.0 100.0 Parameters of C _{5+ liquid hydrocarbon product} Liquid outlet u / w product, wt% ^** 72.8 75.3 75.2 71.2 70.1 73.2 67.4 OCHI liquid product 89.6 88.6 88.3 92.8 92.7 89.5 86.5

^* R _101, R _201, R ₃₀₁ - the first, second and third reaction zones.

^** Yield of С ₅₊ hydrocarbons per supplied hydrocarbon fraction.

^*** In experiments 1-7, the entire hydrocarbon fraction is distributed to the first reaction zone.

Table 5. The composition of the liquid hydrocarbon product containing no dissolved gases (product C ₅₊ ) in examples No. 1-7.

Total hydrocarbon composition, PIONA ^* , wt% one 2 3 four five 6 7
(cf.) P (n-paraffins) 10 10 10 7 7 eleven nine I (isoparaffins) 48 fifty 46 49 fifty 47 41 O (olefins) 3 3 one 3 3 2 3 N (naphthenes) 7 7 13 eight eight nine 12 A (aromatics) thirty 28 29 32 31 31 34 Unrecognized 2 2 one 2 one 2 one Total, wt% 100 100 100 100 100 100 100 Detailed hydrocarbon composition, wt% Hydrocarbons С ₁ -С ₄ 0.00 0.00 0.00 0.00 0.00 0.00 0.00 n-pentane 5.20 5.02 5.02 3.97 4.30 4.85 5.16 n-hexane 3.41 3.81 3.45 1.07 1.31 4.43 2.25 n-heptane 0.76 0.93 0.94 0.15 0.14 0.84 0.35 Normal paraffins C ₈₊ 0.41 0.40 0.28 1.62 1.55 0.42 0.88 Isopentane 7.04 6.59 6.36 9.09 8.00 6.36 8.20 Isoparaffins C ₆ 8.25 8.10 6.41 5.80 7.16 6.13 7.82 Isoparaffins C ₇ 25.86 27.81 25.83 27.20 27.72 28.70 17.98 Isoparaffins C ₈₊ 6.77 7.98 7.31 7.00 6.77 5.44 7.16 Olefins C ₅₊ 3.15 2.66 1.45 2.70 3.10 1.72 2.91 Cyclopentanes 5.10 5.24 10.58 5.88 5.72 5.22 8.66 Cyclohexanes 1.71 1.84 2.77 2.27 2.03 3.78 2.97 Aromatics 30.35 27.89 28.76 31.66 30.77 30.54 34.49 Unrecognized 1.99 1.73 0.84 1.59 1.43 1.57 1.17 Total, wt% 100.00 100.00 100.00 100.00 100.00 100.00 100.00 incl. isoparaffins with OCHI ^** more than 70 units, wt% 29.8 30.4 29.7 32.6 33.8 30.1 21.6 incl. benzene 1.57 1.41 1.33 1.40 1.51 1.54 1.97 the proportion of benzene in relation to the total aromatics,% 5.19 5.05 4.73 4.48 4.90 5.04 5.72

^* P (normal paraffins), I (isoparaffins), O (olefins), N (naphthenes), A (aromatics), calculated from the detailed hydrocarbon composition and serves to quickly assess the composition of the fraction. Due to rounding to units, it may not add up to 100%.

** Research octane numbers according to Ind. Eng. Chem. Res. 2006, 45, 1, 337-345. In particular, for isoparaffins: isopentane (OCHI 92), C ₆ monomethyl (OCHI 76), C ₆ dimethyl (OCHI 92-106), C ₇ dimethyl (OCHI 94), isoparaffins C ₈₊ (OCHI 10-69), at subject to trace amounts of isoparaffins with three or more side chains.

Table 6. Temperatures of the catalyst layer in the first, second and third reaction zones (R ₁₀₁ / R ₂₀₁ / R ₃₀₁ ), ° C.

Example no. one 2 3 four five 6 Raw material supply temperature, T_in, ° С R ₁₀₁ 350 350 340 360 360 380 R ₂₀₁ 350 350 360 360 360 380 R ₃₀₁ 350 350 350 360 360 380 Maximum temperature of the catalyst layer, T_max, ° С R ₁₀₁ 373 369 380 393 400 443 R ₂₀₁ 392 408 389 408 405 392 R ₃₀₁ 395 381 395 398 393 386 Temperature at the end of the catalyst layer, T_out, ° С R ₁₀₁ 373 365 374 388 392 441 R ₂₀₁ 392 402 388 405 400 382 R ₃₀₁ 382 377 393 397 392 374 Heating up along the catalyst bed, T_max - T_in, ° С R ₁₀₁ 23 nineteen 40 33 40 63 R ₂₀₁ 42 58 29 48 45 12 R ₃₀₁ 45 31 45 38 33 6 Temperature drop over the catalyst bed, T_max - T_out, ° С R ₁₀₁ 0 four 6 five eight 2 R ₂₀₁ 0 6 one 3 five 10 R ₃₀₁ 13 four 2 one one 12

Table 7. Conditions and main parameters of a liquid hydrocarbon product that does not contain dissolved gases (product C ₅₊ ) in examples No. 8-11 ^***

Example no. eight nine 10 eleven Hydrocarbon fraction B D C A Oxygenate methanol ethanol DME methanol Olefin-containing fraction A C D A Catalyst A B C A Mass feed rate of raw materials, h ^-1 0.9 1.2 0.7 0.3 Total weight of catalyst, g 4713 3089 4357 4713 Pressure, bar 22 22 40 27 Raw material supply temperature, ◦С R ₁₀₁ 390 390 410 370 R ₂₀₁ 390 400 420 370 R ₃₀₁ 390 400 430 370 % replacement of oxygenate by olefin-containing fraction 83.4 27.6 79.9 65.3 Oxygenate, distribution over reaction zones, wt% R ₁₀₁ 100 100 0 0 R ₂₀₁ 0 0 0 0 R ₃₀₁ 0 0 100 100 Olefin-containing fraction, distribution over reaction zones, wt% R ₁₀₁ 0 0 45 25 R ₂₀₁ 35 65 55 75 R ₃₀₁ 65 35 0 0 Catalyst, distribution over reaction zones, wt% R ₁₀₁ 24 17 29 24 R ₂₀₁ 38 33 43 38 R ₃₀₁ 38 fifty 28 38 Raw material composition, wt% Hydrocarbon fraction 70.7 53.9 62.4 53.9 Oxygenate 3.9 13.4 3.1 13.4 Olefin-containing fraction 25.4 32.7 34.5 32.7 Total, wt% 100 100 100 100 Key process indicators Liquid outlet u / w product, wt% ^** 56.7 56 65.9 65.6 OCHI liquid product 98 97.8 98.4 98.4 Fraction of aromatics, wt% 56.8 57.8 53.3 51 The proportion of benzene, wt% 3.7 3.1 3.8 2.6 The share of aromatic u / in C ₈ wt.,% 17.9 18.6 16.5 16.2 the proportion of C ₈ aromatics in relation to the total aromatics,% 31.5 32.2 31 31.8

^** Yield of С ₅₊ hydrocarbons per supplied hydrocarbon fraction.

^*** In experiments 8-11, the entire hydrocarbon fraction is distributed to the first reaction zone

Table 8. The composition of the stabilized liquid hydrocarbon product in examples No. 1-7.

Detailed hydrocarbon composition, wt% one 2 3 four five 6 7
(cf.) Hydrocarbons С ₁ -С ₄ 3.6 4.5 4.8 3.0 4.2 4.6 4.4 n-pentane 5.0 4.8 4.8 3.9 4.1 4.6 4.9 n-hexane 3.3 3.6 3.3 1.0 1.3 4.2 2.2 n-heptane 0.7 0.9 0.9 0.1 0.1 0.8 0.3 Normal paraffins C ₈₊ 0.4 0.4 0.3 1.6 1.5 0.4 0.8 Isopentane 6.8 6.3 6.1 8.8 7.7 6.1 7.8 Isoparaffins C ₆ 8.0 7.7 6.1 5.6 6.9 5.8 7.5 Isoparaffins C ₇ 24.9 26.6 24.6 26.4 26.6 27.4 17.2 Isoparaffins C ₈₊ 6.5 7.6 7.0 6.8 6.5 5.2 6.8 Olefins C ₅₊ 3.0 2.5 1.4 2.6 3.0 1.6 2.8 Cyclopentanes 4.9 5.0 10.1 5.7 5.5 5.0 8.3 Cyclohexanes 1.6 1.8 2.6 2.2 1.9 3.6 2.8 Aromatics 29.3 26.6 27.4 30.7 29.5 29.1 33.0 Unrecognized 2.0 1.7 0.6 1.6 1.2 1.6 1.2 Total, wt% 100.0 100.0 100.0 100.0 100.0 100.0 100.0 incl. isoparaffins with OCHI ^* more than 70 units, wt% 28.7 29.0 28.3 31.6 32.4 28.7 20.6 incl. benzene 1.5 1.3 1.3 1.4 1.4 1.5 1.9 Product yield ^* , wt% 75.5 78.8 79.0 73.4 73.2 76.7 70.5

^* Research octane numbers according to Ind. Eng. Chem. Res. 2006, 45, 1, 337-345. In particular, for isoparaffins: isopentane (OCHI 92), C ₆ monomethyl (OCHI 76), C ₆ dimethyl (OCHI 92-106), C ₇ dimethyl (OCHI 94), isoparaffins C ₈₊ (OCHI 10-69), at subject to trace amounts of isoparaffins with three or more side chains.

^** Output of stabilized liquid hydrocarbon product (stable gasoline after separation of the gaseous product) to the supplied hydrocarbon fraction.

Observations

Increasing the yield of liquid hydrocarbon product

It has been found that when producing gasolines, the proposed method makes it possible to increase the yield of a liquid hydrocarbon product per supplied hydrocarbon fraction. Examples 1-6 demonstrate an increase in the yield of liquid hydrocarbon product by 3-8 wt.% In comparison with comparative example 7. At the same time, the octane number of the product according to the research method is higher than 88 units. This effect can be explained by a decrease in the conversion of high-octane isoparaffins of the feedstock while maintaining a high level of conversion of n-paraffins.

Reducing the proportion of benzene in a liquid hydrocarbon product

It was found that when producing gasolines, the proposed method makes it possible to reduce the proportion of benzene in the liquid hydrocarbon product. As examples 1-6 demonstrate, when all the oxygenate is fed either to the first reaction zone or to the last reaction zone, the proportion of benzene to total aromatics decreases (reduction from 6 to 4-5 rel.%). At the same time, the benzene content in the liquid hydrocarbon product is reduced to less than 1.6 wt%. This result is achieved even in the case when C ₆ hydrocarbons make up more than a third of the composition of the hydrocarbon fraction of the feed _. In particular, the AC hydrocarbon fractions used contained 36 to 46 wt% C ₆ hydrocarbons. C ₆ hydrocarbons are precursors of benzene in known catalytic processes for the production of gasolines. Conversion of the hydrocarbon fraction with a high content of benzene precursors by known methods will result in a product with a high benzene content. Such a product is difficult to use when compounding motor gasolines, where the maximum benzene content is strictly limited. In particular, the catalytic reforming of a hydrocarbon fraction containing 36-46 wt% C ₆ hydrocarbons will lead to a product with a benzene content of 5-10 wt%, which is significantly higher than the results of the proposed method.

An increase in the content of highly branched isoparaffins in the product, mainly due to an increase in the formation of C _{7 isoparaffins}

Found that the proposed method allows you to increase the content of highly branched isoparaffins (isoparaffins with two or more side chains) in the product. This result is achieved mainly due to the increase in the formation of isoparaffins C _7. As examples 1-6 and 8-11 show, due to the high individual RON of such isoparaffins, RON of the liquid hydrocarbon product is kept at a level above 88 points, while increasing the yield of the target product. Separate feeding of oxygenates and olefin-containing fractions markedly increases the content of isoparaffins with an octane number of more than 70 units. in the product (by 8 - 12 wt.%).

Improved selectivity for C _{9 alkylbenzenes}

In examples 1-6 and 8-11, the proposed method allows you to increase the selectivity of the formation of alkylbenzenes C ₉ from 5 to 6-7 wt.%. Alkylbenzenes C ₉ have extremely high RON (on average 110 units), which makes them attractive components for the compounding of high-octane gasolines.

Ability to eliminate the recycling of gaseous products

Found that the proposed method eliminates the recycle of gaseous products. All examples according to the proposed method show the conversion of olefins C ₂ -C ₄ raw materials above 98 wt.%. Such a high degree of conversion in one pass of the feedstock through the reactor makes it possible to abandon the use of the recycle of gaseous products for the purpose of a more complete processing of the olefins of the feedstock.

Possibility to use low-demand olefin-containing fractions with a high hydrogen content as raw material without additional separation

It was found that the proposed method allows the use of low-margin olefin-containing fractions with a high hydrogen content as raw material and without additional separation. Examples 1-6 and 8-12 use olefin-containing fractions with a hydrogen content of 0.5 to 8 wt.%, Without preliminary separation of hydrogen from them. Fuel gases of various origins often contain C ₂ -C ₄ olefins necessary for the processing process simultaneously with significant amounts of hydrogen. The presence of hydrogen in the olefin source can lead to side reactions. In particular, olefins can be hydrogenated instead of participating in the alkylation of the aromatics produced. The proposed process allows the use of such olefin-containing fractions without preliminary separation of hydrogen from them. This expands the range of hydrogen sources that can be used as a substitute for oxygenates.

As a technical result, the possibility of using little-demanded olefin-containing fractions as raw materials for the production of gasolines or concentrates of aromatic compounds is also being considered. Refineries produce olefin-containing fractions that are used as fuel. These are gases from catalytic cracking, gases from a delayed coking unit, olefin-containing fuel gases of various origins, etc. The content and composition of olefins in such streams is too low for commercially viable recovery. At the same time, the cost of streams burned as fuel is minimal. The involvement of such olefin-containing fractions in the production of gasoline significantly increases the value of the stream for the enterprise.

Possibility of partial replacement of oxygenate with olefin-containing fractions

As a technical result, the possibility of partial replacement of oxygenate with olefin-containing fractions is also considered. This approach allows you to reduce the consumption of oxygenates while maintaining the yield and quality of the product.

In examples 1-6 and 8-12 olefin-containing fractions of the feed act as a partial replacement for oxygenates of the feed. Co-processing of hydrocarbon fractions and oxygenates (without the involvement of olefin-containing fractions) often makes it possible to obtain gasolines with high RON and high product yields. However, oxygenates such as methanol, ethanol, dimethyl ether are rarely available in refineries as cheap feedstocks. When the source of oxygenate cannot be found in the by-product or intermediate product of the enterprise itself, it has to be purchased from outside at the prices of the commercial product. This increases the cost of producing a unit of commercial gasoline, and complicates the production logistics.

At the same time, the proposed method makes it possible to partially replace oxygenates with a source of dilute olefins (olefin-containing fractions). The proposed method allows the use of diluted olefins instead of highly concentrated sources of olefins (eg, pure ethylene). This creates an opportunity as a source of olefins, semi-products and by-products of already existing petrochemical plants. Among them are dry catalytic cracking gases, various fuel gases with an olefin content of 10 to 50 wt%.

The calculation of the percentage of substitution of oxygenates for olefin-containing fractions is carried out according to formulas (4) - (6) on page 3 of this Description. The examples according to the invention show the possibility of replacing from 28 to 85% of oxygenate with olefin-containing fractions with obtaining a RON of liquid hydrocarbon product above 88 units.

The provided formulas (4) - (6) can be applied to the already known methods of joint processing of hydrocarbon fractions and oxygenates (without involving olefin-containing fractions) into gasolines. In this case, formulas (4) - (6) make it possible to calculate the amount (molar flow, mol / h) of oxygenate in a known method, which can be replaced by available olefin-containing fractions without loss of quality and product yield.

Minimum drop in catalyst bed temperature without using internal heat exchangers

Found that in examples 1-6 and 8-12 according to the proposed method, the temperature of the end layer of the catalyst is not more than 15 ° C below the maximum temperature of the catalyst layer in each reaction zone. In particular, Table 6 shows the catalyst bed temperatures reached in Examples 1-6. This reduces the likelihood of uneven coking of the catalyst, as well as the likelihood of side reactions (for example, oligomerization of olefins instead of involving them in the alkylation of aromatics).

The proposed method makes it possible to achieve this result without using reactors with built-in heat exchangers (isothermal reactors, tubular reactors, etc.). The use of isothermal reactors in laboratory experiments often makes it possible to keep the temperature of the catalyst bed in a narrow range. However, the use of isothermal reactors in industry is difficult to justify from an economic point of view. Built-in heat exchangers add to the cost of manufacturing and maintaining reactor equipment. Therefore, it is important that the proposed method allows you to maintain a minimum temperature difference across the catalyst bed without the use of built-in heat exchangers.

Lack of oxygenates in the liquid hydrocarbon product

The proposed method makes it possible to obtain a liquid hydrocarbon product that does not contain oxygenates. Oxygenates, especially ethanol, are often used as octane-increasing additives in the compounding of motor gasolines. However, the maximum content of oxygenates in commercial gasolines is strictly standardized. Liquid hydrocarbon products obtained in examples 1-6 and 8-12 do not contain oxygenates, but have a high octane number according to the research method (RON of the product is more than 88 units). This combination of properties allows the use of the maximum allowable amount of oxygenates when compounding commercial gasolines based on the product obtained by the proposed method.

Possibility of producing low-benzene aromatics concentrates

When obtaining concentrates of aromatic compounds , the possibility of producing low-benzene aromatic concentrates is considered as an additional technical result. There are several classical methods for obtaining FAU (fractions of aromatic hydrocarbons, they are also a concentrate of aromatic hydrocarbons). Aromatic concentrates can be obtained, for example, during catalytic reforming, or as by-products of refining. The resulting aromatic concentrates can be used as a high-octane base for compounding motor gasolines. Unfortunately, known methods often lead to the production of an aromatic concentrate with an extremely high proportion of benzene (benzene content in the liquid hydrocarbon product is more than 15 wt%). The high content of benzene in aromatics concentrate sharply limits its use when mixing motor gasolines, because The maximum benzene content in fuels is strictly controlled.

However, the proposed method for obtaining concentrates of aromatic compounds makes it possible to obtain low-benzene FAU (fractions of aromatic compounds). Obtained in examples 8-11, the liquid hydrocarbon product contains 56-66 wt.% Aromatic hydrocarbons. In this case, the benzene content is 3 - 4 wt.%. Thus, the proposed method makes it possible to obtain FAA with a significantly lower benzene content in comparison with classical methods.

Possibility of producing aromatic concentrate with a high content of aromatic hydrocarbons C ₈

When obtaining concentrates of aromatic compounds , the possibility of producing aromatic concentrates with an increased content of C ₈ alkylbenzenes is considered as an additional technical result. Examples 8-11 demonstrate that the proposed method makes it possible to achieve the content of C ₈ alkylbenzenes in the liquid hydrocarbon product from 16 to 19 wt.%. In this case, the proportion of C ₈ aromatics in relation to the total aromatics reaches 31-32 rel. % Average RON of C ₈ alkylbenzenes reaches 112 units, which makes them attractive components for compounding high-octane gasolines.

Distributed supply of hydrocarbon fraction

It was noticed that changing the feed of the hydrocarbon fraction to the reaction zones makes it possible to control several parameters of the process. In particular, the distribution of the hydrocarbon fraction into two or three reaction zones makes it possible to further increase the yield and / or selectivity of the formation of C ₅₊ hydrocarbons (hydrocarbons with five or more carbon atoms). Also, in the case of distributed feeding of the hydrocarbon fraction to several reaction zones, cracking of isoparaffins with two or more alkyl substituents with the formation of lower hydrocarbons C ₁ -C ₄ can be suppressed. Also, as a result of the distribution of the hydrocarbon fraction into several reaction zones, a decrease in the dealkylation of alkylaromatic hydrocarbons can be observed.

In particular, Example 12 shows the possibility of distributing the hydrocarbon fraction over several reaction zones. Example 12 repeats the conditions of Example 1, except for a change in the distribution of the hydrocarbon fraction. In example 1, the distribution of the hydrocarbon fraction over the reaction zones R ₁₀₁ / R ₂₀₁ / R ₃₀₁ was 100/0/0 wt%. Example 12 maintains the same mass flow rates as Example 1, however, the hydrocarbon fraction is distributed over the three reaction zones in a ratio of 60/30/10 wt.%. As a result, it is possible to increase the product yield by 3 wt% per supplied hydrocarbon fraction (from 72.8 to 75.6 wt% for a liquid hydrocarbon product that does not contain dissolved gases).

The aromatics content in the product of Example 12 (liquid hydrocarbon product, free of dissolved gases C ₁ -C ₄ ) is reduced by 2.2 wt.% Compared to example 1 (from 30.4 to 28.2 wt.%). Typically, as the concentration of aromatics in the product decreases, the octane rating of the product is expected to decrease. However, it was found that the RHI of the product of Example 12 is practically indistinguishable from the RTI of the product of Example 1 (89.6 and 89.3 units, respectively). This effect can be explained by a decrease in the cracking of high-octane C ₅ -C ₈ isoparaffins (isoparaffins with individual research octane numbers more than 72 units) as a result of the distributed supply of the hydrocarbon fraction to several reaction zones.

It is also possible, if necessary, to distribute the entire flow of the hydrocarbon fraction only to the second or only to the third reaction zone.

Claims (42)

1. A method for producing a liquid hydrocarbon product containing aromatic compounds, in which three streams are used as raw materials, the first of which includes a hydrocarbon fraction, the second stream includes an oxygenate, the third stream includes an olefin-containing fraction, three reaction zones filled with a zeolite catalyst are used, the product stream from the first reaction zone is fed to the second reaction zone, and the product stream from the second reaction zone is fed to the third reaction zone, wherein: a. the olefin-containing fraction includes one or more olefins selected from the group consisting of ethylene, propylene, normal butylenes, isobutylene, in a total amount of 10 to 50 wt%, and contains 0.5 to 8 wt% hydrogen, b. the first stream is fed to at least one reaction zone, c. the second stream is fed to the first reaction zone or to the third reaction zone, d. wherein the third stream is fed into the second and third reaction zones when the second stream is fed into the first reaction zone, or into the first and second reaction zones when the second stream is fed into the third reaction zone, e. moreover, when the second stream is fed into the first zone, the distribution of the third stream between the two reaction zones is 35-65 wt% / 65-35 wt%, f. and when the second stream is fed to the third reaction zone, the distribution of the third stream between the two reaction zones is 25-45 wt% / 75-55 wt%. 2. The method according to claim 1, wherein the liquid hydrocarbon product containing aromatic compounds is gasoline if the content of aromatic compounds is less than 40 wt%, or the liquid hydrocarbon product containing aromatic compounds is an aromatic concentrate if the content of aromatic compounds is compounds is more than 40 wt.%. 3. A process according to claim 1, wherein the first stream is preferably fed to the first reaction zone. 4. The method according to claim 1, in which the hydrocarbon fraction contains normal paraffins in the amount of 15-24 wt.%, Isoparaffins in the amount of 42-56 wt.%, Naphthenes in the amount of 22-40 wt.%, The rest is aromatic hydrocarbons and olefins ... 5. The method according to claim 1, in which the hydrocarbon fraction can be selected from the group consisting of straight-run gasoline, gas stable gasoline, light gas condensate, gasoline fraction with boiling points of about 62 ° - 85 ° C, raffinate, and mixtures thereof. 6. A process according to claim 1, wherein the hydrocarbon fraction contains 0 to 80 wt% C ₆ hydrocarbons, preferably 23 to 46 wt% C ₆ hydrocarbons, most preferably 36 to 46 wt% C ₆ hydrocarbons. 7. A process according to claim 1, wherein the hydrocarbon fraction contains 0 to 70 wt% C ₇ isoparaffins, preferably 26 to 50 wt% C ₇ isoparaffins, most preferably 26 to 38 wt% C ₇ isoparaffins. 8. The method according to claim 1, in which the oxygenate is selected from the group consisting of aliphatic alcohols, for example, methanol, ethanol, crude methanol, technical methanol, ethanol; ethers, for example, dimethyl ether, as well as mixtures thereof, including with water. 9. A process according to claim 1, wherein the oxygenate may contain impurities, for example, aldehydes, carboxylic acids, esters, unsaturated alcohols. 10. The process according to claim 1, wherein the olefin-containing fraction is selected from the group consisting of products of fractionation of catalytic cracking gases, dry catalytic cracking gas, catalytic cracking wet gas, coking offgas, Fischer-Tropsch synthesis gases, thermal cracking gas, visbreaking gas, hydrocracking waste gases, pyrolysis gas, catalytic reforming waste gases, and mixtures thereof. 11. The method of claim 1, wherein the olefin-containing fraction may include non-olefinic hydrocarbon components, for example, methane, ethane, propane, butane, and may contain inorganic gases, for example, nitrogen. 12. The method of claim 1, wherein the olefin-containing fraction comprises
2.3-8.0 wt% hydrogen, preferably 3.2-8.0 wt% hydrogen. 13. A process according to claim 1, wherein the weight fraction of C ₅₊ hydrocarbons in the first olefin-containing fraction is from 0 to 10.0 wt%, preferably from 0 to 5.0 wt%. 14. A process according to claim 1, wherein the olefin-containing fraction may comprise C ₅₊ olefins, eg, pentenes, hexenes. 15. The method according to claim 1, wherein the volume fraction of hydrogen sulfide in the olefin-containing fraction is from 0.0 to 0.005%. 16. The method of claim 1, wherein the olefin-containing fraction comprises dry catalytic cracking gas and contains 25 to 40 wt% C ₂ -C ₄ olefins. 17. A method according to claim 1, wherein the process pressure is between 1.5 and 4.0 MPa, preferably between 2.2 and 2.7 MPa. 18. The method according to claim 1, wherein the temperature of the stream at the inlet to the first / second / third reaction zone is 340-450 ° C / 350-450 ° C / 350-450 ° C. 19. The method according to claim 1, wherein the mass feed rate of the feed is 0.5 to 10 h ^-1 , preferably 1-3 h ^-1 . 20. The method according to claim 1, wherein the temperature of the stream at the inlet to the first / second / third reaction zone is 340-380 ° C / 350-380 ° C / 350-380 ° C. 21. The method according to claim 1, wherein the mass feed rate of the feed is 0.9 to 10 h ^-1 , preferably 1-3 h ^-1 . 22. The method according to claim 1, wherein the temperature of the stream at the inlet to the first / second / third reaction zone is 390-450 ° C / 390-450 ° C / 390-450 ° C. 23. The method according to claim 1, in which the mass feed rate of the raw material is from 0.1 to 0.9 h ^-1 . 24. The method according to claim 1, in which the distribution of the catalyst over the reaction zones is 15-35 wt.% / 25-45 wt.% / 25-60 wt.% Of the total amount of catalyst for the first / second / third reaction zone, respectively, preferably 17-33 wt.% / 28-43 wt.% / 28-50 wt.% Of the total amount of the catalyst. 25. A process according to claim 1, wherein the hydrocarbon fraction comprises 50-85 wt% of the feedstock feed, preferably 54-73 wt% of the feedstock feed. 26. A process according to claim 1, wherein the olefin-containing fraction is 20-35 wt.% Of the feed. 27. A process according to claim 1, wherein the oxygenate comprises 3-14 wt% of the feedstock feed. 28. The method of claim 1, wherein the zeolite catalyst comprises: a. zeolite of the ZSM-5 type with a SiO ₂ / Al ₂ O ₃ modulus from 43 to 95 in an amount from 65 to 80 wt%, b. sodium oxide in an amount from 0.04 to 0.15 wt%, c. zinc oxide in an amount of 1.0–5.5 wt%, d. oxides of rare earth elements in a total amount of 0.5–5.0 wt%, e. a binder comprising silicon dioxide, aluminum oxide, or mixtures thereof. 29. The method of claim 28, wherein the zeolite catalyst is free of platinum metals. 30. The method of claim 28, wherein the rare earths are selected from the group consisting of lanthanum, praseodymium, neodymium, cerium, and mixtures thereof. 31. The method of claim 1, wherein the reaction is carried out in the gas phase in a fixed bed of catalyst.