WO2022005334A1

WO2022005334A1 - Method for increasing the yield of a liquid hydrocarbon product

Info

Publication number: WO2022005334A1
Application number: PCT/RU2021/050180
Authority: WO
Inventors: Владимир Владиславович ИМШЕНЕЦКИЙ; Иосиф Израилевич ЛИЩИНЕР; Ольга Васильевна МАЛОВА; Денис Васильевич ПЧЕЛИНЦЕВ; Андрей Леонидович ТАРАСОВ; Александр Анатольевич БЕССОНОВ; Дмитрий Валерьевич ИВАНОВ; Елена Николаевна ЛОБИЧЕНКО
Original assignee: Общество С Ограниченной Ответственностью "Новые Газовые Технологии-Синтез"; Акционерное общество "Газпромнефть-Омский НПЗ"
Priority date: 2020-06-29
Filing date: 2021-06-22
Publication date: 2022-01-06
Also published as: CU20220076A7; RU2747864C1

Abstract

The invention relates to a method for increasing the yield of a liquid hydrocarbon product in a method for producing gasolines, in which three streams of feedstock are used, the first stream containing a hydrocarbon fraction, the second stream containing an oxygenate, and the third stream containing an olefin-containing fraction, wherein the olefin-containing fraction contains С₂-С₄ olefins in a total amount of from 10 to 50 wt%, and in which three reaction zones are used which are filled with a zeolite catalyst, the first stream being fed into at least one reaction zone, and the second and third streams being distributed into three reaction zones, wherein the temperature at the inlet of each subsequent reaction zone is higher than the temperature at the inlet of each preceding zone. Using the proposed method makes it possible to achieve approximately identical heating in each of the reaction zones without the use of built-in heat exchange equipment and to increase the yield of liquid product (by 3-7 wt%). Moreover, the resulting product has an octane rating of more than 90 and a benzene content of less than 1.2 wt%.

Description

METHOD FOR INCREASING THE OUTPUT OF LIQUID HYDROCARBON PRODUCT

The invention relates to the field of oil refining and petrochemical industries. More specifically, the invention relates to a method for increasing the yield of a liquid hydrocarbon product in a gasoline production process 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 this or that region or organization. For example, the end-boiling point of gasoline may exceed 215 ^° C. As another example, the benzene content of produced gasoline may exceed 1.0 vol. %. As another example, the aromatic content of the gasoline produced can 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, raw methanol, technical methanol, ethanol, dimethyl ether, other aliphatic alcohols, other ethers, as well as mixtures thereof, incl. 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 - fraction including May 10-50. % C2-C4 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 from 0.5 to 8.0 wt. % hydrogen, preferably from 2 to 8 May. % hydrogen. The olefin-containing fraction may not contain hydrogen (the hydrogen content is below the sensitivity of the determination method). Preferably, the mass fraction of Cs ₊ 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 located in a separate reactor. A separate reactor can be used as the reaction zone.

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

Cn - hydrocarbons with the number of carbon atoms n.

С „+ - 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.

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: input - (1)

_Cat where /; ^ВХ0Д - mass flow of the i-ro 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 entered the reaction to the amount of raw material fed into the reaction. For example, the conversion of the i-ro component:

where /; ^ВХ0Д - mass flow of the i-ro component at the inlet, g / h. gout ^o d _ _Macc0BbI g output stream of the i-th component, 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: f yield

where / _j ^BbIX ° ^rt is the mass flow of the i-th component at the outlet, g / h, if _i ^d is the total mass flow of all produced hydrocarbons, g / h.

The percentage of oxygenate substitution for the olefin-containing fraction (% substitution) is calculated as follows: n _/ 1 - substitutions = 1 1 ₁ Sί K - - = - ₇ - ^P ί oxygenate \

% = - I - _l 1 _l 0 _l 0 _p % _/ ,

_\ Ί ^'oxygenate' 2 j ^ olefin / (4) where u _of u k _with n _e _and m - molar flow of i-th oxygenate feed, mol / hr, k - the coefficient of i-th advising the feed oxygenate. The k factor is 0.5 for methanol, 1 for other oxygenates (eg ethanol, propanol, DME).

Ti _{j olefin} - molar flow of the j -th supplied 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:

% replacement

where and _{methanol mol} / _{h -} molar flow of supplied methanol, mol / h, ^p ethylene, mol / h - 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.

where _{ethanol is the} molar flow of supplied methanol, mol / h, n _p and _le is the molar flow of supplied ethylene, mol / h,

Pp _ro p _le n - molar flow of supplied propylene, mol / h,

Pd _y ti _les us ^_ total molar flow fed butylene (including isobutylene), mol / h

1 - coefficient for ethanol.

The percent substitution of the oxygenate for the olefin-containing fraction does not take into account the water supplied to the reaction zones. LEVEL OF TECHNOLOGY

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

Patent RU 2671568 dated 09/27/2016 refers to a complex plant for processing a mixture of Ci-Ciu hydrocarbons of various compositions (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 C2-C10 and / or their mixtures with each other, and / or with paraffins Ci-Ciu, and / or with hydrogen) in the presence of oxygen-containing compounds, including one or more parallel located sectioned adiabatic reactors, consisting of one or more stationary layers (sections) of a zeolite-containing catalyst with a supply or removal of heat between the layers (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 gasoline production.

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 plant 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 the invention WO2017155431 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 by means of 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 can be considered the fact that when obtaining gasoline, the temperature of the end layer of the catalyst is 40-70 ° C lower than the maximum temperature of the catalyst layer. Such a drop in temperature in the end layer of the catalyst can lead to uneven coking of the catalyst and to the occurrence of side reactions (for example, oligomerization of olefins instead of involving them in the processes of aromatic alkylation and aromatics formation).

As a disadvantage of the method, the need for additional heat supply to the reaction zones can also 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.

But none of the described documents investigates how the combination of the distribution of feedstock (both oxygenate and olefin-containing fraction) between the reaction zones and an increase in the temperature at the inlet of the reaction zone from stage to stage (the temperature at the inlet of each subsequent zones above the previous inlet temperature). Also known documents do not take into account the problems encountered when replacing pure olefins with cheap dilute sources of C2-C4 olefins. Conditions are not disclosed that allow obtaining a high-octane product under conditions when the feedstock includes methane, ethane, hydrogen, nitrogen. 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

The following are considered as the main technical results of the invention:

1. increase in the yield of liquid hydrocarbon product by May 3 - 7. % for the supplied hydrocarbon raw materials;

2.increase in the selectivity of the formation of С 5 ₊ hydrocarbons (selectivity of 46-49 wt.% Is achieved):

3. Achievement of approximately the same temperature heating in each reaction zone (the difference between the temperature heating does not exceed 10 ° C, preferably does not exceed 5 ° C). This avoids the use of built-in heat exchangers (for example, it is possible to avoid the use of tubular reactors). The temperature heating in the reaction zone is understood as the difference between the maximum temperature of the catalyst layer in the reaction zone and the temperature of the feed to this reaction zone;

4. the possibility of obtaining high-octane gasoline (OCHI liquid hydrocarbon product more than 90 units);

5. obtaining a product with a low benzene content (no more than 1.2 wt.%);

6. the ability to exclude the recycle of gaseous products through the catalytic bed;

7. reduction of oxygenate consumption due to partial replacement of oxygenate with olefin-containing fractions.

As a technical result, the possibility of using little-demanded olefin-containing fractions as feedstock for the production of gasoline 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, etc. The content and composition of olefins in such streams is too low to be commercially viable. 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.

The above technical results are achieved due to the proposed method for increasing the yield of a liquid hydrocarbon product and / or the selectivity of the formation of Cs ₊ hydrocarbons in a method for producing gasolines, in which three streams are used as feedstock, the first of which includes a hydrocarbon fraction, the second stream includes oxygenate, and the third stream includes an olefin-containing fraction, where: 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 May. %,

B. use three reaction zones filled with zeolite catalyst, c. the first stream is fed to at least one reaction zone, d. the second stream is partitioned into three reaction zones, e. the third stream is distributed into three reaction zones, f. 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, g. moreover, the temperature at the inlet of each subsequent reaction zone is higher than the temperature at the inlet of each previous zone.

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

Possible execution of the invention, in which the hydrocarbon fraction contains normal paraffins in the amount of 15-24 May. %, isoparaffins in the amount of 42-56 May. %, naphthenes in the amount of May 22-40. %, the rest is aromatic hydrocarbons and olefins.

Possible execution of the invention, in which the hydrocarbon fraction contains from 0 to 80 May. % hydrocarbons C _b , preferably from 23 to 46 May. % C _b hydrocarbons, most preferably from 36 to 46 May. % hydrocarbons C _b .

Possible execution of the invention, in which the hydrocarbon fraction contains from 0 to 70 May. % C7 isoparaffins, preferably from 26 to 50 May. % C7 isoparaffins, most preferably from 26 to 38 May. % C7 isoparaffins.

It is possible to carry out 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.

It is possible to carry out the invention in which the oxygenate is selected from the group consisting of aliphatic alcohols and ethers, for example, methanol, ethanol, crude methanol, technical methanol, 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. Possible execution of the invention, in which the olefin-containing fraction, the olefin-containing fraction includes 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 Cs ₊ hydrocarbons in the olefin-containing fraction is from 0 to 10.0 wt%. %, preferably from 0 to 5.0 May. %.

It is possible to carry out the invention, in which the volume fraction of hydrogen sulfide in the olefin-containing fraction is not more than 0.005%.

An embodiment of the invention is possible, in which the first olefin-containing fraction may include non-olefinic hydrocarbon components, for example, methane, ethane, propane, butane, may contain inorganic gases, for example, hydrogen, nitrogen, may contain impurities of heavier Cs ₊ olefins, for example, pentenes, hexenes.

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

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

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 .

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 330-350 ° C / 340-360 ° C / 350-370 ° C, preferably 335-345 ° C / 345-355 ° C / 355-365 ° C.

An embodiment of the invention is possible, in which the distribution of the second stream between the three reaction zones is 40-60 May. % / May 20-40. % / 10-30 May. %, preferably 45-55 May. % / May 25-35. % / May 15-25. %.

Possible implementation of the invention, in which the distribution of the third stream between the three reaction zones is 20-40 May. % / May 25-45. % / May 25-45. %, preferably 25-35 May. % / May 30-40. % / May 30-40. %. Possible implementation of the invention, in which the distribution of the catalyst for the reaction is 10-30 May. % / May 20-40. % / 40-60 May. % of the total amount of catalyst for the first / second / third reaction zone, respectively, preferably 15-25 May. % / May 25-35. % / 45-55 May. % of the total amount of catalyst.

Possible execution of the invention, in which the hydrocarbon fraction is 62-88 May. % of the supplied raw materials, preferably 75-80 May. % of the supplied raw materials.

Possible execution of the invention, in which the olefin-containing fraction is 7-33 May. % of the supplied raw materials.

It is possible to carry out the invention, which makes it possible to achieve an octane number by the research method of a liquid hydrocarbon product of more than 90 units, with a benzene content in the liquid hydrocarbon product not exceeding 1.2 May. %.

An embodiment of the invention is possible, in which the zeolite catalyst comprises: a. zeolite of the ZSM-5 type with the S1O2 / AI2O3 module from 43 to 95 in an amount from 65 to 80 May. %,

B. sodium oxide in an amount from 0.04 to 0.15 May. %, c. zinc oxide in the amount of 1.0-5.5 May. %, d. oxides of rare earth elements in a total amount of 0.5-5.0 May. %, 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.

It is possible to carry out the invention in which the rare earth elements are selected from the group including lanthanum, praseodymium, neodymium, cerium, as well as 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:

R101 - the first reaction zone;

R201 - second reaction zone;

R301 - 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, for carrying out experiments on examples 1-6, the entire hydrocarbon fraction was distributed to the first reaction zone (i.e., the second and third streams of hydrocarbon fraction were not created). To carry out the experiment according to example 7, the hydrocarbon fraction was distributed into three reaction zones (i.e., created the first, second and third streams of the hydrocarbon fraction). Also, if necessary, it is possible 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 into the first, second and third reaction zones. For this, the oxygenate is divided into first, second and third oxygenate streams fed to the first, second and third reaction zones, respectively.

The olefin-containing fraction is fed into the first, second and third reaction zones. For this, the olefin-containing fraction is separated into first, second and third streams of the olefin-containing fraction fed to the first, second and third reaction zones, respectively.

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 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 fraction of the gaseous product, enriched hydrocarbons C ₃ -C ₄ , and a fraction of the gaseous product enriched in hydrocarbons C1-C2.

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 can contain not only С ₅₊ hydrocarbons, but also different amounts of dissolved gases С ₁ -С ₄ . In particular, in the production of motor gasolines, it is usually allowed to be present until May 3-5. % of dissolved gases in summer gasolines and up to May 5-7. % of dissolved gases in winter gasolines. The gaseous product can 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 results achieved are illustrated below in Examples 1-5, 7 and Comparative Example 6.

Comparative example 6 differs from the proposed method in that it does not meet the criterion "the temperature at the inlet of each subsequent reaction zone must be higher than the temperature at the inlet of each previous zone."

For the experiments, a catalytic installation was used, including three reactors connected in series, with a total catalyst loading of up to 9 liters. The reactors are designated as first, second and third reaction zones, R101, R201 and R301, 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 the temperature difference between the thermocouples at the outer wall of the reactor and the thermocouple opposite at the inner surface of the reactor basket.

Liquid and gaseous 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 1-7. 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.

Table 2 shows the compositions of the olefin-containing fractions used in Examples 1-7. The used olefin-containing fractions can be considered, for example, as a model of a dry gas of catalytic cracking (the compositions of the SGCC were obtained by averaging the data of the refinery over several months of operation of the catalytic cracking unit). 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 May. %. The olefin-containing fraction may contain hydrogen in a concentration of 0.5 to 8 May. %, preferably from 2.3 to 8 May. % hydrogen, more preferably 3 to 8 May. % hydrogen. 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%.

Methanol technical grade "A" GOST 2222-95 was used as oxygenate in examples 1-3 and 6-7. Example 4 used dimethyl ether (DME), 99%. Example 5 uses 95% ethanol.

Table 3 shows the compositions of the zeolite catalysts used in examples 1-7. Table 4 shows the conditions and basic parameters of examples 1-6. The hydrocarbon fraction in examples 1-6 is fed to the first reaction zone. Example 7 repeats the conditions of Example 1, except that in Example 7 the hydrocarbon fraction is distributed over the three reaction zones in a ratio of 50/30/20 May. %. 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% oxygenate substitution (percentage of oxygenate substitution for olefin-containing fractions) is calculated using formulas (4) - (6) on pages 3-4 of this Description.

Tables 5 and 6 show the compositions of the resulting liquid hydrocarbon product of Examples 1-6. Example 7 shows the yield of liquid hydrocarbon product C5 ₊ 75.4 wt. % on the supplied hydrocarbon fraction at a product RON of 90.0 units. and an aromatic content of 30.0 May. % (data are given for a liquid hydrocarbon product that does not contain dissolved gases, similar to Table 5).

Table 6 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 May. % (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 foods in Table 6 contain from May 3 to May 5. % dissolved gases C1-C4. However, depending on the goals of a particular production, the liquid hydrocarbon product may contain different amounts of dissolved gases C1-C4. In particular, in the production of motor gasolines, it is usually allowed to be present until May 3-5. % of dissolved gases in summer gasolines and up to May 5-7. % of dissolved gases in winter gasolines. 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 6, however, Table 5 shows the composition of the liquid hydrocarbon products without dissolved gases C1-C4 (fraction C5 ₊ 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 C5 ₊ 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, a comparison of the parameters of a product that does not contain more than preferably. However, we note that, depending on the goals of a particular production, the liquid hydrocarbon product may contain not only C5 ₊ hydrocarbons, but also different amounts of dissolved gases C1-C4, as shown in Table 6, for example.

Since C5 ₊ 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 C5 _{+ hydrocarbons.}

The gaseous product in examples 1-7 consisted mainly of saturated hydrocarbons and nitrogen. The source of nitrogen is the olefin-containing fractions fed to the reaction. In examples 1-5 and 7, the content in the gaseous product of hydrocarbons Cs ₊ (mainly propane) was 32-68 vol. %. The total content of olefins in the gaseous product was 0.7-1.3 vol. %, which shows a high degree of conversion of feed olefins. The ethane content was 0.2-0.8 vol. %, which indicates the suppression of side processes of ethylene hydrogenation by hydrogen of the feedstock.

Table 1. Composition of hydrocarbon fractions, May. %

P (normal paraffins), I (isoparaffins), O (olefins), N (naphthenes), A (aromatics) ’The indicator serves to assess the composition of the fraction. Due to rounding to one and the presence of unrecognized components, it may not add up to 100.0%.

Straight-run gasoline, as - the end of boiling is not determined. Table 2. Composition of olefin-containing fractions, May. %

Table 3. The composition of the zeolite catalysts used in examples 1-6.

* 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, intermediate products of the production of rare earth elements with a content of mixed compounds of rare earth elements of at least 60 May can be used. %, such as a concentrate of rare earth elements, rough rare earth concentrate of rare earth elements, collective concentrates of rare earth metals, intermediate products 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 1-6 ^***

Rioi _, R201, R301 - the first, second and third reaction zones.

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

^** In experiments 1-6, the entire hydrocarbon fraction is distributed to the first reaction zone. Table 5. Composition of a liquid hydrocarbon product that does not contain dissolved gases

P (normal paraffins), I (isoparaffins), O (olefins), N (naphthenes), A (aromatics) 'The indicator serves to assess the composition of the fraction. Due to rounding to one and the presence of unrecognized components, it may not add up to 100.0%. Table 6. Composition of the stabilized liquid hydrocarbon product.

The output of the stabilized liquid hydrocarbon product (stable gasoline after separation of the gaseous product) to the supplied hydrocarbon fraction.

Observations

It was found that the maximum yield of liquid hydrocarbon product and / or an increase in the selectivity of the formation of hydrocarbons C5 _{+ is} achieved while maintaining essentially the same heating temperatures in each reaction zone. Due to the application of the proposed method, the temperature heating in each of the reaction zones differs from the heating temperature in the other reaction zones by no more than 10 ° C, preferably no more than 5 ° C. The temperature heating of the reaction zone is understood as the difference between the maximum temperature of the catalyst layer of the reaction zone and the temperature of the feedstock supply to this reaction zone, ° C.

Note that hereinafter, the temperature at the inlet of the reaction zone means the temperature of the feed to this reaction zone. However, in special cases, depending on the operating conditions of industrial equipment, the temperature of the feed to the reaction zone and the temperature at the inlet to the reaction zone may differ. For example, a feed heated to a feed temperature for a particular reaction zone can be cooled in a pipeline leading from a feed heater to the inlet of that reaction zone. To successfully achieve technical results, attention must be paid to the temperature at the inlet of the reaction zone, and the temperature at the inlet of each subsequent reaction zone must be higher than the temperature at the inlet of each previous zone.

To measure the temperature at the inlet of the reaction zone, for example, a thermocouple can be positioned at the beginning of the catalyst bed. Note that for the purposes of comparison with known methods, when placing a thermocouple at the beginning of the catalyst layer, it is important not to install it in the region where a sharp increase in temperature is observed in the frontal layer in the known methods. In the known methods of methanol processing, in contrast to the proposed method, there is a sharp heating of the catalyst in the frontal catalyst layer (a sharp increase in temperature in about the first quarter of the catalyst layer in the direction of feedstock supply). The proposed method makes it possible to significantly smooth the heating peak by reducing the rate of temperature rise in the catalyst bed in the direction of feedstock supply.

The achieved heating values are illustrated by examples 1-5 according to the invention (see Table 4). At the same time, in comparative example 6, it was not possible to achieve essentially the same heating temperatures in each reaction zone.

Found that the proposed method allows you to achieve this result without the use of reactors with built-in heat exchangers (for example, 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 at 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 difference in temperature heating between the reaction zones without the use of built-in heat exchangers.

In the known methods, an increase in yield is often achieved at the expense of a deterioration in the quality of the liquid product produced. However, examples 1-5, Tables 4-5, show that in the proposed method, with an increase in the yield of a liquid product and / or an increase in the selectivity of the formation of the C 5 ₊ hydrocarbon fraction, it is possible to provide the RON of the liquid hydrocarbon product at a level above 90 units. and it is possible to ensure the benzene content in the liquid hydrocarbon product is not higher than 1.2 May. % (about 1 vol.%). At the same time, the selectivity of the formation of Cs ₊ hydrocarbons increases in comparison with the comparative example, reaching 36-49 May. %; the yield of the liquid product increases by May 3-7. %.

All examples, according to the proposed method, show the conversion of olefins C2-C4 feed above 98 May. %. This makes it possible not to use the recycle of gaseous products for the purposes of a more complete processing of the olefins of the feedstock.

Examples 1-5 also show the possibility of using little-demanded olefin-containing fractions as feedstock for the production of gasolines. In this case, olefin-containing fractions act as a partial replacement for oxygenates.

Co-processing of hydrocarbon fractions and oxygenates (without involving olefin-containing fractions) often makes it possible to obtain gasolines with high RON and product yields per supplied hydrocarbon fraction. However, oxygenates such as methanol, ethanol, dimethyl ether are rarely available in refineries. When the source of oxygenate cannot be found in the by-product or intermediate product of the enterprise, it has to be purchased from outside at the prices of the commercial product. This increases the cost of producing a unit of gasoline, and complicates the logistics of producing commercial gasoline.

The possibility of partial replacement of oxygenates with olefin-containing gases is important for the following reasons. Co-processing of hydrocarbon fractions and oxygenates often makes it possible to obtain gasolines with high RON and product yields per supplied hydrocarbon fraction. However, oxygenates such as methanol, ethanol, dimethyl ether are rarely available in refineries. When a source of oxygenate cannot be found in a by-product or intermediate enterprises, it has to be purchased from outside at the prices of a marketable product. This increases the cost of producing a unit of gasoline, and complicates the logistics of producing commercial gasoline.

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 dilute olefins instead of highly concentrated sources of olefins (eg, pure ethylene). This creates an opportunity as a source of olefins, intermediates and by-products of already existing petrochemical plants. Among them are dry gases of catalytic cracking, various fuel gases with olefin content from 10 to 50 May. %. The calculation of the percentage of substitution of oxygenates for olefin-containing fractions is carried out according to formulas (4) - (6) on pages 2-3 of this Description. In particular, examples 1-5 show the possibility of replacing from 39 to 84% of the oxygenate with olefin-containing fractions while maintaining the yield of the C 5 ₊ hydrocarbon product fraction of more than 70% for the supplied hydrocarbon fraction, and the RON of the liquid hydrocarbon product above 90 units.

The calculations provided can be applied to the already known methods of co-processing hydrocarbon fractions and oxygenates 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.

Distributed supply of hydrocarbon fraction

It was noticed that changing the supply 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 C1-C4 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 7 shows the possibility of distributing the hydrocarbon fraction over several reaction zones. Example 7 repeats the conditions of Example 1, except for a change in the distribution of the hydrocarbon fraction. Example 1 the distribution of the hydrocarbon fraction over the Rioi / R201 / R301 reaction zones was 100/0/0 May. %. Example 7 retains the same mass flow rates of raw materials as Example 1, however, the hydrocarbon fraction is distributed over the three reaction zones in a ratio of 40/40/20 May. %. As a result, it is possible to increase the product yield on May 3. % for the supplied hydrocarbon fraction (from 72.2 to 75.4 wt% for a liquid hydrocarbon product that does not contain dissolved gases). In this case, the selectivity of the formation of C5 ₊ hydrocarbons increases from 47.1 for example 1 to 48.2 for example 7.

The aromatics content in the product of Example 7 (liquid hydrocarbon product, free of dissolved gases C1-C4) is reduced by 2.8 May. % compared to example 1 (from 32.8 to 30.0 May.%). 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 7 is practically indistinguishable from the RHI of the product of Example 1 (90.2 units and 90.0 units, respectively). This effect can be explained by a decrease in the cracking of high-octane Cs-Cs 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.

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

Claims

FORMULA

1. A method of increasing the yield of a liquid hydrocarbon product and / or the selectivity of the formation of Cs ₊ hydrocarbons in a method for producing gasolines, in which three streams are used as feedstock, the first of which includes a hydrocarbon fraction, the second stream includes an oxygenate, the third stream includes an olefin-containing fraction, where: 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 May. %,

B. use three reaction zones filled with zeolite catalyst, c. the first stream is fed to at least one reaction zone, d. the second stream is partitioned into three reaction zones e. the third stream is distributed into three reaction zones, f. 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, g. moreover, the temperature at the inlet of each subsequent reaction zone is higher than the temperature at the inlet of each previous zone.

2. A process according to claim 1, wherein the first stream is preferably fed to the first reaction zone.

3. The method according to claim 1, wherein the hydrocarbon fraction contains normal paraffins in an amount of 15-24 May. %, isoparaffins in the amount of 42-56 May. %, naphthenes in the amount of May 22-40. %, the rest is aromatic hydrocarbons and olefins.

4. The method according to claim 1, wherein the hydrocarbon fraction contains from 0 to 80 May. % hydrocarbons C _b , preferably from 23 to 46 May. % C _b hydrocarbons, most preferably from 36 to 46 May. % hydrocarbons C _b.

5. The method according to claim 1, wherein the hydrocarbon fraction contains from 0 to 70 May. % C7 isoparaffins, preferably from 26 to 50 May. % C7 isoparaffins, most preferably from 26 to 38 May. % C7 isoparaffins.

6. The method according to claim 1, in which the hydrocarbon fraction can be selected from the group consisting of straight-run gasoline, stable gas gasoline, light gas condensate, gasoline fraction with boiling points of about 62 ° - 85 ° C, raffinate, and mixtures thereof.

7. The method according to claim 1, in which the oxygenate is selected from the group consisting of aliphatic alcohols and ethers, for example, methanol, ethanol, crude methanol, technical methanol, dimethyl ether, as well as mixtures thereof, including with water.

8. A process according to claim 1, wherein the oxygenate may contain impurities, for example, aldehydes, carboxylic acids, esters, unsaturated alcohols.

9. The method of claim 1, wherein the olefin-containing fraction, the olefin-containing fraction, comprises 2.3-8.0 wt. % hydrogen, preferably 3.2-8.0 wt. % hydrogen.

10. The method according to claim 1, wherein the mass fraction of C5 ₊ hydrocarbons in the olefin-containing fraction is from 0 to 10.0 wt%. %, preferably from 0 to 5.0 May. %.

11. The method according to claim 1, in which the volume fraction of hydrogen sulfide in the olefin-containing fraction is not more than 0.005%.

12. The process according to claim 1, wherein the first olefin-containing fraction may include non-olefin hydrocarbon components, for example, methane, ethane, propane, butane, may contain inorganic gases, for example, hydrogen, nitrogen, may contain heavier impurities olefins C5 ₊ , for example, pentenes, hexenes.

13. The process according to claim 1, wherein the olefin-containing fraction is selected from the group consisting of dry catalytic cracking gas, catalytic cracking wet gas, coker off-gas, Fischer-Tropsch synthesis gases, thermal cracking gas, visbreaking gas, off-gases hydrocracking, pyrolysis gas, gaseous waste from the catalytic reforming unit, waste fuel gases of various origins, as well as their mixtures.

14. The process according to claim 1, wherein the olefin-containing fraction comprises dry catalytic cracking gas and contains from 25 to 40 May. % of C2-C4 olefins.

15. The method according to claim 1, wherein the mass feed rate of the raw material is from 0.5 to 10 h ¹ , preferably 1-3 h ¹ .

16. 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.

17. The method according to claim 1, in which the temperature of the stream at the entrance to the first / second / third reaction zone is 330-350 ° C / 340-360 ° C / 350-370 ° C, preferably 335-345 ° C / 345- 355 ° C / 355-365 ° C.

18. The method of claim 1, wherein the distribution of the second stream between the three reaction zones is 40-60 May. % / May 20-40. % / 10-30 May. %, preferably 45-55 May. % / May 25-35. % / May 15-25. %.

19. The method according to claim 1, wherein the distribution of the third stream between the three reaction zones is 20-40 May. % / May 25-45. % / May 25-45. %, preferably 25-35 May. % / May 30-40. % / May 30-40. %.

20. The method according to claim 1, in which the distribution of the catalyst over the reaction is 10-30 May. % / May 20-40. % / 40-60 May. % of the total amount of catalyst for the first / second / third reaction zone, respectively, preferably 15-25 May. % / May 25-35. % / 45-55 May. % of the total amount of catalyst.

21. The method of claim 1, wherein the hydrocarbon fraction is 62-88 wt. % of the supplied raw materials, preferably 75-80 May. % of the supplied raw materials.

22. The method of claim 1, wherein the olefin-containing fraction is 7-33 wt. % of the supplied raw materials.

23. The method according to claim 1, which makes it possible to achieve an octane number according to the research method of a liquid hydrocarbon product of more than 90 units, with a benzene content in the liquid hydrocarbon product not exceeding 1.2 May. %.

24. The method of claim 1, wherein the zeolite catalyst comprises: a. zeolite of the ZSM-5 type with a SiCh / AhCb modulus from 43 to 95 in an amount from 65 to 80 May. %,

25. The method of claim 24, wherein the zeolite catalyst is free of platinum metals.

26. The method of claim 24, wherein the rare earths are selected from the group consisting of lanthanum, praseodymium, neodymium, cerium, and mixtures thereof.

27. The method of claim 1, wherein the reaction is carried out in the gas phase in a fixed bed of catalyst.