RU2325426C2 - Method of hydrocarbon raw materials processing - Google Patents

Abstract

FIELD: inorganic chemistry.

SUBSTANCE: invention refers to processing of hydrocarbon raw materials including black oil containing fractions with boiling temperature 350°C, including high-temperature heat-transfer agent generation by means of oxidized fuel combustion, preheating of hydrocarbon raw materials higher than melting point, but lower than temperature of coke or resin formation, and simultaneous supply of high-temperature heat-transfer agent and preheated hydrocarbon raw material to reaction zone within pyrolysis chamber, hydrocarbon raw material heating at rate equal to (4-5)-10⁵ degrees/sec up to temperature 700-2500°C, followed by quenching of reaction products characterized by the fact that high-temperature heat-transfer agent contains hydrogen within concentration range 30-35% by volume. After temperature point 700-2500°C is reached in reaction zone reaction flow is two-staged added with quenching components and reaction mixture is cooled at cooling rate 1.10 -5.10 degrees/sec up to 600-1300°C on the first stage and at cooling rate 2.10⁴-4.10⁴ degrees/sec up to temperature 300-1000°C on the second stage to provide termination of secondary processes. Method enables to reduce sulphur content in end products, increase product yield and reach breakup control of end products.

EFFECT: reduced sulphur content in end products; reached breakup control of end products and improved process efficiency.

2 cl, 1dwg, 4 tbl, 4 ex

Description

The invention relates to thermal non-catalytic pyrolysis of hydrocarbon, in particular petroleum feedstocks, and is intended for the destructive high-temperature conversion of heavy hydrocarbons (crude oil, fuel oil, heavy oil residues, tar, etc.) and can be used in the oil refining industry.

One of the main trends in the development of the modern oil refining and petrochemical industry is the deepening of oil refining, which is achieved mainly due to the transition to the use of heavy types of raw materials and the intensification of processes.

The application of high-temperature destructive pyrolysis technology is aimed at achieving the maximum yield of target products, such as synthesis gas, olefins, light oil products, etc., by carrying out the process under the most severe conditions (temperature and time of the process) compared to various types of thermal processing of crude oil, as well as the process of removing sulfur from raw materials and target products through the interaction of hydrogen with sulfur-containing compounds in harsh conditions.

A known method of processing hydrocarbon materials, in particular gas oil, fuel oil and other fractions of heavy hydrocarbon materials by thermal pyrolysis according to US Pat. RF №2145626, С10G 9/36, 9/38, 02.20.2000. The essence of this method lies in the fact that in the process of processing hydrocarbon feedstock into the cylinder volume of the internal combustion engine when the piston moves to the bottom dead center at the intake stroke, the prepared air-fuel mixture is supplied in an amount of 40-50 vol.% Of the volume of reactants of one cycle with the ratio of the amount of oxygen to the amount of hydrocarbon feedstock α = 1.0-1.1 and squeeze it with a piston until self-ignition occurs and burn, after which, when the piston moves to bottom dead center, the processed feed is fed into the cylinder in lichestve 60-50 vol.% of one cycle of the reagents and mixed with the flue gases combusted fuel mixture and subsequent pyrolysis quenching the pyrolysis products is carried out during the same stroke of the piston to the bottom dead point. The conclusion of the reaction products from the reaction volume is produced when the piston moves to top dead center. Next, a new portion of the mixture of hydrocarbons with air is introduced as the piston moves to bottom dead center.

The process is repeated at a frequency of 500-1500 cycles per minute. The values of the coefficient α = 1.0-1.1 are due to the requirement of the maximum complete combustion of the entire air-fuel mixture and heating of the smoke to high temperatures (2000-2300 ° C).

Fuel oil is used as a pyrolyzable feedstock, with a sulfur content of 2.0-4.0%, a density of 970 kg / m ³ and a boiling point of 330 ° C. Pyrolysis of the indicated oil leads to the following composition (%) at the output of oil products: ethylene - 34; propylene - 13; butadiene - 4; pyrocondensate - 8; heavy resin - 22.

The main disadvantage of the method of processing hydrocarbon raw materials according to the patent of the Russian Federation No. 2145626 is the lack of continuity of the process of pyrolysis of hydrocarbons due to its cyclical nature, which reduces the productivity of the process. Another disadvantage of this method of processing hydrocarbon raw materials is the lack of a sulfur removal process (hydrodesulfurization).

There is also a known method of producing olefins by high temperature pyrolysis of hydrocarbons according to US patent No. 4256565, class. C10G 9/36, 03/17/1981. According to this analogue, olefins in high yield are obtained from hydrocarbon feedstocks, especially from heavy oil fractions. In this case, a stream of gaseous oxygen is introduced into the first reaction zone and hydrogen gas is simultaneously supplied thereto along the periphery of the oxygen stream at a temperature of 500-800 ° C, which leads to a spontaneous combustion reaction. Hydrogen and oxygen are introduced in such quantities to obtain a gas stream of reaction products in the temperature range from 1000 to 2000 ° C, with an excess of hydrogen compared with the amount of water vapor. The gas stream thus obtained is fed into the second reaction zone, in which it contacts the hydrocarbon stream introduced therein, heated to a temperature above their melting point, but below the temperature at which coke or resin is formed from them. The first and second reaction zones are directly adjacent to each other.

The angle of the colliding gas stream from the first reaction zone and the supplied hydrocarbon stream in the second reaction zone is 25 ° -45 °. The gas stream is introduced into the second reaction zone at a high speed and in sufficient quantity to create a reaction mixture having a temperature in the range of 800-1800 ° C, while the heating rate of the processed hydrocarbons in the second reaction zone is 2 · 10 ⁵ deg / s. For the formation of olefins, the resulting reaction mixture stream is maintained at this temperature for (1-10) · 10 ^-3 s. Then the reaction stream is subjected to rapid quenching to a temperature of less than 600 ° C for a time of less than 2 · 10 ^-3 s in a Laval nozzle with simultaneous injection of water and sent to the selection of olefin products.

The main disadvantages of the known method of processing hydrocarbon feedstocks according to US patent No. 4256565 is a limited set of components (hydrogen and oxygen) for generating a coolant, its low temperature (1000-2000 ° C), insufficient flexibility of regulation of the pyrolysis process, which does not allow to obtain a wide range of target products and does not lead to a more complete and useful use of hydrocarbons of processed mixtures. Another disadvantage of this method of processing hydrocarbon raw materials is the lack of a sulfur removal process (hydrodesulfurization).

A known method of processing hydrocarbon raw materials (RF patent No. 2188846), adopted as a prototype. According to the prototype, hydrocarbons are processed into target products, such as synthesis gas, olefins, light oil products (motor fuel hydrocarbons), coke, soot, etc.

The problem in the prototype is solved due to the fact that in the method of processing hydrocarbon raw materials, including in the form of heavy oil residues containing fractions boiling at temperatures above 350 ° C, including the generation of a high-temperature coolant by burning fuel in oxygen, preheating the hydrocarbon feed higher than the melting point, but lower than the temperature of the coke or gum formation, and the simultaneous supply of high-temperature coolant and pre-heated hydrocarbon feedstock to the reaction zone pyrolysis chamber with subsequent quenching of the reaction products, the distinguishing feature of which is that the hydrocarbon feed is heated to temperatures of 700-2500 ° C in the reaction zone at a rate of (4-5) · 10 ⁵ deg / s.

The main disadvantage of this method is the absence of hydrogen in a high-temperature coolant and, therefore, the absence of a process for removing sulfur from raw materials and target products of processing raw materials.

The objective of the proposed method for processing hydrocarbon raw materials is to expand the types of processed raw materials, increase the depth of their processing, conduct a process of non-catalytic hydrodesulfurization of raw materials and, accordingly, reduce the sulfur content in the target products, increase the yield and control the fractional composition of the target products, such as synthesis gas, olefins, light oil products (hydrocarbon motor fuels), coke, soot, etc.

The problem in the claimed invention is solved due to the fact that in the method of processing hydrocarbon raw materials, including in the form of heavy oil residues containing fractions boiling at a temperature above 350 ° C, including the generation of a high-temperature coolant by burning fuel in oxygen, pre-heating the hydrocarbon raw materials above the melting point, but lower than the temperature of coke or gum formation, and the simultaneous supply of high-temperature coolant and pre-heated hydrocarbon feed the reaction zone of the pyrolysis chamber with subsequent quenching of the reaction products, when the hydrocarbon feed is heated to temperatures of 700-2500 ° C in the reaction zone at a rate equal to (4-5) · 10 ⁵ deg / s, a distinctive feature of which is that the high-temperature coolant contains hydrogen in the concentration range from 4 to 50% by volume, and the reaction products are quenched in two stages with different cooling rates by the introduction of quenching components.

To generate a high-temperature coolant, the recycled part of the processed raw material is used as fuel.

After reaching a temperature of 700-2500 ° C in the reaction zone, quenching components are introduced into the reaction stream in two stages and the reaction mixture is cooled with a cooling rate of 10 ⁵ -10 ⁶ deg / s to a temperature level of 600-1300 ° C in the first stage and with a cooling rate 10 ⁴ -10 ⁵ deg / s to a temperature level of 300-1000 ° C in the second stage to stop the secondary processes.

In parallel with the process of pyrolysis of hydrocarbon feedstock, a process of non-catalytic hydrodesulfurization of feedstock with hydrogen contained in a high-temperature coolant is carried out.

Thanks to the inventive method for processing hydrocarbon raw materials, a technical result was obtained, namely, the range of processed raw materials was expanded, the depth of its processing was increased, the process of non-catalytic hydrodesulfurization of raw materials was carried out, and, accordingly, the sulfur content in the target products was reduced, the yield was increased and the fractional composition of the obtained target products was achieved, such as olefins, light petroleum products (hydrocarbon motor fuels), etc.

The drawing shows a diagram of the technological process of processing hydrocarbon raw materials.

According to the claimed method, the processed hydrocarbon feed is fed to a multi-purpose high-temperature reactor (BTP) 1, consisting of a gas generator (GT) 2 and a pyrolysis chamber (PC) 3. Fuel from the fuel supply unit 4 and the oxidizing agent from the oxidizer supply unit 5 are supplied to the GT 2 for generation high-temperature coolant containing from 4 to 50 vol.% hydrogen, in the temperature range 2700-2900 ° C, which through the critical nozzle 6 is fed into the pyrolysis chamber (PC) 3. Pyrolysis chamber 3 consists of two reaction zones: the first reaction zone (ZR -1) 7 and sec th reaction zone (RR-2) 8, which are adjacent to each other and separated by zones 9, 10 for introduction of quench injection, through the belt 9 and additional injection through the injection zone 10 components. In ZR-1 7, preheated processed hydrocarbon feedstock is introduced into the high-temperature coolant stream through the injection unit 11, and the necessary additional components are introduced through the injection unit 12, where they are effectively mixed with the high-temperature coolant. The resulting mixture is brought to a temperature in the range of 700-2500 ° C with a temperature increase rate of (4-5) · 10 ⁵ deg / s and from it form the reaction stream of the primary pyrolysis in ZR-1 7. In this case, the pyrolysis process is carried out and hydrodesulfurization of raw materials. The products of primary pyrolysis and hydrodesulfurization are quenched by injection through an injection unit 9 with a quenching component, cooling them to a temperature of 600-1300 ° C with a cooling rate of 10 ⁵ -10 ⁶ deg / s, and fed to ЗР-2 8, forming a reaction stream of secondary pyrolysis. The products of hydrodesulfurization and secondary pyrolysis at the outlet of ZR-2 8 are quenched to prevent secondary reactions by injecting quenching components through the injection unit 13, cooling them to a temperature of 300-1000 ° С with a cooling rate of 10 ⁴ -10 ⁵ deg / s, and then for separation into target products in block 14 separation. Changing the secondary pyrolysis process and regulating the composition of the target products is carried out by introducing additional components through the injection unit 10. The initial processed raw materials, additional and hardening components are prepared in the preparation unit 15 (BP) and fed into the pyrolysis chamber 3, through injection belts 11, 10 and 12, 9 and 13, respectively, which are a series of nozzles (not shown) located along the perimeter of PC 3. In BP 15, the initial hydrocarbon feedstock is preheated above the melting point, but below the coke or gum formation temperature, and they also provide a metered supply of raw materials, additional and quenching components, through the respective belts injection.

The following is an example implementation of the inventive method of processing hydrocarbon feedstocks. The inventive method is implemented on a pilot installation of continuous operation based on a high temperature reactor using hydrocarbon feedstocks. Table 1 shows some physico-chemical characteristics, and table 2 shows the hydrocarbon group composition of the feedstock.

Table 1 Physico-chemical characteristics of the feedstock Characteristic Value Density, g / cm ³ (GOST 3900-47) 0.952 Pour point, ° C (GOST 30287-74) +15 Water content, wt.% (GOST 1461-75) 0.00108-0.0116 The content of solids,% 0.0020-0.0032 Elemental composition, wt.%: Carbon 82.5-85.6 Hydrogen 13.0 Oxygen 0.7 Nitrogen 0.1 Sulfur 0.5-3.5 Other items 0.1 Fractional composition, ° C N.K. 172 10% boils off at 343 fifty% 416 90% 476 K.K. 520 Kinematic viscosity at + 50 ° С, cSt (GOST 33-66) 17.42

table 2 Hydrocarbon group composition of hydrocarbons, wt.% No. p / p Components Amount, wt.% one Asphaltenes 0.8 2 Alcohol-benzene resins 3.6 3 Benzene resins 6.6 four Oils including:
methane-naphthenic
Benzene
Mothballs
Anthracene
petroleum ether resins 89.0 4.1 64.35 4.2 12.73 4.3 4,54 4.4 6.41 4.5 0.97

The main physical and mass characteristics of the optimized process for the pyrolysis of hydrocarbons with a sulfur content of 3.5% for the production of fuel hydrocarbons are shown in table 3.

Table 3 Process parameters Component, VTR block Relative component consumption The temperature at the entrance to the VTR, ° C The reaction temperature, ° C Reaction time, s Amount of fuel (natural gas) + oxygen, gas generator 2 200 2400 0.01 Steam, ZR-1 2 200 Raw materials, ЗР-1 0.3 180 1400-1200 0,020 Water, ЗР-2 0 Raw materials, ЗР-2 one 180 900-600 0,080 Quenching component (water) 2 25 600-200

Example 1. In a gas generator 2, fuel is burned in an oxidizing agent with an oxidizer excess ratio of 0.95-0.7 and the formation of gaseous products with a temperature of 2000-2500 ° C with a hydrogen content of 4-15% by volume. The fuel used is natural or associated gas, process recycle gases, recyclable materials, recyclable part of the recyclable material. The processing in the pyrolysis chamber 3 is carried out at pressures up to 5.0 MPa in order to increase the yield of liquid hydrocarbons. The resulting gases are fed through a critical nozzle 6 to ZR-1 7, where they are mixed with steam supplied to the same zone through the injection belt 12, and the resulting hot gas stream is quenched by the processed raw materials supplied through the injection belt 11, while steam-carbon dioxide conversion is carried out raw materials with the formation of hydrogen and carbon monoxide, bring the hydrogen content to 30-35% by volume and cool to a temperature equal to 1150-1300 ° C. The resulting vapor-gas stream is directed to ZR-2 8 where it is quenched at a rate of 1 · 10 ⁵ -5 · 10 ⁵ deg / s by mixing with the processed raw materials supplied through the injection belt 10. In ЗР-2 8 in the initial part of ЗР-2 8, the temperature is maintained equal to 1000-800 ° С, and in the final part of ЗР-2 8 - 700-600 ° С. The resulting pyrolysis products are quenched with water supplied through the injection belt 13 at a rate of 2 · 10 ⁴ -4 · 10 ⁴ deg / s and sent to the separation unit 14 for the separation of fuel hydrocarbons. The feedstock, additional and hardening components are prepared in block 15 preparation.

Example 2. It differs from example 1 in the rate of quenching with raw materials in ZR-2 8, reduced to values of 1 · 10 ⁴ -3 · 10 ⁴ deg / s and quenched with water supplied through the injection belt 13 at a speed reduced to 1 · 10 ³ - 2 · 10 ³ deg / s.

Example 3. It differs from example 1 in a reduced hydrogen content to 20-25% after steam-carbon dioxide conversion of the feed.

Example 4. It differs from example 1 in an increased hydrogen content up to 40-50% after steam-carbon dioxide conversion of the feed.

The content of fuel hydrocarbons of light and light gas oil fractions and other related products of the pyrolysis of raw materials obtained by this processing method are shown in table 4. In the same table, for comparison, the yields of the products according to patent RU 2188846 are given.

Table 4 The content of components in the products of the conversion of raw materials (wt.%). Components The content of components in the conversion products of raw materials, wt.% According to the patent of the Russian Federation No. 2188846 (table 10) The content of components in the products of the conversion of raw materials, wt.% According to the claimed method Examples one 2 3 four Saturated gases C ₁ -C ₄ 15,5 15,5 22.6 12,2 27 Acetylene 1.7 1,6 1,2 1.9 0.6 Ethylene 18.5 11.5 8 10.8 6 Unsaturated C ₃ -C ₄ 3.5 3,1 1,5 2.2 1.8 Light oil products, (T _to <350 ° C) and light gas oil (350 ° C <T _to <530 ° C) 59.19 63.9 44.1 56 48 Coke 0 0 8 0.6 0 Tar residues _(Tc> 530 ° C) 0.9 0.9 eleven 13 0.8 Sulfur content in processed products: Gaseous products (Hydrogen sulfide and mercaptans in terms of sulfur) There is no data 1,5 1,1 0.3 2,3 Light oil products There is no data 0.1 0.6 0.8 0.1 Coke and heavy petroleum products There is no data 1.9 1.8 2,4 1,1

A comparison of the data of the patent RU 2188846 and example 1 in table 4 shows that when the hydrogen content in the products of steam-carbon dioxide conversion of raw materials is 30-35% and the hardening rates are 1 · 10 ⁵ -5 · 10 ⁵ deg / s in the unit ЗР-2 and 2 · 10 ⁴ -4 · 10 ⁴ deg / s in the injection belt 13 increases the yield of light oil products and light gas oil by the present method and at the same time decreases the yield of gaseous unsaturated hydrocarbons. In addition, we can note the redistribution of sulfur of the feedstock (3.5% of the total feed) in gaseous products (1.5% of the feed) with a decrease in the sulfur content in light petroleum products (0.1% of the feed).

The data of example 2 allow us to conclude that a decrease in hardening rates in the ZR-2 blocks to 1 · 10 ⁴ -3 · 10 ⁴ deg / s and in the injection belt 13 to 1 · 10 ³ -2 · 10 ³ deg / s leads to a decrease yield of light and gas oil fractions and increase the yield of gaseous saturated hydrocarbons. At the same time, a significant part of sulfur remains in the composition of liquid hydrocarbons and the yield of coke and tar increases significantly.

The data of example 3 demonstrate that a decrease in the hydrogen content in the products of steam-carbon dioxide conversion of raw materials to values of 20-25% leads to an increase in the yield of explosive acetylene, a decrease in the yield of light oil products and light gas oil, and an increase in the sulfur content in light fractions.

The data of example 4 show that an increase in the hydrogen content in the products of steam-carbon dioxide conversion of raw materials to 40-50% leads to an increase in the yield of saturated gaseous hydrocarbons with a decrease in the yield of light oil products and light gas oil and unsaturated hydrocarbons. The sulfur content in liquid hydrocarbons is almost unchanged.

Thus, the optimal mode for producing liquid hydrocarbons with a low sulfur content and unsaturated hydrocarbons is the mode of example 1.

Based on the results of the implementation of the method, we can conclude that, thanks to the claimed method of processing hydrocarbon raw materials, a technical result was obtained, namely, a decrease in the sulfur content in light oil products was achieved compared to the feedstock, the depth of processing of raw materials was increased, and the range of target products obtained was expanded .

Claims (2)

1. A method of processing hydrocarbon raw materials, including in the form of heavy oil residues containing fractions boiling at temperatures above 350 ° C, including the generation of a high-temperature coolant by burning fuel in oxygen, preheating the hydrocarbon raw material above the melting point, but below the coke temperature or resin formation, and the simultaneous supply of a high-temperature coolant and pre-heated hydrocarbon feedstock to the reaction zone of the pyrolysis chamber, heating the hydrocarbon feedstock at a rate Equal to (4-5) x 10 ⁵ deg / s to the temperature 700-2500 ° C, followed by quenching of the reaction products, characterized in that the high-temperature coolant contains hydrogen in the range of 30-35 vol.% Concentration, and after reaching a the reaction zone temperature of 700-2500 ° C in the reaction stream in two stages, hardening components are introduced and the reaction mixture is cooled with a cooling rate of 1 · 10 ⁵ - 5 · 10 ⁵ deg / s to a temperature level of 600-1300 ° C in the first stage and at a speed cooling 2 · 10 ⁴ - 4 · 10 ⁴ deg / s to a temperature of 300-1000 ° C in the second stage to stop the secondary processes ssov. 2. The method according to claim 1, characterized in that for the generation of a high-temperature coolant as a fuel, a recycled part of the processed raw material is used.