Method for producing chemicals from crude oil by double-tube parallel multi-zone catalytic conversion

Abstract

A method for producing chemicals from crude oil by double-tube parallel multi-zone catalytic conversion is provided. The method may include the following steps: feeding the crude oil directly or separating the crude oil into light and heavy components by flash evaporation or distillation after desalination and dehydration; strengthening the contact and reaction between oil gas and catalyst by using two parallel reaction tubes with novel structure, controlling the reaction by zones, carrying out optimal combination on feeding modes according to different properties of reaction materials, controlling suitable reaction conditions for different materials, and increasing the production of light olefins and aromatics.

Claims

1. A method for producing chemicals from crude oil by double-tube parallel multi-zone catalytic conversion, comprising the following steps: (1) feeding a first raw material at a gas inlet end of a first reaction tube for a cracking reaction in a light alkane reaction zone in the presence of a regenerated catalyst; (2) feeding a preheated second raw material in the middle of the first reaction tube and mixing with materials from the light alkane reaction zone before entering a first heavy oil reaction zone for a cracking reaction, wherein a first oil gas after the cracking reaction and a spent catalyst enter a gas-solid separator for separation, the first oil gas passes through a fractionation system for the separation of light alkanes, light olefins, gasoline, cycle oil and oil slurry, and the gasoline enters an aromatics extraction unit and is separated into aromatics and aromatics raffinate; and the spent catalyst subjected to steam stripping enters a regeneration reactor for regeneration reaction with an oxidant; (3) feeding a third raw material at a gas inlet end of a second reaction tube for a cracking reaction in a gasoline reaction zone in the presence of a regenerated catalyst, wherein the third raw material is a light hydrocarbon or alcohol raw material; and (4) feeding a cycle oil separated in Step (2) or a hydrotreated cycle oil in the middle of the second reaction tube and mixing with materials from the gasoline reaction zone before entering a second heavy oil reaction zone for a cracking reaction to obtain a second oil gas and a spent catalyst, wherein the second oil gas is mixed with the first oil gas to form a resulting mixture, the resulting mixture enters a fractionation system for separation of light alkanes, light olefins, gasoline, cycle oil and oil slurry, and the gasoline enters an aromatics extraction unit and is separated into aromatics and aromatics raffinate; and the spent catalyst subjected to steam stripping enters a regeneration reactor for regeneration reaction with an oxidant.

2. The method according to claim 1, wherein reaction conditions for the light alkane reaction zone are as follows: reaction temperature: 600-800° C., preheating temperature of the first raw material: 40-200° C., mass ratio of catalyst to oil: 5-30, and reaction time: 0.1-5.0 s; reaction conditions for the first heavy oil reaction zone are as follows: reaction temperature: 500-700° C., preheating temperature of the second raw material: 150-250° C., mass ratio of catalyst to oil: 5-30, and reaction time: 0.1-5.0 s; reaction conditions for the gasoline reaction zone are as follows: reaction temperature: 600-800° C., preheating temperature of the third raw material: 40-200° C., mass ratio of catalyst to oil: 5-30, and reaction time: 0.1-5.0 s; and reaction conditions for the second heavy oil reaction zone are as follows: reaction temperature: 500-700° C., preheating temperature of the cycle oil: 200-350° C., mass ratio of catalyst to oil: 5-30, reaction time: 0.1-5.0 s, and reaction temperature of the regeneration reactor: 600-950° C.

3. The method according to claim 1, wherein the first reaction tube and the second reaction tube are downers, risers or composite bed reactors with swirl feed structures; and the first raw material and the third raw material are fed in a swirl feed mode.

4. The method according to claim 1, wherein the second raw material comprises one or more selected from the group consisting of crude oil, heavy components of crude oil, atmospheric gas oil, vacuum gas oil, coking gas oil, atmospheric residual oil, vacuum residual oil, deasphalted oil, oil sands bitumen, shale oil, coal tar, paraffin, plastics, rubber, rubber oil, synthetic oil, and animal and vegetable oils rich in hydrocarbons.

5. The method according to claim 1, wherein in Step (1) and Step (3), the regenerated catalyst comprises a regenerated catalyst from a regenerator or a regenerated catalyst cooler, or a catalyst with temperature or activity changed from a catalyst mixing tank.

6. The method according to claim 1, wherein the first raw material and the third raw material comprise one or more selected from the group consisting of dry gas, light alkanes, alcohols, light components of crude oil, gasoline aromatics raffinate, straight run gasoline, condensate oil, catalytically cracked gasoline, thermal cracking gasoline, coker gasoline, visbreaking gasoline and pyrolysis to ethylene gasoline.

7. The method according to claim 1, wherein the regenerated catalyst comprises one or more selected from the group consisting of microspheres loaded with alkali and/or alkaline earth metals, calcium aluminate, calcium ferrite, magnesia-alumina spinel, silicate aluminate, calcium silicate, magnesium silicate, alumina and semi-coke.

8. The method according to claim 1, wherein the oxidant is one or more selected from the group consisting of oxygen, air, oxygen-rich air, water vapor, carbon dioxide and methane.

9. The method according to claim 1, wherein the regeneration reactor is one selected from the group consisting of a riser regenerator, a turbulent fluidized bed regenerator, a bubbling fluidized bed regenerator, and any combinations thereof.

10. The method according to claim 1, wherein the gas-solid separator is one selected from the group consisting of an inertial separator, a horizontal cyclone separator, a vertical cyclone separator, and any combinations thereof.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) To describe the technical solution in the embodiments in the invention or in the prior art in a more clear way, figures to be used in the embodiments are simply introduced as follows. Apparently, figures in the following description are only some embodiments of the invention, and for a person skilled in the art, other figures may also be obtained based on these figures without paying any creative effort.

(2) FIG. 1 is a schematic diagram of a process flow and a device in Embodiment 1 of the invention.

(3) FIG. 2 is a structural diagram of a riser with swirl feed structure.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(4) Multiple exemplary embodiments of the invention are described in detail. Such detailed description shall not be considered as a limitation of the invention, but shall be understood as a more detailed description of certain aspects, features and embodiments of the invention.

(5) It shall be understood that the terms described in the invention are used only to describe particular embodiments and are not intended to limit the invention. In addition, the range of values in the invention shall be understood to mean that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value in any stated value or within the stated range and each small range between any other stated values or intermediate values within the range are also included in the invention. These small ranges of upper and lower limits may be included or excluded independently.

(6) Unless otherwise stated, all technical and scientific terms used herein have the same meaning that would normally be understood by those of ordinary skill in the art described in the invention. Although the invention only describes the preferred method and material, any method and material similar or equivalent to those described herein may also be used in the implementation or test of the invention. All literatures referred to in the Specification are incorporated by citation to disclose and describe methods and/or materials relevant to the same. In the event of conflict with any incorporated literature, the contents of the Specification shall prevail.

(7) It will be readily apparent to a person skilled in the art that various improvements and variations can be made to the implementation of the Specification of the prevent invention without departing from the scope or spirit of the prevent invention. Other implementations derived from the Specification of the invention are obvious to a person skilled in the art. The Specification and embodiments of the invention are for illustrative purposes only.

(8) The terms “including”, “comprising”, “having” and “containing” used herein are open terms, which means including but not limited to.

(9) A downer (i.e., downward reaction tube), a riser (i.e., upward reaction tube) or a composite bed reaction zone with or without swirl feed structure may be adopted in the tubular reaction zone of the invention, wherein the first raw material and the third raw material can be fed in a swirl feed mode. The structural diagram of a riser with swirl feed structure in the invention is as shown in FIG. 2, a reaction tube body thereof has a total height of 9.2m, a pre-rising section 1 has a diameter of 16 mm and a height of 2.4m; an expanding section 2 has a diameter of 32 mm and a height of 2 m, a necking section 3 has a diameter of 16 mm and a height of 4.6m; a gradual expanding section 4 has a bottom cone angle of 60°, and a gradual expanding section 5 has a top cone angle of 5°. Feed nozzles 6 are tubular, the included angle between a jet direction of a nozzle 6 and the axial direction of the reaction tube body is 30°, and the included angle between the projection direction on a cross section of the reaction tube body and the tangent direction is 60°. There are six nozzles evenly arranged along the circumferential direction of an expanding section 7. Similarly, the structure can also be used in the downer, which can be obtained by a person skilled in the art based on improvements to the riser, and thus will not be described here. The radial speed and circumferential speed of the oil gas and the catalyst are increased by feeding in the expanding sections and using a plurality of injection terminals to increase contact points of oil-catalyst to promote radial mass transfer and heat transfer of the catalyst, achieve rapid and uniform mixing of oil-catalyst, and strengthen the catalytic reaction.

(10) The specific equipment in the catalytic cracking reactor used in the invention, such as regenerator, reaction tube, gas-solid separator, cyclone separator or fractionation system are commonly used in the field of petroleum processing, and can be put into use after proper modification and assembly according to the technological requirements of the invention, which is conducive to industrial implementation.

Embodiment 1

(11) A riser reaction tube with swirl feed structure is taken as an example in the embodiment. After desalination and dehydration, the crude oil is separated into light components and heavy components by boiling points through a flash evaporation or distillation process. Fractions lower than 200° C. are light components, and fractions higher than 200° C. are heavy components.

(12) Referring to the schematic diagram of a process flow and a device shown in FIG. 1, a light alkane 121 is injected from a lower portion of a first riser reactor 102 for contact and reaction with a high temperature regenerated catalyst delivered by a regenerator inclined tube 105 from a regenerator 103 and raised by a pre-rising steam or a rising dry gas 104. After reaction at 600-800° C. under a pressure of 0.1-0.4 MPa with a ratio of catalyst to oil of 5-30 for 0.1-5.0 s, the reaction product leaves a light alkane reaction zone 123 and enters a first heavy oil reaction zone 124. At the bottom of the first heavy oil reaction zone, the reaction product is mixed with a heavy component 101 of the crude oil preheated to 150-250° C. for reaction at 500-700° C. under a pressure of 0.1-0.4 MPa with a ratio of catalyst to oil of 5-30 for 0.1-5.0 s, then the reaction product enters a gas-solid separator 106 and a settler top spin 107 for oil-catalyst separation. The main reaction oil gas 108 enters a fractionating tower for separation of light alkanes, light olefins, gasoline, cycle oil and oil slurry. The gasoline enters an aromatics extraction unit and is separated into aromatics and aromatics raffinate. The spent catalyst enters a stripping stage 110 through a settler 109 for stripping, and then enters a regenerator 103 for burning regeneration. After being preheated to 40-200° C., the separated gasoline aromatics raffinate and a light component 122 of the crude oil enter a gasoline reaction zone 113 of a second riser reactor 112 for contact and reaction with a high temperature regenerated catalyst delivered by a regenerator inclined tube 115 from the regenerator 103, and raised by a pre-rising steam or a rising dry gas 114. After reaction at 600-800° C. under a pressure of 0.1-0.4 MPa with a ratio of catalyst to oil of 5-30 for 0.1-2.0 s, the reaction product enters a second heavy oil reaction zone 116 for contact and reaction with a cycle oil feed 111 preheated to 200-350° C. at the bottom of the second heavy oil reaction zone. After reaction at a reaction temperature of 500-700° C. under a pressure of 0.1-0.4 MPa with a ratio of catalyst to oil of 5-30 for 0.1-5.0 s, the reaction product enters an efficient gas-solid separator 117 and a top spin 107 for oil-catalyst separation. The reaction oil gas 118 and the main reaction oil gas 108 are mixed in the settler 109 and then enter the fractionating tower for separation of light alkanes, light olefins, gasoline, cycle oil and oil slurry. The gasoline enters the aromatics extraction unit and is separated into aromatics and aromatics raffinate. The spent catalyst enters the stripping stage 110 through the settler 109 for stripping, and then enters the regenerator 103 through the stripping stage for burning regeneration. The flue gas leaves the system after being separated from solid particles by the cyclone separator 119. When the coke yield is high, an external regenerated catalyst cooler 120 may be provided to cool the regenerated catalyst.

Embodiment 2

(13) A riser reaction tube with swirl feed structure is adopted, and the crude oil is fed directly.

(14) Referring to the schematic diagram of a process flow and a device shown in FIG. 1, a light alkane 121 is injected from a lower portion of a first riser reactor 102 for contact and reaction with a high temperature regenerated catalyst delivered by a regenerator inclined tube 105 from a regenerator 103 and raised by a pre-rising steam or a rising dry gas 104. After reaction at 600-800° C. under a pressure of 0.1-0.4 MPa with a ratio of catalyst to oil of 5-30 for 0.1-5.0 s, the reaction product leaves a light alkane reaction zone 123 and enters a first heavy oil reaction zone 124. At the bottom of the first heavy oil reaction zone, the reaction product is mixed with the crude oil 101 preheated to 150-250° C. for reaction at 500-700° C. under a pressure of 0.1-0.4 MPa with a ratio of catalyst to oil of 5-30 for 0.1-5.0 s, then the reaction product enters a gas-solid separator 106 and a settler top spin 107 for oil-catalyst separation. The main reaction oil gas 108 enters a fractionating tower for separation of light alkanes, light olefins, gasoline, cycle oil and oil slurry. The gasoline enters an aromatics extraction unit and is separated into aromatics and aromatics raffinate. The spent catalyst enters a stripping stage 110 through a settler 109 for stripping, and then enters a regenerator 103 for burning regeneration. After being preheated to 40-200° C., the separated gasoline aromatics raffinate 122 enters a gasoline reaction zone 113 of a second riser reactor 112 for contact and reaction with a high temperature regenerated catalyst delivered by a regenerator inclined tube 115 from the regenerator 103, and raised by a pre-rising steam or a rising dry gas 114. After reaction at 600-800° C. under a pressure of 0.1-0.4 MPa with a ratio of catalyst to oil of 5-30 for 0.1-2.0 s, the reaction product enters a second heavy oil reaction zone 116 for contact and reaction with a cycle oil feed 111 preheated to 200-350° C. at the bottom of the second heavy oil reaction zone. After reaction at a reaction temperature of 500-700° C. under a pressure of 0.1-0.4 MPa with a ratio of catalyst to oil of 5-30 for 0.1-5.0 s, the reaction product enters an efficient gas-solid separator 117 and a top spin 107 for oil-catalyst separation. The reaction oil gas 118 and the main reaction oil gas 108 are mixed in the settler 109 and then enter the fractionating tower for separation of light alkanes, light olefins, gasoline, cycle oil and oil slurry. The gasoline enters the aromatics extraction unit and is separated into aromatics and aromatics raffinate. The spent catalyst enters the stripping stage 110 through the settler 109, and then enters the regenerator 103 through the stripping stage for burning regeneration. The flue gas leaves the system after being separated from solid particles by the cyclone separator 119. When the coke yield is high, an external regenerated catalyst cooler 120 may be provided to cool the regenerated catalyst.

Embodiment 3

(15) A downer reaction tube with swirl feed structure is adopted. After desalination and dehydration, the crude oil is separated into light components and heavy components by boiling points through a flash evaporation or distillation process. Fractions lower than 200° C. are light components, and fractions higher than 200° C. are heavy components. Refer to Embodiment 1 for the specific process.

Embodiment 4

(16) A downer reaction tube with swirl feed structure is adopted, and the crude oil is fed directly. Refer to Embodiment 2 for the specific process.

Comparative Embodiment 1

(17) Using Daqing crude oil as the raw material and a calcium-based solid base catalyst, a first reaction tube was fed with the crude oil, with a reaction temperature of 620° C. and a reaction time of 1.5 s; and a second reaction tube was fed with cycle oil, with a reaction temperature of 620° C. and a reaction time of 1.8 s.

(18) In order to verify the effect of the invention, the technological process in Embodiments 1-4 and Comparative Embodiment 1 is adopted to carry out a test on a catalytic cracking unit (also referred to as catalytic cracker), and the test results are shown in the table below.

(19) The crude oil used in the test is Daqing crude oil, and the properties of the raw materials are shown in Table 1. The above technological process is adopted, and the raw materials are fed into the catalytic cracking unit according to the process shown in Embodiments 1-4 and Comparative Embodiment 1 for reaction. The specific technological conditions of each reaction zone are shown in Table 2, and the distribution of the resulting products is shown in Table 3. Compared with Comparative Embodiment 1, the process of the invention can increase the yield of ethylene and propylene by about 10%, and the yield of gasoline aromatics by about 8%, and the yield of light olefins and aromatics is significantly increased.

(20) TABLE-US-00001 TABLE 1 General Properties of Crude Oil Daqing crude oil Elemental C 86.14 composition, H 13.21 wt % S 0.26 N 0.19 Naphtha content, wt % 6.62 Metal content, V 0.05 ug .Math. g.sup.−1 Ni 4.26 Carbon residue, wt % 3.2 Density (20° C.), kg .Math. m.sup.−3 870 Boiling range, Initial boiling point ~200° C. 6.62 wt % 200~350° C. 18.47 >350° C. 74.07

(21) TABLE-US-00002 TABLE 2 Contrastive Analysis of Different Processing Schemes Embodiment Embodiment Embodiment Embodiment Comparative Process 1 2 3 4 Embodiment 1 Catalyst Calcium- Calcium- Calcium- Calcium- Calcium- based solid based solid based solid based solid based solid base base base base base Raw material Daqing Daqing Daqing Daqing Daqing crude oil crude oil crude oil crude oil crude oil Gas inlet end Recycle Recycle Recycle Recycle Crude oil of the first light alkanes light alkanes light alkanes light alkanes reaction tube Middle feed Heavy Crude oil Heavy Crude oil inlet of the components components first reaction of crude oil of crude oil tube Gas inlet end Light Recycle Light Recycle Cycle oil of the second components gasoline components gasoline reaction tube of crude oil aromatics of crude oil aromatics and recycle raffinate and recycle raffinate gasoline gasoline aromatics aromatics raffinate raffinate Middle feed Cycle oil Cycle oil Cycle oil Cycle oil inlet of the second reaction tube Operating conditions Temperature 720 720 720 720 of light alkane reaction zone, ° C. Preheating 100 100 100 100 temperature of raw material in the light alkane reaction zone, ° C. Mass ratio of 25 25 25 25 catalyst to oil in the light alkane reaction zone Reaction 0.1 0.1 0.1 0.1 pressure in the light alkane reaction zone, MPa Light alkane 0.8 0.8 0.8 0.8 reaction time, s Temperature 620 620 620 620 620 of the first heavy oil reaction zone, ° C. Preheating 220 220 220 220 220 temperature of raw material in the first heavy oil reaction zone, ° C. Mass ratio of 6 6 6 6 6 catalyst to oil in the first heavy oil reaction zone Reaction 0.1 0.1 0.1 0.1 pressure in the first heavy oil reaction zone, MPa The first heavy 0.8 0.8 0.8 0.8 1.5 oil reaction time, s Temperature 680 680 680 680 of gasoline reaction zone, ° C. Preheating 200 200 200 200 temperature of raw material in the gasoline reaction zone, ° C. Mass ratio of 6 6 6 6 catalyst to oil in the gasoline reaction zone Reaction 0.1 0.1 0.1 0.1 pressure in the gasoline reaction zone, MPa Gasoline 0.6 0.6 0.6 0.6 reaction time, s Temperature 620 620 620 620 620 of the second heavy oil reaction zone, ° C. Preheating 300 300 300 300 300 temperature of raw material in the second heavy oil reaction zone, ° C. Mass ratio of 6 6 6 6 6 catalyst to oil in the second heavy oil reaction zone The second 1.0 1.0 1.0 1.0 1.8 heavy oil reaction time, s Reaction 0.1 0.1 0.1 0.1 0.1 pressure in the second heavy oil reaction zone, MPa

(22) Table 3 Distribution of Main Products

(23) TABLE-US-00003 TABLE 3 Distribution of Main Products Com- Product Embod- Embod- Embod- Embod- parative distribution, iment iment iment iment Embod- wt % 1 2 3 4 iment 1 Gas 78.15 76.47 76.78 76.07 71.92 Dry gas 46.64 45.77 45.32 45.08 43.87 Liquefied 31.51 30.70 31.46 30.99 28.05 petroleum gas Liquid Gasoline 10.41 10.91 10.55 11.00 13.18 Diesel oil 3.58 4.20 3.95 4.50 5.20 Heavy oil 3.71 4.21 3.80 4.30 5.10 Coke 4.16 4.21 4.02 4.13 4.60 Light olefin yield, wt % Ethylene 31.85 31.15 32.01 31.70 25.52 Propylene 21.92 21.32 22.11 21.70 18.70 Butylene 8.17 8.02 8.22 8.15 7.60 Ethylene + 53.76 52.47 54.12 53.40 44.22 propylene Ethylene + 61.93 60.49 62.34 61.55 51.82 propylene + butylene (Ethylene + 68.79 68.62 70.49 70.20 61.48 propylene)/ gas, % (Ethylene + 79.25 79.10 81.19 80.91 72.05 propylene + butylene)/ gas, % Content of 87.5 86.8 87.3 86.9 79.0 aromatics in gasoline, wt %

(24) The above embodiments only describe preferred embodiments of the invention and do not limit the scope of the invention. Without deviating from the design spirit of the invention, all variations and improvements made by those of ordinary skill in the art to the technical solution of the invention shall fall into the protection scope set forth in the Claims of the invention.