System and method for preparing low-carbon hydrocarbon through high-temperature rapid self-thermal decomposition of heavy oil and application

Abstract

The invention provides a system and a method for preparing low-carbon hydrocarbon through high-temperature rapid self-thermal decomposition of heavy oil and application of the system and the method. The system for preparing the low-carbon hydrocarbon through the high-temperature self-thermal decomposition of the heavy oil comprises a feeding unit, a thermal oxygen rapid heating unit, a thermal cracking reaction unit, a rapid cooling unit and a collecting unit, the thermal oxygen rapid heating unit and the feeding unit are connected in parallel and are sequentially connected with the thermal cracking reaction unit, the rapid cooling unit and the collecting unit in series. According to the method, the low-carbon hydrocarbon is prepared through thermal cracking reaction in a thermal oxygen rapid heating mode, external heat supplementation is not needed, and the application scene of preparing basic chemical raw materials from heavy oil is expanded.

Description

Technical Field

[0001] The invention relates to a system, method and application of preparing low-carbon hydrocarbons by high-temperature rapid self-thermal decomposition of heavy oil. Background Art

[0002] my country is short of oil resources and is the world's largest oil importer. With the rapid development of the domestic economy, the demand for oil has increased dramatically. In recent years, the annual import volume of oil has exceeded 500 million tons, and the import amount is more than 150 billion US dollars. A large amount of heavy oil will be produced during the oil processing process. Heavy oil has a high density, high residual carbon content, and high heavy metal content. It is mostly used to obtain light oil products through decarbonization and hydrogenation. In recent years, with the rapid development of new energy vehicles, this is bound to impact the gasoline and diesel markets. There may be overcapacity in the future. The advantage of using heavy oil to produce light oil is no longer there. It is difficult to guarantee the healthy development of enterprises in the future by simply producing gasoline and diesel. Chemical raw materials such as ethylene, propylene, and acetylene have the characteristics of high value, stable price, and high demand. The development of the world economy is inseparable from these basic chemical raw materials. The demand will continue to grow in the future. Therefore, it is imperative for petrochemical enterprises to adjust their industrial structure. In order to achieve higher benefits, they will gradually change from a business model based on oil refining to a business model based on the production of basic chemical products.

[0003] Currently, research on heavy oil cracking is mostly focused on the production of liquid hydrocarbons and coke, and there is little research on small molecular gaseous hydrocarbons. Therefore, it is very important to provide a method and system for high-temperature rapid self-thermal decomposition of heavy oil to produce low-carbon hydrocarbons without external heating and apply it in the industrial field. Summary of the invention

[0004] The technical problem to be solved by the present invention is to overcome the technical defect that small molecular unsaturated gaseous hydrocarbons (such as ethylene) are prone to secondary reactions, and to provide a system, method and application for high-temperature rapid self-thermal decomposition of heavy oil to produce low-carbon hydrocarbons. The present invention realizes high-temperature rapid thermal cracking of heavy oil by connecting a thermal oxygen rapid heating unit in parallel with a feeding unit, and the two are connected in series with a thermal cracking reaction unit, a rapid cooling unit and a collection unit. Rapid heating is achieved by the high-temperature oxygen provided by the thermal oxygen unit and the combustion reaction of the heavy oil to achieve high-temperature thermal cracking of the heavy oil, and then the high-temperature reaction gas is rapidly cooled by a rapid cooling unit to achieve high-temperature rapid self-thermal decomposition of the heavy oil to produce low-carbon hydrocarbons. The present invention provides a system for high-temperature rapid self-thermal decomposition of heavy oil to produce low-carbon hydrocarbons, which does not require external heat supplementation, and expands the application scenarios of high-temperature rapid self-thermal decomposition of heavy oil to produce low-carbon hydrocarbons.

[0005] The present invention solves the above technical problems through the following technical solutions: The present invention provides a system for preparing low-carbon hydrocarbons by high-temperature rapid autothermal decomposition of heavy oil, which comprises a feeding unit, a thermal oxygen rapid heating unit, a thermal cracking reaction unit, a rapid cooling unit and a collecting unit; The thermal oxygen rapid heating unit is connected in parallel with the feeding unit, and the two are connected in series with the thermal cracking reaction unit, the rapid cooling unit and the collecting unit in sequence, and are implemented in the following manner: The top of the heavy oil thermal cracking reaction unit is provided with an inlet burner, which contains a hot oxygen gas inlet and a heavy oil inlet; the bottom of the heavy oil thermal cracking reaction unit is connected to a rapid cooling unit, and a gas outlet, a light oil outlet, and a water and solid product outlet are arranged behind the rapid cooling unit.

[0006] In the present invention, the heavy oil after heating and viscosity reduction and the oxygen heated by the hot oxygen rapid heating unit are introduced into the thermal cracking reaction unit through the top burner to first carry out combustion reaction to achieve the purpose of rapid heating, and then the excess heavy oil undergoes thermal cracking reaction, and the generated reaction gas is introduced into the rapid cooling unit for rapid cooling to simulate a secondary reaction, the generated gas is discharged through the gas outlet, the light oil is discharged through the light oil outlet, and the water and solid products are discharged through the water and solid product outlets.

[0007] In the present invention, preferably, in the system for producing low-carbon hydrocarbons by high-temperature rapid autothermal decomposition of heavy oil, a burner is provided on the top of the thermal cracking reaction unit; The heavy oil feed port and the gas inlet enter the thermal cracking reaction unit through a burner.

[0008] In the present invention, the system for producing low-carbon hydrocarbons by high-temperature rapid autothermal decomposition of heavy oil is characterized in that the main devices of the feeding unit are a heavy oil tank with heating, a stirrer and a heavy oil pump; Wherein, the heavy oil tank (with heating) is arranged before the inlet of the heavy oil thermal cracking reaction unit.

[0009] In the present invention, the system for preparing low-carbon hydrocarbons by high-temperature rapid autothermal decomposition of heavy oil is characterized in that the thermal oxygen rapid heating unit is connected in parallel with the feeding unit and is fed into the thermal cracking reaction unit through a burner; Among them, the hot oxygen rapid heating unit flows oxygen and fuel gas into a chamber together. Since the oxygen is in excess relative to the fuel gas, when the fuel gas is ignited, the excess oxygen is heated and the high-temperature oxygen expands rapidly and then ejected from the chamber outlet.

[0010] In the present invention, the rapid cooling unit in the system for producing low-carbon hydrocarbons by rapid autothermal decomposition of heavy oil at high temperature comprises a quenching jacket and a quenching chamber; Wherein, the quenching jacket is arranged at the connection pipe between the heavy oil thermal cracking reaction unit and the quenching chamber, and the collection unit is connected after the rapid cooling unit; Wherein, water is preferably used as the coolant in the quenching jacket and the cooling chamber.

[0011] In the present invention, the system for producing low-carbon hydrocarbons by high-temperature rapid autothermal decomposition of heavy oil is characterized in that the collection unit includes a gas product collection, a gas flow meter and an analyzer; In the present invention, the heavy oil thermal cracking reaction unit is preferably a catalyst-free fluidized bed reactor, and the inner lining is a refractory brick lining. The hot oxygen rapid heating unit is preferably a unit in which oxygen and fuel gas flow into a chamber together. Since the oxygen is in excess relative to the fuel gas, when the fuel gas is ignited, the excess oxygen is heated and heated, and the high-temperature oxygen expands rapidly and then ejected from the chamber outlet. The rapid cooling unit is preferably a combination of direct cooling and indirect cooling, and the cooling medium is water.

[0012] In the present invention, a method for preparing low-carbon hydrocarbons by high-temperature rapid autothermal decomposition of heavy oil is provided, which adopts the system for preparing low-carbon hydrocarbons by high-temperature rapid autothermal decomposition of heavy oil as described above. The method for preparing low-carbon hydrocarbons by high-temperature rapid autothermal decomposition of heavy oil comprises the following steps: (1) The heavy oil and oxygen undergo a combustion reaction in the thermal cracking reaction unit to provide energy for the thermal cracking reaction; (2) The heavy oil undergoes a thermal cracking reaction in a thermal cracking reaction unit to obtain a reaction gas ①, which includes: H2, CH4, C2H4 and a small amount of C3, C4, etc.; (3) The reaction gas ① reacts again in the rapid cooling unit to obtain reaction gas ②, which includes: H2, CH4, C2H4 and a small amount of C3, C4, etc.

[0013] In the present invention, in step (1), the oxygen comes from the high-temperature oxygen of the thermal oxygen rapid heating unit; the heavy oil comes from the heavy oil heated and reduced in viscosity by the feed unit; And / or, the mass ratio of the oxygen to the heavy oil in step (1) is (0.005-0.045):1, for example 0.025:1; And / or, the temperature of the high-temperature oxygen discharged by the thermal oxygen rapid heating unit is 800-1600° C.; for example, 1300° C.; And / or, the reaction temperature in step (2) is 1200-1400°C, and the reaction residence time is 50 ms-300 ms; for example, the reaction temperature is 1300°C, and the residence time is 200 ms; And / or, the rapid cooling medium in step (3) is water, and the cooling temperature is 25°C.

[0014] In the present invention, preferably, the reaction temperature and residence time are adjusted and controlled by adjusting the mass ratio of the oxygen to the heavy oil.

[0015] On the basis of being in accordance with the common sense in the art, the above-mentioned preferred conditions can be arbitrarily combined to obtain the preferred embodiments of the present invention.

[0016] The positive and progressive effects of the present invention are: (1) The system for producing low-carbon hydrocarbons by high-temperature rapid autothermal decomposition of heavy oil according to the present invention does not require external heating, and no toxic or harmful gases are generated during the reaction; (2) The system for producing low-carbon hydrocarbons by high-temperature rapid autothermal decomposition of heavy oil according to the present invention can greatly improve the conversion rate of low-carbon hydrocarbons; (3) The system for producing low-carbon hydrocarbons by high-temperature rapid autothermal decomposition of heavy oil of the present invention has convenient adjustment of operating parameters, simple and operable device, and can be applied to a variety of application scenarios, especially distributed application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a process flow chart of the system for preparing light hydrocarbons by high-temperature rapid autothermal decomposition of heavy oil according to Example 1, Example 2 and Example 3. The first is the feeding unit, the second is the thermal oxygen rapid heating unit, the third is the thermal cracking reaction unit, the fourth is the rapid cooling unit, and the fifth is the collection unit; 1 is nitrogen, 2 is oxygen, 3 is natural gas, 4 is flow meter, 5 is heavy oil tank with heating, 6 is a stirrer, 7 is a heavy oil pump, 8 is a heating belt, 9 is a hot oxygen generator, 10 is a burner, 11 is a pressure gauge, 12 is an igniter, 13 is a high-temperature endoscope, 14 is a fire viewing hole, 15 is a thermocouple, 16 is a cracking furnace body and refractory lining, 17 is a quenching jacket, 18 is a water quenching chamber, 19 is a solid product collection tank, 20 is a light oil collection tank, 21 is a gas flow meter, 22 is an online analyzer, 23 is a computer, 24 is an electronic scale, ① is the reaction gas out of the cracking furnace, and ② is the reaction gas out of the quenching chamber. DETAILED DESCRIPTION

[0018] The present invention is further described below by way of examples, but the present invention is not limited to the scope of the examples. The experimental methods in the following examples without specifying specific conditions are carried out according to conventional methods and conditions, or selected according to the product specifications. Example

[0019] like Figure 1 Shown is a process flow chart of a system for producing light hydrocarbons by high-temperature rapid autothermal decomposition of heavy oil in this embodiment.

[0020] This embodiment provides a system for producing low-carbon hydrocarbons by rapid autothermal decomposition of heavy oil at high temperature.

[0021] A system for producing low-carbon hydrocarbons by high-temperature rapid autothermal decomposition of heavy oil comprises a feed unit 1, a thermal oxygen rapid heating unit 2, a thermal cracking reaction unit 3, a rapid cooling unit 4 and a collection unit 5; the thermal cracking reaction unit is a catalyst-free fluidized bed reactor type, and its inner lining is a refractory brick lining.

[0022] This embodiment also provides a method for producing low-carbon hydrocarbons by high-temperature rapid autothermal decomposition of the heavy oil, which comprises the following steps: (1) Pass the nitrogen in 1 into the reaction furnace to exhaust the air in the furnace; (2) The natural gas in 3 and the oxygen in 2 are introduced into a hot oxygen generator 9 to heat the oxygen to 1600°C; (3) The heavy oil in the heavy oil tank 5 and the oxygen in the hot oxygen generator 9 are simultaneously introduced into the burner and ignited by the igniter 12 to carry out the heavy oil combustion reaction to achieve the purpose of rapid temperature increase. At the same time, the excess heavy oil undergoes a thermal cracking reaction to generate reaction gas ①, which includes: H2, CH4, C2H4 and a small amount of C3, C4, etc.; (4) The generated reaction gas ① is introduced into a pipeline with a quenching jacket 17, and then introduced into a water quenching chamber 18 to suppress secondary reactions. The generated solid product is introduced into a solid product collection tank 19, and the generated light oil is introduced into a light oil collection tank 20 to generate reaction gas ②. The reaction gas ② includes: H2, CH4, C2H4 and a small amount of C3, C4, etc. The main components of the generated gas are analyzed by an online analyzer 22, and the gas flow meter 21 determines the flow rate of the generated gas.

[0023] In the above steps, the mass ratio of oxygen to heavy oil in the burner is 0.027:1, the reaction temperature is controlled to be 1300°C, and the residence time is 200ms.

[0024] Example 1 The process of high-temperature rapid autothermal decomposition of heavy oil to produce light hydrocarbons does not require external supply of additional heat, and no toxic or harmful gases are generated during the reaction. The gas phase yield is 15.34%, of which the yield of light hydrocarbons (CH4 and C2H4) accounts for 82.79%, and the remaining gases account for 17.21%; the light oil yield is 21.53%; and the solid yield is 63.13%. Example

[0025] like Figure 1 Shown is a process flow chart of a system for producing light hydrocarbons by high-temperature rapid autothermal decomposition of heavy oil in this embodiment.

[0026] This embodiment provides a system for producing low-carbon hydrocarbons by rapid high-temperature autothermal decomposition of heavy oil.

[0027] A system for producing low-carbon hydrocarbons by high-temperature rapid autothermal decomposition of heavy oil comprises a feed unit 1, a thermal oxygen rapid heating unit 2, a thermal cracking reaction unit 3, a rapid cooling unit 4 and a collection unit 5; the thermal cracking reaction unit is a catalyst-free fluidized bed reactor type, and its inner lining is a refractory brick lining.

[0028] This embodiment also provides a method for producing low-carbon hydrocarbons by high-temperature rapid autothermal decomposition of the heavy oil, which comprises the following steps: (1) Pass the nitrogen in 1 into the reaction furnace to exhaust the air in the furnace; (2) The natural gas in 3 and the oxygen in 2 are introduced into a hot oxygen generator 9 to heat the oxygen to 1600°C; (3) The heavy oil in the heavy oil tank 5 and the oxygen in the hot oxygen generator 9 are simultaneously introduced into the burner and ignited by the igniter 12 to carry out the heavy oil combustion reaction to achieve the purpose of rapid temperature increase. At the same time, the excess heavy oil undergoes a thermal cracking reaction to generate reaction gas ①, which includes: H2, CH4, C2H4 and a small amount of C3, C4, etc.; (4) The generated reaction gas ① is introduced into a pipeline with a quenching jacket 17, and then introduced into a water quenching chamber 18 to suppress secondary reactions. The generated solid product is introduced into a solid product collection tank 19, and the generated light oil is introduced into a light oil collection tank 20 to generate reaction gas ②. The reaction gas ② includes: H2, CH4, C2H4 and a small amount of C3, C4, etc. The main components of the generated gas are analyzed by an online analyzer 22, and the gas flow meter 21 determines the flow rate of the generated gas.

[0029] In the above steps, the mass ratio of oxygen to heavy oil in the burner is 0.036:1, the reaction temperature is controlled to be 1400°C, and the residence time is 200ms.

[0030] Example 2 The process of high-temperature rapid autothermal decomposition of heavy oil to produce light hydrocarbons does not require additional external heat, and no toxic or harmful gases are generated during the reaction. The gas phase yield is 16.44%, of which the light hydrocarbon yield accounts for 86.29%, and the remaining gas accounts for 13.71%; the light oil yield is 23.98%; and the solid yield is 59.58%. Example

[0031] like Figure 1 Shown is a process flow chart of a system for producing light hydrocarbons by high-temperature rapid autothermal decomposition of heavy oil in this embodiment.

[0032] This embodiment provides a system for producing low-carbon hydrocarbons by rapid autothermal decomposition of heavy oil at high temperature.

[0033] A system for producing low-carbon hydrocarbons by high-temperature rapid autothermal decomposition of heavy oil comprises a feed unit 1, a thermal oxygen rapid heating unit 2, a thermal cracking reaction unit 3, a rapid cooling unit 4 and a collection unit 5; the thermal cracking reaction unit is a catalyst-free fluidized bed reactor type, and its inner lining is a refractory brick lining.

[0034] This embodiment also provides a method for producing low-carbon hydrocarbons by high-temperature rapid autothermal decomposition of the heavy oil, which comprises the following steps: (1) Pass the nitrogen in 1 into the reaction furnace to exhaust the air in the furnace; (2) The natural gas in 3 and the oxygen in 2 are introduced into a hot oxygen generator 9 to heat the oxygen to 1600°C; (3) The heavy oil in the heavy oil tank 5 and the oxygen in the hot oxygen generator 9 are simultaneously introduced into the burner and ignited by the igniter 12 to carry out the heavy oil combustion reaction to achieve the purpose of rapid temperature increase. At the same time, the excess heavy oil undergoes a thermal cracking reaction to generate reaction gas ①, which includes: H2, CH4, C2H4 and a small amount of C3, C4, etc.; (4) The generated reaction gas ① is passed into a pipeline with a quenching jacket 17, and then into a water quenching chamber 18 to suppress secondary reactions. The generated solid product is passed into a solid product collection tank 19, and the generated light oil is passed into a light oil collection tank 20 to generate reaction gas ②. The reaction gas ② includes: H2, CH4, C2H4 and a small amount of C3, C4, etc. The main components of the generated gas are analyzed by an online analyzer 22, and the gas flow rate is measured by a gas flow meter 21.

[0035] In the above steps, the mass ratio of oxygen to heavy oil in the burner is 0.027:1, the reaction temperature is controlled to be 1300°C, and the residence time is 300ms.

[0036] Example 3 The process of high-temperature rapid autothermal decomposition of heavy oil to produce light hydrocarbons does not require external supply of additional heat, and no toxic or harmful gases are generated during the reaction. The gas phase yield is 14.89%, of which the light hydrocarbon yield accounts for 83.65%, and the remaining gas accounts for 16.35%; the light oil yield is 23.46%; and the solid yield is 61.65%.

Claims

1. A system for producing low-carbon hydrocarbons by rapid autothermal decomposition of heavy oil at high temperature, characterized in that: It includes a feeding unit, a thermal oxygen rapid heating unit, a thermal cracking reaction unit, a rapid cooling unit and a collecting unit; The thermal oxygen rapid heating unit is connected in parallel with the feeding unit, and the two are connected in series with the thermal cracking reaction unit, the rapid cooling unit and the collecting unit in sequence, and are implemented in the following manner: The top of the heavy oil thermal cracking reaction unit is provided with an inlet burner, which contains a hot oxygen gas inlet and a heavy oil inlet; the bottom of the heavy oil thermal cracking reaction unit is connected to a rapid cooling unit, and the rapid cooling unit is provided with a gas outlet, a light oil outlet, and a water and solid product outlet.

2. The system for producing low-carbon hydrocarbons by high-temperature rapid autothermal decomposition of heavy oil as claimed in claim 1, characterized in that: A burner is provided on the top of the thermal cracking reaction unit; The heavy oil feed port and the gas inlet enter the thermal cracking reaction unit through a burner.

3. The system for producing light hydrocarbons by high-temperature rapid autothermal decomposition of heavy oil as claimed in claim 1 or 2, characterized in that: The main devices of the feeding unit are a heavy oil tank with heating, a stirrer and a heavy oil pump; The heavy oil tank (with heating) is arranged before the inlet of the heavy oil thermal cracking reaction unit.

4. The system for producing low-carbon hydrocarbons by high-temperature rapid autothermal decomposition of heavy oil as claimed in claim 1 or 2, characterized in that: The hot oxygen rapid heating unit is connected in parallel with the feeding unit and is fed into the thermal cracking reaction unit through a burner; The hot oxygen rapid heating unit flows oxygen and fuel gas into a chamber together. Since the oxygen is in excess relative to the fuel gas, when the fuel gas is ignited, the excess oxygen is heated and heated, and the high-temperature oxygen expands rapidly and then is ejected from the chamber outlet.

5. The system for producing low-carbon hydrocarbons by high-temperature rapid autothermal decomposition of heavy oil as claimed in claim 1, wherein the rapid cooling unit in the system for producing low-carbon hydrocarbons by high-temperature rapid autothermal decomposition of heavy oil comprises a quenching jacket and a quenching chamber.

6. The system for producing low-carbon hydrocarbons by high-temperature rapid autothermal decomposition of heavy oil as claimed in claim 5, characterized in that: The quenching jacket is arranged at the connection pipe between the thermal cracking reaction unit and the quenching chamber, and the collection unit is connected after the rapid cooling unit; The cooling jacket and the cooling chamber preferably use water as the cooling liquid.

7. The system for producing low-carbon hydrocarbons by high-temperature rapid autothermal decomposition of heavy oil as claimed in claim 1 or 6, characterized in that: The collection unit includes a gas product collection unit, a gas flow meter and an analyzer.

8. A method for preparing low-carbon hydrocarbons by rapid autothermal decomposition of heavy oil at high temperature, characterized in that: The system for preparing low-carbon hydrocarbons by high-temperature rapid autothermal decomposition of heavy oil as claimed in any one of claims 1 to 7 is adopted, and the method for preparing low-carbon hydrocarbons by high-temperature rapid autothermal decomposition of heavy oil comprises the following steps: (1) The heavy oil and oxygen undergo a combustion reaction in the thermal cracking reaction unit to provide energy for the thermal cracking reaction; (2) The heavy oil undergoes a thermal cracking reaction in the thermal cracking reaction unit to obtain a reaction gas ①, which includes: H2, CH4, C2H4 and a small amount of C3, C4, etc.; (3) The reaction gas ① is rapidly cooled in a rapid cooling unit to suppress the secondary reaction of unsaturated hydrocarbons, thereby obtaining a reaction gas ②. The reaction gas ② includes: H2, CH4, C2H4 and a small amount of C3, C4, etc.

9. A method for preparing light hydrocarbons by high-temperature rapid autothermal decomposition of heavy oil as claimed in claim 8, characterized in that: In step (1), the oxygen comes from the high-temperature oxygen of the hot oxygen rapid heating unit; the heavy oil comes from the heavy oil heated and reduced in viscosity by the feed unit; And / or, the mass ratio of the oxygen to the heavy oil in step (1) is (0.005-0.045): 1; And / or, the temperature of the high-temperature oxygen discharged by the thermal oxygen rapid heating unit is 800-1600°C; And / or, the reaction temperature in step (2) is 1200-1400°C, and the reaction residence time is 50 ms-300 ms; And / or, the rapid cooling medium in step (3) is water, and the cooling temperature is 25°C.

10. Use of the system for producing light hydrocarbons by high-temperature rapid autothermal decomposition of heavy oil as claimed in any one of claims 1 to 7 in the field of producing light hydrocarbons.

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