阅读说明：本技术 一种油砂沥青超临界水热减黏的方法 (Supercritical hydrothermal viscosity reduction method for oil sand asphalt ) 是由 王丽涛 李永红 许倩 刘志远 张艳梅 宇富航 刘银东 韩爽 卢竟蔓 于志敏 张浩 于 2019-03-15 设计创作，主要内容包括：一种油砂沥青超临界水热减黏的方法,其特征是在超临界水热条件下对油砂沥青进行两级水热反应,第一级反应完成之后利用釜内的高压将釜内的水和轻油产物释放到收集装置,继续向反应器内注水,升温至水的超临界态,使得反应器内残留的油砂沥青和一段反应生成的焦发生水热裂解反应,达到提高轻油收率和除焦的目的。利用该方法处理重油不仅能大幅度提高重油转化率还能显著抑制或完全避免体系的结焦现象。(A supercritical hydrothermal viscosity reduction method for oil sand asphalt is characterized in that two-stage hydrothermal reaction is carried out on the oil sand asphalt under the supercritical hydrothermal condition, water and light oil products in a kettle are released to a collection device by utilizing high pressure in the kettle after first-stage reaction is finished, water is continuously injected into a reactor, and the temperature is raised to the supercritical state of the water, so that hydrothermal cracking reaction is carried out on residual oil sand asphalt in the reactor and coke generated by one-stage reaction, and the purposes of improving the yield of the light oil and removing the coke are achieved. The method for treating the heavy oil can not only greatly improve the conversion rate of the heavy oil, but also obviously inhibit or completely avoid the coking phenomenon of the system.)

1. A supercritical hydrothermal visbreaking method for oil sand asphalt comprises the following steps:

carrying out two-stage or multi-stage modification reaction on an oil sand asphalt raw material under a supercritical hydrothermal condition, wherein the reaction time of each stage is 15-30 min, the stirring speed is 30-60 r/min, after the first-stage supercritical hydrothermal reaction is finished, a valve at the top of a reactor is opened, vaporized oil-water mixed materials are quickly discharged depending on the temperature and pressure in the reactor, condensed by a heat exchanger and collected in a receiving container at room temperature, an oil phase and a water phase are separated, the oil phase is a light oil product of the first-stage supercritical hydrothermal reaction, and the water phase is recycled;

injecting water into the reactor for the second time immediately after the vaporized oil-water mixed material is discharged, so that the residual material in the reactor is subjected to a second-stage supercritical hydrothermal reaction to generate a viscosity-reduced light oil product of the second-stage supercritical hydrothermal reaction, and simultaneously achieving the aim of decoking;

according to the requirements of viscosity property and viscosity reduction degree of the oil sand asphalt raw material, adding multi-stage supercritical hydrothermal reaction after the second-stage supercritical hydrothermal reaction;

then, washing the reactor with toluene, filtering out toluene insoluble substances, and separating and recovering toluene to obtain an eluate;

and mixing the light oil product obtained through the two-stage or multi-stage reaction with the eluate to obtain the viscosity-reduced oil of the oil sand asphalt.

2. The supercritical hydrothermal viscosity reduction method for oil sand bitumen according to claim 1, comprising the following steps:

(1) preheating the reactor to 80-90 ℃, adding water and oil sand asphalt, heating and stirring, heating to 390-420 ℃, keeping the temperature constant for 15-30 min under the autogenous pressure state, and carrying out a first-stage supercritical hydrothermal reaction;

(2) stopping heating, starting a valve to discharge vaporized materials in the reaction kettle, condensing the materials through heat exchange, and then conveying the materials to a liquid receiving tank to separate an oil phase and a water phase, wherein the oil phase is a light oil product of a first-stage supercritical hydrothermal reaction, and the water phase is circulated to the reactor;

(3) after the vaporized oil-water mixed material is discharged, rapidly injecting water into the reactor for the second time, starting stirring, supplementing the injected water when the temperature of the reaction kettle is reduced to 200-300 ℃, heating the reactor to raise the temperature to 380-400 ℃, keeping the temperature constant for 15-30 min under a self-boosting state, and performing supercritical hydrothermal reaction on the residual material in the reactor for the second time;

(4) obtaining light oil products of the second-stage supercritical hydrothermal reaction according to the operation of the step (2),

according to the requirements of viscosity property and viscosity reduction degree of the oil sand asphalt raw material, adding multi-stage supercritical hydrothermal reaction after the second-stage supercritical hydrothermal reaction;

(5) then, washing the reactor with toluene at 100-150 ℃, filtering out toluene insoluble substances, and separating and recovering toluene to obtain an eluate;

(6) and mixing the light oil product obtained through the two-stage reaction or the multi-stage reaction with the eluate to obtain the viscosity-reduced oil of the oil sand asphalt.

3. The supercritical hydrothermal visbreaking method for oil sand bitumen as claimed in claim 1 or 2, characterized in that: the reaction temperature of the first-stage supercritical hydrothermal reaction is 390-400 ℃.

4. The supercritical hydrothermal visbreaking method for oil sand bitumen as claimed in claim 1 or 2, characterized in that: the reaction temperature of the second-stage supercritical hydrothermal reaction is 390-400 ℃.

5. The supercritical hydrothermal visbreaking method for oil sand bitumen as claimed in claim 1 or 2, characterized in that: in the first-stage supercritical hydrothermal reaction, the mass ratio of the first-stage water injection amount to the oil sand asphalt raw material is 0.5: 1-2: 1.

6. The supercritical hydrothermal visbreaking method for oil sand bitumen as claimed in claim 5, characterized in that: in the first-stage supercritical hydrothermal reaction, the mass ratio of the first-stage water injection amount to the oil sand asphalt raw material is 1: 1-2: 1.

7. The supercritical hydrothermal visbreaking method for oil sand bitumen as claimed in claim 1 or 2, characterized in that: in the second-stage supercritical hydrothermal reaction, the second-time water injection amount accounts for 50-100% of the weight of the oil sand asphalt raw material.

8. The supercritical hydrothermal visbreaking method for oil sand bitumen as claimed in claim 1 or 2, characterized in that: and the light oil product of the first-stage supercritical hydrothermal reaction accounts for 60-80% of the weight of the oil sand asphalt raw material.

9. The supercritical hydrothermal visbreaking method for oil sand bitumen as claimed in claim 1 or 2, characterized in that: the remaining material in the reactor includes residual oil sand bitumen and coke formed in the first stage of the reaction.

Technical Field

The invention relates to a supercritical hydrothermal modification method for oil sand asphalt, which mainly utilizes two-stage supercritical hydrothermal reaction to improve the viscosity reduction effect of the oil sand asphalt and inhibit coking. The invention belongs to the technical field of petroleum processing.

Background

In recent years, rapid development of human society is not supported by fossil energy, and petroleum resources are currently used as the most widely demanded energy, and the reserves thereof are decreasing and the quality thereof is becoming more and more important. At present, oil sand bitumen, super heavy oil and other heavy oil products are used as one of the most energy sources in the world, the global storable and recoverable amount is about 4000 hundred million tons, which is 2.7 times of that of conventional crude oil, so that how to more reasonably and effectively utilize the heavy oil products is important in the key period that the current energy demand is continuously increased and the novel energy sources are not enough to comprehensively meet the social demand.

Although the existing heavy oil treatment processes such as hydrocracking, catalytic cracking, delayed coking and the like can effectively process and treat heavy oil, the production and environmental protection requirements of the technologies are increasingly not met due to inherent defects of the technologies in the aspects of economy, environmental protection, heavy oil utilization rate and the like. The supercritical hydrothermal upgrading process is a novel environment-friendly green process, and the basic idea is that the supercritical hydrothermal upgrading process is used as a solvent and a dispersant for heavy oil upgrading by utilizing the characteristic that water has high solubility to organic matters under a supercritical condition. Under the supercritical water-heat condition, small molecular hydrocarbons and macromolecular radical fragments generated by heavy oil cracking are continuously transferred from the oil phase to the supercritical water phase, so that the macromolecular radical fragments which are easy to collide with each other and coke are well dispersed in the supercritical water phase, and the heavy oil is continuously cracked into hydrocarbons with smaller molecular weight. In addition, the supercritical hydrothermal modification process of the heavy oil also has the effects of desulfurization, denitrification and reduction of heavy metal content.

Although the supercritical hydrothermal upgrading process has good effects on heavy oil upgrading effect, heavy oil conversion rate and heteroatom removal, the development of the process is limited to a certain extent due to the harsh reaction conditions and the easy coking of the reaction system.

The patent US7740065B2 discloses a method for upgrading full-component crude oil by using high-pressure hot water and reflux fluid, which mainly recycles the fluid recovered in the process of crude oil upgrading to improve the extraction rate of crude oil, and re-upgrades the heavy component obtained after the extracted crude oil is flashed under the condition of supercritical water, wherein the reflux fluid in the method is mainly CO₂、N₂、CH₄And steam. Although the method can improve the extraction rate and the upgrading effect of crude oil, the pressure resistance and corrosion resistance requirements on equipment and pipelines are increased due to the use of the pressurized recovery fluid.

Patent CN101970611A and patent CN102834489A disclose a method for upgrading heavy oil by hot pressurized water and an ultrasonic wave generating premixer and a method for mixing water, oxidant and heavy oil under supercritical temperature and pressure conditions and finally subjecting the mixture to microwave treatment, respectively, which mainly utilize ultrasonic wave or the combined action of oxidant and ultrasonic wave to promote the mixing of oil-water two phases and heavy oil cracking. Wherein the oxidant described in patent CN102834489A is selected from solid additives such as oxygen, air, hydrogen peroxide, organic peroxide, inorganic superoxide, sulfuric acid, nitric acid, etc.

Patent CN104039434A discloses a supercritical water process for upgrading petroleum by adding a starter to the supercritical water process for upgrading petroleum to promote mixing of petroleum feedstock and water, thereby reducing or eliminating the production of coke, coke precursors and slurry, wherein the starter is selected from the group consisting of benzene, toluene, xylene and ethylbenzene.

Patent CN 108495915 a discloses a supercritical water upgrading process for producing paraffinic streams from heavy oil. The method adopts a method of connecting two reactors in series, firstly supercritical water flow and petroleum-based composition after pressurization and heating are mixed and enter a first reactor to carry out partial reaction, and then a product of the first reactor is led out to a second reactor to carry out continuous reaction, thereby obtaining a target product.

Patent CN 101077980 a discloses a method for preparing light oil by supercritical water upgrading vacuum residue. The method adopts a kettle type heater or a tubular reactor, water and residual oil raw materials are added into the reactor, the temperature and the pressure are raised to a certain value for carrying out primary reaction, and the reactor is cooled after the reaction is finished to separate reaction products.

Patent CN 108251154 a discloses a heavy oil visbreaking method based on supercritical benzene and its application. The method refers to placing heavy oil in a supercritical benzene environment in a specific thermodynamic state, so that visbreaking of the heavy oil is carried out from high viscosity to the supercritical benzene, and how to realize the specific supercritical benzene environment is not clear.

Patent CN1325605C discloses a method for treating oil sand bitumen, which comprises adding solvent into oil sand bitumen to remove bitumen, and then cracking, wherein the solvent in the method is hydrocarbons of C3-C5.

Patent CN1195822C discloses a viscosity breaking method for deoiled asphalt, which adds 1-50% of catalytic cracking clarified oil into deoiled asphalt to improve the cracking effect by reducing the viscosity of the deoiled asphalt.

Patent CN107022373A discloses a process for reducing viscosity of heavy oil by hydrothermal cracking, which uses cracked light components as new diluent to mix with heavy oil to reduce its viscosity, and then shallow hydrothermal cracking is performed.

Patent CN106753509A discloses a visbreaking treatment method for blending oil sand asphalt with coal tar distillate.

Patent CN101597511B discloses an extra heavy crude oil upgrading process, which is to mix extra heavy crude oil with diluent, and send the mixture into a catalytic cracking reactor for cracking reaction under the action of catalyst, wherein the diluent comprises: propane, butane, pentane, hexane.

Patent CN106701161A discloses a heavy oil upgrading system and method using acoustic cavitation in cooperation with hydrogen donor, the method mainly uses acoustic waves to promote the mixing of heavy oil and light-providing agent to improve the heavy oil upgrading effect, the light-providing agent includes: dihydronaphthalene, tetrahydronaphthalene, decahydronaphthalene and dihydrophenanthrene.

U.S. Pat. No. 4298455 discloses a process for reducing viscosity of heavy oil by adding chain transfer agent and initiator to the reaction system to promote cracking of heavy oil, wherein the chain transfer agent is tetrachloride and the initiator is diisobutyronitrile and benzoyl peroxide, and no plant-based solid additive is included.

Patent CN102086411A discloses a method for preparing light oil by using alkali to modify heavy oil under hydrothermal condition, patent CN102093913A discloses a method for co-treating glycerin and heavy oil hydrothermally and simultaneously obtaining lactic acid and light oil, and the method mainly uses alkali liquor to promote co-cracking of glycerin and heavy oil to produce lactic acid and light oil. The alkali in the above two methods is ammonia water, Ca (OH)₂NaOH or KOH.

The invention carries out two-stage or multi-stage modification reaction on heavy oil under the supercritical hydrothermal condition, and recovers heavy oil cracking products in time, and then adds water to enable the unreacted heavy oil to continue to react, thereby achieving the effect of greatly improving the heavy oil conversion rate and simultaneously inhibiting or completely avoiding the system coking.

Disclosure of Invention

The invention provides a supercritical hydrothermal viscosity reduction method for oil sand asphalt, aiming at solving the problems of harsh reaction conditions, low conversion rate, easy coking of a system and the like of the current supercritical hydrothermal modification process for heavy oil. The method mainly comprises the steps of carrying out two-stage or multi-stage hydrothermal reaction on the oil sand asphalt under the supercritical hydrothermal condition, timely removing small molecular components generated by the first-stage reaction out of a reaction area, reducing the coke generation amount, and eliminating coke generated by the first-stage reaction through the second-stage reaction. The method can improve the conversion rate of the viscosity-reducing reaction of the oil sand asphalt and avoid the coking phenomenon of the system.

The invention provides a supercritical hydrothermal viscosity reduction method for oil sand asphalt, which comprises the following steps:

carrying out two-stage or multi-stage modification reaction on an oil sand asphalt raw material under a supercritical hydrothermal condition, wherein the reaction time of each stage is 15-30 min, the stirring speed is 30-60 r/min, after the first-stage supercritical hydrothermal reaction is finished, a valve at the top of a reactor is opened, vaporized oil-water mixed materials are quickly discharged depending on the temperature and pressure in the reactor, condensed by a heat exchanger and collected in a receiving container at room temperature, an oil phase and a water phase are separated, the oil phase is a light oil product of the first-stage supercritical hydrothermal reaction, and the water phase is recycled;

injecting water into the reactor for the second time immediately after the vaporized oil-water mixed material is discharged, so that the residual material in the reactor is subjected to a second-stage supercritical hydrothermal reaction to generate a viscosity-reduced light oil product of the second-stage supercritical hydrothermal reaction, and simultaneously achieving the aim of decoking;

according to the requirements of viscosity property and viscosity reduction degree of the oil sand asphalt raw material, adding multi-stage supercritical hydrothermal reaction after the second-stage supercritical hydrothermal reaction;

then, washing the reactor with toluene, filtering out toluene insoluble substances, and separating and recovering toluene to obtain an eluate;

and mixing the light oil product obtained through the two-stage or multi-stage reaction with the eluate to obtain the viscosity-reduced oil of the oil sand asphalt.

The supercritical hydrothermal viscosity reduction method for oil sand asphalt provided by the invention specifically comprises the following steps:

(1) preheating the reactor to 80-90 ℃, adding water and oil sand asphalt, heating and stirring, heating to 390-420 ℃, keeping the temperature constant for 15-30 min under the autogenous pressure state, and carrying out a first-stage supercritical hydrothermal reaction;

(2) stopping heating, starting a valve to discharge vaporized materials in the reaction kettle, condensing the materials through heat exchange, and then conveying the materials to a liquid receiving tank to separate an oil phase and a water phase, wherein the oil phase is a light oil product of a first-stage supercritical hydrothermal reaction, and the water phase is circulated to the reactor;

(3) after the vaporized oil-water mixed material is discharged, rapidly injecting water into the reactor for the second time, starting stirring, supplementing the injected water when the temperature of the reaction kettle is reduced to 200-300 ℃, heating the reactor to raise the temperature to 380-400 ℃, keeping the temperature constant for 15-30 min under a self-boosting state, and performing supercritical hydrothermal reaction on the residual material in the reactor for the second time;

(4) obtaining light oil products of the second-stage supercritical hydrothermal reaction according to the operation of the step (2),

according to the requirements of viscosity property and viscosity reduction degree of the oil sand asphalt raw material, adding multi-stage supercritical hydrothermal reaction after the second-stage supercritical hydrothermal reaction;

(5) then, washing the reactor with toluene at 100-150 ℃, filtering out toluene insoluble substances, and separating and recovering toluene to obtain an eluate;

(6) and mixing the light oil product obtained through the two-stage reaction or the multi-stage reaction with the eluate to obtain the viscosity-reduced oil of the oil sand asphalt.

The invention provides a supercritical hydrothermal viscosity reduction method for oil sand asphalt, which comprises the following steps: the reaction temperature of the first-stage supercritical hydrothermal reaction is 390-400 ℃.

The invention provides a supercritical hydrothermal viscosity reduction method for oil sand asphalt, which comprises the following steps: the reaction temperature of the second-stage supercritical hydrothermal reaction is 390-400 ℃.

The invention provides a supercritical hydrothermal viscosity reduction method for oil sand asphalt, which comprises the following steps: in the first-stage supercritical hydrothermal reaction, the mass ratio of the first-stage water injection amount to the oil sand asphalt raw material is 0.5: 1-2: 1.

The invention provides a supercritical hydrothermal viscosity reduction method for oil sand asphalt, which comprises the following steps: in the first-stage supercritical hydrothermal reaction, the mass ratio of the first-stage water injection amount to the oil sand asphalt raw material is 1: 1-2: 1.

The invention provides a supercritical hydrothermal viscosity reduction method for oil sand asphalt, which comprises the following steps: in the second-stage supercritical hydrothermal reaction, the second-time water injection amount accounts for 50-100% of the weight of the oil sand asphalt raw material.

The invention provides a supercritical hydrothermal viscosity reduction method for oil sand asphalt, which comprises the following steps: and the light oil product of the first-stage supercritical hydrothermal reaction accounts for 60-80% of the weight of the oil sand asphalt raw material.

The invention provides a supercritical hydrothermal viscosity reduction method for oil sand asphalt, which comprises the following steps: the remaining material in the reactor includes residual oil sand bitumen and coke formed in the first stage of the reaction.

The invention can be described as follows:

the invention provides a supercritical hydrothermal viscosity reduction method for oil sand asphalt, which comprises the following steps: placing oil sand asphalt in a supercritical hydrothermal environment for a certain time to decompose macromolecules in the oil sand asphalt into smaller molecules, performing two-stage or multi-stage modification reaction at 390-420 ℃ under the self-boosting condition of an oil-water mixture system, wherein the reaction time of each stage is 15-30 min, after the first-stage reaction is finished, opening a valve at the top of a reactor, quickly discharging vaporized oil-water mixed materials by depending on the temperature and pressure in the reactor, condensing the discharged materials through a heat exchanger, collecting the condensed materials in a receiving container at room temperature, standing to separate an oil phase and a water phase, wherein the oil phase is a viscosity reduction product of the first-stage reaction, recycling the water phase, immediately injecting water into the reactor after the vaporized oil-water mixed materials are discharged, sealing the reactor, performing a second-stage reaction to enable heavy components remaining in the reactor and coke generated by the first-stage reaction to perform a hydrothermal cracking reaction to generate a viscosity reduction second-stage reaction product, simultaneously achieves the aim of decoking. Multiple stages of reaction can be added after the second stage of reaction as required by the viscosity properties of the feedstock and the degree of viscosity reduction.

The invention provides a preferable supercritical hydrothermal viscosity reduction method for oil sand asphalt, which mainly comprises the following steps:

(1) the reactor is preheated to 80-90 ℃, and water and oil sand bitumen are added. Heating and stirring, wherein the temperature is increased to 390-420 ℃, the autogenous pressure is 20-27 MPa, and the temperature is kept constant for 15-30 min under the condition;

(2) stopping heating, opening a valve to discharge vaporized materials in the reaction kettle, carrying out heat exchange and condensation, then sending the materials to a liquid receiving tank, standing or centrifugally separating an oil phase and a water phase, wherein the oil phase is a light oil product of the first-stage reaction, and the water phase is circulated to the reactor;

(3) after the vaporized materials are discharged, quickly injecting a small amount of water into the reactor for the second time, starting stirring, supplementing the injected water when the temperature of the reaction kettle is reduced to 200-300 ℃, heating the reactor to raise the temperature to 380-400 ℃, and keeping the temperature constant for 15-30 min under the self-boosting state;

(4) obtaining a light oil product of the second-stage reaction according to the operation of the step (2);

(5) washing the reactor with toluene at 100-150 ℃, filtering out toluene insoluble substances, and separating and recovering toluene to obtain an eluate;

(6) and mixing the light oil product obtained by the two-stage reaction with the toluene eluate to obtain the viscosity-reduced oil of the oil sand asphalt.

In the invention, the recommended reaction stirring speed of each stage is 30-60 r/min.

In step (5), it is recommended to use rotary evaporation to separate toluene and the eluate.

In the invention, the preferable first-stage reaction temperature is 390-400 ℃,

in the invention, the preferable secondary reaction temperature is 390-400 ℃.

In the invention, the mass ratio of the first water addition amount to the raw materials is preferably 0.5: 1-2: 1.

In the invention, the mass ratio of the first water adding amount to the raw materials is preferably 1: 1-2: 1.

In the present invention, the amount of the second water addition is preferably 50 to 100% by weight of the heavy oil feedstock.

In the present invention, it is preferable that each stage of the reaction is carried out under supercritical hydrothermal conditions.

In the present invention, oil sand bitumen refers to petroleum bitumen or natural bitumen.

In the present invention, the discharged vapor is vaporizedThe light oil product in the component is generally C₄～C₂₅The alkane and the polycyclic aromatic hydrocarbon of (a),

in the present invention, the light oil product discharged from the first reaction is preferably 60 to 80% by weight of the heavy oil feedstock.

The method of the invention does not need a catalyst, can improve the viscosity reduction rate of the oil sand asphalt and inhibit or avoid the coking phenomenon of the system.

Drawings

FIG. 1 is a schematic diagram of a hydrothermal visbreaking cyclone reactor for poor-quality heavy oil.

The specific steps are described below with reference to the accompanying drawings: the reaction raw material and fresh water are respectively passed through heat exchanger 7 and 8 to make heat exchange with water released from outlet valve 18 of reactor 1 and light weight produced by reaction, then fed into reactor, heated to target temperature and retained for a certain time, the outlet valve of reactor is opened, the light oil and water produced in the reaction can be escaped from reaction system by means of pressure, and respectively preheated with raw material and fresh water, fed into gas-liquid separator 15, the condensed liquid product can be fed into liquid collecting tank 16, the non-condensable gas can be fed into gas collecting tank 17, when the reaction is primary reaction, the separated water can be directly discharged out of the system, when the reaction is secondary reaction, the separated water and supplemented fresh water can be mixed, and fed back into the reactor by means of circulating pump 9, heated to target temperature, and continuously undergone secondary reaction with material in the reactor, and the material and water after the reaction can be discharged out of reaction system through outlet valve 18, and (3) repeating the material collection step, discharging water separated by the gas-liquid separator out of the system, repeating the steps again when the reaction is a 3-stage reaction until the property of the reaction product reaches the expected target, and finally finishing the reaction.

Wherein:

1-rotary tubular reactor, 2-casing (heating furnace), 3-stirring frame, 4-filling tube, 5-temperature thermocouple, 6-pressure gauge, 7, 8-heat exchange unit, 9-circulating water pump, 10-explosion-proof valve, 11-motor conveyor belt chain, 12-motor and speed changer, 13-bearing support, 14-temperature control instrument, 15-gas-liquid separator, 16-liquid product storage tank, 17-gas product storage tank, 18-outlet valve

Detailed Description

The following examples illustrate the invention in detail: the present example is carried out on the premise of the technical scheme of the present invention, and detailed embodiments and processes are given, but the scope of the present invention is not limited to the following examples, and the experimental methods without specific conditions noted in the following examples are generally performed according to conventional conditions.

The invention is further illustrated by the following examples, which are intended to better understand the content of the invention and not to limit the scope of protection of the invention. In order to highlight the benefits of the secondary and multistage reactions, comparisons were made with the primary reaction in terms of product viscosity, liquid yield, light oil yield, and coke rate, respectively.