Microchannel reaction system and residue oxidation reaction system

Abstract

The utility model relates to micro -channel reaction field discloses a kind of micro -channel reaction system and residual oil oxidation reaction system.The micro -channel reaction system includes: micro -mixing unit, micro -channel reaction unit and product collection unit connected in turn;Micro -channel reaction unit includes at least one group of reaction components, each group of reaction components independently includes at least one coil reactor and at least one secondary mixing module, and coil reactor is connected in series with secondary mixing module by pipeline;Wherein, the feed inlet of coil reactor is communicated with micro -mixing unit, for the reaction of mixed reaction raw materials;Secondary mixing module includes first micro -mixer and second micro -mixer, and first micro -mixer and second micro -mixer are connected by pipeline to form annular channel, for the shunt and merging of mixed material;Micro -channel reaction system has the characteristics of high mass transfer efficiency, short reaction time, high reaction conversion rate, controllable and high safety.

Description

Technical Field

[0001] This utility model relates to the field of microchannel reaction, specifically to a microchannel reaction system and a residue oil oxidation reaction system. Background Technology

[0002] With the increasing trend of heavier and lower-quality crude oil, refineries will generate large quantities of difficult-to-process high-sulfur residue oil. The sulfur compounds in this residue oil are mainly polyaromatic thiophene compounds. These sulfides not only cause corrosion of reaction equipment and catalyst poisoning and deactivation, but also degrade the quality of processed oil products, failing to meet environmental regulations for clean oil products. Furthermore, for delayed coking processes, high-sulfur residue oil feedstock will directly lead to excessive sulfur content (>3%) in the produced petroleum coke, failing to meet factory standards and causing significant economic losses to enterprises.

[0003] Hydrotreating is currently the most important desulfurization technology for residual oil, but it requires high-temperature and high-pressure reaction conditions, resulting in high hydrogen consumption and large equipment investment. Furthermore, due to steric hindrance, hydrotreating is difficult to effectively remove polyaromatic thiophene compounds from residual oil. Oxidative desulfurization (OCS), on the other hand, has milder reaction conditions and lower cost. It can convert polyaromatic thiophene compounds in residual oil into more polar sulfoxides and sulfones for removal, offering high reaction efficiency and a simple process, thus showing promising industrial application prospects. However, residual oil oxidative desulfurization using H₂O₂ as the oxidant is a heterogeneous reaction process, facing mass transfer problems between the oil and water phases, as well as the decomposition of the oxidant.

[0004] The residual oil oxidation reaction equipment disclosed in patent CN213652386U adopts an intermittent reaction mode, and indirectly achieves continuous reaction operation by connecting multiple reaction devices in parallel. The safety of the reaction process is ensured by controlling the amount of oxidant added, but its reaction time is long and fails to effectively enhance the mass transfer process.

[0005] Therefore, there is an urgent need to develop an intrinsically safe continuous reaction system for residue oil oxidation that can effectively enhance two-phase mass transfer. Utility Model Content

[0006] The purpose of this invention is to overcome the problems of low mass transfer efficiency, long reaction time, low reaction conversion rate, uncontrollability, and poor safety in the existing technology, and to provide a microchannel reaction system and a residue oil oxidation reaction system. This microchannel reaction system has the characteristics of high mass transfer efficiency, short reaction time, high reaction conversion rate, controllability, and high safety.

[0007] To achieve the above objectives, the first aspect of this utility model provides a microchannel reaction system, the microchannel reaction system comprising: a micromixing unit 2, a microchannel reaction unit 3, and a product collection unit 5 connected in sequence;

[0008] The micro-mixing unit 2 includes at least two reactant inlets and a mixture outlet for mixing at least two reactants;

[0009] The microchannel reaction unit 3 includes at least one set of reaction components, each set of reaction components independently including at least one coil reactor 301 and at least one secondary mixing module 302, the coil reactor 301 and the secondary mixing module 302 are connected in series through pipelines;

[0010] The feed inlet of the coil reactor 301 is connected to the micro-mixing unit 2, which is used to react the mixed reaction raw materials.

[0011] The secondary mixing module 302 includes a first micro mixer b and a second micro mixer c. The first micro mixer b and the second micro mixer c are connected by pipelines to form an annular channel for splitting and merging the mixed materials.

[0012] The product collection unit 5 is connected to the outlet of the secondary mixing module 302 and is used to collect the reaction products.

[0013] Optionally, the micro-mixing unit 2 includes a micro-mixer a, which is selected from at least one of T-type, Y-type and coaxial micro-mixers, and the inner diameter of the channel in the micro-mixer a is 0.1-1 mm.

[0014] Optionally, each reaction assembly includes a coil reactor and two or more secondary mixing modules 302, wherein the two or more secondary mixing modules 302 are connected in parallel.

[0015] Optionally, the microchannel reaction unit 3 includes at least two sets of reaction components, which are connected in series.

[0016] Optionally, the inner diameter of the coil reactor 301 is 0.1-1 mm and the length is 2-8 m.

[0017] Optionally, the first micro-mixer b and the second micro-mixer c are each independently selected from at least one of T-type and Y-type micro-mixers, and the inner diameter of the channel in the first micro-mixer b and the second micro-mixer c is each independently 0.1-1 mm.

[0018] Optionally, the inner diameter of the connecting line between the first micro mixer b and the second micro mixer c is 0.1-1 mm.

[0019] Optionally, the system further includes a constant temperature control system 4 for controlling the temperature of the micro-mixing unit 2 and the microchannel reaction unit 3.

[0020] Optionally, the product collection unit 5 includes a gravity settling tank and / or a centrifuge.

[0021] The second aspect of this utility model provides a residue oil oxidation reaction system, which includes the microchannel reaction system described in the first aspect above, and a liquid phase feeding unit 1;

[0022] The liquid phase feeding unit 1 includes a first raw material tank 101 and a second raw material tank 102;

[0023] The micro-mixing unit 2 includes a first inlet and a second inlet. The first raw material tank 101 and the first inlet of the micro-mixing unit 2 are connected in series via pipelines to supply residual oil to the micro-mixing unit 2.

[0024] The second raw material tank 102 and the second feed inlet of the micro-mixing unit 2 are connected in series via pipelines to provide oxidant and water-soluble catalyst to the micro-mixing unit 2.

[0025] The above technical solution achieves microscale mixing between reactants, and the resulting micron-sized droplets increase the mass transfer coefficient and mass transfer area between the two phases. The secondary mixing module further promotes the collision, breakup, and surface renewal of the microdroplets, significantly improving the mass transfer rate, effectively shortening the reaction time, and increasing the reaction conversion rate (>50%). The entire reaction process is simple, continuous, controllable, and highly safe, enabling continuous processing of reactants.

[0026] The microchannel reaction system provided by this invention is suitable for the oxidative desulfurization reaction of residual oil and the separation of its products. It can realize continuous processing of residual oil oxidation, improve the mass transfer coefficient and mass transfer area, and increase the reaction conversion rate to a high level (>50%). Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the microreactor system structure for residue oil oxidation reaction provided by this utility model.

[0028] Explanation of reference numerals in the attached figures

[0029] Detailed Implementation

[0030] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0031] In this invention, unless otherwise stated, directional terms such as "up," "down," "left," and "right" generally refer to the orientation shown in the accompanying drawings. "Inner" and "outer" refer to the inner and outer sides relative to the outline of each component itself.

[0032] In this invention, unless otherwise stated, the atmospheric pressure is one standard atmosphere.

[0033] The first aspect of this utility model provides a microchannel reaction system, the microchannel reaction system comprising: a micromixing unit 2, a microchannel reaction unit 3, and a product collection unit 5 connected in sequence;

[0034] The micro-mixing unit 2 includes at least two reactant inlets and a mixture outlet for mixing at least two reactants;

[0035] The microchannel reaction unit 3 includes at least one set of reaction components, each set of reaction components independently including at least one coil reactor 301 and at least one secondary mixing module 302, the coil reactor 301 and the secondary mixing module 302 are connected in series through pipelines;

[0036] The feed inlet of the coil reactor 301 is connected to the micro-mixing unit 2, which is used to react the mixed reaction raw materials.

[0037] The secondary mixing module 302 includes a first micro mixer b and a second micro mixer c. The first micro mixer b and the second micro mixer c are connected by pipelines to form an annular channel for splitting and merging the mixed materials.

[0038] The product collection unit 5 is connected to the outlet of the secondary mixing module 302 and is used to collect the reaction products.

[0039] The microchannel reaction system provided by this invention features a simple, continuous, and controllable process with high safety, enabling continuous processing of reaction materials. A micro-mixer facilitates microscale mixing between the two phases of the reaction materials, forming micron-sized droplets that increase the mass transfer coefficient and area between the two phases. A secondary mixing module further promotes the collision, breakup, and surface renewal of the microdroplets, significantly improving the mass transfer rate and achieving efficient catalyst transfer between the two phases. This effectively shortens the reaction time and increases the reaction conversion rate to >50%.

[0040] In this utility model, "the first micro-mixer b and the second micro-mixer c are connected by a pipeline to form an annular channel" means that the first micro-mixer and the second micro-mixer form a closed loop, and the outlet of the first micro-mixer and the inlet of the second micro-mixer are connected by a pipeline. Figure 1 As shown.

[0041] According to a preferred embodiment of the present invention, the micro-mixing unit 2 includes a micro-mixer a, which is selected from at least one of T-type, Y-type, and coaxial micro-mixers, more preferably T-type. The inner diameter of the channel in the micro-mixer a is 0.1-1 mm, more preferably 0.3-0.5 mm. This is more conducive to improving the reaction conversion rate.

[0042] According to a preferred embodiment of this invention, each reaction assembly includes a coil reactor and two or more secondary mixing modules 302, wherein the two or more secondary mixing modules 302 are connected in parallel. This is more conducive to improving mass and heat transfer efficiency, shortening reaction time, and increasing reaction conversion rate.

[0043] This invention offers a wide range of options for the number of reaction components in the microchannel reaction unit. Those skilled in the art can set the number of components according to actual needs. Preferably, the microchannel reaction unit 3 includes at least two sets of reaction components. Connecting two or more sets of reaction components in series is more conducive to extending the reaction residence time. Increasing the number of reaction channels can quickly achieve process scale-up.

[0044] This invention offers a wide range of options for the length of the coil reactor. Preferably, the inner diameter of the coil reactor 301 is 0.1-1 mm, more preferably 0.3-0.5 mm, and the length is 2-8 m, more preferably 3-6 m. This is more conducive to improving the reaction conversion rate.

[0045] According to a preferred embodiment of the present invention, the first micromixer b and the second micromixer c are each independently selected from at least one of T-type and Y-type micromixers, more preferably T-type. This separation and merging of the mixture promotes droplet collision and breakup, surface renewal, and is more conducive to improving mass and heat transfer efficiency, shortening reaction time, and increasing reaction conversion rate.

[0046] According to a preferred embodiment of this invention, the inner diameter of the channels in the first micromixer b and the second micromixer c is independently 0.1-1 mm, more preferably 0.3-0.5 mm. This is more conducive to promoting the collision and breakup of microdroplets and surface renewal, improving the mass transfer rate, shortening the reaction time, and increasing the reaction conversion rate. A large inner diameter results in large, dispersed droplets with a small specific surface area, leading to poor mass transfer. A small inner diameter results in a large pressure drop, high power consumption, and a tendency to form rigid spheres that cannot be broken, thus affecting mass and heat transfer.

[0047] According to a preferred embodiment of this invention, the inner diameter of the connecting pipeline between the first micromixer b and the second micromixer c is 0.1-1 mm, more preferably 0.3-0.5 mm. This is more conducive to improving the reaction conversion rate.

[0048] According to a preferred embodiment of the present invention, the system further includes a constant temperature control system 4 for controlling the temperature of the micro-mixing unit 2 and the microchannel reaction unit 3.

[0049] The constant temperature control system 4 includes a constant temperature water bath and / or a constant temperature oil bath system.

[0050] According to a preferred embodiment of the present invention, the product collection unit 5 includes a gravity settling tank and / or a centrifuge for collecting and separating oxidation products.

[0051] The second aspect of this utility model provides a residue oil oxidation reaction system, which includes the microchannel reaction system described in the first aspect above, and a liquid phase feeding unit 1;

[0052] The liquid phase feeding unit 1 includes a first raw material tank 101 and a second raw material tank 102;

[0053] The micro-mixing unit 2 includes a first inlet and a second inlet. The first raw material tank 101 and the first inlet of the micro-mixing unit 2 are connected in series via pipelines to supply residual oil to the micro-mixing unit 2.

[0054] The second raw material tank 102 and the second feed inlet of the micro-mixing unit 2 are connected in series via pipelines to provide oxidant and water-soluble catalyst to the micro-mixing unit 2.

[0055] The microchannel reaction system provided by this invention is suitable for the oxidative desulfurization reaction of residual oil and the separation of its products. It can realize continuous processing of residual oil oxidation, improve the mass transfer coefficient and mass transfer area, and increase the reaction conversion rate to a high level (>50%).

[0056] According to a preferred embodiment of the present invention, a solvent is used to dilute the residual oil. Preferably, the solvent is at least one of toluene, gasoline distillate oil, and diesel distillate oil.

[0057] The present invention allows for a wide range of choices of the oxidant. Preferably, the oxidant is selected from at least one of hydrogen peroxide, peroxyformic acid, peracetic acid, peroxypropionic acid, and concentrated nitric acid.

[0058] This invention allows for a wide range of water-soluble catalysts, which can be selected by those skilled in the art according to actual needs. Preferably, the water-soluble catalyst is at least one of peroxymolybdic acid, peroxymolybdate, peroxytungstic acid, and peroxytungstate.

[0059] According to some specific embodiments of this utility model, such as Figure 1As shown, the above-described reaction system is used for the oxidation reaction of residual oil. The liquid-phase feed unit 1, micro-mixing unit 2, microchannel reaction unit 3, and product collection unit 5 are connected in series for the oxidation reaction. A constant temperature control system 4 controls the temperature of the residual oil oxidation reaction in the micro-mixing unit 2 and microchannel reaction unit 3. Solvent-diluted residual oil is pumped to the first inlet of the micro-mixing unit via the first feed pump 102. The oxidant and water-soluble catalyst are pumped to the second inlet of the micro-mixing unit via the second feed pump 104. The solvent-diluted residual oil, oxidant, and water-soluble catalyst form a mixture, which is then pumped to the coil reactor 301 through the outlet of the micro-mixing unit 2. From the coil reactor, the mixture is pumped to the secondary mixing module 302, which splits and merges the mixture, promoting droplet collision and surface renewal. The stream from the secondary mixing module 302 is then pumped to the product collection unit 5 through the outlet of the secondary mixing module 302. The residual oil oxidation products are separated and collected by a gravity settling tank or centrifuge.

[0060] The present invention will be described in detail below through embodiments.

[0061] In the following examples and comparative examples, the residue feedstock is vacuum residue from Fujian Refining & Chemical Plant of China Petroleum & Chemical Corporation.

[0062] In the following examples and comparative examples, energy dispersive X-ray fluorescence spectrometry (GB17040) was used to analyze the sulfur content in diluted residue feedstock.

[0063] In the following examples and comparative examples, Fourier transform infrared spectroscopy (FTIR) with attenuated total reflectance accessory (ATR) was used to quantitatively analyze sulfone sulfur in the oxidation products of residual oil, and the content of oxidized sulfur in the oxidized residual oil was calculated.

[0064] In the following examples and comparative examples, the oxidation conversion rate of the residue oil is calculated using the following formula: Conversion rate = Sulfone sulfur content in oxidized residue oil / Sulfur content in diluted residue oil × 100%.

[0065] Example 1

[0066] The residual oil was preheated to a fluid state, and toluene was added at a mass ratio of 1:1 to the residual oil. The mixture was then stirred to obtain diluted residual oil, which had a sulfur content of 2.71%. This diluted residual oil feedstock was placed in the first feedstock tank 101. An aqueous solution of H2O2 (based on the total mass of the aqueous solution, with an H2O2 content of 30 wt%) was placed in the second feedstock tank 103 as an oxidant. Then, 10 wt% of a water-soluble catalyst, peroxymolybdic acid (measured based on the mass of the oxidant), was added and mixed thoroughly. Figure 1A micro-reaction system was used to conduct oxidative desulfurization experiments on residual oil feedstock. In the micro-mixing unit, micro-mixer a was a T-type micro-mixer with an inner diameter of 0.45 mm. The microchannel reaction unit consisted of two sets of reaction components connected in series via pipelines. Each set of reaction components consisted of a coil reactor and a secondary mixing module connected in series via pipelines. The coil reactor had an inner diameter of 0.5 mm and a length of 3 m. In the secondary mixing module, both the first micro-mixer b and the second micro-mixer c were Y-type micro-mixers with an inner diameter of 0.5 mm. The connecting pipeline between the first and second micro-mixers b and c had an inner diameter of 0.5 mm. A constant temperature control system was used, with the water bath temperature set at 85℃. The feed rate of residual oil feedstock was 1.38 mL / min, and the feed rates of hydrogen peroxide and catalyst were 0.35 mL / min. The reaction products were processed using a centrifuge to obtain oxidized residual oil. ATR-FTIR spectroscopy analysis showed that the sulfone sulfur content in the oxidized residual oil was 1.59%, indicating an oxidation conversion rate of 58.6%.

[0067] Example 2

[0068] The method is the same as in Example 1, except that the T-type micromixer used in the micromixing unit is replaced with a Y-type micromixer with an inner diameter of 0.5 mm. ATR-FTIR spectroscopy analysis showed that the sulfone sulfur content in the oxidized residue was 1.53%, indicating an oxidation conversion rate of 56.5%.

[0069] Example 3

[0070] The method is the same as in Example 1, except that the microchannel reaction unit has only one set of reaction components, consisting of a coil reactor and a secondary mixing module connected in series via pipelines, with the coil length being 6m. ATR-FTIR spectroscopy analysis showed that the sulfone sulfur content in the oxidized residue was 1.50%, indicating an oxidation conversion rate of 55.5%.

[0071] Example 4

[0072] Following the method of Example 1, the difference lies in that the micro-mixer a in the micro-mixing unit uses a T-type mixer with an inner diameter of 0.3 mm, the coil in the micro-reaction unit has an inner diameter of 0.3 mm, and both the first micro-mixer b and the second micro-mixer c in the secondary mixing module use Y-type micro-mixers with an inner diameter of 0.3 mm. The inner diameter of the connecting pipeline between the first and second micro-mixers b and c is 0.3 mm. Analysis by ATR-FTIR spectroscopy showed that the sulfone sulfur content in the oxidized residue oil was 1.61%, indicating an oxidation conversion rate of 59.4%.

[0073] Example 5

[0074] The method follows the same procedure as in Example 1, except that the micro-mixer a in the micro-mixing unit uses a T-type mixer with an inner diameter of 0.8 mm, the coil in the micro-reaction unit has an inner diameter of 0.8 mm, and both the first micro-mixer b and the second micro-mixer c in the secondary mixing module use Y-type micro-mixers with an inner diameter of 0.8 mm. The connecting pipeline between the first and second micro-mixers b and c has an inner diameter of 0.8 mm. Analysis using ATR-FTIR spectroscopy shows that the sulfone sulfur content in the oxidized residue is 1.51%, indicating an oxidation conversion rate of 55.7%.

[0075] Comparative Example 1

[0076] The residual oil was preheated to a fluid state and mixed with toluene at a mass ratio of 1:1 to obtain diluted residual oil. Its sulfur content was analyzed to be 2.71%. 50g of the diluted residual oil feedstock was placed in a three-necked flask (with a magnetic stirrer). 15g of a 30% (w / w) H₂O₂ aqueous solution was used as the oxidant, and 10% (w / w) of a water-soluble catalyst, peroxymolybdic acid, was added to the oxidant and mixed thoroughly. The oxidant and catalyst were added dropwise to the flask at a rate of 0.25g / min, the reaction time was 60min, and the reaction temperature was set at 85℃ under normal pressure. ATR-FTIR spectroscopy analysis showed that the sulfone sulfur content in the oxidized residual oil was 1.24%, indicating an oxidation conversion rate of 45.7%.

[0077] Comparative Example 2

[0078] The method is the same as in Example 1, except that the microreactor unit contains only one coil reactor, without a secondary mixing module, and the coil length is 6m. ATR-FTIR spectroscopy analysis showed that the sulfone sulfur content in the oxidized residue was 1.36%, indicating an oxidation conversion rate of 50.2%.

[0079] The results from the examples and comparative examples show that the comparative examples, by using intermittent feeding or not using a secondary mixing module, reduce the reaction efficiency, and the sulfone sulfur content in the oxidized residue and the oxidation conversion rate of the residue will be significantly reduced. The examples using the micro-reaction system provided by this invention have a significantly better oxidation conversion rate.

[0080] The preferred embodiments of this utility model have been described in detail above; however, this utility model is not limited thereto. Within the scope of the technical concept of this utility model, various simple modifications can be made to the technical solution of this utility model, including combining the various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed by this utility model and are all within the protection scope of this utility model.

Claims

1. A microchannel reaction system, characterized in that, The microchannel reaction system includes: a micromixing unit (2), a microchannel reaction unit (3), and a product collection unit (5) connected in sequence. The micro-mixing unit (2) includes at least two reactant inlets and a mixture outlet for mixing at least two reactants; The microchannel reaction unit (3) includes at least one set of reaction components, each set of reaction components independently including at least one coil reactor (301) and at least one secondary mixing module (302), the coil reactor (301) and the secondary mixing module (302) being connected in series via pipelines; The feed inlet of the coil reactor (301) is connected to the micro-mixing unit (2) for reacting the mixed reaction raw materials; The secondary mixing module (302) includes a first micro mixer (b) and a second micro mixer (c), which are connected by pipelines to form an annular channel for diverting and merging the mixed materials; The product collection unit (5) is connected to the outlet of the secondary mixing module (302) for collecting reaction products.

2. The microchannel reaction system according to claim 1, characterized in that, The micro-mixing unit (2) includes a micro-mixer (a), which is selected from at least one of T-type, Y-type and coaxial micro-mixers, and the inner diameter of the channel in the micro-mixer (a) is 0.1-1 mm.

3. The microchannel reaction system according to claim 1, characterized in that, Each reaction assembly includes a coil reactor and two or more secondary mixing modules (302), wherein the two or more secondary mixing modules (302) are connected in parallel.

4. The microchannel reaction system according to claim 1, characterized in that, The microchannel reaction unit (3) includes at least two sets of reaction components, which are connected in series.

5. The microchannel reaction system according to claim 1, characterized in that, The inner diameter of the coil reactor (301) is 0.1-1 mm and the length is 2-8 m.

6. The microchannel reaction system according to claim 1, characterized in that, The first micro mixer (b) and the second micro mixer (c) are each independently selected from at least one of T-type and Y-type micro mixers, and the inner diameter of the channel in the first micro mixer (b) and the second micro mixer (c) is independently 0.1-1 mm.

7. The microchannel reaction system according to claim 1, characterized in that, The inner diameter of the connecting line between the first micro mixer (b) and the second micro mixer (c) is 0.1-1 mm.

8. The microchannel reaction system according to claim 1, characterized in that, The system also includes a constant temperature control system (4) for controlling the temperature of the micro-mixing unit (2) and the microchannel reaction unit (3).

9. The microchannel reaction system according to claim 1, characterized in that, The product collection unit (5) includes a gravity settling tank and / or a centrifuge.

10. A residue oil oxidation reaction system, characterized in that, The residue oil oxidation reaction system includes the microchannel reaction system according to any one of claims 1-9, and a liquid phase feed unit (1). The liquid phase feeding unit (1) includes a first raw material tank (101) and a second raw material tank (102); The micro-mixing unit (2) includes a first feed inlet and a second feed inlet. The first raw material tank (101) and the first feed inlet of the micro-mixing unit (2) are connected in series through pipelines to supply residual oil to the micro-mixing unit (2). The second raw material tank (102) and the second feed inlet of the micro-mixing unit (2) are connected in series via pipelines to provide oxidant and water-soluble catalyst to the micro-mixing unit (2).

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