Catalytic gasoline hydrogenation method and device for producing chemical raw materials
By improving the process flow and structure of the catalytic gasoline hydrogenation unit, catalytic gasoline is separated into light, medium, and heavy gasoline components, which are then subjected to hydrogenation and stripping processes. This solves the problem of catalytic gasoline failing to be converted into chemical raw materials, enabling the production of chemical raw materials and increasing refinery profits.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-30
- Publication Date
- 2026-03-10
AI Technical Summary
The failure of catalytic gasoline to be effectively converted into chemical raw materials led to a decline in gasoline sales after the popularization of new energy vehicles, which squeezed the profit margins of refineries.
By improving the process flow and structure of the catalytic gasoline hydrogenation unit, the full-fraction stable gasoline is pre-hydrogenated and then separated into light, medium and heavy gasoline components. Under specific conditions, these components are then hydrogenated and stripped to be converted into chemical products such as ethylene feedstock, aromatics feedstock and liquefied petroleum gas.
This technology enables the complete conversion of catalytic gasoline into chemical raw materials, solving the problem of declining gasoline sales and increasing refinery profit margins.
Smart Images
Figure CN121628675A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the technical field of petrochemical industry, and particularly relates to a catalytic gasoline hydrogenation method and device for producing chemical raw materials. BACKGROUND
[0002] The original design raw material of the catalytic gasoline hydrogenation device is catalytic cracking device stable gasoline. After full-range stable gasoline is pre-hydrogenated, the light gasoline at the top of the fractionating tower is sent to the etherization device to react with methanol to form 92# national VI gasoline. The heavy gasoline at the bottom of the fractionating tower is selectively removed of sulfur by the hydrogenation desulfurization unit and also serves as a gasoline blending component. The products of the device are all gasoline blending components. Under the background of the rise of new energy vehicles, the large production of gasoline compresses the profit space of the refinery, and a technical solution is urgently needed to convert the catalytic gasoline into chemical raw materials to cope with the problem of the decline in gasoline sales. SUMMARY
[0003] The application aims to cope with the influence of new energy vehicles on gasoline sales, and realizes the purpose of converting all catalytic gasoline into chemical raw materials by improving the process flow and device.
[0004] In order to achieve the above-mentioned purpose, the application is realized by the following technical scheme:
[0005] The catalytic gasoline hydrogenation method for producing chemical raw materials comprises the following steps:
[0006] Step 1: Pre-hydrogenation reaction of full-range stable gasoline is carried out under the conditions of a pressure of 2.3 MPa and a temperature of 120-130 DEG C, so that the diene content of the light gasoline product after reaction is reduced to within 200 ppm, and the sulfur content is within 15 ppm;
[0007] Step 2: The material after pre-hydrogenation reaction is sent to a fractionating tower for separation of light, medium and heavy components, the tower pressure is controlled at 0.68 MPa, the tower bottom temperature is controlled at 289 DEG C, the light gasoline and medium gasoline extraction amount are adjusted, so that the light gasoline end boiling point is <70 DEG C, the medium gasoline D86 distillation range is 75-175 DEG C, and the heavy gasoline initial boiling point is >155 DEG C;
[0008] Step 3: The light gasoline is mixed with the circulating oil at a mass ratio of 2:1, and then pressurized to 2.6 MPa by a feeding pump and mixed with circulating hydrogen, and then heated to 170 DEG C by a feeding heater and then enters the light gasoline hydrogenation reactor, so that full olefin saturation reaction occurs under the conditions of a reaction pressure of 2.3 MPa, a circulating hydrogen flow of 110000 Nm 3 / h, a circulating flow of 60 t / h, and a reactor outlet temperature of 262.5 DEG C;
[0009] Step 4: The light gasoline reaction products are subjected to gas-liquid separation in a high-precision tank. The separated recycled hydrogen is pressurized to 2.6 MPa by a recycled hydrogen compressor and then mixed with fresh hydrogen before being transported to various hydrogen mixing points.
[0010] Step 5: Hydrogenated light gasoline containing dissolved hydrogen from the high-precision tank is fed into the stabilizer. The stabilizer pressure is controlled at 0.7 MPa, the bottom temperature at 112°C, and the reflux ratio at 10.8 (mass fraction) for heat stripping, so that the hydrogen content of the hydrogenated light gasoline at the bottom of the tower is <0.001% and the olefin content is <1% (mass fraction). Part of the hydrogenated light gasoline at the bottom of the tower is recycled to the feed section, and the other part is sent as qualified product to the ethylene unit as cracking feedstock.
[0011] Step 6: Extract the intermediate gasoline from the middle of the fractionation tower and send it to the naphtha hydrotreating unit for blending and use as reforming feedstock to produce aromatic products.
[0012] Step 7: Extract heavy gasoline from the bottom of the fractionation tower and send it to the diesel hydrocracking unit for blending to produce liquefied petroleum gas and heavy naphtha.
[0013] Preferably, the full-fraction stabilized gasoline in step 1 is stabilized gasoline from a catalytic cracking unit.
[0014] Preferably, the temperature rise during the full olefin saturation reaction in the light gasoline hydrogenation reactor described in step 3 is 92.5°C.
[0015] Preferably, the molar fraction of hydrogen in the hydrogenated light gasoline in step 5 is 1.45%.
[0016] This invention discloses a catalytic gasoline hydrogenation apparatus for producing chemical raw materials, comprising:
[0017] A pre-hydrogenation reactor is used for pre-hydrogenation of full-fraction stabilized gasoline. A fractionating tower, connected to the outlet pipeline of the pre-hydrogenation reactor, is used to separate light gasoline, medium gasoline, and heavy gasoline. The fractionating tower has a medium gasoline extraction pipeline in the middle and a heavy gasoline extraction pipeline at the bottom. A light gasoline hydrogenation unit includes a feed pump, a feed heater, a light gasoline hydrogenation reactor, and a high-precision tank. The feed end of the light gasoline hydrogenation reactor is connected to the light gasoline extraction pipeline, circulating oil pipeline, and circulating hydrogen pipeline of the fractionating tower via pipelines. The feed pump is located on the mixing pipeline of light gasoline and circulating oil, and the feed heater is located on the mixing pipeline of the mixture and circulating hydrogen. The high-precision separator is connected to the discharge pipeline of the light gasoline hydrotreating reactor for gas-liquid separation; the circulating hydrogen compressor is connected to the gas phase discharge pipeline of the high-precision separator for pressurizing the circulating hydrogen, mixing it with fresh hydrogen, and delivering it to each hydrogen mixing point; the stabilizer is connected to the liquid phase discharge pipeline of the high-precision separator for heating and stripping the hydrotreated light gasoline, and the bottom of the stabilizer is equipped with a circulation pipeline and a product output pipeline; the naphtha hydrotreating unit connection pipeline is connected to the middle gasoline extraction pipeline of the fractionation tower for sending the middle gasoline to the naphtha hydrotreating unit; the diesel hydrocracking unit connection pipeline is connected to the heavy gasoline extraction pipeline of the fractionation tower for sending the heavy gasoline to the diesel hydrocracking unit.
[0018] Preferably, it also includes a feed tank, which is connected to the feed end of the pre-hydrogenation reactor via a feed pump, for storing catalytic gasoline.
[0019] Preferably, the top of the fractionation tower is provided with a light gasoline extraction pipeline and connected to a reflux tank for the treatment of non-condensable gas after the light gasoline separation.
[0020] Preferably, the top of the stabilization tower is connected to a reflux tank for the treatment of non-condensable gases in the stabilization tower.
[0021] Preferably, the light gasoline hydrogenation reactor is a fixed-bed reactor filled with a hydrogenation catalyst.
[0022] Preferably, the outlet pressure of the circulating hydrogen compressor is 2.6 MPa.
[0023] Beneficial effects: This invention requires only minimal modifications to existing catalytic gasoline hydrogenation units to change their function, reducing the difficulty and cost of modification; after applying this invention, catalytic gasoline can be completely converted into ethylene and aromatic feedstocks, completely solving the problem of declining gasoline sales after the popularization of new energy vehicles and increasing refinery profit margins; this invention has application and reference value for similar units and has broad promotional value. Attached Figure Description
[0024] Figure 1 This is a block diagram illustrating the principle of the present invention.
[0025] Figure 2 This is a simulation diagram of the present invention. Detailed Implementation
[0026] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0027] This invention provides a method and apparatus for catalytic gasoline hydrogenation to produce chemical raw materials. By improving the process flow and structure of existing catalytic gasoline hydrogenation apparatus, it realizes the conversion of all catalytic gasoline into chemical raw materials such as ethylene and aromatics, thus solving the problem of declining gasoline sales caused by the popularization of new energy vehicles.
[0028] The specific embodiments of the present invention will be described in detail below with reference to the process steps and device structure.
[0029] Process steps: Full-range stabilized gasoline (from catalytic cracking unit stabilized gasoline) undergoes pre-hydrogenation reaction at a pressure of 2.3 MPa and a temperature of 120-130℃, which reduces the diene content of the light gasoline product after the reaction to less than 200 ppm and the sulfur content to less than 15 ppm, effectively removing impurities from the feedstock and providing qualified materials for subsequent separation and reaction.
[0030] The material after the pre-hydrogenation reaction is fed into a fractionation tower for separating light, medium and heavy components. The tower pressure is controlled at 0.68 MPa and the bottom temperature at 289℃. By adjusting the extraction rates of light and medium gasoline, the final boiling point of light gasoline is kept below 70℃, the boiling range of medium gasoline D86 is 75-175℃, and the initial boiling point of heavy gasoline is kept above 155℃, thus achieving effective separation of light, medium and heavy gasoline.
[0031] Light gasoline and circulating oil are mixed at a mass ratio of 2:1, then pressurized to 2.6 MPa by a feed pump and mixed with circulating hydrogen. The mixture is then heated to 170°C by a feed heater before entering the light gasoline hydrogenation reactor, where it reacts at a pressure of 2.3 MPa and a circulating hydrogen flow rate of 110,000 Nm³. 3 Under conditions of 60 t / h and a circulating flow rate of 60 t / h, a full olefin saturation reaction occurs, with a reactor outlet temperature of 262.5℃ and a temperature rise of 92.5℃, ensuring complete olefin saturation in the light gasoline. The simulation results are as follows: Figure 2 :
[0032] The light gasoline reaction products undergo gas-liquid separation in a high-pressure separator. The separated recycled hydrogen is pressurized to 2.6 MPa by a recycled hydrogen compressor and then mixed with fresh hydrogen before being transported to various hydrogen mixing points to achieve the recycling of recycled hydrogen.
[0033] Hydrogenated light gasoline containing dissolved hydrogen (1.45% molar fraction) from the high-precision tank is fed into the stabilizer. The stabilizer pressure is controlled at 0.7 MPa, the bottom temperature at 112°C, and the reflux ratio at 10.8 (mass fraction) for heat stripping, so that the hydrogen content of the hydrogenated light gasoline at the bottom of the tower is <0.001% and the olefin content is <1% (mass fraction), which meets the feedstock quality requirements of the ethylene unit and the storage requirements of the tank area. Part of the hydrogenated light gasoline at the bottom of the tower is recycled to the feedstock section, and the other part is sent to the ethylene unit as cracking feedstock as qualified product.
[0034] Medium gasoline (D86 boiling range 75-175℃, basically free of C12 and with low C11 content) is extracted from the middle of the fractionation tower and sent to the naphtha hydrocracking unit for blending as a reforming feedstock to produce aromatic products, without affecting the regeneration rate of the reforming catalyst; heavy gasoline (initial boiling point >155℃, meeting the boiling range requirements of the diesel cracking unit) is extracted from the bottom of the fractionation tower and sent to the diesel hydrocracking unit for blending to produce liquefied petroleum gas and heavy naphtha.
[0035] Device structure:
[0036] The apparatus of the present invention includes a feed tank, a pre-hydrogenation reactor, a fractionation tower, a light gasoline hydrogenation unit (feed pump, feed heater, light gasoline hydrogenation reactor, high-precision tank), a circulating hydrogen compressor, a stabilizer tower, connecting pipelines for a naphtha hydrogenation unit, and connecting pipelines for a diesel hydrocracking unit. The feed tank is connected to the feed end of the pre-hydrogenation reactor via a feed pump and is used to store catalytic gasoline. The pre-hydrogenation reactor is used for the pre-hydrogenation reaction of full-range stabilized gasoline. The fractionation tower is connected to the discharge pipeline of the pre-hydrogenation reactor. It has a light gasoline extraction pipeline at the top (connected to a reflux tank and related pipelines for handling non-condensable gases), a medium gasoline extraction pipeline in the middle, and a heavy gasoline extraction pipeline at the bottom, used to separate light, medium, and heavy gasoline. In the light gasoline hydrogenation unit, the feed pump is located on the mixing pipeline of light gasoline and circulating oil, and the feed heater is located on the mixing pipeline of the mixture and circulating hydrogen. The feed end of the light gasoline hydrogenation reactor (fixed-bed reactor, internally filled with hydrogenation catalyst) is connected to the light gasoline extraction pipeline of the fractionation tower and the circulating oil via a pipeline. The pipelines and circulating hydrogen pipelines are connected. The high-precision tank is connected to the discharge pipeline of the light gasoline hydrotreating reactor for gas-liquid separation. The circulating hydrogen compressor is connected to the gas phase discharge pipeline of the high-precision tank, with an outlet pressure of 2.6 MPa, used to pressurize the circulating hydrogen and mix it with fresh hydrogen before delivering it to each hydrogen mixing point. The stabilizer is connected to the liquid phase discharge pipeline of the high-precision tank. The top is connected to a reflux tank and related pipelines to handle non-condensable gases, and the bottom is equipped with a circulation pipeline and a product output pipeline for heating and stripping the hydrotreated light gasoline. The naphtha hydrotreating unit is connected to the middle gasoline extraction pipeline of the fractionation tower to send the middle gasoline to the naphtha hydrotreating unit. The diesel hydrocracking unit is connected to the heavy gasoline extraction pipeline of the fractionation tower to send the heavy gasoline to the diesel hydrocracking unit.
[0037] Through the combination of the above process steps and equipment, the complete conversion of catalytic gasoline into chemical feedstock is achieved, meeting the refinery's demand for reduced gasoline production and increased ethylene and aromatic feedstock production.
[0038] Table 1: Distillation Range Analysis of Medium-Grade Gasoline (Properties of Medium-Grade Gasoline D86)
[0039]
[0040] Table 2 shows the gasoline composition (PONA) analysis (gasoline PONA analysis data).
[0041]
[0042] Table 3: Distillation Range Analysis of Heavy Gasoline (D86 Heavy Gasoline Distillation Range)
[0043]
[0044] The following is an explanation of Tables 1, 2, and 3:
[0045] Table 1: Distillation Range Analysis of Middle-Blended Gasoline. The D86 distillation range determination method was used to analyze the distillation range of middle-blended gasoline. The results show: Initial boiling point (IBP) is 84.8℃; 10% distillate temperature is 98.2℃; 30% distillate temperature is 104.3℃; 50% distillate temperature is 111.8℃; 70% distillate temperature is 122.3℃; 90% distillate temperature is 139.3℃; and final boiling point (EBP) is 162.5℃. This distillation range (approximately 84.8℃-162.5℃) indicates the distillation characteristics of middle-blended gasoline, providing a basis for its suitability as a reforming feedstock.
[0046] Table 2: Composition Analysis of Medium-Sized Gasoline (PONA), expressed as mass fraction (wt%). The table analyzes the content of alkanes (P), alkenes (O), cycloalkanes (N), and aromatics (A) with different carbon numbers (C6-C11) in medium-sized gasoline, as well as the total values of each carbon group and all categories. Specifically: In terms of carbon number distribution, C7 and C8 components account for a large proportion (C7 total 38.83 wt%, C8 total 37.19 wt%), C12 is almost non-existent, and C11 content is also low (C11 total 0.16 wt%). In terms of substance type, aromatics (A) total 33.95 wt%, alkanes (P) total 32.96 wt%, alkenes (O) total 17.61 wt%, and cycloalkanes (N) total 15.49 wt%. These compositional data indicate that the content of aromatics and alkanes in medium-sized gasoline is relatively high, and because the proportion of low-heavy carbon groups is low, it will not adversely affect the regeneration rate of the reforming catalyst when used as reforming feedstock.
[0047] Table 3: Distillation Range Analysis of Heavy Gasoline. The distillation range of heavy gasoline was analyzed using the D86 distillation range determination method. The results are as follows: Initial Boiling Point (IBP) 157.7℃; 10% distillation temperature 167.5℃; 30% distillation temperature 172.5℃; 50% distillation temperature 178.6℃; 70% distillation temperature 187.3℃; 90% distillation temperature 203℃; Final Boiling Point (EBP) 226.2℃. This distillation range (approximately 157.7℃-226.2℃) indicates that the heavy gasoline fraction is heavier and can meet the distillation range requirements of diesel hydrocracking units for blending feedstocks.
[0048] Finally, it should be noted that the present invention is not limited to the above embodiments, and many variations are possible. All variations that can be directly derived or conceived by those skilled in the art from the disclosure of the present invention should be considered within the scope of protection of the present invention.
Claims
1. A catalytic gasoline hydrogenation process for the production of chemical feedstocks, characterized in that, The process comprises the following steps: Step 1: The full-range stable gasoline is subjected to pre-hydrogenation reaction under the conditions of a pressure of 2.3 MPa and a temperature of 120-130℃, so that the diene content of the light gasoline product after reaction is reduced to within 200 ppm and the sulfur content is within 15 ppm; Step 2: The material after pre-hydrogenation reaction is fed into a fractionating column for separation of light, medium and heavy components, the column pressure is controlled at 0.68 MPa, the column bottom temperature is controlled at 289℃, and the light gasoline and medium gasoline withdrawal amounts are adjusted so that the light gasoline end boiling point is <70℃, the medium gasoline D86 distillation range is 75-175℃, and the heavy gasoline initial boiling point is >155℃; Step 3: After mixing light gasoline and cycle oil with a mass ratio of 2:1, pressurizing to 2.6 MPa by a feeding pump and mixing with cycle hydrogen, heating to 170℃ by a feeding heater, the mixture enters the light gasoline hydrogenation reactor, and full olefin saturation reaction occurs under the conditions of a reaction pressure of 2.3 MPa, a cycle hydrogen flow of 110000 Nm 3 / h, a cycle flow of 60 t / h, and a reactor outlet temperature of 262.5℃; Step 4: The hydrogen-carrying light gasoline in the high separation tank is subjected to gas-liquid separation, the separated recycled hydrogen is pressurized to 2.6 MPa by a recycled hydrogen compressor and then mixed with fresh hydrogen and delivered to each hydrogen mixing point; Step 5: The hydrogen-carrying light gasoline containing dissolved hydrogen from the high separation tank is fed into a stabilizing column, the column pressure is controlled at 0.7 MPa, the column bottom temperature is controlled at 112℃, and the reflux ratio is controlled at 10.8 (mass fraction) for temperature stripping, so that the hydrogen content of the column bottom hydrogen-carrying light gasoline is <0.001%, the olefin content is <1% (mass fraction), and a part of the hydrogen-carrying light gasoline is recycled to the raw material part, and the other part is delivered to an ethylene device as a qualified product as cracking raw material; Step 6: The medium gasoline is withdrawn from the middle part of the fractionating column and delivered to a naphtha hydrogenation device for blending and then used as reforming raw material to produce aromatic products; Step 7: The heavy gasoline is withdrawn from the bottom part of the fractionating column and delivered to a diesel hydrocracking device for blending to produce liquefied gas and heavy naphtha.
2. The catalytic gasoline hydrogenation process for producing chemical raw materials according to claim 1, characterized in that, The full-range stable gasoline in Step 1 is catalytic cracking device stable gasoline.
3. The catalytic gasoline hydrogenation method for producing chemical raw materials according to claim 1, characterized in that, The temperature rise of the light gasoline hydrogenation reactor in Step 3 when performing full-olefin saturation reaction is 92.5℃.
4. The catalytic gasoline hydrogenation process for producing chemical raw materials according to claim 1, characterized in that, The molar fraction of hydrogen in the hydrogen-carrying light gasoline in Step 5 is 1.45%.
5. A catalytic gasoline hydrogenation plant for the production of chemical feedstocks, for carrying out the process according to any one of claims 1 to 4, characterized by the fact that, The process comprises: a pre-hydrogenation reactor for pre-hydrogenation reaction of full-range stable gasoline; A fractionating tower is connected with a discharge pipeline of the pre-hydrogenation reactor, and is used for separating light gasoline, middle gasoline and heavy gasoline. A middle gasoline extraction pipeline is arranged in the middle of the fractionating tower, and a heavy gasoline extraction pipeline is arranged at the bottom of the fractionating tower. A light gasoline hydrogenation unit comprises a feed pump, a feed heater, a light gasoline hydrogenation reactor and a high separation tank. The feed end of the light gasoline hydrogenation reactor is connected with the light gasoline extraction pipeline, the circulation oil pipeline and the circulation hydrogen pipeline of the fractionating tower through pipelines. The feed pump is arranged on a mixed pipeline of light gasoline and circulation oil. The feed heater is arranged on a mixed pipeline of mixed material and circulation hydrogen. The high separation tank is connected with a discharge pipeline of the light gasoline hydrogenation reactor, and is used for gas-liquid separation. A circulation hydrogen compressor is connected with a gas phase discharge pipeline of the high separation tank, and is used for pressurizing circulation hydrogen, mixing the circulation hydrogen with new hydrogen and delivering the mixture to each hydrogen mixing point. A stabilizing tower is connected with a liquid phase discharge pipeline of the high separation tank, and is used for heating stripping of hydrogenated light gasoline. A circulation pipeline and a product output pipeline are arranged at the bottom of the stabilizing tower. A naphtha hydrogenation device connection pipeline is connected with the middle gasoline extraction pipeline of the fractionating tower, and is used for delivering middle gasoline to the naphtha hydrogenation device. A diesel hydrocracking device connection pipeline is connected with the heavy gasoline extraction pipeline of the fractionating tower, and is used for delivering heavy gasoline to the diesel hydrocracking device.
6. A catalytic gasoline hydrogenation apparatus for producing a chemical material according to claim 5, wherein A feed tank is connected with the feed end of the pre-hydrogenation reactor through a feed pump, and is used for storing catalytic gasoline.
7. A catalytic gasoline hydrogenation apparatus for producing a chemical material according to claim 5, wherein A light gasoline extraction pipeline is arranged at the top of the fractionating tower, and a reflux tank is connected with the light gasoline extraction pipeline, and is used for treatment of non-condensable gas after light gasoline separation.
8. The catalytic gasoline hydrogenation apparatus for producing chemical raw materials according to claim 5, characterized in that, A reflux tank is connected with the top of the stabilizing tower, and is used for treatment of non-condensable gas of the stabilizing tower.
9. The catalytic gasoline hydrogenation apparatus for producing chemical raw materials according to claim 5, characterized in that, The light gasoline hydrogenation reactor is a fixed bed reactor, and is internally filled with hydrogenation catalyst.
10. The catalytic gasoline hydrogenation apparatus for producing chemical raw materials according to claim 5, characterized in that, The outlet pressure of the circulation hydrogen compressor is 2.6 MPa.