A continuous re-contact method and system for re-reforming

Abstract

This disclosure relates to a continuous reforming re-contact method and system, the system comprising: a primary re-contact air cooler (1), a re-contact tower (2), a secondary reforming hydrogen booster (3), a secondary re-contact air cooler (4), a re-contact precooler (6), a re-contact freezer (7), a secondary re-contact tank (8), and a reforming product separator bottom pump (9). Using the method and system of this disclosure, while achieving the same or better reforming hydrogen purity and liquid yield as existing methods, the re-contact temperature is effectively increased, thereby reducing the refrigerant requirements for re-contact. This eliminates the need for or reduces the load on refrigeration compressor units, effectively reducing the load on the re-contact precooler, re-contact freezer, and secondary re-contact air cooler, meeting the requirements of modern refining units for reduced investment, energy consumption, and land use.

Description

Technical Field

[0001] This disclosure relates to the field of oil refining technology, and more specifically, to a continuous reforming re-contact method and system. Background Technology

[0002] Catalytic reforming is an important petroleum processing technique. Under the action of a catalyst, the molecular structure of hydrocarbons in gasoline fractions can be rearranged, thereby converting naphtha into high-octane reformed gasoline, liquefied petroleum gas, and reformed hydrogen rich in aromatics. This increases the yield of aromatic products while also improving the octane number of the gasoline.

[0003] Early catalytic reforming processes, conducted at low pressures, led to severe catalyst deactivation due to coking. The first-generation continuous catalytic reforming process developed by UOP (Universal Optics, Inc.) achieved uninterrupted catalyst regeneration at 0.8 MPa. Subsequent second- and third-generation continuous reforming processes further improved the continuous regeneration capability of the catalyst while reducing the reaction pressure to 0.35 MPa to achieve higher product yields. However, the excessively low reaction pressure resulted in a high concentration of light hydrocarbons mixed in with the byproduct reformed hydrogen under this low-pressure equilibrium, leading to low reformed hydrogen purity. To address this issue, a re-contact section was introduced in the continuous reforming process. This section involves adding a re-contact tank to allow the gas and liquid phases to re-contact under pressurized and low-temperature conditions, establishing a new material balance to reduce the light hydrocarbon content in the gas-phase reformed hydrogen and thus improve its purity. However, the re-contact requires a low temperature, necessitating a refrigeration system, which increases investment, energy consumption, and floor space requirements. Summary of the Invention

[0004] The purpose of this disclosure is to provide a continuous reforming re-contact method and system that, while achieving the same or better reformed hydrogen purity and liquid yield as existing methods, effectively increases the re-contact temperature, thereby reducing the refrigerant requirements for re-contact. This eliminates the need for or reduces the load on refrigeration compressor units, effectively reducing the load on the re-contact precooler, re-contact freezer, and secondary re-contact air cooler, thus meeting the requirements of modern oil refining units for reducing investment, energy consumption, and land use.

[0005] To achieve the above objectives, the first aspect of this disclosure provides a continuous re-reconnection method, the method comprising the following steps:

[0006] S1. The outlet gas of the first-stage booster is cooled down by the first-stage re-contact air cooler to obtain the cooled outlet gas of the first-stage booster. The cooled outlet gas of the first-stage booster enters the re-contact tower from the bottom and re-contacts the re-contact solvent from the top of the tower on the tower plate to obtain reformed oil and hydrogen-containing gas from the top of the re-contact tower.

[0007] S2. The hydrogen-containing gas at the top of the re-contact tower is pressurized by a two-stage reforming hydrogen booster to obtain pressurized hydrogen-containing gas at the top of the re-contact tower.

[0008] S3. The pressurized hydrogen-containing gas at the top of the re-contact tower is sent to the secondary re-contact air cooler for cooling and temperature reduction to obtain cooled hydrogen-containing gas at the top of the re-contact tower.

[0009] S4. Pressurize the bottom oil of the reforming product separator by the bottom pump of the reforming product separator to obtain pressurized bottom oil of the reforming product separator. Mix the pressurized bottom oil of the reforming product separator with the hydrogen-containing gas at the top of the cooling re-contact tower to obtain a gas-liquid mixture. Allow the gas-liquid mixture to enter the shell side of the re-contact precooler for heat exchange to obtain a shell side gas-liquid two-phase after heat exchange.

[0010] S5. The heat-exchanged shell-side gas-liquid two-phase system is sent to a re-contact freezer for further cooling to obtain a cooled gas-liquid two-phase system.

[0011] S6. The cooled gas-liquid two-phase mixture is sent to a secondary re-contact tank for re-contact, resulting in reformed hydrogen at the top of the re-contact tank and a cryogenic liquid phase at the bottom of the re-contact tank. The reformed hydrogen at the top of the re-contact tank is discharged from the top of the secondary re-contact tank, and the cryogenic liquid phase at the bottom of the re-contact tank enters the tube side of the re-contact precooler to exchange heat with the gas-liquid mixture, resulting in a tube-side liquid phase after heat exchange. This tube-side liquid phase after heat exchange is returned to the re-contact tower as a re-contact solvent.

[0012] Optionally, the outlet gas temperature of the first-stage booster is 70-150℃, and the pressure is 1.0-2.0MPa;

[0013] After being cooled by the first-stage re-contact air cooler, the outlet temperature of the first-stage booster compressor is 20-60℃, and the pressure is 1.0-2.0MPa.

[0014] Optionally, the re-contact tower is provided with 5-15 trays, the pressure of the first tray at the top of the tower is 1.0-2.0 MPa, and the pressure of each tray decreases layer by layer with a pressure drop of 5-30 kPa.

[0015] Optionally, the temperature of the hydrogen-containing gas at the top of the pressurized re-contact tower after being pressurized by the secondary reforming hydrogen booster is 70-150℃ and the pressure is 2.0-3.5MPa.

[0016] Optionally, the temperature of the hydrogen-containing gas at the top of the re-contact tower after being cooled by the secondary re-contact air cooler is 30-60°C, and the pressure is 2.0-3.5 MPa.

[0017] Optionally, the temperature of the bottom oil in the reforming product separator is 20-60℃, and the pressure is 0.2-1.0MPa;

[0018] The temperature of the pressurized bottom oil of the reforming product separator after being pressurized by the bottom pump is 20-60℃, and the pressure is 2.0-3.5MPa.

[0019] Optionally, after heat exchange in the re-contact precooler, the temperature of the shell-side gas-liquid two-phase system is 20-50°C, and the pressure is 2.0-3.5 MPa.

[0020] Optionally, the temperature of the heat-exchange tube-side liquid phase after heat exchange in the re-contact precooler is 20-50°C, and the pressure is 1.0-2.0 MPa.

[0021] Optionally, the cooled gas-liquid two-phase mixture, after being cooled by the re-contact freezer, enters the secondary re-contact tank at a temperature of 6-15°C and a pressure of 2.0-3.5 MPa.

[0022] A second aspect of this disclosure provides a continuous re-energizing re-contact system employing the method of the first aspect, the system comprising:

[0023] Primary re-contact air cooler, re-contact tower, secondary reforming hydrogen booster, secondary re-contact air cooler, re-contact precooler, re-contact freezer, secondary re-contact tank, reforming product separator bottom pump;

[0024] The outlet of the first-stage re-contact air cooler is connected to the bottom inlet of the re-contact tower; the top outlet of the re-contact tower is connected to the inlet of the second-stage reforming hydrogen booster; the outlet of the second-stage reforming hydrogen booster is connected to the inlet of the second-stage re-contact air cooler; the outlet of the second-stage re-contact air cooler is connected to the shell-side inlet of the re-contact precooler; the shell-side outlet of the re-contact precooler is connected to the inlet of the re-contact freezer; the outlet of the re-contact freezer is connected to the inlet of the second-stage re-contact tank; the bottom outlet of the second-stage re-contact tank is connected to the tube-side inlet of the re-contact precooler; the tube-side outlet of the re-contact precooler is connected to the top inlet of the re-contact tower; and the outlet of the bottom pump of the reforming product separator is connected to the shell-side inlet of the re-contact precooler.

[0025] Through the above technical solution, the continuous reforming re-contact method disclosed herein establishes gas-liquid equilibrium between the gas and liquid phases at the front end of the re-contact process, i.e., on the tray of the re-contact tower, by adding a re-contact tower. This reduces the content of light hydrocarbons in the hydrogen-containing gas in subsequent processes, thereby effectively improving the subsequent re-contact refrigeration system and the low temperature required for re-contact. While maintaining the reformed hydrogen purity and liquid yield of the existing re-contact process, the system disclosed herein can reduce the investment, energy consumption, and floor space of the equipment.

[0026] Other features and advantages of this disclosure will be described in detail in the following detailed description section. Attached Figure Description

[0027] The accompanying drawings are provided to further illustrate the present disclosure and form part of the specification. They are used together with the following detailed description to explain the present disclosure, but do not constitute a limitation thereof. In the drawings:

[0028] Figure 1 This is a flowchart of Example 1.

[0029] Figure 2 This is a flowchart of Comparative Example 1.

[0030] Explanation of reference numerals in the attached figures

[0031] 1. Primary re-contact air cooler; 2. Re-contact tower; 3. Secondary reforming hydrogen booster; 4. Secondary re-contact air cooler; 5. Primary re-contact tank; 6. Re-contact precooler; 7. Re-contact freezer; 8. Secondary re-contact tank; 9. Reforming product separator bottom pump.

[0032] 101 Bottom oil of reforming product separator; 102 Outlet gas of first-stage booster; 103 Cooled outlet gas of first-stage booster; 104 Hydrogen-containing gas at the top of the re-contact column; 105 Pressurized hydrogen-containing gas at the top of the re-contact column; 106 Cooled hydrogen-containing gas at the top of the re-contact column; 107 Gas-liquid mixture; 108 Shell-side gas-liquid two-phase after heat exchange; 109 Cooled gas-liquid two-phase; 110 Reformed hydrogen at the top of the re-contact tank; 111 Low-temperature liquid phase at the bottom of the re-contact tank; 112 Liquid phase in the tube side after heat exchange; 113 Pressurized bottom oil of reforming product separator; 114 Reforming oil. Detailed Implementation

[0033] The specific embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit this disclosure.

[0034] In this disclosure, unless otherwise stated, directional terms such as “bottom,” “tower top,” “tower bottom,” “tank top,” and “tank bottom” generally refer to the bottom, tower top, tower bottom, tank top, and tank bottom of the device in normal use.

[0035] like Figure 1As shown, the first aspect of this disclosure provides a continuous reforming re-contact method, the method comprising the following steps: S1, cooling the outlet gas 102 of the first-stage booster compressor through a first-stage re-contact air cooler 1 to obtain cooled outlet gas 103 of the first-stage booster compressor, and then allowing the cooled outlet gas 103 of the first-stage booster compressor to enter the re-contact tower 2 from the bottom and re-contact the re-contact solvent from the top of the tower on the tower plate to obtain reformed oil 114 and hydrogen-containing gas 104 from the top of the re-contact tower;

[0036] S2. The hydrogen-containing gas 104 at the top of the re-contact tower is pressurized by the secondary reforming hydrogen booster 3 to obtain the pressurized hydrogen-containing gas 105 at the top of the re-contact tower.

[0037] S3. The pressurized hydrogen-containing gas 105 from the top of the re-contact tower is sent to the secondary re-contact air cooler 4 for cooling and temperature reduction to obtain the cooled hydrogen-containing gas 106 from the top of the re-contact tower.

[0038] S4. The reforming product separator bottom oil 101 is pressurized by the reforming product separator bottom pump 9 to obtain pressurized reforming product separator bottom oil 113. The pressurized reforming product separator bottom oil 113 is mixed with the cooled and de-cooled hydrogen-containing gas 106 from the top of the re-contact tower to obtain a gas-liquid mixture 107. The gas-liquid mixture 107 is then introduced into the shell side of the re-contact precooler 6 for heat exchange to obtain a heat-exchanged shell side gas-liquid two-phase 108.

[0039] S5. The heat-exchanged shell-side gas-liquid two-phase 108 is sent to the re-contact freezer 7 for further cooling to obtain a cooled gas-liquid two-phase 109.

[0040] S6. The cooled gas-liquid two-phase 109 is sent to the secondary re-contact tank 8 for re-contact of the gas and liquid phases, resulting in reformed hydrogen 110 at the top of the re-contact tank and cryogenic liquid phase 111 at the bottom of the re-contact tank. The reformed hydrogen 110 at the top of the re-contact tank is discharged from the top of the secondary re-contact tank 8, and the cryogenic liquid phase 111 at the bottom of the re-contact tank enters the tube side of the re-contact precooler 6 to exchange heat with the gas-liquid mixture 107, resulting in tube side liquid phase 112 after heat exchange. The tube side liquid phase 112 after heat exchange is returned to the re-contact tower 2 as a re-contact solvent.

[0041] Using the method disclosed herein, the outlet gas from the first-stage booster compressor and the circulating liquid phase from the bottom of the re-contact tank undergo gas-liquid phase contact in a re-contact tower, respectively, from bottom to top and from top to bottom, to achieve gas-liquid equilibrium. Light hydrocarbons in the hydrogen-containing gas at the top of the tower dissolve in the liquid oil. The purified hydrogen-containing gas from the top of the tower exits from the top of the re-contact tower and enters the subsequent re-contact process, while the liquid reforming oil exits from the bottom of the tower. This method can reduce the light hydrocarbon content in the hydrogen-containing gas in subsequent processes, thereby effectively increasing the temperature required for the subsequent re-contact refrigeration system and re-contact. It can eliminate the need for a refrigeration compressor unit or reduce its load, effectively reducing the load on the re-contact precooler, re-contact refrigeration unit, and second-stage re-contact air cooler. While maintaining the existing reformed hydrogen purity and liquid yield, this system can reduce the investment, energy consumption, and floor space required for the plant.

[0042] In this disclosure, the temperature and pressure of the first-stage booster outlet gas, the cooled first-stage booster outlet gas, and the hydrogen-containing gas at the top of the re-contact tower can vary within a wide range. In one specific embodiment of this disclosure, the temperature of the first-stage booster outlet gas 102 can be 70-150°C, and the pressure can be 1.0-2.0 MPa; the temperature of the cooled first-stage booster outlet gas 103 after being cooled by the first-stage re-contact air cooler 1 can be 20-60°C, and the pressure can be 1.0-2.0 MPa.

[0043] In one specific embodiment of this disclosure, the re-contact tower 2 may be provided with 5-15 layers of trays, the pressure of the first tray at the top of the tower may be 1.0-2.0 MPa, and the pressure of each tray may decrease layer by layer with a pressure drop of 5-30 kPa.

[0044] In this disclosure, the re-contact tower 2 is equipped with 5-15 trays. Because multiple trays can form gas-liquid equilibrium at different temperature layers, under appropriate trays and pressures, light and heavy components can re-establish equilibrium on each tray. The gaseous hydrogen-containing gas and liquid oil re-contact each other on the trays. The purified hydrogen-containing gas at the top of the tower exits from the top of the re-contact tower and enters the subsequent re-contact process, while the liquid reforming oil exits from the bottom of the tower.

[0045] In this disclosure, the hydrogen-containing gas 104 at the top of the re-contact column contains hydrogen, light hydrocarbons with 1-4 carbon atoms, and hydrocarbons with 5 or more carbon atoms; specifically, the molar content of hydrogen in the hydrogen-containing gas 104 at the top of the re-contact column can be 80-86%, and the molar content of hydrocarbons with 5 or more carbon atoms in the hydrogen-containing gas 104 at the top of the re-contact column is not greater than 3.0%, preferably not greater than 2%.

[0046] In this disclosure, the temperatures and pressures of the pressurized hydrogen-containing gas at the top of the re-contact column, the cooled hydrogen-containing gas at the top of the re-contact column, the bottom oil of the reforming product separator, the pressurized bottom oil of the reforming product separator, the shell-side gas-liquid two-phase gas after heat exchange, and the tube-side liquid phase after heat exchange can vary within a wide range. In one specific embodiment of this disclosure, the temperature of the pressurized hydrogen-containing gas 105 at the top of the re-contact column after being pressurized by the secondary reforming hydrogen booster 3 can be 70-150°C, and the pressure can be 2.0-3.5 MPa. In one specific embodiment of this disclosure, the temperature of the cooled hydrogen-containing gas 106 at the top of the re-contact column after being cooled by the secondary re-contact air cooler 4 can be 30-60°C, and the pressure can be 2.0-3.5 MPa. In one specific embodiment of this disclosure, the temperature of the bottom oil 101 of the reforming product separator can be 20-60°C, and the pressure can be 0.2-1.0 MPa; the temperature of the pressurized bottom oil 113 of the reforming product separator after being pressurized by the bottom pump 9 can be 20-60°C, and the pressure can be 2.0-3.5 MPa. In one specific embodiment of this disclosure, the temperature of the shell-side gas-liquid two-phase 108 after heat exchange in the re-contact precooler 6 can be 20-50°C, and the pressure can be 2.0-3.5 MPa; the temperature of the tube-side liquid phase 112 after heat exchange in the re-contact precooler 6 can be 20-50°C, and the pressure can be 1.0-2.0 MPa.

[0047] In one specific embodiment of this disclosure, the cooled gas-liquid two-phase 109, after being cooled by the re-contact freezer 7, can enter the secondary re-contact tank 8 under conditions of 6-15°C and 2.0-3.5MPa.

[0048] A second aspect of this disclosure provides a continuous re-energizing re-contact system employing the method of the first aspect, the system comprising:

[0049] The system comprises a primary re-contact air cooler 1, a re-contact tower 2, a secondary reforming hydrogen booster 3, a secondary re-contact air cooler 4, a re-contact precooler 6, a re-contact freezer 7, a secondary re-contact tank 8, and a reforming product separator bottom pump 9. In one specific embodiment of this disclosure, the outlet of the primary re-contact air cooler 1 is connected to the bottom inlet of the re-contact tower 2; the top outlet of the re-contact tower 2 is connected to the inlet of the secondary reforming hydrogen booster 3; and the outlet of the secondary reforming hydrogen booster 3 is connected to the inlet of the secondary re-contact air cooler 4. The outlet of the re-contact air cooler 4 is connected to the shell-side inlet of the re-contact precooler 6; the shell-side outlet of the re-contact precooler 6 is connected to the inlet of the re-contact freezer 7; the outlet of the re-contact freezer 7 is connected to the inlet of the secondary re-contact tank 8; the bottom outlet of the secondary re-contact tank 8 is connected to the tube-side inlet of the re-contact precooler 6; the tube-side outlet of the re-contact precooler 6 is connected to the top inlet of the re-contact tower 2; and the outlet of the reformate separator bottom pump 9 is connected to the shell-side inlet of the re-contact precooler 6.

[0050] The present disclosure will be further illustrated by the following examples, but the present disclosure is not limited thereto.

[0051] Example 1

[0052] The main raw material logistics disclosed herein include:

[0053] The bottom oil 101 of the reforming product separator was stored at a temperature of 46℃ and a pressure of 0.24MPa.

[0054] The outlet gas of the first-stage booster compressor, with a temperature of 132℃ and a pressure of 1.40MPa, is 102.

[0055] The raw material composition applicable to this embodiment is shown in Table 1 below. It should be noted that this raw material composition is exemplary and should not be limited to the composition listed herein.

[0056] Table 1. Raw material composition

[0057]

[0058] like Figure 1 As shown, the first-stage re-contact air cooler 1 cools the outlet gas 102 of the first-stage booster to a gas-liquid mixture with a temperature of 46°C and a pressure of 1.38MPa. This gas-liquid mixture enters the re-contact tower 2 from the bottom of the tower.

[0059] Inside the re-contact column 2, the gaseous hydrogen-containing gas and the liquid oil undergo a second contact. A single-stage distillation column without a top condenser and a bottom reboiler can be used as the re-contact column 2, employing six theoretical trays. The liquid stream enters the column from the top tray (first tray), while the gas-liquid two-phase stream enters from the bottom tray (sixth tray). The pressure on the top tray is 1.34 MPa, and the pressure drop decreases by 10 kPa for each tray. The purified hydrogen-containing gas exits from the top of the re-contact column 2, while the liquid reformate 114 exits from the bottom.

[0060] In the secondary reforming hydrogen booster 3, the hydrogen-containing gas 104 from the top of the re-contact tower 2 is 38 o Temperature C and pressure 1.34 MPa are increased to 2.81 MPa by the secondary reforming hydrogen booster 3, wherein the molar content of hydrogen in the hydrogen-containing gas 104 at the top of the re-contact column is 85%.

[0061] In the secondary re-contact air cooler 4, the temperature after pressurization is 119°C. o C. The hydrogen-containing gas 105 at the top of the re-contact tower, pressurized to 2.81 MPa, is cooled to 45°C. o C, the cooled hydrogen-containing gas 106 from the top of the re-contacting tower, at a temperature of 45℃ and a pressure of 2.79MPa, is then pressurized by the bottom pump 9 of the reforming product separator to a temperature of 46℃. o C. The reforming product separator bottom oil 113 with a pressure of 2.94 MPa is mixed, and the resulting gas-liquid mixture 107 is fed into the shell side of the re-contact precooler 6.

[0062] In the re-contact precooler 6, 48 o C's gas-liquid mixture 107 and 11 o In the secondary re-contact tank 8 of C, the temperature of the gas-liquid mixture is reduced to 32°C through a low-temperature liquid phase heat exchange at the bottom of the re-contact tank 111. o C, so that the shell-side gas-liquid two-phase 108, which has reached a temperature of 32℃ and a pressure of 2.78MPa, enters the re-contact refrigerator 7.

[0063] In the re-contact freezer 7, the hydrogen-containing gas and liquid-phase oil-gas-liquid mixture (i.e., the shell-side gas-liquid two-phase 108 after heat exchange) is further cooled, resulting in a temperature of 11. o C. The cooled gas-liquid two-phase gas 109, with a pressure of 2.77 MPa, enters the secondary re-contact tank 8, where gas and liquid re-contact occur.

[0064] In the secondary re-contact tank 8, a new gas-liquid balance is established. The purified reformed hydrogen exits the tower from the top of the secondary re-contact tank 8. The low-temperature liquid phase 111 at the bottom of the secondary re-contact tank 8 is heat-exchanged by the re-contact precooler 6 to obtain the heat-exchanged tube-side liquid phase 112. The heat-exchanged tube-side liquid phase 112 with a temperature of 37°C and a pressure of 1.51 MPa is sent back to the re-contact tower 2 and enters the tower from the top under the conditions of a temperature of 37°C and a pressure of 1.51 MPa.

[0065] Comparative Example 1

[0066] The difference from the embodiment is that, in terms of equipment configuration, it includes a primary re-contact tank 5, which is replaced by the re-contact tower 2 in embodiment 1. Therefore, there are two re-contact tanks in the comparative example, namely the primary re-contact tank 5 and the secondary re-contact tank 8. In terms of process setup, after the outlet gas of the primary booster and the bottom circulating liquid phase oil of the secondary re-contact tank 8 are mixed, they are cooled down by the primary re-contact air cooler and then enter the primary re-contact tank 5. Gas-liquid balance is established, and the reformed oil is separated from the bottom of the primary re-contact tank 5. The top gas of the primary re-contact tank 5 then enters the same subsequent secondary re-contact process as in the embodiment.

[0067] like Figure 2 As shown, in the first-stage re-contact air cooler 1, the outlet gas of the first-stage booster compressor is at a rate of 69... o C enters the first-stage re-contact air cooler 1 and is cooled to 46°C by the air cooler 1. o C.

[0068] In the second-stage reforming hydrogen booster 3, the hydrogen-containing gas from the top of the first-stage re-contact tank 5 is at a rate of 46... o Temperature C and pressure 1.38 MPa are increased to 2.81 MPa by the secondary reforming hydrogen booster 3.

[0069] In the secondary re-contact air cooler 4, the pressure is increased to 117. o The hydrogen-containing gas at C was cooled to 45°C. o After C, it is pressurized by the bottom pump of the reforming product separator to 46 o After being mixed with the bottom oil of the reformate separator at temperature C and pressure 2.94 MPa, the mixture enters the shell side of the re-contact precooler 6.

[0070] In the re-contact precooler 6, 50 o C's gas-liquid mixture with 4 o In the secondary re-contact tank (tank 8), heat exchange of the bottom liquid phase material reduced the temperature of the gas-liquid mixture to 29°C. o After C, it enters the re-contact freezer 7.

[0071] In the re-contact freezer 7, the hydrogen-containing gas and liquid oil-gas-liquid mixture is further cooled to 4 o At temperature C and pressure 2.77 MPa, the gas-liquid mixture enters the secondary re-contact tank 8, where it undergoes re-contact.

[0072] In the secondary re-contact tank 8, a new gas-liquid balance is established. The purified reformed hydrogen is pushed out from the secondary re-contact tank 8, and the bottom liquid phase of the secondary re-contact tank 8 is sent back to the front of the primary re-contact air cooler 1 after heat exchange in the re-contact precooler 6.

[0073] Table 2. Purity of Reformed Hydrogen 110

[0074]

[0075] Table 3. Load of Re-contact Precooler 6, Re-contact Refrigerator 7, Secondary Re-contact Air Cooler 4

[0076]

[0077] As can be seen from the data in Table 2, compared with the existing continuous reforming unit re-contact process, the hydrogen purity and reformed liquid product yield of this disclosure are at a better level. By comparing Example 1 and Comparative Example 1, it can be seen that the low temperature of 4°C required for the second-stage re-contact in Comparative Example 1 can be significantly increased to 11°C by this disclosure. As can be seen from the data in Table 3, the increase in temperature effectively reduces the load of the re-contact precooler, re-contact freezer and second-stage re-contact air cooler, which can eliminate the refrigeration compressor unit or reduce its load, thereby reducing the investment, energy consumption and footprint of the refrigeration unit.

[0078] The preferred embodiments of this disclosure have been described in detail above with reference to the accompanying drawings. However, this disclosure is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this disclosure, various simple modifications can be made to the technical solutions of this disclosure, and these simple modifications all fall within the protection scope of this disclosure.

[0079] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, this disclosure will not describe the various possible combinations separately.

[0080] Furthermore, various different embodiments of this disclosure can be combined in any way, as long as they do not violate the spirit of this disclosure, they should also be regarded as the content disclosed in this disclosure.

Claims

1. A continuous re-contact reforming method, characterized in that, The method includes the following steps: S1. The outlet gas (102) of the first-stage booster is cooled down by the first-stage re-contact air cooler (1) to obtain the cooled outlet gas (103) of the first-stage booster. The cooled outlet gas (103) of the first-stage booster enters the re-contact tower (2) from the bottom and re-contacts the re-contact solvent from the top of the tower on the tower plate to obtain reformed oil (114) and hydrogen-containing gas (104) from the top of the re-contact tower. The re-contact tower (2) is provided with 5-15 tower plates. The pressure of the first tower plate at the top of the tower is 1.0-2.0 MPa, and the pressure of each tower plate decreases by 5-30 kPa. S2. The hydrogen-containing gas (104) at the top of the re-contact tower is pressurized by the secondary reforming hydrogen booster (3) to obtain pressurized hydrogen-containing gas (105) at the top of the re-contact tower. S3. The pressurized hydrogen-containing gas (105) at the top of the re-contact tower is sent to the secondary re-contact air cooler (4) for cooling and temperature reduction to obtain the cooled hydrogen-containing gas (106) at the top of the re-contact tower. S4. Pressurize the bottom oil (101) of the reforming product separator by the bottom pump (9) to obtain pressurized bottom oil (113). Mix the pressurized bottom oil (113) with the cooled hydrogen-containing gas (106) at the top of the re-contact tower to obtain a gas-liquid mixture (107). Allow the gas-liquid mixture (107) to enter the shell side of the re-contact precooler (6) for heat exchange to obtain a heat-exchanged shell side gas-liquid two-phase (108). S5. The heat exchanged shell-side gas-liquid two-phase (108) is sent to the re-contact freezer (7) for further cooling to obtain a cooled gas-liquid two-phase (109). S6. The cooled gas-liquid two-phase (109) is sent to the secondary re-contact tank (8) for re-contact of the gas-liquid two-phase, to obtain reformed hydrogen (110) at the top of the re-contact tank and low-temperature liquid phase (111) at the bottom of the re-contact tank. The reformed hydrogen (110) at the top of the re-contact tank is discharged from the top of the secondary re-contact tank (8), and the low-temperature liquid phase (111) at the bottom of the re-contact tank enters the tube side of the re-contact precooler (6) to exchange heat with the gas-liquid mixture (107), to obtain the tube side liquid phase (112) after heat exchange, and the tube side liquid phase (112) after heat exchange is returned to the re-contact tower (2) as the re-contact solvent.

2. The method according to claim 1, wherein, The temperature of the outlet gas (102) of the first-stage booster is 70-150℃, and the pressure is 1.0-2.0MPa; The temperature of the cooled first-stage booster outlet gas (103) after being cooled by the first-stage re-contact air cooler (1) is 20-60℃ and the pressure is 1.0-2.0MPa.

3. The method according to claim 1, wherein, The temperature of the hydrogen-containing gas (105) at the top of the re-contact tower after being pressurized by the secondary reforming hydrogen booster (3) is 70-150℃ and the pressure is 2.0-3.5MPa.

4. The method according to claim 1, wherein, The temperature of the hydrogen-containing gas (106) at the top of the re-contact tower after being cooled by the secondary re-contact air cooler (4) is 30-60°C and the pressure is 2.0-3.5MPa.

5. The method according to claim 1, wherein, The temperature of the bottom oil (101) in the reforming product separator is 20-60℃, and the pressure is 0.2-1.0MPa; The temperature of the pressurized bottom oil (113) of the reforming product separator after being pressurized by the bottom pump (9) is 20-60℃ and the pressure is 2.0-3.5MPa.

6. The method according to claim 1, wherein, After heat exchange in the re-contact precooler (6), the temperature of the shell-side gas-liquid two-phase (108) is 20-50℃ and the pressure is 2.0-3.5MPa.

7. The method according to claim 1, wherein, The temperature of the tube-side liquid phase (112) after heat exchange in the re-contact precooler (6) is 20-50℃ and the pressure is 1.0-2.0MPa.

8. The method according to claim 1, wherein, After being cooled by the re-contact freezer (7), the cooled gas-liquid two-phase (109) enters the secondary re-contact tank (8) at a temperature of 6-15°C and a pressure of 2.0-3.5MPa.

9. A continuous re-reforming and re-contacting system employing the method described in any one of claims 1-8, characterized in that, The system includes: The primary re-contact air cooler (1), re-contact tower (2), secondary reforming hydrogen booster (3), secondary re-contact air cooler (4), re-contact precooler (6), re-contact freezer (7), secondary re-contact tank (8), and reforming product separator bottom pump (9). The outlet of the first-stage re-contact air cooler (1) is connected to the bottom inlet of the re-contact tower (2); the top outlet of the re-contact tower (2) is connected to the inlet of the second-stage re-contact air cooler (4) through the second-stage reforming hydrogen booster (3); the outlet of the second-stage re-contact air cooler (4) is connected to the shell-side inlet of the re-contact precooler (6); the shell-side outlet of the re-contact precooler (6) is connected to the inlet of the second-stage re-contact tank (8) through the re-contact freezer (7); the bottom outlet of the second-stage re-contact tank (8) is connected to the tube-side inlet of the re-contact precooler (6); the tube-side outlet of the re-contact precooler (6) is connected to the top inlet of the re-contact tower (2); the inlet of the reforming product separator bottom pump (9) is connected to the bottom oil outlet of the reforming product separator, and the outlet is connected to the shell-side inlet of the re-contact precooler (6).

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