A system and method for simultaneously preparing aromatics and olefins from synthesis gas

Abstract

The present invention provides a system and method for the simultaneous preparation of aromatics and olefins from synthesis gas. The system comprises an aromatics synthesis unit, a first separation unit, an olefin synthesis unit, a second separation unit, and a third separation unit connected in series, and a light olefin conversion unit connected to the second separation unit. The present invention integrates two preparation routes of preparing aromatics and olefins from synthesis gas. Compared with the construction of a single system for preparing aromatics from synthesis gas and a single system for preparing olefins from synthesis gas, the construction investment of the integrated system is effectively reduced. Moreover, since the preparation of aromatics from synthesis gas needs to be completed under high pressure, this pressure is continuously utilized in the subsequent separation and preparation of olefins from synthesis gas, so that the synthesis energy consumption is greatly reduced. In addition, the present invention separates C5-C 10 The product can convert hydrocarbons into C2-C4 olefins and a small amount of aromatics, effectively improving the yield of olefins and aromatics, and increasing the proportion of light olefins and aromatics in the product gas.

Description

Technical Field

[0001] The present invention relates to the technical field of preparing aromatics and olefins from synthesis gas, and in particular to a system and method for simultaneously preparing aromatics and olefins from synthesis gas. Background Art

[0002] The one-step synthesis gas (syngas) to aromatics or olefins (syngas → aromatics / olefins) process is a rapidly developing technology. Its main advantages are a shorter process, lower investment, and lower carbon emissions. Compared with the traditional multi-step synthesis route, where syngas is first used to produce methanol, which is then used to produce aromatics or olefins (syngas → methanol → aromatics / olefins), this one-step process couples the high-pressure, low-temperature reaction environment (typically 4-8 MPa and 180-270°C for methanol synthesis) with a low-pressure, high-temperature reaction environment (typically 0.2-0.5 MPa and 350-500°C for methanol to olefins or aromatics). Currently, CO conversion rates in the one-step synthesis gas to aromatics or olefins process can reach 20%-50%, and aromatics or olefin selectivity can reach 50%-80%. However, challenges remain, such as difficulty matching reaction zones, difficulty designing catalysts, process continuity issues, and the need for continuous improvement in product selectivity. Moreover, when the CO conversion rate increases, the CO2 selectivity is difficult to control, and when the total yield of aromatics or olefins increases, the selectivity of light olefins and light aromatics decreases; these problems have not been well solved in the past decade. Summary of the Invention

[0003] In view of the above problems existing in the prior art, the present invention provides a system and method for the simultaneous preparation of aromatics and olefins from synthesis gas, thereby achieving the purpose of simultaneously producing aromatics and light olefins.

[0004] The specific content of the invention is as follows:

[0005] In a first aspect, the present invention provides a system for preparing aromatics and olefins from synthesis gas, comprising: an aromatics synthesis unit, an olefin synthesis unit, a light olefin conversion unit, and a plurality of separation units; wherein:

[0006] The aromatics synthesis unit, the first separation unit, the olefin synthesis unit, the second separation unit and the third separation unit are sequentially connected in series, and the second separation unit is connected to the light olefin conversion unit;

[0007] The aromatics synthesis device is used to catalytically convert synthesis gas into aromatics to obtain a first mixed gas containing aromatics;

[0008] The first separation device is used to receive and cool the first mixed gas to liquefy the aromatic hydrocarbons and water vapor therein, and the remaining second mixed gas consists of unreacted synthesis gas, CO2 and a small amount of alkanes;

[0009] The olefin synthesis device is used to receive the second mixed gas and fresh synthesis gas, and perform olefin conversion reaction to obtain C1-C 10 a third mixed gas of hydrocarbons;

[0010] The second separation device is used to receive and cool the third mixed gas, so that the water vapor and C5-C 10 The hydrocarbons are liquefied to leave a fourth mixed gas containing inorganic gases and C1-C4 hydrocarbons;

[0011] The third separation device is used to receive the fourth mixed gas and perform pressure swing adsorption to separate C2-C4 hydrocarbons from small molecule gases H2, CO, CO2 and CH4;

[0012] The light olefin conversion unit is used to receive the liquefied C5-C 10 hydrocarbons and convert them into C2-C4 olefins and a small amount of aromatics.

[0013] Optionally, the aromatics synthesis device is filled with a metal oxide-molecular sieve catalyst; wherein,

[0014] The metal oxide includes one or more of zinc oxide, gallium oxide and germanium oxide;

[0015] Molecular sieves include: one or more of ZSM-5, ZSM-11, and ZSM-22;

[0016] The aromatics synthesis unit has an operating temperature of 250-380°C and an operating pressure of 2.1-6.1 MPa.

[0017] Optionally, the first separation device is provided with a first temperature control device to cool the first mixed gas to liquefy the aromatic hydrocarbons and water vapor therein; wherein,

[0018] The temperature control range of the first temperature control device includes -20~0℃.

[0019] Optionally, the olefin synthesis device is filled with a catalyst whose active component is a metal carbide; wherein the metal carbide includes: one or more of iron carbide, cobalt carbide and nickel carbide;

[0020] The operating temperature of the olefin synthesis unit is 250-380°C.

[0021] Optionally, the second separation device cools the third mixed gas by setting a second temperature control device, so that the H2O, C5-C 10 The purpose of hydrocarbon liquefaction; wherein,

[0022] The temperature control range of the second temperature control device includes -60~-35℃.

[0023] Optionally, the third separation device includes a pressure sub-control device and a plurality of third separation sub-devices arranged in parallel, and the plurality of third separation sub-devices are all filled with adsorbent; wherein,

[0024] The adsorbent is an inorganic oxide, a molecular sieve or carbon, and the pore size of the adsorbent meets the requirement that more than 85% of the pore size is 0.4-0.5 nm.

[0025] Optionally, the light olefin conversion unit is filled with a molecular sieve or a metal-molecular sieve-based catalyst; wherein the metal is one or more of gallium, zinc, copper and manganese, and the molecular sieve is ZSM-5, ZSM-22 or ZSM-11;

[0026] The acid amount of the molecular sieve and the metal-molecular sieve based catalyst is 10 -5 -10 -3 mmol / g;

[0027] The light olefin conversion unit is provided with a third temperature control device, and the temperature control range of the third temperature control device includes 450-600°C.

[0028] In a second aspect, the present invention provides a method for simultaneously preparing aromatics and olefins from synthesis gas, which is applicable to the system for simultaneously preparing aromatics and olefins from synthesis gas as described in the first aspect. The method comprises:

[0029] Fill the reaction zone of the aromatics synthesis unit with a metal oxide-molecular sieve catalyst, fill the reaction zone of the olefin synthesis unit with a catalyst whose active component is a metal carbide, fill the reaction zone of the light olefin conversion unit with a molecular sieve or a metal-molecular sieve-based catalyst; fill the third separation unit with an adsorbent

[0030] Controlling the operating pressure of the aromatics synthesis unit to 2.1-6.1 MPa and the operating temperature to 250-380°C, controlling the operating temperature of the first separation unit to -20-0°C, controlling the operating temperature of the olefin synthesis unit to 250-380°C, controlling the operating temperature of the second separation unit to -60--35°C, and controlling the operating temperature of the light olefin conversion unit to 450-600°C;

[0031] Passing synthesis gas with a H2 / CO ratio of 1.5:1 to 2.2:1 into the aromatics synthesis unit to convert aromatics to obtain a first mixed gas containing aromatics;

[0032] Passing the first mixed gas into the first separation device to liquefy the aromatic hydrocarbons and water vapor in the first mixed gas, and leaving a second mixed gas composed of unreacted synthesis gas, CO2 and a small amount of alkanes;

[0033] The second mixed gas is introduced into the olefin synthesis unit as the reaction gas, and fresh synthesis gas is further added to carry out olefin conversion reaction to obtain C1-C 10 a third mixed gas of hydrocarbons;

[0034] The third mixed gas is passed into the second separation device, so that the water vapor and C5-C 10 The hydrocarbons are liquefied to leave a fourth mixed gas containing inorganic gases and C1-C4 hydrocarbons;

[0035] Passing the fourth mixed gas into a third separation device so that the adsorbent in the third separation device adsorbs C2-C4 hydrocarbons in the fourth mixed gas, and the remaining small molecular gases include H2, CO, CO2 and CH4;

[0036] The liquefied C5-C 10 The hydrocarbons are fed into the light olefin conversion unit to undergo light olefin conversion reaction to obtain C5-C 10 Hydrocarbons are converted into C2-C4 olefins and a small amount of aromatics;

[0037] The C2-C4 olefins generated in the light olefin conversion unit and the C2-C4 hydrocarbons obtained by adsorption in the third separation unit are combined and collected, and the aromatics generated in the light olefin conversion unit and the aromatics obtained by liquefaction in the first separation unit are combined and collected.

[0038] Optionally, in the olefin synthesis unit, the volume flow rate of the fresh synthesis gas introduced is 3-10 times that of the second mixed gas introduced.

[0039] Optionally, in the aromatics synthesis unit, the CO single-pass conversion rate is 40-60%, and the aromatics selectivity is 75%-90% based on the hydrocarbon base;

[0040] In the olefin synthesis device, the CO single-pass conversion rate is 90-98%; based on the hydrocarbon base, the olefin selectivity is 65%-80%, among which, based on the olefin base, the C2-C4 olefin selectivity is 65-85%.

[0041] Compared with the prior art, the present invention has the following advantages:

[0042] The present invention provides a system for preparing aromatics and olefins from synthesis gas, comprising: an aromatics synthesis unit, an olefin synthesis unit, a light olefin conversion unit, and a plurality of separation units; wherein the aromatics synthesis unit, the first separation unit, the olefin synthesis unit, the second separation unit, and the third separation unit are sequentially connected in series, and the second separation unit is connected to the light olefin conversion unit; the aromatics synthesis unit is used to catalytically convert synthesis gas into aromatics to obtain a first mixed gas containing aromatics; the first separation unit is used to receive and cool the first mixed gas to liquefy the aromatics and water vapor therein, leaving a second mixed gas composed of unreacted synthesis gas, CO2, and a small amount of alkanes; the olefin synthesis unit is used to receive the second mixed gas and fresh synthesis gas and perform an olefin conversion reaction to obtain a C1-C 10 The second separation device is used to receive and cool the third mixed gas, so that the water vapor and C5-C 10 The hydrocarbons are liquefied, and a fourth mixed gas containing inorganic gases and C1-C4 hydrocarbons remains; the third separation device is used to receive the fourth mixed gas and perform adsorption treatment to separate C2-C4 hydrocarbons from small molecule gases H2, CO, CO2 and CH4; the light olefin conversion device is used to receive the liquefied C5-C 10 hydrocarbons and convert them into C2-C4 olefins and a small amount of aromatics.

[0043] The present invention integrates the two production routes of producing aromatics from syngas and producing olefins from syngas. Compared with the construction of a single system for producing aromatics from syngas and a single system for producing olefins from syngas, the construction investment of the integrated system is effectively reduced. In addition, the present invention first produces aromatics from syngas in an aromatics synthesis unit. Since the production of aromatics from syngas needs to be completed under high pressure, this pressure is continuously utilized in the subsequent separation and production of olefins from syngas, which greatly reduces the energy consumption of the synthesis. In addition, the present invention separates C5-C 10 It can convert hydrocarbons into C2-C4 olefins and a small amount of aromatics, effectively improving the olefin yield (yield increased by 5-20%) and increasing the proportion of light olefins in the product gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0045] Figure 1 A schematic diagram of the system structure for preparing aromatics and olefins from synthesis gas provided by an embodiment of the present invention is shown;

[0046] Figure 2 A flow chart of a method for simultaneously preparing aromatics and olefins from synthesis gas provided by an embodiment of the present invention is shown.

[0047] Description of reference numerals:

[0048] 1. Aromatics synthesis unit; 2. First separation unit; 3. Olefin synthesis unit; 4. Second separation unit; 5. Third separation unit; 6. Light olefin conversion unit; 7. First transmission pipeline; 8. Second transmission pipeline; 9. Fourth transmission pipeline; 10. Sixth transmission pipeline; 11. Eighth transmission pipeline; 12. Ninth transmission pipeline; 13. Tenth transmission pipeline 13; 14. Seventh transmission pipeline; 15. Second outlet; 16. Eleventh transmission pipeline; 17. Third transmission pipeline; 18. First outlet; 19. Fifth transmission pipeline 19; 20. Third outlet. DETAILED DESCRIPTION

[0049] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means a limitation on the present invention and its application or use. Based on the embodiments of the present invention, any product that is identical or similar to the present invention and is obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with other prior arts falls within the scope of protection of the present invention. In addition, all other embodiments obtained by ordinary technicians in this field without carrying out creative work fall within the scope of protection of the present invention.

[0050] Where specific experimental steps or conditions are not specified in the examples, the conventional experimental steps or conditions described in the prior art in the art may be used. Reagents and other instruments used, for which the manufacturer is not specified, are commercially available conventional reagent products. Furthermore, the accompanying drawings are merely schematic illustrations of embodiments of the present invention and are not necessarily drawn to scale. Identical reference numerals in the figures denote identical or similar parts, and their repeated descriptions will be omitted. Some block diagrams shown in the accompanying drawings are functional entities and do not necessarily correspond to physically or logically independent entities.

[0051] Technologies, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such technologies, methods, and equipment should be considered part of the description of the present invention.

[0052] In the description of the present invention, it should be understood that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0053] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0054] In a first aspect, the present invention provides a system for simultaneously preparing aromatics and olefins from synthesis gas. Figure 1 The schematic diagram of the system structure for preparing aromatics and olefins from synthesis gas provided by an embodiment of the present invention is shown as follows: Figure 1 As shown, the system for jointly preparing aromatics and olefins from synthesis gas includes: an aromatics synthesis unit 1, an olefins synthesis unit 3, a light olefin conversion unit 6 and a plurality of separation units; the plurality of separation units include a first separation unit 2, a second separation unit 4, and a third separation unit 5; wherein, the aromatics synthesis unit 1, the first separation unit 2, the olefins synthesis unit 3, the second separation unit 4 and the third separation unit 5 are sequentially connected in series, and the second separation unit 4 is connected to the light olefin conversion unit 6.

[0055] See also Figure 1 The aromatics synthesis device 1 is provided with a first transmission pipeline 7 for inputting synthesis gas into the aromatics synthesis device 1 to carry out catalytic conversion reaction of aromatics. The reaction zone of the aromatics synthesis device 1 is filled with a metal oxide-molecular sieve catalyst ( Figure 1 (not shown); the synthesis gas entering the aromatics synthesis unit 1 is catalytically converted into aromatics under the catalytic action of the metal oxide-molecular sieve catalyst to obtain a first mixed gas containing aromatics; since the catalytic conversion of the synthesis gas into aromatics needs to be carried out under high temperature and high pressure conditions (temperature of 250-380°C, pressure of 2.1-6.1 MPa), the reaction pressure is slightly higher than the pressure conditions required for the catalytic conversion of the synthesis gas into olefins. Therefore, the present invention uses the catalytic conversion of the synthesis gas into aromatics as the starting point of the reaction to design the connection relationship between the various devices in the separation and reaction processes in the system, so that this pressure is continuously utilized by the subsequent separation and reaction processes, and the synthesis energy consumption is greatly reduced.

[0056] In some embodiments, the metal oxide in the metal oxide-molecular sieve catalyst can be selected from one or more of zinc oxide, gallium oxide, and germanium oxide; the molecular sieve can be selected from one or more of ZSM-5, ZSM-11, and ZSM-22.

[0057] See also Figure 1The first separation unit 2 is connected in series with the aromatics synthesis unit 1 via a second transmission pipeline 8 to receive the first mixed gas formed by the reaction in the aromatics synthesis unit 1. The first mixed gas is cooled to liquefy the aromatics and water vapor therein, thereby separating it from the other gases. The generated water is discharged from the first separation unit 2 through a first outlet 18, and the liquefied aromatics are discharged from the first separation unit 2 as a product via a third transmission pipeline 17. The remaining gas in the first separation unit 2 is a second mixed gas composed of unreacted synthesis gas, CO2, and a small amount of alkanes.

[0058] In some embodiments, the first separation device 2 is configured to have a first temperature control device with a temperature control range of -20 to 0° C., thereby liquefying aromatic hydrocarbons and water vapor and separating them from other gases.

[0059] In a specific implementation, the reaction zone of the olefin synthesis unit 3 is filled with a catalyst whose active component is a metal carbide. The olefin synthesis unit 3 is connected in series with the first separation unit 2 via a fourth transmission pipeline 9 to receive the remaining second mixed gas in the first separation unit 2. At the same time, a certain amount of fresh synthesis gas is supplied to the olefin synthesis unit 3 via a fifth transmission pipeline 19 provided in the olefin synthesis unit 3. The olefin synthesis unit 3 uses the fresh synthesis gas and the unreacted synthesis gas in the second mixed gas as reaction raw materials to carry out an olefin conversion reaction under the action of the catalyst, thereby obtaining C1-C 10 Since the pressure required for the olefin conversion process is slightly lower than that for the aromatic conversion process, the olefin synthesis unit 3 only needs to adjust the operating temperature to 250-380°C, without the need for an additional pressure control device, and the conversion can be completed by effectively utilizing the pressure of the aromatic conversion process.

[0060] In some embodiments, the metal carbide catalyst may be selected from one or more of iron carbide, cobalt carbide, and nickel carbide.

[0061] In specific implementation, the second separation device 4 is connected in series with the olefin synthesis device 3 through the sixth transmission pipeline 10 to receive the third mixed gas formed by the reaction in the olefin synthesis device 3, and cool the third mixed gas to reduce the temperature of the water vapor and C5-C 10 The hydrocarbons are liquefied and separated, and the remaining fourth mixed gas containing inorganic gases and C1-C4 hydrocarbons; in some embodiments, the second separation device 4 is provided with a second temperature control device having a temperature control range of -60 to -35 ° C to cool the third mixed gas so that the water vapor and C5-C 10 For hydrocarbon liquefaction purposes.

[0062] See also Figure 1 The second separation device 4 is further provided with a seventh transmission pipeline 14 and a second outlet 15. The seventh transmission pipeline 14 is used to transfer the liquefied C5-C 10The hydrocarbons are transferred to the light olefin conversion unit 6 , and the second outlet 15 is used to discharge the liquefied steam from the second separation unit 4 .

[0063] In specific implementation, the third separation device 5 is filled with an adsorbent, and the third separation device 5 is connected in series with the second separation device 4 through the eighth transmission pipeline 11 to receive the fourth mixed gas remaining in the second separation device 4 and adsorb the C2-C4 hydrocarbons therein, leaving the remaining small molecular gases including H2, CO, CO2 and CH4. Figure 1 The third separation device 5 removes the remaining small molecule gases containing H2, CO, CO2, and CH4 from the third separation device 5 through the third outlet 20. The adsorbent adsorbed with C2-C4 hydrocarbons is desorbed and released after decompression and removed from the third separation device 5 through the ninth transmission pipeline 12 for collection.

[0064] It should be noted that the adsorption process performed in the third separation device 5 is a technique for achieving target gas separation based on the adsorption characteristics of the adsorbed object and the spatial confinement of the adsorbent. In this embodiment of the present invention, the third separation device 5 includes a pressure control device and multiple third separation sub-devices arranged in parallel. When the adsorbent in one of the third separation sub-devices reaches saturation, it switches to another third separation sub-device to continue adsorption. The saturated third separation sub-device is then subjected to pressure swing desorption. Specifically, the pressure in the third separation sub-device is controlled to maintain the pressure between 0.06 and 1 MPa, allowing the C2-C4 hydrocarbon gas adsorbed by the adsorbent to be desorbed and released under a lower pressure. After completing pressure swing desorption, the third separation sub-device can be pressure-controlled by the pressure control device (pressurization can be performed as needed to ensure that the pressure in the desorbed third separation sub-device is consistent with the pressure in the eighth transmission pipeline 11) before it can participate in the C2-C4 hydrocarbon gas adsorption process again.

[0065] In some embodiments, the adsorbent filled in the third separation device 5 is selected from inorganic oxides, molecular sieves or carbon, and the pore size of the adsorbent meets the requirement that more than 85% of the pore size is 0.4-0.5 nm.

[0066] In specific implementation, the light olefin conversion unit 6 is filled with pure molecular sieves or metal-molecular sieve catalysts. It should be noted that the metal-molecular sieve catalysts filled are all low-acid catalysts, and the acidity on the catalyst surface is 0.01%-0.1% of the acidity (0.1-1 mmol / g) of hydrogen-type ZSM-5 (silicon-aluminum ratio 120); that is, the acidity of the pure molecular sieve or metal-molecular sieve catalyst is 10 -5 -10 -3mmol / g; specifically, the metal component in the metal-molecular sieve catalyst can be selected from one or more of gallium, zinc, copper and manganese, and the pure molecular sieve or the molecular sieve in the catalyst can be selected from ZSM-5, ZSM-22 or ZSM-11.

[0067] In specific implementation, the liquefied C5-C 10 Hydrocarbons are converted into C2-C4 olefins and a small amount of aromatics under the action of a low-acid catalyst. This conversion needs to be carried out at 450-600°C. In some embodiments, the light olefin conversion unit is provided with a third temperature control device with a temperature control range of 450-600°C to meet the temperature requirements of the light olefin conversion process.

[0068] Continue to see Figure 1 The light olefin conversion unit 6 is provided with a tenth transmission pipeline 13, which can be partially merged with the ninth transmission pipeline 12 to realize the combined collection of the C2-C4 hydrocarbons obtained after analysis by the third separation unit and the C2-C4 olefins generated in the light olefin conversion unit 6; in addition, the light olefin conversion unit 6 is also provided with an eleventh transmission pipeline 16, which can be partially merged with the third transmission pipeline 17 to realize the combined collection of the aromatic hydrocarbons generated in the light olefin conversion unit 6 and the aromatic hydrocarbons obtained by liquefaction in the first separation unit 2.

[0069] The present invention integrates the two production routes of producing aromatics from syngas and producing olefins from syngas. Compared with the construction of a single system for producing aromatics from syngas and a single system for producing olefins from syngas, the construction investment of the integrated system is effectively reduced. In addition, the present invention first produces aromatics from syngas in an aromatics synthesis unit. Since the production of aromatics from syngas needs to be completed under high pressure, this pressure is continuously utilized in the subsequent separation and production of olefins from syngas, which greatly reduces the energy consumption of the synthesis. In addition, the present invention further separates the C5-C 10 It can convert hydrocarbons into C2-C4 olefins and a small amount of aromatics, effectively improving the olefin yield (yield increased by 5-20%) and increasing the proportion of light olefins in the product gas.

[0070] In a second aspect, the present invention provides a method for the simultaneous production of aromatics and olefins from synthesis gas, which is applicable to the system for the simultaneous production of aromatics and olefins from synthesis gas described in the first aspect. First, a metal oxide-molecular sieve catalyst is loaded into the reaction zone of an aromatics synthesis unit, a catalyst whose active component is a metal carbide is loaded into the reaction zone of an olefin synthesis unit, and a molecular sieve or a low-acid metal-molecular sieve-based catalyst is loaded into the reaction zone of a light olefin conversion unit; an adsorbent is loaded into a third separation unit; the operating pressure of the aromatics synthesis unit is controlled to be 2.1-6.1 MPa, and the operating temperature is controlled to be 250-380°C; the operating temperature of the first separation unit is controlled to be -20-0°C; the operating temperature of the olefin synthesis unit is controlled to be 250-380°C; the operating temperature of the second separation unit is controlled to be -60--35°C; and the operating temperature of the light olefin conversion unit is controlled to be 450-600°C; and then the simultaneous production of aromatics and olefins is started. Figure 2 The flow chart of the method for preparing aromatics and olefins from synthesis gas provided by an embodiment of the present invention is shown as follows: Figure 2 As shown, the method includes:

[0071] S1, passing the synthesis gas with an H2 / CO ratio of 1.5:1 to 2.2:1 into an aromatics synthesis unit to convert aromatics to obtain a first mixed gas containing aromatics;

[0072] S2, passing the first mixed gas into a first separation device to liquefy the aromatic hydrocarbons and water vapor in the first mixed gas, and the remaining second mixed gas containing unreacted synthesis gas, CO2 and a small amount of alkanes;

[0073] S3, the second mixed gas is passed into the olefin synthesis unit as the reaction gas, and fresh synthesis gas is further added to carry out olefin conversion reaction to obtain C1-C 10 a third mixed gas of hydrocarbons;

[0074] S4, the third mixed gas is passed into the second separation device, so that the water vapor and C5-C 10 The hydrocarbons are liquefied to leave a fourth mixed gas containing inorganic gases and C1-C4 hydrocarbons;

[0075] S5. Passing the fourth mixed gas into a third separation device, so that the adsorbent in the third separation device adsorbs C2-C4 hydrocarbons in the fourth mixed gas, and the remaining small molecules of gas containing H2, CO, CO2 and CH4;

[0076] S6, the liquefied C5-C 10 The hydrocarbons are fed into the light olefin conversion unit to undergo light olefin conversion reaction to convert C5-C 10 Hydrocarbons are converted into C2-C4 olefins and a small amount of aromatics;

[0077] S7. Combine and collect the C2-C4 olefins generated in the light olefin conversion unit and the C2-C4 hydrocarbons obtained by adsorption in the third separation unit, and combine and collect the aromatics generated in the light olefin conversion unit and the aromatics obtained by liquefaction in the first separation unit.

[0078] In some embodiments, the third separation device may include multiple, parallel third separation sub-devices and pressure control sub-devices, e.g., 2-6. When the adsorbent in one of the third separation sub-devices reaches saturation, the device switches to another third separation sub-device for continued adsorption, and then performs pressure swing desorption on the saturated adsorbent. Specifically, the pressure in the third separation sub-device is maintained at 0.06-1 MPa by manipulating the pressure control sub-device, allowing hydrocarbons with a diameter greater than 0.4 nm (C2-C4 hydrocarbons) adsorbed by the adsorbent to be desorbed and released under a lower pressure. After completing pressure swing desorption, the third separation sub-device can be pressure-controlled by the pressure control device (pressurization can be performed as needed to ensure that the pressure in the desorbed third separation sub-device matches the pressure in the eighth transmission pipeline 11), and then can be used again to adsorb C2-C4 hydrocarbon gas.

[0079] It should be noted that in aromatics synthesis units, the CO single-pass conversion rate is 40-60%, and the aromatics selectivity is 75-90% based on the hydrocarbon base;

[0080] It should also be noted that the volume flow rate of the fresh synthesis gas introduced into the olefin synthesis unit is 3-10 times that of the second mixed gas introduced, so as to facilitate the control of the CO single-pass conversion rate in the olefin synthesis unit to 90-98%; the olefin selectivity is 65%-80% based on the hydrocarbon base, among which the C2-C4 olefin selectivity is 65-85% based on the olefin base.

[0081] In order to enable those skilled in the art to more clearly understand the present invention, the system and method for simultaneously preparing aromatics and olefins from synthesis gas provided by the present invention are now described in detail through the following examples.

[0082] according to Figure 1 The schematic diagram of the system structure for preparing aromatics and olefins by syngas is shown, wherein the aromatics synthesis unit 1, the first separation unit 2, the olefin synthesis unit 3, the second separation unit 4 and the third separation unit 5 are connected in series in sequence, and the second separation unit 4 is connected to the light olefin conversion unit 6, thereby forming a complete system. Figure 1 The system for simultaneously preparing aromatics and olefins from synthesis gas is shown.

[0083] Example 1

[0084] Synthesis gas (with an H2:CO ratio of 1.8:1) is passed through first transmission pipeline 7 to aromatics synthesis unit 1. A metal oxide-molecular sieve catalyst (the oxides are germanium oxide and iron oxide, and the molecular sieve is ZSM-5) is used. The temperature of aromatics synthesis unit 1 is controlled at 250-270°C and the pressure is 3.1 MPa. The syngas is catalytically converted into aromatics, with a CO single-pass conversion rate of 55% and an aromatics selectivity (hydrocarbon radicals) of 83%.

[0085] After the reaction, the first mixed gas containing aromatics (synthesis gas, CO2, water, aromatics, and a small amount of alkanes) obtained by the aromatics synthesis unit 1 enters the first separation unit 2 through the second transmission pipeline 8. At -10°C and 3.05 MPa, the aromatics and water vapor are liquefied and separated from the other gases. The generated water is discharged through the first outlet 18; the liquefied aromatics are discharged as products through the third transmission pipeline 17; the remaining gas is a second mixed gas composed of unreacted synthesis gas, CO2, and a small amount of alkanes, which enters the olefin synthesis unit 3 through the fourth transmission pipeline 9.

[0086] Another stream of fresh syngas (with an H2:CO ratio of 1.7:1 and a flow rate five times the volumetric flow rate of the second mixed gas) is passed through the fifth transmission pipeline 19 to the olefin synthesis unit 3, where the temperature is controlled at 300-320°C and the pressure is maintained at 3 MPa. Olefin conversion is carried out using a catalyst with metal carbides as active sites (99% iron carbide and 1% nickel carbide), producing a third mixed gas containing C1-C9 hydrocarbons. The CO single-pass conversion is 94%, the hydrocarbon products are C1-C9, and the olefin selectivity (hydrocarbon radical) is 78%. The C2-C4 olefin selectivity (hydrocarbon radical) is 78%. The third mixed gas enters the second separation unit 4 via the sixth transmission pipeline 10.

[0087] In the third mixed gas entering the second separation device 4, water and C5-C9 alkanes / olefins are separated as liquid at -50°C and 2.9 MPa, leaving a fourth mixed gas containing inorganic gases and C1-C4 hydrocarbons; the generated water is discharged through the second outlet 15; and the liquefied C5-C9 alkanes / olefins are moved to the light olefin conversion device 6 through the seventh transmission pipeline 14.

[0088] The third separation device 5 is filled with an adsorbent (80% molecular sieve and 20% carbon; more than 85% of the pore size is 0.4-0.5 nm). After the fourth mixed gas enters the third separation device 5 through the eighth transmission pipeline 11, the C2-C4 olefins / alkanes therein are subjected to pressure swing adsorption and separated from other gases (H2, CO, CO2, CH4).

[0089] When the third separation device 5 includes multiple third separation sub-devices arranged in parallel, after one of the third separation sub-devices reaches saturation through adsorption, the third transmission pipeline 11 is controlled to flow into another first separation device for continued adsorption, and the saturated third separation sub-device is subjected to desorption. Specifically, the pressure within the saturated third separation sub-device is controlled to 0.1 MPa, and the C2 and higher hydrocarbons desorbed under reduced pressure exit the third separation device 5 through the ninth transmission pipeline 12 for collection. Other small molecule gases (H2, CO, CO2, CH4) exit the third separation device 5 through the third outlet 20. After desorption, the third separation sub-device can be pressure-controlled (pressurized as needed to ensure that the pressure in the third separation sub-device after desorption is consistent with the pressure in the eighth transmission pipeline 11) and then participate in the adsorption of C2-C4 hydrocarbon gases again.

[0090] The C5-C9 alkanes / olefins transferred to the light olefin conversion unit 6 were heated on a low acid content metal-molecular sieve based catalyst (metal: 0.001% gallium, 0.002% zinc, 0.003% copper, 0.004% manganese. The molecular sieve was ZSM-5; the acid content on the catalyst surface was 5*10 -4 mmol / g (which is 0.05% of the acid amount of hydrogen ZSM-5 (silicon-aluminum ratio of 120, acid amount of 1 mmol / g)) and at 480-520°C, C5-C9 olefins / alkanes are converted into C2-C4 olefins and a small amount of aromatics. After the products are cooled, the olefin products are collected through the tenth transmission pipeline 13 and combined with the logistics of the ninth transmission pipeline 12; the aromatic products are collected through the eleventh transmission pipeline 16 and combined with the logistics of the third transmission pipeline 17.

[0091] Example 2

[0092] Synthesis gas (H2:CO ratio of 2:1) is introduced into the aromatics synthesis unit 1 through the first transmission pipeline 7, using a catalyst with a metal oxide-molecular sieve active site (the oxide is zinc oxide and the molecular sieve is ZSM-5). The temperature of the aromatics synthesis unit 1 is controlled at 300-330°C and the pressure is controlled at 4.1 MPa to catalytically convert the synthesis gas into aromatics, wherein the CO single-pass conversion rate is 50% and the aromatics selectivity (hydrocarbon radical) is 80%.

[0093] After the reaction, the first mixed gas containing aromatics (synthesis gas, CO2, water, aromatics, and a small amount of alkanes) obtained by the aromatics synthesis unit 1 enters the first separation unit 2 through the second transmission pipeline 8. At -10°C and 4.05 MPa, the aromatics and water vapor are liquefied and separated from the other gases. The generated water is discharged through the first outlet 18; the liquefied aromatics are discharged as products through the third transmission pipeline 17; the remaining gas is a second mixed gas composed of unreacted synthesis gas, CO2, and a small amount of alkanes, which enters the olefin synthesis unit 3 through the fourth transmission pipeline 9.

[0094] Another stream of fresh syngas (with an H2:CO ratio of 1.8:1 and a flow rate five times the volumetric flow rate of the second mixed gas) is passed through the fifth transmission pipeline 19 to the olefin synthesis unit 3, where the temperature is controlled at 350-360°C and the pressure is maintained at 4 MPa. Olefin conversion is carried out using a catalyst with a metal carbide active site (the metal carbide being iron carbide), producing a third mixed gas containing C1-C8 hydrocarbons. The CO single-pass conversion is 95%, the hydrocarbon products are C1-C8, and the olefin selectivity (hydrocarbon radicals) is 74%. The C2-C4 olefin selectivity (hydrocarbon radicals) is 75%. The third mixed gas enters the second separation unit 4 via the sixth transmission pipeline 10.

[0095] In the third mixed gas entering the second separation device 4, water and C5-C8 alkanes / olefins are separated as liquid at -45°C and 3.9 MPa, leaving a fourth mixed gas containing inorganic gases and C1-C4 hydrocarbons; the generated water is discharged through the second outlet 15; and the liquefied C5-C8 alkanes / olefins are moved to the light olefin conversion device 6 through the seventh transmission pipeline 14.

[0096] The third separation device 5 is filled with an adsorbent (90% inorganic oxide and 10% molecular sieve; more than 85% of the adsorbent has a pore size of 0.4-0.5 nm). After the fourth mixed gas enters the third separation device 5 through the eighth transmission pipeline 11, the C2-C4 olefins / alkanes therein are pressure-swing adsorbed and separated from other gases (H2, CO, CO2, CH4).

[0097] When the third separation device 5 includes multiple third separation sub-devices arranged in parallel, after one of the third separation sub-devices reaches saturation through adsorption, the third transmission pipeline 11 is controlled to flow into another first separation device for continued adsorption, and the saturated third separation sub-device is subjected to desorption. Specifically, the pressure within the saturated third separation sub-device is controlled to 0.4 MPa, and the C2 and higher hydrocarbons desorbed under reduced pressure exit the third separation device 5 through the ninth transmission pipeline 12 for collection. Other small molecule gases (H2, CO, CO2, CH4) exit the third separation device 5 through the third outlet 20. After desorption, the third separation sub-device can be pressure-controlled (pressurized as needed to ensure that the pressure in the third separation sub-device after desorption is consistent with the pressure in the eighth transmission pipeline 11) and then participate in the adsorption of C2-C4 hydrocarbon gases again.

[0098] The C5-C8 alkanes / olefins transferred to the light olefin conversion unit 6 are heated on a metal-molecular sieve-based catalyst with a low acid content (the metal is 0.05% gallium, 0.008% manganese. The molecular sieve is 90% ZSM-5, 10% ZSM-11; the acid content on the catalyst surface is 10 -3mmol / g (0.1% of the acid amount of hydrogen ZSM-5 (silicon-aluminum ratio 120, acid amount 1 mmol / g)), and at 550-560°C, C5-C8 olefins / alkanes are converted into C2-C4 olefins and a small amount of aromatics. After the product is cooled, the obtained olefin product is collected through the tenth transmission pipeline 13 and combined with the logistics of the ninth transmission pipeline 12; the aromatic product is collected through the eleventh transmission pipeline 16 and combined with the logistics of the third transmission pipeline 17.

[0099] Example 3

[0100] Synthesis gas (with an H2:CO ratio of 1.5:1) is passed through first transmission pipeline 7 to aromatics synthesis unit 1. A metal oxide-molecular sieve catalyst (germanium oxide as the oxide and ZSM-5 as the molecular sieve) with active sites is used. The temperature of aromatics synthesis unit 1 is controlled at 250-280°C and the pressure is maintained at 2.1 MPa. The syngas is catalytically converted into aromatics, achieving a CO single-pass conversion rate of 40% and an aromatics selectivity (hydrocarbon radicals) of 75%.

[0101] After the reaction, the first mixed gas containing aromatics (synthesis gas, CO2, water, aromatics, and a small amount of alkanes) obtained by the aromatics synthesis unit 1 enters the first separation unit 2 through the second transmission pipeline 8. At -20°C and 2.05 MPa, the aromatics and water vapor are liquefied and separated from the other gases. The generated water is discharged through the first outlet 18; the liquefied aromatics are discharged as products through the third transmission pipeline 17; the remaining gas is a second mixed gas composed of unreacted synthesis gas, CO2, and a small amount of alkanes, which enters the olefin synthesis unit 3 through the fourth transmission pipeline 9.

[0102] Another stream of fresh syngas (with an H2:CO ratio of 2.2:1 and a flow rate three times the volumetric flow rate of the second mixed gas) is passed through the fifth transmission pipeline 19 to the olefin synthesis unit 3, where the temperature is controlled at 320-350°C and the pressure is maintained at 2 MPa. Olefin conversion is carried out using a catalyst with metal carbides as active sites (20% cobalt carbide and 80% iron carbide), producing a third mixed gas containing C1-C7 hydrocarbons. The CO single-pass conversion rate is 90%, and the hydrocarbon products are C1-C7. The olefin selectivity (hydrocarbon radicals) is 65%, and the C2-C4 olefin (hydrocarbon radicals) selectivity is 85%. The third mixed gas enters the second separation unit 4 via the sixth transmission pipeline 10.

[0103] In the third mixed gas entering the second separation device 4, water and C5-C7 alkanes / olefins are separated as liquid at -60°C and 2 MPa, leaving a fourth mixed gas containing inorganic gases and C1-C4 hydrocarbons; the generated water is discharged through the second outlet 15; and the liquefied C5-C7 alkanes / olefins are moved to the light olefin conversion device 6 through the seventh transmission pipeline 14.

[0104] The third separation device 5 is filled with an adsorbent (20% molecular sieve, 80% carbon; more than 85% of the pore size is 0.4-0.5 nm). After the fourth mixed gas enters the third separation device 5 through the eighth transmission pipeline 11, the C2-C4 olefins / alkanes therein are subjected to pressure swing adsorption and separated from other gases (H2, CO, CO2, CH4).

[0105] When the third separation device 5 includes multiple third separation sub-devices arranged in parallel, after one of the third separation sub-devices reaches saturation through adsorption, the third transmission pipeline 11 is controlled to flow into another first separation device for continued adsorption, and the saturated third separation sub-device is subjected to desorption. Specifically, the pressure within the saturated third separation sub-device is regulated to 0.08 MPa, and the C2 and higher hydrocarbons desorbed under reduced pressure exit the third separation device 5 through the ninth transmission pipeline 12 for collection. Other small molecule gases (H2, CO, CO2, CH4) exit the third separation device 5 through the third outlet 20. After desorption, the third separation sub-device can be pressure-controlled (pressurized as needed to ensure that the pressure in the third separation sub-device after desorption is consistent with the pressure in the eighth transmission pipeline 11) and then participate in the adsorption of C2-C4 hydrocarbon gases again.

[0106] The C5-C7 alkanes / olefins transferred to the light olefin conversion unit 6 are heated on a metal-molecular sieve-based catalyst with a low acid content (the metal is 0.05% zinc, 0.05% copper. The molecular sieve is 5% ZSM-22, 95% ZSM-11; the acid content of the catalyst surface is 10 -5 mmol / g (which is 0.01% of the acid amount of hydrogen ZSM-5 (silicon-aluminum ratio of 120, acid amount of 0.1 mmol / g)), and at 450-480°C, C5-C7 olefins / alkanes are converted into C2-C4 olefins and a small amount of aromatics. After the product is cooled, the obtained olefin product is collected through the tenth transmission pipeline 13 and combined with the logistics of the ninth transmission pipeline 12; the aromatic hydrocarbon product is collected through the eleventh transmission pipeline 16 and combined with the logistics of the third transmission pipeline 17.

[0107] Example 4

[0108] Synthesis gas (with an H2:CO ratio of 2.2:1) is passed through first transmission pipeline 7 to aromatics synthesis unit 1. A metal oxide-molecular sieve catalyst (gallium oxide as the oxide, ZSM-11 as the molecular sieve) is used. The temperature of aromatics synthesis unit 1 is controlled at 350-380°C and the pressure is 6.1 MPa. The syngas is catalytically converted into aromatics, with a CO single-pass conversion rate of 60% and an aromatics selectivity (hydrocarbon radicals) of 90%.

[0109] After the reaction, the first mixed gas containing aromatics (synthesis gas, CO2, water, aromatics, and a small amount of alkanes) obtained by the aromatics synthesis unit 1 enters the first separation unit 2 through the second transmission pipeline 8. At 0°C and 6.05 MPa, the aromatics and water vapor are liquefied and separated from other gases. The generated water is discharged through the first outlet 18; the liquefied aromatics are discharged as products through the third transmission pipeline 17; the remaining gas is a second mixed gas composed of unreacted synthesis gas, CO2, and a small amount of alkanes, which enters the olefin synthesis unit 3 through the fourth transmission pipeline 9.

[0110] Another stream of fresh synthesis gas (with a ratio of H2 to CO of 1.5:1 and a flow rate 10 times the volume flow rate of the second mixed gas) is introduced into the olefin synthesis unit 3 from the fifth transmission pipeline 19, with the temperature controlled at 350°C and the pressure at 6 MPa. Using a catalyst with metal carbides as active sites (the metal carbides are 70% iron carbide, 10% cobalt carbide, and 20% nickel carbide), olefin conversion reaction is carried out to obtain C1-C 10 The third mixed gas of hydrocarbons, in which the CO single-pass conversion rate is 98%, and the hydrocarbon products are C1-C 10 The olefin selectivity (hydrocarbon radical) is 80%. The C2-C4 olefin (olefin radical) is 65%. The third mixed gas enters the second separation device 4 through the sixth transmission pipeline 10.

[0111] The third mixed gas entering the second separation device 4 is heated to -35°C and 5.9 MPa, and the water and C5-C 10 The alkane / olefin is separated as liquid, and the remaining fourth mixed gas containing inorganic gas and C1-C4 hydrocarbons; wherein the generated water is discharged through the second outlet 15; the liquefied C5-C 10 The alkanes / olefins are moved to the light olefin conversion unit 6 through the seventh transfer line 14 .

[0112] The third separation device 5 is filled with an adsorbent (carbon; more than 85% of the pore size is 0.4-0.5 nm). After the fourth mixed gas enters the third separation device 5 through the eighth transmission pipeline 11, the C2-C4 olefins / alkanes therein are subjected to pressure swing adsorption and separated from other gases (H2, CO, CO2, CH4).

[0113] When the third separation device 5 includes multiple third separation sub-devices arranged in parallel, after one third separation sub-device is saturated with adsorption, the third transmission pipeline 11 is controlled to flow into another first separation device for continued adsorption, and the saturated third separation sub-device is subjected to desorption. Specifically, the pressure within the saturated third separation sub-device is controlled to 1 MPa, and the C2 and higher hydrocarbons desorbed under reduced pressure exit the third separation device 5 through the ninth transmission pipeline 12 for collection. Other small molecule gases (H2, CO, CO2, CH4) exit the third separation device 5 through the third outlet 20. After desorption, the third separation sub-device can be pressure-controlled (pressurized as needed to ensure that the pressure in the third separation sub-device after desorption is consistent with the pressure in the eighth transmission pipeline 11) and then participate in the adsorption of C2-C4 hydrocarbon gases again.

[0114] C5-C 10 Alkanes / olefins are synthesized on metal-molecular sieve-based catalysts with low acid content (the metal is gallium with a content of 0.001%. The molecular sieves are 45% ZSM-5, 35% ZSM-11, and 20% ZSM-22; the acid content on the catalyst surface is 10 -4 mmol / g (0.01% of the acid content of hydrogen ZSM-5 (Si-Al ratio 120, acid content 1 mmol / g)), and at 600 °C, C5-C 10 Olefins / alkanes are converted into C2-C4 olefins and a small amount of aromatics. After the product is cooled, the obtained olefin products are collected through the tenth transmission pipeline 13 and combined with the logistics of the ninth transmission pipeline 12; the aromatic products are collected through the eleventh transmission pipeline 16 and combined with the logistics of the third transmission pipeline 17.

[0115] Example 5

[0116] Synthesis gas (with an H2:CO ratio of 1.9:1) was passed through first transmission pipeline 7 to aromatics synthesis unit 1. A metal oxide-molecular sieve catalyst (germanium oxide as the oxide and ZSM-5 as the molecular sieve) was used. The temperature of aromatics synthesis unit 1 was controlled at 270-290°C and the pressure at 5.1 MPa. The syngas was catalytically converted into aromatics, achieving a CO single-pass conversion rate of 49% and an aromatics selectivity (hydrocarbon radicals) of 78%.

[0117] After the reaction, the first mixed gas containing aromatics (synthesis gas, CO2, water, aromatics, and a small amount of alkanes) obtained by the aromatics synthesis unit 1 enters the first separation unit 2 through the second transmission pipeline 8. At -10°C and 5.05 MPa, the aromatics and water vapor are liquefied and separated from the other gases. The generated water is discharged through the first outlet 18; the liquefied aromatics are discharged as products through the third transmission pipeline 17; the remaining gas is a second mixed gas composed of unreacted synthesis gas, CO2, and a small amount of alkanes, which enters the olefin synthesis unit 3 through the fourth transmission pipeline 9.

[0118] Another stream of fresh synthesis gas (with a ratio of H2 to CO of 1.9:1 and a flow rate six times the volume flow rate of the second mixed gas) is introduced into the olefin synthesis unit 3 from the fifth transmission pipeline 19, with the temperature controlled at 330-346°C and the pressure at 5 MPa. Using a catalyst with metal carbide as the active site (the metal carbide is 10% cobalt carbide and 90% iron carbide), olefin conversion reaction is carried out to obtain C1-C 10 The third mixed gas of hydrocarbons, in which the CO single-pass conversion rate is 92%, and the hydrocarbon products are C1-C 10 The olefin selectivity (hydrocarbon radical) was 79%. The C2-C4 olefin (olefin radical) was 81.4%. The third mixed gas entered the second separation device 4 via the sixth transmission pipeline 10.

[0119] The third mixed gas entering the second separation device 4 is heated to -50°C and 4.8 MPa, and the water and C5-C 10 The alkane / olefin is separated as liquid, and the remaining fourth mixed gas containing inorganic gas and C1-C4 hydrocarbons; wherein the generated water is discharged through the second outlet 15; the liquefied C5-C 10 The alkanes / olefins are moved to the light olefin conversion unit 6 through the seventh transfer line 14 .

[0120] The third separation device 5 is filled with an adsorbent (molecular sieve; more than 85% of the pore size is 0.4-0.5 nm). After the fourth mixed gas enters the third separation device 5 through the eighth transmission pipeline 11, the C2-C4 olefins / alkanes therein are subjected to pressure swing adsorption and separated from other gases (H2, CO, CO2, CH4).

[0121] When the third separation device 5 includes multiple third separation sub-devices arranged in parallel, after one of the third separation sub-devices reaches saturation through adsorption, the third transmission pipeline 11 is controlled to flow into another first separation device for continued adsorption, and the saturated third separation sub-device is subjected to desorption. Specifically, the pressure within the saturated third separation sub-device is controlled to 0.2 MPa, and the C2 and higher hydrocarbons desorbed under reduced pressure exit the third separation device 5 through the ninth transmission pipeline 12 for collection. Other small molecule gases (H2, CO, CO2, CH4) exit the third separation device 5 through the third outlet 20. After desorption, the third separation sub-device can be pressure-controlled (pressurized as needed to ensure that the pressure in the third separation sub-device after desorption is consistent with the pressure in the eighth transmission pipeline 11) and then participate in the adsorption of C2-C4 hydrocarbon gases again.

[0122] C5-C 10 Alkanes / olefins are reacted with molecular sieves (5% ZSM-22, 95% ZSM-5) at 550-580℃, C5-C 10 Olefins / alkanes are converted into C2-C4 olefins and a small amount of aromatics. After the product is cooled, the obtained olefin products are collected through the tenth transmission pipeline 13 and combined with the logistics of the ninth transmission pipeline 12; the aromatic products are collected through the eleventh transmission pipeline 16 and combined with the logistics of the third transmission pipeline 17.

[0123] In the description of this specification, the reference terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification.

[0124] For simplicity of description, the method embodiments are described as a series of actions. However, those skilled in the art should be aware that the present invention is not limited by the order of the actions described, as certain steps can be performed in other orders or simultaneously according to the present invention. Furthermore, those skilled in the art should also be aware that the embodiments described in this specification are preferred embodiments, and the actions and components involved are not necessarily required for the present invention.

[0125] The above is a detailed introduction to the system and method for the joint preparation of aromatics and olefins from synthesis gas provided by the present invention. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core concept. At the same time, for those skilled in the art, according to the concept of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present invention.

Claims

1. A system for simultaneously preparing aromatics and olefins from synthesis gas, characterized in that: include: Aromatics synthesis unit, olefin synthesis unit, light olefin conversion unit and multiple separation units; among which, The aromatics synthesis unit, the first separation unit, the olefin synthesis unit, the second separation unit and the third separation unit are sequentially connected in series, and the second separation unit is connected to the light olefin conversion unit; The aromatics synthesis device is used to catalytically convert synthesis gas into aromatics to obtain a first mixed gas containing aromatics; The first separation device is used to receive and cool the first mixed gas to liquefy the aromatic hydrocarbons and water vapor therein, and the remaining second mixed gas consists of unreacted synthesis gas, CO2 and a small amount of alkanes; The olefin synthesis device is used to receive the second mixed gas and fresh synthesis gas, and perform olefin conversion reaction to obtain C1-C 10 a third mixed gas of hydrocarbons; The second separation device is used to receive and cool the third mixed gas, so that the water vapor and C5-C 10 The hydrocarbons are liquefied to leave a fourth mixed gas containing inorganic gases and C1-C4 hydrocarbons; The third separation device is used to receive the fourth mixed gas and perform adsorption to separate C2-C4 hydrocarbons from small molecule gases H2, CO, CO2 and CH4; The light olefin conversion unit is used to receive the liquefied C5-C 10 hydrocarbons and convert them into C2-C4 olefins and a small amount of aromatics.

2. The system for simultaneously preparing aromatics and olefins from synthesis gas according to claim 1, characterized in that: The aromatics synthesis device is filled with a metal oxide-molecular sieve catalyst; wherein, The metal oxide includes one or more of zinc oxide, gallium oxide and germanium oxide; Molecular sieves include: one or more of ZSM-5, ZSM-11, and ZSM-22; The aromatics synthesis unit has an operating temperature of 250-380°C and an operating pressure of 2.1-6.1 MPa.

3. The system for simultaneously preparing aromatics and olefins from synthesis gas according to claim 1, characterized in that: The first separation device is provided with a first temperature control device to cool the first mixed gas to liquefy the aromatic hydrocarbons and water vapor therein; wherein, The temperature control range of the first temperature control device includes -20~0℃.

4. The system for simultaneously preparing aromatics and olefins from synthesis gas according to claim 1, characterized in that: The olefin synthesis device is filled with a catalyst whose active component is a metal carbide; wherein the metal carbide includes one or more of iron carbide, cobalt carbide and nickel carbide; The operating temperature of the olefin synthesis unit is 250-380°C.

5. The system for simultaneously preparing aromatics and olefins from synthesis gas according to claim 1, characterized in that: The second separation device is provided with a second temperature control device to cool the third mixed gas so that the H2O, C5-C 10 The purpose of hydrocarbon liquefaction; wherein, The temperature control range of the second temperature control device includes -60~-35℃.

6. The system for simultaneously preparing aromatics and olefins from synthesis gas according to claim 1, characterized in that: The third separation device includes a pressure sub-control device and a plurality of third separation sub-devices arranged in parallel, and the plurality of third separation sub-devices are filled with adsorbent; wherein, The adsorbent is an inorganic oxide, a molecular sieve or carbon, and the pore size of the adsorbent meets the requirement that more than 85% of the pore size is 0.4-0.5 nm.

7. The system for simultaneously preparing aromatics and olefins from synthesis gas according to claim 1, characterized in that: The light olefin conversion unit is filled with a molecular sieve or a metal-molecular sieve-based catalyst; wherein the metal is one or more of gallium, zinc, copper and manganese, and the molecular sieve is ZSM-5, ZSM-22 or ZSM-11; The acid amount of the molecular sieve and the metal-molecular sieve based catalyst is 10 -5 -10 -3 mmol / g; The light olefin conversion unit is provided with a third temperature control device, and the temperature control range of the third temperature control device includes 450-600°C.

8. A method for simultaneously preparing aromatics and olefins from synthesis gas, characterized in that: The method is applicable to the system for simultaneously preparing aromatics and olefins from synthesis gas as described in any one of claims 1 to 7, and the method comprises: The reaction zone of the aromatics synthesis unit is filled with a metal oxide-molecular sieve catalyst, the reaction zone of the olefin synthesis unit is filled with a catalyst whose active component is a metal carbide, and the reaction zone of the light olefin conversion unit is filled with a molecular sieve or a metal-molecular sieve-based catalyst; and the third separation unit is filled with an adsorbent; Controlling the operating pressure of the aromatics synthesis unit to 2.1-6.1 MPa and the operating temperature to 250-380°C, controlling the operating temperature of the first separation unit to -20-0°C, controlling the operating temperature of the olefin synthesis unit to 250-380°C, controlling the operating temperature of the second separation unit to -60--35°C, and controlling the operating temperature of the light olefin conversion unit to 450-600°C; Passing synthesis gas with a H2 / CO ratio of 1.5:1 to 2.2:1 into the aromatics synthesis unit to convert aromatics to obtain a first mixed gas containing aromatics; Passing the first mixed gas into the first separation device to liquefy the aromatic hydrocarbons and water vapor in the first mixed gas, and leaving a second mixed gas composed of unreacted synthesis gas, CO2 and a small amount of alkanes; The second mixed gas is introduced into the olefin synthesis unit as the reaction gas, and fresh synthesis gas is further added to carry out olefin conversion reaction to obtain C1-C 10 a third mixed gas of hydrocarbons; The third mixed gas is passed into the second separation device, so that the water vapor and C5-C 10 The hydrocarbons are liquefied to leave a fourth mixed gas containing inorganic gases and C1-C4 hydrocarbons; Passing the fourth mixed gas into a third separation device so that the adsorbent in the third separation device adsorbs C2-C4 hydrocarbons in the fourth mixed gas, and the remaining small molecular gases include H2, CO, CO2 and CH4; The liquefied C5-C 10 The hydrocarbons are fed into the light olefin conversion unit to undergo light olefin conversion reaction to obtain C5-C 10 Hydrocarbons are converted into C2-C4 olefins and a small amount of aromatics; The C2-C4 olefins generated in the light olefin conversion unit and the C2-C4 hydrocarbons obtained by adsorption in the third separation unit are combined and collected, and the aromatics generated in the light olefin conversion unit and the aromatics obtained by liquefaction in the first separation unit are combined and collected.

9. The method for simultaneously preparing aromatics and olefins from synthesis gas according to claim 8, characterized in that: In the olefin synthesis device, the volume flow rate of the introduced fresh synthesis gas is 3-10 times that of the introduced second mixed gas.

10. The method for simultaneously preparing aromatics and olefins from synthesis gas according to claim 8, characterized in that: In the aromatics synthesis unit, the CO single-pass conversion rate is 40-60%, and the aromatics selectivity is 75-90% based on the hydrocarbon base; In the olefin synthesis device, the CO single-pass conversion rate is 90-98%; Based on the hydrocarbon group, the olefin selectivity is 65%-80%, among which, based on the olefin group, the C2-C4 olefin selectivity is 65-85%.

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