Washing method of crude synthesis gas

Abstract

The invention relates to a washing method of crude synthesis gas, which comprises the following steps: feeding the crude synthesis gas into a primary washer for primary washing, and then feeding the obtained first crude synthesis gas into a separation tank for separation to obtain tank top synthesis gas and tank bottom liquid containing solid particles; the synthesis gas at the top of the separation tank is fed into a secondary scrubber for secondary washing, and then the obtained second crude synthesis gas is fed into a scrubber tower for third washing, so that purified synthesis gas is obtained at the top of the scrubber tower, and a liquid material is obtained at the bottom of the scrubber tower; the efficient gas-liquid separation internal component comprises one of a gas-liquid rotational flow internal component, a cyclone separator and a herringbone tower tray internal component. The method is good in washing and purifying effect on the synthesis gas, the content of solid particles in the washed and purified synthesis gas is low, meanwhile, the system is simple, the process is short, the method has the advantages of low energy consumption, low water consumption and the like, reasonable utilization of resources can be achieved, adopted devices are not prone to being blocked and abraded, and the method is suitable for the purification process of large-scale synthesis gas production through carbonaceous substance gasification.

Description

Technical Field

[0001] The present disclosure relates to the technical field of gas purification, and in particular to a method for washing raw synthesis gas. Background Art

[0002] As energy demand continues to grow and fossil fuels become increasingly depleted, the efficient and clean utilization of every chemical molecule in energy has become a hot topic in current energy research. Gasifying fossil fuels such as coal and petroleum (petroleum coke, residual oil, oil residue, and asphalt) to produce syngas offers the greatest potential for efficient and clean utilization. This syngas can then be processed into chemical products or clean energy, such as olefins, methanol, urea, and hydrogen, to meet diverse societal needs.

[0003] Pressurized entrained flow gasification technology is internationally recognized as one of the most advanced gasification technologies. The gasification feedstock is primarily in powder or slurry form, and requires a gasifying agent as a transport medium to deliver it to the gasifier. After nozzle atomization, the feedstock is thoroughly mixed with the gasifier, undergoing intense pyrolysis, combustion, and gasification reactions, resulting in a crude syngas composed primarily of carbon monoxide and hydrogen, along with a small amount of solid slag. Common examples of pressurized entrained flow gasification technology include Texaco, Shell, and Huali's multi-nozzle furnaces. Currently, little research has been conducted on the purification of the syngas produced by gasifiers, with traditional cooling and washing methods often employed. The crude syngas produced by different gasifiers and gasification feedstocks exhibits significant variations in temperature, pressure, and solid particle content. For example, the crude syngas produced by coal gasification uses a cyclone separator to separate solid particles, which results in significant equipment wear and poor separation of fine particles. The temperature of biomass gasification synthesis gas is relatively high and contains a small amount of tar. It is usually cooled by a water-cooled quenching tower with water spraying and waste heat recovery by a heat pipe preheating furnace. However, it has the disadvantages of narrow application range and low operational flexibility.

[0004] In the existing technology, the purification of gasification synthesis gas has the disadvantages of complex system, long process, poor gas-solid separation effect, easy clogging, low efficiency, easy wear and high energy consumption. Summary of the Invention

[0005] The purpose of the present disclosure is to provide a method for washing crude synthesis gas, which has a good washing and purification effect on the synthesis gas, and the solid particle content in the synthesis gas after washing and purification is low. At the same time, the method has a simple system, a short process, and has the advantages of low energy consumption and low water consumption.

[0006] In order to achieve the above object, the present disclosure provides a method for scrubbing raw synthesis gas, the method comprising the following steps:

[0007] The crude synthesis gas is sent to a primary scrubber for a first scrubbing, and the obtained first crude synthesis gas is then sent to a separation tank for separation to obtain synthesis gas at the top of the tank and liquid containing solid particles at the bottom of the tank; the synthesis gas at the top of the tank is sent to a secondary scrubber for a second scrubbing, and the obtained second crude synthesis gas is then sent to a scrubber for a third scrubbing, and purified synthesis gas is obtained at the top of the scrubber and liquid material is obtained at the bottom of the scrubber; wherein, the separation tank is provided with high-efficiency gas-liquid separation internals; the high-efficiency gas-liquid separation internals include one of gas-liquid cyclone internals, cyclone separators and herringbone tray internals.

[0008] Optionally, the method further includes injecting a washing liquid into the separation tank, the injection amount being 1 wt% to 40 wt% of the injection amount of the crude synthesis gas; the washing liquid is selected from at least one of conversion condensate, high-pressure ash water, desalted water, deoxygenated water and fresh water; the temperature of the washing liquid is 100°C to 450°C; the separation tank is selected from at least one of a vertical separation tank and a horizontal separation tank, preferably a vertical separation tank.

[0009] Optionally, the primary scrubber and the secondary scrubber are each independently selected from one or more of a venturi scrubber, a venturi scrubber tower and a mixer;

[0010] Washing water is respectively injected into the primary scrubber and the secondary scrubber, and the washing water comprises one or more of shift condensate, high-pressure ash water, desalted water, deoxygenated water and fresh water; the temperature of the washing water is 100°C to 450°C, and the pressure is 0.5MPa to 10MPa; the total amount of washing water injected into the primary scrubber and the secondary scrubber is each independently 5wt% to 20wt% of the injection amount of the crude synthesis gas.

[0011] Optionally, the first-stage scrubber and the second-stage scrubber are respectively venturi scrubbers; the venturi scrubber includes a contraction tube, a throat tube and an expansion tube; the flow cross-sectional area of ​​the throat tube is 5%-35% of the cross-sectional area of ​​the contraction tube orifice, and the flow cross-sectional area of ​​the throat tube is 3%-30% of the cross-sectional area of ​​the expansion tube orifice.

[0012] Optionally, the temperature of the crude synthesis gas is 200°C to 450°C, and the particle content is 10g / Nm 3 ~100g / Nm 3 , the pressure is 0.5MPa~10MPa, preferably, the temperature of the crude synthesis gas is 150℃~350℃, and the particle content is 20g / Nm 3 ~90g / Nm 3 , pressure is 1.0MPa~6.5MPa;

[0013] The raw synthesis gas includes one or more of coal gasifier synthesis gas, heavy oil gasifier synthesis gas, coal-oil co-gasifier synthesis gas, biomass gasifier synthesis gas and solid waste gasifier synthesis gas.

[0014] Optionally, the method further comprises sending the liquid containing solid particles at the bottom of the tank to a downstream facility or a scrubbing tower.

[0015] Optionally, the liquid material is processed by one or more of sending it to a downstream device for separation of solid particles, sending it to a gasification furnace as quenching water, and circulating it into a scrubbing tower.

[0016] Optionally, at least one of a tray and a packing is provided in the scrubbing tower, and the tray is a herringbone tray;

[0017] At least one washing liquid is injected into the scrubber, and the washing liquid is selected from one or more of shift condensate, high-pressure ash water, desalted water, deoxygenated water, and fresh water; the inlet temperature of the washing liquid is 100° C. to 450° C., the pressure is 0.5 MPaG to 10 MPaG, and the injection amount is 5 wt% to 155 wt% of the injection amount of the crude synthesis gas;

[0018] The solid particle content in the purified synthesis gas is less than 5 mg / Nm 3 .

[0019] Optionally, the solid particle content in the purified synthesis gas is 0.1 mg / Nm 3 ~5mg / Nm 3 .

[0020] Optionally, the bottoms of the separation tank and the scrubber tower independently adopt one of a circular head, an elliptical head and a conical head, preferably a conical head; the cone angle of the conical head is 30° to 85°.

[0021] Through the above-mentioned technical solution, the crude syngas scrubbing method provided herein performs a first scrubbing and gas-solid separation on the crude syngas, then performs a second scrubbing on the tank top syngas after the first scrubbing, and performs a third scrubbing in a scrubber, further removing small amounts of solid particles carried in the syngas and capturing particles in the syngas, thereby achieving the goal of reducing and purifying solid particles in the syngas. This method has excellent scrubbing and purification effects on syngas, especially syngas from a gasifier, resulting in a low solid particle content in the syngas after scrubbing and purification. Furthermore, this method has the advantages of a simple system, a short process flow, low energy consumption, and low water consumption, thus achieving rational resource utilization. The devices used in this method are not easily clogged or worn, making it suitable for the purification process of large-scale carbon-containing gasification syngas production.

[0022] Other features and advantages of the present disclosure will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following detailed description, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0024] Figure 1 This is a schematic diagram of the process of washing the raw synthesis gas in Example 1 of the present disclosure.

[0025] Figure 2 Schematic diagram of crude synthesis gas washing in Example 2 of the present disclosure.

[0026] Figure 3 Schematic diagram of crude synthesis gas washing in Example 3 of the present disclosure.

[0027] Figure 4 Schematic diagram of the venturi scrubber used in the embodiment of the present disclosure.

[0028] Figure 5 Schematic diagram of crude synthesis gas washing in Comparative Example 1 of the present disclosure.

[0029] Description of Reference Numerals

[0030] 101: Crude synthesis gas, 102: First crude synthesis gas, 103: Liquid containing solid particles at the bottom of the tank, 104: Synthesis gas at the top of the tank, 105: Second crude synthesis gas, 106: Purified synthesis gas, 107: Scrubbing liquid, 108: Scrubbing liquid, 109: Flushing scrubbing liquid, 110: Scrubbing tower bottom liquid, 111: Circulating scrubbing tower bottom liquid, 112: Pumping scrubbing tower bottom liquid, 113: Sending scrubbing tower bottom liquid to the outside,

[0031] S-101: primary scrubber, S-102: secondary scrubber, S-103: primary static mixer, S-104: secondary static mixer, D-101: separation tank, C-101: scrubber, P-101: scrubber bottom pump, a1: synthesis gas inlet, a2: scrubbing liquid inlet, a3: synthesis gas outlet. DETAILED DESCRIPTION

[0032] The following describes the specific embodiments of the present disclosure in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present disclosure and are not intended to limit the present disclosure.

[0033] like Figure 1 As shown, the present disclosure provides a method for scrubbing raw synthesis gas, the method comprising the following steps:

[0034] The crude synthesis gas 101 is sent to the first-stage scrubber S-101 for the first scrubbing, and then the obtained first crude synthesis gas 102 is sent to the separation tank D-101 for separation to obtain the tank top synthesis gas 104 and the tank bottom liquid containing solid particles 103; the tank top synthesis gas 104 is sent to the second-stage scrubber S-102 for the second scrubbing, and then the obtained second crude synthesis gas 105 is sent to the scrubber C-101 for the third scrubbing, and the top of the scrubber obtains the purified synthesis gas 106, and the bottom of the scrubber obtains the liquid material; wherein, the separation tank is provided with a high-efficiency gas-liquid separation internal component; the high-efficiency gas-liquid separation internal component includes one of a gas-liquid cyclone internal component, a cyclone separator and a herringbone tray internal component.

[0035] The disclosed method utilizes at least two scrubber stages. After a primary scrubbing and gas-solid separation of the crude syngas, the overhead syngas undergoes a secondary scrubbing, followed by a third scrubbing in a scrubber tower to further remove small amounts of solid particles carried in the syngas. The scrubber tower further captures particles in the syngas, achieving the goal of reducing and purifying the solid particle content in the syngas. This method achieves excellent syngas scrubbing and purification, resulting in a low solid particle content in the syngas after scrubbing and purification. Furthermore, the method features a simple system, a short process flow, and low energy and water consumption.

[0036] According to one embodiment of the present disclosure, the method further includes injecting a scrubbing liquid into the separation tank, the injection amount being 1wt% to 40wt% of the purified syngas, preferably 3wt% to 25wt%; the scrubbing liquid being selected from at least one of shift condensate, high-pressure ash water, demineralized water, deoxygenated water, and fresh water; the scrubbing liquid having a temperature of 100°C to 450°C, preferably 150°C to 350°C; and the separation tank being selected from at least one of a vertical separation tank and a horizontal separation tank, preferably a vertical separation tank. High-efficiency gas-liquid separation internals can be used to achieve high-efficiency gas-liquid separation.

[0037] According to one embodiment of the present disclosure, the primary scrubber S-101 and the secondary scrubber S-102 are each independently selected from one or more of a venturi scrubber, a venturi scrubber tower and a mixer.

[0038] Wash water is injected into the primary scrubber S-101 and the secondary scrubber S-102, respectively. The wash water comprises one or more of shift condensate, high-pressure ash water, desalted water, deoxygenated water, and fresh water. The temperature of the wash water can be 100°C to 450°C, preferably 150°C to 350°C, and the pressure can be 0.5MPa to 10MPa, preferably 1.0MPa to 6.5MPa. The total amount of wash liquid injected into the primary scrubber S-101 and the secondary scrubber S-102 can be 5%wt to 20%wt, preferably 8%wt to 15%wt, of the syngas. The wash water interacts with solid particles in the gas phase to scrub the gas and separate the solid particles.

[0039] According to one embodiment of the present disclosure, the primary scrubber S-101 and the secondary scrubber S-102 are respectively venturi scrubbers; the secondary scrubber can further remove a small amount of solid particles carried in the synthesis gas. The venturi scrubber includes a contraction tube, a throat tube, and an expansion tube; the flow cross-sectional area of ​​the throat tube can be 5% to 35% of the cross-sectional area of ​​the contraction tube orifice, preferably 10% to 30%, and the flow cross-sectional area of ​​the throat tube can be 3% to 30% of the cross-sectional area of ​​the expansion tube orifice, preferably 8% to 25%; Figure 4As shown, the method also includes: allowing the crude synthesis gas 101 to enter the primary scrubber from the inlet a1 of the contraction tube, allowing washing water to enter the primary scrubber from the inlet a2 of the throat pipe, obtaining the first crude synthesis gas 102 from the outlet a3 of the expansion pipe of the primary scrubber, sending the first crude synthesis gas 102 to the separation tank D-101 for separation, obtaining the tank top synthesis gas 104 and the tank bottom liquid containing solid particles 103, allowing the tank top synthesis gas 104 to enter the secondary scrubber from the inlet a1 of the contraction tube, allowing washing water to enter the secondary scrubber from the inlet a2 of the throat pipe, obtaining the second crude synthesis gas 105 from the outlet a3 of the expansion pipe of the secondary scrubber; and then sending the obtained second crude synthesis gas 105 to the scrubber tower C-101 for the third scrubbing, obtaining the purified synthesis gas 106 from the top of the scrubber tower, and obtaining the liquid material from the bottom of the scrubber tower. The operating principle of a Venturi scrubber is as follows: The high-speed syngas flow and the changes in the pipe cross-section through which it flows cause relative motion between the syngas and scrubbing water within the high-speed flow, thereby scrubbing the syngas. After the crude syngas enters the convergent tube at port a1, its velocity increases, generating a greater acceleration. The scrubbing water, introduced through port a2 due to its heavier mass, experiences less acceleration. This relative motion between the scrubbing water and the syngas creates opportunities for collision and contact, while the injected scrubbing water is atomized. Further, at the Venturi throat, the syngas velocity reaches its maximum. Due to the small pipe cross-section, the syngas and scrubbing water are compressed, reaching speeds of 50 to 150 m / s. The syngas reaches saturation, and the air film attached to the solid particles is broken, leading to intense collisions and agglomeration between the particles. As the cross-section gradually increases, the flow velocity decreases, and the pressure rises. The differential inertial forces between the gas, liquid, and solid phases generate relative motion, enabling scrubbing of the crude syngas by the scrubbing water. Furthermore, the venturi scrubber used in the present disclosure is made of a metal material or a metal composite material with good abrasion resistance and strong impact resistance. The present disclosure does not impose any specific restrictions on the material, as long as it meets the mechanical and process performance requirements of the venturi scrubber.

[0040] According to one embodiment of the present disclosure, the temperature of the crude synthesis gas 101 may be 200°C to 450°C, and the particle content may be 10 g / Nm 3 ~100g / Nm 3 The pressure can be 0.5MPa to 10MPa. Preferably, the temperature of the synthesis gas is 150℃ to 350℃, and the particle content is 20g / Nm 3 ~90g / Nm 3 , the pressure is 1.0MPa~6.5MPa.

[0041] The raw synthesis gas 101 includes one or more of coal gasifier synthesis gas, heavy oil gasifier synthesis gas, coal-oil co-gasifier synthesis gas, biomass gasifier synthesis gas and solid waste gasifier synthesis gas.

[0042] According to one embodiment of the present disclosure, the method further comprises sending the liquid containing solid particles 103 at the bottom of the tank to a downstream facility or a scrubbing tower.

[0043] According to one embodiment of the present disclosure, the method further includes: the liquid material is pressurized by the scrubbing tower bottom pump P-101, and the post-processing mode includes one or more of sending it to the downstream device to separate solid particles through liquid level control, sending it to the gasifier as quenching water, and circulating it into the scrubbing tower. Preferably, the scrubbing tower bottom material is sent back to the gasifier as quenching water, or pumped and circulated to the scrubbing tower.

[0044] According to one embodiment of the present disclosure, at least one of a tray and a filler is provided in the scrubbing tower, which can prevent solid particles from clogging the tray and causing a shortened operation cycle. The tray is a herringbone tray.

[0045] At least one washing liquid is injected into the upper and lower parts of the scrubbing tower, and the washing liquid is selected from one or more of conversion condensate, high-pressure ash water, desalted water, deoxygenated water and fresh water; the inlet temperature of the washing liquid can be 100°C to 450°C, preferably 150°C to 350°C, the pressure can be 0.5MPaG to 10MPaG, preferably 1.0MPaG to 6.5MPaG, and the injection amount can be 5wt% to 155wt% of the injection amount of the crude synthesis gas, preferably 10wt% to 125wt%. Setting a reasonable washing liquid temperature can maintain the temperature of the synthesis gas; the solid particle content in the synthesis gas 106 after washing is less than 5mg / Nm 3 .

[0046] According to one embodiment of the present disclosure, the solid particle content in the washed synthesis gas 106 can be 0.1 mg / Nm 3 ~5mg / Nm 3 , preferably 0.15 mg / Nm 3 ~4.2mg / Nm 3 .

[0047] According to one embodiment of the present disclosure, the bottoms of the separation tank and the scrubber tower independently adopt one of a circular head, an elliptical head and a conical head, preferably a conical head, and the cone angle of the conical head can be 30 to 85°, preferably 45 to 80°.

[0048] The present disclosure is further illustrated below by way of examples, but the present disclosure is not limited thereby.

[0049] Example 1

[0050] like Figure 1 and Figure 4 As shown, high-pressure grey water with a temperature of 220°C and a pressure of 7.0 MPa is injected into the first scrubber S-101 (Venturi scrubber) and the second scrubber S-102 (Venturi scrubber) as scrubbing water, and the injection amount is 9.5wt% and 7.0wt% of the injection amount of crude synthesis gas, respectively. The flow cross-sectional area of ​​the throat pipe in the Venturi scrubber is 28% of the cross-sectional area of ​​the nozzle of the contraction pipe, and the flow cross-sectional area of ​​the throat pipe is 25% of the cross-sectional area of ​​the nozzle of the expansion pipe. The temperature is 250°C and the solid particle content is 50g / Nm 3 , the coal gasifier synthesis gas 101 (270000Nm 3 / h, 260t / h, composition see Table 1) is sent to the primary scrubber S-101 for the first scrubbing, and the shift condensate with a temperature of 280°C is injected into the vertical separation tank D-101, and the injection amount is 16wt% of the injection amount of the crude synthesis gas. Then the obtained first crude synthesis gas 102 is sent to the vertical separation tank D-101 for separation to obtain the tank top synthesis gas 104 and the tank bottom liquid containing solid particles 103. The tank bottom liquid containing solid particles 103 is sent to the downstream facilities; the tank top synthesis gas 104 is sent to the secondary scrubber S-102 for a second scrubbing. Condensate is injected into the upper portion of the scrubber C-101 as the first scrubbing liquid at a temperature of 165°C, a pressure of 7.2 MPaG, and an injection rate of 55 t / h, which is 20.1% wt of the crude synthesis gas injected. High-pressure grey water is injected into the lower portion as the second scrubbing liquid at a temperature of 200°C, a pressure of 7.2 MPaG, and an injection rate of 305 t / h, which is 115% wt of the crude synthesis gas injected. The resulting second crude synthesis gas 105 is then sent to the scrubber C-101 for a third scrubbing. Purified synthesis gas 106 is obtained at the top of the scrubber. The liquid material discharged from the scrubber bottom is pressurized by the scrubber bottom pump P-101. A portion of it is returned to the scrubber as circulating scrubber bottom liquid 111, and the remaining portion is returned to the gasifier as quenching water. The solid particle content of the purified synthesis gas 106 after scrubbing is 1.2 mg / Nm 3 .

[0051] The separator tank is equipped with herringbone tray internals, while the scrubber is equipped with herringbone trays. The separator tank has an elliptical bottom end cap, while the scrubber has a conical bottom end cap, with the angle between the cone and the horizontal plane being 60°. The solids content in the syngas after scrubbing is shown in Table 2.

[0052] The amount of scrubbing water required per unit of crude synthesis gas is 1.38 tonnes of scrubbing water per tonne of crude synthesis gas. The power consumption of the purification section is 1.05 kW·h per tonne of crude synthesis gas.

[0053] The composition of the syngas from the coal gasifier is shown in Table 1.

[0054] Table 1

[0055] Gas composition unit Dry basis, numerical <![CDATA[H2]]> Vol% 58.57 CO Vol% 28.18 <![CDATA[CO2]]> Vol% 9.98 <![CDATA[N2]]> Vol% 1.51 <![CDATA[H2S]]> Vol% 0.15 COS Vol% 0.01 Ar Vol% 0.09 HCN Vol% 0.01 <![CDATA[NH3]]> Vol% 0.72 <![CDATA[CH4]]> Vol% 0.38 Solid content <![CDATA[g / Nm 3 ]]> 60

[0056] Example 2

[0057] like Figure 2 and Figure 4 As shown, the crude syngas scrubbing method of this embodiment is the same as that of Example 1, except that the solids-containing liquid 103 at the bottom of the separation tank is directly fed into the scrubbing tower, and the amount of scrubbing liquid injected into the separation tank is 15 t / h. The amount of scrubbing water required per unit of crude syngas is 1.27 t / t of scrubbing water. The power consumption of the scrubbing section is 1.01 kW·h / t of crude syngas. The solids content of the scrubbed purified syngas 106 is 1.3 mg / Nm 3 .

[0058] Example 3

[0059] like Figure 3 and Figure 4 As shown, the crude syngas scrubbing method of this embodiment is the same as that of Example 1, except that the herringbone tray internals in the separation tank are replaced with a cyclone separator, and the separation tank bottom is sealed with a conical head, with the angle between the head cone and the horizontal plane being 50°. A stream of the scrubber bottom liquid is pressurized by scrubber bottom pump P-101 and then fed into the gasifier as quench water. The remaining stream is fed to downstream equipment through level control for solid particle separation. Deoxygenated water is injected into the upper portion of the scrubber.

[0060] The gas phase composition of the crude synthesis gas in this example is the same as that in Example 1, except that the solid content is 85 g / Nm 3 The amount of washing water required per unit of crude synthesis gas is 1.39 t of washing water / t of crude synthesis gas. The power consumption of the purification part is 1.05 kW·h / t of crude synthesis gas. The solid particle content in the purified synthesis gas 106 after washing is 1.0 mg / Nm 3 .

[0061] Example 4

[0062] The crude syngas scrubbing method of this embodiment is the same as that of Example 1, except that no scrubbing liquid is provided in the separation tank. The scrubbing water required per unit of crude syngas is 1.26 tons of scrubbing water / ton of crude syngas. The power consumption of the purification section is 1.01 kW·h / ton of crude syngas. The solid particle content of the purified syngas 106 after scrubbing is 4.0 mg / Nm 3 .

[0063] Comparative Example 1

[0064] Synthesis gas is produced by coal-water slurry gasification technology, with a gasification pressure of 6.5 MPa and a solid content of 250 mg / Nm3 of crude synthesis gas at the gasifier outlet. 3The crude synthesis gas outlet adopts pipeline mixer + cyclone separator process to separate solid particles, and the solid particle content of the purified synthesis gas outlet is 35mg / Nm 3 ,See Figure 5 As shown in the figure, a static baffle-type pipeline mixer is used. The static baffles agitate the crude syngas and scrubbing water, increasing the probability that fine particles carried in the gas phase will interact with the scrubbing water. This captures the fine particles and transports them into the liquid phase, achieving primary syngas purification. A cyclone separator is installed within the separator and scrubber to further separate unresolved fine particles from the crude syngas. These particles enter the liquid phase at the bottom of the separator tank. Syngas purification is achieved through a two-stage separation process, the pipeline mixer and cyclone separator. The scrubbing water required per unit of crude syngas is 1.55 tons of scrubbing water per ton of crude syngas. The power consumption of the purification section is 1.81 kW·h / ton of crude syngas.

[0065] Comparative Example 2

[0066] The crude syngas scrubbing method in this comparative example was the same as in Example 1, except that a secondary scrubbing process was not performed, and the herringbone tray internals were not installed in the separation tank. The scrubbing water volume required per unit of crude syngas was 1.45 tonnes of scrubbing water per tonne of crude syngas. The power consumption of the scrubbing section was 1.71 kW·h / tonne of crude syngas. The solids content of the scrubbed purified syngas 106 was 40 mg / Nm². 3 .

[0067] Test Case

[0068] The solid particle content in the washed synthesis gas was determined by online analysis according to the analysis method of national standard GB9802. The test results are listed in Table 2.

[0069] Table 2

[0070]

[0071]

[0072] It can be seen from the results in Table 2 that, compared with Comparative Examples 1 to 2, the washing conditions adopted in Examples 1 to 4 are all within the scope specified in the present disclosure, so the solid particle content in the purified synthesis gas is low and a good washing effect is achieved.

[0073] Compared with Example 4, in Example 1, a washing liquid is provided in the separation tank, so that the solid particle content in the synthesis gas after washing is less and the washing effect is better.

[0074] Compared with Comparative Example 1, Example 1 adopts a pipeline mixer and a cyclone separator process to wash the synthesis gas, and the washing effect is poor.

[0075] Compared with Comparative Example 2, Example 1 did not perform the second washing in Comparative Example 2, and no herringbone tray internals were provided in the separation tank, so the washing effect was poor.

[0076] The preferred embodiments of the present disclosure are described in detail above. However, the present disclosure is not limited to the specific details of the above embodiments. Within the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the scope of protection of the present disclosure.

[0077] 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. To avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0078] In addition, the various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A method for washing crude synthesis gas, characterized in that: The method comprises the following steps: The crude synthesis gas (101) is sent to a primary scrubber (S-101) for first scrubbing, and the resulting first crude synthesis gas (102) is then sent to a separation tank (D-101) for separation to obtain a tank top synthesis gas (104) and a tank bottom liquid containing solid particles (103); The tank top synthesis gas (104) is sent to a secondary scrubber (S-102) for a second scrubbing, and then the obtained second crude synthesis gas (105) is sent to a scrubber (C-101) for a third scrubbing, and the top of the scrubber (C-101) obtains purified synthesis gas (106), and the bottom of the scrubber obtains liquid material; Wherein, the separation tank (D-101) is provided with a high-efficiency gas-liquid separation internal component; the high-efficiency gas-liquid separation internal component includes one of a gas-liquid cyclone internal component, a cyclone separator and a herringbone tray internal component.

2. The washing method according to claim 1, wherein The method also includes injecting a washing liquid into the separation tank, with the injection amount being 1wt% to 40wt% of the injection amount of the crude synthesis gas; the washing liquid is selected from at least one of shift condensate, high-pressure ash water, desalted water, deoxygenated water and fresh water; the temperature of the washing liquid is 100°C to 450°C; and the separation tank is selected from at least one of a vertical separation tank and a horizontal separation tank, preferably a vertical separation tank.

3. The washing method according to claim 1, wherein The primary scrubber (S-101) and the secondary scrubber (S-102) are each independently selected from one or more of a venturi scrubber, a venturi scrubber tower, and a mixer; Washing water is respectively injected into the primary scrubber (S-101) and the secondary scrubber (S-102), and the washing water comprises one or more of conversion condensate, high-pressure ash water, desalted water, deoxygenated water and fresh water; the temperature of the washing water is 100°C to 450°C, and the pressure is 0.5MPa to 10MPa; the total amount of washing water injected into the primary scrubber (S-101) and the secondary scrubber (S-102) is each independently 5wt% to 20wt% of the injection amount of the crude synthesis gas.

4. The washing method according to claim 3, wherein The first-stage scrubber (S-101) and the second-stage scrubber (S-102) are respectively Venturi scrubbers; the Venturi scrubbers include a contraction tube, a throat tube and an expansion tube; the flow cross-sectional area of ​​the throat tube is 5% to 35% of the cross-sectional area of ​​the contraction tube orifice, and the flow cross-sectional area of ​​the throat tube is 3% to 30% of the cross-sectional area of ​​the expansion tube orifice.

5. The washing method according to claim 1, wherein The temperature of the crude synthesis gas (101) is 200°C to 450°C, and the particle content is 10g / Nm 3 ~100g / Nm 3 , the pressure is 0.5MPa~10MPa, preferably, the temperature of the crude synthesis gas (101) is 150℃~350℃, and the particle content is 20g / Nm 3 ~90g / Nm 3 , pressure is 1.0MPa~6.5MPa; The raw synthesis gas (101) includes one or more of coal gasifier synthesis gas, heavy oil gasifier synthesis gas, coal-oil co-gasifier synthesis gas, biomass gasifier synthesis gas and solid waste gasifier synthesis gas.

6. The washing method according to claim 1, wherein The method further comprises sending the liquid (103) containing solid particles at the bottom of the tank to a downstream facility or a scrubbing tower.

7. The washing method according to claim 1, wherein The liquid material is processed in one or more ways including sending it to a downstream device for separation of solid particles, sending it to a gasification furnace as quenching water, and circulating it into a scrubbing tower.

8. The washing method according to claim 1, wherein The scrubbing tower is provided with at least one of a tower tray and a filler, wherein the tower tray is a herringbone tower tray; At least one washing liquid is injected into the scrubbing tower (C-101), wherein the washing liquid is selected from one or more of shift condensate, high-pressure ash water, desalted water, deoxygenated water, and fresh water; the inlet temperature of the washing liquid is 100° C. to 450° C., the pressure is 0.5 MPaG to 10 MPaG, and the injection amount is 5 wt% to 155 wt% of the injection amount of the crude synthesis gas; The solid particle content in the purified synthesis gas (106) is less than 5 mg / Nm 3 .

9. The washing method according to claim 8, characterized in that The solid particle content in the purified synthesis gas (106) is 0.1 mg / Nm 3 ~5mg / Nm 3 .

10. The washing method according to claim 1, wherein The bottoms of the separation tank (D-101) and the scrubber (C-101) independently adopt one of a circular head, an elliptical head and a conical head, preferably a conical head; the cone angle of the conical head is 30° to 85°.

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