Continuous absorption unit for light oil cracking gas

Abstract

This invention provides a continuous absorption device for light oil cracking gas, belonging to the field of chemical equipment technology. It includes: a gas-liquid reaction unit, a separation unit, a tail gas purification unit, a cooling and regulating unit, a liquid-liquid mixing unit, a purification unit, and a sodium cyanide storage unit. Light oil cracking gas and sodium hydroxide solution are reacted and mixed in the gas-liquid reaction unit; the resulting sodium cyanide solution enters the separation unit to separate the absorbent from the unabsorbed gas; the separated gas enters the tail gas purification unit for further absorption; the separated liquid is cooled by a cooler; and an online conductivity monitor continuously detects the sodium cyanide and sodium hydroxide content in the absorbent. Sodium cyanide solution meeting production standards is then purified in the purification unit to obtain a high-quality sodium cyanide solution. This application enables continuous production of sodium cyanide, improving production efficiency.

Description

Technical Field

[0001] This utility model belongs to the field of chemical equipment technology, specifically relating to a continuous absorption device for light oil cracking gas. Background Technology

[0002] Sodium cyanide, as an important basic chemical raw material, is widely used in basic chemical synthesis, dyes, metallurgy and organic synthesis, pharmaceuticals, pesticides and metal processing. It also plays an important role in the mining, refining and electroplating of precious metals such as gold and silver.

[0003] Currently, the main methods for synthesizing sodium cyanide are as follows: 1. Light oil cracking method: Liquid ammonia and light oil are mixed and cracked at high temperature in a cracking furnace to generate hydrogen cyanide furnace gas. After pretreatment, the hydrogen cyanide reacts with sodium hydroxide to generate sodium cyanide solution. 2. Angle process: Natural gas, ammonia, and air are used as raw materials, and palladium-rhodium alloy is used as a catalyst to synthesize hydrogen cyanide furnace gas under high temperature conditions. After pretreatment, the hydrogen cyanide furnace gas reacts with sodium hydroxide to generate sodium cyanide solution. 3. Acrylonitrile by-product method: In the process of producing acrylonitrile through propylene ammoniation, the main by-products include gases such as hydrogen cyanide. The by-product tail gas undergoes absorption-desorption-distillation processes to obtain high-purity liquid hydrogen cyanide. The liquid hydrogen cyanide reacts with sodium hydroxide solution to generate sodium cyanide solution. 4. Methanol ammoxidation method: Liquid ammonia, methanol, and air are used as raw materials. Under the action of a catalyst with Fe-Mo oxide as the main component, hydrogen cyanide is generated. After deammoniation in a deammoniation tower, gaseous hydrogen cyanide is obtained. After absorption with sodium hydroxide solution, sodium cyanide can be obtained. In summary, all methods for producing sodium cyanide involve reacting different raw materials to obtain hydrogen cyanide gas / liquid, which is then reacted with sodium hydroxide to obtain sodium cyanide solution.

[0004] Currently, the process for producing sodium cyanide from light oil cracking gas uses intermittent absorption. Due to the unstable content of hydrogen cyanide gas produced by the light oil cracking process and the difficulty in determining the endpoint of sodium hydroxide absorption, the production system cannot operate stably, frequently resulting in excessive absorption of sodium hydroxide solution and subsequent shutdowns. Therefore, achieving continuous and stable production of sodium cyanide from light oil cracking, and solving the problems of low efficiency in intermittent production and reducing abnormal downtime, has become an urgent issue. Utility Model Content

[0005] This utility model provides a continuous absorption device for light oil cracking gas, which aims to solve the problem of low production efficiency in the intermittent production of sodium cyanide from light oil cracking in the prior art.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is: to provide a continuous absorption device for light oil cracking gas, comprising: a gas-liquid reaction unit, a separation unit, a tail gas purification unit, a cooling and regulating unit, a liquid-liquid mixing unit, a purification unit for removing impurities, and a sodium cyanide storage unit.

[0007] The gas-liquid reaction unit includes a gas-liquid reactor, and the top of the gas-liquid reactor is provided with a light oil cracking gas inlet channel and a mixed liquid inlet channel; the gas-liquid reactor is used for the continuous reaction of light oil cracking gas and sodium hydroxide solution to generate sodium cyanide solution.

[0008] The separation unit includes a first separator; a sodium cyanide solution inlet channel is provided between the liquid inlet of the first separator and the liquid outlet at the bottom of the gas-liquid reactor.

[0009] The exhaust gas purification unit includes an exhaust gas absorption tower; an unabsorbed gas inlet channel is provided between the top of the first separator and the exhaust gas absorption tower.

[0010] The cooling regulating unit includes a cooler, and the inlet of the cooler is connected to the bottom outlet of the first separator through a sodium cyanide solution outlet channel.

[0011] The liquid-liquid mixing unit includes a liquid-liquid mixer disposed on the liquid inlet channel of the mixture, and the outlet of the cooler is connected to the bottom inlet of the liquid-liquid mixer through a sodium cyanide solution cooling channel; wherein, an online conductivity monitor is disposed on the sodium cyanide solution cooling channel and is interlocked with the sodium hydroxide regulating valve on the sodium hydroxide inlet channel;

[0012] The purification unit includes an ammonia removal tower and an alkali absorption tower. The ammonia removal tower is connected to the sodium cyanide solution cooling channel via a side-source sodium cyanide solution channel. A first air inlet channel is provided between the air outlet at the top of the ammonia removal tower and the air inlet of the alkali absorption tower.

[0013] The sodium cyanide storage unit includes a sodium cyanide solution storage tank, which is connected to the deammoniation tower via a sodium cyanide solution product recovery channel.

[0014] In one possible implementation, the separation unit further includes a second separator, which is connected to the unabsorbed gas inlet channel for secondary separation of the unabsorbed gas; the liquid outlet at the bottom of the second separator is connected to the first separator through a hydrogen cyanide recovery channel.

[0015] In one possible implementation, a circulating absorption channel is provided between the bottom outlet and the top inlet of the tail gas absorption tower, and an absorption tower circulation pump is provided on the circulating absorption channel.

[0016] In one possible implementation, the purification unit further includes an acid absorption tower, which is connected to the alkali absorption tower via a second inlet channel; the acid absorption tower recycles the purified gas to the ammonia removal tower via a gas circulation channel.

[0017] In one possible implementation, an air buffer tank for drying gas is provided on the gas circulation channel, and a blower is provided on the air inlet duct between the air buffer tank and the ammonia removal tower.

[0018] In one possible implementation, a first circulation channel is provided between the bottom and top of the alkali absorption tower, and an alkali absorption circulation pump is provided on the first circulation channel.

[0019] In one possible implementation, a second circulation channel is provided between the bottom and top of the acid absorption tower, and an acid absorption circulation pump is provided on the second circulation channel.

[0020] In one feasible embodiment, a feed pump is provided on the sodium cyanide solution product recovery channel for pumping the sodium cyanide solution purified by the deammoniation tower into the sodium cyanide solution storage tank.

[0021] In one possible implementation, a bypass regulating valve is provided on the bypass sodium cyanide solution channel.

[0022] In one possible implementation, a liquid flow monitoring device is provided in the channel between the liquid-liquid mixer and the gas-liquid reactor.

[0023] The continuous absorption device for light oil cracking gas provided by this utility model has the following advantages compared with the prior art: The hydrogen cyanide furnace gas generated by the light oil cracking furnace is reacted and mixed with sodium hydroxide solution in the gas-liquid reaction unit; the reacted sodium cyanide solution enters the separation unit to separate the absorbent liquid from the unabsorbed gas; the separated gas enters the tail gas purification unit for further absorption; the separated liquid is cooled by a cooler and then enters the liquid-liquid mixing unit to mix with the sodium hydroxide solution before re-entering the gas-liquid reaction unit; simultaneously, an online conductivity monitor is installed on the sodium cyanide solution cooling channel between the cooler and the liquid-liquid mixer to detect the sodium cyanide and sodium hydroxide content in the absorbent liquid in real time; a side-collection sodium cyanide solution channel is also provided in the sodium cyanide solution cooling channel to collect qualified sodium cyanide solution; the collected sodium cyanide solution enters the impurity removal and purification unit, and after impurity removal and purification, a high-quality sodium cyanide solution is obtained, completing the process flow for producing sodium cyanide from light oil cracking.

[0024] The continuous absorption device for light oil cracking gas provided in this application has a simple processing flow, solves the problem of low production efficiency in the intermittent production of sodium cyanide, and can realize the continuous production process of sodium cyanide, thereby improving the production efficiency of sodium cyanide. Attached Figure Description

[0025] Figure 1 A schematic diagram of the structure of the continuous absorption device for light oil cracking gas provided in an embodiment of this utility model;

[0026] Figure 2 for Figure 1 A schematic diagram of the gas-liquid reaction unit is provided.

[0027] Figure 3 for Figure 1 A schematic diagram of the provided separation unit;

[0028] Figure 4 for Figure 1 A schematic diagram of the provided cooling regulation unit is shown.

[0029] Figure 5 for Figure 1 A schematic diagram of the liquid-liquid mixing unit is provided.

[0030] Figure 6 for Figure 1 A schematic diagram of the provided impurity removal and purification unit;

[0031] Explanation of reference numerals in the attached figures:

[0032] 1. Gas-liquid reaction unit; 11. Light oil cracking gas inlet channel; 12. Mixed liquid inlet channel; 13. Gas-liquid reactor; 14. Light oil cracking gas pressure monitor; 15. Mixed liquid flow monitor; 2. Separation unit; 21. First separator; 22. Sodium cyanide solution inlet channel; 23. Unabsorbed gas inlet channel; 24. Second separator; 3. Cooling and regulating unit; 31. Absorbent circulating pump; 32. Cooler; 33. Temperature monitor; 34. Online conductivity monitor; 35. Coolant regulating valve; 4. Liquid-liquid mixing unit; 41. Sodium cyanide solution cooling channel; 42. Sodium hydroxide inlet channel ; 43. Sodium cyanide solution flow monitor; 44. Sodium hydroxide regulating valve; 45. Liquid-liquid mixer; 5. Purification unit; 51. Bypass regulating valve; 52. Air buffer tank; 53. Blower; 54. Ammonia removal tower; 55. Feed pump; 56. Alkali absorption tower; 57. Alkali absorption circulation pump; 58. Acid absorption tower; 59. Acid absorption circulation pump; 6. Sodium cyanide storage unit; 61. Sodium cyanide solution storage tank; 62. Sodium cyanide extraction pump; 7. Sodium hydroxide storage unit; 71. Sodium hydroxide storage tank; 72. Sodium hydroxide feed pump; 8. Tail gas purification unit; 81. Tail gas absorption tower; 82. Absorption tower circulation pump. Detailed Implementation

[0033] To make the technical problems, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0034] Please see Figures 1 to 6 The continuous absorption device for light oil cracking gas provided by this utility model will now be described. The continuous absorption device for light oil cracking gas includes: a gas-liquid reaction unit 1, a separation unit 2, a tail gas purification unit 8, a cooling and regulating unit 3, a liquid-liquid mixing unit 4, a purification unit 5, and a sodium cyanide storage unit 6.

[0035] See Figure 2 As shown, the gas-liquid reaction unit 1 includes a gas-liquid reactor 13, and the top of the gas-liquid reactor 13 is provided with a light oil cracking gas inlet channel 11 and a mixed liquid inlet channel 12; the gas-liquid reactor 13 is used for the continuous reaction of light oil cracking gas and sodium hydroxide solution to generate sodium cyanide solution.

[0036] A liquid flow monitor 15 is installed on the liquid inlet channel 12 to monitor the feed flow rate of the liquid mixture from the liquid mixing unit 4 in real time; a light oil cracking gas pressure monitor 14 is installed on the light oil cracking gas inlet channel 11 to monitor the pressure of the light oil cracking gas in real time.

[0037] See Figure 3 As shown, the separation unit 2 includes a first separator 21; a sodium cyanide solution inlet channel 22 is provided between the liquid inlet of the first separator 21 and the bottom liquid outlet of the gas-liquid reactor 13; the separation unit 2 is used to separate the absorbable HCN gas and the unabsorbed gas components in the light oil cracking gas.

[0038] See Figure 3 As shown, the exhaust gas purification unit 8 includes an exhaust gas absorption tower 81; an unabsorbed gas inlet channel 23 is provided between the gas outlet at the top of the first separator 21 and the exhaust gas absorption tower 81; the separated gas enters the exhaust gas purification unit 8 for further absorption of the exhaust gas.

[0039] See Figure 4 As shown, the cooling regulating unit 3 includes a cooler 32. The inlet of the cooler 32 is connected to the bottom outlet of the first separator 21 through the sodium cyanide solution outlet channel. An absorbent circulation pump 31 is installed on the sodium cyanide solution outlet channel. The absorbent circulation pump 31 pumps the sodium cyanide solution in the separation unit 2 into the cooler 32 for cooling and temperature reduction, thereby regulating the temperature of the sodium cyanide solution.

[0040] A coolant regulating valve 35 is installed on the coolant inlet pipe of the cooler 32 to monitor the temperature of the absorbent in real time according to the temperature monitoring instrument 33 installed on the sodium cyanide solution cooling channel 41. The temperature monitoring instrument 33 is electrically connected to the coolant regulating valve 35 and adjusts the coolant regulating valve 35 by monitoring the absorbent temperature at the outlet of the cooler 32 in real time to ensure that the absorbent temperature in the system remains stable.

[0041] See Figure 5 As shown, the liquid-liquid mixing unit 4 includes a liquid-liquid mixer 45 disposed on the liquid inlet channel 12. The outlet of the cooler 32 is connected to the bottom inlet of the liquid-liquid mixer 45 through a sodium cyanide solution cooling channel 41. An online conductivity monitor 34 is disposed on the sodium cyanide solution cooling channel 41 and interlocked with a sodium hydroxide regulating valve 44 on the sodium hydroxide inlet channel 42. The sodium hydroxide regulating valve 44 is electrically connected to the online conductivity monitor 34. A sodium cyanide solution flow monitor 43 is also disposed on the sodium hydroxide inlet channel 42.

[0042] An online conductivity monitor 34 installed on the sodium cyanide solution cooling channel 41 monitors the conductivity of the absorbent in real time, and can adjust the feed rate of sodium hydroxide solution in the liquid-liquid mixer 45 in a timely manner to ensure that the content of sodium cyanide and sodium hydroxide is within the qualified range, and avoid the problem of unstable product quality caused by excessive or insufficient absorption of sodium hydroxide.

[0043] See Figure 6 As shown, the purification unit 5 includes an ammonia removal tower 54 and an alkali absorption tower 56. The ammonia removal tower 54 is connected to the sodium cyanide solution cooling channel 41 through a bypass sodium cyanide solution channel. A first air inlet channel is provided between the air outlet at the top of the ammonia removal tower 54 and the air inlet of the alkali absorption tower 56. The bypass sodium cyanide solution channel is used to adjust the sodium cyanide solution outflow rate and maintain the stability of the absorption liquid volume in the system.

[0044] The sodium cyanide storage unit 6 includes a sodium cyanide solution storage tank 61, which is connected to the deammoniation tower 54 via a sodium cyanide solution product recovery channel. The sodium cyanide solution purified by the impurity removal and purification unit 5 enters the sodium cyanide solution storage tank 61 for storage and later use. A sodium cyanide extraction pump 62 is installed at the outlet of the sodium cyanide solution storage tank 61 to supply sodium cyanide for production use.

[0045] The continuous absorption device for light oil cracking gas provided by this utility model has the following advantages compared with the prior art: the hydrogen cyanide furnace gas generated by the light oil cracking furnace is reacted and mixed with sodium hydroxide solution in the gas-liquid reaction unit 1; the reacted sodium cyanide solution enters the separation unit 2 to separate the absorbent liquid from the unabsorbed gas; the separated gas enters the tail gas purification unit 8 for further absorption; the separated liquid is cooled by the cooler 32 and then enters the liquid-liquid mixing unit 4 to mix with the sodium hydroxide solution before entering the gas-liquid reaction unit 1 again; at the same time, an online conductivity monitor 34 is installed on the sodium cyanide solution cooling channel 41 between the cooler 32 and the liquid-liquid mixer 45 to detect the content of sodium cyanide and sodium hydroxide in the absorbent liquid in real time; a side-collection sodium cyanide solution channel is also provided in the sodium cyanide solution cooling channel 41 to collect qualified sodium cyanide solution; the collected sodium cyanide solution enters the impurity removal and purification unit 5, and after impurity removal and purification, a high-quality sodium cyanide solution is obtained, thus completing the process flow of light oil cracking to produce sodium cyanide.

[0046] Optionally, the gas-liquid reactor 13 is made of 316L stainless steel with a diameter of Φ800-1500mm and a height of 1500-3000mm. The gas-liquid reactor 13 has multiple layers of plates arranged from top to bottom, each plate with a thickness of 2-5mm. The plates in adjacent layers are arranged in opposite directions, and the included angle between two adjacent plates is 90°. This design allows the sodium hydroxide solution to come into full contact with the light oil cracking gas and allows the HCN gas to be completely absorbed.

[0047] In some embodiments, see Figure 3 As shown, the separation unit 2 also includes a second separator 24, which is connected to the unabsorbed gas inlet channel 23 for secondary separation of the unabsorbed gas; the liquid outlet at the bottom of the second separator 24 is connected to the first separator 21 through a hydrogen cyanide recovery channel. This application improves the separation effect through a two-stage separator, thereby increasing the production efficiency of sodium cyanide.

[0048] Preferably, the first separator 21 has a size of φ1500×3000mm and is made of 316L stainless steel, and the second separator 24 has a size of φ800×2000mm and is made of 316L stainless steel. A partition is provided in the middle of the second separator 24. The partition is made of 316L stainless steel with a length of 1000mm. A demister is provided on the right side of the partition to remove foam in the solution.

[0049] In some embodiments, see Figure 3As shown, a circulating absorption channel is provided between the bottom outlet and the top inlet of the tail gas absorption tower 81, and an absorption tower circulation pump is installed on the circulating absorption channel. Inside the tail gas absorption tower 81, from top to bottom, there are sprayers, demisters, and a packing layer to purify and absorb the gas entering the tail gas absorption tower 81. The absorbed sodium hydroxide solution is recovered to the bottom of the tower, and the waste gas is discharged from the tail gas discharge channel at the top of the tail gas absorption tower 81. The absorbent in the tail gas absorption tower 81 is a sodium hydroxide solution with a concentration of 20%, which can be reused.

[0050] Optionally, the absorbent circulation pump 31 is a stainless steel centrifugal pump with a flow rate of 100 m³ / h and a head of 50 m. The cooler 32 uses circulating water as the cooling medium, with a circulating water temperature of 20-40℃. The cooler 32 is a plate heat exchanger with a heat exchange area of ​​50 m², and the liquid outlet temperature of the cooler 32 is controlled at 50-55℃. The online conductivity monitor 34 has a measurement range of 0-9000 μS / cm, uses 316L stainless steel as the electrode material, employs a 3 / 4 NPT electrode connection, and operates at a temperature of 0-100℃.

[0051] Preferably, the liquid-liquid mixer 45 is made of 316L stainless steel with dimensions of φ1000×2500mm, and the internal material is 316L stainless steel packing. The packing plates are 2mm thick, and the upper and lower adjacent packing plates are arranged in opposite directions with an included angle of 90°, which can enable the sodium hydroxide solution to fully contact and mix with the absorbent in the system.

[0052] In some embodiments, see Figure 6 As shown, the purification unit 5 also includes an acid absorption tower 58, which is connected to an alkali absorption tower 56 via a second inlet channel. The purified gas from the acid absorption tower 58 is recycled to the ammonia removal tower 54 via a gas circulation channel. The alkali absorption tower 56 contains a 20% sodium hydroxide solution to absorb hydrogen cyanide gas escaping from the ammonia removal tower 54, and the acid absorption tower 58 contains a 30% dilute sulfuric acid solution to absorb ammonia gas escaping from the ammonia removal tower 54.

[0053] In some embodiments, see Figure 6 As shown, an air buffer tank 52 for drying gas is installed in the gas circulation channel, and a blower 53 is installed on the air inlet pipe between the air buffer tank 52 and the ammonia removal tower 54. By setting up the air buffer tank 52, small droplets entrained in the tail gas of the acid absorption tower 58 are intercepted, keeping the air intake of the blower 53 dry and preventing damage to the blower 53.

[0054] The ammonia stripping tower 54 employs a stripping method, using a blower 53 to introduce air into the sodium cyanide solution. Taking advantage of the different solubility of ammonia in the alkaline solution, the ammonia escapes with the stripping gas, thus achieving the purpose of ammonia removal. The ammonia stripping tower 54 is equipped with demisters, sprayers, and packing layers arranged sequentially from top to bottom to purify the incoming sodium cyanide solution and improve the quality of the sodium cyanide solution product.

[0055] In some embodiments, see Figure 6 As shown, a first circulation channel is provided between the bottom and top of the alkali absorption tower 56, and an alkali absorption circulation pump 57 is provided on the first circulation channel to improve the absorption effect through circulation.

[0056] In some embodiments, see Figure 6 As shown, a second circulation channel is provided between the bottom and top of the acid absorption tower 58, and an acid absorption circulation pump 59 is provided on the second circulation channel to improve the absorption effect through circulation.

[0057] In some embodiments, see Figure 6 As shown, a feed pump 55 is installed on the sodium cyanide solution product recovery channel to pump the sodium cyanide solution purified by the deammoniation tower 54 into the sodium cyanide solution storage tank 61.

[0058] In some embodiments, see Figure 6 As shown, a bypass regulating valve 51 is installed on the bypass sodium cyanide solution channel. The bypass regulating valve 51 is used to adjust the outflow rate of sodium cyanide solution and maintain the stability of the absorbent volume in the absorption system.

[0059] In some embodiments, see Figure 2 As shown, a mixed liquid flow monitor 15 is installed on the channel between the liquid-liquid mixer 45 and the gas-liquid reactor 13 to monitor the flow rate of sodium hydroxide and sodium cyanide after mixing.

[0060] This application also includes a sodium hydroxide storage unit 7, which includes a sodium hydroxide storage tank 71. A sodium hydroxide feed pump 72 is provided on the mixed liquid inlet channel 12. The sodium hydroxide feed pump 72 pumps sodium hydroxide into the liquid-liquid mixer 45, mixes it with the sodium cyanide solution that enters, and then enters the gas-liquid reactor 13.

[0061] The following is an example of the use of the continuous absorption device for light oil cracking gas proposed in this application:

[0062] In use, the sodium hydroxide solution enters the gas-liquid mixing unit at a feed rate of 5000-6000 kg / h. In the gas-liquid reaction unit 1, the sodium hydroxide solution can fully contact the light oil cracking gas and the HCN gas can be completely absorbed and reacted.

[0063] After absorption, the sodium cyanide solution enters the separation unit 2, which can completely separate the unabsorbed tail gas. The absorbent enters the cooler 32 through the absorbent circulation pump 31. After being cooled by circulating water at 20-40℃, it enters the liquid-liquid mixer 45, so that the sodium hydroxide solution and the absorbent can fully contact and mix. A temperature monitoring instrument 33 is installed at the outlet of the cooler 32 and is interlocked with the coolant regulating valve 35 installed on the coolant feed pipe of the cooler 32 to ensure that the temperature of the absorbent at the outlet of the cooler 32 is 50-55℃. An online conductivity monitoring instrument 34 is installed on the connecting pipe between the cooler 32 and the liquid-liquid mixer 45 to monitor the conductivity value of the absorbent in real time. The monitored conductivity value is interlocked with the sodium hydroxide regulating valve 44 installed on the sodium hydroxide inlet channel 42.

[0064] A bypass valve 51 is installed on the connecting pipeline between the cooling regulating unit 3 and the liquid-liquid mixing unit 4 to extract the qualified sodium cyanide solution, ensuring the stability of the liquid level in the absorption system. The extracted sodium cyanide solution enters the deammoniation tower 54, where ammonia is removed by stripping. The tail gas after stripping passes through the sodium hydroxide in the alkali absorption tower 56 to absorb hydrogen cyanide, and then through the acid absorption tower 58 to absorb ammonia. The tail gas then enters the air buffer tank 52, and after passing through the blower 53, it enters the deammoniation tower 54, forming a closed loop. The qualified sodium cyanide solution after deammoniation is pumped into the sodium cyanide storage tank by the sodium cyanide extraction pump 62. It should be noted that the structure and working principle of the online conductivity monitor, flow meter, temperature meter, and pressure monitor involved in this application are all prior art, which can be fully implemented by those skilled in the art, and need not be elaborated. The content protected by this application does not involve the improvement of the software and method.

[0065] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0066] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A continuous absorption device for light oil cracking gas, characterized in that, include: Gas-liquid reaction unit (1), separation unit (2), tail gas purification unit (8), cooling regulation unit (3), liquid-liquid mixing unit (4), impurity removal and purification unit (5) and sodium cyanide storage unit (6); The gas-liquid reaction unit (1) includes a gas-liquid reactor (13), and the top of the gas-liquid reactor (13) is provided with a light oil cracking gas inlet channel (11) and a mixed liquid inlet channel (12); the gas-liquid reactor (13) is used for the continuous reaction of light oil cracking gas and sodium hydroxide solution to generate sodium cyanide solution. The separation unit (2) includes a first separator (21); a sodium cyanide solution inlet channel (22) is provided between the liquid inlet of the first separator (21) and the bottom liquid outlet of the gas-liquid reactor (13); The exhaust gas purification unit (8) includes an exhaust gas absorption tower (81), and an unabsorbed gas inlet channel (23) is provided between the top of the first separator (21) and the exhaust gas absorption tower (81). The cooling regulating unit (3) includes a cooler (32), and the inlet of the cooler (32) is connected to the bottom outlet of the first separator (21) through a sodium cyanide solution outlet channel. The liquid-liquid mixing unit (4) includes a liquid-liquid mixer (45) disposed on the liquid inlet channel (12) of the mixture. The outlet of the cooler (32) is connected to the bottom inlet of the liquid-liquid mixer (45) through a sodium cyanide solution cooling channel (41). An online conductivity monitor (34) is disposed on the sodium cyanide solution cooling channel (41) and is interlocked with the sodium hydroxide regulating valve (44) on the sodium hydroxide inlet channel (42) disposed on the liquid inlet of the liquid-liquid mixer (45). The purification unit (5) includes an ammonia removal tower (54) and an alkali absorption tower (56). The ammonia removal tower (54) is connected to the sodium cyanide solution cooling channel (41) through a bypass sodium cyanide solution channel. A first air inlet channel is provided between the air outlet at the top of the ammonia removal tower (54) and the air inlet of the alkali absorption tower (56). The sodium cyanide storage unit (6) includes a sodium cyanide solution storage tank (61), which is connected to the deammoniation tower (54) through a sodium cyanide solution product recovery channel.

2. The continuous absorption device for light oil cracking gas as described in claim 1, characterized in that, The separation unit (2) further includes a second separator (24), which is connected to the unabsorbed gas inlet channel (23) for secondary separation of the unabsorbed gas; the liquid outlet at the bottom of the second separator (24) is connected to the first separator (21) through the hydrogen cyanide recovery channel.

3. The continuous absorption device for light oil cracking gas as described in claim 1, characterized in that, A circulating absorption channel is provided between the bottom liquid outlet and the top liquid inlet of the tail gas absorption tower (81), and an absorption tower circulating pump (82) is provided on the circulating absorption channel.

4. The continuous absorption device for light oil cracking gas as described in claim 1, characterized in that, The purification unit (5) further includes an acid absorption tower (58), which is connected to the alkali absorption tower (56) through a second air inlet channel; the acid absorption tower (58) recycles the purified gas to the deammoniation tower (54) through a gas circulation channel.

5. The continuous absorption device for light oil cracking gas as described in claim 4, characterized in that, An air buffer tank (52) for drying gas is provided on the gas circulation channel, and a blower (53) is provided on the air inlet pipe between the air buffer tank (52) and the ammonia removal tower (54).

6. The continuous absorption device for light oil cracking gas as described in claim 4, characterized in that, A first circulation channel is provided between the bottom and top of the alkali absorption tower (56), and an alkali absorption circulation pump (57) is provided on the first circulation channel.

7. The continuous absorption device for light oil cracking gas as described in claim 4, characterized in that, A second circulation channel is provided between the bottom and top of the acid absorption tower (58), and an acid absorption circulation pump (59) is provided on the second circulation channel.

8. The continuous absorption device for light oil cracking gas as described in claim 1, characterized in that, A feed pump (55) is installed on the sodium cyanide solution product recovery channel to pump the sodium cyanide solution purified by the deammoniation tower (54) into the sodium cyanide solution storage tank (61).

9. The continuous absorption device for light oil cracking gas as described in claim 1, characterized in that, A bypass regulating valve (51) is installed on the bypass sodium cyanide solution channel.

10. The continuous absorption device for light oil cracking gas as described in claim 1, characterized in that, A liquid flow monitoring instrument (15) is installed in the channel between the liquid-liquid mixer (45) and the gas-liquid reactor (13).

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