MVR (Mechanical Vapor Recompression) steam energy-saving device for ionic liquid desulfurization

Abstract

The utility model relates to the technical field of environmental protection, and discloses an MVR (Mechanical Vapor Recompression) steam energy-saving device for ionic liquid desulfurization, which comprises a regeneration tower, a flash tank, a lean and rich liquid heat exchanger and a rich liquid reheater, a first output port of the flash tank is connected with a barren liquor input port of the barren liquor and rich liquor heat exchanger through a barren liquor pump, a rich liquor output port of the barren liquor and rich liquor heat exchanger is connected with a rich liquor input port of the rich liquor reheater, and a rich liquor output port of the rich liquor reheater is connected with a first input port of the regeneration tower. The system has the effects of reducing the steam consumption of the regeneration system and reducing the cost.

Description

Technical Field

[0001] The utility model relates to the technical field of environmental protection, in particular to an MVR steam energy-saving device for ion liquid desulfurization. Background Art

[0002] Ionic liquid desulfurization is an aqueous solution composed of organic cations and non-polar anions, with a small amount of activators, antioxidants, and corrosion inhibitors added. No secondary pollution will be generated during use. Ionic liquid absorbs sulfur dioxide at room temperature and can be regenerated and recycled at high temperature, thereby achieving the purpose of removing and recovering SO2.

[0003] As energy shortages intensify and energy prices rise, people pay more and more attention to energy conservation and consumption reduction. Energy conservation and consumption reduction will become a powerful measure for manufacturers to reduce product costs and improve market competitiveness. Under increasingly stringent environmental protection requirements, the state has also put forward energy conservation and consumption reduction requirements for newly built desulfurization and environmental protection facilities, such as: saving electricity, saving water, saving steam, etc. For ionic liquid desulfurization devices, due to their large steam consumption and high operating costs, they have increased the burden on many companies and also restricted the promotion and development of ionic liquid desulfurization technology. Utility Model Content

[0004] The utility model aims to provide an MVR steam energy-saving device for ionic liquid desulfurization, which has the effects of reducing steam consumption of a regeneration system and lowering costs.

[0005] The above technical purpose of the utility model is achieved through the following technical scheme: an MVR steam energy-saving device for ionic liquid desulfurization, comprising a regeneration tower, a flash tank, a lean-rich liquid heat exchanger and a rich liquid reheater, wherein the first output port of the regeneration tower is connected to the first input port of the flash tank, the first output port of the flash tank is connected to the lean liquid input port of the lean-rich liquid heat exchanger through a lean liquid pump, the rich liquid output port of the lean-rich liquid heat exchanger is connected to the rich liquid input port of the rich liquid reheater, and the rich liquid output port of the rich liquid reheater is connected to the first input port of the regeneration tower.

[0006] By adopting the above technical scheme, the lean liquid at the bottom of the ion liquid desulfurization regeneration tower is sent to the flash tank. The lean liquid after flashing in the flash tank is pressurized by the lean liquid pump and sent to the lean-rich liquid heat exchanger for heat exchange with the rich liquid from the adsorption tank. The rich liquid from the adsorption tank is heated for the first time during the heat exchange with the lean liquid. The rich liquid is further heated by the rich liquid reheater to further recover the heat of the regenerated gas containing sulfur dioxide from the regeneration tower. The rich liquid is heated for the second time to a temperature close to the bubble point and then sent to the desorption section of the regeneration tower, which effectively saves steam consumption.

[0007] The utility model is further configured as follows: the lean liquid output port of the lean-rich liquid heat exchanger is connected to the lean liquid cooler, and the rich liquid input port of the lean-rich liquid heat exchanger is connected to the adsorption tank.

[0008] By adopting the above technical solution, the lean liquid after heat exchange in the lean-rich liquid heat exchanger is sent to the lean liquid cooler for cooling, and the rich liquid from the adsorption tank is sent to the rich liquid reheater after heat exchange with the lean liquid.

[0009] The utility model is further configured as follows: a flash steam output port is provided on the flash evaporation tank, and the flash steam output port of the flash evaporation tank is connected to the second input port of the regeneration tower through an MVR steam compressor.

[0010] By adopting the above technical solution, the flash steam generated by the flash evaporation of the lean liquid in the flash tank is pressurized by the MVR steam compressor, the temperature is increased, and then it is sent to the bottom of the regeneration tower as secondary steam for regeneration.

[0011] The utility model is further configured as follows: the regeneration gas inlet of the rich liquid reheater is connected to the regeneration gas outlet at the top of the regeneration tower.

[0012] By adopting the above technical scheme, the regenerated gas at the top of the regeneration tower and the rich liquid are heat exchanged in the rich liquid reheater, so that the rich liquid further recovers the heat of the regenerated gas containing sulfur dioxide, and the rich liquid is heated to a temperature close to the bubble point and then sent to the regeneration tower, saving steam consumption.

[0013] The utility model is further configured as follows: it also includes a lean liquid reheater, the second output port of the flash tank is connected to the lean liquid input port of the lean liquid reheater through a flash pump, the lean liquid output port of the lean liquid reheater is connected to the second input port of the flash tank, and the regeneration gas input port of the lean liquid reheater is connected to the regeneration gas outlet at the top of the regeneration tower.

[0014] By adopting the above technical solution, after the lean liquid exchanges heat with the regeneration gas at the top of the regeneration tower in the lean liquid reheater, the heat in the regeneration gas can be recovered and then sent to the flash tank for flash evaporation to generate flash steam.

[0015] The utility model is further configured as follows: it also includes a regeneration gas condenser and a gas-liquid separator, the regeneration gas output port of the lean liquid reheater and the regeneration gas output port of the rich liquid reheater are both connected to the input port of the regeneration gas condenser, the output port of the regeneration gas condenser is connected to the input port of the gas-liquid separator, the gas output port of the gas-liquid separator is connected to the acid making system, and the regeneration gas condenser is provided with a circulating water inlet and a circulating water outlet.

[0016] By adopting the above technical solution, the vaporized ion liquid in the regeneration tower reacts with the sulfur dioxide in the flue gas to generate regeneration gas. The regeneration gas exchanges heat with the lean liquid and the rich liquid in the lean liquid reheater and the rich liquid reheater to recover heat, and then enters the regeneration gas condenser. In the regeneration gas condenser, the temperature is reduced to below 40°C and enters the gas-liquid separator for gas-liquid separation. The gas enters the acid production system for repeated utilization.

[0017] The utility model is further configured as follows: it also includes a reboiler, the ion liquid input port of the reboiler is connected to the second output port of the regeneration tower, the ion liquid output port of the reboiler is connected to the third input port of the regeneration tower, and the reboiler is provided with a steam input port and a steam condensate output port.

[0018] By adopting the above technical solution, the ion liquid in the regeneration tower is sent to the reboiler, and indirectly exchanges heat with the steam from outside through the reboiler. After the ion liquid in the regeneration tower is heated and evaporated, the regenerated gas comes out from the top of the regeneration tower.

[0019] The utility model is further configured as follows: it also includes a reflux liquid heat exchanger, the input port of the reflux liquid heat exchanger is connected to the liquid output port of the gas-liquid separator through a reflux pump, the reflux liquid output port of the reflux liquid heat exchanger is connected to the third input port of the regeneration tower, the condensate water output port of the reflux liquid heat exchanger is connected to the outside, and the condensate water input port of the reflux liquid heat exchanger is connected to the steam condensate water output port of the reboiler.

[0020] By adopting the above technical solution, the reflux pump sends the reflux liquid generated by the gas-liquid separator to the reflux liquid heat exchanger, and the steam condensate in the reboiler is also sent to the reflux liquid heat exchanger. The reflux liquid heat exchanger will exchange heat between the reflux liquid at about 40°C and the steam condensate at about 110°C, and raise the temperature of the reflux liquid to 100 degrees Celsius before entering the regeneration tower, thereby effectively utilizing the waste heat of the steam condensate and saving steam.

[0021] The utility model is further configured as follows: the regeneration gas outlet at the top of the regeneration tower is connected to the input port of the regeneration gas condenser through a valve.

[0022] By adopting the above technical solution, when the valve is opened, the regeneration gas at the top of the regeneration tower can directly enter the regeneration gas condenser for cooling.

[0023] The beneficial effects of the utility model are:

[0024] 1. The utility model designs a flash tank to flash the lean liquid from the regeneration tower, thereby generating flash steam, which is pressurized and heated by the MVR steam compressor and then sent to the regeneration tower, and can be used as secondary steam for regeneration, thereby reducing the consumption of external steam. The MVR (steam mechanical recompression technology) regeneration process is adopted, and the use of mechanical booster regeneration can reduce the steam consumption to about 75Kg / t rich liquid, and the steam consumption is only about 50% of that of similar devices, which can keep the steam consumption of the regeneration system and the consumption of circulating water to a minimum.

[0025] 2. In the utility model, the first heating of the rich liquid utilizes the lean liquid after flash evaporation in the flash evaporator to recover the heat of the lean liquid, and the second heating utilizes the regeneration gas generated at the top of the regeneration tower to recover the heat of the regeneration gas, thereby reducing the consumption of external steam by the regeneration tower.

[0026] 3. In the utility model, the steam from outside is indirectly heat-exchanged through the reboiler to heat and evaporate the ion liquid in the regeneration tower. The regenerated gas coming out from the top of the regeneration tower is cooled to below 40°C by the regeneration gas condenser and enters the gas-liquid separator for gas-liquid separation. The gas goes to the acid-making system, and the liquid is sent to the reflux liquid heat exchanger through the reflux pump. After heat exchange with the steam condensate, the temperature is raised to 100°C and then enters the regeneration tower. The waste heat of the steam condensate is recycled, which saves steam consumption and can significantly reduce costs.

[0027] 4. In the utility model, when the steam condensate is discharged, the temperature is reduced from 110°C to 50°C through the reflux liquid heat exchanger, which can avoid the impact of high-temperature condensate on the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. 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 creative work.

[0029] Figure 1 It is a schematic diagram of the structure of the utility model.

[0030] In the figure, 1. regeneration tower; 2. flash tank; 3. lean and rich liquid heat exchanger; 4. rich liquid reheater; 5. lean liquid pump; 6. MVR steam compressor; 7. lean liquid reheater; 8. flash pump; 9. regeneration gas condenser; 10. gas-liquid separator; 11. reboiler; 12. reflux liquid heat exchanger; 13. reflux pump. DETAILED DESCRIPTION

[0031] The technical solution of the utility model will be described clearly and completely below in conjunction with specific embodiments. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of them. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0032] Example: See Figure 1 , an MVR steam energy-saving device for ionic liquid desulfurization, includes a regeneration tower 1, a flash tank 2, a lean-rich liquid heat exchanger 3 and a rich liquid reheater 4, the first output port of the regeneration tower 1 is connected to the first input port of the flash tank 2, the first output port of the flash tank 2 is connected to the lean liquid input port of the lean-rich liquid heat exchanger 3 through a lean liquid pump 5, the rich liquid output port of the lean-rich liquid heat exchanger 3 is connected to the rich liquid input port of the rich liquid reheater 4, the rich liquid output port of the rich liquid reheater 4 is connected to the first input port of the regeneration tower 1, the lean liquid output port of the lean-rich liquid heat exchanger 3 is connected to the lean liquid cooler, and the rich liquid input port of the lean-rich liquid heat exchanger 3 is connected to the adsorption tank.

[0033] Specifically, the lean liquid at the bottom of the ionic liquid desulfurization regeneration tower 1 is sent to the flash tank 2. The lean liquid after flashing in the flash tank 2 is pressurized by the lean liquid pump 5 and sent to the lean-rich liquid heat exchanger 3 for heat exchange with the rich liquid from the adsorption tank. The rich liquid from the adsorption tank is heated for the first time during the heat exchange with the lean liquid. The rich liquid is further recovered by the rich liquid reheater 4 from the regeneration tower 1. The rich liquid is heated for the second time to a temperature close to the bubble point and then sent to the desorption section of the regeneration tower 1, which effectively saves steam consumption. The lean liquid after heat exchange in the lean-rich liquid heat exchanger 3 is sent to the lean liquid cooler for cooling. The rich liquid from the adsorption tank is sent to the rich liquid reheater 4 after heat exchange with the lean liquid.

[0034] Furthermore, a flash steam outlet is provided on the flash tank 2, and the flash steam outlet of the flash tank 2 is connected to the second input port of the regeneration tower 1 through the MVR steam compressor 6. The flash steam generated by the flash evaporation of the lean liquid in the flash tank 2 is pressurized by the MVR steam compressor 6, and the temperature is increased before being sent to the bottom of the regeneration tower 1 as secondary steam for regeneration.

[0035] Furthermore, the regeneration gas inlet of the rich liquid reheater 4 is connected to the regeneration gas outlet at the top of the regeneration tower 1, and the regeneration gas at the top of the regeneration tower 1 and the rich liquid are heat exchanged in the rich liquid reheater 4, so that the rich liquid further recovers the heat of the regeneration gas containing sulfur dioxide, and the rich liquid is heated to a temperature close to the bubble point and then sent to the regeneration tower 1, saving steam consumption.

[0036] Furthermore, it also includes a lean liquid reheater 7. The second output port of the flash tank 2 is connected to the lean liquid input port of the lean liquid reheater 7 through a flash pump 8. The lean liquid output port of the lean liquid reheater 7 is connected to the second input port of the flash tank 2. The regeneration gas input port of the lean liquid reheater 7 is connected to the regeneration gas outlet at the top of the regeneration tower 1. After the lean liquid is heat-exchanged with the regeneration gas at the top of the regeneration tower 1 in the lean liquid reheater 7, the heat in the regeneration gas can be recovered and then sent to the flash tank 2 for flash evaporation, thereby generating flash steam.

[0037] Furthermore, it also includes a regeneration gas condenser 9 and a gas-liquid separator 10. The regeneration gas output port of the lean liquid reheater 7 and the regeneration gas output port of the rich liquid reheater 4 are both connected to the input port of the regeneration gas condenser 9, the output port of the regeneration gas condenser 9 is connected to the input port of the gas-liquid separator 10, and the gas output port of the gas-liquid separator 10 is connected to the acid-making system. The regeneration gas condenser 9 is provided with a circulating water inlet and a circulating water outlet. After the vaporized ion liquid in the regeneration tower 1 reacts with sulfur dioxide in the flue gas, regeneration gas is generated. After the regeneration gas exchanges heat with the lean liquid and the rich liquid in the lean liquid reheater 7 and the rich liquid reheater 4 to recover heat, it enters the regeneration gas condenser 9, is cooled to below 40°C in the regeneration gas condenser 9, enters the gas-liquid separator 10, and is separated into gas and liquid. The gas enters the acid-making system for repeated use.

[0038] Furthermore, it also includes a reboiler 11, the ion liquid input port of the reboiler 11 is connected to the second output port of the regeneration tower 1, the ion liquid output port of the reboiler 11 is connected to the third input port of the regeneration tower 1, and the reboiler 11 is provided with a steam input port and a steam condensate output port. The ion liquid in the regeneration tower 1 is fed into the reboiler 11, and indirectly exchanges heat with the steam from outside through the reboiler 11. After the ion liquid in the regeneration tower 1 is heated and evaporated, the regenerated gas comes out from the top of the regeneration tower 1.

[0039] Furthermore, it also includes a reflux liquid heat exchanger 12, the input port of the reflux liquid heat exchanger 12 is connected to the liquid output port of the gas-liquid separator 10 through a reflux pump 13, the reflux liquid output port of the reflux liquid heat exchanger 12 is connected to the third input port of the regeneration tower 1, the condensate output port of the reflux liquid heat exchanger 12 is connected to the outside, the condensate input port of the reflux liquid heat exchanger 12 is connected to the steam condensate output port of the reboiler 11, the reflux pump 13 sends the reflux liquid generated by the gas-liquid separator 10 into the reflux liquid heat exchanger 12, the steam condensate in the reboiler 11 is also sent to the reflux liquid heat exchanger 12, the reflux liquid heat exchanger 12 will exchange heat between the reflux liquid of about 40°C and the steam condensate of about 110°C, and the temperature of the reflux liquid is increased to 100 degrees Celsius before entering the regeneration tower 1, thereby effectively utilizing the waste heat of the steam condensate and saving steam.

[0040] Furthermore, the regeneration gas outlet at the top of the regeneration tower 1 is connected to the input port of the regeneration gas condenser 9 through a valve. When the valve is opened, the regeneration gas at the top of the regeneration tower 1 can directly enter the regeneration gas condenser 9 for cooling.

[0041] Working principle of this utility model:

[0042] The lean liquid at the bottom of the ionic liquid desulfurization regeneration tower 1 is sent to the flash tank 2. The lean liquid after flashing in the flash tank 2 is pressurized by the lean liquid pump 5 and sent to the lean-rich liquid heat exchanger 3 for heat exchange with the rich liquid from the adsorption tank. The rich liquid from the adsorption tank is heated for the first time during the heat exchange with the lean liquid. The rich liquid is then further heated by the rich liquid reheater 4 to further recover the heat of the regenerated gas containing sulfur dioxide from the regeneration tower 1. The rich liquid is heated for the second time to a temperature close to the bubble point and then sent to the desorption section of the regeneration tower 1.

[0043] Flash steam generated by flash evaporation of lean liquid in the flash tank 2 is pressurized by the MVR steam compressor 6, and after the temperature is increased, it is sent to the bottom of the regeneration tower 1 as secondary steam for regeneration.

Claims

1. An MVR steam energy-saving device for ionic liquid desulfurization, comprising a regeneration tower (1), characterized in that: The regeneration tower (1) further comprises a flash tank (2), a lean-rich liquid heat exchanger (3) and a rich liquid reheater (4); the first output port of the regeneration tower (1) is connected to the first input port of the flash tank (2); the first output port of the flash tank (2) is connected to the lean liquid input port of the lean-rich liquid heat exchanger (3) via a lean liquid pump (5); the rich liquid output port of the lean-rich liquid heat exchanger (3) is connected to the rich liquid input port of the rich liquid reheater (4); and the rich liquid output port of the rich liquid reheater (4) is connected to the first input port of the regeneration tower (1).

2. The MVR steam energy-saving device for ionic liquid desulfurization according to claim 1 is characterized in that: The lean liquid output port of the lean-rich liquid heat exchanger (3) is connected to the lean liquid cooler, and the rich liquid input port of the lean-rich liquid heat exchanger (3) is connected to the adsorption tank.

3. The MVR steam energy-saving device for ionic liquid desulfurization according to claim 1 is characterized in that: The flash evaporation tank (2) is provided with a flash steam output port, and the flash steam output port of the flash evaporation tank (2) is connected to the second input port of the regeneration tower (1) through an MVR steam compressor (6).

4. The MVR steam energy-saving device for ionic liquid desulfurization according to claim 1 is characterized in that: The regeneration gas inlet of the rich liquid reheater (4) is connected to the regeneration gas outlet at the top of the regeneration tower (1).

5. The MVR steam energy-saving device for ionic liquid desulfurization according to claim 4 is characterized in that: It also comprises a lean liquid reheater (7), wherein the second output port of the flash tank (2) is connected to the lean liquid input port of the lean liquid reheater (7) via a flash pump (8), the lean liquid output port of the lean liquid reheater (7) is connected to the second input port of the flash tank (2), and the regeneration gas input port of the lean liquid reheater (7) is connected to the regeneration gas outlet at the top of the regeneration tower (1).

6. The MVR steam energy-saving device for ionic liquid desulfurization according to claim 5 is characterized in that: It also includes a regeneration gas condenser (9) and a gas-liquid separator (10), wherein the regeneration gas output port of the lean liquid reheater (7) and the regeneration gas output port of the rich liquid reheater (4) are both connected to the input port of the regeneration gas condenser (9), the output port of the regeneration gas condenser (9) is connected to the input port of the gas-liquid separator (10), the gas output port of the gas-liquid separator (10) is connected to the acid production system, and the regeneration gas condenser (9) is provided with a circulating water inlet and a circulating water outlet.

7. The MVR steam energy-saving device for ionic liquid desulfurization according to claim 6 is characterized in that: It also comprises a reboiler (11), wherein the ion liquid input port of the reboiler (11) is connected to the second output port of the regeneration tower (1), the ion liquid output port of the reboiler (11) is connected to the third input port of the regeneration tower (1), and the reboiler (11) is provided with a steam input port and a steam condensate output port.

8. The MVR steam energy-saving device for ionic liquid desulfurization according to claim 7 is characterized in that: It also includes a reflux liquid heat exchanger (12), the input port of the reflux liquid heat exchanger (12) is connected to the liquid output port of the gas-liquid separator (10) through a reflux pump (13), the reflux liquid output port of the reflux liquid heat exchanger (12) is connected to the third input port of the regeneration tower (1), the condensate output port of the reflux liquid heat exchanger (12) is connected to the outside, and the condensate input port of the reflux liquid heat exchanger (12) is connected to the steam condensate output port of the reboiler (11).

9. The MVR steam energy-saving device for ionic liquid desulfurization according to claim 6, characterized in that: The regeneration gas outlet at the top of the regeneration tower (1) is connected to the input port of the regeneration gas condenser (9) through a valve.

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