CN217909691U - Energy-saving and water-saving carbon capture device - Google Patents

Abstract

The utility model provides an energy-saving and water-saving carbon trapping device, which comprises a desulfurization unit, an absorption tower and a desorption tower, wherein the desulfurization unit is provided with a flue gas inlet and a flue gas outlet, and the flue gas outlet is connected with the flue gas inlet arranged on the absorption tower; an MEA lean solution inlet is formed in the absorption tower and connected with an MEA lean solution outlet formed in the desorption tower; an MEA rich liquid outlet formed in the absorption tower is connected with an MEA rich liquid inlet formed in the desorption tower; a carbon dioxide outlet is formed in the desorption tower; the utility model discloses can improve CO ₂ The absorption rate is equivalent to the reduction of the trapping energy consumption; simultaneously, can effectively reduce the whole water consumption of system.

Description

A carbon capture device that saves energy and water

technical field

The utility model belongs to the field of environment, in particular to an energy-saving and water-saving carbon capture device.

Background technique

Climate warming has attracted close attention worldwide, and _CO2 is one of the most important greenhouse gases in the atmosphere. As a key industry of carbon dioxide emissions, the flue gas tail gas of thermal power plants in the power industry contains a large amount of carbon dioxide, which is directly discharged to the atmosphere in the current process. With the establishment of the national carbon emissions trading market, carbon emissions are directly related to the economic interests of enterprises, and the demand for _CO2 capture gradually emerges.

The MEA monoethanolamine method is a common method for capturing CO2. The regeneration cycle is realized through the absorption and desorption of MEA. However, the regeneration process requires the use of high-temperature heat sources. Generally, steam turbines in power plants are used to extract steam, resulting in high overall energy consumption of the technology. At the same time, the flue gas temperature at the outlet of the wet desulfurization tower of a coal-fired power plant is relatively high, which is higher than the requirements of the MEA process for the flue gas temperature, and the CO2 absorption rate is low.

For combined heat and power units, recovering waste heat from the system is one of the best ways to increase heating capacity without increasing the size of the unit. At present, power plants usually use water spraying to reduce the flue gas to 50-60°C before discharging, and the heat in it is not recovered, resulting in a waste of energy.

CN 109454620 A discloses a coupling device for carbon capture and waste heat recovery, which utilizes an absorption tower and a desorption tower to capture and store CO2 in high-temperature flue gas discharged from industry, and perform certain waste heat recovery. However, in this scheme, the flue gas temperature of the absorption tower is high, the CO2 absorption rate is low, and it does not have the effect of saving water.

Contents of the invention

The purpose of this utility model is to provide an energy-saving and water-saving carbon capture device, which solves the problem of high flue gas temperature at the entrance of the absorption tower and low _CO2 absorption rate in the prior art. At the same time, the prior art only considered energy saving and did not consider the system save water.

In order to achieve the above object, the technical scheme that the utility model adopts is:

An energy-saving and water-saving carbon capture device provided by the utility model includes a desulfurization unit, an absorption tower and a desorption tower, wherein a flue gas inlet and a flue gas outlet are provided on the desulfurization unit, and the flue gas outlet is connected to The flue gas inlet opened on the absorption tower;

An MEA poor liquid inlet is provided on the absorption tower, and the MEA poor liquid inlet is connected to the MEA poor liquid outlet provided on the desorption tower;

The MEA rich liquid outlet opened on the absorption tower is connected with the MEA rich liquid inlet opened on the desorption tower;

A carbon dioxide outlet is opened on the desorption tower.

Preferably, the desulfurization unit includes a desulfurization tower and a flash tank, wherein a flue gas inlet and a flue gas outlet are provided on the desulfurization tower, and the flue gas outlet is connected to the flue gas inlet provided on the absorption tower; the desulfurization The slurry outlet on the tower is connected to the slurry inlet on the flash tank; the slurry outlet on the flash tank is connected to the slurry inlet on the desulfurization tower.

Preferably, a second heat exchange unit is arranged between the slurry outlet on the desulfurization tower and the slurry inlet on the flash tank.

Preferably, the second heat exchange unit is a heat exchanger.

Preferably, the heat exchange unit includes an absorption heat pump and a lean-rich liquid heat exchanger, wherein the MEA rich liquid outlet opened on the absorption tower is connected to the desorption tower through the lean-rich liquid heat exchanger and the absorption heat pump in sequence The MEA rich liquid inlet opened on the

The MEA lean liquid outlet opened on the desorption tower passes through the lean-rich liquid heat exchanger in turn and the heat exchanger is connected to the MEA lean liquid inlet opened on the absorption tower.

Preferably, the absorption heat pump is provided with a driving steam inlet and a second condensed water outlet, and the second condensed water outlet is connected to a clean water tank.

Preferably, the steam outlet of the desulfurization unit is connected to the steam inlet of the absorption heat pump; the first condensed water outlet opened on the absorption heat pump is connected to the condensed water inlet opened on the desorption tower.

Compared with the prior art, the beneficial effects of the utility model are:

The utility model provides an energy-saving and water-saving carbon capture device, which reduces the temperature of the desulfurization slurry by flashing the desulfurization slurry, thereby reducing the temperature of the flue gas discharged from the desulfurization tower, and effectively improving the absorption rate of _CO2 in the flue gas in the absorption tower . The desulfurization slurry is flashed to extract heat from the desulfurization slurry. In fact, the heat in the flue gas is used. This part of the heat is used to heat the MEA rich liquid after being upgraded by the absorption heat pump, which can effectively reduce the impact on the power plant during the MEA regeneration process. Steam consumption, thereby reducing regeneration energy consumption. The low-temperature desulfurization slurry after flash evaporation is used as a cold source to further cool the MEA rich liquid and increase the _CO2 absorption rate, which is equivalent to reducing the energy consumption of capture.

Furthermore, the condensed water of the flash steam is sent to the desorption tower as make-up water, effectively reducing the overall water consumption of the system.

Description of drawings

Fig. 1 is the structural representation of the utility model.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is described in further detail.

An energy-saving and water-saving carbon capture device provided by the utility model includes a desulfurization unit, an absorption tower 2 and a desorption tower 3, wherein a flue gas inlet and a flue gas outlet are provided on the desulfurization unit, and the flue gas The outlet is connected to the flue gas inlet provided on the absorption tower 2;

The absorption tower 2 is provided with an MEA poor liquid inlet, and the MEA poor liquid inlet is connected to the MEA poor liquid outlet provided on the desorption tower 3;

The MEA rich liquid outlet that offers on the absorption tower 2 is connected with the MEA rich liquid inlet that offers on the desorption tower 3;

The desorption tower 3 is provided with a carbon dioxide outlet.

As shown in Figure 1, an energy-saving and water-saving carbon capture device provided by the utility model includes a desulfurization tower 1, an absorption tower 2, a desorption tower 3, a flash tank 4, an absorption heat pump 5, a heat exchanger 6, Lean-rich liquid heat exchanger 7, flue gas 8, high temperature desulfurization slurry 9, saturated wet flue gas 10, low temperature desulfurization slurry 11, flash steam 12, condensed water 13, driving steam 14, condensed water 15, MEA rich liquid 16 , high temperature rich liquid 18, MEA lean liquid 19, CO ₂ rich gas 20 and flue gas 21, wherein:

The desulfurization tower 1 is provided with a flue gas inlet and a slurry outlet, and the slurry outlet is connected to the slurry inlet provided on the flash tank 4 .

The steam outlet opened on the flash tank 4 is connected to the steam inlet opened on the absorption heat pump 5 .

The slurry outlet opened on the flash tank 4 is connected to the slurry inlet opened on the desulfurization tower 1 through the heat exchanger 6 .

The absorption heat pump 5 is provided with a driving steam inlet and a second condensed water outlet, and the second condensed water outlet is connected to a clean water tank.

The absorption heat pump 5 is provided with a first condensed water outlet, and the first condensed water outlet is connected to the condensed water inlet on the desorption tower 3 .

The flue gas outlet opened on the desulfurization tower 1 is connected to the flue gas inlet on the absorption tower 2 .

The MEA lean liquid outlet opened on the desorption tower 3 is connected to the MEA lean liquid inlet on the absorption tower 2 through the lean-rich liquid heat exchanger 7 and the heat exchanger 6 in sequence.

The MEA rich liquid outlet opened on the absorption tower 2 is connected to the MEA rich liquid inlet opened on the desorption tower 3 through the lean-rich liquid heat exchanger 7 and the absorption heat pump 5 in sequence.

The desorption tower 3 is provided with a carbon dioxide outlet.

Working process of the present utility model:

The flue gas 8 enters the desulfurization tower 1 to exchange heat with the low-temperature desulfurization slurry sprayed from the top of the tower and is purified, and the flue gas is cooled and humidified; the high-temperature desulfurization slurry 9 at the bottom of the desulfurization tower 1 enters the flash tank 4, and flash occurs in a vacuum environment. Steaming produces flash steam 12 and low-temperature desulfurization slurry 11, and heat is transferred from the desulfurization slurry to the flash steam.

The flash steam 12 enters the absorption heat pump 5, and the driving steam 14 is used for upgrading and heating the MEA rich liquid.

The driving steam is condensed in the absorption heat pump 5 and returns to the clean water tank as condensed water 15 , and the flash steam 12 is condensed as condensed water 13 and enters the desorption tower 3 .

The purified saturated wet flue gas 10 enters the absorption tower 2 and contacts the MEA lean liquid sprayed from the top of the tower in countercurrent, the CO ₂ in the flue gas is absorbed, and the flue gas 21 after the CO ₂ is absorbed is discharged from the top of the absorption tower.

The MEA rich liquid 16 is discharged from the bottom of the absorption tower 2, and after being heated by the lean-rich liquid heat exchanger 7, it enters the absorption heat pump 5 to be further heated to a high-temperature rich liquid 18, and then enters the desorption tower 3 for desorption.

After the desorbed MEA poor liquid 19 is cooled by the lean-rich liquid heat exchanger 7 , it further exchanges heat with the low-temperature desulfurization slurry in the heat exchanger 6 to cool down, and then enters the absorption tower 2 for circulation.

The desorbed CO ₂ -rich gas 20 is discharged from the top of the tower and then compressed and condensed to obtain high-purity CO ₂ .

The utility model has the following effects:

1. By flashing the desulfurization slurry, the temperature of the desulfurization slurry is reduced, thereby reducing the temperature of the flue gas discharged from the desulfurization tower, and effectively improving the absorption rate of CO2 in the flue gas in the absorption tower.

2. Through the flash evaporation of desulfurization slurry, the heat is extracted from the desulfurization slurry. In fact, the heat in the flue gas is used. This part of the heat is used to heat the MEA rich liquid after being upgraded by the absorption heat pump, which can effectively reduce the MEA regeneration process. Consumption of power plant steam, thereby reducing regeneration energy consumption.

3. The low-temperature desulfurization slurry that has been flashed is used as a cold source to further cool the MEA rich liquid and increase the _CO2 absorption rate, which is equivalent to reducing the energy consumption of capture.

4. The condensed water of the flash steam is sent to the desorption tower as make-up water, effectively reducing the overall water consumption of the system.

The utility model reduces the temperature of the desulfurization slurry by flashing the desulfurization slurry, thereby reducing the temperature of the flue gas discharged from the desulfurization tower, and effectively improving the absorption rate of _CO2 in the flue gas in the absorption tower. The desulfurization slurry is flashed to extract heat from the desulfurization slurry. In fact, the heat in the flue gas is used. This part of the heat is used to heat the MEA rich liquid after being upgraded by the absorption heat pump, which can effectively reduce the impact on the power plant during the MEA regeneration process. Steam consumption, thereby reducing regeneration energy consumption. The low-temperature desulfurization slurry after flash evaporation is used as a cold source to further cool the MEA rich liquid and increase the _CO2 absorption rate, which is equivalent to reducing the energy consumption of capture. The flash steam condensate is sent to the desorption tower as make-up water, effectively reducing the overall water consumption of the system.

Claims (8)

1. The energy-saving and water-saving carbon capture device is characterized by comprising a desulfurization unit, an absorption tower (2) and a desorption tower (3), wherein the desulfurization unit is provided with a flue gas inlet and a flue gas outlet, and the flue gas outlet is connected with the flue gas inlet formed in the absorption tower (2);

an MEA lean solution inlet is formed in the absorption tower (2) and is connected with an MEA lean solution outlet formed in the desorption tower (3);

an MEA rich liquid outlet formed in the absorption tower (2) is connected with an MEA rich liquid inlet formed in the desorption tower (3);

and a carbon dioxide outlet is formed in the desorption tower (3).

2. The energy-saving and water-saving carbon capture device according to claim 1, wherein the desulfurization unit comprises a desulfurization tower (1) and a flash tank (4), wherein a flue gas inlet and a flue gas outlet are formed in the desulfurization tower (1), and the flue gas outlet is connected with a flue gas inlet formed in the absorption tower (2); a slurry outlet formed in the desulfurizing tower (1) is connected with a slurry inlet formed in the flash tank (4); and a slurry outlet arranged on the flash tank (4) is connected with a slurry inlet on the desulfurizing tower (1).

3. The energy-saving and water-saving carbon capture device according to claim 2, wherein a second heat exchange unit is arranged between a slurry outlet formed in the desulfurizing tower (1) and a slurry inlet formed in the flash tank (4).

4. An energy and water saving carbon capture device according to claim 3, wherein the second heat exchange unit is a heat exchanger (6).

5. The energy-saving and water-saving carbon capture device according to claim 4, wherein a first heat exchange unit is arranged between the MEA rich liquid outlet formed on the absorption tower (2) and the MEA rich liquid inlet formed on the desorption tower (3).

6. The energy-saving and water-saving carbon capture device according to claim 5, wherein the first heat exchange unit comprises an absorption heat pump (5) and a lean-rich liquid heat exchanger (7), wherein an MEA rich liquid outlet formed on the absorption tower (2) is connected with an MEA rich liquid inlet formed on the desorption tower (3) through the lean-rich liquid heat exchanger (7) and the absorption heat pump (5) in sequence;

an MEA barren liquor outlet formed in the desorption tower (3) is connected with an MEA barren liquor inlet formed in the absorption tower (2) through a barren-rich liquor heat exchanger (7) and a heat exchanger (6) in sequence.

7. The energy-saving and water-saving carbon capture device according to claim 6, wherein the absorption heat pump (5) is provided with a driving steam inlet and a second condensed water outlet, and the second condensed water outlet is connected with a clean water tank.

8. The energy-saving and water-saving carbon capture device according to claim 6, wherein the steam outlet of the desulfurization unit is connected with the steam inlet of the absorption heat pump (5); a first condensed water outlet arranged on the absorption heat pump (5) is connected with a condensed water inlet arranged on the desorption tower (3).

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