WO2015000701A1

WO2015000701A1 - Installation for depositing co2 and method for operating such an installation

Info

Publication number: WO2015000701A1
Application number: PCT/EP2014/062843
Authority: WO
Inventors: Norbert Pieper; Henning Schramm; Michael Wechsung
Original assignee: Siemens Aktiengesellschaft
Priority date: 2013-07-02
Filing date: 2014-06-18
Publication date: 2015-01-08

Abstract

The invention relates to an installation for depositing CO₂ from an exhaust gas stream of a charge-dependent combustion device, comprising a CO₂ depositing device (1), wherein the CO₂ depositing device (1) is fluidically coupled with the combustion device, wherein the CO₂ depositing device (1) has a desorber (5) and an absorber (3), wherein a compressor unit (30) is fluidically connected downstream of the desorber (5) and is intended for compressing a CO₂-carrying gas mass flow discharged from the CO₂ depositing device (1), and wherein the desorber (5) has a desorber pressure, which can be set load-dependently by way of the compressor unit (30). The invention also relates to a method for operating such an installation.

Description

description

Apparatus for separating C0 ₂ and method for operating such a plant

The invention relates to a plant for the separation of C0 ₂ from an exhaust stream of a load-dependent combustion device, comprising a C0 ₂ -Abscheidevorrichtung, wherein the C0 ₂ -Abscheidevorrichtung is fluidly coupled to the combustion device, wherein the C0 ₂ -Abscheidevorrichtung a desorber and an absorber wherein the desorber fluidly downstream of a compressor unit, which is intended to densify a derived from the C0 ₂ -Abscheidevorrichtung, C0 ₂ -conducting gas mass flow. Furthermore, the invention relates to a method for operating such a system.

In fossil-fired power plants, the combustion of a fossil fuel produces a carbon dioxide-containing exhaust gas. This exhaust gas is usually released into the atmosphere. The carbon dioxide accumulating in the atmosphere impedes the heat radiation of our earth and leads thereby by the so-called greenhouse effect to an increase of the earth's surface temperature. In order to achieve a reduction of the carbon dioxide emission in fossil-fired power plants, carbon dioxide can be separated from the exhaust gas.

For the separation of carbon dioxide from a gas mixture, various methods are generally known. A known method is the separation of carbon dioxide from an exhaust gas after a combustion process (post-combustion C0 ₂ capture - Postcap). In this process, the carbon dioxide is separated off with a detergent in an absorption-desorption process.

In a classical absorption-desorption process, the exhaust gas is in an absorption column with a selective The solvent is brought into contact as a detergent. The absorption of carbon dioxide takes place by a chemical or physical process. The purified exhaust gas is discharged from the absorption column for further processing or discharge. The loaded with carbon dioxide solvent is passed to separate the carbon dioxide and regeneration of the solvent in a desorption column. The separation in the desorption column can be carried out thermally. In this case, a gas-vapor mixture of gaseous carbon dioxide and vaporized solvent is expelled from the loaded solvent. The evaporated solvent is then separated from the gaseous carbon dioxide. The carbon dioxide can now be compressed and cooled in several stages. In liquid, supercritical or frozen state, the carbon dioxide can then be sent for storage or recycling. The regenerated solvent is passed again to the absorber column, where it can again absorb carbon dioxide from the exhaust gas containing carbon dioxide. For expelling the carbon dioxide from the loaded solvent, a heat output at a temperature level of about 120 to 150 ° C is required. This heat output can be provided by steam, which is taken from the steam turbine plant. After passing through the desorption column, the vapor condenses and is returned to the steam cycle.

A steam turbine plant usually consists of one

High, medium and low pressure parts. A steam introduced into the high-pressure part is gradually expanded via the middle and the subsequent low-pressure part. Between the high and the medium-pressure part regularly takes place reheating. The delimitation of medium and low pressure part is usually characterized by a Dampfentnahmemöglichkeit on the overflow between medium and low pressure part. The removal of steam from the overflow line for the purpose of C0 ₂ separation is comparable to a process steam extraction, as is customary for example for district heating. The amount of extracted steam is dependent on the operation of the process steam consumer or the separator and can vary quite from 0% to 65%. The amount of steam removed leads to a reduction of the steam mass flow, which is supplied to the subsequent turbine stage.

As a result of Dampfentnähme now the vapor pressure at the discharge point will decrease to the same extent. The vapor pressure also reduces the condensation temperature during heat dissipation. Since every heat consumer needs a defined temperature level, the vapor pressure at the extraction point must not fall below the associated saturated steam pressure.

To address this problem, it is known from the prior art to switch a throttle device in front of the low-pressure turbine. This makes it possible to adjust the pressure according to the temperature requirement of a corresponding heat consumer. The disadvantage, however, is that the throttling of the remaining steam thermodynamically leads to a high loss.

A general disadvantage of steam power plants with process steam consumers, which are known from the prior art, either the lossy throttling required for operation with steam extraction or the loss of excess steam, which is obtained in the operating state without steam extraction, and are passed unused into the condenser got to. These losses lead to an undesirable deterioration of the overall efficiency of the steam power plant. The cost-effectiveness of such a steam power plant with process steam extraction is therefore significantly lower. A first object of the invention is therefore to specify a plant for deposition of C0 ₂ , which avoids the above-mentioned problem. A second task is the specification of a method for the operation of such a system.

The first object is achieved by specifying a system for the separation of C0 ₂ from a flue gas stream of a load-dependent combustion apparatus comprising a C0 device ₂ -Abscheide-, wherein the C0 ₂ -Abscheidevorrichtung fluid power cally with the combustion device coupled to said C0 ₂ -Abscheidevorrichtung having a desorber and an absorber, wherein the desorber fluidly a

Downstream of the compressor unit, which is intended to compress a derived from the C0 ₂ -Abscheidevorrichtung, C0 ₂ -conducting gas mass flow, and wherein the desorber has a desorber pressure which over the

Compressor unit is load-dependent adjustable.

In previously known concepts, throttling losses due to a throttle valve according to the prior art are accepted for the CO ₂ separation from an exhaust gas flow by the heat of process steam from the overflow line. By means of the invention, the pressure in the desorber is now adapted to changed load conditions in the power plant. By varying the Desorberdrucks the required temperature level of the C0 ₂ can thus move -Abscheideprozesses, ie with increasing Desorberdruck the power demand, which is required for Desoption of C0 ₂ and increases with decreasing

Desorber pressure reduces the energy required for desorption of C0 ₂ . With the help of the invention, this degree of freedom is now used especially at partial loads. By the compressor unit, the desorber pressure is now adjusted load-dependent to the required level. It is the

Compressor unit now designed at least with a compressor. The compressor unit may also include a compressor with appropriately upstream control element, eg a valve. The Dersorberdruck can therefore either directly via the compressor or via the control organ adjustable be. Also, a setting on the compressor, which is supported by the control element, is conceivable.

The expelled from the detergent C0 ₂ mass flow is dissipated in each load condition of the compressor unit. This can now promote the corresponding volume flow in a large storage volume constant pressure for further use. With the invention advantageously also the load range of the compressor can be extended also, as always a substantially constant C0 ₂ -Volumenstrom must be processed. Thus, for example, the half C0 ₂ volumetric flow at half the desorber pressure at partial load results in the same C0 ₂ volume flow as at full load the full C0 ₂ mass flow. In this case, the desorber pressure can be adjusted load-dependent, above all, via the admission pressure of the compressor unit.

The desorber is preferably thermally coupled to a process steam-conducting device, wherein the process steam has a process steam pressure, and wherein the desorber pressure is adapted to the process steam pressure. In a preferred embodiment, the process vapor pressure is designed as a sliding pressure. Furthermore, the system preferably has at least two turbines. These are connected to each other via an overflow line. The process steam can be taken from the overflow line.

This means that the desorber pressure in the desorber is adjusted depending on the load state such that the required process steam pressure corresponds to the natural sliding pressure, for example, between the medium-pressure and low-pressure turbine. As a result, can be largely dispensed with a throttle valve according to the prior art. However, even with the use of a throttle account in each case, the throttle losses at partial load, which would amount to more than 10 MW, for example, in an 800 MW combustion system at half load. The thermo-technical coupling of the desorber to a process vapor-carrying device via a

Reboilerwärmetauscher done. Preferably, the incinerator is a power plant, in particular a gas and steam power plant, which is operable with respect to a load, the desorber pressure decreasing as the load is reduced.

In a preferred embodiment of the invention, the desorber pressure on the operation of the compressor unit, in particular the compressor, adjustable. The mode of operation preferably comprises at least the drive power and / or the operating point. Depending on the drive power and operating point of the compressor unit adjusts load-dependent a certain form, which is also present in the desorber.

The operating point can now be changed either by changing the speed or by using a Vorleitgitters. The pre-pressure and thus the adjusting desorber pressure of a constant-speed C0 ₂ -evaporator unit are kept constant by adjusting the position of a Vorleitgitters. In the partial load, the C0 ₂ mass flow is now limited.

In a preferred embodiment, the process vapor pressure can be measured by arranging process steam measuring devices.

Preferably, the desorber pressure can be measured by arranged desorber measuring devices. In this case, the desorber measuring devices and the process steam measuring devices

Return measured values. The compressor unit is now preferably adjustable on the basis of the measured values.

The task related to the method is characterized by specifying a method for operating a plant as described above for the deposition of C0 ₂ , comprising a C0 ₂ -Abscheide- device with a desorber and an absorber, wherein the desorber fluidly downstream of a compressor unit is, wherein the desorber has a desorber pressure, which is adjusted load-dependent via the compressor unit.

The desorber is preferably thermally coupled to a process steam-conducting device, wherein the process steam has a process steam pressure, and wherein the desorber pressure is adapted to the process steam pressure.

Thereby, the temperature level of the desorption and thus the required process steam pressure in each load condition can be adjusted to the prevailing pressure in the conduit used for branching off the process steam, i. be adapted here in the overflow between medium pressure and low pressure turbine. If the load in the power plant drops, so does the process steam pressure and according to the invention

Desorber pressure in the desorber. The process steam pressure is therefore not constant, but adapted to the natural sliding pressure. Further features, properties and advantages of the present invention will become apparent from the following description with reference to the accompanying figures. 1 shows a C0 ₂ -Abscheidevorrichtung according to the prior

Technology;

2 shows a steam power plant according to the prior art;

3 shows a schematic diagram of the invention. 1 shows schematically and not conclusively a C0 ₂ -

Separator 1 for carbon dioxide from an exhaust gas stream. Other components can of course be present. The CO ₂ separation device 1 comprises an absorber 3 and a desorber 5 connected fluidically thereto.

For separating carbon dioxide from the flue gas of an incinerator, the flue gas is introduced into the C0 ₂ - Abscheidevor- direction 1 forwarded. For this purpose, the flue gas is supplied to the absorber 3 via a flue gas line 7.

In the absorber 3, there is an aqueous amino acid salt solution as the washing medium 9, which is used for separating off the imine

Flue gas contained carbon dioxide is used. For this purpose, the flue gas in the absorber 3 is brought into contact with the washing medium 9 and the carbon dioxide contained in the flue gas in

Wash medium 9 absorbed. The gas mass flow purified by carbon dioxide is released from the absorber 3 at the absorber head 11.

Via a discharge line 13, the absorber 3 is fluidically connected to a feed line 15 of the desorber 5, so that the loaded with carbon dioxide washing medium 9 can be pumped via these two lines 13, 15 with temperature increase by means of a pump 17 in the desorber 5.

In this case, the loaded washing medium 9 passes through a heat exchanger 19, in which the heat of the regenerated washing medium 9 flowing from the desorber 5 to the absorber 3 is transferred to the laden washing medium 9 supplied to the desorber 5 by the absorber 3. The heat exchanger 19 thus uses the waste heat of the desorber 5 to preheat the washing medium 9 from the absorber 3 before entering the desorber 5.

Within the desorber 5, the carbon dioxide absorbed in the washing medium 9 is thermally desorbed. For the preparation and transfer of the C0 ₂ gas mass flow, a discharge line 21 is connected to the desorber 5. The desorber 5 leaves a largely exempt from other components of C0 ₂ - gas mass flow which a compressor unit is fed to the 30th The compressor unit 30 can consist of a compressor with a number of compressor stages (not shown). The compressor unit 30 may also have a compressor with a corresponding upstream control element (for example a valve) (not shown). The desorber 5 is further connected to a return line 25. The return line 25 is fluidically connected to a feed line 27 of the absorber 3. The scrubbing medium 9 regenerated in the desorber 5 is returned to the absorber 3 via the fluidic connection between the return line 25 and the supply line 27 by means of a pump 29, where it is available for re-absorption of CO ₂ from the flue gas. In addition, the supply line 27 may still have a cooling device 32.

To provide the necessary heat of regeneration for the separation of the carbon dioxide from the washing medium 9, the desorber 5 is connected to a reboiler heat exchanger 31. The loaded washing medium 9 is in this case by steam, which in the

Reboilerwärmetauscher 31 is regenerated. Of the

Reboilerwärmetauscher 31 is heated with process steam 50 from a connected steam power plant, which is not shown here. 2 shows a steam power plant 100 according to the state of

Technology. The steam power plant 100 comprises a steam turbine comprising a high-pressure turbine section 200, a medium-pressure turbine section 300 and a low-pressure turbine section 400, which are connected to one another in a torque-transmitting manner via a common shaft train 500. At the shaft strand 500, a generator, not shown, is arranged.

At a high-pressure steam outlet 900, the steam from the high-pressure turbine part 200 flows to a reheater 110. In the reheater 110, the steam is reheated to a higher temperature. Subsequently, the steam flows into a medium-pressure steam inlet 130 of the medium-pressure turbine section 300.

In the medium-pressure turbine part 300, the steam relaxes, again lowering the temperature of the steam. The medium-pressure turbine part 300 comprises a first flood 140 and a second flood 150. The first flood 140 and the second flood 150 each comprise stages, which are not shown in more detail Guides and blades not shown are formed. The steam flowing into the medium-pressure turbine section 300 is divided into a first partial flow and a second partial flow, the first partial flow flowing through the first flow 140 and the second partial flow flowing in the opposite direction into the second flow 150.

The vapor in the first flood 140 flows into a first turbine outlet conduit 170 via a first mid-pressure turbine outlet 160. The vapor in the second flood 150 flows through a second intermediate-pressure turbine outlet 180 into a second turbine exit conduit 190. Both the first turbine exit conduit 170 and the second turbine exit conduit 190 open into an overflow line 120 symbolized by a horizontal line. The overflow line 120 is fluidically connected to a low-pressure inlet 210 via a low-pressure inlet line 220.

In the first flow 140 and in the second flow 150, a steam trap (not shown in detail) is provided in each case.

Stage a steam extraction line 230 arranged. The steam flowing into the first flow 140 and into the second flow 150 flows, firstly, via the first 170 and the second turbine outlet line 190 to the low-pressure turbine section 400 and, secondly, via the steam extraction line 230 to the first

Reboilerwärmetauscher 31 (FIG 1) as process steam 50 with a process steam pressure.

The steam power plant 100 therefore also has a throttle flap 240 in the overflow line 120. With this throttle valve 240, the pressure of the steam in the overflow 120 can be adjusted. In addition, the pressure of the steam in the steam extraction line 230 depends on the setting of the throttle valve 240. The disadvantage here is that in the Dampfentnähme from the steam extraction line 230, the entire steam flowing through the first turbine outlet line 170 and the second turbine outlet line 190 into the low-pressure turbine section 400 is throttled. The disadvantage However, especially in partial load operation is that the throttling of the remaining steam thermodynamically leads to a high loss. Therefore occur in partial loads partly significant throttle losses, which in turn reduce the efficiency of the system.

The heat supplied to the desorber 5 through the so-called reboiler heat exchanger 31 is transferred by condensation. The required temperature therefore also corresponds to a defined pressure. Depending on the solvent and pressure state in the desorber 5, the required pressure of the steam may vary. In partial load operation of the system, all pressures in the turbines 300,400 behave approximately proportionally proportional to the load, while the process usually requires a constant temperature and thus a constant process steam pressure. It is therefore necessary, especially at partial load, to throttle the pressure via a throttle valve 240 independently of the load to a constant value. According to the invention is now the desorber over the

1, depending on the load, in such a way that the required temperature level of the C0 ₂ deposition process in the desorber 5 (FIG. 1) is shifted by this variation of the desorber pressure. The desorber pressure directly influences the temperature level in the desorber 5 (FIG. 1) via the boiling conditions in the compressor unit 30 (FIG. 1), which in turn determines the CO ₂ solubility equilibrium. As the pressure increases, the temperature level in the desorber 5 (FIG. 1) increases. As a consequence of the temperature increase, a higher process steam temperature is required for a C0 ₂ separation in the desorber 5 (FIG. 1), ie, as the desorber pressure increases, the energy requirement, which must be supplied by the process steam 50 (FIG. 1, 2), increases for desorption of the C0 ₂ . Vice versa, the same can also be transferred to a decreasing pressure, ie as the pressure decreases

Desorberdruck the energy demand, which must be supplied by the process steam 50 (FIG 1,2), for desorption of C0 ₂ decreases. The desorber pressure in the desorber 5 (FIG. 1) is now preferably adapted depending on the load state such that the required process steam pressure corresponds to the natural sliding pressure between the medium-pressure 300 and low-pressure part turbine 400 (FIG. 2). The process steam pressure is therefore not constant, but adapted to the sliding pressure. This eliminates the throttle losses at partial load, which would be more than 10 MW, for example, in an 800 MW plant at half load. The expelled from the detergent C0 ₂ mass flow is therefore removed in each load condition of the compressor unit 30 (FIG 1), which is essential for trouble-free operation. The compressor unit 30 (FIG. 1) conveys the corresponding C0 ₂ mass flow into a large storage volume of constant pressure. The desorber pressure is now set via the admission pressure in the compressor unit 30 (FIG. 1). This is preferably possible via the mode of operation of the compressor unit 30 (FIG. 1). The mode of operation includes, for example, the drive power or the operating point. The operating point can now be changed either via a change in the rotational speed or through the use of a guiding grille (not shown). Vorleitgitter can deflect the flow to the impeller (not shown), for the conversion of flow rate in pressure energy. Depending on the drive power and the operating point of the compressor unit 30 (FIG. 1), this means that a specific pre-pressure, which is also present in the desorber 5 (FIG. That is, if, for example, the process steam pressure changes depending on the load, the desorber pressure is adjusted to this process steam pressure such that sufficient CO ₂ separation takes place in the detergent of the desorber 5 (FIG. 1) despite lower process steam pressure (and therefore process steam temperature). That is, via the reboiler heat exchanger 31 (FIG. 1), the detergent, which is subject to the desorber pressure, is still heated in such a way that a C0 ₂ separation takes place despite, for example, a lower process steam temperature. If the desorber pressure is reduced depending on the load via the compressor unit 30 (FIG a C0 ₂ -Abścutting even at a lower process steam temperature, ie temperature in the reboiler heat exchanger 31 (FIG 1) and thus at lower temperature heating of the detergent in the desorber 5 (FIG 1) instead. The Dersorberdruck can be adjustable either directly via the compressor or else via the control element (not shown). Also, a setting on the compressor, which is supported by the control element, is conceivable. In this case, the form and thus the desorber pressure of a constant-speed C0 ₂ -Verdichtereinheit 30 (FIG 1) by eg adjusting the position of a Vorleitgitters (not shown) are kept constant. The compressor unit 30 (FIG. 1) is therefore operated with a variable pressure and a largely constant inlet volume of C0 ₂ mass flow. As a result, advantageously, the load range of the compressor unit 30 (FIG. 1) can also be expanded. Of course, other means for adjusting the admission pressure and thus the adjusting desorber pressure in the compressor unit 30 (FIG. 1) can also be used. The admission pressure and the process vapor pressure can also be determined via suitably arranged sensors (pressure sensors, temperature sensors). The pre-pressure of the compressor unit 30 (FIG. 1) and thus the desorber pressure can thus be suitably adjusted almost at the same time as the process steam pressure 50 drops. Likewise, the compressor unit 30 (FIG. 1) has a final compressor pressure which is advantageously largely constant in the various load ranges. The invention provides for adjusting the desorber pressure in the desorber 5 (FIG. 1) to the load state of the power plant. As a result, the temperature level of the desorption and thus the required process steam pressure in each load state can be adapted to the prevailing pressure in the line, which is used for branching off the process steam, ie here in the overflow line 120 between medium-pressure 300 and low-pressure turbine 400. If the load in the power plant drops, so does the process vapor pressure and according to the invention the desorber pressure in Desorber 5 off. The process steam pressure is therefore not constant, but adapted to the natural sliding pressure. Also can be dispensed with the throttle valve 240 behind the Prozessdampfentnähme. For example, at a 100% load of the power plant, a process vapor pressure of 5 bar (about 152 ° C) may be present, corresponding to a desorber pressure of 2.3 bar (about 125 ° C) in the detergent, such as an aqueous amine solution. In a lower load range, however, the process steam 50 (FIG. 1, 2) has a process steam pressure of 2.5 bar (approximately 127 ° C.). This corresponds in an aqueous amine solution, for example, 1 bar (about 100 ° C). These are only example values, since, for example, the desorber pressure and the resulting temperature depend on many factors (fill level, detergent, etc.).

FIG. 3 again shows schematically the relationship which should be briefly repeated here again, specifically with reference to the example in which a power plant operated at full load passes into partial load. Of course, the invention is also applicable to a lifting of the load, for example, partial load to full load. If the load in the power plant drops 410, the process steam pressure also drops. Now, the compressor unit 30 (FIG. 1) is set 401 to this new lower pressure, e.g. over the operating point. In front of the compressor unit 30, a pressure matching the process steam pressure is now present 402. As a result, in the desorber 5 403, a desorber pressure 404 matching the process steam pressure is established. The process steam 50 flows 405 with a lower process steam pressure and therefore a lower temperature to the

Reboiler heat exchanger 31. By changing the

Desorber pressure can now take place despite lower temperature good C0 ₂ separation in the desorber 5 (FIG 1). The separated C0 ₂ mass flow now flows 406 to the

Compressor unit 30 (FIG 1).

Claims

claims

1. Plant for the separation of C0 ₂ from a flue gas stream of a load-dependent combustion apparatus comprising a C0 ₂ -Abscheidevorrichtung (1), the C0 is fluidly coupled ₂ -Abscheidevorrichtung (1) with the combustion apparatus, wherein the C0 ₂ -Abscheidevorrichtung (1) a desorber (5) and an absorber (3), the desorber (5) being connected downstream of a compressor unit (30), which is intended to supply one of the C0 ₂ -

Separating device (1) condensed C0 ₂ -conducting gas mass flow,

d a d u r c h e s e n c i n e s, d a s s

the desorber (5) has a desorber pressure which is load-dependent adjustable via the compressor unit (30).

2. Plant according to claim 1,

d a d u r c h e s e n c i n e s, d a s s

the desorber (5) is thermally coupled to a process vapor carrying device, wherein the process steam (50) has a process vapor pressure, and wherein the desorber pressure is adapted to the process vapor pressure.

3. Plant according to claim 2,

d a d u r c h e s e n c i n e s, d a s s

the process vapor pressure is designed as a sliding pressure.

4. Plant according to claim 3 or 2,

d a d u r c h e s e n c i n e s, d a s s

the system has at least two turbines and the turbines are connected to one another via an overflow line (120) and wherein the process steam (50) of the overflow line (120) can be removed.

5. Installation according to one of the preceding claims,

d a d u r c h e s e n c i n e s, d a s s

the incineration plant is a power plant, in particular a gas and steam power plant, which in relation to a load is drivable, wherein the desorber pressure decreases with reduction of the load.

6. Installation according to one of the preceding claims,

d a d u r c h e s e n c i n e s, d a s s

the desorber pressure on the operation of the

Compressor unit (30) is adjustable.

7. Plant according to claim 6,

d a d u r c h e s e n c i n e s, d a s s

the mode of operation comprises at least the drive power and / or the operating point.

8. Installation according to one of the preceding claims 2-4, d a d u r c h e c e n e c e n e, d a s s

arranged by process steam measuring devices of the process vapor pressure is measurable.

9. Installation according to one of the preceding claims 1-8, d a d u r c h e c e n e c i n e t, d a s s

by arranged desorber measuring devices of

Desorber pressure is measurable.

10. Plant according to claim 8 and 9,

d a d u r c h e s e n c i n e s, d a s s

the desorber gauges and process steam gauges return readings and the

Compressor unit (30) is adjustable based on these measurements.

11. Plant according to one of the preceding claims,

d a d u r c h e s e n c i n e s, d a s s

the compressor unit (30) comprises at least one compressor.

12. Plant according to claim 11,

characterized in that the compressor, a control element, in particular a valve, is connected upstream.

13. A method for operating a plant for the deposition of C0 ₂ according to any one of the above claims 1-12, comprising a C0 ₂ -Abscheidevorrichtung (1) with a desorber (5) and an absorber (3), wherein the desorber (5) fluidly a compressor unit (30) is connected downstream,

d a d u r c h e s e n c i n e s, d a s s

the desorber (5) has a desorber pressure which is adjusted load-dependent via the compressor unit (30).

14. A method of operating a plant as claimed in claim 13, wherein said method is operable

the desorber (5) is thermally coupled to a process vapor-conducting device, wherein the process steam has a process vapor pressure, and wherein the desorber pressure is adapted to the process vapor pressure.