Method for generating a deoxidized fluid stream, apparatus for deoxidizing a fluid stream, and use of a heat pump for deoxidizing a fluid stream.

Abstract

The present invention relates to a method for generating a deoxidized fluid stream, comprising a series-connected heat pump for transferring energy from a heat source to a regeneration step. In a second aspect, the present invention relates to an apparatus for generating a deoxidized fluid stream, comprising a series-connected heat pump. In a third aspect, the present invention relates to the use of two series-connected heat pumps for transferring thermal energy from a heat source to a regeneration step in a process for deoxidizing a fluid stream.

Description

[Technical Field]

[0001] The present invention relates to a method for generating a deoxidized fluid stream, which includes a heat pump connected in series to transfer energy from a heat source to a regeneration step.

[0002] In a second aspect, the present invention relates to an apparatus for generating a deoxidized fluid stream, comprising a series-connected heat pump.

[0003] In a third aspect, the present invention relates to the use of two series-connected heat pumps for transferring thermal energy from a heat source to a regeneration step in a process for deoxidizing a fluid stream. [Background technology]

[0004] In light of rising indicators of impending climate change and its serious impact on people worldwide, the United Nations Sustainable Development Goals (SDGs) recognize the need to take action on climate change as one of its 17 Sustainable Development Goals. One of the 17 goals is to incorporate climate change measures into national policies, strategies, and plans. The European Union has launched a series of climate change policy initiatives with the aim of achieving climate neutrality for the European Union by 2050. For a more direct effect, the target for reducing greenhouse gas emissions has been raised to approximately 50% of 1990 levels, with the goal of achieving net-zero greenhouse gas emissions by 2050. Similar initiatives and incentives for climate protection are being implemented by other governments.

[0005] Carbon dioxide is one of the most abundant greenhouse gases in the atmosphere. Greenhouse gases are gases that absorb and emit infrared radiation in the wavelength range emitted by the Earth, and therefore contribute to global warming. The concentration of CO2 in the atmosphere has risen from approximately 280 ppm in the pre-industrial era around 1750 to approximately 421 ppm in 2022. About two-thirds of all carbon dioxide emissions come from the burning of fossil fuels.

[0006] Most climate change countermeasures require massive financial investment and take several years or even decades to implement.

[0007] Carbon capture and storage (CCS) or carbon capture, utilization, and storage (CCUS) are readily available and mature technologies that can be implemented on a large scale and in a short timescale, and therefore have a more direct impact on climate change. Carbon dioxide can be captured directly from industrial sources such as cement production, natural gas processing, and ammonia and hydrogen production, or from power plants powered by fossil fuels or biomass fuels. Currently, the carbon capture rate from exhaust gases of carbon-based fuels is 80-95%.

[0008] The captured carbon dioxide can be removed from the atmosphere by carbon sequestration or carbon storage in suitable geological formations such as depleted oil reservoirs, gas reservoirs, tunnels, and saline or other rock formations. Before transporting the carbon dioxide to its final storage location and injecting it underground, it is typically compressed to a high pressure of approximately 100 bar. Other uses of captured carbon dioxide include enhanced oil recovery or conversion into fuel, cement, minerals, or chemicals.

[0009] Currently, one of the most mature methods for carbon capture is amine gas treatment. Amine gas treatment is a process in which acidic gases (sour gases) such as carbon dioxide or hydrogen sulfide are removed from a feed gas stream by absorption in an amine solvent. A typical acid gas removal unit (AGRU) comprises an absorption tower, a regeneration tower, and auxiliary equipment. In the absorption tower, the amine flowing downward absorbs the acidic components of the feed gas, yielding a sweetened gas or sweet gas stream and an amine solution ("rich amine") that has partially absorbed the acidic components. The rich amine solution is then fed to a regeneration tower or a desorption tower, where it is heated to desorb or flash the desorbed acidic gas at the top of the tower, producing a regenerated amine solution ("lean amine") which can be recycled back into the absorption tower. The desorbed CO2 is then compressed, dried, optionally refrigerated, and transported to its storage location.

[0010] Amine gas treatment is a relatively energy-intensive process. It is estimated that up to 40 percent of the energy produced at a power plant is consumed by carbon capture and sequestration. This energy loss is divided into approximately 60% in the amine gas treatment process and 30% in carbon dioxide compression. The most energy-intensive part of amine gas treatment is the release of captured carbon dioxide in the decontamination tower. The temperature in the absorption tower is typically around 30-70°C, but the temperature required to release carbon dioxide is usually in the range of 100-150°C. The energy required to heat the rich amine is usually supplied by transferring heat from high-temperature process steam to the rich amine in the regeneration tower.

[0011] Process steam can be produced in combined cycle gas power plants. In such cases, steam production from power generation can be incorporated into the amine gas treatment process. However, steam integration with existing steam sources is not always possible in all AGRUs, in which case the required steam must be supplied by a standalone process steam production process, such as a steam boiler.

[0012] Therefore, there are numerous trends addressing the need to reduce the energy consumption of amine gas treatment units.

[0013] One possible strategy for reducing energy consumption is to improve the cycle capacity of the amine solvent and attempt to reduce the energy required to regenerate the amine solvent. However, solvent development is quite costly and time-consuming, often requiring the use of specialized, expensive solvent systems, which further increases operating costs.

[0014] Another strategy employed to reduce the energy consumption of amine gas processing units is to transfer heat from a heat source with a higher temperature to a location with a lower temperature within the gas processing unit.

[0015] The most prominent example of such heat transfer means is the so-called direct-to-direction heat exchanger placed between the regeneration tower and the absorption tower, in which the low-temperature rich amine from the absorption tower is heated by the high-temperature lean amine exiting the regeneration tower before being supplied to the regeneration tower. However, indirect heat exchange by direct-to-direction heat exchangers is usually insufficient to supply most of the energy required to operate the dissipation tower.

[0016] U.S. Patent No. 3,823,222 teaches that the energy contained in the high-temperature feed gas deoxidized in the AGRU is used to heat the reboiler of the regenerator in a separate boiler, which can be used for steam venting in the regenerator.

[0017] U.S. Patent No. 3101996 also teaches that a high-temperature fluid stream, such as synthesis gas or hydrogen gas obtained from an aqueous shift reaction, can be used to generate steam in a separate boiler that can be used to heat an amine desorption column.

[0018] International Publication No. 2007 / 012143 discloses two separate cooling stages for cooling high-temperature exhaust gas from a steam turbine before amine gas treatment. In the first stage, the exhaust gas is cooled in a heat exchanger by indirect heat exchange with a fluid used to heat a radiating tower. In the second stage, the exhaust gas is cooled by transferring thermal energy to a heat pump system used to heat the radiating tower. The heat pump system may also be supplemented by heat regenerated in other heat sources, such as a CO2 compression stage.

[0019] The use of heat pumps to transfer energy from process units with higher thermal energy levels to process units with lower thermal energy levels is not limited to high-temperature supply gases. Many heat sources in amine gas processing processes have been proposed for use with heat pumps.

[0020] In International Publication Nos. 2010 / 097047 and 2011 / 122525, the heat of absorption in the absorption tower is used as a heat source for a heat pump to heat the rich amine solution.

[0021] Japanese Patent Publication No. 2015-131735 describes the use of an intercooler loop in an absorption tower as a heat source for a heat pump to heat the diffusion tower.

[0022] International Publication No. 2007 / 081214 and Specification No. CN114405258 disclose the use of condensation energy generated in the condenser of a radiation tower as a heat source.

[0023] International Publication No. 2012 / 058558 describes using the thermal energy of the radiated gas in a top condenser as a heat source for a heat pump. Although the disclosure is limited to the removal of SO2 from a gaseous mixture, the principle can theoretically be applied to the removal of CO2.

[0024] Japanese Patent Publication No. 2010-088982 discloses the use of compression heat generated in a compressor used to compress carbon dioxide to high pressure to heat a rich amine solution.

[0025] Japanese Patent Publication No. 2015-131736 essentially teaches a replacement for conventional DC-AC heat exchangers used to transfer heat from a high-temperature lean amine solution exiting a decontamination tower to a rich amine solution entering the decontamination tower, using a heat pump.

[0026] French Patent Application Publication No. 2968574 discloses the use of multiple heat sources for a heat pump, including a top condenser for a decontamination column, a lean amine solution exiting an absorption column, and a top condenser for an absorption column used to remove water vapor from a sweet gas.

[0027] Similarly, Specification CN10289584 mentions using the lean amine solution exiting the decontamination column and the top condenser of the decontamination column as a heat source for a heat pump.

[0028] It is also possible to use a heat source outside of the amine gas treatment process.

[0029] Specification No. CN112126477 discloses the use of blast furnace slag wash water as a heat source for heating a radiating tower using a heat pump.

[0030] The energy contained in the various heat sources disclosed is usually not large enough to provide all the energy required in the dissipation step. Therefore, it is necessary to utilize multiple heat sources and thus the use of two or more heat pumps. Using several heat pumps increases the capital cost of the amine gas treatment unit.

[0031] U.S. Patent Application Publication No. 2013 / 056676 relates to a polarity swing-assisted regeneration (PSAR) method for improving the efficiency of releasing chemically bound gases from switchable ionic liquids (SWILs). SWIL regeneration involves adding a certain amount of a nonpolar organic compound as a poor solvent to destabilize the SWIL, which helps release the chemically bound gases. PSAR increases the gas release rate by reducing the amount of gas dissolved in the SWIL at a given temperature compared to heating in the absence of a poor solvent. In some embodiments, regeneration involves using a heat pump to transfer heat to one or more of the following: condenser, evaporator, absorption tower, cooler, separator, regeneration tower, or reboiler.

[0032] International Publication No. 2023 / 057372 relates to a gas recovery system in which gas is recovered by a liquid adsorbent. The adsorbent is recycled between a first reactor system and a second reactor system. In the first reactor system, the adsorbent recovers gas from the gas stream in an exothermic process. In the second reactor system, the adsorbent is regenerated and the recovered gas is released in an endothermic process. The second gas recovery system may operate at a lower pressure than the first gas recovery system. Furthermore, it is disclosed that several different configurations of heat pump integration may also be used within the gas recovery system as an efficient means for electrifying the system.

[0033] While many disclosures focus on thermal integration in gas processing, there is still a need for thermal integration solutions that can supply most or all of the energy required for regeneration towers without dramatically increasing capital costs. [Overview of the project] [Problems that the invention aims to solve]

[0034] Therefore, the fundamental problem underlying the present invention is to provide a way to reasonably limit additional investment in plant infrastructure while reducing the energy demand of gas processing units using liquid absorbents. A further fundamental problem underlying the present invention is to reduce corrosion and contamination in equipment in contact with the fluid stream. Another fundamental problem underlying the present invention is to avoid the need for expensive equipment required to transport the gaseous stream. In addition, an object of the present invention is to electrify the steam generation required for the regeneration of the rich absorbent solution, potentially decoupling steam generation from the need for power generation in a power plant or to provide a standalone steam generator. A further object of the present invention is to reduce the energy demand for steam generation required in the regeneration step. Yet another object of the present invention is to provide a flexible process that allows for variations in the capacity of the AGRU. [Means for solving the problem]

[0035] First aspect - Method for generating a deoxidized fluid stream by a heat transfer process, comprising two or more heat pumps In a first aspect, the present invention relates to a method for generating a deoxidized fluid stream containing at least one acidic gas, a) A heat energy transfer step in which thermal energy is transferred from heat stream HS1 to regenerated step c) to obtain heat stream HS2 having reduced thermal energy compared to heat stream HS1, b) An absorption step in which the fluid stream FS2 is brought into contact with the absorbent A1 in the absorption tower to obtain the absorbent A2 that has absorbed the acidic gas and the fluid stream that has been at least partially deoxidized, c) A regeneration step in which at least a portion of the absorbed absorbent A2 obtained from step b) is regenerated in a regeneration tower to obtain a gaseous stream GS containing at least partially regenerated absorbent A3 and at least one acidic gas, d) A recycling step in which at least a substream of the recycled absorbent A3 from step c) is recycled to the absorption step b) In a method including, The present invention relates to a method wherein the thermal energy transfer step a) includes two or more heat pumps connected in series.

[0036] heat source The method of the present invention includes transferring thermal energy from the heat stream HS1 to a regeneration step c) to obtain a heat stream HS2 having reduced thermal energy compared to stream HS1.

[0037] The heat stream HS1 is preferably generated from a heat source HS.

[0038] The heat source HS can be any heat source from the gas processing process or an external heat source outside the gas processing process.

[0039] The heat source HS can be the absorbed heat generated in the absorption tower, and this absorbed heat can be utilized by an intercooler or by integrating a heat exchanger with the absorption tower. In this case, stream HS1 is the high-temperature stream leaving the absorption tower, and stream HS2 is the cooled stream entering the absorption tower.

[0040] Another heat source HS is the heat absorbed by the rescrubbing zone at the top of the absorption tower, if the rescrubbing zone is equipped with a pump and cooler. In this case, stream HS1 is the hot stream leaving the rescrubbing zone of the regenerating tower, and stream HS2 is the cooled stream entering the regenerating tower.

[0041] Another heat source HS is the heat of condensation of condensates at the top of the absorption or regeneration tower. In this case, stream HS1 is a stream of warm cooling medium leaving a backwash zone at the top of the absorption or regeneration tower, surrounded by a condenser or cooled pump, and stream HS2 is a stream of cooled cooling medium entering this device.

[0042] Another heat source HS is the heat of compression generated in the compression step when compressing the gaseous stream GS, as will be further explained below. In this case, stream HS1 is the compressed stream GS, and stream HS2 is the cooled compressed stream GS.

[0043] Fluid Stream FS1 In a preferred embodiment of the present invention, stream HS1 is a fluid stream FS1.

[0044] The fluid stream FS1 into which thermal energy is transferred in regeneration step c) can be any fluid stream containing at least one type of acidic gas.

[0045] Preferably, the fluid stream FS1 contains CO2. In addition to CO2, other acidic gases such as H2S, CS2, or COS may be present. In addition, sulfur and nitrogen oxides SO2 may be present. x and NO x It is also possible that such a thing exists.

[0046] The acidic gas content in the fluid stream FS1 is generally 0.01% to 40% by volume, preferably 2% to 30% by volume, and more preferably 3% to 25% by volume.

[0047] The fluid stream FS1 introduced into the process of the present invention may contain water. The water content in the fluid stream is generally in the range of greater than 0 volume% to the water content corresponding to the saturation concentration of water in the fluid stream under the applied pressure and temperature conditions.

[0048] The temperature of the fluid stream FS1 is preferably in the range of 40 to 300°C, more preferably 50 to 250°C, and most preferably 60 to 200°C. The method according to the present invention is particularly suitable for exhaust gases having low temperatures in the range of 60 to 250°C, because the thermal energy contained in such low-temperature fluid gas stream FS1 can be transferred to the energy level required in regeneration step c) by combining two or more heat pumps in series.

[0049] The pressure in the fluid stream FS1 typically depends on the source of the fluid stream FS1, as will be further outlined below.

[0050] Preferably, the fluid stream 1 is exhaust gas.

[0051] The exhaust gas is preferably obtained by the combustion of fossil fuels such as coal, natural gas, and petroleum, or carbon-based fuels such as biomass raw materials derived from plants, algae, or animals.

[0052] Such combustion processes can occur in power plants or power plants. Preferably, the exhaust gas source is from the combustion of coal, natural gas, petroleum, biofuels such as bioethanol or biodiesel, or biomass derived from forestry, agriculture, or aquaculture.

[0053] Preferably, the fluid stream FS1 is exhaust gas from a steam turbine in a steam power plant where a generator is driven by steam obtained from the combustion of a carbon-based fuel.

[0054] Most preferably, the fluid stream FS1 is the exhaust gas from a steam turbine of a gas-fired power plant designed as a simple-cycle gas turbine or a combined-cycle power plant.

[0055] Before being used in the method of the present invention, the exhaust gas stream FS1 is optionally treated to remove particulate matter by filtration or electrostatic precipitation.

[0056] In a preferred embodiment, the exhaust gas stream FS1 is desulfurized by removing sulfur dioxide. An overview of the exhaust gas desulfurization method is described in the Wikipedia article "Flue-gas desulfurization" (https: / / en.wikipedia.org / wiki / Flue-gas_desulfurization).

[0057] The fluid exhaust gas stream FS1 is preferably, CO2: 1-25% by volume, preferably 5-20% by volume. H2O: 3-50% by volume, preferably 5-30% by volume, O2: 0.1-16% by volume, preferably 1-10% by volume Includes.

[0058] In addition, even after the exhaust gas desulfurization step, the exhaust gas contains small amounts of other gases, especially nitrogen oxides (NOx). x ) and sulfur oxides (SO x ) includes.

[0059] The exhaust gas also contains nitrogen in such quantities that the sum of the volume fractions of each component present in the exhaust gas equals a value of 1 (or 100 vol%). Typically, the nitrogen content ranges from 40 to 95 vol%.

[0060] The fluid stream FS1 is preferably in a gaseous state. Depending on the temperature and moisture content, the fluid stream FS1 may also contain condensed water and acid.

[0061] When the fluid stream is exhaust gas, the pressure of the fluid stream FS1 entering the cooling step is typically atmospheric pressure, preferably in the range of 0.7 to 1.5 bar, more preferably 0.8 to 1.3 bar, and more preferably 0.9 to 1.2 bar.

[0062] The temperature of the fluid exhaust gas stream FS1 is preferably in the range of 50 to 300°C, preferably 60 to 250°C, and most preferably 60 to 200°C.

[0063] Fluid stream FS1 can also be an off-gas stream where CO2 is released in industrial processes that release CO2 from chemical reactions. Examples of such industrial process streams include CO2 emissions from the thermal decomposition of limestone and dolomite in cement production, CO2 emissions from the use of carbon as a reducing agent in the commercial production of metals from ore (e.g., iron production in blast furnaces), or CO2 emissions from biomass fermentation (e.g., to convert sugars into alcohol).

[0064] In a preferred embodiment, the fluid stream FS1 is a stream that combines exhaust gas from a carbon-fuel combustion process with CO2 emissions from a CO2-generating industrial process such as a cement manufacturing process, a metal manufacturing process, or a fermentation process.

[0065] In a further preferred embodiment, the fluid stream FS1 is an exhaust gas stream arriving from the furnace of a pyrolysis unit, in which hydrocarbons such as petroleum fractions, naphtha, and liquefied natural gas (methane, ethane, and propane, etc.) are decomposed thermally or using a catalyst to obtain shorter-chain molecules or recombined molecules having different structures. Preferably, the fluid stream FS1 is the exhaust gas from a steam cracking furnace.

[0066] Alternatively, the fluid stream FS1 may be crude synthesis gas. Such synthesis gas (or "syngas") can be obtained from the gasification of coal or mineral oil, steam reforming of mineral oil distillates, steam reforming of methane, or autothermal reforming of natural gas. Synthesis gas typically contains hydrogen, carbon monoxide, and some carbon dioxide, as well as water.

[0067] A preferred fluid stream FS1 is the fluid stream exiting the aqueous shift reactor in the synthesis gas generation. The aqueous shift reaction is preferably carried out as a high-temperature shift conversion (HTSC) at a temperature of about 300–450°C, a medium-temperature shift conversion (MTSC) at a temperature of about 150–350°C, a low-temperature shift conversion (LTSC) at a temperature of about 150–250°C, or a sour gas shift conversion (SGS) at a temperature of about 200–300°C.

[0068] When the fluid stream is synthesis gas, the total pressure is typically in the range of 5 to 120 bar, preferably 10 to 100 bar, and more preferably 10 to 60 bar.

[0069] Step a) Heat energy transfer step from FS1 to regeneration step c) Step heat pump The method of the present invention includes a heat energy transfer step a) in which thermal energy is transferred from heat stream HS1 to regeneration step c) to obtain heat stream HS2 having reduced thermal energy compared to heat stream HS1.

[0070] The thermal energy transfer step a) includes at least two (or more) heat pumps connected in series.

[0071] The heat pump can be either an open-loop heat pump or a closed-loop heat pump.

[0072] In a closed-loop heat pump, the working fluid or heat transfer fluid is essentially contained within a closed loop; that is, it is essentially in a steady state and is not in contact with an external heat sink or external power source. In an open-loop heat pump, the working fluid or heat transfer fluid is not essentially in a closed loop.

[0073] Within the scope of the present invention, a heat pump is a device for transferring heat from a heat source at a certain temperature to a heat sink at a higher temperature. An open-loop heat pump is typically, - A step of transferring thermal energy from a heat source to a heat transfer material, typically by a heat exchanger, wherein the heat exchanger is usually designed as an evaporator for at least a portion of the heat transfer material in a heat pump. - A step of compressing a partially gasified heat transfer material in one or more compression steps, usually involving one or more compressors, to raise the temperature of the heat transfer material, - Typically, the heat pump transfers thermal energy from the compressed heat transfer material to the heat sink by a separate heat exchanger that acts as a condenser for the heat transfer material, at least partially in a gaseous state. Includes.

[0074] Open-loop heat pumps have the advantage of being able to utilize media from various sources, particularly water, which is usually already present in amine gas treatment processes.

[0075] A closed-loop heat pump typically has a heat transfer medium in a closed loop between the heat source and the heat sink. This is usually accomplished by an additional recycling step for the heat transfer medium, such as a recycling step R1 or R2 for the heat pump HP1 or HP2, which will be further described below.

[0076] Within the scope of the meaning of the present invention, the requirement for using two heat pumps connected in series is that the compressed heat transfer medium of heat pump HP1 functions as a heat source for the heat transfer medium stream of heat pump HP2, and heat pump HP2 functions as a heat sink for heat pump HP1, and the thermal energy from the heat transfer medium stream HTMS of heat pump HP1 to the heat transfer medium stream of heat pump HP2 is affected via a common heat exchanger HE2. In other words, the heat exchanger HE2 functions as a condenser for the heat transfer material of heat pump HP1 and an evaporator for the heat transfer material of heat pump HP2.

[0077] Using two heat pumps connected in series has the advantage that the thermal energy from the heat stream HS1 can be raised to a level where steam can be generated in heat pump HP2, which can then be used to transfer the heat to regeneration step c). Thus, the stream generated in heat pump HP2 can substantially replace the process steam that is typically required as a heat source in regeneration step c). Therefore, using two heat pumps in series can replace the need to install a separate process steam generation process at the site of the acid gas removal unit, or the need for a steam turbine, such as a back pressure turbine or extraction condensate turbine, to generate process steam in a decarbonized power plant. Thus, the present invention is particularly useful when process steam is not readily available at the site of the acid gas removal unit. However, even where process steam is readily available, the method according to the present invention may be useful as an alternative method for generating process steam, as it allows potentially limited process steam resources to be used for other purposes, or reduces power plant power losses associated with process steam generation. In addition, the method of the present invention is an interesting alternative in the design of new power plants coupled with acid gas removal units for carbon capture, as it can reduce the need to divert energy for steam generation to power the recycling step. Furthermore, the method of the present invention is a useful method for electrifying steam generation so that the steam required in the amine gas treatment process can be supplied by "green" electricity from renewable resources.

[0078] In a preferred embodiment, at least one, preferably both, of the heat pumps includes a step of expanding the compressed heat transfer medium stream after the transfer of thermal energy to the heat sink. These recycling steps R1 or R2 (described later) allow for the recycling of the heat transfer material to the transfer step a), significantly reducing the need to replenish the heat transfer material and thus leading to further improvements in the efficiency of the method. This method is particularly advantageous when using heat transfer materials that have harmful effects on the environment, in which case it is desirable to house these materials in a closed cycle.

[0079] In a more preferred embodiment, at least one of the heat pumps connected in series, preferably the last heat pump, operates as an open-loop heat pump, in particular when the heat transfer material HTM used in the last heat pump is water. The capital cost required for this alternative is relatively small. Due to having fewer components, open-loop heat pumps are simpler and have lower operating and maintenance costs.

[0080] Heat transfer from the heat stream HS1 to the heat transfer material stream HTMS1 of the first heat pump HP1 can occur directly in the heat exchanger HE1 by exchanging thermal energy from the heat stream HS1 to the heat transfer material stream HTMS1.

[0081] In a preferred embodiment, heat transfer from the heat stream HS1 to the heat transfer material stream HTMS1 of the first heat pump HP1 may occur indirectly via an intermediate cooling step. In the intermediate cooling step, thermal energy from the heat stream HS1 is transferred to the cooling medium stream CMS1 to obtain a cooled heat stream HS2 and a cooling medium stream CMS2 having increased thermal energy compared to the cooling medium stream CMS1. The thermal energy is then further transferred from the cooling medium stream CMS2 to the heat transfer material stream HTMS1 of the first heat pump HP1. Heat transfer from the cooling step is typically influenced by an additional heat exchanger HE-C, which is preferably a gas-liquid heat exchanger when the heat stream HS1 is a fluid stream FS1. Heat transfer via the additional cooling step preferably allows for the direct transfer of thermal energy to the cooling medium stream CMS1 by using a direct contact cooler (DCC) as the heat exchanger. Direct contact means that the streams are in direct physical contact with each other rather than being separated by a partition (direct heat exchange).

[0082] Direct heat exchange is in contrast to indirect heat transfer, where the heat stream HS1 and the cooling medium stream CMS1 do not come into direct contact, and heat exchange occurs indirectly or transiently through a partition wall. Direct heat exchange has the advantage of increasing the exchange area between the two streams HS1 and CMS1, thereby reducing thermal resistance and maximizing thermal efficiency. In addition, direct heat exchangers generally have lower operating and capital costs than indirect heat exchangers due to their high heat transfer rate per unit volume and because contamination and corrosion are not usually a problem. Furthermore, expensive equipment such as blowers or fans required to transport fluid streams such as FS1 and FS2 in indirect gas-liquid heat exchangers are usually not required in direct heat exchangers because the pressure drop is smaller compared to indirect heat exchangers.

[0083] In a preferred embodiment of the present invention, the heat transfer step a) of the present invention is performed directly from the heat stream HS1 and the heat transfer material HTM1 of the heat pump 1, preferably, 1) In the heat exchanger HE-1 of the first heat pump HP1, thermal energy is transferred from the heat stream HS1 to the heat transfer medium stream HTMS1 of the heat transfer material HTM1 to obtain a heat transfer medium stream HTMS2 having increased thermal energy compared to the heat transfer medium stream HTMS1, 2) The step of compressing the heat transfer medium stream HTMS2 in the first heat pump HP1 to obtain a heat transfer medium stream HTMS3 having a higher pressure than the heat transfer medium stream HTMS2, 3) In the heat exchanger HE-2 of the second heat pump HP2, thermal energy is transferred from the heat transfer medium stream HTMS3 of the first heat pump HP1 to the second heat transfer medium stream SHTMS1 of the second heat transfer material HTM2, thereby obtaining a second heat transfer medium stream SHTMS2 having increased thermal energy compared to the second heat transfer medium stream SHTMS1, and a heat transfer medium stream HTMS4 having a decreased thermal energy content compared to the heat transfer medium stream HTMS3. 4) The step of compressing the second heat transfer medium stream SHTMS2 in the second heat pump HP2 to obtain a second heat transfer medium stream SHTMS3 having a higher pressure than the second heat transfer medium stream SHTMS2, 5) Transferring thermal energy from the second heat transfer medium stream SHTMS3 of the second heat pump HP2 to regeneration step c) to obtain a second heat transfer medium stream SHTMS4 having a reduced thermal energy content compared to SHTMS3. Includes.

[0084] In a further preferred embodiment, step 1) of the method according to the present invention proceeds indirectly via an intermediate cooling step, 1a) Transferring thermal energy from FS1 to the cooling medium stream CMS1 to obtain a) a fluid stream FS2 having a reduced thermal energy content compared to FS1, and b) a cooling medium stream CMS2 having an increased thermal energy content compared to CMS1. 1b) Transfer at least a portion of the thermal energy contained in the cooling medium CMS2 to the heat transfer medium stream HTMS1, thereby obtaining a heat transfer medium stream HTMS2 having increased thermal energy compared to HTMS1, and a cooling medium stream having decreased thermal energy compared to CMS2, which is at least partially recycled back to step 1a) as CMS1. Includes.

[0085] In a more preferred embodiment, the method of the present invention also includes the following recycling steps, namely, R1) The heat transfer material stream HTMS4 obtained in step 3) is expanded to obtain a heat transfer medium stream HTMS5 having a lower pressure compared to the heat transfer material stream HTMS4, which is then at least partially recycled back to step 1) as the heat transfer material stream HTMS1. R2) The second heat transfer material stream SHTMS4 obtained in step 5) is expanded to obtain a second heat transfer medium stream SHTMS5 which has a reduced pressure compared to the second heat transfer material stream SHTMS4 and is at least partially recycled in step 3) as the second heat transfer material stream SHTMS1. This includes one or both of the above.

[0086] Step 1) Heat transfer from heat stream HS1 to heat pump 1 In step 1) of a preferred embodiment of the present invention, thermal energy is transferred from the heat stream HS1 to the heat transfer medium stream HTMS1 of the first heat pump HP1 to obtain a heat transfer medium stream HTMS2 having increased thermal energy compared to the heat transfer medium stream HTMS1. Furthermore, a cooled heat stream HS2 having lower thermal energy compared to the heat stream HS1 is obtained.

[0087] As described above, the heat pump HP1 is a suitable device for transferring thermal energy from the heat stream HS1, which is the heat source, to the heat transfer medium stream HTMS1 of the heat pump HP1. As described above, the heat pump HP1 may be an open-loop heat pump or a closed-loop heat pump.

[0088] The heat pump HP1 is preferably, - A heat exchanger HE1 transfers thermal energy from a heat stream HS1 to a heat transfer medium stream HTMS1 of a heat pump HP to obtain a heat transfer material stream HTMS2 having increased thermal energy compared to the heat transfer medium stream HTMS1, - One or more compressors for compressing a heat transfer material stream HTMS2 in one or more compression steps to obtain a heat transfer material stream HTMS3 having a higher pressure compared to the heat transfer material stream HTMS2, - Heat exchanger HE2 to transfer thermal energy from the heat transfer material stream HTMS3 of the first heat pump to the second heat transfer material stream SHTMS1 of the second heat pump HP2, thereby obtaining the heat transfer material stream HTMS4 of the first heat pump HP1 having reduced thermal energy compared to the heat transfer material stream HTMS3. It is equipped with.

[0089] In addition, if HP1 is a closed-loop heat pump, HP1 is preferably, - One or more inflation devices to inflate the heat transfer material stream HTMS4 to obtain a heat transfer material stream HTMS5 having a reduced pressure compared to the heat transfer material stream HTMS4. It is equipped with.

[0090] Heat transfer material HTM1 The heat transfer material HTM1 is the working fluid used in the heat pump HP1 to transport thermal energy from heat exchanger HE1 to heat exchanger HE2.

[0091] Preferably, the heat transfer material HTM1 can undergo at least a partial phase transition from liquid to gaseous state during the transfer of thermal energy in the heat exchanger HE1.

[0092] Preferably, the heat transfer material HTM1 may also undergo at least a partial phase transition from a gaseous to a liquid state when transferring thermal energy from the heat exchanger HE2 to the second heat pump HP2.

[0093] Therefore, the heat transfer material HTM1 is preferably selected from the group of refrigerants consisting of ammonia, butane, R1233zd(e), R1224yd(z), air, CO2, water, chlorofluorocarbons, hydrochlorofluorocarbons, hydrofluorocarbons, hydrofluoroolefins, hydrochlorofluoroolefins, hydrocarbons, perfluoro(2-methyl-3-pentanone), and mixtures of two or more of these. Suitable refrigerants are known to those skilled in the art and are disclosed, for example, in C. Arpagaus et al. (C. Arpagaus et al., Energy 152 (2018), pages 985 to 1010).

[0094] Heat transfer material streams 1-5 are streams of heat transfer material 1 at different stages of the heat pump HP1. - The heat transfer material stream HTMS1 is the stream of heat transfer material HTM1 that enters step 1). - The heat transfer material stream HTMS2 is a stream of heat transfer material HTM1 that exits step 1) and enters step 2) after being compressed. - The heat transfer material stream HTMS3 is a stream of heat transfer material HTM1 that exits compression step 2) and enters step 3). - The heat transfer material stream HTMS4 is a stream of heat transfer material HTM1 that can exit step 3) and optionally enter the recycling step R1). - The heat transfer material stream HTMS5 is the stream of heat transfer material HTM1 exiting the recycling step R1).

[0095] Direct heat transfer from HS1 to HTMS1 via heat exchanger HE1 In step 1) of the present invention, 1) thermal energy from the heat stream HS1 is transferred to the heat transfer medium stream HTMS1 of the first heat pump HP1 to obtain a heat transfer medium stream HTMS2 having increased thermal energy compared to the heat transfer medium stream HTMS1. Also, a cooled heat stream HS2 having lower thermal energy compared to the heat stream HS1 is obtained.

[0096] In a preferred embodiment of the present invention, the thermal energy of the heat stream HS1 is directly transferred to the heat transfer material stream HTMS1 of the heat pump HP1.

[0097] The transfer of thermal energy from the heat stream HS1 to the heat transfer material stream HTMS1 is typically affected by the heat exchanger HE1.

[0098] The exchanger HE1 is a device typically used to transfer thermal energy in the form of heat between a heat stream HS1 and a heat transfer medium stream HTMS1 to obtain a heat transfer medium stream HTMS2 having increased thermal energy compared to the heat transfer medium HTMS1, and a heat stream HS2 having decreased thermal energy compared to the heat stream HS1.

[0099] In a preferred embodiment, the heat exchanger HE1 is an indirect heat exchanger in which heat is transferred between the heat stream HS1 and the heat transfer medium stream HTMS1 indirectly or transiently through a partition wall, or by moving in and out of the wall, without any physical contact or mass transfer between the two streams (indirect heat exchange).

[0100] When the heat exchanger HE1 is an indirect heat exchanger, HE1 typically - an inlet for a heat stream HS1 having a pressure p HS1 and a temperature T HS1 upon entering the inlet, and - an outlet for a heat stream HS2 having a pressure p HS2 and a temperature T HS2 upon exiting the outlet, and - an inlet for a heat transfer medium stream HTMS1 having a pressure p HTMS1 and a temperature T HTMS1 upon entering the inlet, and - an outlet for a heat stream HS2 having a pressure p HTMS2 and a temperature T HTMS2 upon exiting the outlet and is provided with.

[0101] Preferably, the heat exchanger HE1 is an indirect gas-liquid heat exchanger in which heat is transferred from the gaseous heat stream HS1 to the liquid heat transfer material stream HTMS1.

[0102] Preferably, the gas-liquid heat exchanger is an extended surface heat exchanger as described in Chapter 2.1.3 of the article "Heat Exchangers, 1. Fundamentals and General Design Methodology" in Ullmann's Encyclopedia of Industrial Chemistry (https: / / doi.org / 10.1002 / 14356007.b03_02.pub2), more preferably a plate fin heat exchanger such as those described in Chapter 2.1.3.1 of the same document, or a finned tube heat exchanger such as those described in Chapter 2.1.3.2 of the same document.

[0103] The heat exchanger HE1 is preferably designed such that the following requirements are met. - The temperature T HTMS1 is preferably lower than T FS1 by preferably 1 to 100 K, more preferably 2 to 60 K, and most preferably 5 to 30 K. - Temperature T FS2 The temperature is preferably in the range of 20 to 80°C, more preferably in the range of 25 to 70°C, and most preferably in the range of 30 to 60°C. - The heat transfer material stream HTMS1 undergoes at least a partial phase transition from liquid to gaseous state in the heat exchanger HE1.

[0104] Typically, pressure drops occur in indirect gas-liquid heat exchangers. To transport a gaseous heat stream HS2, such as FS2, from the heat exchanger HE1 to the absorption tower and overcome the pressure drop in the indirect heat exchanger HE1, an additional blower or fan is recommended behind the outlet of the heat stream HS2.

[0105] In a preferred embodiment, the heat exchanger HE1 is designed to transfer more energy than is required in the regeneration step. In this case, the excess energy can preferably be used to supply excess steam, which can then be moved to the field steam network and distributed to other field processes or process steps that may require such energy.

[0106] Alternatively, the heat exchanger HE1 can be designed so that less energy is transferred than is required in the regeneration step. In this case, it is preferable to provide additional energy, preferably steam, to the regeneration step from another source, for example, an on-site steam network that distributes steam from another steam source.

[0107] If the heat stream HS1 is a fluid stream FS1, the heat exchanger HE1 is preferably designed such that the transferred thermal energy is just enough to provide the thermal energy required in regeneration step c). If the heat stream FS1 contains more thermal energy or heat than is required to be transported by the heat pump to regeneration step c), only the energy required in regeneration step c) is transferred to the heat exchanger HE1. If, after the transfer of the heat or thermal energy required for regeneration step c), the fluid stream FS2 is too hot to enter the absorption tower, the fluid stream FS2 leaving the heat exchanger HE1 is cooled in one or more additional heat exchangers before entering the absorption tower, so that the fluid stream FS2 has a temperature in the range of 20-80°C, more preferably 25-70°C, and most preferably 30-60°C at the inlet of the absorption tower.

[0108] Such additional heat exchangers are classic heat exchangers such as plate heat exchangers, shell-and-tube heat exchangers, air coolers, or water coolers such as cooling towers. An overview of cooling towers that can be used to further cool the fluid stream FS2 is provided in the Wikipedia article "Cooling Towers" (https: / / en.wikipedia.org / wiki / Cooling_tower#). This embodiment has the advantage that the temperature of the fluid stream FS2 at the absorption tower inlet can be adjusted independently of the operation of the heat pump HP1.

[0109] Indirect heat exchange from HS1 to HTMS1 via an intermediate cooling step In a preferred embodiment of the present invention, the heat transfer step 1) involves transferring thermal energy from the heat stream HS1 to the heat transfer medium stream HTMS1 of the first heat pump HP1 to obtain a heat transfer medium stream HTMS2 having increased thermal energy compared to the heat transfer medium stream HTMS1. 1a) Transferring thermal energy from heat stream HS1 to cooling medium stream CMS1 to obtain a) heat stream HS2 having a reduced thermal energy content compared to heat stream HS1, and b) cooling medium stream CMS2 having an increased thermal energy content compared to CMS1, 1b) Transfer at least a portion of the thermal energy contained in the cooling medium CMS2 to the heat transfer medium stream HTMS1, thereby obtaining a heat transfer medium stream HTMS2 having increased thermal energy compared to HTMS1, and a cooling medium stream CMS3 having decreased thermal energy compared to CMS2, which is at least partially recycled back to step 1a) as CMS1. Includes.

[0110] Step 1a) - Transfer of thermal energy via heat exchanger HE-C The transfer of thermal energy from the heat stream HS1 to the cooling medium stream CMS1 in step 1a) is preferably influenced by the heat exchanger HE-C.

[0111] The heat exchanger HE-C is preferably, - Pressure p when entering the entrance HS1 and temperature T HS1 An inlet for the heat stream HS1 having, - Pressure p when exiting the outlet HS2 and temperature T HS2 An outlet for the heat stream HS2 having, - Pressure p when entering the entrance CMS1 and temperature T CMS1 The inlet for the cooling medium stream CMS1, - Pressure p when exiting the outlet CMS2 and temperature T CMS2 Outlet for cooling medium stream CMS2 having It is equipped with.

[0112] HE-C=gas-liquid heat exchanger In a preferred embodiment, when the heat stream HS1 is a gaseous stream such as FS1, the heat exchanger HE-C is an indirect gas-liquid heat exchanger in which heat is transferred from the gaseous stream HS1 to the liquid cooling medium stream CMS1. Preferably, the gas-liquid heat exchanger is an expanded heat transfer surface heat exchanger, as described in Chapter 2.1.3 of the article "Heat Exchangers, 1. Fundamentals and General Design Methodology" in Ullmann's Encyclopedia of Industrial Chemistry (https: / / doi.org / 10.1002 / 14356007.b03_02.pub2), more preferably a plate-fin heat exchanger, as described in Chapter 2.1.3.1 of the same document, or a finned-tube heat exchanger, as described in Chapter 2.1.3.2 of the same document.

[0113] The heat exchanger HE-C is preferably designed to satisfy the following requirements: - Temperature T CMS1 is, T FS1 Preferably 1 to 100K, more preferably 2 to 80K, and most preferably 5 to 50K lower than that. - Temperature T HS2 The temperature is preferably in the range of 20 to 80°C, more preferably in the range of 25 to 70°C, and most preferably in the range of 30 to 60°C.

[0114] Typically, pressure drops occur in indirect gas-liquid heat exchangers. To transport a gaseous heat stream HS2, such as FS2, from the heat exchanger HE-C to the absorption tower and overcome the pressure drop in the indirect heat exchanger HE-C, an additional blower or fan is recommended behind the outlet of the gaseous heat stream HS2.

[0115] HE-C=Direct heat exchanger In a more preferred embodiment, when the heat stream HS1 is a gaseous stream, and particularly when the heat stream HS1 is a fluid stream FS1, the heat exchanger HE-C is preferably a direct heat exchanger in which the heat stream HS1 is in direct contact with the cooling medium stream CMS1. Direct contact means that the streams are in direct physical contact with each other (direct heat exchange) rather than being separated by a division.

[0116] Direct heat exchange has the advantage of increasing the exchange area between the two fluid streams HS1 and CMS1, thereby reducing thermal resistance and maximizing thermal efficiency. In addition, direct heat exchangers generally have lower operating and capital costs than indirect heat exchangers due to their high heat transfer rate per unit volume and because contamination and corrosion are not usually a problem. Corrosion is caused by residual sulfur oxides (SO4). x When a metal is in the fluid stream FS1, if the temperature of any metal in contact with the fluid stream FS1 falls below the dew point of sulfuric acid (typically in the range of 110 to 170°C), dew point corrosion can occur, which is a significant problem in indirect heat exchangers. Furthermore, the pressure loss in a direct heat exchanger HE-C is smaller compared to an indirect gas-liquid heat exchanger. Therefore, the size of expensive equipment such as fans or blowers required to compensate for the pressure loss and transport the fluid stream FS2 to the absorption tower can be reduced, or even avoided.

[0117] Direct contact preferably occurs in a direct-contact cooler (DCC) where heat is transferred from a fluid stream FS1 to a liquid cooling medium stream CMS1. In this invention, the terms "direct-contact condenser" and "direct-contact cooler" are used synonymously because the degree of condensation that occurs in the DCC depends on the moisture content of the supply gas.

[0118] Direct contact cooling can be achieved with the following devices: a) spray columns, b) baffled tray columns, c) sieve tray or bubble tray columns, d) packed columns, e) pipeline contactors, and f) mechanically agitated contactors.

[0119] Further details related to the design of direct-contact condensers are described in the review by Madejski et al. (Madejski, P.; Kus, T.; Michalak, P.; Karch, M.; Subramanian, N. Direct Contact Condensers: A Comprehensive Review of Experimental and Numerical Investigations on Direct-Contact Condensation. Energies 2022, 15, 9312. https: / / doi.org / 10.3390 / en15249312) and Kreith, Frank & Boehm, Robert. (1987). Direct-Contact Heat Transfer. 10.1615 / AtoZ.d.DIRCONHEATRA, Chapter 19, pages 1359 to 1399.

[0120] Typically, direct contact coolers operate in counterflow mode, meaning the heat stream HS1 enters an inlet that is typically on the opposite side of the inlet for the cooling medium stream CMS1. However, it is also possible to operate a DCC in parallel flow mode, where CMS1 and HS1 enter the heat exchanger from the same direction. Parallel flow mode DCCs are described in U.S. Patent No. 9034081.

[0121] The most preferred direct-contact coolers are spray columns, baffle tray columns, sieve tray or bubble tray columns, and packed columns. More preferably, the cooler operates in counter-flow mode.

[0122] In DCC, the heat stream HS1 is in direct contact with the cooling medium stream CMS1, and thermal energy is transferred from the heat stream HS1 to obtain a cooled heat stream HS2 and a heated cooling medium stream CMS2.

[0123] The cooling medium stream CMS1 is preferably ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, and their corresponding polyglycols (e.g., diethylene glycol, triethylene glycol, 1,2-dipropylene glycol, 1,2-tripropylene glycol, 1,3-dipropylene glycol, and 1,3-tripropylene glycol), their corresponding methyl or dimethyl ether, water, or mixtures thereof. Preferably, the cooling medium stream is ethylene glycol or water, or a mixture of ethylene glycol and water. Most preferably, the cooling medium stream consists essentially of water. The use of pure water has the advantage of not requiring an additional separation step. An additional separation step is preferable if the cooling medium stream CMS1 contains other components besides water. This is because the water in the heat stream HS1 results in a dilution of the concentration of other non-aqueous components. An additional separation step is required to separate the water introduced in the heat stream HS1 in order to return to the original concentration.

[0124] Direct-contact coolers are preferably designed to satisfy the following requirements: - Temperature T CMS1 The temperature is in the range of 25 to 100°C, preferably 25 to 70°C, and more preferably 30 to 50°C. - Temperature T CMS2 is, T CMS1 It is approximately 5-100K higher, preferably 10-80K, and more preferably 15-50K higher. - Temperature T HS2 The temperature is preferably in the range of 20 to 80°C, more preferably in the range of 25 to 70°C, and most preferably in the range of 30 to 60°C.

[0125] DCC is also typically operated in such a way that the cooling medium stream CMS2 remains in a liquid state and can therefore be easily separated from the gaseous fluid stream FS2.

[0126] If additional moisture in the heat stream HS1 condenses in the DCC, especially when HS1 is the fluid stream FS1, a portion of the cooling medium stream CMS2 may be purged from the cooling medium stream cycle. The amount of cooling medium stream to be purged is selected so that the flow rate of the cooling medium remains essentially constant.

[0127] In a preferred embodiment, the heat exchanger HE-C is designed to move more energy than is required to supply to the regeneration step. In this case, the excess energy can preferably be used to supply excess steam, which can then be moved to the field steam network and distributed to other field processes or process steps that may require such energy.

[0128] Alternatively, the heat exchanger HE-C can be designed so that less energy is transferred than is required in the regeneration step. In this case, it is preferable to provide additional energy, preferably steam, to the regeneration step from another source, for example, an on-site steam network that distributes steam from another steam source.

[0129] If the heat stream HS1 is a fluid stream FS1, the heat exchanger HE-C is preferably designed such that the transferred thermal energy is just enough to provide the thermal energy required in regeneration step c). If the heat stream FS1 contains more thermal energy or heat than is required to be transported by the heat pump to regeneration step c), only the energy required in regeneration step c) is transferred to the heat exchanger HE-C. If, after the transfer of the heat or thermal energy required for regeneration step c), the fluid stream FS2 is too hot to enter the absorption tower, the fluid stream FS2 leaving the heat exchanger HE-C is cooled in one or more additional heat exchangers before entering the absorption tower, so that the fluid stream FS2 has a temperature in the range of 20-80°C, more preferably 25-70°C, and most preferably 30-60°C at the inlet of the absorption tower. Such additional heat exchangers are water coolers such as air coolers or cooling towers. An overview of cooling towers that can be used to further cool the fluid stream FS2 is described in the Wikipedia article "Cooling Towers" (https: / / en.wikipedia.org / wiki / Cooling_tower#). This embodiment has the advantage that the temperature of the fluid stream FS2 at the absorption tower inlet can be adjusted independently of the operation of the heat pump HP1.

[0130] Step 1b) Transfer of thermal energy from the cooling medium stream CMS2 to the heat pump HP1 After thermal energy is transferred from heat stream HS1 to cooling medium stream CMS1, and a cooling medium stream CMS2 having higher thermal energy compared to cooling medium stream CMS1 is obtained, step 1b) is preferably performed by transferring at least a portion of the thermal energy contained in cooling medium CMS2 to heat transfer medium stream HTMS1 of heat pump HP1, thereby obtaining heat transfer medium stream HTMS2 having increased thermal energy compared to HTMS1, and cooling medium stream CMS3 having decreased thermal energy compared to CMS2 and being at least partially recycled back to step 1a) as CMS1.

[0131] In step 1b), CMS2 functions as a heat source for the heat pump HP1, and thermal energy is transferred from the cooling medium stream CMS2 to the heat transfer medium stream HTMS1. The transfer of thermal energy in step 1b) is influenced by a heat exchanger HE1, which is preferably an indirect heat exchanger.

[0132] In the case of indirect heat transfer via an intermediate cooling cycle, the heat exchanger HE-1 is preferably, - Pressure p when entering the entrance CMS2 and temperature T CMS2 An inlet for the cooling medium stream CMS2 having, - Pressure p when exiting the outlet CMS3 and temperature T CMS3 An outlet for the cooling medium stream CMS3 having, - Pressure p when entering the entrance HTMS1 and temperature T HTMS1 The inlet for the heat transfer material stream HTMS1, - Pressure p when exiting the outlet HTMS2 and temperature T HTMS2 Outlet for heat transfer medium stream HTMS2 having It is equipped with.

[0133] In the case of indirect heat transfer via an intermediate cooling cycle, the heat exchanger HE1 is preferably an indirect heat exchanger such as an evaporator, and in particular, HE1 is preferably a tubular heat exchanger, preferably a shell tube heat exchanger, a double-pipe heat exchanger, and a drip-type heat exchanger, or a plate heat exchanger. Most preferably, the heat exchanger HE1 is a shell tube heat exchanger or a plate heat exchanger.

[0134] In the case of indirect heat transfer via an intercooling cycle, the heat exchanger HE1 is preferably designed to satisfy the following requirements: - Temperature T CMS2 The temperature range is 25 to 120°C, preferably 30 to 100°C, and more preferably 40 to 70°C. - Temperature T HTMS2 is, T HTMS1 This is approximately 0.1 to 50K higher, preferably 0.5 to 25K, and more preferably 1 to 10K higher. - The heat transfer material HTM1 in the heat transfer material stream HTMS1 undergoes at least a partial phase transition from liquid to gaseous state.

[0135] The cooling medium stream CMS3 may need to undergo an additional cooling step 1c), which is preferably performed in a heat exchanger HE-CMS, which is a water cooler or air cooler, in order to recycle the cooling medium stream CMS3 as the cooling medium stream CMS1, with the effect of imparting the same characteristics to the cooling medium stream CMS3 as to the cooling medium stream CMS1.

[0136] In both direct transfer via step 1) and indirect heat transfer via the intermediate cooling cycle in steps 1a) and 1b), thermal energy is transferred to the heat transfer material stream HTMS1 to obtain a heat transfer stream HTMS2 having increased thermal energy compared to the heat transfer medium stream HTMS1.

[0137] Therefore, the heat transfer material HTM1 is preferably selected from the materials listed above so that a phase transition can occur at the temperature and pressure observed in the heat exchanger HE1.

[0138] Step 2) Compressing HTMS2 to HTMS3 After transferring thermal energy to the heat transfer medium stream HTMS2, the thermal energy is further transferred, preferably in step 2), by compressing the heat transfer medium stream HTMS2 in the first heat pump HP1 to obtain a heat transfer medium stream HTMS3 having a higher pressure than the heat transfer medium stream HTMS2.

[0139] Compression is preferably affected in the compressor.

[0140] A compressor is a device used to increase the pressure of a fluid that is at least partially gaseous.

[0141] Compressors are typically positive displacement compressors or dynamic compressors. Positive displacement compressors include reciprocating compressors that use a piston driven by a crankshaft to deliver fluid at a higher pressure. Reciprocating compressors can be single-stage or multi-stage. Positive displacement compressors also include rotary screw compressors, conical screw compressors, rotary vane compressors, rolling piston compressors, or scroll compressors.

[0142] The compressor can also be a dynamic compressor, such as a centrifugal compressor or an axial flow compressor.

[0143] Preferably, the compressor is a rotary screw compressor, a centrifugal compressor, a piston compressor, or an axial flow compressor.

[0144] Compression can be performed using one compressor or a series of compressors, depending on the desired pressure increase of the heat transfer material HTM1.

[0145] The heat transfer material HTM1 is under pressure p HTMS2 and temperature T HTSM2 The heat transfer material stream enters the compression step as HTMS2, and pressure p HTMS3 and temperature T HTMS3 The heat transfer material HTMS3 exits the compression step.

[0146] Pressure rise Δp(p HTMS3 -p HTMS2 Typically, the temperature of the heat transfer medium stream is selected to rise to a temperature at which a liquid-to-gas phase transition can be induced in the heat transfer material HTM2 of the second heat pump HP2. Preferably, the pressure is set such that the HTMS3 is p SHTMS1 The pressure in the heat pump HP2 is raised to be 50K or more, more preferably 80K or more, and most preferably 100K or more, above the boiling point of the heat transfer material HTM2.

[0147] Step 3) Heat transfer from HP1 to HP2 After increasing the pressure to obtain the heat transfer material stream HTMS3, in step 3), thermal energy is transferred from the heat transfer medium stream HTMS3 of the first heat pump HP1 to the second heat transfer medium stream SHTMS1 of the second heat pump HP2, thereby obtaining the second heat transfer medium stream SHTMS2 having increased thermal energy compared to the second heat transfer medium stream SHTMS1, and the heat transfer medium stream HTMS4 having a decreased thermal energy content compared to the heat transfer medium stream HTMS3, thus further transferring thermal energy from the heat pump HP1 to the heat pump HP2.

[0148] Heat pump HP2 The transfer of heat from the heat transfer material stream HTMS3 to the second heat transfer material stream HTMS1 is preferably influenced by the heat exchanger HE2.

[0149] The heat exchanger HE2 is a device used to transfer thermal energy in the form of heat between a heat transfer material stream HTMS3 and a second heat transfer medium stream SHTMS1 to obtain a second heat transfer medium stream SHTMS2 having increased thermal energy compared to the heat transfer medium SHTMS1, and a heat transfer material stream HTMS4 having decreased thermal energy compared to the heat transfer material stream HTMS3.

[0150] The heat exchanger HE2 is preferably an indirect heat exchanger.

[0151] If the heat exchanger HE2 is an indirect heat exchanger, HE2 is preferably, - Pressure p when entering the entrance HTMS3 and temperature T HTMS3 An inlet for the heat transfer medium stream HTMS3 having, - Pressure p when exiting the outlet HTMS3 and temperature T HTMS3 An outlet for the heat transfer medium stream HTMS3 having, - Pressure p when entering the entrance SHTMS1 and temperature T SHTMS1 An inlet for a second heat transfer medium stream SHTMS1 having, - Pressure p when exiting the outlet SHTMS2 and temperature T SHTMS2 An outlet for the second heat transfer medium stream SHTMS2 having It is equipped with.

[0152] More preferably, the heat exchanger HE2 is a shell-and-tube exchanger or a plate exchanger.

[0153] The heat exchanger HE2 is preferably designed to satisfy the following requirements: - Temperature T HTMS3 The boiling point of the heat transfer material HTM2 in the regulated pressure heat pump HP2 is substantially higher than the boiling point of the pressure p SHTMS1 The boiling point of the heat transfer material SHTM1 is preferably 5 to 200 K or higher, preferably 5 to 50 K or higher, and most preferably 5 to 25 K or higher. - Temperature TS HTMS2 is, T SHTMS1 This is approximately 0.1 to 50 K higher, preferably 0.3 to 15 K, and more preferably 1 to 5 K higher. - The heat transfer material HTM2 in the heat pump HP2 within the second heat transfer material stream SHTMS1 undergoes at least a partial phase transition from liquid to gaseous state. - pressure p SHTMS1 The pressure p is preferably in the range of about 1 bar. SHTMS1 The pressure p on the second heat transfer material SHTM side can be less than atmospheric pressure, such as 0.1 to 1 bar, but in a preferred embodiment, the pressure p on the second heat transfer material SHTM side is... SHTMS1 The pressure is above atmospheric pressure, preferably in the range of 0.7 to 2 bar, more preferably 0.8 to 1.5 bar, and more preferably 0.9 to 1.2 bar.

[0154] Heat transfer material HTM2 The heat transfer material HTM2 is the working fluid used in the heat pump HP2 to transport thermal energy from heat exchanger HE2 to heat exchanger HE-R.

[0155] Preferably, the heat transfer material HTM2 can undergo at least a partial phase transition from liquid to gaseous state during the transfer of thermal energy in the heat exchanger HE2.

[0156] Preferably, the heat transfer material HTM2 may also undergo at least a partial phase transition from gas to liquid state during the transfer of thermal energy in the heat exchanger HE-R.

[0157] The heat transfer material HTM2 is preferably p SHTMS1 The boiling point at p HTMS3 T in HTMS3 It is a substance that is lower than and also lower than the temperature at which the regeneration tower operates.

[0158] Therefore, in addition to water, pressure p SHTMS1 Any other material having a boiling point of less than 150°C, preferably less than 140°C, and more preferably less than 130°C is preferred.

[0159] The most preferred heat transfer material HTM2 is water, because water can undergo a phase transition to steam, at least partially, in the heat exchanger HE2.

[0160] The second heat transfer material streams SHTMS1-5 are streams of heat transfer material 2 at different stages of the heat pump HP2. - The second heat transfer material stream SHTMS1 is the stream of heat transfer material HTM2 that enters step 3), - The second heat transfer material stream SHTMS2 is the stream of heat transfer material HTM2 that exits step 3) and enters step 4) for compression. - The second heat transfer material stream SHTMS3 is the stream of heat transfer material HTM2 that exits compression step 4) and enters step 5). - The second heat transfer material stream SHTMS4 is a stream of heat transfer material HTM2 that can exit step 5) and optionally enter the recycling step R2). - The second heat transfer material stream SHTMS5 is a stream of heat transfer material HTM2 that exits recycling step R2) and can be recycled to step 3) as the second heat transfer material stream SHTMS1.

[0161] Step 4) Compressing SHTMS2 to SHTMS3 In a preferred embodiment, the transfer of heat from heat pump HP1 to heat pump HP2, specifically to the second heat transfer material stream SHTMS2, is preferably followed by a compression step 4) in which the second heat transfer medium stream SHTMS2 in the second heat pump HP2 is compressed to obtain a second heat transfer medium stream SHTMS3 having a higher pressure than the second heat transfer medium stream SHTMS2.

[0162] Compression is preferably affected in the compressor.

[0163] A compressor is a device used to increase the pressure of a fluid that is at least partially gaseous.

[0164] Compressors are typically positive displacement compressors or dynamic compressors. Positive displacement compressors include reciprocating compressors that use a piston driven by a crankshaft to deliver fluid at a higher pressure. Reciprocating compressors can be single-stage or multi-stage. Positive displacement compressors also include rotary screw compressors, conical screw compressors, rotary vane compressors, rolling piston compressors, or scroll compressors.

[0165] The compressor can also be a dynamic compressor, such as a centrifugal compressor or an axial flow compressor.

[0166] Preferably, the compressor is a rotary screw compressor, a centrifugal compressor, a piston compressor, or an axial flow compressor.

[0167] Compression can be performed using one compressor or a series of compressors, depending on the desired pressure increase of the heat transfer material HTM2.

[0168] The heat transfer material HTM2 is under pressure p SHTMS2 and temperature T SHTSM2 The heat transfer material stream SHTMS2 enters the compression step, and pressure p SHTMS3 and temperature T SHTMS3 The heat transfer material SHTMS3 exits the compression step as a stream.

[0169] Pressure rise Δp(p SHTMS3 -p SHTMS2 The pressure is typically 1 to 20 bar, preferably 1.2 to 10 bar, more preferably 1.5 to 3 bar, and the accompanying temperature rise is preferably 20 to 2000 K, more preferably 25 to 6 K, most preferably 30 to 50 K.

[0170] In a preferred embodiment, the compression step is performed in a series of two or more compressors, and the heat transfer material HTM2 is water. In this embodiment, an additional stream of heat transfer material HTM2 is supplied after each of the series compressors to increase the amount of gaseous heat transfer material HTM2 generated at the expense of lowering the temperature of the stream. In this way, it is possible to generate enough steam for regeneration step c). In addition, the addition of further heat transfer material HTM2 is energetically advantageous in a scenario in which the same amount of gaseous heat transfer material HTM2 is generated compared to a scenario in which the additional heat transfer material HTM2 is not introduced after the compression step. Preferably, saturated steam is generated and used for heating in the reboiler HE-R. Injecting water between the compressor sections helps to reduce steam overheating.

[0171] In addition, the injection of the additional heat transfer material HTM2 results in a reduction in volumetric flow rate and a reduction in the power requirements of subsequent compressors during the successive compression phases.

[0172] Step 5) Transfer of thermal energy from SHTSM3 to regeneration step c) According to a preferred embodiment of the present invention, in step 5), thermal energy is transferred to regeneration step c) by transferring thermal energy from the second heat transfer medium stream SHTMS3 of the second heat pump HP2 to regeneration step c) to obtain a second heat transfer medium stream SHTMS4 having a reduced thermal energy content compared to SHTMS3.

[0173] The transfer of thermal energy from the second heat transfer material stream SHTMS3 to regeneration step c) can occur indirectly or directly, as will be further explained below.

[0174] Indirect heat transfer to regeneration step c) In a preferred embodiment of the present invention, the transfer of thermal energy from the second heat transfer material stream HTMS3 to regeneration step c) takes place in a heat exchanger HE-R, where the absorbed absorbent A2 obtained in step b) is heated before entering regeneration step c).

[0175] Before entering regeneration step c), the heat exchanger HE-R may be replaced by or added to a direct-to-alternating-voltage heat exchanger used to transfer heat from the regenerated absorbent A3 to the absorbed absorbent A2.

[0176] The heat exchanger HE-R is preferably an indirect heat exchanger.

[0177] If the heat exchanger HE-R is an indirect heat exchanger, HE-R is preferably, - Inlet for absorbent A2, - The outlet for absorbed absorbent A2 has increased thermal energy compared to the absorbed absorbent A2 at the inlet of the heat exchanger HE-R, - Pressure p when entering the entrance SHTMS1 and temperature T SHTMS1 An inlet for a second heat transfer medium stream SHTMS1 having, - Pressure p when exiting the outlet SHTMS2 and temperature TS HTMS2 An outlet for the second heat transfer medium stream SHTMS2 having It is equipped with.

[0178] More preferably, the heat exchanger HE-R is a shell-and-tube exchanger or a plate exchanger.

[0179] This embodiment may be particularly useful in the case of exhaust gas when an intermediate evaporation or flushing step is performed after a direct-to-intermediate heat exchanger HE-CF. In this case, the absorbent stream A2, which has been at least partially taken up, can be reheated before entering the regeneration tower.

[0180] Direct heat transfer to regeneration step c) In the most preferred embodiment, thermal energy is transferred directly from the second heat transfer medium stream SHTMS3 to the bottom of the regeneration tower in regeneration step c).

[0181] More preferably, the transfer of thermal energy is influenced via a heat exchanger HE-R connected to the bottom of the regenerative tower where heat exchange proceeds indirectly. Most preferably, the indirect heat exchanger HE-R is a reboiler.

[0182] A reboiler typically comprises an inlet connected to the bottom of the regeneration column, through which the absorbent stream AS1 enters the reboiler, and an outlet connected to an inlet at the bottom of the regeneration column, through which the absorbent stream AS2 exits the reboiler and re-enters the regeneration column.

[0183] The reboiler also includes an inlet into which a second heat transfer material stream SHTMS3 enters and an outlet into which the second heat transfer material stream SHTMS4 exits the reboiler.

[0184] The HE-R is preferably a reboiler selected from the group consisting of a kettle-type reboiler, a thermosiphon-type reboiler, and a forced-circulation reboiler.

[0185] Upon heating of the absorbent stream AS2, acidic gases, particularly CO2, are typically desorbed, and the water contained in the absorbent is vaporized into the stream, at least partially, exerting a dissipation effect and leading to further release of acidic gases from the absorbent that has already absorbed the gases.

[0186] Further details relating to regeneration step c) and recycling step d) will be described in later sections of this specification.

[0187] Recycling Step R1 In a preferred embodiment, the method of the present invention includes an additional recycling step R1) in which the heat transfer material stream HTMS4 obtained in step 3) is expanded to obtain a heat transfer medium stream HTMS5 having a reduced pressure compared to the heat transfer material stream HTMS4, which is at least partially recycled back to step 1) as the heat transfer material stream HTMS1.

[0188] Expansion is preferably caused by the pressure p of the heat transfer medium stream HTMS4. HTMS4 The pressure p of the heat transfer medium stream HTMS5 HTMS5 It is affected by being reduced to [a certain level].

[0189] Expansion is preferably influenced by a thermal expansion valve. Thermal expansion valves that can be used in recycling step R1) are described in the Wikipedia article "Thermal Expansion Valve" (https: / / en.wikipedia.org / wiki / Thermal_expansion_valve). HTMS4 from p HTMS5 A pressure drop Δp typically results in adiabatic flash evaporation of a portion of the heat transfer medium stream (HTMS4), and the self-cooling effect of this adiabatic flash evaporation lowers the temperature of the heat transfer medium stream (HTMS4).

[0190] The expansion valve is preferably configured such that the heat transfer material stream HTMS5 can be recycled to step 1 as the heat transfer material stream HTMS1. HTMS5 ga p HTMS1 Equivalent to, T HTMS5 is T HTMS1 It operates and is designed to be equivalent to [this].

[0191] Recycling Step R2 In a further preferred embodiment, the method of the present invention includes an additional recycling step R2) of expanding the second heat transfer material stream SHTMS4 obtained in step 5) to obtain a second heat transfer medium stream SHTMS5 having a reduced pressure compared to the second heat transfer material stream SHTMS4 and being at least partially recycled to step 3) as the second heat transfer material stream SHTMS1.

[0192] The expansion preferably affects the pressure pS of the heat transfer medium stream SHTMS4 HTMS4 to reduce it to the pressure p SHTMS1 of the heat transfer medium stream SHTMS1.

[0193] The expansion preferably is affected by a thermal expansion valve. The thermal expansion valve that can be used in step 4) is described in the Wikipedia article "Thermal Expansion Valve" (https: / / en.wikipedia.org / wiki / Thermal_expansion_valve).

[0194] p SHTMS4 to p SHTMS5 The pressure drop Δp causes partial adiabatic flash evaporation of the heat transfer medium stream SHTMS4, and the self-cooling effect of the adiabatic flash evaporation reduces the temperature of the heat transfer medium stream SHTMS4.

[0195] The expansion valve preferably operates and is designed such that p SHTMS5 is equal to p SHTMS1 and T SHTMS5 is equal to T SHTMS1 .

[0196] The heat transfer medium stream SHTMS5 is preferably recycled as the heat transfer material stream SHTMS1 to step 1) of the evaporation process.

[0197] Performing at least one of the additional recycling steps R1 and R2 has the advantage of allowing the heat transfer materials HTM1 and HTM2 to be reused in a closed-cycle heat pump in order to save material costs or to prevent environmental pollution associated with the loss of heat transfer materials HTM1 or HTM2 if environmentally harmful heat transfer materials HTM1 or HTM2 are selected.

[0198] If the heat transfer material HTM2 is water / steam, it is not essential to expand the second heat transfer material stream SHTM4 to recycle the water, as the water may be discarded into the environment or used to transfer heat to other processes. In this case, it is preferable not to directly recycle the second heat transfer material stream SHTMS4 into the heat exchanger HE-1.

[0199] However, the method of the present invention may preferably include a recycling step R2 in order to conserve resources, particularly when the availability of the heat transfer material HTM2 is limited in the production site, and when the heat transfer material HTM2 is water or another heat transfer material HTM2.

[0200] The present invention may also comprise two or more heat pumps connected in series, such as three or four heat pumps, where the condenser of one heat pump is the evaporator of a subsequent heat pump. The last heat pump in a series of two or more heat pumps performs the function of heat pump HP2 in the series of two heat pumps. The heat transfer material of the last heat pump in series is preferably water for the same reason, and water is the preferred heat transfer material HTM2 in heat pump HP2.

[0201] Acid gas absorption process - Absorption step b) According to the present invention, the fluid stream FS2 is deoxidized in absorption step b) in which the cooled fluid stream FS2 is brought into contact with absorbent A1 in an absorption tower to obtain absorbent A2 that has absorbed acidic gas and a fluid stream that is at least partially deoxidized.

[0202] Absorbent: The absorbent contains at least one amine.

[0203] The following amines are preferred. i) An amine of formula (I): NR 1 (R 2 )2(I) In the formula, R 1 is selected from a C2-C6-hydroxyalkyl group, a C1-C6-alkoxy-C2-C6-alkyl group, a hydroxy-C1-C6-alkoxy-C2-C6-alkyl group, and a 1-piperazinyl-C2-C6-alkyl group, and R 2 is independently selected from H, a C1-C6-alkyl group, and a C2-C6-hydroxyalkyl group. ii) An amine of formula (II): R 3 R 4 N-X-NR 5 R 6 (II) In the formula, R 3 , R 4 , R 5 , and R 6 are independently selected from H, a C1-C6-alkyl group, a C2-C6-hydroxyalkyl group, a C1-C6-alkoxy-C2-C6-alkyl group, and a C2-C6-aminoalkyl group, X is a C2-C6-alkylene group, -X 1 -NR 7 -X 2 - or -X 1 -O-X 2 -, where in the formula, X 1 and X 2 are independently a C2-C6-alkylene group, and R 7 is H, a C1-C6-alkyl group, a C2-C6-hydroxyalkyl group, or a C2-C6-aminoalkyl group. iii) A 5- to 7-membered saturated heterocyclic ring having at least one nitrogen atom in the ring and optionally containing one or two additional heteroatoms selected from nitrogen and oxygen in the ring. iv) Mixtures thereof.

[0204] The following are specific examples of amines that can be used according to preference. i) 2-aminoethanol (monoethanolamine), 2-(methylamino)ethanol, 2-(ethylamino)ethanol, 2-(n-butylamino)ethanol, 2-amino-2-methylpropanol, N-(2-aminoethyl)piperazine, methyldiethanolamine, ethyldiethanolamine, dimethylaminopropanol, t-butylaminoethoxyethanol (TBAEE), 2-amino-2-methylpropanol, diisoproanolamine (DIPA). ii) 3-methylaminopropylamine, ethylenediamine, diethylenetriamine, triethylenetetraamine, 2,2-dimethyl-1,3-diaminopropane, hexamethylenediamine, 1,4-diaminobutane, 3,3-iminobispropylamine, tris(2-aminoethyl)amine, bis(3-dimethylaminopropyl)amine, tetramethylhexamethylenediamine. iii) Piperazine, 2-methylpiperazine, N-methylpiperazine, 1-hydroxyethylpiperazine, 1,4-bishydroxyethylpiperazine, 4-hydroxyethylpiperidine, homopiperazine, piperidine, 2-hydroxyethylpiperidine, triethylenediamine (TEDA), and morpholine. iv) A mixture of those.

[0205] In preferred embodiments, the absorbent comprises at least one of the following amines: monoethanolamine (MEA), methylaminopropylamine (MAPA), piperazine (PIP), diethanolamine (DEA), triethanolamine (TEA), diethylethanolamine (DEEA), diisopropanolamine (DIPA), aminoethoxyethanol (AEE), tert-butylaminoethoxyethanol (TBAEE), dimethylaminopropanol (DIMAP), and methyldiethanolamine (MDEA), triethylenediamine (TEDA), or a mixture thereof.

[0206] Further amines that can be introduced into this process are tert-butylaminopropanediol, tert-butylaminoethoxyethylmorpholine, tert-butylaminoethylmorpholine, methoxyethoxyethoxyethyl-tert-butylamine, and tert-butylaminoethylpyrrolidone.

[0207] The amine is preferably a sterically hindered amine or a tertiary amine. A sterically hindered amine is a secondary amine in which the amine nitrogen is bonded to at least one secondary carbon atom and / or at least one tertiary carbon atom, or a primary amine in which the amine nitrogen is bonded to a tertiary carbon atom. A preferred sterically hindered amine is t-butylaminoethoxyethanol. Preferred tertiary amines are methyldiethanolamine and triethylenediamine (TEDA).

[0208] If the objective is to completely or substantially completely remove CO2 present in a fluid stream, and the amine present in the absorbent is a sterically hindered amine or a tertiary amine, the absorbent preferably additionally includes an activator. The activator is generally a sterically unhindered primary or secondary amine. In these sterically unhindered amines, at least one amine nitrogen of the amino group is bonded only to primary carbon and hydrogen atoms. If the objective is simply to remove a portion of the gas present in a fluid stream, for example, selectively removing H2S from a fluid stream containing H2S and CO2, the absorbent preferably does not include any activator.

[0209] Examples of sterically unhindered primary or secondary amines that can be used as activators include alkanolamines (monoethanolamine (MEA), diethanolamine (DEA), ethylaminoethanol, 1-amino-2-methylpropane-2-ol, 2-amino-1-butanol, 2-(2-aminoethoxy)ethanol, and 2-(2-aminoethoxy)ethaneamine, etc.), polyamines (hexamethylenediamine, 1,4-diaminobutane, 1,3-diaminopropane, 3-(methylamino)propylamine (MAPA), N-(2-hydroxyethyl)ethylenediamine) Selected from 3-(dimethylamino)propylamine (DMAPA), 3-(diethylamino)propylamine, N,N'-bis(2-hydroxyethyl)ethylenediamine, etc., and 5-membered, 6-membered, or 7-membered saturated heterocycles (such as piperazine, 2-methylpiperazine, N-methylpiperazine, N-ethylpiperazine, N-(2-hydroxyethyl)piperazine, N-(2-aminoethyl)piperazine, homopiperazine, piperidine, and morpholine) having at least one NH group in the ring and potentially containing one or two further heteroatoms selected from nitrogen and oxygen in the ring.

[0210] Particularly preferred are five-membered, six-membered, or seven-membered saturated heterocycles having at least one NH group in the ring and potentially containing one or two further heteroatoms selected from nitrogen and oxygen. Piperazines are especially preferred.

[0211] The molar ratio of the activator to the sterically hindered amine or tertiary amine is preferably in the range of 0.05 to 1.0, more preferably in the range of 0.05 to 0.7.

[0212] Absorbents generally contain 10% to 60% by weight of amines.

[0213] In one embodiment, the absorbent comprises methyldiethanolamine, which is a tertiary amine, and piperazine, which is an activator.

[0214] In a preferred embodiment, the absorbent is A) At least one cyclic amine compound having only a tertiary amine group, and B) at least one cyclic amine compound having at least one unhindered secondary amine group and the total concentration of A) + B) is 10 to 60% by weight.

[0215] Such an absorbent is disclosed in European Patent No. 2391435. Most preferably, amine A) is triethylenediamine (TEDA) and activator amine B) is piperazine.

[0216] The absorbent may additionally contain a physical solvent. Suitable physical solvents are, for example, N-methylpyrrolidone, tetramethylene sulfone, oligoethylene glycol dialkyl ethers (such as oligoethylene glycol methyl isopropyl ether (SEPASOLV MPE), oligoethylene glycol dimethyl ether (SELEXOL), etc.). The physical solvent is generally present in the absorbent in an amount of 1% to 60% by weight, preferably 10% to 50% by weight, particularly 20% to 40% by weight.

[0217] In a preferred embodiment, the absorbent contains an inorganic basic salt (such as potassium carbonate, etc.) of less than 10% by weight (for example, less than 5% by weight, particularly less than 2% by weight).

[0218] The absorbent may also contain additives such as corrosion inhibitors, antioxidants, enzymes, antifoaming agents, etc. Generally, the amount of such additives is in the range of about 0.01 to 3% by weight of the absorbent.

[0219] Unused absorbent can be supplied to the absorption column, or regenerated absorbent in the recycling step c) can be supplied to the absorption column. The supply of unused absorbent means that the components of the absorbent have not yet passed through steps b) to d). For the supply of regenerated absorbent, it is necessary that at least a part of the components of the absorbent have passed through steps b) to d).

[0220] The absorbent is preferably aqueous. This means that a wide variety of different components of the absorbent, such as amines, methanol, physical solvents, and additives, can be mixed with water in the amounts mentioned above.

[0221] Absorption tower: The fluid stream FS2 is preferably brought into contact with the absorbent in the absorption tower in step b).

[0222] The absorber is preferably an absorption tower or an absorption column, such as a column or tray column having irregular or regular packing.

[0223] An absorption tower generally comprises an absorption zone and, optionally, a rescrubbing zone.

[0224] The absorption zone is considered to be the section of the absorption column where the fluid stream makes mass transfer contact with the absorbent.

[0225] The fluid stream is preferably in contact with the absorbent in a countercurrent manner within the absorption zone.

[0226] To improve contact with the absorbent and provide a large mass transfer interface, the absorbent zone generally comprises internal structures, such as irregular packing, regular packing, and / or trays (valve trays, bubble cap trays, Thormann trays, or sieve trays, etc.).

[0227] If the absorption zone is equipped with irregular or regular packing, the height of the irregular / regular packing in the absorption zone is preferably in the range of 5 to 20 m, more preferably in the range of 6 to 15 m, and most preferably in the range of 8 to 14 m.

[0228] If the absorption zone includes trays, the number of trays in the absorption zone is preferably in the range of 8 to 30 trays, more preferably in the range of 12 to 25 trays, and most preferably in the range of 15 to 23 trays.

[0229] For columns with irregular or regular packing, the absorption zone may be divided into one or more sections, preferably two to four sections. Support trays and holding trays and / or distribution trays may be placed between the individual sections of the absorption zone, which improve the distribution of the absorbent across the entire cross-section of the column.

[0230] The temperature of the absorbent introduced into the absorption zone is generally 0 to 60°C, preferably 10 to 50°C, and more preferably 25 to 50°C.

[0231] The pressure inside the absorption tower depends on the pressure and type of the fluid stream FS2 entering the absorption tower.

[0232] When the fluid stream FS2 is synthesis gas, the pressure inside the absorption tower is typically in the range of 5 to 120 bar, more preferably 10 to 100 bar, and most preferably 10 to 60 bar.

[0233] When the fluid stream FS2 is exhaust gas, the pressure inside the absorption tower is typically in the range of preferably 0.7 to 1.5 bar, more preferably 0.8 to 1.3 bar, and more preferably 0.9 to 1.2 bar. Most preferably, when the fluid stream FS2 is exhaust gas, the absorption tower operates at atmospheric pressure.

[0234] The supply point for the introduced fluid stream is preferably located below the absorption zone or in the lower region of the absorption zone. The supply is preferably distributed uniformly across the cross-section of the absorption tower via a gas distributor.

[0235] The absorption tower may have one or more supply points for the absorbent introduced. For example, the absorption tower may have a supply point for the unused absorbent A1 and a supply point for the regenerated absorbent A3. Alternatively, the unused and regenerated absorbents may be supplied to the absorption tower together via one supply point. The one or more supply points are preferably above the absorption zone or in the upper region of the absorption zone. It is also possible to supply the individual components (such as makeup water) of the absorbent via the supply point for the unused absorbent.

[0236] If the absorption tower has an optional re-scrubbing zone, the supply port is preferably between the absorption tower zone and the re-scrubbing zone.

[0237] By contacting the fluid stream in the absorption zone with the absorbent, a fluid stream FS3 that is at least partially deacidified and an absorbent that has taken in the acid gas are obtained.

[0238] In the upper region of the absorption tower, there is generally a draw point for the deacidified fluid stream FS3. A demister may be installed in the region of the draw point to separate any liquid residue of the absorbent or scrubbing agent from the flowing fluid stream.

[0239] Generally, in the lower region of the absorption tower, preferably at the bottom of the tower, there is a draw point for the absorbent FS2 that has been taken in.

[0240] The fluid stream FS3 that is at least partially deacidified may optionally be contacted with a scrubbing liquid in one or more re-scrubbing zones (collectively referred to as "re-scrubbing zones").

[0241] The scrubbing liquid is more preferably an aqueous liquid. The scrubbing liquid may be a liquid specific to the process, i.e., an aqueous liquid obtained from other locations in the process, or an aqueous liquid supplied externally. Preferably, the scrubbing liquid contains condensate (referred to as the overhead condensate of the absorption tower) formed in a downstream cooling operation for the deacidified fluid stream and / or fresh water.

[0242] The rescrubbing zone is generally the section of the absorption tower located above the point where the absorbent is supplied.

[0243] The rescrubbing zone preferably has irregular packing, regular packing, and / or trays to enhance contact between the fluid stream and the scrubbing fluid. The rescrubbing zone particularly has trays, especially valve trays, bubble cap trays, Thormann trays, or sieve trays.

[0244] The rescrubbing zone preferably comprises 1 to 7 trays, more preferably 2 to 6 trays, most preferably 3 to 5 trays, or includes a packing height (irregular packing / regular packing) of preferably 1 to 6 m, more preferably 2 to 5 m, most preferably 2 to 3 m.

[0245] The scrubbing fluid is generally introduced above the rescrubbing zone, or into the upper region of the rescrubbing zone. The scrubbing fluid used may be one of the scrubbing fluids described above.

[0246] The scrubbing fluid can be recycled through a rescrubbing zone. This is achieved, for example, by collecting the scrubbing fluid below the rescrubbing zone using a suitable recovery tray and pumping it to the upper end of the rescrubbing zone. The recycled scrubbing fluid can be cooled to a temperature of preferably 20°C to 70°C, particularly 30°C to 60°C. This is advantageously achieved by recirculating the scrubbing fluid through a cooler. To avoid the accumulation of scrubbed-off absorbent components in the scrubbing fluid, a substream of the scrubbing fluid is preferably discharged from the rescrubbing zone.

[0247] Contact between the at least partially deoxidized fluid stream FS3 and the scrubbing fluid makes it possible to scrub away entrained absorbent components such as amines. Contact with an aqueous scrubbing fluid can also improve the water balance of the process if there is more water discharged through the outgoing stream than introduced through the ingoing stream.

[0248] The deoxidized fluid stream FS3 described above is preferably drawn out through a drawout point at the top of the absorption tower.

[0249] Optionally, the deoxidized fluid stream FS3 can be guided through a condenser.

[0250] The condensers used include, for example, condensers with cooling coils or helical tubes, flat plate heat exchangers, jacketed tube condensers, and shell-and-tube heat exchangers.

[0251] Condensers generally operate at temperatures in the range of 10 to 60°C, preferably 20 to 50°C, and more preferably 20 to 30°C.

[0252] The water content of a deoxidized fluid stream is generally 80-100% of the saturation concentration of water in the fluid stream under the applied temperature and pressure conditions.

[0253] Step b) yields absorbent A2 that has at least partially absorbed the acidic gas.

[0254] The absorbed absorbent A2 can be supplied directly to regeneration step c).

[0255] Inflation step (optional): In a particular embodiment of the process of the present invention, the expansion step is performed on the absorbed absorbent A2 first, before the absorbed absorbent A2 is introduced into the regeneration step c).

[0256] In the expansion step, the incorporated adsorbent A2 is generally guided into one or more expansion containers.

[0257] If the pressure inside the absorption tower is higher than the pressure inside the regeneration tower, the absorbent material that has already been absorbed can be expanded into the expansion vessel through a throttle valve.

[0258] If the fluid stream FS2 is synthesis gas, the incorporated adsorbent is preferably expanded to a pressure of 3 to 15 bar, preferably 4 to 12 bar, and more preferably 5 to 10 bar.

[0259] Expansion generally results in the desorption of so-called flash gas. The flash gas can be returned to the absorption by a compressor, incinerated for energy generation, or incinerated in place.

[0260] If the fluid stream FS2 is exhaust gas, the absorbed absorbent is preferably pumped to an expansion vessel located downstream of the direct-to-intermediate heat exchanger HE-CF. In this case, the pump can typically increase the pressure of the fluid stream FS2 to about 2-8 bar, thereby expanding the fluid stream FS2 to the expansion vessel, which is preferably operating at a pressure slightly higher than that of the regeneration tower. The effect of the expansion step is usually enhanced by the temperature increase of the fluid stream FS2 as it passes through the direct-to-intermediate heat exchanger HE-CF. Performing an additional expansion step has the advantage that at least some of the oxygen contained in the fluid stream FS2 may be flashed off, which negatively affects the required purity of the CO2.

[0261] A flash container is generally a container that does not contain any specific internal structure. A flash container is preferably a so-called flash drum. An alternative flash container is a column having an internal structure (e.g., irregular packing, regular packing, or tray).

[0262] In the upper region of the flash vessel, there is generally a gas outlet for the gas converted to the gas phase. A demister may preferably be positioned sequentially in the gas outlet region. If necessary, any acidic gases present may be separated from the flash gas in a further absorption column. Typically, for this purpose, a substream of regenerated solvent is fed into the additional absorption column.

[0263] At the bottom of the flash container, absorbent A2, which has at least partially absorbed the acidic gas that was not converted to the gas phase, is generally withdrawn and led to regeneration step c).

[0264] Playback step c): According to the present invention, an adsorbent A2 having at least partially absorbed an acidic gas is supplied to regeneration step C), in which at least a portion of the absorbed absorbent A2 obtained from step b) is regenerated in a regeneration tower to obtain a gaseous stream GS containing at least partially regenerated absorbent A3 and at least one acidic gas.

[0265] The gaseous stream GS may contain residual water that was not separated in the rescrubbing zone.

[0266] Before being introduced to regeneration step c), the adsorbent A2, which has at least partially absorbed the acidic gas, is preferably guided through a direct-to-alternating heat exchanger HE-CF.

[0267] In the direct-to-alternating heat exchanger HE-CF, the absorbent A2, which has at least partially absorbed the acidic gas, is preferably heated to a temperature in the range of 50 to 150°C, more preferably 70 to 130°C, and most preferably 80 to 110°C. In certain embodiments, the regenerated absorbent A3 drawn from the bottom of the regeneration column is used as a heating medium in the heat exchanger HE-CF. This embodiment has the advantage that the thermal energy of the regenerated absorbent A3 from step c) can be used to heat the absorbent A2 absorbed from step b) in the heat exchanger HE-CF. In this way, it is possible to further reduce the energy cost of the entire process and reduce the energy requirement in the reboiler in regeneration step c).

[0268] As described in more detail above, in a further preferred embodiment, the second heat transfer material stream SHTMS3 is used as a heating medium in the heat exchanger HE-R, either in addition to or as a replacement for the DC-AC heat exchanger HE-CF.

[0269] Play tower: According to the present invention, the regeneration step is performed in a regeneration tower.

[0270] Regeneration columns are generally configured as emission columns.

[0271] The regeneration tower preferably comprises a regeneration zone and a reboiler.

[0272] The regeneration tower is preferably operated with a tower top pressure in the range of 0.5 to 5 bar, preferably 0.7 to 4 bar, and more preferably 0.9 to 2.5 bar.

[0273] Generally, a liquid outlet for the recycled absorbent A3 is located at the bottom of the regeneration tower.

[0274] The top of the regeneration tower generally has a gas outlet for the gaseous stream GS. A demister is preferably mounted in the gas outlet area.

[0275] A regeneration tower generally has a regeneration zone located above the base of the tower and below the rescrubbing zone. In this context, the regeneration zone is considered to be the region of the regeneration tower where the absorbed absorbent comes into contact with the steam generated in the reboiler.

[0276] To improve contact and provide a large mass transfer interface, the regeneration zone generally comprises internal structures, such as irregular packing, regular packing, and / or trays (valve trays, bubble cap trays, Thormann trays, or sieve trays).

[0277] If the regeneration zone is equipped with regular or irregular packing, the height of the regular / irregular packing in the regeneration zone is preferably in the range of 5 to 15 m, more preferably in the range of 6 to 12 m, and most preferably in the range of 8 to 12 m.

[0278] If the regeneration zone includes trays, the number of trays in the regeneration zone is preferably in the range of 10 to 30 trays, more preferably in the range of 15 to 25 trays, and most preferably in the range of 17 to 23 trays.

[0279] In the case of columns with irregular or regular packing, the regeneration zone may similarly be divided into multiple sections, preferably 2 to 4 sections. Support trays and holding trays and / or distribution trays may be placed between the sections of the regeneration zone, which improve the distribution of liquid across the entire cross-section of the regeneration column.

[0280] Generally, the absorbed absorbent A2 is preferably introduced into the regeneration tower, either in the upper region of the regeneration zone, or above the regeneration zone and below the rescrubbing zone.

[0281] In the regeneration zone, the vapor generated in the evaporator generally acts countercurrently to the absorbent flowing downward through the regeneration zone.

[0282] In a regeneration tower, the zone below the regeneration zone is generally called the tower base.

[0283] In this region, the absorbent is typically recovered and (i) supplied to the reboiler HE-R as absorbent stream AS1 via a pipeline through a liquid outlet in the lower region of the regeneration tower, and / or (ii) partially recycled into the absorption tower as regenerated absorbent A3.

[0284] The bottom of the column can be divided by a recovery tray positioned between the bottom outlet and the supply point for the steam generated in the evaporator.

[0285] Generally, at least a portion of the regenerated absorbent A3 is guided into the reboiler from the bottom outlet of the regeneration column as absorbent stream AS1.

[0286] Preferably, the bottom drawout from the regenerating column is completely guided to the reboiler as an absorbent stream AS1.

[0287] Reboilers (HE-R) are typically kettle-type reboilers, natural circulation reboilers, thermal siphon reboilers, or forced circulation reboilers.

[0288] The reboiler HE-R of the regenerating tower is preferably located outside the regenerating tower and connected to the bottom outlet via a pipeline.

[0289] The reboiler HE-R is generally operated at temperatures in the range of 100-150°C, preferably 105-140°C, and more preferably 110-130°C.

[0290] In the reboiler HE-R, generally, at least a portion of the bottom drawout is evaporated and returned to the regeneration column as an absorbent stream AS2. The absorbent stream AS2 is preferably supplied to the bottom of the regeneration column, below the regeneration zone.

[0291] If an additional recovery tray is located at the bottom of the column, the steam generated in the reboiler is preferably supplied below the recovery tray.

[0292] Rescrubbing zone: In a preferred embodiment, the regeneration tower has a rescrubbing zone above the regeneration zone, and more preferably above the supply point for the absorbed absorbent A2.

[0293] The rescrubbing zone generally takes the form of a section of the regeneration tower located above the regeneration zone.

[0294] The rescrubbing zone preferably has internal structures, particularly irregular packing, regular packing, and / or trays, to enhance contact between the fluid stream and the scrubbing fluid. Particularly preferably, the scrubbing section has trays, particularly valve trays or bubble cap trays.

[0295] In a preferred embodiment, the internal structure consists of irregular filler and / or regular filler. The filler height (irregular filler / regular filler) is preferably in the range of 1 to 10 m, more preferably 2 to 8 m, and most preferably 3 to 6 m.

[0296] In a particularly preferred embodiment, the rescrubbing zone has trays, especially valve trays or bubble cap trays, and the number of trays is preferably in the range of 2 to 10 trays, more preferably 2 to 8 trays, and most preferably 2 to 6 trays.

[0297] The scrubbing fluid can be introduced into or above the upper region of the rescrubbing zone.

[0298] The scrubbing solution used is generally aqueous or a slightly acidic aqueous solution, especially water. The temperature of the scrubbing solution is generally in the range of 10 to 60°C, preferably in the range of 20 to 55°C, and more preferably in the range of 30 to 40°C.

[0299] In the rescrubbing zone, any residual entrained amines can be scrubbed off from the absorbent so that the acidic off-gas GS exiting the regeneration column is essentially free of amines. In the rescrubbing zone, contact with a lower-temperature scrubbing agent can lead to the condensation of some of the vaporized water, thus further reducing the moisture content of the gas stream obtained at the top of the regeneration column.

[0300] Condensation step: In a preferred embodiment of the present invention, the acidic gas stream GS from the regeneration tower is introduced into the condensation step.

[0301] In the condensation step, the water-containing condensate is condensed and exits the gaseous stream (condensate outlet). The uncondensed gaseous phase is preferably discharged to the compression step, as will be further described below.

[0302] The condensation step is preferably carried out so that the gaseous stream GS from step c) is guided through one or more condensers (top condensers of the regenerating column). The top condenser generally comprises a heat exchanger and a vessel (phase separation vessel) from which the liquid phase can be separated from the gas phase. However, the heat exchanger and the vessel may be integrated into a single component.

[0303] The top condenser of a regeneration tower is generally operated so that acidic gases remain primarily in the gas phase while water condenses.

[0304] The top condensers used in regenerative towers include, for example, condensers with cooling coils or helical tubes, jacketed tube condensers, and shell-and-tube heat exchangers.

[0305] The top condenser of a regenerating column is generally operated at temperatures in the range of 10 to 60°C, preferably 20 to 55°C, and more preferably 30 to 40°C.

[0306] In a preferred embodiment, the gaseous stream GS from step c) is guided through a top condenser of one regeneration column.

[0307] Optionally, a scrubbing fluid, as described above, can be added to the regeneration column along with the condensate from the condensation step. This can be done through the same supply point, or the scrubbing fluid can be introduced through a separate supply point.

[0308] Compression and / or liquefaction step: The fluid stream GS preferably contains CO2.

[0309] To prevent such CO2 from being released into the atmosphere, it is preferably sequestered in a suitable storage location.

[0310] Isolation generally requires compressing the gaseous CO2 stream (GS) and optionally cooling it into a fluid, which can be transported through a pipeline to a destination or as a chemical substance to a destination where it is utilized for further use. Typical CO2 pressures in pipelines for transport are 70–200 bar, preferably 90–150 bar. Typical CO2 pressures for transport by ship, truck, or train are 5–50 bar, preferably 6–40 bar, more preferably 7–35 bar.

[0311] Compression is typically affected by one or more compressors. A compressor is typically configured to receive CO2 containing a gaseous stream GS and compress the gaseous stream to obtain a compressed fluid stream CFS.

[0312] Compressors are typically positive displacement compressors or dynamic compressors. Positive displacement compressors include reciprocating compressors that use a piston driven by a crankshaft to deliver fluid at a higher pressure. Reciprocating compressors can be single-stage or multi-stage. Positive displacement compressors also include rotary screw compressors, conical screw compressors, rotary vane compressors, rolling piston compressors, or scroll compressors.

[0313] The compressor can also be a dynamic compressor, such as a centrifugal compressor or an axial flow compressor.

[0314] Preferably, the compressor is a rotary screw compressor, a centrifugal compressor, a piston compressor, or an axial flow compressor.

[0315] After compression, or after each compression step in the compressor, the fluid stream CFS is preferably passed through one or more heat exchangers to dissipate heat from the compressed fluid or to utilize the heat of compression as a heat source to heat other processes or other steps in the gas processing process.

[0316] Alternatively, compression can be supplemented by one or more additional cooling steps to liquefy the CO2. The CO2 can be cooled in a heat exchanger, which is an evaporator for a heat transfer material, preferably liquid ammonia. The evaporated heat transfer material is then compressed, cooled, and expanded in a conventional cooling circuit. Two or more cooling circuits can also be combined in series, thereby reducing the energy consumption for cooling.

[0317] Furthermore, the CO2 can be compressed and cooled by external water, expanded to transport temperature, and then compressed again. Unliquefied CO2 is preferably separated and recycled back into the compression step. Energy consumption can be reduced by performing compression and depressurization (evaporation) in several steps.

[0318] Drying and other purification steps: Generally, it is preferable to dry the CO2-containing stream GS. Drying can be performed before, after, or after one or more of the compression step or cooling step.

[0319] Drying is preferably carried out in the form of pressure swing adsorption (PSA), more preferably in the form of temperature swing adsorption (TSA), or in the form of a glycol drying operation.

[0320] PSA or TSA can be carried out by methods known to those skilled in the art. Standard modified procedures are described, for example, in Nag, Ashis, “Distillation and Hydrocarbon Processing Practices”, PennWell 2016, ISBN 978-1-59370-343-1, or in A. Terrigeol, GPA Europe, Annual Conference, Berlin, Germany, 23rd-25th May, 2012 (https: / / www.cecachemicals.com / export / sites / ceca / .content / medias / downloads / products / dtm / molecular-sieves-contaminants-effects-consequences-and-mitigation.pdf).

[0321] In PSA or TSA, it is preferable to use zeolite, activated carbon, or molecular sieves.

[0322] In PSA or TSA, it is preferable to use molecular sieves as a solid adsorbent.

[0323] In glycol drying operations, it is preferable to use liquid absorbents such as monoethylene glycol (MEG), diethylene glycol (DEG), triethylene glycol (TEG), or tetraethylene glycol (TREG). TEG is particularly preferred as the liquid absorbent.

[0324] Glycol drying operations can be carried out by process modifications known to those skilled in the art. Examples of glycol drying are similarly described, for example, in Nag, Ashis, “Distillation and Hydrocarbon Processing Practices”, PennWell 2016, ISBN 978-1-59370-343-1.

[0325] Similarly, other components such as carbonyl sulfide (COS) and hydrogen sulfide can be removed by installing additional filters and adsorption towers.

[0326] Transportation, storage, and utilization: The fluid stream CFS is preferably transported to its storage location or end-use. CO2 can be transported via pipeline or by means of transport such as trucks, trains, or ships.

[0327] Suitable storage locations include depleted oil tanks, gas reservoirs, tunnels, and suitable geological formations such as saline or other rock formations.

[0328] CO2 can also be used in the food, petroleum, and chemical industries.

[0329] A preferred use of CO2 in the food industry is the carbonization of beverages.

[0330] Other uses of recovered carbon dioxide include enhanced petroleum recovery, conversion into fuels, cement, minerals, or chemicals, or use as a material for fire extinguishers, as a solvent, or as an inert gas or refrigerant.

[0331] Recycling step d): According to the present invention, the regenerated absorbent A3 obtained at the bottom of the regeneration column from step c) is returned to the absorption step b).

[0332] The regenerated absorbent is preferably recycled at one of the supply points for the regenerated absorbent in the absorption tower described above.

[0333] summary: The method of the present invention makes it possible to utilize the thermal energy inherent in the thermal stream HS1, in particular the fluid stream FS1, to provide energy for the energy-intensive regeneration step c).

[0334] Using two or more heat pumps connected in series has the advantage that the thermal energy from the heat stream HS1, particularly the fluid stream FS1, can be increased to a level that can generate steam in the heat pump HP2, which can then be used to transfer heat to the regeneration step c). Thus, the stream generated in the heat pump HP2 can substantially replace the process steam that is typically required as a heat source in the regeneration step c). Therefore, using two heat pumps in series can replace the need to install a separate process steam generation process at the site of the acid gas removal unit, or the need for a steam turbine such as a back pressure turbine or extraction condensate turbine to generate process steam. Thus, the present invention is particularly useful when process steam is not readily available at the site of the acid gas removal unit. However, even where process steam is readily available, the method according to the present invention may be useful as an alternative method for generating process steam, as it allows potentially limited process steam resources to be used for other purposes or reduces power plant power losses associated with process steam generation. In addition, the method of the present invention is an interesting alternative in the design of new power plants coupled with acid gas removal units for carbon capture, as it can reduce the need to divert energy for steam generation to power the recycling step. Furthermore, the method of the present invention is a useful method for electrifying steam generation so that the steam required in the amine gas treatment process can be supplied by "green" electricity from renewable resources.

[0335] In a preferred embodiment of the present invention, the final heat transfer material HTM of the last heat pump HP in series is water. In this embodiment, steam can be generated as the heat transfer material stream to the reboiler. By using water as the final heat transfer material, process flexibility is greatly improved because excess steam can be diverted to other steam consumption units, or steam shortages can be compensated for by other steam supply units, such as an internal steam supply network. In this way, fluctuations in the supply stream FS2 to the absorption tower can be compensated for at least partially. Such fluctuations may arise from a decrease in demand for the processes that generate the heat stream HS1, fluid stream FS1, or fluid stream FS2. This may occur when the increased availability of renewable wind and solar energy leads to a decrease in the demand for fossil fuel-provided energy.

[0336] In a preferred embodiment of the present invention, thermal energy from a gaseous heat stream HS1, particularly a fluid stream FS1, is transferred to a regeneration step via an intermediate cooling loop comprising a direct contact cooler DCC and a cooling material CM. Direct heat exchange has the advantage of increasing the exchange area between the two fluid streams HS1 and CMS1, thereby reducing thermal resistance and maximizing thermal efficiency. In addition, direct heat exchangers generally have lower operating and capital costs than indirect heat exchangers due to their high heat transfer rate per unit volume and because contamination and corrosion are not typically a problem. Furthermore, expensive equipment such as blowers or fans required to transport fluid streams FS1 and FS2 in indirect gas-liquid heat exchangers can usually be reduced or even eliminated in direct heat exchangers compared to indirect heat exchangers because the pressure drop in direct heat exchangers is smaller.

[0337] The specific efficiency of the method of the present invention is obtained in the following cases: - When water is used as the cooling medium in the cooling medium streams CMS1 and CMS2. - When using ammonia, butane, or R1233zd(e) as the heat transfer material HTM1. - When water is used as the heat transfer material HTM2.

[0338] When using this combination of cooling material and heat transfer material, a particularly high value of the heat pump's coefficient of performance can be achieved, and a particularly flexible process can be realized.

[0339] In a preferred embodiment of the present invention, the method of the present invention can be combined with an additional heat pump designed to transfer thermal energy from other heat sources present in the gas processing process.

[0340] Other heat sources include, but are not limited to, the heat sources mentioned above, and include, but are not limited to, the following: - The heat absorbed in the absorption tower. This can be utilized in an intercooler or by integrating a heat exchanger into the absorption tower. - If a pump and cooler are installed in the rescrubbing zone, the heat absorbed in the rescrubbing zone at the top of the absorption tower. - The heat of condensation of condensates at the top of an absorption or regeneration tower. - The heat of compression generated in the compression step when compressing a gaseous stream GS into a supercritical fluid.

[0341] Using these additional measures could further reduce the energy requirements for carbon capture and storage, and as a result help reduce the diversion of electricity from power plants to gas processing units.

[0342] Second aspect - Apparatus for generating a deoxidized fluid stream In a second aspect, the present invention relates to an apparatus for deoxidizing a fluid stream as described in claim 17. [Brief explanation of the drawing]

[0343] [Figure 1] A preferred apparatus capable of carrying out the method of the present invention is shown. [Figure 2]A preferred apparatus capable of carrying out the method of the present invention is shown. [Figure 3] A preferred apparatus capable of carrying out the method of the present invention is shown. [Figure 4] A preferred apparatus capable of carrying out the method of the present invention is shown. [Modes for carrying out the invention]

[0344] A preferred apparatus capable of carrying out the method of the present invention is shown in Figures 1 to 4.

[0345] Each drawing shows a device for deoxidizing a fluid stream, a) An absorption tower, a. Inlet for the fluid stream FS2, b. Outlet for deoxidized fluid stream FS3, c. Inlet for absorbent stream A1, d. Inlet for recycled absorbent stream A3, e. Outlet for the absorbed absorbent stream A2 An absorption tower having, b) A regeneration tower, a. Inlet for absorbent stream A2, b. Outlet for recycled absorbent stream A3, c. Outlet for acid gas stream GS A regeneration tower having, c) Heat pump HP1, a. Heat exchanger HE1, - A first inlet for heat stream HS1 and an outlet for heat stream HS2, or a first inlet for cooling medium stream CMS2 and an outlet for cooling medium stream CMS3, - A second inlet for the heat transfer medium stream HTMS1 and a second outlet for the heat transfer medium stream HTMS2 A heat exchanger HE1 has, b. One or more compressors connected in series, wherein the inlet of the first compressor is connected to a second outlet for a heat transfer medium stream HTMS2 from a heat exchanger HE1, and the outlet of the last compressor in the series has an outlet for a compressed heat transfer medium stream HTMS3. The heat pump HP1 is equipped with, d) A heat pump HP2 connected in series to a heat pump HP1 by a heat exchanger HE2 having a first inlet for a heat transfer medium stream HTMS3 and an outlet for a heat transfer medium stream HTMS4, and a second inlet for a second heat transfer medium stream SHTMS1 and a second outlet for a second heat transfer medium stream SHTMS2, wherein the heat pump HP2 is further, a. One or more compressors connected in series, wherein the inlet of the first compressor is connected to a second outlet for a heat transfer medium stream SHTMS2 from a heat exchanger HE2, and the outlet of the last compressor in the series has an outlet for a compressed heat transfer medium stream SHTMS3. b. To increase the amount of gaseous heat transfer material HTM2 that can be generated, one or more optional supply points for additional heat transfer material HTM2 between compression steps (this embodiment is particularly preferred when the heat transfer material HTM2 is water in order to increase the amount of steam that can be generated in the heat pump HP2), c. Heat exchanger HE-R, d. Heat exchanger HE-R having an inlet for a second heat transfer medium stream SHTMS3 and an outlet for a second heat transfer material stream SHTMS4 Equipped with a heat pump HP2 and In an apparatus for deoxidizing a fluid stream, the following is provided: The apparatus shows a heat exchanger HE-R having an inlet for absorbent stream AS1 connected to a regeneration tower and an outlet for absorbent stream AS2, also connected to a regeneration tower.

[0346] Figure 1 shows one embodiment of a device suitable for the direct transfer of thermal energy from a heat stream HS1 to a heat exchanger HE1 of a heat pump HP1, wherein the inlet of the heat exchanger HE1 is configured to directly receive the heat stream HS1.

[0347] Figure 2 shows one embodiment of a device suitable for direct transfer of thermal energy from a heat stream HS1, wherein the heat stream HS1 is a fluid stream FS1.

[0348] Figure 3 shows one embodiment of a device suitable for indirect heat transfer of thermal energy via an intermediate cooling circuit comprising a heat exchanger HE-C from a heat stream HS1, in this case a fluid stream FS1, to a heat exchanger HE1 of a heat pump HP1, wherein the inlet of the heat exchanger HE1 is configured to accept a cooling medium stream CMS2. Figure 3 further includes a heat exchanger HE-C comprising an inlet for the heat stream HS1, in this case FS1, an outlet for the heat stream HS2, in this case a fluid stream FS2, an inlet for the cooling medium stream CMS1, and an outlet for the cooling medium stream CMS2. In Figure 3, the heat exchanger HE-C is configured as a direct contact cooler, which constitutes a preferred embodiment of the present invention.

[0349] Figure 4 shows a preferred embodiment that differs from Figure 3 in that the heat pump HP2 is configured as an open-loop heat pump and preferably operates using water as the heat transfer material HTM2.

[0350] In all diagrams, the absorption tower is configured as an absorption column.

[0351] The absorption column preferably has an absorption zone. In relation to the present invention, the absorption zone is considered to be the section of the absorption column in which the fluid stream makes mass transfer contact with the absorbent. To improve contact and provide a large mass transfer interface, the absorption zone preferably comprises an internal structure, preferably an irregular packing, a regular packing, and / or a tray.

[0352] In columns with irregular or regular packing, the absorption zone is preferably divided into 2 to 4 packing sections that are separated from each other and stacked by a support tray and a holding tray and / or a distribution tray.

[0353] If the absorption zone is equipped with irregular or regular packing, the height of the regular / irregular packing in the absorption zone is preferably in the range of 5 to 20 m, more preferably in the range of 6 to 15 m, and most preferably in the range of 8 to 14 m.

[0354] If the absorption zone includes trays, the number of trays in the absorption zone is preferably in the range of 8 to 30 trays, more preferably in the range of 12 to 25 trays, and most preferably in the range of 15 to 23 trays.

[0355] Preferably, an inlet for the fluid stream FS2 to be deoxidized is located below the absorption zone or in the lower region of the absorption zone.

[0356] Unused absorbent A1 may be supplied through an inlet located in the upper region of the absorption zone or above the absorption zone. The supply of unused absorbent may also include the supply of individual components of the absorbent (such as supply water).

[0357] The regenerated absorbent A3 may be supplied through the same inlet, or similarly through an inlet located in the upper region of the absorption zone or above the absorption zone.

[0358] Preferably above the absorption zone, preferably at the top of the absorption column, there is an outlet for the deoxidized fluid stream FS3.

[0359] A demister (not shown) is preferably mounted in the region of the withdrawal point of the deoxidized fluid stream.

[0360] In a particularly preferred embodiment, a supply point for the scrubbing agent is located in or above the upper region of the absorption zone (not shown).

[0361] In very specific embodiments, the absorption column comprises an additional rescrubbing zone above the absorption zone (not shown). The rescrubbing zone generally consists of a section of the absorption column in the form of a rectification section located above the supply point for the absorbent. The rescrubbing zone preferably has irregular packing, regular packing, and / or trays to enhance contact between the fluid stream and the scrubbing liquid. The rescrubbing zone particularly has trays, especially valve trays, bubble cap trays, Thormann trays, or sieve trays.

[0362] Preferably, a supply point (not shown) for the scrubbing agent is located above the rescrubbing zone. The rescrubbing zone preferably comprises 1 to 7 trays, more preferably 2 to 6 trays, most preferably 3 to 5 trays, or includes a packing height (irregular or regular packing) of preferably 1 to 6 m, more preferably 2 to 5 m, most preferably 2 to 3 m.

[0363] A recovery tray (not shown) may be placed beneath the rescrubbing zone, where the scrubbing fluid can be recovered and recycled. Here, recycling is generally influenced by a pump (not shown) that transports the scrubbing fluid from the recovery tray to a supply point. In the case of recycling, the scrubbing fluid may be cooled by a heat exchanger (not shown).

[0364] Preferably, a liquid outlet for the absorbed absorbent A2 is located in the lower region of the absorption tower.

[0365] In a preferred embodiment, a heat exchanger HE-CF is located between the liquid outlet for the absorbed absorbent in the absorption tower and the feed outlet for the absorbed absorbent in the regeneration tower. The heating medium used in this heat exchanger is preferably the recycled stream of regenerated absorbent A3 from the bottom of the regeneration tower to the absorption tower. In this preferred embodiment, the overall energy demand of the process can be reduced.

[0366] The heat exchanger HE-CF may be configured as a flat-plate heat exchanger or a shell-and-tube heat exchanger. The heating medium used in the heat exchanger is preferably a bottom stream from the regeneration tower.

[0367] In the drawing, the outlet for the absorbent A2 taken in from the absorption tower is preferably connected to the regeneration tower via a pipeline through a heat exchanger.

[0368] In all drawings, the regeneration column preferably comprises a regeneration zone, an evaporator, a feed inlet for the absorbed absorbent A2, a liquid outlet (outlet) at the bottom of the regeneration column for at least partially regenerated absorbent A3, a rescrubbing zone (not shown), and an outlet for the extraction of an acidic gas stream GS in the top region of the regeneration column.

[0369] In this context, the regeneration zone is considered to be the region of the regeneration tower where the absorbed absorbent comes into contact with the steam generated by the reboiler.

[0370] To improve contact and provide a large mass transfer interface, the regeneration zone preferably comprises internal structures, preferably irregular packing, regular packing, and / or trays.

[0371] In columns with irregular or regular packing, the regeneration zone is preferably divided into 2 to 4 packing sections that are separated from each other and stacked by a support tray and a holding tray and / or a distribution tray.

[0372] If the regeneration zone is equipped with irregular or regular packing, the height of the irregular / regular packing in the regeneration zone is preferably in the range of 5 to 15 m, more preferably in the range of 6 to 12 m, and most preferably in the range of 8 to 12 m.

[0373] If the regeneration zone includes trays, the number of trays in the regeneration zone is preferably in the range of 10 to 30 trays, more preferably in the range of 15 to 25 trays, and most preferably in the range of 17 to 23 trays.

[0374] The supply inlet for the absorbed absorbent A2 is preferably located above or below the regeneration zone.

[0375] The regeneration towers in Figures 1 and 2 are further equipped with a reboiler HE-R.

[0376] The reboiler is preferably a kettle-type reboiler, a natural circulation evaporator, or a forced circulation evaporator.

[0377] The reboiler HE-R is preferably connected via a pipeline to a liquid outlet at the bottom of the regeneration column to introduce the absorbent stream AS1 into the reboiler HE-R. The bottom of the column generally refers to the area below the regeneration zone.

[0378] The absorbent stream AS2 is typically a vapor-liquid mixture generated in the reboiler and is preferably introduced into the lower region of the regenerating column via a supply point that is above the liquid outlet at the bottom of the column but below the regeneration zone.

[0379] In a more preferred embodiment, the bottom of the regeneration tower is divided by a recovery tray (not shown). The absorbent recovered there is supplied to a DC-AC heat exchanger HE-CF. Stream AS2 is preferably recycled to the regeneration tower below the recovery tray.

[0380] In all drawings, the regeneration tower preferably includes an outlet for the gaseous stream GS formed during regeneration. The outlet for the gaseous stream GS formed during regeneration is preferably located in the top region of the regeneration tower. Preferably, a demister (not shown) is present in the region of the outlet.

[0381] The regeneration tower in the drawing preferably includes a rescrubbing zone (not shown) having internal structures. The internal structures in the rescrubbing zone are preferably regular or irregular packing, and the packing height (irregular / regular packing) is preferably in the range of 1 to 10 m, more preferably in the range of 2 to 8 m, and most preferably in the range of 3 to 6 m. Alternatively, the internal structures in the rescrubbing zone are trays. More specifically, the number of trays is preferably in the range of 3 to 20, more preferably in the range of 4 to 16, and preferably 6 to 12. The trays in the scrubbing section may be, for example, valve trays, bubble cap trays, Thormann trays, or sieve trays.

[0382] In the drawings, a separate supply port for the scrubbing fluid may be located above or in the upper region of the rescrubbing zone (not shown). If an additional scrubbing fluid, such as freshwater, is supplied, it is preferable to guide this scrubbing fluid into the regeneration column together with the condensate from an additional condensation step at the top of the regeneration column. Preferably, the drawout point for the gaseous stream GS formed in the regeneration column is connected to a top condenser (not shown). The top condenser preferably comprises a heat exchanger, a vessel for phase separation (phase separation vessel), a gas drawout, and a condensate outlet. Condensers used include, for example, condensers with cooling coils or helical tubes, jacketed tube condensers, and shell-and-tube heat exchangers.

[0383] The embodiments shown in Figures 1 to 4 include two heat pumps HP1 and HP2 in series, configured to transfer thermal energy from a heat stream HS1, preferably a fluid stream FS1, to a regeneration step c).

[0384] In Figure 1, the heat stream HS1 and the heat transfer material stream HTMS1 are supplied to a heat exchanger HE1, which is preferably an indirect gas-liquid heat exchanger, to obtain a heat stream HS2 having reduced thermal energy compared to the heat stream HS1 and a heat transfer material stream HTMS2 having higher thermal energy compared to the heat transfer material stream HTMS1. In Figure 2, the heat stream HS1 is a fluid stream FS1, and the heat stream HS2 is a fluid stream FS2.

[0385] In Figures 3 and 4, the heat exchanger HE1 is configured to accept a cooling medium stream CMS2 instead of a heat stream HS1. In this embodiment, the heat exchanger HE1 is preferably an indirect heat exchanger, and more preferably an evaporator.

[0386] In the drawing, the outlet of heat exchanger HE1 is configured to supply the heat transfer material stream HTMS2 to a compressor, preferably a rotary screw compressor, centrifugal compressor, piston compressor, or axial flow compressor, where the heat transfer material stream HTMS2 is compressed to obtain a heat transfer material stream HTMS3, which is preferably connected to the inlet of heat exchanger HE2 via a pipeline. In heat exchanger HE2, thermal energy from the heat transfer material stream HTMS3 from heat pump HP1 is transferred to a second heat transfer material stream HTMS1 of heat pump HP2. Heat exchanger HE2 is preferably an indirect heat exchanger.

[0387] The heat exchanger HE2 is provided with an additional outlet for a second heat transfer material stream SHTMS2. The second heat transfer material stream SHTMS2 is preferably moved via a pipeline to a second compressor, preferably a rotary screw compressor, centrifugal compressor, or axial flow compressor, to obtain a second heat transfer material SHTMS3. The compressor outlet for the second heat transfer material stream SHTMS3 is preferably connected to the inlet of the heat exchanger HE-R, which is configured to be a reboiler for a regeneration tower. In the heat exchanger HE-R, thermal energy is transferred from the second heat transfer material stream SHTM3 to the absorbent stream AS1 to obtain an absorbent stream AS2 having higher thermal energy compared to the absorbent stream AS1, and a second heat transfer material stream SHTMS4 having reduced thermal energy compared to the second heat transfer material stream SHTMS3. As described above, the outlet for the absorbent stream AS2 of the heat exchanger HE-R is preferably connected to the inlet below the regeneration zone of the regeneration tower.

[0388] In the drawing, the heat pump HP1 comprises a heat exchanger HE1, a heat exchanger HE2, and a compressor connected to heat exchangers HE1 and HE2.

[0389] In Figures 1 and 2, the heat pump H2 comprises a heat exchanger HE2, a heat exchanger HE-C, and a compressor connected to heat exchangers HE2 and HE-C.

[0390] Heat pumps HP1 and HP2 are connected in series, meaning that heat exchanger HE2 is both a condenser for the heat transfer material HTM1 of heat pump HP1 and an evaporator for the heat transfer material HTM2 of heat pump HP2.

[0391] Figures 1 to 3 show heat pumps HP1 and HP2, which further include optional equipment configured to perform optional recycling steps R1 and R2. This additional equipment includes means for expanding the respective heat transfer material streams HTMS4 and SHTMS4 to obtain the respective heat transfer material streams HTMS5 and SHTMS5, which preferably have the same temperature and pressure as the respective heat transfer material streams HTMS1 and SHTMS1, and can therefore be recycled to the inlets of the respective heat exchangers HE1 and HE2. The means for expanding the respective heat transfer material streams is preferably a thermal expansion valve.

[0392] Figure 4 shows heat pumps HP1 and HP2 in series, where heat pump HP2 operates as an open-loop heat pump not configured to include a recycling step R2. This embodiment is particularly preferred when the heat transfer material HTM2 of the heat pump HP is water.

[0393] The apparatus shown in Figures 1 to 4 can be operated according to the process conditions described in the first embodiment of the present invention.

[0394] Third aspect - Use of a series-connected heat pump to transfer thermal energy from the fluid stream to the regeneration step In a third aspect, the present invention relates to the use described in claim 18.

[0395] The use of two or more heat pumps connected in series has the advantage of being able to raise the thermal energy contained in the heat stream HS1, particularly the fluid stream FS1, to the level necessary to dissipate the absorbed acidic gas from the partially absorbed absorbent.

[0396] The present invention is illustrated by the following examples.

[0397] This embodiment is based on calculations performed using a simulation model. The phase equilibrium was described using a model by Pitzer (KS Pitzer, Activity Coefficients in Electrolyte Solutions 2nd ed., CRC Press, 1991, Chapter 3, Ion Interaction Approach: Theory). The absorption process simulation was described using a mass transfer-based method, the details of which are described by Asprion (Asprion, N.:Nonequilibrium Rate-Based Simulation of Reactive Systems: Simulation Model, Heat Transfer, and Influence of Film Discretization, Ind. Eng. Chem.Res. (2006) 45 (6), 2054-2069).

[0398] The present invention is illustrated by the following examples.

[0399] Example 1 is based on calculations performed using a simulation model. The phase equilibrium of the carbon recovery section was described using a model by Pitzer (KS Pitzer, Activity Coefficients in Electrolyte Solutions 2nd ed., CRC Press, 1991, Chapter 3, Ion Interaction Approach: Theory). The absorption process simulation was described using a mass transfer-based method, the details of which are described by Asprion (Asprion, N.: Nonequilibrium Rate-Based Simulation of Reactive Systems: Simulation Model, Heat Transfer, and Influence of Film Discretization, Ind. Eng. Chem.Res. (2006) 45 (6), 2054-2069).

[0400] The necessary thermodynamic data can be obtained for heat pumps from PC-SAFT (NH3), (Gross, J.; Sadowksi, G.: Industrial & engineering chemistry research, 2002, 41 (22) 5510), and for water from NBS tables (NBS / NCR Steam Tables by L. Haar, et al., New York: Hemisphere Publishing, 1984).

[0401] Example 1 is based on the process scheme shown in Figure 4, in which heat is transferred from the fluid stream FS1 to a series of heat pumps HP1 and HP2 via an intermediate cooling cycle including a direct contact cooler DCC, and in this process scheme, heat pump HP2 is configured as an open-loop heat pump with slight modifications as described further below.

[0402] A fluid stream FS1 with a composition shown in Table A below, a temperature of 70°C, and a pressure of 1.01 bar, at a flow rate of 1389 t / h, is supplied to the bottom of a heat exchanger HE-C configured as a direct contact cooler (DCC). In HE-C, FS1 is brought into counterflow contact with water as a cooling medium stream CMS1 to obtain a fluid stream FS2 with a temperature of 35°C and a pressure of 0.99 bar and a flow rate of 124.1 t / h. Fluid stream FS2 is then slightly compressed to a pressure of 1.07 bar and a temperature of 43.4°C before being introduced into absorption step b). CMS1 is introduced to the top of HE-C at a temperature of 40°C and a pressure of 2.25 bar and a flow rate of 3233.3 t / h. Thermal energy is transferred from fluid stream FS1 to cooling medium stream CMS1 to obtain cooling medium stream CMS2 at the bottom of HE-C. A small amount of CMS2 (150.7 t / h) is purged from the process. 3275 t / h of CMS2, with a temperature of 61.4°C and a pressure of 1.01 bar, is used as a heat stream HS1 for a series heat pump comprising a first heat pump HP1 using ammonia as the heat transfer material HTM1, and a second heat pump HP2 using water as the heat transfer material HTM2. Heat pump HP1 is designed as a closed-loop heat pump including a regeneration step. Heat pump HP2 is designed as an open-loop heat pump. Thermal energy from heat stream HS1 (CMS2) is transferred through the evaporator HE1 of heat pump HP1 to a heat transfer material stream HTMS1 with a flow rate of 408.19 t / h at a temperature of 37.7°C and a pressure of 14.54 bar, to obtain a gaseous heat transfer material stream HTMS2 with a flow rate of 408.19 t / h, a temperature of 37.6°C, and a pressure of 14.49 bar. Furthermore, a cooled cooling medium stream CMS3 is obtained, which is further cooled to a temperature of 32°C in an additional cooler and pumped to the heat exchanger HE-C at a pressure of 4.5 bar. The heat transfer material stream HTMS2 is compressed in a compressor to obtain a heat transfer material stream HTMS3 at a pressure of 75.48 bar and a temperature of 197.6°C.The heat transfer material stream HTMS3 is fed into heat exchanger HE2, which is the condenser for heat pump HP1 and the evaporator for heat pump HP2, to obtain a cooled liquid heat transfer material stream HTMS4 with a temperature of 109.6°C and a pressure of 75.43 bar. To close the loop and recycle the heat transfer material stream HTMS4 to heat exchanger HE1, the heat transfer material stream HTMS4 is expanded to obtain a cooled heat transfer material stream HTMS5 with a temperature of 37.7°C and a pressure of 14.54 bar. The heat transfer material stream HTMS5 is partially liquid (246.8 t / h) and gaseous (161.4 t / h) and is recycled to heat exchanger HE1 as heat transfer material stream HTMS1. In heat exchanger HE2, thermal energy is transferred from heat transfer material stream HTMS3 to a second heat transfer material stream SHTMS1 having a flow rate of 174.3 t / h, a pressure of 5 bar, and a temperature of 99.6°C, to obtain a second heat transfer material stream SHTMS2 having a flow rate of 174.3 t / h, a pressure of 1 bar, and a temperature of 99.6°C. The second heat transfer material stream SHTMS2 is compressed in three stages, each stage including one compressor. In the first compressor, the pressure is increased to 1.5 bar and the temperature is increased to 146.1°C. After the first compressor, an additional stream of water is added with a flow rate of 3.8 t / h, a temperature of 99.6°C, and a pressure of 5 bar to obtain a second heat transfer material stream SHTSM3* having a flow rate of 178.1 t / h, a pressure of 1.5 bar, and a temperature of 121.4°C. In the second compressor, the second heat transfer material stream STMS3* is further compressed to a pressure of 2.3 bar and a temperature of 134.1°C. Another stream of water having a temperature of 99.6°C and a pressure of 5 bar is added at a flow rate of 5.8 t / h to obtain a second heat transfer material stream SHTM3** with a flow rate of 183.9 t / h, a temperature of 134.1°C, and a pressure of 2.3 bar. In the third compressor, the second heat transfer material stream SHTMS** is further compressed to obtain a second heat transfer material stream SHTMS*** with a pressure of 3.4 bar and a temperature of 184.3°C.Furthermore, an additional stream of water having a temperature of 99.6°C, a pressure of 5 bar, and a flow rate of 6.1 t / h is added to the second heat transfer material stream SHTMS*** to obtain a second heat transfer material stream SHTMS3 having a temperature of 147.8°C, a pressure of 3.4 bar, and a flow rate of 190.0 t / h. The thermal energy from the second heat transfer material stream SHTMS3 is transferred to the reboiler of the absorption tower to maintain a temperature of 127.3°C at the bottom of the absorption tower. A lower temperature second heat transfer material stream SHTMS4 is obtained, having a temperature of 137.3°C and a pressure of 3.34 bar.

[0403] The coefficient of performance (COP), a measure of the performance of a heat pump system, is 2.34.

[0404] The heat pump HP2 was operated as an open-loop heat pump, meaning the second heat transfer material stream SHTMS4 was not recycled to the heat exchanger HE2. Alternatively, the heat pump HP2 could be operated as a closed-loop heat pump, and at least a portion of the second heat transfer material stream SHTMS4 could be recycled, for example, as stream SHTMS1 to the heat exchanger HE2, or as an additional stream of heat transfer material HTM2, after the pressure and temperature were adjusted by additional expansion, cooling, or compression steps to adjust the characteristics of stream HTMS4 to match the respective input streams.

[0405] The example demonstrates that the energy contained in the low-temperature fluid stream FS1 can be effectively utilized to heat the regeneration step c).

[0406] To achieve this with a conventional heat pump, a heat transfer material must be found that undergoes a phase transition at the temperature and pressure of the heat exchanger HE1, and is compressed to obtain the high temperature required in the regeneration step c), particularly in the reboiler. Ammonia is unsuitable because it needs to be compressed to a supercritical pressure within the heat exchanger HE2.

[0407] In Example 1, only the amount of steam required in regeneration step c) is generated. Since the process of the present invention generates steam, it can be supplemented by another steam source, or excess steam can be supplied to other consumption units. Alternatively, excess steam can be diffused into the environment.

[0408] [Table 1]

Claims

1. A method for generating a deoxidized fluid stream FS3 from a fluid stream containing at least one acidic gas, a) A heat energy transfer step in which thermal energy is transferred from heat stream HS1 to regeneration step c) to obtain heat stream HS2 having reduced thermal energy compared to heat stream HS1, b) An absorption step in which the fluid stream FS2 is brought into contact with the absorbent A1 in the absorption tower to obtain the absorbent A2 that has absorbed the acidic gas and the fluid stream FS3 that has been at least partially deoxidized, c) A regeneration step in which at least a portion of the absorbent A2 obtained from step b) is regenerated in a regeneration tower to obtain a gaseous stream GS containing at least partially regenerated absorbent A3 and at least one acidic gas, d) A recycling step in which at least a substream of the recycled absorbent A3 from step c) is recycled to the absorption step b) In a method including, A method wherein the heat energy transfer step a) includes two or more heat pumps connected in series.

2. The method according to claim 1, wherein the stream HS1 is a fluid stream FS1 and the stream HS2 is the fluid stream FS2.

3. The aforementioned heat energy transfer step, 1) In the heat exchanger HE-1 of the first heat pump HP1, thermal energy is transferred from the heat stream HS1 to the heat transfer medium stream HTMS1 of the heat transfer material HTM1 to obtain a heat transfer medium stream HTMS2 having increased thermal energy compared to the heat transfer medium stream HTMS1, 2) The step of compressing the heat transfer medium stream HTMS2 in the first heat pump HP1 to obtain a heat transfer medium stream HTMS3 having a higher pressure than the heat transfer medium stream HTMS2, 3) In the heat exchanger HE-2 of the second heat pump HP2, thermal energy is transferred from the heat transfer medium stream HTMS3 of the first heat pump HP1 to the second heat transfer medium stream SHTMS1 of the second heat transfer material HTM2, thereby obtaining a second heat transfer medium stream SHTMS2 having increased thermal energy compared to the second heat transfer medium stream SHTMS1, and a heat transfer medium stream HTMS4 having a decreased thermal energy content compared to the heat transfer medium stream HTMS3. 4) The step of compressing the second heat transfer medium stream SHTMS2 in the second heat pump HP2 to obtain a second heat transfer medium stream SHTMS3 having a higher pressure than the second heat transfer medium stream SHTMS2, 5) A step of transferring thermal energy from the second heat transfer medium stream SHTMS3 of the second heat pump HP2 to the regeneration step c) to obtain a second heat transfer medium stream SHTMS4 having a reduced thermal energy content compared to SHTMS3. The method according to claim 1 or 2, including the method described in claim 1 or 2.

4. The method according to claim 3, wherein step 5) is performed by transferring thermal energy in the heat exchanger HE-R from the second heat transfer medium stream SHTMS4 to the absorbent stream AS1 drawn from the regeneration tower in step c) to obtain an absorbent stream AS2 having increased thermal energy compared to the absorbent stream AS1, and supplying AS2 to the regeneration tower in step c).

5. The method according to claim 4, wherein the heat exchanger HE-R is the reboiler of the regenerative tower.

6. The method according to claim 3, wherein the transfer of thermal energy from the second heat transfer material stream HTMS3 to the regeneration step c) in step 5) is carried out in a heat exchanger HE-R in which the absorbed absorbent A2 obtained in step b) is heated before entering the regeneration step c).

7. The method according to any one of claims 3 to 5, further comprising an additional recycling step R1) in which the heat transfer material stream HTMS4 obtained in step 3) is expanded to obtain a heat transfer medium stream HTMS5 having a lower pressure compared to the heat transfer material stream HTMS4, and this is at least partially recycled back to step 1) as the heat transfer material stream HTMS1.

8. The method according to any one of claims 3 to 7, further comprising an additional recycling step R2) to expand the second heat transfer material stream SHTMS4 obtained in step 5) to obtain a second heat transfer medium stream SHTMS5 having a reduced pressure compared to the second heat transfer material stream SHTMS4 and being at least partially recycled in step 3) as the second heat transfer material stream SHTMS1.

9. The method according to any one of claims 3 to 8, wherein in step 4), the compression of the second heat transfer medium stream 2 comprises two or more compression steps.

10. The method according to any one of claims 3 to 9, wherein after one or more compression steps, an additional heat transfer material HTM2 is added in liquid form.

11. The method according to any one of claims 2 to 10, wherein the temperature of the fluid stream FS1 is in the range of 60 to 400°C.

12. The method according to any one of claims 2 to 11, wherein the fluid stream FS1 is desulfurized in the fluid stream desulfurization step before the heat energy transfer step a).

13. The method according to claim 12, wherein the temperature of the fluid stream 1 after the desulfurization step is in the range of 60 to 200°C.

14. The method according to any one of claims 1 to 13, wherein the heat transfer material HTM1 is selected from the group consisting of ammonia, butane, R1233zd(e), R1224yd(z), air, CO2, water, chlorofluorocarbon, hydrochlorofluorocarbon, hydrofluorocarbon, hydrofluoroolefin, hydrochlorofluoroolefin, hydrocarbon, perfluoro(2-methyl-3-pentanone), and mixtures of two or more thereof, and / or the heat transfer material HTM2 is water.

15. In step 1), the transfer of thermal energy from the fluid stream FS1 to the heat transfer medium stream HTMS1 of the first heat pump HP1 is as follows: 1a) Transferring thermal energy from FS1 to the cooling medium stream CMS1 to obtain a) a fluid stream FS2 having a reduced thermal energy content compared to FS1, and b) a cooling medium stream CMS2 having an increased thermal energy content compared to CMS1. 1b) Transfer at least a portion of the thermal energy contained in the cooling medium CMS2 to the heat transfer medium stream HTMS1, thereby obtaining a heat transfer medium stream HTMS2 having increased thermal energy compared to HTMS1, and a cooling medium stream having decreased thermal energy compared to CMS2, which is at least partially recycled back to step 1a) as CMS1. The method according to any one of claims 2 to 14, including the method described in any one of claims 2 to 14.

16. The method according to claim 14, wherein the transfer of thermal energy from the fluid stream FS1 to the cooling medium stream CMS1 is performed in a heat exchanger HE-C, and the heat exchanger HE-C is a direct contact type cooler.

17. A device for deoxidizing a fluid stream, a) An absorption tower, a. Inlet for fluid stream FS2, b. Outlet for the deoxidized fluid stream FS3, c. Inlet for absorbent stream A1, d. Inlet for the recycled absorbent stream A3, e. Outlet for absorbent stream A2 An absorption tower having, b) A regeneration tower, a. Inlet for absorbent stream A2, b. An outlet for the regenerated absorbent stream A3, c. Outlet for acid gas stream GS and A regeneration tower having, c) Heat pump HP1, a. Heat exchanger HE1, A first inlet for stream HS1 and an outlet for stream HS2, A second inlet for the heat transfer medium stream HTMS1 and a second outlet for the heat transfer medium stream HTMS2 A heat exchanger HE1 has, b. One or more compressors connected in series, wherein the inlet of the first compressor is connected to the second outlet for the heat transfer medium stream HTMS2 from the heat exchanger HE1, and the outlet of the last compressor in the series has an outlet for the compressed heat transfer medium stream HTMS3. The heat pump HP1 is equipped with, d) A heat pump HP2 connected in series to a heat pump HP1 by a heat exchanger HE2 having a first inlet for a heat transfer medium stream HTMS3 and an outlet for a heat transfer medium stream HTMS4, and a second inlet for a second heat transfer medium stream SHTMS1 and a second outlet for a second heat transfer medium stream SHTMS2, wherein the heat pump HP2 is further, a. One or more compressors connected in series, wherein the inlet of the first compressor is connected to the second outlet for the heat transfer medium stream SHTMS2 from the heat exchanger HE2, and the outlet of the last compressor in the series of compressors has an outlet for the compressed heat transfer medium stream SHTMS3, b. Heat exchanger HE-R, c. A heat exchanger HE-R having an inlet for a second heat transfer medium stream SHTMS3 and an outlet for a second heat transfer material stream SHTMS4 Equipped with a heat pump HP2 and In an apparatus for deoxidizing a fluid stream, the following is provided: The apparatus wherein the heat exchanger HE-R has an inlet for an absorbent stream AS1 connected to the regeneration tower and an outlet for an absorbent stream AS2 also connected to the regeneration tower.

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