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, including an improved 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 an improved heat pump. In a third aspect, the present invention relates to the use of an improved heat pump 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 an improved heat pump for transferring 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 an improved heat pump.

[0003] In a third aspect, the present invention relates to the use of an improved heat pump 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 those that absorb and emit infrared radiation in the wavelength range emitted by the Earth, and thus contribute to global warming. The concentration of CO2 in the atmosphere has risen from about 280 ppm in the pre-industrial era around 1750 to about 421 ppm in 2022. Approximately two-thirds of the total carbon dioxide emissions are due to the combustion of fossil fuels.

[0006] Most climate change mitigation measures require substantial financial investment and have implementation periods of several years or decades.

[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 short time scale, and thus can directly affect climate change. Carbon dioxide can be directly recovered from industrial sources such as cement manufacturing, natural gas processing, and ammonia and hydrogen production, or from power plants powered by fossil fuels or biomass fuels. The current achievable carbon recovery rate from the exhaust gas of carbon-based fuels is 80-95%.

[0008] The recovered carbon dioxide can be removed from the atmosphere by carbon sequestration or carbon storage in suitable geological formations such as depleted oil reservoirs, gas storage layers, mines, and saline or other rock layers. Before transporting the carbon dioxide to its final storage location and injecting it underground, the carbon dioxide is usually compressed to a high pressure of about 100 bar. Other uses of the recovered carbon dioxide are enhanced oil recovery or conversion into fuels, 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. Almost all 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] 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]

[0032] 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 devise a flexible process that can accommodate fluctuations in the flow rates of the heat stream HS1, fluid stream FS1, or FS2. [Means for solving the problem]

[0033] 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, a) A heat energy transfer step, (i) In the heat exchanger HE1, heat energy is transferred from the heat stream HS1 to the liquid heat transfer material stream HTMS1 of the heat transfer material HTM1 to obtain the liquid heat transfer material stream HTMS2a, (ii) A step of expanding the heat transfer medium stream HTMS2a in one or more expansion steps to obtain a gaseous heat transfer material stream HTMS2b(g) having a lower pressure than the heat transfer material stream HTMS2a, (iii) A step of compressing the heat transfer material stream HTMS2b(g) in one or more compression steps to obtain a gaseous heat transfer material stream HTMS3 having a higher pressure than the heat transfer material stream HTMS2b, (iv) The step of transferring thermal energy from the heat transfer material stream HTMS3 to regenerate step c) to obtain the heat transfer material stream HTMS4. A heat energy transfer step, 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) This includes methods.

[0034] Figures 1-4 show process configurations suitable for carrying out the process of the present invention.

[0035] Heat energy transfer step a) The method of the present invention includes transferring thermal energy from the heat stream HS1 to regeneration step c).

[0036] The heat stream HS1 is preferably generated from a heat source HS.

[0037] The heat source HS can be any heat source from the gas processing process or an external heat source outside the gas processing process.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] Fluid Stream FS1 In a preferred embodiment of the present invention, stream HS1 is a fluid stream FS1.

[0043] 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.

[0044] 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 NOx It is possible that such a thing exists.

[0045] 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.

[0046] 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.

[0047] 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 the improved heat pump according to the present invention.

[0048] The pressure in the fluid stream FS1 typically depends on the source of the fluid stream FS1, as will be further outlined below.

[0049] Preferably, the fluid stream 1 is exhaust gas.

[0050] The exhaust gas is preferably obtained by burning fossil fuels such as coal, natural gas, and petroleum, or carbon-based fuels such as biomass raw materials derived from plants, algae, or animals.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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).

[0056] 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.

[0057] In addition, even after the exhaust gas desulfurization step, the exhaust gas contains small amounts of other gases, particularly nitrogen oxides (NOx) and sulfur oxides (SOx).

[0058] 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%.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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).

[0063] 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.

[0064] 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.

[0065] 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 at least hydrogen, carbon monoxide, and some carbon dioxide, as well as water.

[0066] 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.

[0067] 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.

[0068] The heat energy transfer step a) of the present invention is (i) In the heat exchanger HE1, heat energy is transferred from the heat stream HS1 to the liquid heat transfer material stream HTMS1 of the heat transfer material HTM1 to obtain the liquid heat transfer material stream HTMS2a, (ii) A step of expanding the heat transfer medium stream HTMS2a in one or more expansion steps to obtain a gaseous heat transfer material stream HTMS2b(g) having a lower pressure than the heat transfer material stream HTMS2a, (iii) A step of compressing the heat transfer material stream HTMS2b(g) in one or more compression steps to obtain a gaseous heat transfer material stream HTMS3 having a higher pressure than the heat transfer material stream HTMS2b, (iv) The step of transferring thermal energy from the heat transfer material stream HTMS3 to regenerate step c) to obtain the heat transfer material stream HTMS4. Includes.

[0069] heat pump The method according to the present invention is preferably carried out in a so-called improved heat pump, where steps (i) and (ii) essentially replace the conventional evaporator of the heat pump, in which thermal energy is transferred from a heat stream to a liquid heat transfer material stream HTMS1 to obtain a gaseous heat transfer material stream HTMS2.

[0070] The use of the so-called improved heat pump, including steps (i) and (ii), has the advantage of being able to utilize the heat stream HS1, which has a relatively low temperature, to transfer energy to the regenerated step c). The use of the improved heat pump also enables the generation of a larger volume of steam compared to conventional heat pumps. Therefore, the use of the so-called improved heat pump allows for increased design flexibility and improved thermal integration in the design of the acid gas removal unit.

[0071] The improved 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, an improved 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 improved heat pump is typically, - A step in which thermal energy is transferred from a heat source to a heat transfer material, usually by a heat exchanger, wherein the heat exchanger is usually designed as a liquid-liquid heat exchanger. - A step of expanding a heat transfer material in one or more expansion steps to evaporate a liquid heat transfer material, - 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] Improved open-loop heat pumps have the advantage of being able to utilize media from various sources, particularly water, which is normally already present in amine gas treatment processes and poses no problems in handling and disposal.

[0075] An improved closed-loop heat pump typically features a closed-loop heat transfer medium between the heat source and the heat sink. This is usually accomplished by an additional recycling step for the heat transfer medium, such as the recycling step R1 for the improved heat pump HP1 described further below. This recycling step R1 enables the recycling of the heat transfer material, significantly reducing the need to replenish the heat transfer material, 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, and in such cases, it is desirable to house these materials in a closed cycle.

[0076] In a preferred embodiment, the improved heat pump HP1 is designed as an open-loop improved heat pump, and the heat transfer material HTM1 is water. In such an embodiment, the heat transfer material stream HTMS4 is not recycled directly. Instead, the heat transfer material HTM1 is supplied from another source, e.g., a river, lake, or water supply network, or from a different process that provides water capable of receiving thermal energy from the heat stream HS1. The heat transfer material stream HTMS4 can be disposed of into the environment directly or via a wastewater treatment plant.

[0077] The improved heat pump HP1 is preferably, - A heat exchanger HE1 transfers thermal energy from a heat stream HS1 to a liquid heat transfer medium stream HTMS1 of a heat pump HP to obtain a liquid heat transfer material stream HTMS2a having increased thermal energy compared to the heat transfer medium stream HTMS1. - An expansion means for expanding a liquid heat transfer material HTMS2a to obtain a gaseous heat transfer material stream HTMS2b, - One or more compressors for compressing a heat transfer material stream HTMS2b 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 HTMS2b, - Heat exchanger HE-R for transferring thermal energy from the heat transfer material stream HTMS3 of the first heat pump HP1 to regenerated step c) It is equipped with.

[0078] In addition, if HP1 is an improved closed-loop heat pump, HP1 is preferably, - One or more additional expansion and / or cooling steps to expand and / or cool the heat transfer material stream HTMS4 to obtain a heat transfer material stream having the properties of the heat transfer material stream HTMS2a. Includes.

[0079] Heat transfer material HTM1 The heat transfer material HTM1 is a working fluid used in an improved heat pump HP1 to transport thermal energy from the heat exchanger HE1 to regeneration step c).

[0080] Preferably, the heat transfer material HTM1 is selected such that it does not undergo a phase transition in the heat exchanger HE1 in step i), but can undergo a phase transition from liquid to gaseous state during expansion in step ii).

[0081] 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).

[0082] Heat transfer material streams 1-4 are streams of heat transfer material 1 at different stages of the improved heat pump HP1. - The heat transfer material stream HTMS1 is the stream of heat transfer material HTM1 that enters step i), - The heat transfer material stream HTMS2a is a stream of heat transfer material HTM1 that exits step i) and enters step ii), - The heat transfer material stream HTMS2b is the stream that exits step ii) and enters compression step iii), - The heat transfer material stream HTMS3 is a stream of heat transfer material HTM1 that exits compression step iii) and enters step iv). - The heat transfer material stream HTMS4 is the stream of heat transfer material HTM1 exiting step iv).

[0083] Direct heat transfer from HS1 to HTMS1 via heat exchanger HE1 in step i) In step i) of the present invention, thermal energy from the heat stream HS1 is transferred to the heat transfer medium stream HTMS1 of the heat pump HP1 to obtain a heat transfer medium stream HTMS2a having increased thermal energy compared to the heat transfer medium stream HTMS1.

[0084] In a preferred embodiment of the present invention, the thermal energy of the hot stream HS1 is directly transferred to the heat transfer material stream HTMS1 of the improved heat pump HP1.

[0085] The transfer of thermal energy from the hot stream HS1 to the heat transfer material stream HTMS1 is usually affected by the heat exchanger HE1.

[0086] The exchanger HE1 is usually a device used to transfer thermal energy in the form of heat between the hot stream HS1 and the heat transfer medium stream HTMS1 to obtain a heat transfer medium stream HTMS2a having increased thermal energy compared to the heat transfer medium HTMS1 and a hot stream HS2 having decreased thermal energy compared to the hot stream HS1.

[0087] In a preferred embodiment, the heat exchanger HE1 is an indirect heat exchanger in which the transfer of heat between the hot stream HS1 and the heat transfer medium stream HTMS1 occurs indirectly through a partition or transiently through the wall without any physical contact or mass transfer between the two streams (indirect heat exchange).

[0088] When the heat exchanger HE1 is an indirect heat exchanger, HE1 usually - an inlet for the hot stream HS1 having a pressure p HS1 and temperature T HS1 and an outlet for the hot stream HS2 having a pressure p when exiting the outlet HS2 and temperature T HS2 and an inlet for the heat transfer medium stream HTMS1 having a pressure p when entering the inlet HTMS1 and temperature T HTMS1 and an outlet for the hot stream HS2 having a pressure p when exiting the outlet HTMS2 and temperature T HTMS2 and is provided with an outlet for the hot stream HS2. and.

[0089] Preferably, the heat exchanger HE1 is an indirect heat exchanger in which heat is transferred from the heat stream HS1 to the liquid heat transfer material stream HTMS1.

[0090] Preferably, the indirect heat exchanger is a tubular heat exchanger, preferably a shell-tube heat exchanger, a double-pipe heat exchanger, a drip-type heat exchanger, or a flat-plate heat exchanger. Most preferably, the heat exchanger HE1 is a shell-tube heat exchanger or a flat-plate heat exchanger.

[0091] When HS1 is a gaseous stream, the heat exchanger HE1 is preferably a gas-liquid heat exchanger, such as the one 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 the one described in Chapter 2.1.3.1 of the same document, or a finned-tube heat exchanger such as the one described in Chapter 2.1.3.2 of the same document.

[0092] The heat exchanger HE1 is preferably designed to satisfy the following requirements: - Temperature T HTMS1 is, T HS1 Preferably 1 to 100K, more preferably 2 to 60K, and most preferably 5 to 30K 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. - The heat transfer material stream HTMS1 does not undergo a phase transition from liquid to gaseous state in the heat exchanger HE1.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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 improved heat pump HP1.

[0097] Figures 1 to 4 show an embodiment of direct heat exchange from the heat stream HS1 to the heat transfer material stream HTMS1.

[0098] Indirect heat exchange from HS1 to HTMS1 via an intermediate cooling step In a preferred embodiment of the present invention, the heat stream HS1 in heat transfer step i) in which thermal energy is transferred from the heat stream HS1 to the heat transfer medium stream HTMS1 is the cooling medium stream CMS2.

[0099] The transfer of thermal energy from the heat stream HS1 preferably includes step ia) transferring thermal energy from the heat stream HS1 to the cooling medium stream CMS1 to obtain a) a heat stream HS2 having a reduced thermal energy content compared to the heat stream HS1, and b) a cooling medium stream CMS2 having an increased thermal energy content compared to the CMS1.

[0100] This step is preferably followed by ib) transferring 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 HTMS2a 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).

[0101] Step ia) - Transfer of thermal energy via heat exchanger HE-C In step ia), the transfer of thermal energy from the heat stream HS1 to the cooling medium stream CMS1 is preferably influenced by the heat exchanger HE-C.

[0102] 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.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] 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). xWhen 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.

[0108] 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.

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] 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.

[0120] 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.

[0121] Step ib) 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 ib) 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 HTMS2a having increased thermal energy compared to HTMS1 and cooling medium stream CMS3 having decreased thermal energy compared to CMS2.

[0122] In step 1b), CMS2 functions as the heat source stream HS1 of the improved 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.

[0123] 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 HTMS2a and temperature T HTMS2a Outlet for heat transfer medium stream HTMS2a having It is equipped with.

[0124] In the case of indirect heat transfer via an intermediate cooling cycle, the heat exchanger HE1 is preferably an indirect heat exchanger, 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.

[0125] In the case of indirect heat transfer via an intercooling cycle, the heat exchanger HE1 is preferably designed to satisfy the following requirements: - The heat transfer material stream HTMS1 does not undergo a phase transition. - Temperature T CMS2The temperature range is 25 to 120°C, preferably 30 to 100°C, and more preferably 40 to 70°C. - Temperature T HTMS2a is, T HTMS1 This is approximately 0.1 to 50K higher, preferably 0.5 to 25K, and more preferably 1 to 10K higher.

[0126] In both the direct transfer via step i) and the indirect heat transfer via the intermediate cooling cycle in steps ia) and ib), thermal energy is transferred to the heat transfer material stream HTMS1 to obtain a heat transfer stream HTMS2a having increased thermal energy compared to the heat transfer medium stream HTMS1.

[0127] Recycling of the cooling medium stream CMS3 After the transfer of thermal energy from the cooling medium stream CMS2 to the heat transfer material stream HTMS1, a cooling medium stream CMS3 is obtained that has reduced thermal energy compared to the cooling medium stream CMS2. The cooling medium stream CMS3 is preferably recycled as the cooling medium stream CMS1 in step i) or step ia). Therefore, in order to accept a cooling medium stream having the characteristics of the cooling medium stream CMS1, the cooling medium stream CMS3 may need to be subjected to one or more additional cooling steps, for example, in a water cooler or air cooler.

[0128] Step ii) Expansion from HTMS2a to HTMS2b After transferring thermal energy to the heat transfer material stream HTMS2a, the liquid heat transfer material stream HTMS2a is expanded in one or more expansion steps to obtain a gaseous heat transfer material stream HTMS2b(g) having a lower pressure than the heat transfer material stream HTMS2a.

[0129] The expansion step is preferably carried out by means suitable for influencing such expansion. The expansion is preferably p HTMS2aThis is carried out as flash evaporation of the heat transfer material stream HTMS2a via an expansion valve or throttle valve into a container having a pressure lower than . The container preferably has a liquid outlet and a vapor outlet. More preferably, the container is a flash drum. The stream HTMS2a(l) of the heat transfer material HTMS2a, which remains in liquid form after evaporation, is preferably recycled to step i) as a heat transfer material stream HTMS1, as further described below.

[0130] The pressure in evaporation step ii) is preferably reduced to a value of 10 to 900 millibars, preferably 30 to 700 millibars, and more preferably 50 to 300 millibars.

[0131] The pressure drop can affect one or more evaporation steps.

[0132] The pressure drop typically results in a temperature drop of preferably 2-30K, more preferably 3-20K, and most preferably 5-15K, and partial evaporation of the heat transfer material stream HTMS2b to obtain a gaseous heat transfer material stream HTMS2a(g), while the remaining portion of the heat transfer material stream HTMS2a remains in a liquid state, obtaining a liquid heat transfer material stream HTMS2b(l). Due to the pressure drop, typically about 0.5-10 weight percent, preferably 1-8 weight percent, and more preferably 2-5 weight percent of the original mass of the heat transfer material stream HTMS2a undergoes a phase transition to a gaseous state. The liquid portion of the heat transfer material stream HTMS2b(l) is preferably recycled as the heat transfer material stream HTMS1 to the heat exchanger HE1 in step i) or ia). One or more compression and / or cooling steps may be required to impart the properties of the heat transfer material stream HTMS1 to the liquid portion of the heat transfer material stream HTMS2b(l). Preferably, the heat transfer material stream HTMS2b(l) is cooled in a heat exchanger HE-RS, which is preferably a water cooler or an air cooler.

[0133] Step iii) Compressing HTMS2b to HTMS3 After expanding the heat transfer medium stream HTMS2a to obtain a gaseous heat transfer material stream HTMS2b(g), the thermal energy is further transferred, preferably in step iii), by compressing the gaseous heat transfer medium stream HTMS2b(g) in the improved heat pump HP1 to obtain a heat transfer medium stream HTMS3 having a higher pressure than the gaseous heat transfer medium stream HTMS2b(g).

[0134] Compression is preferably affected in the compressor.

[0135] A compressor is a device used to increase the pressure of a fluid that is at least partially gaseous.

[0136] 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.

[0137] The compressor can also be a dynamic compressor, such as a centrifugal compressor or an axial flow compressor.

[0138] Preferably, the compressor is a rotary screw compressor, a centrifugal compressor, a piston compressor, or an axial flow compressor.

[0139] Compression can be performed using one compressor or a series of compressors, depending on the desired pressure increase of the heat transfer material HTM1.

[0140] The heat transfer material HTM1 is under pressure p HTMS2b and temperature T HTSM2b The gaseous heat transfer material stream HTMS2b(g) enters the compression step, and pressure p HTMS3 and temperature T HTMS3The heat transfer material HTMS3 exits the compression step.

[0141] Pressure rise Δp(p HTMS3 -p HTMS2b Typically, the pressure rise Δp is selected so that the temperature of the heat transfer medium stream rises to the temperature required in regeneration step b). Preferably, the pressure rise Δp is selected so that a temperature of 100-150°C, preferably 105-140°C, and most preferably 110-130°C is achieved in the heat exchanger HE-R, and the heat exchanger HE-R is preferably the reboiler of the regeneration tower in step b).

[0142] In a preferred embodiment, compression step iii) is performed in a series of two or more compressors, and the heat transfer material HTM1 is water. In this embodiment, an additional stream of heat transfer material HTM1 is supplied after each of the series compressors to increase the amount of gaseous heat transfer material HTM1 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 HTM1 is energetically advantageous in a scenario in which the same amount of gaseous heat transfer material HTM1 is generated compared to a scenario in which the additional heat transfer material HTM1 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. In addition, the injection of additional heat transfer material HTM1 results in a reduction in volumetric flow rate and a reduction in the power requirements of subsequent compressors in the successive compression stages. The temperature of the added water is typically in the range of 20-99°C, preferably 40-90°C, and more preferably 60-80°C, and the pressure of the added water is typically in the range of 1-10 bar, preferably 2-8 bar, and more preferably 3-6 bar. Preferably, an amount equivalent to 2-10 weight percent, more preferably 3-8 weight percent, of the original mass of the gaseous heat transfer material stream HTMS2b(g) is added after each compression step. The addition of water has a cooling effect, which must be taken into consideration in the compression step to achieve the final temperature required to maintain the temperature in the reboiler of the absorption tower as described above.

[0143] Step iv) Transfer of thermal energy from HTSM3 to regeneration step c) According to a preferred embodiment of the present invention, in step iv), thermal energy is transferred from the heat transfer medium stream HTMS3 to the regeneration step c) by transferring the thermal energy to the regeneration step c) to obtain a heat transfer medium stream HTMS4 having a reduced thermal energy content compared to HTMS3.

[0144] The transfer of thermal energy from the heat transfer material stream HTMS3 to regeneration step c) can occur indirectly or directly, as will be further explained below.

[0145] Indirect heat transfer to regeneration step c) In a preferred embodiment of the present invention, the transfer of thermal energy from the heat transfer material stream HTMS3 to regeneration step c) takes place in a heat exchanger HE-R, where the absorbent A2 obtained in step b) is heated before entering regeneration step c).

[0146] Heat exchanger HE-R may be replaced or added to a direct-to-alternating-voltage heat exchanger used to transfer heat from the regenerated absorbent A3 to the absorbed absorbent A2 before entering regeneration step c).

[0147] The heat exchanger HE-R is preferably an indirect heat exchanger.

[0148] 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 HTMS3 and temperature T HTMS3 An inlet for the heat transfer medium stream HTMS3 having, - Pressure p when exiting the outlet HTMS4 and temperature T HTMS4 Outlet for heat transfer medium stream HTMS4 having It is equipped with.

[0149] More preferably, the heat exchanger HE-R is a shell-and-tube exchanger or a plate exchanger.

[0150] 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.

[0151] Direct heat transfer to regeneration step c) In the most preferred embodiment, thermal energy is transferred directly from the heat transfer medium stream HTMS3 to the bottom of the regeneration tower in regeneration step c).

[0152] 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.

[0153] 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.

[0154] The reboiler also includes an inlet into which the heat transfer material stream HTMS3 enters and an outlet into which the second heat transfer material stream HTMS4 exits the reboiler.

[0155] 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.

[0156] 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.

[0157] Further details relating to regeneration step c) and recycling step d) will be described in later sections of this specification.

[0158] Open-loop heat pump The improved heat pump according to Embodiment C preferably operates as an open-loop heat pump; therefore, the heat transfer material stream HTMS4 is preferably not recycled. The advantages of an open-loop heat pump have already been described. The heat transfer material stream HTMS4 can be disposed of into the environment, for example, through wastewater purification, or can be used as a heat source for other processes or units at the AGRU site. If the heat transfer material stream HTMS4 is not recycled, it may be necessary to replenish the heat stream material stream HTMS2a with an amount of heat transfer material HTM1 corresponding to the amount of heat transfer material stream HTMS4 that is not recycled.

[0159] Recycling Step The heat transfer material HTM4 in Embodiment C can also be recycled.

[0160] Preferably, the heat transfer material stream HTMS4 is recycled to the heat transfer material stream HTMS2a before the evaporation means.

[0161] Recycling may require an additional cooling step to cool the heat transfer material stream HTMS4 obtained at the outlet of the heat exchanger HE-R before recycling it as heat transfer material stream HTMS2a.

[0162] 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.

[0163] Absorbent: The absorbent contains at least one amine.

[0164] The following amines are preferred. i) Amine of formula (I): NR 1 (R 2 )2(I) In the formula, R 1 R is selected from C2-C6-hydroxyalkyl groups, C1-C6-alkoxy-C2-C6-alkyl groups, hydroxy-C1-C6-alkoxy-C2-C6-alkyl groups, and 1-piperazinyl-C2-C6-alkyl groups. 2 This is independently selected from H, C1-C6-alkyl groups, and C2-C6-hydroxyalkyl groups. ii) Amine of formula (II): R 3 R 4 NX-NR 5 R 6 (II) In the formula, R 3 , R 4 , R 5 , and R 6 H is independently selected from C1-C6-alkyl groups, C2-C6-hydroxyalkyl groups, C1-C6-alkoxy-C2-C6-alkyl groups, and C2-C6-aminoalkyl groups, and X is a C2-C6-alkylene group, -X 1 -NR 7 -X 2 - or -X 1 -OX 2 - and in the formula, X 1 and X 2 These are independently C2-C6 alkylene groups, and R 7 is H, C1-C6-alkyl group, C2-C6-hydroxyalkyl group, or C2-C6-aminoalkyl group. iii) A 5- to 7-membered saturated heterocycle having at least one nitrogen atom in the ring and potentially containing one or two further heteroatoms selected from nitrogen and oxygen. iv) A mixture of those.

[0165] 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.

[0166] 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.

[0167] Further amines that can be introduced into this process are tert-butylaminopropanediol, tert-butylaminoethoxyethylmorpholine, tert-butylaminoethylmorpholine, methoxyethoxyethoxyethyl-tert-butylamine, and tert-butylaminoethylpyrrolidone.

[0168] 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).

[0169] 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.

[0170] 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.

[0171] 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.

[0172] 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.

[0173] Absorbents generally contain 10% to 60% by weight of amines.

[0174] In one embodiment, the absorbent comprises methyldiethanolamine, which is a tertiary amine, and piperazine, which is an activator.

[0175] In a preferred embodiment, the absorbent is A) At least one cyclic amine compound having only tertiary amine groups, B) At least one cyclic amine compound having at least one sterically unhindered secondary amine group Includes, The total concentration of A) + B) is 10-60% by weight.

[0176] Such absorbents are disclosed in European Patent No. 2391435. Most preferably, amine A) is triethylenediamine (TEDA) and activator amine B) is piperazine.

[0177] The absorbent may additionally contain a physical solvent. Suitable physical solvents include, for example, N-methylpyrrolidone, tetramethylene sulfone, and oligoethylene glycol dialkyl ethers (such as oligoethylene glycol methyl isopropyl ether (SEPASOLV MPE) and oligoethylene glycol dimethyl ether (SELEXOL)). The physical solvent is generally present in the absorbent in an amount of 1% to 60% by weight, preferably 10% to 50% by weight, and particularly 20% to 40% by weight.

[0178] In preferred embodiments, the absorbent comprises less than 10% by weight (e.g., less than 5% by weight, particularly less than 2% by weight) of an inorganic basic salt (e.g., potassium carbonate).

[0179] Absorbents may also contain additives such as corrosion inhibitors, antioxidants, enzymes, and defoamers. Generally, the amount of such additives ranges from about 0.01% to 3% by weight of the absorbent.

[0180] The absorption tower may be supplied with unused absorbent material, or it may be supplied with absorbent material recycled in recycling step c). Supplying unused absorbent material means that the components of the absorbent material have not yet gone through steps b) to d). Supplying recycled absorbent material requires that at least a portion of the components of the absorbent material have gone through steps b) to d).

[0181] 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.

[0182] Absorption tower: The fluid stream FS2 is preferably brought into contact with the absorbent in the absorption tower in step b).

[0183] The absorber is preferably an absorption tower or an absorption column, such as a column or tray column having irregular or regular packing.

[0184] An absorption tower generally comprises an absorption zone and, optionally, a rescrubbing zone.

[0185] The absorption zone is considered to be the section of the absorption column where the fluid stream makes mass transfer contact with the absorbent.

[0186] The fluid stream is preferably in contact with the absorbent in a countercurrent manner within the absorption zone.

[0187] 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.).

[0188] 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.

[0189] 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.

[0190] 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.

[0191] 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.

[0192] The pressure inside the absorption tower depends on the pressure and type of the fluid stream FS2 entering the absorption tower.

[0193] 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.

[0194] 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.

[0195] 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.

[0196] An absorption tower may have one or more supply points for the absorbent being introduced. For example, an absorption tower may have a supply point for unused absorbent A1 and a supply point for regenerated absorbent A3. Alternatively, unused and regenerated absorbent may be supplied together to the absorption tower through a single supply point. The one or more supply points are preferably located above the absorption zone or in the upper region of the absorption zone. Individual components of the absorbent (such as makeup water) may also be supplied through the supply point for unused absorbent.

[0197] If the absorption tower has an optional rescrubbing zone, the supply port is preferably located between the absorption tower zone and the rescrubbing zone.

[0198] Contact between the fluid stream and the absorbent in the absorption zone yields a fluid stream FS3 that is at least partially deoxidized and an absorbent that has already absorbed the acidic gas.

[0199] The upper region of the absorption tower typically contains a draw-out point for the deoxidized fluid stream FS3. A demister may be installed in the draw-out point region to separate any liquid residue of the absorbent or scrubbing agent from the outflowing fluid stream.

[0200] Generally, in the lower region of the absorption tower, preferably at the bottom of the tower, there is a draw-out point for the absorbed absorbent FS2.

[0201] The fluid stream FS3, which has been at least partially deoxidized, may optionally be brought into contact with the scrubbing fluid in one or more rescrubbing zones (collectively referred to as “rescrubbing zones”).

[0202] The scrubbing fluid is more preferably an aqueous liquid. The scrubbing fluid may be a process-specific liquid, i.e., an aqueous liquid obtained elsewhere in the process, or an aqueous liquid supplied from an external source. Preferably, the scrubbing fluid includes condensate formed in a downstream cooling operation on the deoxidized fluid stream (referred to as top condensate in the absorption tower) and / or fresh water.

[0203] The rescrubbing zone is generally the section of the absorption tower located above the point where the absorbent is supplied.

[0204] 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.

[0205] 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.

[0206] 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.

[0207] 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.

[0208] 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.

[0209] The deoxidized fluid stream FS3 described above is preferably drawn out through a drawout point at the top of the absorption tower.

[0210] Optionally, the deoxidized fluid stream FS3 can be guided through a condenser.

[0211] 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.

[0212] 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.

[0213] 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.

[0214] Step b) yields absorbent A2 that has at least partially absorbed the acidic gas.

[0215] The absorbed absorbent A2 can be supplied directly to regeneration step c).

[0216] Inflation step (optional): In a particular embodiment of the process of the present invention, the expansion step is performed on the absorbent A2 first, before the absorbent A2 is introduced into the regeneration step c).

[0217] In the expansion step, the incorporated adsorbent A2 is generally guided into one or more expansion containers.

[0218] 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.

[0219] 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.

[0220] Expansion generally results in the desorption of so-called flash gas. This flash gas can be returned to the absorption by a compressor, incinerated for energy generation, or incinerated in place.

[0221] 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 an expansion vessel operating at a pressure preferably 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.

[0222] 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).

[0223] 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.

[0224] 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).

[0225] 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.

[0226] The gaseous stream GS may contain residual water that was not separated in the rescrubbing zone.

[0227] 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.

[0228] 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).

[0229] 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.

[0230] Play tower: According to the present invention, the regeneration step is performed in a regeneration tower.

[0231] Regeneration columns are generally configured as emission columns.

[0232] The regeneration tower preferably comprises a regeneration zone and a reboiler.

[0233] 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.

[0234] Generally, a liquid outlet for the recycled absorbent A3 is located at the bottom of the regeneration tower.

[0235] 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.

[0236] The regeneration tower generally has a regeneration zone disposed above the bottom of the tower and below the re-scrubbing zone. In this regard, the regeneration zone is regarded as the area of the regeneration tower where the absorbed absorbent contacts the vapor generated in the reboiler.

[0237] To improve the contact and provide a large mass transfer interface, the regeneration zone generally comprises internal structures, such as random packings, structured packings, and / or trays (such as valve trays, bubble cap trays, Thormann trays, or sieve trays, etc.).

[0238] When the regeneration zone comprises structured or random packings, the height of the structured / random packings 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.

[0239] When the regeneration zone comprises 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.

[0240] In the case of a column having random or structured packings, the regeneration zone can similarly be divided into a plurality of sections, preferably 2 to 4 sections. Support trays and hold-down trays and / or distributor trays can be arranged between the sections of the regeneration zone, which improve the distribution of the liquid across the cross-section of the regeneration tower.

[0241] Generally, the absorbed absorbent A2 is preferably introduced into the regeneration tower, into the upper region of the regeneration zone, or above the regeneration zone and below the re-scrubbing zone.

[0242] In the regeneration zone, the vapor generated in the evaporator generally operates in countercurrent to the absorbent flowing downward through the regeneration zone.

[0243] The zone below the regeneration zone in the regeneration tower is generally called the bottom of the tower.

[0244] 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.

[0245] 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.

[0246] 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.

[0247] Preferably, the bottom drawout from the regenerating column is completely guided to the reboiler as an absorbent stream AS1.

[0248] Reboilers (HE-R) are typically kettle-type reboilers, natural circulation reboilers, thermal siphon reboilers, or forced circulation reboilers.

[0249] The reboiler HE-R of the regenerating tower is preferably located outside the regenerating tower and connected to the bottom outlet via a pipeline.

[0250] 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.

[0251] 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.

[0252] 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.

[0253] 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.

[0254] The rescrubbing zone generally takes the form of a section of the regeneration tower located above the regeneration zone.

[0255] 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.

[0256] 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.

[0257] 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.

[0258] The scrubbing fluid can be introduced into or above the upper region of the rescrubbing zone.

[0259] 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.

[0260] In the re-scrubbing zone, the residual amount of entrained amine can be scrubbed out from the absorbent so that the acidic off-gas GS exiting the regeneration tower is essentially amine-free. In the re-scrubbing zone, contact with a cooler scrubbing agent can result in the condensation of a portion of the vaporous water, so that the water content of the gas stream obtained at the top of the regeneration tower can be further reduced.

[0261] 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.

[0262] In the condensation step, a condensate containing water is condensed and exits from the gaseous stream (condensate outlet). The non-condensed gas phase is preferably discharged to the compression step as further described below.

[0263] The condensation step is preferably carried out such that the gaseous stream GS from step c) is guided through one or more condensers (top condenser of the regeneration tower). The top condenser of the regeneration tower generally comprises a heat exchanger and a vessel (phase separation vessel) in which the liquid phase can be separated from the gas phase. However, the heat exchanger and the vessel may be integrated into one component.

[0264] The top condenser of the regeneration tower generally operates such that the acidic gas mainly remains in the gas phase while water condenses.

[0265] The top condensers of the regeneration tower used are, for example, condensers having cooling coils or helical tubes, jacketed tube condensers, and shell-and-tube heat exchangers.

[0266] The top condensers of the regeneration tower generally operate at a temperature in the range of 10 to 60 °C, preferably 20 to 55 °C, more preferably 30 to 40 °C.

[0267] In a preferred embodiment, the gaseous stream GS from step c) is guided through the top condenser of one regeneration tower.

[0268] 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.

[0269] Compression and / or liquefaction step: The fluid stream GS preferably contains CO2.

[0270] To prevent such CO2 from being released into the atmosphere, it is preferably sequestered in a suitable storage location.

[0271] 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.

[0272] 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.

[0273] 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.

[0274] The compressor can also be a dynamic compressor, such as a centrifugal compressor or an axial flow compressor.

[0275] Preferably, the compressor is a rotary screw compressor, a centrifugal compressor, a piston compressor, or an axial flow compressor.

[0276] After compression, or after each compression step in the compressor, the compressed 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.

[0277] 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.

[0278] 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.

[0279] 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.

[0280] 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.

[0281] 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).

[0282] In PSA or TSA, it is preferable to use zeolite, activated carbon, or molecular sieves.

[0283] In PSA or TSA, it is preferable to use molecular sieves as a solid adsorbent.

[0284] 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.

[0285] 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.

[0286] Similarly, other components such as carbonyl sulfide (COS) and hydrogen sulfide can be removed by installing additional filters and adsorption towers.

[0287] Transportation, storage, and utilization: The compressed 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.

[0288] Suitable storage locations include depleted oil tanks, gas reservoirs, tunnels, and suitable geological formations such as saline or other rock formations.

[0289] CO2 can also be used in the food, petroleum, and chemical industries.

[0290] A preferred use of CO2 in the food industry is the carbonization of beverages.

[0291] Other uses of recovered carbon dioxide include enhanced petroleum recovery, conversion into fuel, cement, minerals, or chemicals, or use as a material for fire extinguishers, as a solvent, or as an inert gas or refrigerant.

[0292] 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).

[0293] The regenerated absorbent is preferably recycled at one of the supply points for the regenerated absorbent in the absorption tower described above.

[0294] 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).

[0295] The improved heat pump used in the present invention differs in essence from conventional heat pumps in which heat transfer and evaporation occur in an evaporator, by separating heat transfer and evaporation into two separate steps. This separation has the advantage that heat from a low-temperature heat source HS1 that is not hot enough to directly generate steam can be used to directly generate steam, preferably hot steam, which can then be used to transfer thermal energy to regeneration step b). The generation of hot steam, preferably hot steam, can be influenced using equipment that requires less investment. Furthermore, the operating costs of such a process are attractive.

[0296] Using an improved heat pump in which the heat transfer step and the evaporation step are two distinct steps has the advantage that the thermal energy from the heat stream HS1, in particular the fluid stream FS1, can be raised to a level in the heat pump HP1 that can be used to transfer heat to the regeneration step c) and generate steam.

[0297] Therefore, the stream generated in the heat pump HP1 can substantially replace the process steam that is normally required as a heat source in the regeneration step c). Thus, the use of the improved heat pump 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 losses in the power plant associated with process steam generation. In addition, the method of the present invention is an interesting alternative in the design of a new power plant coupled to an acid gas removal unit for carbon capture, as it can reduce the need to divert energy for steam generation to power the recycling step. In addition, 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.

[0298] 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 c) 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 usually a problem. Furthermore, expensive equipment such as blowers or fans required to transport fluid streams FS1 and FS2 in an indirect gas-liquid heat exchanger can usually be reduced or even eliminated in a direct heat exchanger compared to an indirect heat exchanger because the pressure drop in a direct heat exchanger is smaller.

[0299] 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 water is used as the heat transfer material HTM1, this combination of cooling material and heat transfer material can achieve a particularly high coefficient of performance for the heat pump.

[0300] 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.

[0301] Other heat sources include, but are not limited to, the heat source HS mentioned above. Examples of such other heat sources HS 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.

[0302] Using these additional measures could further reduce the energy requirements for carbon capture and storage, and as a result help reduce the amount of electricity diverted from power plants to gas processing units.

[0303] 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, 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 acidic gas stream GS, d. Outlet for absorbent stream AS1, e. Inlet for Absorbent Stream AS2 A regeneration tower having, c) Heat transfer system HP1, a. Heat exchanger HE1, - A first inlet for heat stream HS1 and an outlet for heat stream HS2, - A second inlet for the heat transfer medium stream HTMS1, which is essentially composed of the heat transfer material HTM, and a second outlet for the heat transfer medium stream HTMS2a. A heat exchanger HE1 has, b. Means for expanding the heat transfer material stream HTMS2a to obtain a gaseous heat transfer material stream HTMS2b having a lower pressure compared to the heat transfer material stream HTMS2a, c. 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 HTMS2b, and the outlet of the last compressor in the series has an outlet for a compressed heat transfer medium stream HTMS3. d. Heat exchanger HE-R, - A first inlet for the heat transfer medium stream HTMS3 and an outlet for the heat transfer medium stream HTMS4, - A second inlet for absorbent stream AS1 and a second outlet for absorbent stream AS2 Heat exchanger HE-R and The heat transfer system HP1 is equipped with This relates to a device that includes the following features. [Brief explanation of the drawing]

[0304] [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]

[0305] A preferred apparatus capable of carrying out the method of the present invention is shown in Figures 1 to 4.

[0306] 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.

[0307] In the heat exchanger HE1, thermal energy is transferred to the heat transfer material stream HTMS1 to obtain a liquid heat transfer material stream HTMS2a. The heat transfer material stream HTMS2a is expanded in an expansion means, here a valve and a flush container, to obtain a gaseous heat transfer material stream HTMS2b(g) and a liquid heat transfer material stream HTMS2b(l). The heat transfer material stream HTMS2b(l) is recycled back to the heat exchanger HE1. The gaseous heat transfer material stream HTMS2b(g) is subjected to a compression step, here including one compressor, to obtain a compressed heat transfer material stream HTMS3. Preferably (but not shown), the compression step includes two or more, preferably three to five, compressors. More preferably (but not shown), the apparatus according to Figure 1 includes an additional inlet configured to add additional heat transfer material HTM1 after at least one of the compression steps, at least one compressor, but preferably after all compressors. Typically, the inlet is located in a line connecting the outlet of one compressor to the inlet of another compressor. The heat transfer material stream HTMS3 is supplied to the heat exchanger HE-R, which is the reboiler of the regenerating tower in regeneration step c). HE-R is preferably configured to receive stream AS1 from the bottom of the regenerating tower and return stream AS2. In Figure 1, HE-R is the reboiler of the regenerating tower in regeneration step c). In HE-R, heat from the heat transfer material stream HTMS3 is transferred to stream AS1, resulting in stream AS2 with increased thermal energy and heat transfer material stream HTMS4 with reduced thermal energy. Several alternative forms exist for the utilization of the heat transfer material stream HTMS4 (indicated by the text box in Figure 1). In an open-loop improved heat pump, the heat transfer material stream HTMS4 is either diffused into the environment, for example via wastewater treatment, or used in an acid gas treatment process or for another heat consumption unit, rather than being recycled within the heat pump process. This is preferred when the heat transfer material HTM1 is water. Alternatively, the heat transfer material stream HTMS4 is recycled to the improved heat pump (indicated by the dashed arrow).Preferably, the heat transfer material stream HTMS4 is recycled to a feed port located before the evaporation means to supplement the heat transfer material stream HTMS2a. Alternatively, the heat transfer material stream HTMS4 is recycled to the heat exchanger HE1 as the heat transfer material stream HTMS1. Compression, expansion, or cooling steps that may be useful in imparting the properties of the heat transfer material stream HTMS1 or HTMS2a to the heat transfer material stream HTMS4 are not shown.

[0308] Figure 2 shows one embodiment of a device suitable for the direct transfer of thermal energy from a heat stream HS1, in this case a fluid stream FS1, in a heat exchanger HE1, which is a direct contact cooler (HE-C). In a direct contact cooler, heat from the fluid stream FS1 is transferred to a heat transfer material stream HTMS1 (which is the cooling medium for the direct contact cooler), receiving the cooled fluid stream FS2 and a liquid heat transfer material stream HTMS2a separated from the fluid streams FS1 and FS2. The rest of the device corresponds to Figure 1. An additional cooler HE-RS is shown to cool the liquid heat transfer material stream HTMS2b(l) obtained after the evaporation step before recycling it to its direct contact cooler. If the heat transfer material HTM1 of the improved heat pump HP1 is water, steam can be directly generated from the cooling medium of the direct contact cooler with minimal equipment.

[0309] Figure 3 is a modified version of Figure 2, in which heat from the heat stream HS1, here FS1, is transferred to the cooling medium stream CMS1 of the direct-contact cooler (HE-C) during the intermediate cooling cycle. Cooling medium stream CMS2, which has higher thermal energy than cooling medium stream CMS1, is used as the heat stream HS1 for the improved heat pump HP1, as shown in the figures above. In the heat exchanger HE1, thermal energy is transferred to the heat transfer material stream HTMS1 to obtain the liquid heat transfer material HTMS2a and the cooled cooling medium stream CMS3. The cooling medium stream CMS3 is preferably cooled in the cooler HE-RS before being recycled as the cooling medium stream CMS1 to the heat exchanger HE-C, which is configured as a direct-contact cooler.

[0310] Figure 4 shows a preferred embodiment of Figure 1, which includes two additional inlets for the heat transfer material HTM, i.e., water, after two compressors that compress the heat transfer material stream 2b(g) to obtain the compressed heat transfer material stream HTMS3. The number of compressors can be three or more (not shown).

[0311] In all diagrams, the absorption tower is configured as an absorption column.

[0312] 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.

[0313] 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.

[0314] 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.

[0315] 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.

[0316] 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.

[0317] 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).

[0318] 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.

[0319] Preferably above the absorption zone, preferably at the top of the absorption column, there is an outlet for the deoxidized fluid stream FS3.

[0320] A demister (not shown) is preferably mounted in the region of the withdrawal point of the deoxidized fluid stream.

[0321] 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).

[0322] 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.

[0323] 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.

[0324] 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).

[0325] Preferably, a liquid outlet for the absorbed absorbent A2 is located in the lower region of the absorption tower.

[0326] 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.

[0327] 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.

[0328] 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.

[0329] 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.

[0330] 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.

[0331] 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.

[0332] 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.

[0333] 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.

[0334] 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.

[0335] The supply inlet for the absorbed absorbent A2 is preferably located above or below the regeneration zone.

[0336] The regeneration tower is equipped with a reboiler HE-R.

[0337] The reboiler is preferably a kettle-type reboiler, a natural circulation evaporator, or a forced circulation evaporator.

[0338] 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.

[0339] 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.

[0340] 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.

[0341] 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.

[0342] 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.

[0343] 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.

[0344] Figure 4 shows a preferred embodiment of Figure 1, which includes two additional inlets for the heat transfer material HTM, i.e., water, after two compressors that compress the heat transfer material stream 2b(g) to obtain the compressed heat transfer material stream HTMS3. The number of compressors can be three or more (not shown).

[0345] The apparatus shown in Figures 1 to 3 can be operated according to the process conditions described in the first embodiment of the present invention.

[0346] 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 of an improved heat pump for transferring thermal energy from a heat stream HS1 to a regeneration step c) in a process according to the present invention.

[0347] In addition to the other advantages disclosed in the above sections, the use of an improved heat pump has the advantage of being able to raise the thermal energy contained in the heat stream HS1, and in particular the fluid stream FS1, to the level necessary to dissipate the absorbed acidic gas from the partially absorbed absorbent. [Examples]

[0348] The present invention is illustrated by the following examples.

[0349] Example 1 is based on calculations using a further simulation tool called EBSILON® Professional (www.ebsilon.com) which utilizes the thermodynamic package REFPROP (https: / / refprop - docs.readthedocs.io / en / latest / DLL / index.html). This tool is typically applied to simulations of power plants, but is generally applicable to all types of thermodynamic cycles.

[0350] Example 1: Example 1 is based on the process scheme shown in Figure 3, with several modifications described below.

[0351] After heat transfer from the fluid gas stream FS2 to the cooling medium stream CMS1 in the direct contact cooler (DCC or HE-C), a cooling medium stream CMS2 with a flow rate of 5500 t / h, a pressure of 1.2 bar, and a temperature of 62°C was obtained. The cooling medium stream CMS2 was supplied to the heat exchanger HE1 of the improved heat pump HP1 to obtain a cooled cooling medium stream CMS3 with a temperature of 50°C and a pressure of 1.2 bar. Stream CMS3 was further cooled in a water cooler to obtain a cooling medium stream CMS4 with a temperature of 42°C, which was recycled to the direct contact cooler as cooling medium stream CMS1. In the heat exchanger HE1, heat was transferred from the cooling medium stream CMS1 to a heat transfer material stream HTMS1 with a flow rate of 5500 t / h, a pressure of 1.2 bar, and a temperature of 46°C to obtain a heat transfer material stream HTMS2 with a temperature of 57°C and a pressure of 1.15 bar. The heat transfer material streams HTMS1 and HTMS2a are streams of the heat transfer material HTM1, which is water. The heat transfer material stream HTMS2a is expanded to a pressure of 0.1 bar to obtain the heat transfer material stream HTMS2b, which has a temperature of 46°C and a pressure of 0.1 bar. The heat transfer material stream HTMS2b consists of a liquid stream HTMS2a(l) with a flow rate of 5500 t / h and a gaseous stream HTMS2a(g) with a flow rate of 113.6 t / h. The liquid heat transfer material stream HTMS2b(l) is compressed to a pressure of 1.2 bar and then recycled to the heat exchanger HE1 as the heat transfer material stream HTMS1 to obtain a heat transfer material stream with a pressure of 1.2 bar and a temperature of 45.8°C and a flow rate of 5500 t / h. The gaseous heat transfer material stream HTMS2b(g) is supplied to the compression step. Prior to expansion, an additional stream of heat transfer material HTM1 is added to the heat transfer material stream HTMS2a at a flow rate of 1.15 bar, a temperature of 75°C, and a flow rate of 113.6 t / h to compensate for the gaseous portion of the heat transfer material stream HTMS2b supplied to the compression step and maintain the material balance of the recycling loop, including the liquid streams HTMS1 and HTMS2a.

[0352] The compression step to obtain the heat transfer material stream HTMS3 includes five compression stages, each stage including a compressor.

[0353] As described above, the gaseous portion of the heat transfer material stream HTMS2b, having a flow rate of 113.6 t / h, a temperature of 45.8°C, and a pressure of 0.1 bar, is supplied to the first compression stage to obtain a heat transfer material stream HTMS3* having a pressure of 0.2 bar and a temperature of 114.61°C. Before supplying stream HTMS3* to the second compression stage, an additional stream of heat transfer material HTM1, having a temperature of 75°C and a pressure of 5 bar, is added to stream HTMS3* at a flow rate of 3.7 t / h to obtain a heat transfer material stream HTMS3* having a flow rate of 117.3 t / h, a pressure of 0.2 bar, and a temperature of 75°C.

[0354] The heat transfer material stream HTMS3* is supplied to the second compression stage to obtain a heat transfer material stream HTMS3** with a pressure of 0.4 bar and a temperature of 149.6°C. Before supplying stream HTMS3** to the third compression stage, an additional stream of heat transfer material HTM1 with a temperature of 75°C and a pressure of 5 bar is added to stream HTMS3** at a flow rate of 6.3 t / h to obtain a heat transfer material stream HTMS3** with a flow rate of 123.62 t / h, a pressure of 0.4 bar, and a temperature of 85°C.

[0355] The heat transfer material stream HTMS3** is supplied to the third compression stage to obtain a heat transfer material stream HTMS3*** with a pressure of 0.8 bar and a temperature of 161.1°C. Before supplying stream HTMS3*** to the fourth compression stage, an additional stream of heat transfer material HTM1 with a temperature of 75°C and a pressure of 5 bar is added to stream HTMS3** at a flow rate of 6.0 t / h to obtain a heat transfer material stream HTMS3*** with a flow rate of 129.6 t / h, a pressure of 0.8 bar, and a temperature of 103°C.

[0356] The heat transfer material stream HTMS3*** is supplied to the fourth compression stage to obtain a heat transfer material stream HTMS3**** with a pressure of 1.6 bar and a temperature of 182.1°C. Before supplying stream HTMS3**** to the fifth and final compression stage, an additional stream of heat transfer material HTM1 with a temperature of 75°C and a pressure of 5 bar is added to stream HTMS3** at a flow rate of 6.5 t / h to obtain a heat transfer material stream HTMS3**** with a flow rate of 136.1 t / h, a pressure of 1.6 bar, and a temperature of 123°C.

[0357] The heat transfer material stream HTMS3**** is supplied to the fifth compression stage to obtain a heat transfer material stream HTMS3 with a pressure of 3.2 bar and a temperature of 205.2°C. Before supplying stream HTMS3 to the heat exchanger HE-R to transfer the heat to regeneration step c), an additional stream of heat transfer material HTM1 with a temperature of 75°C and a pressure of 5 bar is added to stream HTMS3 at a flow rate of 7.4 t / h to obtain a heat transfer material stream HTMS3 with a flow rate of 143.5 t / h, a pressure of 3.2 bar, and a temperature of 143°C.

[0358] Heat is transferred from the heat transfer material stream HTMS3 to the regeneration step c) in the reboiler of the regeneration tower, maintaining a temperature of 127°C at the bottom of the regeneration tower.

[0359] The performance coefficient of the heat pump is 3.57.

[0360] The heat pump operates as an open-loop heat pump without recycling the heat transfer material water to the evaporation step. However, at least a portion of the heat transfer material stream HTMS4 can ultimately be recycled to, for example, the evaporation step or compression step, after adjusting the pressure and temperature by an additional expansion step, cooling step, or compression step to adjust the properties of stream HTMS4 to each input stream such as heat transfer material stream HTMS1 or HTMS2a.

Claims

1. A method for generating a deoxidized fluid stream from a fluid stream containing at least one acidic gas, a) A heat energy transfer step, (i) In the heat exchanger HE1, heat energy is transferred from the heat stream HS1 to the liquid heat transfer material stream HTMS1 of the heat transfer material HTM1 to obtain the liquid heat transfer material stream HTMS2a, (ii) A step of expanding the heat transfer medium stream HTMS2a in one or more expansion steps to obtain a gaseous heat transfer material stream HTMS2b(g) having a lower pressure than the heat transfer material stream HTMS2a, (iii) A step of compressing the heat transfer material stream HTMS2b(g) in one or more compression steps to obtain a gaseous heat transfer material stream HTMS3 having a higher pressure than the heat transfer material stream HTMS2b, (iv) The step of transferring thermal energy from the heat transfer material stream HTMS3 to the regeneration step c) to obtain the heat transfer material stream HTMS4. A heat energy transfer step, b) An absorption step in which the fluid stream FS2 is brought into contact with the absorbent A1 in an absorption tower to obtain an absorbent A2 that has absorbed the acidic gas and a fluid stream 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) Methods that include...

2. The method according to claim 1, wherein the heat source HS1 is the fluid stream FS1 that is used in step (i) to obtain the fluid stream FS2.

3. The method according to claim 1, wherein the heat transfer material HTM1 is essentially composed of water.

4. The heat source HS1 is - Intercooler stream used to cool the fluid stream FS2 after it enters the absorption tower in step b), - A heated cooling medium stream obtained from the top condenser of the absorption tower in step b), or from the top condenser of the regeneration tower in step c), - After one or more compression steps, the fluid stream GS obtained at the top of the regeneration tower in step c) The method according to claim 1.

5. The method according to any one of claims 1 to 3, wherein the heat stream HS1 is a cooling medium stream CMS2 of a cooling material CM1, and the cooling medium stream CMS2 is generated by bringing the heat stream HS1 into contact with the cooling medium stream CMS1 in a heat exchanger HE-C.

6. The method according to claim 5, wherein the heat exchanger HE-C is a direct contact type cooler.

7. The method according to claim 5 or 6, wherein the cooling medium CM1 is water.

8. The method according to any one of claims 1 to 7, wherein an additional heat transfer material HTM1 is added after at least one of the one or more compression steps in step (iii).

9. The method according to any one of claims 1 to 8, wherein the heat transfer material stream HTMS4 is not recycled to the heat exchanger HE-1.

10. The method according to any one of claims 1 to 8, wherein the heat transfer material stream HTSM4 is cooled to obtain a cooled heat transfer material stream HTMS4 that is recycled to the heat exchanger HE-1 as a heat transfer material stream HTMS1.

11. The method according to any one of claims 1 to 10, wherein the fluid stream FS1 is exhaust gas.

12. The method according to any one of claims 1 to 11, wherein the expansion step (ii) includes expanding the heat transfer material stream HTMS 2a into an expansion vessel having a pressure lower than the pressure of the heat transfer material stream HTMS 2a prior to the expansion step (ii).

13. 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, d. Outlet for absorbent stream AS1, e. Inlet for absorbent stream AS2 and A regeneration tower having, c) Heat transfer system HP1, a. Heat exchanger HE1, A first inlet for heat stream HS1 and an outlet for heat stream HS2, A second inlet for the heat transfer medium stream HTMS1, which is essentially composed of the heat transfer material HTM, and a second outlet for the heat transfer medium stream HTMS2a. A heat exchanger HE1 has, b. Means for expanding the heat transfer material stream HTMS2a to obtain a gaseous heat transfer material stream HTMS2b(g) having a lower pressure compared to the heat transfer material stream HTMS2a, c. 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 HTMS2b(g), and the outlet of the last compressor in the series has an outlet for a compressed heat transfer medium stream HTMS3. d. Heat exchanger HE-R, A first inlet for the heat transfer medium stream HTMS3 and an outlet for the heat transfer medium stream HTMS4, A second inlet for absorbent stream AS1 and a second outlet for absorbent stream AS2 Heat exchanger HE-R and The heat transfer system HP1 is equipped with A device equipped with the following features.

14. The apparatus according to claim 13, wherein the means for expanding the heat transfer material stream HTMS2a comprises an expansion valve and an expansion container.

15. The apparatus according to claim 13 or 14, further comprising one or more additional inlets for a heat transfer material HTM after the one or more compressors.

16. Use of the apparatus according to claim 13 for transferring thermal energy from the heat stream HS1 to the regeneration step c) in the process according to claim 1.

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