Method and system for reusing distillation energy in plants, including CO2 uptake by carbon capture.

Abstract

The present invention relates to a method, system and plant for energy consumption reduction, preferably a green methanol plant. The present invention provides a reduction in the overall energy consumption of the green plant, i.e. recycling of distillation energy to the stabilizer tower and recycling of carbon capture unit to the CO2 reboiler, thereby reducing the electricity intake to the heater / boiler or reducing fuel consumption in steam generation.

Description

Technical Field

[0001] Technical Field of the Invention The present invention relates to a method, a system and a plant for reducing energy consumption, preferably a green methanol plant.

Background Art

[0002] Background of the Invention The product of a methanol synthesis plant, generally defined as crude methanol, is an aqueous methanol solution containing by-products of the synthesis reaction, including ethanol, ketones, higher alcohols, and several dissolved gases mainly containing H2, CO, CO2, N2, CH4. It is known.

[0003] Known distillation processes are substantially based on one or more distillation columns. Typically, at least one column can separate the light product (light product) (e.g., gas) recovered at the top of the column from methanol, and at least one column can separate the heavy product (heavy product) (e.g., aqueous solution) recovered at the bottom of the column from methanol.

[0004] A specific method widely used for distillation of methanol, etc., involves two columns operating at atmospheric pressure or near atmospheric pressure. More specifically, it is a method using a pretreatment column known as a stabilization column or a pre-run column and a second distillation column. The first column has the purpose of separating the more volatile components contained in the crude methanol substantially. There, the crude methanol is received and the light components are separated at the top, and the aqueous solution is separated at the bottom. The second column, known as the enrichment column, performs the actual distillation, obtaining (i) purified methanol at the top, (ii) a mainly aqueous stream ("bottom water") at the bottom, and (iii) a side stream known as "fusel oil" containing mainly water, residual methanol (about 1% of the total), and most of the by-products of the synthesis reaction. Fusel oil has a certain amount of heat and is usually used as a fuel or feed for syngas production.

[0005] Each column includes a reboiler that heats the bottom of the column and maintains a heat input to the distillation method. Each column also includes a condenser that condenses the top product and recirculates it (at least partially) back into the column. Heat is supplied to the concentration (or distillation) column by steam or process gas (if available) at an appropriate heat level. The cooling medium for the condenser is typically water or air. While the above configuration with two columns is simple as a plant (e.g., a methanol distillation plant), it has a major drawback: it consumes a considerable amount of energy due to the heat supplied to the bottom reboiler and the cooling water and / or power consumption for the top condenser. Furthermore, the relatively large diameter of the columns relative to the production capacity increases the cost of the plant.

[0006] The standard method shown in Figure 1 is based on a low-pressure enrichment column, where the generated methanol vapor is condensed by a water cooler. In large-scale plants, the enrichment column is divided into two or three distillation columns with staggered pressure levels, and the overhead duty is reused as the reboiler duty of the next column. Typically, the heat required for methanol distillation and CO2 stripping is supplied, primarily or entirely, by vapor. [Overview of the project] [Problems that the invention aims to solve]

[0007] However, in methanol production, there is a need to pursue more sustainable methods that enable energy reuse and / or conservation.

[0008] The combustion of fossil fuels generates more than 13 gigatons of CO2 annually. Concerns about the impact of CO2 on climate change and ocean acidification have led governments and industries to investigate the feasibility of technologies to capture the resulting CO2 entering the carbon cycle. However, existing power plants require the separation of CO2 from the flue gas using scrubbers after combustion. In such systems, fossil fuels are burned with air, and CO2 is selectively removed from a mixed gas containing N2, H2O, O2, trace amounts of sulfur, nitrogen, and metallic impurities. While the exact separation conditions depend on the fuel and technology, CO2 generally exists at low concentrations (4-15% v / v) in a mixed gas near atmospheric pressure at a temperature of approximately -60°C. Carbon scavenging sorbents can be regenerated using temperature, pressure, or vacuum, recovered for CO2 sequestration or utilization, and the sorbents can be reused.

[0009] The biggest obstacle to carbon capture is the large amount of electricity required. Without policy and tax incentives, electricity production from such power plants would not be competitive with other energy sources. The biggest operating cost of a power plant associated with carbon capture is the reduction in power generation, because the energy in the form of steam is diverted from generating electricity in the turbine to regenerating the sorbent.[6] Therefore, minimizing the amount of energy required to regenerate the sorbent is the primary goal behind many carbon capture studies. [Means for solving the problem]

[0010] The present invention (Figure 2) follows a similar principle to the standard method described above, but operates the enrichment tower at a higher pressure, preferably about 2 to 10 barg, and reuses the overhead duty. By operating the tower at high pressure, the boiling point of the liquid at each position in the tower is raised. The target temperature for the boiling liquid is between about 110 and 190°C. The higher temperature is required in the heat exchanger D, such as a reboiler (take-in steam), but the temperature for condensation in the overhead heat exchanger C, such as a reboiler, is also raised, so that the heat can be used elsewhere, such as for CO2 reboiler duty or district heating.

[0011] Because green plants are small in scale, this type of plant typically has only one enrichment tower, and the duty cycle cannot be reused in a second enrichment tower. Instead, the overhead duty cycle is reused, at least partially, in a CO2 reboiler, reusing such energy and minimizing waste. [Brief explanation of the drawing]

[0012] drawing Figure 1 shows a standard method for methanol production in a green methanol plant with CO2 stripping. Figure 2 shows a preferred embodiment of the present invention for methanol production in a green methanol plant with CO2 stripping.

[0013] Reference number (1) High-temperature overhead flow containing methanol vapor (2) Heat supplied from heat exchanger C to CO2 stripping unit A (3) Steam flow [Best Mode for Carrying Out the Invention]

[0014] definition "Atmospheric pressure" means 1,01325 bar, or approximately 1 bar. Carbon capture refers to a method of recovering carbon dioxide from a flow (typically flue gas, but also possible from pressurized process gas). This method consists of an absorber in which a liquid sorbent comes into contact with the gas and selectively absorbs CO2. The sorbent loaded with CO2 is sent to a stripper, where heat is used to remove the encoded CO2, and the concentrated CO2 is discharged from the stripper.

[0015] A carbon dioxide sorbent is an sorbent that can absorb CO2. A carbon dioxide sorbent can be a physical material, such as a porous material, or a chemical material, such as an amine aqueous solution that forms chemical bonds.

[0016] A carbon dioxide stripping unit is a unit used to desorb captured carbon dioxide. Typically, the CO2 solution loaded into the tower is boiled to remove the captured CO2.

[0017] A chemical sorbent is an adsorbent that absorbs CO2 and forms a chemical bond between the active ingredient and the CO2.

[0018] A “concentration column,” “distillation column,” or “bottom column” refers to a column divided into a series of stages. These correspond to a cascade of equilibrium stages. The liquid flows down the column from stage to stage, coming into contact with the vapor flowing upwards. Traditionally, most columns have been constructed from a distinct set of “trays” or “plates,” so these terms are essentially interchangeable with “stages.” Each tray in a distillation column is designed to facilitate contact between the vapor and liquid on the stage. Distillation can be performed in a packed column (just as absorption can be performed in a tray column). The operating pressure of the column is usually controlled by adjusting the heat removal in a heat exchanger. The base of the column is typically used as a reservoir to hold the liquid flowing out from the bottom tray. A heat exchanger, such as a reboiler, is used to boil this liquid. The resulting vapor, “boiled up,” is returned to the bottom of the column.

[0019] Crude methanol is distilled to meet the purity standards required in the market. Crude methanol is typically a solution containing 65-95% methanol, water, and other components. Crude methanol contains low-boiling and high-boiling components (light and heavy parts). The light part L mainly contains dissolved gases (such as CO2), dimethyl ether, methyl formate, acetone, etc. The heavy part H contains higher alcohols, long-chain hydrocarbons, higher ketones, and esters of lower alcohols with formic acid, acetylic acid, and propionic acid. For example, the Grade AA specification requires a minimum methanol concentration of 99.85% by mass, and ethanol must not exceed 10 ppm by mass.

[0020] "Distillation" refers to a method of separating a liquid mixture into two or more vapors or liquids with different compositions. Distillation is an equilibrium stage operation. At each stage, the gas phase contacts the liquid phase, and mass transfers from the vapor to the liquid and from the liquid to the vapor. Components with low volatility, "heavy" or "high-boiling", concentrate in the liquid phase, while components with high volatility, "light", concentrate in the vapor phase. By using multiple stages in series and recycling, separation can be achieved. The feed to the distillation column can be a liquid, a vapor, or a mixture of liquid and vapor. It can be fed at any position in the column. Multiple streams may be fed to the system, and multiple products may be withdrawn. Distillation in a concentration column is usually carried out at the lowest possible pressure, but in the present invention, the pressure is increased to recover heat.

[0021] A green methanol plant means a plant that uses renewable hydrogen as a feedstock.

[0022] "Heat duty (heat load)" or "duty (heat load)" means the amount of heat required to move from the high-temperature side to the low-temperature side within a unit time. The equations for calculating heat duty are usually described in the following two ways: a) applicable to the sensible heat transferred, meaning that the fluid does not undergo a phase change; b) applicable to the latent heat transferred, meaning that the fluid undergoes a phase change.

[0023] "Heat exchanger" means a system used to transfer heat between two or more fluids. Heat exchangers are used in both cooling and heating processes. The fluids may be separated by a solid wall to prevent mixing, or they may be in direct contact. In particular, "heat exchanger" means a reboiler / condenser, such as a tube bundle exchanger that evaporates a solution on the shell side and condenses the distillate on the tube side (or vice versa). It is also possible to use a plate heat exchanger in which heat exchange plates are housed in a shell.

[0024] "Heavy by-products" or "sidestreams", H, means a stream that is withdrawn - typically between the feed tray and the bottom of the column - from the final concentrator column and contains recovered higher alcohols and other by-products. This is known as "fusel oil" and contains water, residual methanol (about 1% of the total), and most of the by-products of the synthesis reaction. Fusel oil has a certain calorific value and is usually used as a feed to a fuel or syngas generation unit. The sidestream of fusel oil can also be extracted from an intermediate distillation stage as appropriate.

[0025] High-pressure distillation means a distillation method that operates above the normal operating pressure. Generally, methanol distillation is carried out at low pressure to facilitate the separation of components, while high-pressure distillation is carried out, for example, at a high pressure above 2 barg.

[0026] A loaded carbon dioxide sorbent means a solution containing captured carbon dioxide.

[0027] Methanol (MeOH) synthesis gas means synthesis gas containing a mixture of components, H2, CO and CO2 (or only H2 and CO2) for MeOH synthesis.

[0028] "Overhead duty" means the heat obtained by condensing (concentrating) methanol vapor at the top of a column such as a concentrator column.

[0029] "Partial reboiler" means a reboiler that vaporizes only a part of the liquid at the base of the column. The generated vapor is returned to the column, and the liquid stream is removed as a product or as a feed to an additional column. The compositions of these three streams are different. The partial reboiler also provides an ideal separation stage. A sidestream reboiler can be used, which can withdraw liquid from a tray, heat it, and return the vapor-liquid mixture to the same tray or a similar tray.

[0030] A physical sorbent means a sorbent that absorbs CO2 without forming a chemical bond between the active component and CO2.

[0031] "Pressure," where P stands for gauge pressure, is measured in bar(g). Gauge pressure is a relative pressure relative to atmospheric pressure; pressures higher than atmospheric pressure are positive pressure, and pressures lower than atmospheric pressure are negative pressure. The difference between bar and bar(g) is the difference in the reference point considered. Pressure measurements are always performed relative to a reference point and correspond to the value obtained from the pressure measuring instrument. If the reference point for pressure measurement is a vacuum, absolute pressure is obtained and measured only in bar units. If the reference point is atmospheric pressure, the pressure is expressed in bar(g).

[0032] Crude methanol product refers to the liquid product obtained directly from the synthesis in step (d) of the method of the present invention, and is mainly methanol, but also includes water, by-products, and dissolved gases.

[0033] A "reboiler" is a heat exchanger commonly used to supply heat to the bottom of an industrial distillation column. The reboiler boils the liquid at the bottom of the column to generate steam, which is then returned to the column for distillation separation. The heat supplied to the column by the reboiler at the bottom is removed by a condenser at the top of the column. Most reboilers are shell-and-tube heat exchangers, and steam is typically used as the heat source. However, other heat transfer fluids such as high-temperature synthesis gas, petroleum, or Dowtherm™ can also be used. Fuel combustion furnaces can also be used as reboilers in some cases.

[0034] A "stabilizing column," "topping column," or "pre-run column" is used to separate more volatile components from heavier components in crude products such as crude methanol.

[0035] A "volatile component" or "volatile substance" refers to a component or substance that readily vaporizes at low temperatures. Volatility can also describe the tendency of a vapor to condense into a liquid or solid. Substances with low volatility condense more easily from vapor than substances with high volatility. Vapor pressure measures how easily a condensed phase forms vapor at a given temperature. A substance sealed in a closed container is initially in a vacuum (no air inside), and the empty space is quickly filled with vapor. After the system reaches equilibrium and no more vapor is formed, the vapor pressure can be measured. Increasing the temperature increases the amount of vapor formed, and consequently, the vapor pressure also increases. In a mixture, each substance contributes to the overall vapor pressure of the mixture, with more volatile compounds contributing more. The boiling point is the temperature at which the vapor pressure of a liquid equals the ambient pressure, causing the liquid to rapidly evaporate, or boil. It is closely related to vapor pressure but is pressure-dependent. The usual boiling point is the boiling point at atmospheric pressure, but it may also be reported at higher or lower pressures.

[0036] "Upstream" or "top flow" refers to the flow obtained from or collected from the upper levels of a tower.

[0037] explanation The present invention provides a reduction in the overall energy consumption of a green plant (reuse of distillation energy in the stabilizer column and reuse of CO2 in the carbon capture unit for the CO2 reboiler), and a reduction in the amount of electricity taken into the heater / boiler (or a reduction in fuel consumption in steam generation).

[0038] The present invention uses one or more columns for distillation, and the column with the highest pressure is connected to at least one CO2 stripping unit. The one or more columns are connected in series with a stabilization column V0 at pressure P0 and at least one distillation column V1 at pressure P1, and each column is connected to heat exchangers E0 and E1, the heat exchangers being reboilers for the column. a) E1 has an inflow heat flow outside the apparatus; d) P1>2barg It is characterized by being such.

[0039] One of the objectives of the present invention is to reduce the energy input of a green methanol plant. A standard layout consisting of an electrolytic cell, carbon capture, methanol synthesis, and methanol distillation has been developed. Both conventional carbon capture units and methanol distillation units require heat to drive CO2 stripping (e.g., the carbon capture unit) and crude methanol distillation. Normally, this heat is supplied by steam, but in a typical green methanol plant there is no surplus steam, so this steam must be generated electrically (to minimize CO2 emissions) or by burning fuel instead.

[0040] By changing to a high-pressure distillation step, the overhead duty obtained from the overhead flow (1) of the enrichment column can be used as the reboiler duty in the CO2 stripping process (e.g., in a carbon capture unit), or it can be used in a stabilization column in methanol distillation or supplied to district heating. Preferably, the operating pressure of the enrichment column is greater than or about 2 barg.

[0041] The main advantage of this invention is that it can reduce overall energy consumption, meaning that approximately the same amount of heat sent to the enrichment tower can be reused in the CO2 reboiler. [Examples]

[0042] example Example 1 Energy consumption in CO2 stripping and methanol distillation Table 1 compares the energy consumption of a conventional layout and a new invention that reuses energy from the overhead MeOH vapor of the concentration column in a CO2 stripper and methanol distillation system. The total vapor intake is reduced to 61% of that of the standard solution. In this case, the reused heat is directed to the CO2 stripper reboiler, but alternatives include replacing the steam from a stabilized reboiler or using it for district heating.

[0043] [Table 1]

[0044] Therefore, by using the method, system, and plant of the present invention, the total steam consumption is significantly reduced by approximately 39% in this particular case compared to a standard solution.

[0045] Preferred Embodiment 1. (a) A step of capturing carbon dioxide with a carbon dioxide sorbent to form a loaded carbon dioxide sorbent; (b) Step of passing the loaded carbon dioxide sorbent through the carbon dioxide stripping unit A; (c) A step of supplying methanol synthesis gas containing hydrogen and carbon dioxide; (d) A step in which the methanol synthesis gas from step (c) is passed through methanol synthesis to form a crude methanol product; (e) A step of purifying a crude methanol product in a distillation unit B including at least one distillation column, wherein a high-temperature overhead flow (1) is obtained from the at least one distillation column, characterized in that the high-temperature overhead flow (1) supplies heat to a heat exchanger C, and at least a portion of the heat (2) is supplied to at least one carbon dioxide stripping unit A for stripping carbon dioxide from a loaded carbon dioxide sorbent, thereby condensing the flow (1) into liquid methanol; A method for producing methanol, including [a specific substance]. It is desirable to reuse all of the overhead flow (1). 100% is reused in stripping unit A, or less than 100% is reused elsewhere (e.g., as a stabilized reboiler duty or for district heating). Alternatively, 100% of the overhead heat or duty (1) is used in the CO2 stripping unit, although additional steam may also be used.

[0046] 2. The method according to Embodiment 1, wherein the methanol synthesis gas of step (c) includes hydrogen obtained from partial or whole electrolysis.

[0047] 3. The method according to Embodiment 1, wherein the methanol synthesis gas in step (c) contains hydrogen obtained from a source other than electrolysis.

[0048] 4. The method according to Embodiment 1, wherein the heat (2) supplied to at least one carbon dioxide stripping unit A is between approximately 20% and 100%, preferably between 45% and a maximum of 100%, of the energy required by the stripping unit.

[0049] 5. The method according to Embodiment 1, wherein the heat (2) supplied to the carbon dioxide stripping unit A is additionally supplied by steam (3). The flow (1) required for the carbon dioxide stripper is fixed. While the flow path (1) is supplied from distillation, the required intake vapor is reduced accordingly.

[0050] 6. The method according to Embodiment 1, wherein the carbon dioxide sorbent in step (a) is a physical or chemical sorbent.

[0051] 7. The method according to Embodiment 1, wherein the methanol synthesis gas further contains carbon monoxide.

[0052] 8. The method according to Embodiment 1, wherein the carbon dioxide in step (a) originates from flue gas and / or synthesis gas.

[0053] 9. A method according to Embodiment 1, wherein part or all of the high-temperature overhead flow (1) is supplied to district heating.

[0054] 10. A method according to Embodiment 1 or 9, wherein a portion of the high-temperature overhead flow (1) is supplied to a stabilized reboiler.

[0055] 11. The system comprises at least one CO2 stripping unit A, at least one methanol distillation unit B, and at least one overhead heat exchanger unit C fluidly connected to at least one heat exchanger unit D. The units A, B, C, and D are arranged to produce methanol according to any one of embodiments 1 to 10, wherein the crude methanol product is purified in distillation unit B, which includes at least one distillation column, and a high-temperature overhead flow (1) is obtained from the at least one distillation column. The system wherein the high-temperature overhead flow (1) supplies heat to a heat exchanger C, and at least a portion of the heat (2) is supplied to at least one carbon dioxide stripping unit A for stripping carbon dioxide from a loaded carbon dioxide sorbent, thereby condensing the flow (1) into liquid methanol.

[0056] 12. The system according to Embodiment 11, wherein units A, B, C, and D are arranged so that some or all of the overhead heat flow (1) is supplied to district heating.

[0057] 13. The system according to either embodiment 11 or 12, wherein units A, B, C, and D are arranged such that a portion of the overhead heat flow (1) is supplied to a stabilized reboiler.

[0058] 14. A plant for producing methanol according to any one of Embodiments 1 to 10, comprising a system according to any one of Embodiments 11 to 13, with CO2 uptake from carbon capture. This invention includes the following items. [Item 1] (a) A step of capturing carbon dioxide with a carbon dioxide sorbent to form a loaded carbon dioxide sorbent; (b) Step of passing the loaded carbon dioxide sorbent through the carbon dioxide stripping unit A; (c) A step of supplying methanol synthesis gas containing hydrogen and carbon dioxide; (d) A step in which the methanol synthesis gas from step (c) is passed through methanol synthesis to form a crude methanol product; (e) A step of purifying a crude methanol product in a distillation unit B including at least one distillation column, wherein a high-temperature overhead flow (1) is obtained from the at least one distillation column, characterized in that the high-temperature overhead flow (1) supplies heat to a heat exchanger C, and at least a portion of the heat (2) is supplied to at least one carbon dioxide stripping unit A for stripping carbon dioxide from a loaded carbon dioxide sorbent, thereby condensing the flow (1) into liquid methanol; A method for producing methanol, including [a specific substance]. [Item 2] The method according to item 1, wherein the methanol synthesis gas of step (c) comprises hydrogen obtained from partial or whole electrolysis. [Item 3] The method according to item 1, wherein the methanol synthesis gas in step (c) includes hydrogen obtained from a source other than electrolysis. [Item 4] The method according to item 1, wherein the heat (2) supplied to at least one carbon dioxide stripping unit A is between approximately 20% and 100%, preferably between 45% and a maximum of 100%, of the energy requirements in the stripping unit. [Item 5] The method according to item 1, wherein the heat (2) supplied to the carbon dioxide stripping unit A is additionally supplied by steam (3). [Item 6] The method according to item 1, wherein the carbon dioxide sorbent in step (a) is a physical or chemical sorbent. [Item 7] The method according to item 1, wherein the methanol synthesis gas further contains carbon monoxide. [Item 8] The method according to item 1, wherein the carbon dioxide in step (a) originates from flue gas and / or synthesis gas. [Item 9] The method according to item 1, wherein part or all of a high-temperature overhead flow (1) is supplied to district heating. [Item 10] The method according to item 1 or 9, wherein a portion of the high-temperature overhead flow (1) is supplied to a stabilized reboiler. [Item 11] at least one CO 2 The system comprises a stripping unit A, at least one methanol distillation unit B, and at least one overhead heat exchanger unit C fluidly connected to at least one heat exchanger unit D. A system for producing methanol according to any one of Examples 1 to 10, wherein units A, B, C, and D are arranged such that the crude methanol product is purified in distillation unit B, which includes at least one distillation column, and a high-temperature overhead flow (1) is obtained from the at least one distillation column, The system wherein the high-temperature overhead flow (1) supplies heat to a heat exchanger C, and at least a portion of the heat (2) is supplied to at least one carbon dioxide stripping unit A for stripping carbon dioxide from a loaded carbon dioxide sorbent, thereby condensing the flow (1) into liquid methanol. [Item 12] The system according to item 11, wherein units A, B, C, and D are arranged so that some or all of the overhead heat flow (1) is supplied to the district heating. [Item 13] The system according to item 11 or 12, wherein units A, B, C, and D are arranged such that a portion of the overhead heat flow (1) is supplied to the stabilized reboiler. [Item 14] CO from carbon capture, including a system described in any one of items 11-13 for producing methanol as described in any one of items 1-10. 2 A plant that involves intake.

Claims

1. (a) A step of capturing carbon dioxide with a carbon dioxide sorbent to form a loaded carbon dioxide sorbent; (b) The step of passing the loaded carbon dioxide sorbent through the carbon dioxide stripping unit A; (c) A step of supplying methanol synthesis gas containing hydrogen and carbon dioxide; (d) A step of passing the methanol synthesis gas from step (c) through methanol synthesis to form a crude methanol product; (e) A step of purifying a crude methanol product in a distillation unit B including at least one distillation column, and obtaining a high-temperature overhead flow (1) from the at least one distillation column by high-pressure distillation of 2 to 10 barg, wherein the high-temperature overhead flow (1) supplies heat to a heat exchanger C, and at least a portion of the heat (2) is supplied to at least one carbon dioxide stripping unit A for stripping carbon dioxide from a loaded carbon dioxide sorbent, thereby condensing the flow (1) into liquid methanol; A method for producing methanol, including [a specific substance].

2. The method according to claim 1, wherein the methanol synthesis gas of step (c) comprises hydrogen obtained from partial or whole electrolysis.

3. The method according to claim 1, wherein the methanol synthesis gas in step (c) includes hydrogen obtained from a source other than electrolysis.

4. The method according to claim 1, wherein the heat (2) supplied to at least one carbon dioxide stripping unit A is between 20% and 100% of the energy required by the stripping unit.

5. The method according to claim 1, wherein the heat (2) supplied to the carbon dioxide stripping unit A is additionally supplied by steam (3).

6. The method according to claim 1, wherein the carbon dioxide sorbent in step (a) is a physical or chemical sorbent.

7. The method according to claim 1, wherein the methanol synthesis gas further comprises carbon monoxide.

8. The method according to claim 1, wherein the carbon dioxide in step (a) is derived from flue gas and / or synthesis gas.

9. The method according to claim 1, wherein part or all of the high-temperature overhead flow (1) is supplied to district heating.

10. The method according to claim 1 or 9, wherein a portion of the high-temperature overhead flow (1) is supplied to a stabilized reboiler.

11. The method according to any one of claims 1 to 10, wherein the heat (2) supplied to at least one carbon dioxide stripping unit A is between 45% and a maximum of 100% of the energy required by the stripping unit.

12. The method according to any one of claims 1 to 11, wherein the high-temperature overhead flow (1) in step (e) has a temperature between 110 and 190°C.

13. at least one CO ２ The system comprises a stripping unit A, at least one methanol distillation unit B, and at least one overhead heat exchanger unit C fluidly connected to at least one heat exchanger unit D. A system for carrying out the method according to any one of claims 1 to 12, wherein the units A, B, C, and D are arranged such that the crude methanol product is purified in distillation unit B which includes at least one distillation column, and a high-temperature overhead flow (1) is obtained from the at least one distillation column, The system wherein the high-temperature overhead flow (1) supplies heat to a heat exchanger C, and at least a portion of the heat (2) is supplied to at least one carbon dioxide stripping unit A for stripping carbon dioxide from a loaded carbon dioxide sorbent, thereby condensing the flow (1) into liquid methanol.

14. The system according to claim 13, wherein units A, B, C, and D are arranged such that part or all of the overhead heat flow (1) is supplied to district heating.

15. The system according to claim 13 or 14, wherein units A, B, C, and D are arranged such that a portion of the overhead heat flow (1) is supplied to the stabilized reboiler.

16. A system comprising the system described in any one of claims 13 to 15, comprising CO from carbon capture. ２ A plant that involves intake.

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