Process and device for separating an azeotropic mixture

Abstract

A process for separating an azeotropic mixture comprising exactly one distillation unit is proposed, wherein the azeotropic mixture comprises a first component and a second component, wherein the first and the second component form a first positive azeotrope, wherein the first positive azeotrope is heterogeneous or homogeneous, wherein the distillation unit comprises a vertical distillation column, a first inlet for receiving a first feed comprising the first component and the second component, a first outlet for discharging a first product, a second outlet for discharging a second product, and a third outlet for discharging the azeotropic mixture, wherein the distillation column further comprises an essentially vertically arranged, impermeable division wall arranged within the distillation column, characterized in that the division wall is arranged at and connected to the bottom of the distillation column such that it provides three sections within the distillation column, wherein a first section and a second section are arranged horizontally adjacent to each other and divided by the division wall, wherein a third section is located vertically above the first and the second section and above the division wall. The invention additionally proposes a device for separating an azeotropic mixture comprising exactly one distillation unit.

Description

[0001] Process and device for separating an azeotropic mixture Sulzer Management AG, CH-8401 Winterthur (Schweiz) P1865

[0002] The invention relates to a process and device for separating an azeotropic mixture comprising exactly one distillation unit.

[0003] Separating azeotropic mixtures is one of the challenging tasks in chemical engineering, as azeotropic mixtures comprise two or more components that boil at constant temperature and retain the same composition in both liquid and vapor phases under a given pressure.

[0004] Therefore, an azeotropic mixture cannot be separated into its two or more components by simple distillation or rectification. Each azeotropic mixture, often also called azeotrope, has a characteristic boiling point, which is either lower than the boiling point temperatures of any of its constituents, typically denoted as positive azeotrope, or higher than the boiling point of any of its constituents, typically denoted as negative azeotrope. Further, an azeotrope can either be homogeneous, wherein the components of the mixture are miscible, or heterogeneous, wherein the components of the mixture are immiscible.

[0005] Overcoming the challenge presented by the separation of azeotropic mixtures requires advanced techniques that exploit differences in physical and chemical properties of the components under modified conditions, as outlined below.

[0006] A first well-known method for separating an azeotropic mixture is pressure-swing distillation, which takes advantage of the fact that many azeotropes change composition or cease to exist at different pressures. By conducting distillation at two different pressures in two different unit operations separating an azeotrope, may be possible without addition of any other agents. However, this first method, often used for isopropanol-water separation, typically suffers from high energy consumption and capital costs for pressure-resistant equipment.A second method comprises modification of the azeotrope during azeotropic distillation, wherein an entrainer, i.e. a third component, is added to the azeotropic mixture to alter the volatility of one or more components, thus breaking the azeotropic behavior. The entrainer forms a secondary azeotrope with one component, allowing its separation from the mixture. Afterwards, the entrainer is recycled using a second distillation unit. While this second method, often used e.g. for separating ethanol-water using benzene as entrainer, is very effective for positive azeotropes, precise selection of the entrainer is necessary for it to be easily recoverable and non-reactive. Further, recovery of the entrainer typically requires a second separation step, oftentimes another azeotropic distillation.

[0007] Third, extractive distillation for separating an azeotropic mixture involves adding a high-boiling, essentially non-volatile solvent that selectively interacts with one component of the azeotropic mixture to alter its relative volatility. In contrast to using an entrainer, this solvent should not form a secondary azeotrope with any of the components and can be recovered after the process, yet often only in energy-intensive external processes. As an example, ethylene glycol is often used as solvent to separate an ethanol-water azeotrope.

[0008] Fourth, membranes can be used to selectively separate components based on their respective molecular size, polarity, or other properties. One of the main membrane separation techniques is pervaporation, which involves the selective permeation of one component through a membrane, leaving the other behind, rendering particularly effective for separating azeotropes like ethanol-water mixtures. While in contrast to the first three techniques, membrane separation is generally a relatively energy-efficient and environmentally friendly process, it’s high cost and sensitivity to fouling present significant hurdles for many applications.

[0009] In addition to the above mentioned four techniques, a number of specialty processes are described in the literature, comprising the use of adsorbents, liquid-liquid extraction, reactive distillation, or cryogenic separation, which all present specific advantages for niche applications, yet suffer from a multitude of issues, often linked to poor performance, high detrimental ecological impact, and economical hurdles, such as high operating or capital cost.

[0010] Nevertheless, despite great efforts towards sustainable, energy- and cost-efficient azeotrope separation techniques, novel processes are in great demand to address the limitations of traditional methods. Particularly, the emergence of complex mixtures in modern chemical, pharmaceutical, and biofuel industries requires more precise and adaptable separation approaches.Dividing wall columns (DWCs), often also called partition wall columns (PWCs) represent a revolutionary advancement in chemical process engineering to enhance the integration of previously separate distillation unit operations into a combined distillation column and thus enable greater operational efficiency, by employing a physical barrier within a distillation column. Typically, a dividing wall column includes at least one vertical partition or dividing wall inside the distillation column, wherein the diving wall(s) split(s) the column into a number of sections, often two or four sections. This configuration enables a single column to achieve what traditionally required multiple columns operating in sequence. Even though more complex to engineer, dividing wall columns offer numerous advantages by combining multiple distillation steps into a single column, significantly reducing energy consumption by minimizing reboiler and condenser duties, enabling separation of ternary mixtures, and providing enhanced product purity in a compact design through process intensification. The advantages of DWCs are particularly prominent, when a high number of theoretical separation stages is needed, for example in petrochemicals separation, e.g., for naphtha cuts or aromatics separation, in biofuels for refining ethanol mixtures, or in specialty chemicals for complex separations requiring high purity.

[0011] However, while dividing wall columns excel in separating mixtures with distinct boiling points by integrating multiple distillation steps within a single unit, azeotropes have constant boiling points and retain the same composition in liquid and vapor phases, which complicates their separation, which conventionally relies on the use of multiple distillation units and entrainer addition, pressure swings, or extractive distillation to break the azeotropic behavior. Further, if entrainers are used for azeotropic separation, they often require additional separation and recycling steps, which leads to increased investment and operational cost. This complexity is illustrated by the available state-of-the-art technologies, wherein combinations of dividing wall columns and additional columns are used, as for example in LIS2015 / 0166445 A1 to dehydrate aqueous dilutions of compounds forming an azeotrope with water, to perform extractive distillation with use of a solvent, essentially separating the azeotrope at hand. While effective, these setups still demand significant capital and operational investments, require a large spatial footprint, and consume substantial amounts of energy.Starting from this state of the art, it is therefore an object of the invention to propose a process and device for separating azeotropic mixtures which enables simultaneous separation of multiple mixtures by streamlining the entire separation process into a singlecolumn system, thereby improving energy efficiency, reducing spatial footprint, and optimizing operational costs.

[0012] The subject matter of the invention satisfying this object is characterized by the features of the independent claims.

[0013] Thus, according to the invention, a process for separating an azeotropic mixture comprising exactly one distillation unit is proposed, wherein the azeotropic mixture comprises a first component and a second component, wherein the first and the second component form a first positive azeotrope, wherein the first positive azeotrope is heterogeneous or homogeneous, wherein the distillation unit comprises a vertical distillation column, a first inlet for receiving a first feed comprising the first component and the second component, a first outlet for discharging a first product, a second outlet for discharging a second product, and a third outlet for discharging the azeotropic mixture, wherein the distillation column further comprises an essentially vertically arranged, impermeable division wall arranged within the distillation column, wherein the division wall is arranged at and connected to the bottom of the distillation column such that it provides three sections within the distillation column, wherein a first section and a second section are arranged horizontally adjacent to each other and divided by the division wall, wherein a third section is located vertically above the first and the second section and above the division wall.

[0014] As in such a process, the distillation column in the exactly one distillation unit is divided into three sections with a division wall, multiple separation zones are created within a single structural unit. The three sections within the single distillation unit column can be optimized to handle distinct phases of the separation process, such as initial rectification, azeotrope breaking, and final purification, therefore eliminating the need for separate distillation columns, and offering a compact and energy-efficient alternative to traditional setups. It should be noted that the division wall within the column effectively segregates the internal space into independent zones while maintaining overall continuity within the system. Each section can operate under specific conditions tailored to the unique requirements of azeotropic separation. One example of operation could be that the first section handles the feed mixture and initiates separation by concentrating one of the components, the second section focuses on breaking the azeotropic bond, and the third section purifies the final components, achieving high-purity separation of the individual substances, yet it goeswithout saying, that the individual tasks and operation modes of each section are interchangeable and depend on the overall separation target to be achieved. One of the most significant advantages of the proposed dividing wall column design is its potential for energy savings. In conventional multi-column systems, energy losses occur as the mixture is transferred between columns. The single-column system eliminates these inter-column losses by confining all operations to one structure. Additionally, the apparatus allows for precise thermal and mass transfer control, further optimizing energy use and the. the compact nature of the apparatus drastically reduces the spatial footprint of the single distillation unit. This makes it particularly valuable in industries where space is a critical constraint, such as pharmaceutical manufacturing, petrochemicals, and fine chemicals production.

[0015] In a preferred embodiment, the distillation column comprises a second inlet for receiving a second feed, wherein a decanter is in fluid communication with the third outlet for receiving the azeotropic mixture from the third outlet, wherein the decanter provides a third feed, which is optionally mixed with or replaces the second feed, wherein third feed is supplied to the second inlet of the distillation column. This configuration enables a further increase of operational efficiency as it provides separation of components by gravitational forces before re-entering the distillation column. It must be noted, that in other embodiments the first inlet and the second inlet can be mixed outside of the column, entering the column in the same place, or entering the column in different places but feeding to the same section.

[0016] Further, one preferred configuration is that a fourth feed, comprising a third component, is supplied to the decanter, wherein the fourth feed is configured as an entrainer and for forming a second heterogeneous positive azeotrope. This is particularly advantageous if the first azeotrope is homogeneous.

[0017] A mixing zone is arranged on one side vertically above the first section and the second section and on the other side arranged vertically below the third section, wherein the first inlet of the distillation column is arranged such that the first feed is supplied to the mixing zone, wherein the division wall prevents an entering of any liquid component of the first feed into the second section. This configuration provides space for arranging inlets for supplying liquid feeds to the top of the first and second section, and enables vapors from the first and second section to rise to the third sections, while distributing liquids from the third section to either the first and second section with specific ratios, or the first section only, or the second section only.Another preferred configuration is that the second inlet of the distillation column is arranged such that the third feed is supplied to the mixing zone, wherein the division wall prevents an entering of any liquid component of the third feed into the first section.

[0018] Further, a preferred embodiment is that the distillation unit comprises for each of the first section and the second section a separate re-boiling device, which enhances the efficiency of the separation process as each re-boiling device and each of the first and second section can be specifically adapted to the desired components treated in each section.

[0019] Another advantageous configuration is that all liquid components accumulating at the bottom of the third section are prevented from entering the second section. To this end, liquid collecting devices, such as for example chimney trays can be arranged at the bottom of the third section, enabling all gaseous components to move freely from the first or the second section through the mixing section into the third section, while collecting all liquid components from the third section at the top of the mixing section. These collected liquid components are then routed through the mixing section with or without contact to the gases in the mixing section, for example by means of appropriate tubing, for finally being directed to the top of the first section. By extending the dividing wall into the mixing section, further prevention of spillover can be realized.

[0020] In a further embodiment the third section of the distillation column comprises a third inlet and the decanter provides a fifth feed to the third inlet, which enables direct liquid recycling of components accumulating in the decanter for example to the top section of the section C. Further, an advantageous configuration is that the third section comprises a fourth outlet for discharging of liquids collecting at the bottom of the third section, which enables an optional side draw.

[0021] Further, in a preferred embodiment of the process according to the invention, the first section (A) and the second section (B) each comprise either a structured column packing or a random column packing, and the third section (C) comprises a random column packing, which enhances the heat and mass transfer in each section.

[0022] In other embodiments, the efficiency of the heat and mass transfer can be further improved by arranging advanced liquid distributors above or within the packing to mitigate layer separation which might occur inside the respective sections A, B, or C.

[0023] The selection of column packings for the first section A, the second section B, and the third section C plays a crucial role during operation of the dividing wall column and the packing material, structure, and type need to be carefully adapted to the needs of the azeotrope to be separated. For example, particularly suitable structured column packings comprise SulzerMellapakEvo, Mellapak, Mellapak Plus, MellapakCC, AYPIus, BX, Mellacarbon, Mellagrid, Nuttergrid, or F-Grid, as well as other standard or custom designed structured column packings. As further example, particularly suitable random column packings comprise Sulzer NeXRing, and conventional random column packings such as Sulzer Nutter Ring, l-Ring, C-Ring, P-Ring, Plastic P-Ring, as well as other standard or custom designed random column packings.

[0024] Further, a chimney tray is arranged vertically above the mixing section at the bottom end of the third section, which enables enhanced distribution of gases over the cross section of the third section, while reliably collecting liquids from the third section for potential removal from the process and preventing spillover.

[0025] In addition, according to the invention, a device for separating an azeotropic mixture comprising exactly one distillation unit is proposed, wherein the azeotropic mixture comprises a first component and a second component, wherein the first and the second component form a first positive azeotrope, wherein the first positive azeotrope is heterogeneous or homogeneous, wherein the distillation unit comprises a vertical distillation column, a first inlet for receiving a first feed comprising the first component and the second component, a first outlet for discharging a first product, a second outlet for discharging a second product, and a third outlet for discharging the azeotropic mixture, wherein the distillation column further comprises an essentially vertically arranged, impermeable division wall arranged within the distillation column, wherein the division wall is arranged at and connected to the bottom of the distillation column such that it provides three sections within the distillation column, wherein a first section and a second section are arranged horizontally adjacent to each other and divided by the division wall, wherein a third section is located vertically above the first and the second section and above the division wall.

[0026] A further preferred configuration is that the distillation column comprises a second inlet for receiving a second feed, wherein a decanter is in fluid communication with the third outlet for receiving the azeotropic mixture from the third outlet, wherein the decanter provides a third feed, which is optionally mixed with or replaces the second feed, wherein third feed is supplied to the second inlet of the distillation column.

[0027] Further advantageous measures and embodiments of the invention will become apparent from the dependent claims.The invention will be explained in more detail - both regarding the process and the device -hereinafter with reference to embodiments of the invention and with reference to the drawings.In the drawings is shown:

[0028] Fig. 1 : a schematic process diagram of a first embodiment of a process for separating an azeotropic mixture according to the invention, including a schematic drawing of a first embodiment of a distillation unit,

[0029] Fig. 2 a schematic process diagram of a second embodiment of a process for separating an azeotropic mixture according to the invention, including a schematic drawing of a second embodiment of a distillation unit.

[0030] A first embodiment of a process for separating an azeotropic mixture comprising exactly one distillation according to the invention is shown in Fig. 1, wherein the distillation unit is denoted by the reference numeral 10, herein shown as a vertical distillation column 10’. A first inlet 11 for receiving a first feed 11’ comprising a first component and a second component is arranged to supply the first feed 1 T to the top of a first section A. A first outlet 12 for discharging a first product 12’ is arranged at the bottom of the first section A. A second outlet 13 for discharging a second product 13’ is arranged at the bottom of a second section B, and a third outlet 14 for discharging the azeotropic mixture is arranged at the top of a third section C. The distillation column 10’ further comprises a division wall 15, wherein the division wall 15 is arranged at and connected to the bottom of the distillation column 10’ such that it provides the three sections A, B, and C within the distillation column 10’. Further, the distillation column 10’ comprises a second inlet 20 for receiving a second feed 20’, wherein the first inlet 11 is arranged to supply the first feed 1 T to the top of the first section A, and the second inlet 20 is arranged to supply the second feed 20’ to the top of the second section B. It must be noted that in other embodiments, this order could be reversed, or both inlets supply both feeds to the top of the same section. In the first embodiment, a decanter 21 is in fluid communication with the third outlet 14 for receiving the azeotropic mixture from the third outlet 14, while the decanter provides a third feed 22, which is mixed with the second feed 20’, wherein the third feed 22 is supplied to the second inlet 20. Herein, the first and the second inlet 11, 20 are arranged within a mixing zone D, which is arranged on one side vertically above the first section A and the second section B and on the other side arranged vertically below the third section C. As described above, in the first embodiment, the first inlet 11 is arranged such that the first feed 1 T is supplied to the mixing zone D in a way that the first feed 1 T is supplied to the top of the first section A, and the division wall 15 prevents an entering of any liquid component of the first feed 1 T into the second section B. Vice versa, the second inlet 20 of the distillation column 10’ is arranged such that the thirdfeed 22 is supplied to the mixing zone D and the division wall 15 prevents an entering of any liquid component of the third feed 22 into the first section A.

[0031] Further, a fourth feed 30 is configured to supply an entrainer to a decanter 21, and the third section C of the distillation column 10’ comprises a third inlet 80 to which the decanter 21 provides a fifth feed 80’. In addition, the third section C comprises a fourth outlet 90 for discharging of liquids 90’ collecting in a chimney tray 110 at the bottom of the third section C. Furthermore, in the first embodiment, the distillation unit 10 comprises two separate reboiling devices 60 and 61, one for each of the first section A and second section B. In this embodiment, the first section A and the second section B further each comprise a structured column packing, whereas and the third section C comprises a random column packing. In other embodiments, the first section A and the first section B each can either comprise structured column packings or random column packings.

[0032] The first embodiment could for example be used for separating an azeotropic mixture of amyl alcohol and water.

[0033] Amyl alcohol is commonly produced by the hydration of an alkene in the presence of an acidic catalyst. This process results in the formation of a two-phase mixture due to the hydrophobic nature of amyl alcohol, which is only sparingly soluble in water. Therefore, amyl alcohol and water form a heterogeneous azeotrope, boiling at around 95.5 °C under atmospheric pressure, with an amyl alcohol concentration of approximately 71 mass %. However, alkene residues from the hydration step might be present in the azeotrope mixture. To separate these components, a multi-step distillation process is employed within the single distillation unit 10, wherein the azeotropic mixture is used as feed 1T, feed 12’ represents the pure product amyl alcohol, feed 13’ and the discharge 90’ represent pure water, feed 22 remains unused and could be used for discharging (see Fig. 1 - dashed line from feed 22) of aqueous layer from decanter 21, while feed 80 is a partial recycle of alkenes an can serve for discharging of alkenes (see Fig. 2 - dashed line from feed 80). The entrainer feed 30 remains unused. During the process, a first step involves separating the water-rich phase from the amyl alcohol-rich phase. The water-rich phase contains some dissolved amyl alcohol, which is further distilled to recover the alcohol. The amyl alcohol-rich phase, which contains minimal water, is then purified by azeotropic or extractive distillation to obtain pure amyl alcohol. This process efficiently separates the two components in a single distillation unit, taking advantage of the heterogeneous azeotrope formation and the differences in their volatilities.A second embodiment of a process for separating an azeotropic mixture comprising exactly one distillation according to the invention is shown in Fig. 2, wherein the distillation unit is again denoted by the reference numeral 10, herein shown as a vertical distillation column 10’. The first inlet 11 for receiving the first feed 1 T comprising the first component and the second component is arranged to supply the first fee 1 T to the top of the first section A . The first outlet 12 for discharging a first product 12’ is arranged at the bottom of the first section. The second outlet 13 for discharging a second product 13’ is arranged at the bottom of the second section B, and the third outlet 14 for discharging the azeotropic mixture is arranged at the top of the third section C. The distillation column 10’ further comprises the division wall 15, wherein the division wall 15 is arranged at and connected to the bottom of the distillation column 10’ such that it provides the three sections A, B, and C within the distillation column 10’. Further, the distillation column 10’ comprises the second inlet 20 for receiving a second feed 20’, wherein the first inlet 11 is arranged to supply the first feed 1 T to the top of the first section A, and the second inlet 20 is arranged to supply the second feed 20’ to the top of the second section B. It must be noted that in other embodiments, this order could be reversed, or both inlets supply both feeds to the top of the same section. In the second embodiment, the decanter 21 is in fluid communication with the third outlet 14 for receiving the azeotropic mixture from the third outlet 14, while the decanter 21 provides the third feed 22, which is mixed with the second feed 20’, wherein the third feed 22 is supplied to the second inlet 20. Herein, the first and the second inlet 11, 20 are arranged within the mixing zone D, which is arranged on one side vertically above the first section A and the second section B and on the other side arranged vertically below the third section C. In the second embodiment, the first inlet 1 land the second inlet 20 are arranged such that the first feed 1 T and the second feed 20’ are supplied to the mixing zone D in a way that the first feed 1 T and the second feed 20’ are supplied to the top of the second section B, and the division wall 15 prevents an entering of any liquid component of the first feed 1 T and the second feed 20’ into the first section A.

[0034] Further, the fourth feed 30 is configured to supply an entrainer to the decanter 21 , and the third section C of the distillation column 10’ comprises a third inlet 80 to which the decanter 21 provides a fifth feed 80’. In addition, the third section C comprises the chimney tray 110 at the bottom of the third section C.

[0035] Furthermore, in the second embodiment, the distillation unit 10 comprises the two separate re-boiling devices 60 and 61, one for each of the first section A and second section B. In thissecond embodiment, the first section A and the second section B further each comprise a structured column packing, whereas and the third section C comprises a random column packing. In other embodiments, the first section A and the first section B each can either comprise structured column packings or random column packings.

[0036] The second embodiment could for example be used for separating an azeotropic mixture of isopropanol and water.

[0037] Isopropanol is used in a variety of applications, and soluble in water, forming an azeotrope at a temperature of 80.3-80.4 °C. This azeotrope is a homogeneous minimum boiling azeotrope, with an I PA concentration of 87.4-87.7 mass % under atmospheric conditions. Due to the close boiling points of the components, conventional distillation cannot separate this azeotrope effectively. To separate these components, a multi-step distillation process is employed within the single distillation unit 10, wherein the azeotropic mixture is used as feed 1T, feed 12’ represents the pure product isopropanol, feed 13’ represents pure water, feed 30 comprises an entrainer and feed 80 is a recycle of organic compounds. To achieve separation, a multi-step distillation process is used in the single distillation column 10’. First, the ternary azeotrope of isopropanol, water, and cyclohexane as entrainer (boiling temperature of 64.1 °C) is removed, followed by the binary azeotrope of isopropanol and cyclohexane (boiling temperature of 69.3 °C), and finally, pure isopropanol is obtained.

Claims

CLAIMS1. A process for separating an azeotropic mixture comprising exactly one distillation unit (10), wherein the azeotropic mixture comprises a first component and a second component, wherein the first and the second component form a first positive azeotrope, wherein the first positive azeotrope is heterogeneous or homogeneous, wherein the distillation unit (10) comprises a vertical distillation column (10’), a first inlet (11) for receiving a first feed (1T) comprising the first component and the second component, a first outlet (12) for discharging a first product (12’), a second outlet (13) for discharging a second product (13’), and a third outlet (14) for discharging the azeotropic mixture, wherein the distillation column (10’) further comprises an essentially vertically arranged, impermeable division wall (15) arranged within the distillation column, wherein the division wall (15) is arranged at and connected to the bottom of the distillation column (10’) such that it provides three sections within the distillation column (10’), wherein a first section (A) and a second section (B) are arranged horizontally adjacent to each other and divided by the division wall (15), wherein a third section (C) is located vertically above the first and the second section (A, B) and above the division wall (15), and wherein a mixing zone (D) is arranged on one side vertically above the first section (A) and the second section (B) and on the other side arranged vertically below the third section (C), wherein the first inlet (11) of the distillation column (10’) is arranged such that the first feed (11’) is supplied to the mixing zone (D), wherein the division wall (15) prevents an entering of any liquid component of the first feed (11’) into the second section (B), and a chimney tray (110) is arranged vertically above the mixing section (D) at the bottom end of the third section (C).

2. A process in accordance with claim 1 , wherein the distillation column (10’) comprises a second inlet (20) for receiving a second feed (20’), wherein a decanter (21) is in fluid communication with the third outlet (14) for receiving the azeotropic mixture from the third outlet (14), wherein the decanter provides a third feed (22), which is optionally mixed with or replaces the second feed (20’), wherein third feed (22) is supplied to the second inlet (20) of the distillation column (10’).

3. A process in accordance with claim 2, wherein a fourth feed (30), comprising a third component, is supplied to the decanter (21), wherein the fourth feed (30) is configured as an entrainer and for forming a second heterogeneous positive azeotrope.

4. A process in accordance with claim 2, wherein the second inlet (20) of the distillation column (10’) is arranged such that the third feed (22) is supplied to the mixing zone (D), wherein the division wall (15) prevents an entering of any liquid component of the third feed (22) into the first section (A).

5. A process in accordance with anyone of the preceding claims, wherein the distillation unit (10) comprises for each of the first section (A) and the second section (B) a separate re-boiling device (60, 61).

6. A process in accordance with anyone of the preceding claims, wherein all liquid components accumulating at the bottom of the third section (C) are prevented from entering the second section (B) by the chimney tray (110).

7. A process in accordance with anyone of the claims 2-6, wherein the third section (C) of the distillation column (10’) comprises a third inlet (80) and the decanter (21) provides a fifth feed (80’) to the third inlet (80).

8. A process in accordance with anyone of the preceding claims, wherein the third section (C) comprises a fourth outlet (90) for discharging of liquids (90’) collecting at the bottom of the third section (C).

9. A process in accordance with anyone of the preceding claims, wherein the first section (A) and the second section (B) each comprise either a structured column packing or a random column packing, and the third section (C) comprises a random column packing.

10. A device for separating an azeotropic mixture comprising exactly one distillation unit (10), wherein the azeotropic mixture comprises a first component and a second component, wherein the first and the second component form a first positive azeotrope, wherein the first positive azeotrope is heterogeneous or homogeneous, wherein the distillation unit (10) comprises a vertical distillation column (10’), a first inlet (11) for receiving a first feed (1T) comprising the firstcomponent and the second component, a first outlet (12) for discharging a first product (12’), a second outlet (13) for discharging a second product (13’), and a third outlet (14) for discharging the azeotropic mixture, wherein the distillation column (10’) further comprises an essentially vertically arranged, impermeable division wall (15) arranged within the distillation column, wherein the division wall (15) is arranged at and connected to the bottom of the distillation column (10’) such that it provides three sections within the distillation column (10’), wherein a first section (A) and a second section (B) are arranged horizontally adjacent to each other and divided by the division wall (15), wherein a third section (C) is located vertically above the first and the second section (A, B) and above the division wall (15), and wherein a mixing zone (D) is arranged on one side vertically above the first section (A) and the second section (B) and on the other side arranged vertically below the third section (C), wherein the first inlet (11) of the distillation column (10’) is arranged such that the first feed (11’) can be supplied to the mixing zone (D), wherein the division wall (15) can prevent an entering of any liquid component of the first feed (11’) into the second section (B), and a chimney tray (110) is arranged vertically above the mixing section (D) at the bottom end of the third section (C).

11. A device in accordance with claim 10, wherein the distillation column (10’) comprises a second inlet (20) for receiving a second feed (20’), wherein a decanter (21) is in fluid communication with the third outlet (14) for receiving the azeotropic mixture from the third outlet (14), wherein the decanter provides a third feed (22), which is optionally mixed with or replaces the second feed (20’), wherein third feed (22) is supplied to the second inlet (20) of the distillation column (10’).

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