TW200909408A - Azeotropic distillation with entrainer regeneration - Google Patents

Abstract

The present invention relates to a process for azeotropic distillation of a feedstock, wherein the feedstock comprises an aliphatic carboxylic acid and water, comprising conducting the azeotropic distillation in the presence of an organic entrainer to produce a liquid phase component comprising said aliphatic carboxylic acid having a reduced water content relative to the water content in the feedstock and a vapor phase component comprising the organic entrainer, an organic entrainer by-product and water, and either (i) returning a stream comprising the organic entrainer by-product to a point in the azeotropic distillation below where the feedstock is fed, wherein the organic entrainer by-product is converted to the organic entrainer or (ii) converting the organic entrainer by-product to the organic entrainer and then returning the organic entrainer to the azeotropic distillation.

Description

200909408 IX. INSTRUCTIONS OF THE INVENTION: TECHNICAL FIELD OF THE INVENTION The present invention relates to the separation of water from a liquid medium containing water and at least one organic component, more specifically, from water-containing and aliphatic carboxylic acids. Water is separated from the feed stream. This application claims priority to Provisional Application No. 60/950,426, filed on July 18, 2007. [Prior Art] f) In the preparation of terephthalic acid by, for example, liquid phase oxidation of p-xylene in an aliphatic carboxylic acid solvent such as acetic acid, water and solvent are usually used as the overhead vapor stream. It is removed from the oxidation reactor as a means of controlling the reaction temperature. The vapor stream is condensed to recover condensables, some of which can be recycled back to the oxidation reactor in a reflux mode, while the other condensables are passed to a separation process which in turn recovers the aliphatic carboxylic acid solvent having a lower water content, such as Acetic acid. A suitable separation process form comprises azeotropic distillation which is superior to fractionation due to improved ί / ie 旎刼. However, the entrainer present to complete the azeotropic distillation results in the formation of entrainer by-products such as alcohols. These by-products are - (iv) decomposed by the stripping agent under the existing conditions in the steaming tower, especially the hydrolysis. During azeotropic distillation, the by-products tend to stay on top of the steamer tower that solubilizes more water, resulting in increased energy consumption and the required column diameter. Furthermore, as the entrainer degrades and forms by-products, more entrainer must be added to the azeotropically stabilized crane tower to effect separation, which increases operating costs. There is a need in the art for a method of treating entrainer by-products. 132562.doc 200909408 allows a co-exhaustion steam tower for dehydration of aliphatic tetamine solvents to operate at low cost. SUMMARY OF THE INVENTION According to the present invention, a method of controlling and further reducing entrainer by-products generated in an azeotropic distillation column for dehydrating an aliphatic (iv) solvent has been found. In this method, the reduction of the entrainer by-product can result in the inclusion of the entrainer by the conversion of the (four) agent by-products in the co-exhaustion system or in the external containment

Health. The invention may be characterized by a method for azeotropic evaporation of a raw material, wherein the raw material comprises an aliphatic carboxylic acid and water, the method comprising: (4) performing azeotropic distillation in the presence of an organic entrainer to produce a material having a relatively high content. a liquid component of the aliphatic acid having a lower water content and a vapor phase component comprising an organic entrainer, an organic entrainer by-product, and water; and (b) comprising an organic entrainer lower than The location of the feedstock, the machine entrainer. Or the by-product stream is returned to the azeotropic distillation wherein the organic entrainer by-product is converted to (C) the organic entrainer by-product is converted to an organic entrainer; and (d) the organic entrainer is returned to the azeotropic distillation in. [Embodiment] The present invention may be characterized by a method for azeotropic distillation of a raw material, wherein the raw material comprises an aliphatic carboxylic acid and water, the method comprising: "a) performing azeotropic distillation in the presence of an organic entrainer, To produce a liquid phase component of the aliphatic acid-removing liquid phase containing the water content of the water having a lower amount of water, a organic entrainer by-product, and a vapor phase component of water; 132562.doc 200909408 (b) Returning the stream containing the organic entrainer by-product to the position in the azeotropic distillation below the feedstock feedstock' where the organic entrainer by-product is converted to the organic inflammatory tape. Another embodiment of the present invention may be characterized by a method for azeotropic distillation of a raw material, wherein the raw material comprises an aliphatic carboxylic acid and water, the method comprising: (4) azeotropic distillation in the presence of an organic entrainer to produce a liquid phase component comprising the aliphatic carboxylic acid having a lower water content than the water in the raw material and a vapor phase component comprising an organic entrainer, an organic entrainer by-product, and water;

(b) converting the organic entrainer by-product into an organic inflammatory tape; and (c) returning the organic entrainer to the azeotropic distillation. In all of the above embodiments of the present invention, the step (4) may further comprise: (1) removing the vapor phase component of the step (4) from the evaporation process; (9) condensing it to form an organic liquid phase and an aqueous liquid phase; The phase is recycled to the steaming process; (iv) the aqueous phase is stripped to recover the organic entrainer and the organic entrainer by-product and to form the first & Further, in all of the above embodiments, step () may be carried out into V package 3. (V) the second vapor phase is cooled; suspected; and (10) at least a portion of the condensate of step (7) is recycled to the stripping step. (iv). Another embodiment of the present invention may be characterized by a method of azeotropically boiling a raw material, wherein the raw material comprises an aliphatic carboxylic acid and water, and the method comprises: (4) performing a total steaming in the presence of an organic entraining agent, To produce a liquid component comprising the aliphatic repulsive acid having a lower water content than the water in the raw material and a vapor phase component comprising an organic agent, an organic entrainer by-product, and water; (b) in organic The entrainment agent, the seeding material such as the organic entrainer by-product and the water to condense and form the organic phase and the aqueous phase, the vapor phase component is condensed; 132562.doc 200909408 back to the azeotropic distillation column (C The organic phase of step (b) is topped by reflux; the stripping agent (d) purifies the aqueous phase of step (b) to remove the organic entrainer and organic by-product from the water; and (e) The organic entrainer and organic entrainer by-product are returned to a position where the azeotropic distillation is lower than the feedstock feedstock, wherein the organic entrainer by-product is converted to a machine entrainer. *'

In the above embodiment of the invention, step (b) may further comprise (丨) separating the organic phase from the aqueous phase; and the purifying operation of step (d) may comprise (1) forming an organic entrainer, an organic entrainer. The product and water stream, and (^) separate the stream into an organic phase comprising an organic entrainer and an organic entrainer by-product and an aqueous phase comprising water. Alternatively, the purification operation of step (d) may comprise (1) stripping the aqueous phase of step (b) to produce a vapor phase comprising an organic entrainer, an organic entrainer by-product, and water; (ii) in an organic entrainer, organic entrainment The by-product and water condense the vapor phase under condensation; and separate the organic entrainer, organic entrainer by-product and water into an organic phase comprising an organic entrainer and an organic entrainer by-product and water containing water phase. Another embodiment of the present invention may be characterized by a method of azeotropic distillation of a feedstock, wherein the feedstock comprises an aliphatic carboxylic acid and water. The process comprises: (a) azeotropic distillation in the presence of an organic entrainer, Producing a liquid phase component comprising the aliphatic tannic acid having a lower water content than the water in the raw material and a vapor phase component comprising an organic entrainer, an organic entrainer by-product, and water; (b) in organic entrainment The vapor phase component of step (a) is condensed by the agent, the organic entrainer by-product, and water; 132562.doc 200909408 (C) the organic entrainer, organic entrainer by-product of step (b) and The water condensate is separated into an organic phase and an aqueous phase; (d) the organic phase of step (c) is returned to the top of the azeotropic distillation column by reflux; (e) the aqueous phase of step (c) is purified to produce An organic entrainer, an organic entrainer by-product, and a stream of water; (f) separating the organic entrainer, organic entrainer by-product, and water stream of step (e) into an organic phase and an aqueous phase;

(g) returning the organic phase of step (f) to a position in the azeotropic distillation below the feed of the feedstock, wherein the organic entrainer by-product is converted to an organic entrainer. Another embodiment of the invention may be characterized by a method of azeotropic distillation of a feedstock, wherein the feedstock comprises an aliphatic citric acid and water, the process comprising: (a) azeotropic distillation in the presence of an organic entrainer, Producing a liquid phase component comprising the aliphatic carboxylic acid having a lower water content than the water in the raw material and a vapor phase component comprising an organic inflammatory tape agent, an organic entrainer by-product, and water; (b) The organic entrainer, the organic entrainer by-product, and the vapor phase component of the step (a) are condensed by condensation; (4) separating the organic entrainer, the organic entrainer by-product, and the water condensate of the step (b) into The organic phase and the aqueous phase; (d) the step of returning the organic phase of the ^ 丨, 丨 、, * 々 々 々 phase to the azeotropic distillation column by organic means (4) stripping the aqueous phase of step (4) to produce The organic entrainer entrainer by-product and the vapor phase of water; (f) condensing the vapor phase of step (e) under the strip of the organo-camp organic entrainer by-product and water by condensation 132562.doc 200909408; The organic entrainer, organic entrainer by-product and water of step (f) Condensate was separated into an organic phase and an aqueous phase; and (h) in step (g) returning the organic phase to a position lower than the azeotropic distillation of the feedstock fed, wherein the organic entrainer byproducts into organic entrainer. Another embodiment of the invention may be characterized by a method of azeotropically distilling a feedstock, wherein the feedstock comprises an aliphatic carboxylic acid and water, the process comprising: (a) azeotropic distillation in the presence of an organic entrainer, Producing a liquid phase component comprising the aliphatic acid having a lower water content than the water in the raw material and a vapor phase component comprising an organic entrainer, an organic entrainer by-product, and water; (b) in organic entrainment The component of the organic entrainer and the water are condensed to form an organic phase and an aqueous phase, and the vapor phase component is condensed; (c) the organic phase of step (b) is returned to the azeotropic distillation; (4) Purifying the aqueous phase of step (b) to remove the organic entrainer and the organic entrainer by-product from the water; (e) converting the organic entrainer by-product to the organic entrainer; and (f) returning the organic entrainer to the Azeotropic distillation. In the above embodiments of the present invention, the step may further comprise (1) separating the organic phase from the aqueous phase; and the purifying operation of the step (d) may comprise (1) forming a stream comprising an organic entrainer, an organic entrainer by-product, and water, and (ii) separating the stream into an organic phase comprising an organic entrainer and an organic entrainer by-product and an aqueous phase comprising water. Alternatively, the purification operation of the step (4) may comprise (1) stripping the aqueous phase of the step (8) to produce a vapor phase comprising an organic entrainer, an organic entrainer by-product, and water; (ii) an organic entrainer, an organic entrainer 132562. Doc 200909408 钊 product and water condense the vapor phase by condensation; and (in) separate the organic entrainer, organic entrainer by-product and water into an organic phase comprising an organic entrainer and an organic entrainer by-product and Contains the aqueous phase of water. Another embodiment of the invention may be characterized by a method of azeotropically distilling a feedstock, wherein the feedstock comprises an aliphatic carboxylic acid and water, the process comprising: (a) azeotropic distillation in the presence of an organic entrainer, Producing a liquid phase component comprising the aliphatic carboxylic acid having a lower water content than the raw material and a vapor phase component comprising an organic entrainer, an organic entrainer by-product, and water; (b) in organic entrainment The component of the step (a) is condensed by the agent, the organic stripper by-product, and the water by condensation; (c) separating the organic entrainer, the organic entrainer by-product, and the water condensate of step (b) Forming an organic phase and an aqueous phase; (4) returning the organic phase of step (C) to the top of the azeotropic distillation column by reflux; (4) purifying the aqueous phase of step (C) to produce an organic entrainer, organic entrainer a product and a water stream; (1) separating the organic entrainer, the organic entrainer by-product, and the water stream of step (4) into an organic phase and an aqueous phase; (g) converting the organic entrainer by-product in the organic phase into an organic entrainer; And (h) returning the organic entrainer to Boiling steam museum. Another embodiment of the present invention may be characterized in that the raw material comprises a total of a copper hydride, wherein the raw material comprises an aliphatic carboxylic acid and water, the method comprising: (4) azeotropic distillation in the presence of an organic entrainer, To produce a liquid phase component comprising the aliphatic carboxylic acid having a lower water content in the raw material of 132562.doc 200909408 and a vapor phase component comprising an organic sinister agent, an organic entrainer by-product, and water; (8) condensing the vapor phase component of step (a) under conditions of an organic inflammatory tape, an organic entrainer by-product, and water; (4) condensing the organic entrainer, organic entrainer by-product, and water of step (b) Separating the organic phase into an aqueous phase; (4) returning the organic phase of step (4) back to the top of the steaming tower; (4) stripping the aqueous phase of step (4) to produce an organic (tetra) agent, organic entrainer (7) condensing the vapor phase of step (e) under conditions of organic cooling agent, organic entrainer by-product and water by condensation; (g) organic entraining agent of step (1), organic phase Separation of the by-product of the agent and the water condensate into Phase and an aqueous phase; (H) by-product in the organic phase of an organic entrainer into organic entrainer; and (1) to return to the organic entrainer in the azeotropic distillation. In all embodiments, the vapor phase component comprising the organic entrainer, the organic entrainer by-product, and water in step (4) is removed from the steaming process as overhead product (eg, as overhead vapor stream from the distillation column) It is removed) and can be condensed into a liquid stream and a first-vapor stream. The first vapor stream can be passed to a second distillation column, wherein a first vapor comprising an organic entrainer, an organic entrainer by-product, and water is passed into the column and undergoes further distillation to thereby pass the organic entrainer, the organic entrainer The product and water are condensed and recovered as a liquid phase from the column, and any other impurities are left in the vapor phase. The recovered organic entrainer/organic entrainer by-product/water phase can then be phase separated for separation into an organic phase and an aqueous phase.

In all embodiments of the invention, the organic entrainer may be at least one ester selected from the group consisting of n-butyl acetate, isobutyl acetate, n-propyl acetate, isopropyl acetate, or mixtures thereof, for example Isobutyl acetate, n-propyl sulphate or isopropyl acetate; n-propyl acetate or isopropyl acetate; or n-propyl acetate. The organic entrainer can be an entrainer having a boiling point ranging from about the boiling point of isopropyl acetate to about the boiling point of n-butyl acetate (e.g., from about 88 ° C to about 126 ° C). The organic entrainer by-product may be at least one member selected from the group consisting of propanol, butanol, an alcohol corresponding to an organic vinegar entrainer, or a mixture thereof. In all embodiments of the invention, converting the organic entrainer by-product to an organic entrainer can comprise esterifying the organic entrainer by-product with an aliphatic carboxylic acid. The aliphatic carboxylic acid used for this purpose should have a relatively high concentration to promote the acetation reaction rather than the hydrolysis reaction. The aliphatic carboxylic acid is present at a concentration lower than the feed point of the distillation column. The brewing reaction can be carried out in a distillation column in which an aliphatic acid is present, or in a separate reaction vessel outside the column. The reactant aliphatic acid can be obtained fresh or derived from the bottom product. The stream to be reacted may be a relatively high concentration of entrainer by-product to promote its esterification reaction. In all embodiments of the invention, the organic phase recycled or refluxed to the azeotropic distillation column may comprise organic entrainer by-products at concentrations ranging from about !% by weight to about 15% by weight of the total weight of the composition, For example, from about 2% by weight to about 15% by weight 'or from about 1% by weight to about 10% by weight, or from about 2% by weight to about (four) amount%' or from about 2% by weight to about 8% by weight, or about 2% by weight to Approximately 6 132562.doc •14- 200909408 wt%. Suitable aromatics production methods are those which are used on the industrial scale for the production of the biochemical benzoic acid, wherein the aliphatic acid solvent is usually acetic acid. The invention can be referred to by reference to Figures i, 2, 3 Figure 4, _, Fig. 7, Fig. 8 and Fig. 9 to better understand the azeotrope steaming crane method of Gion. Fig. 4 illustrates the separation of aliphatic "with water after the = = Γ tower D1 (which can For the packed or disc type distillation column) + Ί,, 'L 3 self-oxidation reactor overhead condenser system row: water' the overhead condenser system and the production of para-xylene Words (but not limited to) 'Feed tube...The composition can be packaged: 1-/:40 wt〇/0,^99 wt%_6〇wt%,^〇^〇^aa Other feeds can be used Supply to the tower. Heat through the reboiler to the enthalpy (four). Low-boiling organic entrainer (such as acetic acid (tetra), isopropyl acetate, acetonide or acetic acid τδ|) can be supplied to the tower via the return pipe

U, and operating the column to ensure that the entrainer penetrates below the level of feed i, thereby allowing feed 1 to enter the enrichment zone in the column. a bottom product withdrawn from the bottom of column D1 via line 2 comprises, for example, an acetamidine ring to the oxidation reaction having a relatively low water content of the feed/in feed line k. For example, but not limited to, the bottom product ° = 1 Wt% _20 wt% water and 99 wt% _8 〇 wt% acetic acid. Will be at the top of the wide one. The overhead product of P is cooled in the overhead condenser system E2 relative to a suitable medium such as, but not limited to, cooling water, steam or heat transfer fluid. The condensate is supplied to the first decanter attachment, wherein the condensate 132562.doc 15 200909408 is separated into an organic phase (with organic entrainer A, w horse master, containing a small amount of organic entrainer by-product, water and some methyl acetate, For _ _ _ _ and other organic matter) and a water phase containing organic entrainer by-products and a small amount of a 'in-entrainer. The organic phase mainly containing the organic entrainer is introduced into the distillation column via the line 5. The water phase is passed through line 6 for recovery of the right secret + gene, the recovery of the organic entrainer in the recovery tower D2 and the organic entrainer by-products are passed through the pipeline 8 into a Chengbo on the eighth item of the recycling decanter Within F2. It is also possible to use the first decanter F1 to introduce the system into a 7 π, any additional entrainer that is broken by the brother.

The recovery column D2 is heated by steam (by direct spraying or via a reboiler), and the vapor line 8 outside the column passes through the condenser Ε3. The recyclate contains a packed section or a tray section. The bottom product withdrawn from the bottom of the L sinter U2 contains water having a relatively lower organic content (e.g., but not limited to, less than about 1 wt%) compared to the input feed stream 6 from the recovery. From the recovery column D2, a recycle decanter ρ2 is fed via line 8 through condenser E3. Feed stream 8 primarily comprises an organic entrainer and an organic entrainer by-product. Any water in the feed stream 8 can be separated at the recycle decanter (4) and fed via the line to the decanter F1 or recovery column (1). The organic inflammatory tape and the organic entrainer by-product are fed into the dehydration column 经由1 via line 9, below the feed line i. The by-product of the entanglement entrainer is converted into an organic entrainer by conversion in the dehydration column 1 by the brewing reaction. Figure 2 illustrates an alternative configuration of Figure 1 in which the condenser E3 is located inside the recovery column D2. The non-condensable fraction can be fed from line E1 to recovery column D2 via line 11 and the feed point is located between the packing section or tray section of the recovery tower D2 and the lower packing section or tray section. The separator unit can be provided above the packing section or tray section and the lower packing section or tray section in the recovery tower 2 . The feed line 6 from the first tilt 132562.doc 200909408 separator F1 is fed into the recovery column D2 at a position between the lower separator unit and the lower packing section or tray section. The line 8 fed to the recycle decanter ρ2 exits the recovery column D2 at a position just above the lower separator unit and below the upper packing section or tray section. Figure 3 illustrates an alternative configuration of Figure 2 in which the recycle decanter is located inside the return tower D2. ® 4 illustrates an alternative configuration of Figure i_3 where the entrainer by-product can be esterified in the esterification reactor R1 rather than in the azeotropic distillation column D1. This configuration can also use the internal decanter of Figure 3 to perform phase separation tasks. Figure 6 illustrates an alternative configuration of Figure 4 in which line 8 can be cooled by another heat exchanger E4. Figure 7 illustrates an alternative configuration of the crucible 4 in which the line 8 fed to the recycle decanter exits the recovery column D2 at a location within the upper packing section or tray section. Further, the line 15 fed to the first decanter F 1 leaves the recovery column D2 at a position above the packing section or the tray section and the lower packing section or tray section above the tower D2. Figure 8 illustrates an alternative configuration of Figure 7, in which line 8 can be cooled by another heat exchanger E4. Figure 9 illustrates an alternative configuration of Figure 4 in which the line enthalpy 6 can feed the entrainer by-product into line 9 before being fed into the esterification reactor IU. - The following examples further illustrate the invention. Comparative Example 1 A pilot scale dehydration column system was operated in the configuration of Figure 5 to demonstrate the accumulation of organic entrainer by-products in the topping. The test system was operated at a top pressure of 4 bar for several days. From the spi into the dehydration column (1), I32562.doc 200909408 was sampled to demonstrate the increase in the by-product of the organic deaturant in the top of the column. The organic cooling agent used was 99% pure n-propyl acetate having less than 1% propanol impurities. The results are shown in Table 1 below. Table 1 Days of propanol at SP1 (wt%) 1 2.3 2 4.6 3 6.5 4 5.3 5 7.2 6 9.2 Example 2 A laboratory-scale batch reaction was run several times to demonstrate that the conversion of the organic entrainer by-product was restored to Organic entrainer. The conditions in the autoclave were designed to be similar to the lower portion of the azeotropic distillation column. To demonstrate the conversion reaction, n-propyl acetate (ηΡΑ) was used as an entrainer and propanol (pr〇H) was used as an entrainer by-product to feed into a batch reactor. Water and acetic acid were also fed into the batch reaction dad as detailed in Table 2. After each run, the propanol concentration was monitored by sampling the liquid in the kettle. The feed composition, system, "percent reduction of residual propanol, residence time and temperature of the batch reactor" were recorded. The results are shown in Table 2 below. 132562.doc 200909408 Table 2 Test number in batch reactor Feed retention time Min temperature °c ?1*011 reduction % PrOHg nPAg acetic acid g water g 1 1 1.5 80 20 15 150 45 2 1 1.5 80 2ϋ 1δ 150 48 3 1 1.5 80 20 ~ 60 150 59 4 1 1.5 80 20 15 150 56 5 0.2 0.3 80 20 15 150 52 6 3 4.5 80 20 15 150 61 7 1 1.5 90 10 15 155 77 — 8 1 1.5 75 25 148 64 Example 3 Proof of esterification reactor R1 using Aspen simulation and kinetic model The effectiveness of the esterification reactor feed is generated by the Aspen simulation experiment and applied to the kinetic model of the n-propyl acetate hydrolysis/acetation reaction. The n-propanol conversion is thus determined. Reactor R1 feed consisting of

The Aspen simulation experimental configuration is roughly as shown in Figure 4, except that: • The methyl acetate recovery tower D2 is modeled in two separate sections (top section and bottom section) * Organics from the recycle decanter (line 9) Only a part of it passes through the esterification reactor. The remainder is mixed via line 5 and returned to the column by reflux. • PX wash tower in the ASPEN model • Hydrolysis sections exist at different locations to simulate entrainer hydrolysis. The fixed concentration of propanol in reflux (line 5) is controlled by the value of the conversion score specified in the esterification reactor section.

The Aspen simulation experiment consists of the following main unit operations: • Dehydration Tower D1 and Reboiler E1: Specifications: Top Pressure? =3 8 bar 'bottom pressure P=4 bar, controlled by "design specifications" for the bottom product I32562.doc -19- 200909408 • Dehydration tower condenser E2:Specification: Τ=115-1161 • Acetate A Ester recovery tower: ρ = 3.65-4 bar • Esterification reactor R1 : Specification: Ρ = 7 bar, T = 160 ° C Calculate the esterification rate using the following formula: ^1 = 0.23^^][狮]-哜_ Brain ^ V 5 ) The results of the simulation and kinetic models are listed in Table 3 below. Table 3 Concentration of PrOH line 14+ line 9 in test line 5 (mol/1) [nPA][H20]/ [PrOH] [HOAc] Esterification rate (mol/l.hr) No. wt% HOAc h2o nPA PrOH d[PrOH]/dt 9 1.56 6.47 2.58 2.81 0.18 6.37 0.072 10 2.19 6.47 2.63 2.78 0.25 4.60 -0.029 11 4.28 6.34 ~2J2~ 2.72 0.47 2.50 -0.340 Example 4 Esterification reactor R1 was proved using Aspen simulation and kinetic model Effectiveness. The Aspen simulation experiment was run in the configuration of Figure 6 and the acetonitrile reactor feed concentration for the kinetic model was generated as in Example 3. The simulated experimental configuration differences, single operation instructions, and esterification rate calculations were the same as in Example 3. The results are shown in Table 4 below. Table 4 Test number PrOH wt% in line 5 Concentration of line 14 + line 9 (mol/1) [nPA][H20]/ [PrOH] [HOAc] Esterification rate (mol/l.hr) 12 13 2.33 4.29 6.98 6.53 n2u 1.9P—T87^~ nPA 2.76 o nn PrOH 0.25 2.96 d[PrOH]/dt -0.167 Example 5 Using Aspen simulation and kinetic model to prove the effectiveness of the esterification reactor ri 132562.doc -20· 200909408 . The Aspen simulation experiment was run in the configuration of Figure 7 and the esterification reactor feed concentration for the kinetic model was generated as in Example 3. The simulated experimental configuration differences, unit operating instructions, and esterification rate calculations were the same as in Example 3. The results are shown in Table 5 below. Table 5 Concentration of PrOH line 14+ line 9 in test line 5 (mol/1) [ηΡΑ][Η20]/ [PrOH] [HOAc] Esterification rate (mol/l.hr) No. Wt% HOAc H20 ηΡΑ PrOH d[PrOH]/dt 14 2.07 6.75 2.73 2.44 0.30 3.30 -0.158 15 3.91 6.75 2.82 2.37 0.53 1.87 -0.513 Example 6 The effectiveness of the esterification reactor R1 was demonstrated using Aspen simulation and kinetic models. The Aspen simulation experiment was run in the configuration of Figure 8 and the esterification reactor feed concentration for the kinetic model was generated as in Example 3. The simulated experimental configuration differences, unit operating instructions, and esterification rate calculations were the same as in Example 3. The results are shown in Table 6 below. Table 6 Concentration of PrOH line 14+ line 9 in test line 5 (mol/1) [ηΡΑ][Η20]/ [PrOH] [HOAc] acetification rate (mol/l.hr) No. Wt% HOAc h2o ηΡΑ PrOH d[PrOH]/dt 16 3.90 7.01 1.90 2.41 0.53 1.22 -0.650 Example 7 Operation of a laboratory-scale tubular reactor system to demonstrate the effectiveness of the esterification reactor R1 and verify the Aspen simulation and kinetics of Examples 3-6 The result of the model. The laboratory-scale tubular reactor system has a pump with a 10 ml head to draw the feed composition into a 1/16" outer diameter preheat coil and then pump into a 1/2 equipped HITRAN insert. In the outer diameter tubular reactor, connect 132562.doc -21 - 200909408 into the cooling coil of 1/16" outer diameter, and finally draw into the sample container. Preheat coil and tubular reactor are placed The temperature is set in about 16 Torr of its oil bath. The cooling coil is placed in a cooling bath set at a temperature of about 2 (rc). The system has a back pressure regulator with a pressure set at about U bar just before the sample container. (to suppress boiling). The reactor residence time is about 25 minutes. At the beginning of each test, water is withdrawn through the system and the oil bath is set to the desired temperature. When the set temperature is reached, the water is replaced with the feed solution. The unit is operated for a sufficient time to ensure that the liquid flowing through the unit represents the feed solution and all water has been withdrawn. Three ml samples are collected per experiment. Samples of the feed and product are analyzed via gas chromatography. Use standard KF titration solution' by Ka The ri Fischer test measures the water concentration for a 1 μ μ μ injection sample. The results for the conversion of propanol (pr〇H) are listed in Table 7 below.

Although the present invention has been described in connection with the specific embodiments thereof, it is apparent that those skilled in the Accordingly, the present invention is intended to cover all such alternatives, modifications, and BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic flow chart illustrating an embodiment of the present invention in which water is separated from an aliphatic carboxylic acid via azeotropic distillation, and an organic detachment agent by-product 132562.doc -22· 200909408 Recycling. Figure 2 is a schematic illustration of an alternate embodiment of the present invention. Figure 3 is a schematic illustration of another alternate embodiment of the present invention. Figure 4 is a schematic illustration of another alternate embodiment of the invention wherein the entrainer by-product undergoes an esterification reaction in an external reaction vessel. Figure 5 is a schematic diagram of the test scale configuration as described in Comparative Example 1. Figure 6 is a schematic illustration of another alternate embodiment of the invention wherein the entrainer by-product undergoes an esterification reaction in an external reaction vessel.

Figure 7 is a schematic illustration of another alternate embodiment of the invention wherein the entrainer by-product undergoes an esterification reaction in an external reaction vessel. Figure 8 is a schematic illustration of another alternate embodiment of the invention wherein the entrainer by-product undergoes an esterification reaction in an external reaction vessel. Figure 9 is a schematic illustration of another alternate embodiment of the invention wherein the entrainer by-product undergoes an esterification reaction in an external reaction vessel. [Main component symbol description] 1, 2, 3, 4, 5 > Pipeline 6 ' 7 ' 8 , 9, 10, 11' 12 ' 13, 14, 15, 16 D1 Dehydration tower D2 Recovery tower E1 Reboiler E2 Tower top condenser system / dehydration tower condenser E3 condenser

U 132562.doc 23· 200909408 E4 Heat exchanger / cooler FI First decanter F2 Recycling decanter R1 Esterification reactor 132562.doc -24-

Claims (1)

200909408 X. Patent application scope: 1. A method for azeotropic distillation of raw materials, wherein the raw material and water, the method comprises: · 3 h & rebel (4) in the organic entrainment material under the material _ 1 a liquid organic entrainer, an organic entrained vapor phase component, and a seat and water (8) having a water content of the raw material and a phase composition of the aliphatic acid containing the organic compound; The recycle of the organic entrainer by-product is lower than the position at the feedstock of the feedstock. The distillation is converted to the organic central zone agent. The method of organic entrainer by-product 2 item 1 wherein the organic entrainer has a boiling point in the range of from about 4 o'clock to about the same time as the n-butyl acetate point of the acetic acid. 3. The method of =1, wherein the organic entrainer has a boiling point in a target range of from about m: to about 126 c. The method of claim 1 wherein the organic entrainer is at least one ester selected from the group consisting of n-butyl acetate, isobutyl acetonate, ethyl bromide, isopropyl acetate, and a mixture thereof. The method of claim 1, wherein the organic entrainer The product is at least one member selected from the group consisting of propanol, butanol, an alcohol corresponding to an organic entrainer, and mixtures thereof. 6. The method of "monthly item 1, which includes the following additional steps (1) removing the component of step (4) from the steaming process; (8) condensing it to form a phase and phase, (10)) recycling the organic phase to the steaming process; () 'flying water Phase, to recover organic entrainer and organic entrainer by-product 132562.doc 200909408 and form a second vapor phase. 7. The method of claim 6, wherein the organic phase of step (iii) comprises a concentration of about 1 weight. % to about 15% by weight of the organic entrainer by-product. 8. The method of claim 6, comprising the additional steps of: condensing the second &phase; and (vi) condensing step (v) At least a portion of the material is recycled to the stripping step (iv). 9. The method of claim (8) wherein the conversion of step (8) comprises the esterification of the by-product of the organic side. 10. A method of steaming a feedstock (4), wherein the feedstock comprises aliphatic treason and water. The method comprises: (a) azeotropic distillation in the presence of an organic entrainer to produce a water content comprising the feedstock. a lower water content of the aliphatic (four): liquid component and a vapor phase component comprising the organic entrainer, organic entrainer by-product, and water; (b) converting the organic entrainer by-product to the organic collet And (c) returning the organic entrainer to the azeotropic distillation. 11. The method of claim H) wherein the organic strip agent has a boiling point in the range from about the boiling point of isopropyl acetate to about the boiling point of n-butyl acetate. 12. The method of claim 1 (), wherein the organic entrainer has a boiling point in the range of from about ah to about 126 °C. 13. The method of claim 10, wherein the organic entrainer is at least one of the following groups: vinegar, n-butyl acetate, diisoacetic acid, n-propyl acetate, isopropyl acetate, and mixture. The method of claim 1 , wherein the organic entrainer by-product is at least one 132562.doc 200909408 species selected from the group consisting of: propanol, butanol, corresponding to the organic Entrained alcohol and mixtures thereof. 15. The method of claim 1, wherein the other steps of the package s U are: (i) removing the vapor phase component of step (a) from the distillation 裎 φ column, and (11) condensing it Forming an organic phase and an aqueous phase; (out) recycling the organic phase to the steaming process; Gv) stripping the aqueous phase to recover the right-handed organic entrainer and the organic entrainer by-product and forming a second Steam phase. Γ % The method of claim 15 wherein the organic phase of the step (out) comprises an organic entrainer by-product having a concentration of from about 2% by weight to about 15% by weight. 17. The method of claim 15, comprising the following additional steps from the following: (¥) condensing the second vapor phase; and (vi) causing at least a portion of the AX order/break of the step (¥) Recycled to the stripping step (W). The method of claim 1 wherein the conversion of step (b) comprises an esterification reaction of the organic inflammatory agent by-product. A-type method for azeotropic evaporation of raw materials, wherein the raw material comprises aliphatic tickic acid and water, the method comprises: (4) performing azeotropic steaming in the presence of an organic solvent to produce a mixture comprising the same Water content with lower water content (IV) U phase component and vapor phase component containing the organic entrainer, organic inflammation agent by-product and water; (b) Good by-product in the organic entrainer and organic entrainer The vapor phase component is condensed under condensation to form an organic phase and an aqueous phase, (c) the organic phase of step (b) is returned to the azeotrope column; (d) step (b) The aqueous phase is purified to remove the organic entrainer and the organic binder 132562.doc 200909408 by-product from the water; and (4) (iv) (iv) entrainer and the base-based Φ batch are returned from the &Azeotrope...; The location at which the feedstock is fed, where the ancient drag product is converted to the organic entrainer. ~~Organic entrainer pair 20.If requested, the propylene vinegar boil... The organic entrainer has a boiling point in the range of the boiling point of about acetic acid, such as apex, and, n-butyl acetate. 'About lit 1 of the organic entrainer has (10). C to , is the boiling point in the range of 26 C. 22. The method of claim 19, wherein the organic entrainer is at least one selected from the group consisting of: tetradecyl acetate 7 7 species from r ^ -r ^ 骎正丁自曰, acetic acid Isobutyl ester, ethyl I propyl sulfonium acetate, isopropyl acetate, and mixtures thereof. The method of claim 2 wherein the organic entrainer by-product is at least one member selected from the group consisting of propanol, butanol, an alcohol of the organic entrainer, and mixtures thereof. ^ 24. The vinegarization reaction of the bean Cj by-product as described in claim 19. (4) The conversion comprises the method of the organic binder 25:=19, wherein the organic phase of the step (4) comprises an organic entrainer by-product having a concentration of from (4)% to about 15% by weight. 26. The method of claim 9, wherein the basin φ 1/2. 0^, .u, and the step (b) further comprise (1) separating the organic phase from the aqueous phase; and wherein the step is performed (the purification operation of the sentence comprises ( i) forming a stream comprising an organic entrainer, an organic entrainer by-product, and water, and (9) separating the stream into an organic phase and an aqueous phase comprising the organic entrainer and the compound. The method of claim 19, wherein the step (8) further comprises (1) separating the organic 132562.doc 200909408 phase from the aqueous phase; and wherein the purifying operation of the step (4) comprises (1) stripping the aqueous phase of the step (8) to produce the organic phase An entrainer, an organic side agent by-product, and a vapor phase of water, (9) condensing the vapor phase organically and under the condition that the organic entrainer, the organic entrainer by-product, and water are condensed, and the organic entrainer, The organic entrainer by-product and water are separated into an organic phase and an aqueous phase comprising the organic entrainer and the organic entrainer by-product. 28. A method for co-boiling a raw material, wherein the raw material comprises an aliphatic acid and water, The method contains: ' (4) in a liquid evaporation component in the presence of a machine entrainer to produce a liquid component of the aliphatic acid containing and having a lower water content than the water in the raw material and comprising the organic entrainer and the organic entrainer a by-product and a vapor phase component of water; W condenses the vapor phase component under conditions of the organic entrainer, organic entrainer by-product, and water to condense and form an organic phase and an aqueous phase; 7 (4) the step (8) the organic phase is returned to the common distillation, and the aqueous phase of the step (8) is purified to remove the organic entrainer and the organic entrainer by-product from the water; (4) converting the organic entrainer by-product into The organic (d) agent (f) returns the organic entrainer to the azeotropic distillation. 29. If desired: micro-method 'where the organic band-trapping agent has a boiling point of about 曰S曰 in about acetic acid to about the boiling point of n-butyl acetate The method of claim 28, wherein the organic entrainer has a boiling point in the range of about 126. 88 88 ! 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 Organic clip ~ Wang) ~ species selected from 132562.doc 200909408 consists of the following Group of vinegar: n-butyl vinegar acetate, isobutyl acetate, n-propyl acetate, isopropyl acetate, and mixtures thereof. 32. The method of claim 28, wherein the organic entrainer by-product is at least one member selected from the group consisting of propanol, butanol, an alcohol corresponding to the organic entrainer, and mixtures thereof. 33. The method of claim 28 wherein the conversion of step (4) comprises an esterification reaction of the organic entrainer by-product. 34. The method of claim 28, wherein the organic phase of step (4) comprises from about 2% to about 15% by weight of the organic entrainer by-product. 35. The method of claim 28, wherein the step (8) further comprises (1) separating the organic phase from the aqueous phase; and wherein the purifying operation of step (d) comprises (1) forming an organic entrainer, an organic entrainer by-product And the water stream, and (Π) separate the stream into an organic phase and an aqueous phase comprising the organic entrainer and the organic entrainer by-product. 36. The method of claim 35, wherein the step (4) further comprises cooling the stream and then separating. C. 37. The method of claim 35, wherein the step (the phantom stream exits the recovery column at a location within the upper packing section or tray section. 38. The method of claim 35, wherein the other organic entrainment Addition of the by-product to the organic phase of step (d) (ii). The method of claim 28, wherein the step (1) further comprises (1) separating the organic phase from the aqueous phase; and wherein the step (d) the purifying operation comprises (丨) stripping the aqueous phase of step (b) to produce a vapor phase comprising the organic entrainer, organic entrainer by-product, and water '(ii) in the organic entrainer, Organic loss zone 132562.doc 200909408 The by-product of the agent and the water are condensed by the cold anger & condensing conditions, and (πυ is separated into the organic entrainer, the organic carrier agent by-product and water The organic phase and the aqueous phase of the organic entrainer and the organic entrainer by-product. 40. The method of claim 39, wherein the step (4) (Η) further comprises after the organic entrainer, the organic entrainer by-product, and the water are condensed Cooling it. 41. The method of claim 39, wherein The organic entrainer, organic entrainer by-product, and water of step (d) (ii) exit the recovery column at a location within the upper packing section or tray section. 42. The method of claim 39, wherein another organic The entrainer by-product is added to the organic phase of the step (d) (iii). The method of any one of the preceding claims, wherein the tasting acid is acetic acid. 132562.doc