GB2525989A

GB2525989A - Combined PTA and PET plant waste water purification and recycle

Info

Publication number: GB2525989A
Application number: GB1507465.1A
Authority: GB
Inventors: Robert Edward Neate; Finbar Gerald Mcdonnell; Alexander Stuart Coote
Original assignee: Invista Technologies Sarl; Invista Technologies SARL Switzerland
Current assignee: Invista Technologies Sarl; Invista Technologies SARL Switzerland
Priority date: 2015-04-30
Filing date: 2015-04-30
Publication date: 2015-11-11
Also published as: GB201507465D0

Abstract

A process for treating aqueous condensate liquor from a polyester plant 300 in an integrated terephthalic acid polyester plant comprises: contacting a portion of the aqueous condensate liquor from a polyester plant with an aqueous mother liquor from a terephthalic acid purification plant process to form a combined stream. The combined stream is provided to a pure plant mother liquor solvent extraction process 400 to separate the combined stream into an aqueous stream and organic stream. The aqueous stream is contacted with an alkali to form a pH adjusted stream and the pH adjusted stream is contacted with a filter to form a treated stream. The treated stream is contacted with a reverse osmosis unit to form an RO permeate stream. The permeate stream may be recycled back into the integrated PTA PET plant. Advantageously the process provides for water recovery and better water recycling thus reducing operating costs and providing a more environmentally friendly process.

Description

COMBINED PTA AND PET PLANT WASTE WATER PURIFICATTON

AND RECYCLE

FTELD OF THE TNVENTTON

100011 The invention relates to methods for purifying aqueous waste streams from an integrated pure terephthalic acid (PTA) and polyester (PET) manufacturing plant and recycling of the purified water back into the integrated PTA -PET plant.

BACKGROUND OF THE INVENTION

100021 Poly(ethylene terephthahte) (PET) resins are widely produced and used, for example, in beverage and food containers, thermoforming applications, textiles, and as engineering resins.

PET is a polymer formed from ethylene glycol and terephthalic acid (or dimethy terephthalate).

Terephthalic acid (1,4-benzenedicarboxylic acid) generally must be synthesized for use as a reactant, The terephthalic acid required as a reactant for PET production is a form of terephthalic acid known as "purified terephthalic acid" (PTA), which generally contains over 99.99 weight percent of terephthalic acid, and less than 25 ppm 4-carboxibenzaldehyde (4-CBA).

[0003] On the commercial scale, purified terephthalic acid (PTA) suitable for use in PET production is generally prepared in a two-stage process comprising paraxylene oxidation followed by purification of the crude oxidation product. First, paraxylene is oxidized (e.g., with air) to provide crude terephthalic acid (CTA), such as described, for example, in U.S. Patent No. 2,833,816 to Saffer et at, which is incorporated herein by reference, The oxidation reaction is generally conducted in a solvent comprising an aliphatic carboxylic acid (e.g., acetic acid) and in the presence of a metal catalyst (e.g., a cobalt or manganese salt or compound).

[0004] The crude terephthalic acid produced by this oxidation reaction is then purified, as it is typically contaminated by such impurities as 4-carboxybenzaldehyde, p-toluic acid, and various colored impurities that impart a yellowish color to the terephthalic acid, Purification of the CTA typically requires at least one chemical transformation in addition to at least one physical procedure (e.g., crystallization, washing, etc.). One common chemical transformation is hydrogenation of the CTA, which can transform one of the main impurities in the CTA, 4-carboxybenzaldehyde, to p-toluic acid, which is easier to remove, Thus, CTA is generally dissolved in water and subjected to hydrogenation in the presence of a Group VIII noble metal hydrogenation catalyst (e.g., a supported platinum or palladium catalyst) as a first step of purification. The purified terephthalic acid is recovered by one or more physical procedures.

For example, PTA is generally obtained via crystallization of the product from water, as a majority of the impurities, including p-toluic acid, acetic acid, and small amounts of terephthalic acid remain in the solution. The PTA can be recovered by such means as filtration or centrifugation and washed to provide the pure desired material. The remaining solution is referred to as "pure plant mother liquor" (PPML).

100051 The PPML remaining after production of purified terephthalic acid generally comprises some concentration of impurities. Although the PPrvIL can be treated for release as effluent water on a commercial scale, it can be beneficially purified and recycled for use in the production of more terephthalic acid, Further, the impurities typically include crude terephthalic acid, which can be recovered and purified, as well as p-toluic acid, which can readily be converted into terephthalic acid. The recovery of these dissolved organic acids using solvent extraction is known as pure plant mother liquor solvent extraction (PPMLSX). The aqueous eluent from PPMLSX is not suitable for direct recycle within a PTA plant or for direct supply to a Reverse Osmosis (RO) based technology, such as those conventionally used for desalination of water, without further treatment.

100061 For the PET process, the esterification step produces process waste water that is currently treated, recycled, and discharged independently from the PTA process waste water, For example, WO1996035654 and WO2010020442 describe the recovery of ethylene glycol from and the purification of PET plant waste water via reverse osmosis.

[0007] Several prior art references disclose combined PTA -PET plants and methods of integrating to improve efficiency, however, none disclose integration of waste water streams.

For example, [WO20020 10228] discloses the possibility of feeding PET polymer to an oxidation process, allowing recovery of terephthalic acid from the process. Co-oxidation of paraxylene and PET is discussed; however, there is no mention of integration between PTA and PET plans or of water generated from a PET production plant. Another reference [US8 198397] discloses the integration of steam heating between TA and PET plants. It refers to steam raised in a thel fired boiler, to replace the use of heat transfer fluids. It mentions the use of such steam in a purification plant as an indirect heat source either for mixed feed streams or to heat another stream, such as acetic acid and water, where this other stream may then be directly introduced.

[US8 I 98397j maintains a separation between process streams and the boiler steam and does not discuss the use or recycle of process water exiting the PET plant. [US6642407] describes a process for converting carboxylic acids to glycol esters and then distilling the esters, prior to sending the dicarboxylic acid esters to a polymeriser. The reference does not discuss the fate of the esterifer water, other than a single sentence that says water may be removed from the esterifier, It mentions conventional prior art DM1 processes and that these need removal of methanol from the esterifer. There is no mention of feeding back water to the oxidation reactor.

CN103232341A discusses the recovery of terephthalic acid by treating an aqueous waste water stream from a downstream PET thbric production process. The stream is treated using a combination of absorption, acidification, and filtration.

100081 Water management is a growing issue for all industries globally, especially in areas where there is a shortage of fresh water, Currently, most combined PTA -PET phnts separately treat and use demineralized water for purification of the product on a "once-through" mode.

"Once-through" means that little or no recycling of water is employed; with a major portion of the water used in the process being discharged as liquid effluent. The costs associated with managing water are increasing and by employing better water recycle techniques; the overall operating cost of a PTA plant can be reduced while making it more enviwnmentally friendly.

BRTEF SUMMARY OF THE INVENTION

10009] Water recovery systems developed for TA aqueous effluent permits a more economic method for combined processing / water recovery for an integrated PTA -PET plant, or for PTA and PET plants located in sufficient proximity to permit sharing of a facility. Further, a combined process provides overall water recycle efficiency, greater than that achieved for two stand-alone systems, and water recovered can be recycled to any suitable point in either plant.

Therefore, it would be desirable to modify existing terephthalic acid pure plant mother liquor solvent extraction (PPMLSX) and contaminant removal (RO) equipment to handle an aqueous condensate liquor stream from a PET process in a combined PTA -PET plant.

1000101 PCT Application No. PCT/US13/67304 provides an exemplary description of the PPMLSX process, which is herein incorporated by reference in its entirety. U.S. Provisional Application No. 61/720,675 provides an exemplary description of the contaminate removal process (RO), which is herein incorporated by reference in its entirety. The PPMLSX process permits recovery of a major portion of the organic acids from the PPML. Tn doing so, the process generates an aqueous waste stream, which combines the majority of the aqueous output of both oxidation and purification process steps. The aqueous stream generated by the PPMLSX process is not suitable for direct recycle in a PTA plant, as it contains some soluble organic acids and metal salts, as well as suspended organic acid solids. However, the organics separated from aqueous stream may be recycled to the oxidation reactor. Conversely, the combination of the preferred operating temperature range of the PPMLSX process and the presence of the aforementioned impurities means the stream can be satisffictorily processed by direct supply to a feed stream to a contaminant removal process. The contaminant removal process results in a clean water stream that can be discharged, used in other PTA or PET processes, or recycled to the pure plant process.

1000111 The PET process generates a waste water stream from the esterifier step. This results in any trace volatile organics (such as acetaldehyde, 2 methyl 1,3 dioxolane, 1,4 dioxane, and monoethylene glycol) which may be present in the waste water being transferred to the PPMLSX process. After treatment in the PPMLSX process, any remaining high boiling oxidizable organics (after passing through an azeotropic distillation processes) are oxidized in the oxidation reactor, resulting in recovered TA from any TA oligomers that may be present. The aqueous stream resulting from the PPMLSX process is passed through the contaminant removal process.

Here, a clean water stream is generated that can be recycled back into the pure plant process, used in other PTA or PET processes, or discharged.

1000121 In one aspect of the invention is provided a process for treating aqueous condensate liquor from a PET plant in an integrated terephthalic acid -polyester plant comprising: contacting at least a portion of the aqueous condensate liquor from a PET plant with an aqueous mother liquor from a PTA pure plant process to form a combined stream, providing the combined stream to a pure plant mother liquor solvent extraction process to separate the combined stream into an aqueous stream and organic stream, contacting the aqueous stream with an alkali to form a pH adjusted stream, contacting the pH adjusted stream with a filter to form a treated stream, and contacting the treated stream with a reverse osmosis unit to form an RO permeate stream. The aqueous condensate liquor from the PET plant can contain traces of volatile organics, including U to 3 wt.% of acetaldehyde; U to 3 wt.% 2 methyl 1,3 dioxolane; 0 to 0,5 wt.% 1,4 dioxane; 0 to 2 wt.% monoethylene glycol and 0 to 1 wt% acetic acid. The RD permeate stream may be contacted with a crude terephthalic acid stream, sent to other PTA or PET processes, or discharged. The organic stream can be sent to an azeotropic distillation system to separate out the heavy organics for recycle to a PTA oxidation reactor.

1000131 In another aspect of the invention is pwvided a process for treating aqueous condensate liquor from a PET plant in an integrated terephthalic acid -polyester plant comprising: providing at least a portion of the aqueous condensate liquor from a PET plant to pure plant mother liquor solvent extraction process, providing an aqueous mother liquor from a PTA pure plant process to the pure plant mother liquor solvent extraction process, separating the condensate liquor and mother liquor streams into an aqueous stream and organic stream, contacting the aqueous stream with an alkali to form a pH adjusted stream, contacting the pH adjusted stream with a filter to form a treated stream, and contacting the treated stream with a reverse osmosis unit to form an RD permeate stream. The aqueous condensate liquor from the PET plant can contain traces of volatile organics, including 0 to 3 wt.% of acetaldehyde; 0 to 3 wt.% 2 methyl 1,3 dioxolane; 0 to 0.5 wt.% 1,4 dioxane; 0 to 2 wt.% monoethylene glycol and 0 to I wt% acetic acid. The RO permeate stream may be contacted with a crude terephthalic acid stream, sent to other PTA or PET processes, or discharged. The organic stream can be sent to an azeotropic distillation system to separate out the heavy organics for recycle to a PTA oxidation reactor.

1000141 In a further aspect of the invention is provided a process for treating aqueous condensate liquor from a PET plant in an integrated terephthalic acid -polyester plant comprising: contacting at least a portion of the aqueous condensate liquor from a PET plant with an azeotropic distillation overhead gas stream to form a combined stream, providing the combined stream to a pure plant mother liquor solvent extraction process, providing an aqueous mother liquor stream from a PTA pure plant process to the pure plant mother liquor solvent extraction process, contacting the combined stream and mother liquor stream in the pure plant mother liquor solvent extraction process to form a second combined stream, separating the second combined stream into an aqueous stream and organic stream, contacting the aqueous stream with an alkali to form a pH adjusted stream, contacting the pH adjusted stream with a filter to form a treated stream, and contacting the treated stream with a reverse osmosis unit to form an RD permeate stream, The aqueous condensate liquor from the PET plant can contain traces of volatile organics, including U to 3 wt.% of acetaldehyde; U to 3 wt.% 2 methyl 1,3 dioxolane; 0 to 0,5 wt,% 1,4 dioxane; U to 2 wt,% monoethylene glycol and 0 to I wt% acetic acid.. The RD permeate stream may be contacted with a crude terephthalic acid stream, sent to other PTA or PET processes, or discharged. The organic stream can be sent to an azeotropic distillation system to separate out the heavy organics for recycle to a PTA oxidation reactor, 1000151 In yet another aspect of the invention is provided a process for treating aqueous condensate liquor from a PET plant in an integrated terephthalic acid -polyester plant comprising: providing at least a portion of the aqueous condensate liquor from a PET plant to pure plant mother liquor solvent extraction process, separating the condensate liquor into an aqueous stream and organic stream, contacting the aqueous stream with an alkali to form a pH adjusted stream, contacting the pH adjusted stream with a filter to form a treated stream, and contacting the treated stream with a reverse osmosis unit to form an RD permeate stream. The aqueous condensate liquor from the PET plant can contain traces of volatile organics, including U to 3 wt% of acetaldehyde; 0 to 3 wt% 2 methyl 1,3 dioxolane; U to 0,5 wt,% 1,4 dioxane; U to 2 wt,% monoethylene glycol and U to I wt% acetic acid. The RO permeate stream may be contacted with a crude terephthalic acid stream, sent to other PTA or PET processes, or discharged. The organic stream can be sent to an azeotropic distillation system to separate out the heavy organics for recycle to a PTA oxidation reactor.

BRIEF DESCRIPTIDN DF THE DRAWINGS

1000161 FIGURE I discloses one aspect of the process wherein a portion of the aqueous condensate liquor from a PET plant is treated along with the aqueous mother liquor from the pure plant.

1000171 FIGURE 2 discloses another aspect of the process wherein a portion of the aqueous condensate liquor from a PET plant is treated directly in the pure plant mother liquor solvent extraction process, 1000181 FIGURE 3 discloses a further aspect of the process wherein a portion of the aqueous condensate liquor from a PET plant is mixed with the overheads from an azeotropic distillation system prior to treatment in the pure plant mother liquor solvent extraction process, 1000191 FIGURE 4 discloses yet another aspect of the process wherein a portion of the aqueous condensate liquor from a PET plant is treated in the pure plant mother liquor solvent extraction process.

1000201 FIGURE 5 discloses a pure plant mother liquor solvent extraction process.

1000211 FIGURE 6 discloses a contamination removal process on a pure plant mother liquor aqueous stream.

1000221 FIGURE 7 discloses a pure plant mother liquor solvent extraction process.

DETAILED DESCRIPTION OF THE INVENTION

1000231 The present invention provides systems and methods for the treatment of organic and aqueous waste streams in an integrated terephthalic acid (PTA) -polyester (PET) plant. More specifically, the invention provides systems and methods for treating aqueous condensate liquor from a PET plant. The treatment is a combination of pure plimt mother liquor solvent extraction (PPMILSX) on the aqueous condensate liquor md contaminate removal of the resulting aqueous stream. This can be combined with the treatment of the pure plant mother liquor (PPML) that is generated during the hydrogenation of crude terephthalic acid into PTA, PCT Application No. PCT/IJSI3/67304 provides an exemplary description of the PPMLSX process. U.S. Provisional Application No, 61/720,675 provides an exemplary description of the contaminate removal process.

1000241 The manufacturing process for polyethylene terephthalate, used for both polyester fibres and bottle resin, is carried out, totally or in part, in a series of melt phase reactors. In the Tnvista licensed process for polyethylene terephthalate there are usually 3 melt phase reactors: esterifier, UFPP (Up Flow Pre-Polymeriser) and finisher. Other polyethylene terephthalate manufacturing processes may use more or less reactors, All 3 reactors typically operate at temperatures above 255C while the operating pressure reduces from super-atmospheric pressure in the first reactor (esterifier) to nearly full vacuum in the fina' reactor (finisher). The raw materials for the process are ethylene glycol and phthalic acids, The phthalic acids are typically 100% terephthalic acid for polyester fibre but may contain up to 5% isophthalic acid for bottle resins, Tn the esterifier ethylene glycol is reacted with phthalic acid to form a liquid oligomer stream and a by-product vapour stream. The by-product vapour stream from the esterifier containing excess ethylene glycol, water vapour and small quantities of organic compounds is fed to a distillation column which separates ethylene glycol, which is recycled for reuse, from the water and by-product organic compounds, which are sent for further treatment, The oligomer is then polymerised in the UFPP and finisher to form polymer with ethylene glycol, water and small quantities of organic compounds as by-products. The by-product stream from the polymerisers is recycled directly or indirectly (ie via the esterifler) back to the esterifier distillation column to facilitate reuse of the recycled ethylene glycol.

1000251 Normally the waste aquaeous stream from the top of the esterifier distillation column is sent to a stripping column where the organic compounds are removed from the water by stream of steam or hot air, The organic compounds leaving the stripping column with the steam or hot air vapour stream are used as a supplementary fuel in the fired heaters used as the primary heat source for the polyethylene terephthalate process. The aqueous stream leaving the stripping column contains only trace quantities of organic compounds and is normally sent to the site effluent treatment system.

1000261 The commercial production of PTA typically begins with the liquid-phase oxidation of a p-phenylene compound to give crude (i.e., impure) terephthalic acid, The p-phenylene compound most commonly used is paraxylene (p-xylene); however, any phenylene having substituent groups subject to oxidation to form carboxyl groups at the para positions of the phenylene can be used. For example, exemplary substituent groups on the phenylene can include, but are not limited to, methyl, ethyl, propyl, isopropyl, formyl, acetyl, and combinations thereof The substituents can be the same or different.

1000271 The solvent used in the oxidation reaction can vary, but generally comprises acetic acid, which may optionally contain water, The oxidation reaction can be conducted under any conditions wherein oxygen is available. For example, the reaction can be conducted in air, wherein the oxygen in air can serve as the oxidant, and/or in an environment enriched with pure oxygen (e.g., an all-oxygen atmosphere or an inert gas atmosphere to which some concentration of oxygen is added). A transition metal catalyst and, optionally, a co-catalyst, are commonly used. The oxidation catalyst can vary and can, in some embodiments, comprise a heavy metal salt or compound (e.g., a cobalt, manganese, iron, chromium, and/or nickel-containing compound or salt, or a combination thereof) as described, for example, in US. Patent No, 2,833,816 to Saffer et c.iL, which is incorporated herein by reference. Various co-catalysts and/or promoters can also be added, including, but not limited to, a bromine-containing compound, a bromide salt, a ketone (e.g., butanone, triacetylmethane, 2,3-pentanedione, methylethylketone, acetvlacetone, or a combination thereof), a metalloporphyrin, a zirconium salt, or a combination thereof 1000281 Oxidation is typically conducted at elevated temperature and/or elevated pressure.

Generally, the temperature and pressure must be sufficient to ensure that the oxidation reaction proceeds, but also to ensure that at least a portion of the solvent is maintained in liquid phase.

Therefore, it is generally necessary to conduct the oxidation reaction under both elevated temperature and elevated pressure conditions. The temperature required for the oxidation reaction may vary with the selection of the catalyst and optional co-catalyst and/or promoter. In certain embodiments, the reaction temperature is in the range of about 160°C to about 220 °C; however, in some embodiments, the temperature can be maintained below 160 °C while still obtaining the oxidized product.

1000291 Following the oxidation reaction, the reaction mixture is typically cooled (e.g., by transferring the mixture to one or more crystallizer units, with decreased pressure). The resulting mixture generally comprises a slurry from which the crude terephthalic acid can be isolated, The means for isolating the crude terephthalic acid can vary and may comprise filtration, centrifugation, and or any other suitable means for the separation of a solid phase and liquid phase. The solid phase is typically washed with fresh water and/or acetic acid to give isolated crystals of crude terephthalic acid, The liquid phase (typically comprising water, acetic acid, methyl acetate, and various other components) can, in some embodiments, be treated such that the acetic acid is separated from water and other low-boiling components. For example, in some embodiments, a portion of the liquid phase is vaporized and the vapor is sent to a distillation apparatus (e.g., wherein it can undergo azeotropic distillation). Generally, azeotropic distillation can be an effective method for separating acetic acid from water and is done in the presence of an organic entrainer. Typically, within an azeotropic distillation apparatus, a bottoms product will form, comprising primarily acetic acid (which can, in some embodiments, be recycled into the oxidation reaction), The tops product may comprise organic entrainer, water, and methyl acetate and can subsequently be cooled to form a condensate, 1000301 The crude terephthalic acid is then purified to provide PTA suitable for use in the production of poly(ethylene terephthalate), Various impurities are generally present in the crude terephthalic acid at this stage. For example, 4-carboxybenzaldehyde is one of the most common contaminants, as well as compounds that impart some degree of color to the crude terephthalic acid. Purification of the CTA typically requires at least one chemical transformation in addition to at least one physical procedure (e.g., crystallization, washing, etc.). The chemical transformation can include various processes, including but not limited to catalytic hydrotreatment, catalytic treatment, oxidation freathent, and/or recrystallization. Commercially, the most common'y used chemica' transformation is hydrogenation, which can transform one of the main impurities in the CIA, 4-carboxybenzaldehyde, to p-tciluic acid, which is easier to remove.

[00031] Various hydrogenation conditions can be used according to the invention. The CIA is generally dissolved in a solvent (e.g., water). In some embodiments, heat and/or pressure are required to dissolve the CTA in water. It is then subjected to hydrogenation in the presence of a Group VIII noble metal hydrogenation catalyst (e.g., a platinum, palladium, ruthenium, or rhodium catalyst) or an alternative type of catalyst (e.g., a nickel catalyst). The catalyst can be a homogeneous or heterogeneous catalyst and can be provided in an unsupported form or can be supported on any type of material suitable for this purpose. For example, the heterogeneous catalyst employed in the purification of the crude terephthalic acid product may be a supported nobel metal catalyst, including platinum and/or palladium on an inert carbon support. Support materials are generally porous materials including, but not limited to, activated carbon/charcoal, quartz powder, or a combination thereof. The hydrogen source is typically hydrogen gas, although this can vary as well. Although hydrogenation processes can, in certain cases, occur at atmospheric pressure and ambient temperature, on the commercial scale, heat and/or pressure are often applied. For example, in certain embodiments, the temperature is from about 200 °C to about 374 °C, e.g., about 250 °C or greater. The pressure is typically sufficient to maintain the CTA solution in liquid form (e.g., about 50 to about 100 atm). The amount of hydrogen required to effect hydrogenation of the CTA is typically an excess of that amount required for reduction of dissolved impurities. The hydrogenation can occur, for example, within a pressure vessel, hydrogenator, or plug-flow reactor or can be accomplished by flow hydrogenation, wherein the dissolved CTA is passed over a fixed bed catalyst in the presence of hydrogen. 11.

1000321 The purified terephthalic acid is recovered by one or more physical procedures. For example, PTA is generally obtained via crystallization of the product from solution (e.g., water), as a majority of the impurities, including p-toluic acid, acetic acid, and small amounts of terephthalic acid remain in the solution. Thus, the mixture in some embodiments is passed through one or more crystallizers and depressurized (which generally cools the mixture and evaporates some water, giving a slurry of PTA crystals), The PTA can be recovered by such means as filtration and/or centrifugation, washed, and dried to provide the pure desired material, The remaining solution is known as pure plant mother liquor (PPML). The temperature at which this separation of PTA and PPML is conducted can vary; however, it is typically in the range of from about 70 °C to about 160 °C (e.g., about 100 °C or greater).

1000331 Figure 1 discloses one aspect of the present process that treats the aqueous condensate liquor from a PET process in a PPMLSX and contamination removal system. Here, the aqueous condensate liquor stream Z from the PET process 300 is combined with the PPI\']IL stream Y from the pure plant process 1000 to form a combined stream X, The combined stream X is sent to a PPMLSX process 400 and contamination removal process 500, The reverse osmosis permeate stream, which is the resulting treated stream Q, can be sent to other downstream processes, or optionally, mixed with the crude terephthalic acid stream S in the slurry formation step in process 800. Optionally, as show in Figure 2, Stream Z can be sent directly to the PPMLSX process.

1000341 Figure 3 discloses another aspect of the present process that treats the aqueous condensate liquor from a PET process in a PPMILSX and contamination removal system. Here, the aqueous condensate liquor stream Z from the PET process 300 is combined with an azeotropic distillation column 600 overhead stream G to form a combined stream X2. The combined stream X2 is sent to a PPMLSX process 400 and contamination removal process 500.

Also sent to the PPIvILSX and contamination removal system is the PPML stream Y from the pure plant process 1000. The reverse osmosis peimeate stream, which is the resulting treated stream Q, can be sent to other downstream processes, or optionally, sent to be mixed with the crude terephthalic acid stream 5 in the the slurry formation step in process 800.

1000351 Figure 4 discloses yet a further aspect of the present process that treats the aqueous condensate liquor from a PET process in a PPMILSX and contamination removal system. Here, the aqueous condensate liquor stream Z from the PET process 300 is sent directly to the PPMLSX process without the PPML stream from the pure plant process 1000. Stream Z is treated in process units 400 and 500. The reverse osmosis permeate stream, which is the resulting treated stream Q, can be sent to other downstream processes, or optionally, sent to be mixed with the crude terephthalic acid stream 5 in the the slurry formation step in process 800.

1000361 In each of the above figures, the organic rich stream S from the PPMLSX process 400 is sent to an azeotropic distillation column 600 for removal of the high boiling organics. Also sent to the azeotropic distillation column are the oxidation reactor 700 overheads I. Here, the bottom fraction of the azeotropic distillation column 600 is sent to the oxidation reactor 700.

The bottom fraction would contain some of the volatile organics from the PET aqueous condensate liquor, as well as acetic acid. The amount of the bottom fraction sent to the oxidation reactor can vary from 50% to 100%, including 60%, 70%, 80%, and 90%.

1000371 In the processes described above, the portion of the aqueous condensate liquor from the polyester plant sent to the pure plant mother liquor solvent extraction process can vary from 10% and 90%, including 20%, 30%, 40%, 50%, 60%, 70%, and 80%. The amount sent will depend on the overall plant design, process efficiencies, and amount of RO permeate stream needed for other parts of the plant. Further, the RO permeate stream can be divided into several slip streams, with each stream feeding a different part of the integrated plant. For example, a first portion of the RO permeate stream can be combined with a crude terephthalic acid stream prior to introducing into a terephthalic acid purification plant, and a second portion be recycled back to the polyester plant. Or, a first portion of the RO permeate stream can be combined with a crude terephthalic acid stream prior to introducing into a terephthalic acid purification plant, and a second portion discharged into a waste water stream.

1000381 Figure 5 discloses the details of the PPMLSX process 400. "OR" represents an oxidation reaction of paraxylene, such as generally described above, Other discussion of such reactions is provided, for example, in U.S. Patent Nos. 5,705,682 to Ohkashi e/ aL; and 6,143,926 and 6,150,553 to Parten, each of which is incorporated herein by reference. Stream B represents the overhead condensates formed during the oxidation reaction as well as the liquid and vapor phases obtained following the oxidation reaction and removal of the solid crude terephthalic acid, As such, stream B primarily comprises water and acetic acid (in liquid and/or vapor form). The primary component is generally acetic acid (e.g., at least about 50% by volume) and the remainder of the stream is generally water, although small amounts (e.g., less than about 5%, less than about 2%) of organic components (e.g., methyl acetate) can also be present in stream B. The liquid and/or vapor-containing stream B is brought into contact with an organic entrainer in distillation column 30. The entrainer can valy, but is advantageously a substance suitable for azeotropic distillation of a mixed solution of acetic acid and water. For example, in certain embodiments, the entrainer comprises toluene, xylene, ethylbenzene, methyl butyl ketone, chlorobenzene, ethyl amyl ether, butyl formate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, amyl acetate, methyl acetate, n-butyl propionate, diisobutyl propionate, propanol, water, or a combination of any two or more of these or other entrainers.

Column 30 can be, for example, a trayed or packed column. A general discussion of azeotropic distillation processes to separate water from acetic acid is provided, for example, in U.S. Patent No. 5,980,696 to Parten et at, which is incorporated herein by reference.

1000391 Within column 30, organic entrainer is used to separate acetic acid and water. The acetic acid-containing phase can be removed from the bottom of the column as streams G and JI. Typically, stream G comprises about 95% acetic acid and about 5% water and does not contain a significant amount of entrainer. Stream C is recycled to the column 30 through reboiler 60. The hot acetic acid stream Ji leaving column 30 is passed through heat exchanger prior to passage back into the oxidation reaction, The organic stream Fl exiting the decanter is also passed through heat exchanger 25 such that heat from acetic acid stream JI is transferred to the organic stream Fl prior to its entry to the column 30 as stream F2. As such, organic stream F2 enters the column 30 at an increased temperature relative to the temperature upon exiting the decanter 20.

1000401 The vapor phase produced within column 30 generally comprises organic entrainer, as well as water and methyl acetate. Methyl acetate is advantageously removed from column 30 as it can, in some embodiments, interfere with the azeotropic separation within column 30, The vapor phase can be removed from the distillation column as stream C. This stream may be condensed within condenser 40 to provide condensate stream P. Condensate stream P generally comprises organic entrainer and may further comprise water, which can be removed from the mixture or maintained as a component of condensate stream P. The temperature of condensate stream P can van!; however, in exemplary embodiments, stream P is between about 60 °C and about 100 °C, such as between about 70 °C and about 90 °C, between about 75 CC and about 82 °C (e.g., about 78 °C or about 80 °C in certain embodiments), It is noted that the temperature of the condensate will vary somewhat depending upon the makeup of the condensate stream D (e.g., the specific entrainer used). Here, stream Z, Y, X, and X2 from Figures I -4 or a combination (herein after referred to as stream "A" for simplicity) is brought into contact with stream B in a mixer 10. The weight ratio of stream A to stream B can vary and other components can be added to the mixer if desired (e.g., additional entrainer or water). The ratio of stream P to stream A is about 1:1 to about 5:1 (e.g., about 1.7:1 to about 2.1:1). The nature of the mixer 10 can vary; it can comprise an extraction column, static mixer, dynamic mixer (e.g., an agitating mixer), pump, or shaker.

1000411 The resulting mixture of stream A and stream P exits the mixer 10 as mixed stream E and is passed into a decanter 20. The decanter can be any component which can provide for separation of an organic (e.g., entrainer-rich) stream Fl from an aqueous stream Ki.

Sometimes, a single decanter can be used, which can reduce the capital cost of the system and reduce the degree of hydrolysis of the entrainer. Also, certain organic impurities originally present in the PPML stream A (e.g., p-toluic acid, benzoic acid, etc.) are extracted into the organic phase and thus removed via organic stream Fl. Methy' acetate (originally present in stream C from distillation column 30) is partitioned into aqueous stream Ki.

1000421 The organic stream P2 is routed to the distillation column 30. Although the figures show entry of stream P2 at the middle of the distillation column, this is not intended to be limiting; stream F2 may enter the column at the top, middle, or bottom of the distillation column or at any stage in between. With the entry of certain organic components via stream P2, it is noted that the makeup of streams C and JI leaving the distillation column 30 can be affected.

Generally, the majority of the organic components that enter the distillation column via stream F2 are retained in the acetic acid phase and are removed from column 30 via stream 31.

1000431 Aqueous stream K! can be treated to allow water to be reused within the process (e.g., in the purification of CTA), recycled for other purposes, or disposed of as waste water. As shown in Figure 1, the heated effluent water LI exiting the recovery column 70 can be passed through the heat exchanger 65 in a heat exchange relationship with the aqueous stream KI exiting the decanter 20. As such the aqueous stream K2 exiting the heat exchanger 65 can be delivered to the column 70 at a significantly increased temperature. The temperature of stream K2 can vary such that stream K2 can comprise an aqueous liquid and/or vapor phase. Provision of stream K2 at the increased temperature is beneficial in that the quantity of steam (via stream M) that must be introduced into column 70 to effectively strip the organic components can be significantly reduced. Undesirable methyl acetate and/or acetaldehyde, which can be present in aqueous stream 1(2 can be stripped from the aqueous phase of the PPML extraction in certain embodiments by passing the aqueous phase K2 through recovery column 70, which is designed to strip out any residual organic material. It is noted that a small amount of the organic phase (e.g., comprising the organic entrainer) can also be present in stream 1(2 and in some embodiments, such residual organic material can also be removed via recovery column 70.

Generally, the stripping of organic material from the aqueous phase is accomplished via contacting the aqueous phase stream 1(2 with steam, shown as stream M entering the column 70.

Alternatively, a reboiler on column 70 can be used in place of stream 14, In order to effectively strip the organic components, the stream to be treated generally shouki be heated to about 40 °C to about 140 °C, including 60°C to 100 °C, e.g., about 95 °C. Cleaned water can exit the column, e.g., at the bottom thereof, via stream L2. Recovery column 70 can be further equipped with a condenser 50, which returns a reflux to the top of the column with a vapor purge and a liquid product.

1000441 Figure 7 discloses the details of the PPMLSX process 400. "OR" represents an oxidation reaction of paraxylene, such as generally described above. Figure 7 differs from figure only by the inclusion of an optional additional small stripping column 35, which is fed with a sidestream from column 30 and removes a proportion of some compounds/azeotropic compositions of intermediate boiling points from column 30, such as paraxylene which are purged from the striper column bottoms stream (labelled "STRTPBOT"). This stream is ultimately fed to the oxidation reactor (OR).

1000451 Table 1 shows the percentage of components retained in the water phase from a water/propyl acetate extraction experiment. The data was obtained by contacting I 00 grams of water, containing 1000 ppm (weight/weight basis) of the minor component, with 100 grams of propyl acetate at 70°C. The water phase was then sampled at intervals of 1, 5, 10 and 30 minutes after initial contact, to confirm that equilibrium partition between water and organic phases had been achieved.

Component Time of % remaining Sample -in Water Minutes Phase Ethylene Glycol 1 82.8 914 83.6 75.6 1,4 Dioxane I 34.7 32.8 33.9 33.7 2 methyl-1,3-dioxolane 5 28.3 28,4 27.9 Acetaldehyde 1 20.7 19.3 18.4 17.4

Table 1

1000461 The behavior of the minor impurity components acetaldehyde, 3-methyl-1,2-dioxolane, 1,4-dioxane and ethylene glycol for the configuration given in Figure 7 are shown in Table 2, which gives the percentage of each component that is purged via each of the exit streams. As can be seen from Table 2, the majority of the minor impurity components that are introduced by the inclusion of the PET plant waste water in stream A, are passed out via stream L2.

Ethylene glycol is predominantly extracted into the water phase and the majority exits via stream L2. However, some ethylene glycol is partitioned into the organic phase and is passed via stream F I to column 30, from which it is purged via bottoms stream Ji.

1000481 Acetaldehyde, 3-methyl-i,2-dioxolane and I,4-dioxane, while being present in stream F!, are lighter boiling components and might also form azeotropic mixtures with various other components in column 30. A proportion of 1,4-dioxane exits via stream J 1. Only a small proportion of these components are purged via the optional stripping column 35. Therefore, the majority of these components are returned from column 30 to the extraction process via the overheads stream D from column 30 to the mixer 10. Thus, the majority of these components are found to be passed via stream Ki to the recovery column 70.

1000491 A proportion of volatile acetaldehyde is found to be removed from the top of the recovery column 70 and is purged via the liquid and vapor streams exiting from condenser 50.

1000501 The remainder of the components exit via stream L2.

OXi 09A BASEWAT MEAC2 N2VENT STRTPBOT -Ji -L2 Acetaldehyde 0,0 8i3 9.1 9,5 0.0 2methyl-1,3-1.4 98.5 0,0 0.0 0.1 dioxolane 1,4-Dioxane 15.0 84.7 0.0 0.0 0.3 Ethylene Glycol 29.4 70.2 0.0 0.0 0.4

Table 2,

1000511 Components exiting via streams JI and STRTPBOT will pass to the oxidation reactor (OR), Components exiting the streams N2VENT and MEAC2 from the top of column 70 will be processed via the conventional offgas systems and methyl acetate recovery systems elsewhere in the TA production process. The components exiting in stream L2 will be fed forward to the filtration and reverse osmosis system.

1000521 Figure 6 discloses the contamination removal process 500. Here, stream L2 contains impurities (e.g. carboxylic acids, metals) that make it unsuitable for use in other parts of the PTA plant. Further, because the operating temperature of the PPMLSX process and poor rejection of acetic acid at these temperatures, fouling and scaling of reverse osmosis membranes may occur.

Surprisingly, it has been found that pre-treatment of stream L2 followed by reverse osmosis results in a demineralized water stream that is suitable for use in other parts of the PTA plant.

Specifically, pre-treating L2 with an alkali solutions and micro or ultra-filtration makes reverse osmosis an economical and efficient method of obtaining demineralized water. Upon exiting the PPMLSX process, aqueous eluent stream L2, at a pH of less than or equal to 7, including 2-7,4, 5, 6 and 7, has the following composition in Table 3:

Description Unit Typical Range

ACETIC AC1D ppm 1700 600-3000 TM ppm 106 50-450 CBA* ppm 3 0-20 P-TOLUIC ACffl* ppm 23 10-620 BENZOIC ACID* ppm 35 20-350 METhYL ACETATh ppm 50 10-200 PROPANOL ppm 37 10-200 PROPYL ACETATh ppm 0.1 0-1 COBALT ppm 1,0 0-10 MANGANESE ppm 1,0 0-10 BROMIDE ppm 4 0-20 SODIUM ppm 1 0-10 COD mg/L 2237 1000-4500 * Acid and salts of acid expressed as w/w concentration of the acid.

Table 3

100053] Prior to using L2 in a reverse osmosis process, L2 is treated to remove carboxylic acids and dissolved metals, and the pH is adjusted. Here, L2 enters neutralizer 100, wherein the aqueous stream is contacted with an alkali (e.g. sodium hydroxide, potassium hydroxide, calcium hydroxide, sodium carbonate, potassium carbonate, calcium carbonate, and mixtures thereof) to raise the pH to between 8-11, including 9 and 10. The concentration of the alkali in the aqueous stream can range from 5 wt.% to 90 wL%, including 5 wL% to 80 wt.%, 10 wt.% to 80 wt.%, 10 wt.% to 90 wt.%, 20 wt.% to 90 wt.%, 20 wt.% to 80 wt.%, 20 wt.% to 70 wt.%, 30 wt.% to 90 wt.%, 30 wt.% to 80 wt.%, 30 wt.% to 70 wt.%, and 30 wt.% to 60 wt.%. The concentration needs to be sufficient enough to reach a alkali concentration of 500 to 2000 ppm, Additionally, the dissolved and suspended carboxylic acids (e.g acetic acid, terephthalic acid, CBA, p-toulic acid, benzoic acid) are converted to their respective soluble salts, For example, if sodium hydroxide is used as the alkali, then acetic acid is coverted to sodium acetate. Additionally, the dissolved metals (e.g. cobalt, manganese) are converted to metal hydroxides and precipitate out in to the aqueous stream. Neutralizer 100 can be any device that results in sufficient contact between stream L2 and the alkali. For example, counter-current washer, gravity feed decanter (e.g. where L2 passes vertically through the alkali solution), static mixer, sparger can be used.

Below, in Table 4, is the composition of the pT-I adjusted stream N when sodium hydroxide is used as the alkali solution:

Description Unit Typical Range

ACETTC ACID* ppm 1660 600-3000 TA ppm 103 50-450 CBA* ppm 3 0-20 P-TOLIJIC ACD* ppm 22 102O BENZOIC ACW* ppm 34 20-350 METHYL ACETATE ppm 4 10-200 PROPANOL ppm 36 10-200 PROPYL ACETATE ppm 0.1 0-1 COBALT ppm 1 0-10 MANGANESE ppm 1 0-10 BROMIDE ppm 4 0-20 SODIUM ppm 662 500-1000 COD mg'L 2237 10004500 * Acid and salts of acid expressed as w/w concentration of the acid

Table 4

1000541 Next, the pH adjusted stream N is sent to a pre-filtration unit 120, or optionally a holding tank 110 prior to unit 120, for removal of suspended solids. Here, pH adjusted stream N is contacted with at least one pre-filtration membrane to remove the metal hydroxides to form treated stream P. For example, the pre-filtration membrane can be an ultrafiltration membrane KMS HFMTM-ISO with a pore size of around 0.1 micron has a rejection performance of >99.5% for cobalt and manganese hydroxides leaving a residual <0.05 ppm cobalt and manganese in the treated stream. Typical pre-filtration units include ultra-filtration, micro-filtration, and other media filtration that removes metal hydroxides and other potentially fouling solids prior to the RO step. Ultra-filtration or micro-filtration with a separation range of less than or equal to 0.1 micron including Ultra-filtration Elements such as KTVIS FIFM 180 can provide suitable protection of the reverse osmosis membrane, Below, in TableS, is the composition of the treated stream P when sodium hydroxide is used as the alkali solution:

Description Unit Typical Range

ACETIC ACD* ppm 1660 600-3000 TA* ppm 103 50-450 CBA ppm 3 0-20 P-TOLUIC ACID* ppm 22 10-620 BENZOIC ACID° ppm 34 20-350 METHYL ACETATE ppm 48 10-200 PROPANOL ppm 36 10-200 PROPYL ACETATE ppm 0.1 0-1 COBALT ppm <0.05 0-1 MANGANESE ppm <0.05 0-1 BROMIDE ppm 4 0-20 SODIUM ppm 662 500-1000 COD mg/L 2237 1000-4500 * Acid and salts of acid expressed as w/w concentration of the acid

Table 5

100055] Treated stream P next passes into reverses osmosis unit t30, where sodium, acetate, and other ionic species are removed, along with a pH reduction to between about 7-I 0, thereby creating a demineralized water stream Qi and Q. Optionally, a second reverse osmosis unit 140 can be employed with unit t30 to further reduce the concentration of sodium, acetate, and other ionic species. Here, the first pass permeate RI is fed into unit 140, and a demineralized stream Q2 is drawn off, Further, units 130 and 140 can be used in a loop type configuration, with a portion of the unit t40 permeate R2 being recycled back to unit 130. For example, treated stream P can pass through two reverse osmosis KMS Fluid Systems TFC-SW membranes can be arranged in series, resulting in a demineralized water stream Q with 0.97 ppm of sodium and 2.49 ppm of acetate, and pH of 6. Also, the present disclosure is not limited to one or two reverse osmosis units. Additional units can be employed in series or in loop type configurations with units 130 and 140 depending on application, size of plant, and location. Typical reverse osmosis units can include High Rejection Reverse Osmosis membranes, such as those used for sea water, brackish water, or waste water reclamation, including Fluid Systems®TFC®-SW, DOWfhFmMTECThfSW30HRLF400, FLUID SY5TEMS®TFC-FR, DOWThIFmMTEcThTBW30400, Fluid Systems®TFC®-HR. Below, in Table 6, is the composition of the demineralized water stream Q when sodium hydroxide is used as the alkali solution:

Description Unit Typical Range

SODIUM ppm 0.3 0,1-10 ACETATE ppm 1 0.5-10 MANGANESE ppm <0,05 0-1 POTASSIUM ppm <0,05 0-1 CALCIUM ppm <0,05 0-1 MAGNESIUM ppm <0,05 0-1 RON ppm <0.05 01 COBALT ppm <0.05 21.

Table 6

1000561 As shown in Table 6, the demineralized water stream Q is substantially free of metal compounds, Mn, K, Ca, Mg, Fe, and Co (i.e. a total metal concentration, excluding the alkali sodium, between 0.01 and 1 ppm, including between 0.01 ppm and 0.! ppm, and between 001 ppm and 0.05 ppm), while also having low sodium and acetate concentrations.

Claims

CLAIMSWhat we claim is: I. A process for treating aqueous condensate liquor from a polyester plant in an integrated terephthalic acid -polyester plant comprising: a. contacting at least a portion of the aqueous condensate liquor from a polyester plant with an aqueous mother liquor from a terephthalic acid purification plant process to form a combined stream; b. providing the combined stream to a pure plant mother liquor solvent extraction process to separate the combined stream into an aqueous stream and organic stream; c. contacting the aqueous stream with an alkali to form a pH adjusted stream; d. contacting the p1-I adjusted stream with a filter to form a treated stream; and e. contacting the treated stream with a reverse osmosis unit to form an RD permeate stream.
2. The process of claim 1, wherein the aqueous condensate liquor from the polyester plant comprises at least one compound selected from the group consisting of acetaldehyde, 2-methyl, 1,3-dioxolane, 1,4 dioxane, acetic acid, and monoethylene glycol.
3. The process of claim I, wherein the aqueous condensate liquor from the polyester plant comprises: 0 to 3 wt.% of acetaldehyde; 0 to 3 wt.% 2 methyl 1,3 dioxolane; 0 to 0.5 wt.% 1,4 dioxane; 0 to 2 wt.% monoethylene glycol and 0 to 1 wt% acetic acid.
4. The process of one of claims 1-3, wherein the RD permeate stream is recycled to the polyester plant or the terephthalic acid plant.
5. The process of one of claims 1-3, wherein the RD permeate stream is divided into several slip streams, wherein each slip stream goes to a different part of the combined terephthalic acid -polyester plant.
6. The process of claim 5 wherein the RD permeate stream is divided into a first slip stream and a second slip stream, wherein the first slip stream is contacted with a crude terephthalic acid stream, and the second slip stream sent to the polyester plant.
7. The process of one of claims 1-3, wherein a portion of the RD permeate stream is contacted with a crude terephthalic acid stream to form a second combined stream, and the second combined stream is sent to the terephthalic acid purification plant process.
8. The process of one of claims 1-3, wherein a portion of the RD permeate stream is sent to the polyester plant.
9. The process of one of claims 1-3, wherein the organic stream comprises volatile organic compounds selected from the group consisting acetic acid, acetaldehyde, 2 methyl 1,3 dioxolane, 1,4 dioxane, acetic acid, and monoethylene glycol,
10. The process of claim 9, wherein the organic stream is sent to an azeotropic distillation system, wherein the azeotropic distillation system produces a top fraction and bottom fraction, wherein the bottom fraction contains at least a portion of the volatile organic compounds.
Ii, The process of claim 10, wherein from 50% to 100% of the bottom fraction is sent to an oxidation reactor.
12. A process for treating aqueous condensate liquor from a polyester plant in an integrated terephthalic acid -polyester plant comprising: a. providing at least a portion of the aqueous condensate liquor from a polyester plant to a pure plant mother liquor solvent extraction process; b. providing an aqueous mother liquor from a terephthalic acid purification plant process to the pure plant mother liquor solvent extraction process; c. separating the condensate liquor and mother liquor streams into an aqueous stream and organic stream; d. contacting the aqueous stream with an alkali to form a pH adjusted stream; e. contacting the pT-I adjusted stream with a filter to form a treated stream; and f. contacting the treated stream with a reverse osmosis unit to form an RO permeate stream.

13, The process of claim 12, wherein the aqueous condensate liquor from the polyester plant comprises at least one compound selected from the group consisting of acetaldehyde, 2-methyl, 1,3-dioxolane, 1,4 dioxane, acetic acid, and monoethylene glycol.

14, The process of claim 12, wherein the aqueous condensate liquor from the polyester plant comprises: 0 to 3 wt.% of acetaldehyde; 0 to 3 wt.% 2 methyl 1,3 dioxolaiie; 0 to 0,5 wt.% 1,4 dioxane; 0 to 2 wt.% monoethylene glycol and 0 to 1 wt% acetic acid.

15, The process of one of claims 12-14, wherein the RO permeate stream is recycled to the terephthalic acid p'ant or the polyester plant, 16, The process of one of claims 12-14, wherein the RO permeate stream is divided into several slip streams, wherein each slip stream goes to a different part of combined terephthalic acid -polyester plant.17, The process of claim 16, wherein the RO permeate stream is divided into a first slip stream and a second slip stream, wherein the first slip stream is contacted with a crude terephthalic acid stream, and the second slip stream sent to the polyester plant.18. The process of one of claims 12-14, wherein a portion of the RO permeate stream is contacted with a crude terephthalic acid stream to form a second combined stream, and the second combined stream is sent to the terephthalic acid purification plant process.19, The process of one of claims 12-14, wherein a portion of the RO permeate stream is sent to the polyester plant.20. The process of one of claims 12-14, wherein the organic stream comprises volatile organic compounds selected from the group consisting acetic acid, acetaldehyde, 2 methyl 1,3 dioxolane, 1,4 dioxane, acetic acid, and monoethylene glycol.21 The process of claim 19, wherein the organic stream is sent to an azeotropic distillation system, wherein the azeotropic distillation system produces a top fraction and bottom fraction, wherein the bottom fraction contains at least a portion of the volatile organic compounds.22. The process of claim 20, wherein from 50% to 100% of the bottom fraction is sent to an oxidation reactor.23 A process for treating aqueous condensate liquor from a polyester plant in an integrated terephthalic acid -polyester plant comprising: a. contacting at least a portion of the aqueous condensate liquor from a polyester plant with an azeotropic distillation overhead gas stream to form a combined stream; b. providing the combined stream to a pure plant mother liquor solvent extraction process; c. providing an aqueous mother liquor stream from a terephthalic acid purification plant process to the pure plant mother liquor solvent extraction process; d. contacting the combined stream and mother liquor stream in the pure plant mother liquor solvent extraction process to form a second combined stream; e. separating the second combined stream into an aqueous stream and organic sfream, f, contacting the aqueous stream with an alkali to form a pH adjusted stream; g. contacting the p1-I adjusted stream with a filter to form a treated searn; and contacting the treated stream with a reverse osmosis unit to form a RO permeate stream.24. The process of claim 22, wherein the aqueous condensate liquor from the polyester plant comprises at least one compound selected from the group consisting of acetaldehyde, 2-methyl, 1,3-dioxolane, 1,4 dioxane, acetic acid, and monoethylene glycol, 25. The process of claim 22, wherein the aqueous condensate liquor from the polyester plant comprises: : 0 to 3 wt% of acetaldehyde; 0 to 3 wt% 2 methyl 1,3 dioxolane; 0 to 0.5 wt.% 1,4 dioxane; 0 to 2 wt% monoethylene glycol and 0 to I wt% acetic acid.26. The process of one of claims 23-25, wherein the RO penneate stream is recycled to the terephthalic acid plant or the polyester plant.27. The process of one of claims 23-25, wherein the RO permeate stream is divided into several slip streams, wherein each slip stream goes to a different part of combined terephthalic acid -polyester plant 28. The process of claim 27, wherein the RO permeate stream is divided into a first slip stream and a second slip stream, wherein the first slip stream is contacted with a crude terephthalic acid stream, and the second slip stream sent to the polyester plant 29. The process of one of claims 23-25, wherein a portion of the RO permeate stream is contacted with a crude terephthalic acid stream to form a second combined stream, and the second combined stream is sent to the terephthalic acid purification plant process.30. The process of one of claims 23-25, wherein a portion of the RO permeate stream is sent to the polyester plant.31. The process of one of claims 23-25, wherein the organic stream comprises volatile organic compounds selected from the group consisting acetic acid, acetaldehyde, 2 methyl 1,3 dioxolane, 1,4 dioxane, acetic acid, and monoethylene glycol.32. The process of claim 31, wherein the organic stream is sent to an azeotropic distillation system, wherein the azeotropic distillation system produces a top fraction and bottom fraction, wherein the bottom fraction contains at least a portion of the volatile organic compounds.33. The process of claim 32, wherein from 50% to 100% of the bottom fraction is sent to an oxidation reactor.34. A process for treating aqueous condensate liquor from a polyester plant in an integrated terephthalic acid -polyester plant comprising: a. providing at least a portion of the aqueous condensate liquor from a polyester plant to a pure plant mother liquor solvent extraction process; b. separating the condensate liquor into an aqueous stream and organic stream; c. contacting the aqueous stream with an alkali to form a p11 adjusted stream; d. contacting the pH adjusted stream with a filter to form a treated stream; and e. contacting the treated stream with a reverse osmosis unit to form a RO permeate stream, 35. The process of claim 32, wherein the aqueous condensate liquor from the polyester plant comprises at least one compound selected from the group consisting of acetaldehyde, 2-methyl, 1,3-dioxolane, 1,4 dioxane, acetic acid, and monoethylene glycol.36. The process of claim 32, wherein the aqueous condensate liquor from the polyester plant comprises: : 0 to 3 wt.% of acetaldehyde; 0 to 3 wt.% 2 methyl 1,3 dioxolane; 0 to 0.5 wt.% 1,4 dioxane; 0 to 2 wt.% monoethylene glycol and 0 to I wt% acetic acid, 37. The process of one of claims 34-36, wherein the RO permeate stream is recycled to the terephthalic acid plant or the polyester plant.38. The process of one of claims 34-36, wherein the RO permeate stream is divided into several slip streams, wherein each slip stream goes to a different part of combined terephthalic acid -polyester plant.39, The process of claim 38, wherein the RO permeate stream is divided into a first slip stream and a second slip stream, wherein the first slip stream is contacted with a crude terephthalic acid stream, and the second slip stream sent to the polyester plant.40. The process of one of claims 34-36, wherein a portion oftheRO permeate stream is contacted with a crude terephthalic acid stream to form a second combined stream, and the second combined stream is sent to the terephthalic acid purification plant process.41. The process of one of claims 34-36, wherein a portion of theRO permeate stream is sent to the polyester plant.42. The process of one of claims 34-36, wherein the organic stream comprises volatile organic compounds selected from the group consisting acetic acid, acetaldehyde, 2 methyl 1,3 dioxolane, 1,4 dioxane, acetic acid, and monoethylene glycol.43. The process of claim 42, wherein the organic stream is sent to an azeotropic distillation system, wherein the azeotropic distillation system produces a top fraction and bottom fraction, wherein the bottom fraction contains at least a portion of the volatile organic compounds.44. The process of claim 43, wherein from 50% to 100% of the bottom fraction is sent to an oxidation reactor.