Process for purifying a hydrogen halide solution containing organic impurities

Abstract

The present disclosure relates to a novel plant process for purifying hydrogen halide solutions. The process involves halogenating organic compounds, particularly phenolic compounds, in a hydrogen halide solution to precipitate halogenated compounds. The halogenated compounds may be filtrates, and the hydrogen halide solution may be further purified in an adsorbent bed, and the clean hydrogen halide solution may be recycled or used in other processes.

Description

[Technical field]

[0001] Various embodiments of the present disclosure relate generally to a process for removing organic impurities, particularly phenolic impurities, from hydrogen halide solutions, which is particularly useful for post-halogenation by-product streams. [Background technology]

[0002] Among industrial processes, the halogen oxidation (or oxidative halogenation) of organic compounds produces a significant number of commercial products. For example, brominated flame retardants such as tetrabromobisphenol A (TBBPA) are prepared by brominating organic substrates, e.g., bisphenols, to produce TBBPA. The products of the bromination include the valuable flame retardant, but also typically include an aqueous by-product stream containing HBr and impurities. In chlorine oxidation, the aqueous by-product stream is also a challenge to address.

[0003] Commercially competitive industrial processes require that by-product streams be utilized or disposed of in an economical manner. This may include recycling the stream back into the process, diverting the stream to another process, or converting the stream into a separate commercial product. In the absence of these options, disposal may be necessary, but simply disposing of industrial streams is environmentally difficult and commercially ineffective as it would waste atomic value from the process. Thus, while recycling the stream back into the process, diverting the stream to another process, or converting the stream into a separate commercial product is highly desirable, overcoming the impurity characteristics of the by-product streams presents a significant hurdle to overcome. Summary of the Invention

[0004] Various embodiments of the present disclosure relate generally to processes for treating hydrogen halide streams having phenolic residuals.

[0005] An embodiment of the disclosure may be a process for treating an HX stream by oxidative halogenation or treating a stream with a halogen to halogenate the phenolic residual and produce a halogenated phenolic residual and a halogenated solution. The halogenated solution may be cooled and filtered to remove the halogenated phenolic residual from the halogenated solution and produce a partially purified HX stream. The process may include the further step of passing the partially purified HX stream through an adsorbent bed to produce a purified HX stream.

[0006] In some embodiments, the HX stream comprises an HCl stream, an HBr stream, an HI stream, or a combination thereof. In some embodiments, the HX stream comprises an HCl or HBr stream, or an HBr stream. The HX stream can be less than about 30 wt% HX, less than about 20 wt% HX, less than about 15 wt% HX, or less than about 12 wt% HX.

[0007] In some embodiments, the HX stream may contain less than about 5 wt.% phenolic residuals, less than about 3 wt.% phenolic residuals, or less than about 1 wt.% phenolic residuals.

[0008] In one embodiment, the HX stream, the partially purified HX stream, and the purified HX stream each contain HBr.

[0009] In some embodiments, the oxidative halogenation is oxidative bromination and is a halogen of bromine.

[0010] In some embodiments, the oxidative halogenation is carried out at about 60°C or higher, 80°C or higher, or 90°C or higher.

[0011] In some embodiments, the reactants after oxidative halogenation are cooled to about 60° C. or below, or the reactants are cooled to about 40° C. or below. In some embodiments, the reactants are cooled to a temperature at least about 20° C. below the oxidative halogenation temperature.

[0012] In some embodiments, the ratio of halogen to phenolic residue is about 2:1 to 20:1 weight / weight, or the ratio of halogen to phenolic residue is about 8:1 to 12:1 weight / weight. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Although preferred embodiments of the present disclosure are described in detail, it will be understood that other embodiments are contemplated. Accordingly, the present disclosure is not intended to be limited in scope to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The present disclosure is capable of other embodiments and of being practiced or carried out in various ways. Also, in describing preferred embodiments, specific terminology is used for the sake of clarity.

[0014] It must also be noted that as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0015] Furthermore, to describe the preferred embodiments, terminology is used for the sake of clarity, and each term is intended to have the broadest meaning as understood by one of ordinary skill in the art and to include all technical equivalents that operate in a similar manner to accomplish a similar purpose.

[0016] Ranges can be expressed herein as from "about" or "approximately" one particular value and / or to "about" or "approximately" another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value.

[0017] "Comprising" or "comprising" or "including" means that at least the named compounds, elements, particles, or method steps are present in a composition, or article, or method, but does not exclude the presence of other compounds, materials, particles, or method steps, even if such other compounds, materials, particles, or method steps have the same function as the named one.

[0018] It should also be understood that a reference to one or more method steps does not exclude the presence of additional explicitly identified or intervening method steps between those steps. Similarly, it should also be understood that a reference to one or more components in a device or system does not exclude the presence of additional explicitly identified or intervening components between those components.

[0019] This disclosure was developed as part of a plant process development program. Bromine oxidation of organic compounds (i.e., electrophilic substitution of bromine on an aromatic ring) produces hydrobromic acid, also known as hydrogen bromide, which must be utilized or disposed of. However, HBr streams present many challenges. In particular, phenolic compounds from some processes can make by-product streams difficult to utilize and / or handle. Attempts to recover bromine value from HBr are difficult due to the presence of organic impurities. One common option in any plant process is to recycle the stream into the process or related processes, or convert the stream into another product. However, recycling the raw HBr stream can result in the production of undesirable by-products, which can lead to several issues, including but not limited to reduced purity of the final product, or precipitation of solids in the equipment and / or plugging of the equipment.

[0020] As part of this plant process development program, a process has been developed that removes most of the organic impurities, especially the phenolic impurities dissolved in HBr. It has been found that the organic impurities in the TBBPA by-product stream can be removed by reacting with bromine and / or chlorine to convert the soluble impurities to largely less soluble halogenated compounds that can be precipitated. Removal of the solids by filtration results in HBr with substantially reduced levels of brominated impurities in solution. If necessary, these brominated impurities can be further reduced by passing through a carbon or resin bed. The reaction with bromine can be carried out with a 2-20 fold excess of bromine, preferably 10 fold, to ensure complete bromination of all of the phenolic impurities. Higher bromination temperatures are preferred to reduce reaction times. Reaction temperatures above 60°C, preferably above 90°C, are recommended. The HBr solution purified by this method can be reused to recover bromine value or used for other applications. In particular, other processes that rely on halogen oxidation can be similarly purified using this method.

[0021] Thus, the present disclosure includes a process for purifying an HX stream containing phenolic residuals. The process may include treating the HX stream by oxidative halogenation to halogenate the phenolic residuals, thereby producing a halogenated phenolic residual and a halogenated solution. The halogenated solution may be cooled and filtered to remove the halogenated phenolic residuals and produce a partially purified HX stream.

[0022] The HX stream may be referred to as a stream or solution containing hydrogen halides, also called hydrogen halides. The term hydrogen halides includes halogen acids, such as hydrochloric, hydrobromic, and hydroiodic acids, i.e., HCl, HBr, and HI. The compounds may also be referred to as hydrogen chloride, hydrogen bromide, and hydrogen iodide. Hydrogen halides may be abbreviated as HX, where X is a fully recognized halogen, i.e., Cl, Br, or I. The hydrogen halide solution may include an HCl solution or an HBr solution, or the hydrogen halide solution may include an HBr solution. In some embodiments, the HX stream, the partially purified HX stream, and the purified HX stream may each independently include HBr. The hydrogen halide solution or HX solution may include an aqueous solution. The hydrogen halide solution or HX solution may include partially halogenated organic compounds or may include organic compounds resulting from a prior halogenation reaction.

[0023] The partially purified HX stream may be further processed. This processing may include passing the partially purified HX stream through an adsorbent bed to produce a purified HX stream. The adsorbent bed may be any adsorbent material used in industrial applications of acidic media to remove organic compounds from aqueous streams. The adsorbent bed may include a carbon bed (e.g., an activated carbon bed) or a neutral resin bed, such as a polystyrene bed, a polydivinylbenzene bed, or other polyaromatic resins.

[0024] The HX stream may generally contain less than about 5 wt. % phenolic residuals, less than about 1 wt. % phenolic residuals, or less than about 0.5 wt. % phenolic residuals. The phenolic residuals may include aromatic or pseudoaromatic structures (such as quinone moieties) that are susceptible to electrophilic substitution by halogens. The phenolic residuals may include monobromophenols, dibromophenols, tribromophenols, and other phenolic and / or aromatic or pseudoaromatic products. The phenolic residuals may be a by-product of the bromination of bisphenol A (IUPAC name: 4,4′-(propane-2,2-diyl)diphenol).

[0025] The HX stream may be less than about 50 wt% HX, less than about 40 wt% HX, or less than about 30 wt% HX. The process may be used on HX streams that have been reduced or diluted by prior chemical processes. Thus, the HX stream may preferably be less than about 20 wt% HX, less than about 15 wt% HX, or less than about 12 wt% HX.

[0026] The oxidative halogenation of the initial HX stream may be carried out at or above any temperature at which electrophilic substitution can occur. Oxidative halogenation may be carried out at or above 25°C, 60°C, 70°C, 80°C, or 90°C. Oxidative halogenation may be carried out at higher temperatures, but is generally limited by the pressure of the reaction medium. Oxidative halogenation may be carried out as high as 200°C in dedicated equipment, but higher temperatures are generally considered unsafe.

[0027] The oxidative halogenation of the initial HX stream can be carried out with any halogen capable of undergoing electrophilic substitution on the phenolic residues. Oxidative halogenation or halogen oxidation generally refers to treating the solution with a halogen at a temperature such that the organic material in the solution is halogenated, thereby producing a halogenated carbon bond and a hydrogen halide. Oxidative halogenation can be carried out with bromine (e.g., oxidative bromination) or with chlorine (e.g., oxidative chlorination). Oxidative halogenation can also be carried out with a combination of chlorine and bromine. Oxidative halogenation, such as the conversion of HBr to bromine by the addition of chlorine or the conversion of HBr to bromine by the addition of hydrogen peroxide, can be carried out with a halogen that can be added to the HX stream or can be generated in situ. The halogen in the HX solution need not be the same as the halogen in the oxidative halogenation. In one embodiment, the HX can be HBr and the halogen source can be bromine. In another embodiment, HX can be HBr, the halogen source can be chlorine where some of the chlorine reacts with HBr to produce bromine and HCl, and the oxidative halogenation can be a mixture of chlorination and bromination. Preferably, the oxidative halogenation is oxidative bromination.

[0028] The oxidative halogenation of the initial HX stream may be carried out at a ratio of halogen to phenolic residual such that the phenolic residual is effectively halogenated. The ratio of halogen to phenolic residual may be from about 2:1 to about 20:1 wt / wt, preferably from about 8:1 to about 12:1 wt / wt.

[0029] After oxidative halogenation, the halogenated solution may be cooled and then filtered. The halogenated solution may be cooled to a temperature at least about 10° C. below the temperature of halogenation, at least about 20° C. below the temperature of halogenation, or at least about 30° C. below the temperature of halogenation. The halogenated solution may be cooled to less than 60° C., less than about 50° C., or less than about 40° C. Cooling can be accomplished by any technique used in the manufacturing process. In one embodiment, cooling can be accomplished by removing residual halogen, for example, removing residual bromine from the halogenated solution.

[0030] The partially purified HX stream and the purified HX stream can be used in other process reactions. For example, the partially purified HBr stream can be subjected to chlorination to produce bromine, which can be removed from solution and used in other bromination reactions, thereby recovering valuable bromine value. Similarly, the purified HX stream can be treated with chlorine to produce bromine.

[0031] An embodiment of the disclosure may be a process for purifying an HX stream containing less than about 1 wt% phenolic residuals, where an HX stream having about 15 wt% or less HX is treated with bromine or chlorine as the halogen at above 60° C. to halogenate the phenolic residuals to produce a halogenated solution. The halogenated solution may be cooled to below 60° C. and filtered to produce a partially purified HX stream. The partially purified HX stream may be further processed by passing it through an adsorbent bed.

[0032] An embodiment of the present disclosure may be a process for purifying an HBr stream containing about 1 wt% or less phenolic residuals, where an HBr stream having about 15 wt% or less HBr is treated with bromine as the halogen at above 60° C. to brominate the phenolic residuals and produce a halogenated solution. The halogenated solution may be cooled to below 60° C. and filtered to produce a partially purified HBr stream. The partially purified HBr stream may be further processed by passing it through an adsorbent bed.

[0033] An embodiment of the disclosure may be a process for purifying an HBr stream containing about 1 wt% or less phenolic residuals, where an HBr stream having about 15 wt% or less HBr is treated with chlorine as the halogen at about 80° C. or greater to halogenate the phenolic residuals and produce a halogenated solution. The halogenated solution may be cooled to about 60° C. or less and filtered to produce a partially purified HX stream. The partially purified HX stream may be further processed by passing it through an adsorbent bed.

[0034] An embodiment of the disclosure may be a process for purifying an HBr stream containing about 1 wt% or less phenolic residuals, where an HBr stream having about 15 wt% or less HBr is treated with bromine as the halogen at about 90° C. or greater to halogenate the phenolic residuals and produce a halogenated solution. The halogenated solution may be cooled to about 60° C. or less and filtered to produce a partially purified HBr stream. The partially purified HBr stream may be further processed by passing it through an adsorbent bed.

[0035] An embodiment of the disclosure may be a process for purifying an HBr stream containing about 1 wt% or less phenolic residuals, where an HBr stream having about 15 wt% or less HBr is treated with bromine as the halogen at about 90° C. or greater to halogenate the phenolic residuals and produce a halogenated solution. The halogenated solution may be cooled to about 40° C. or less and filtered to produce a partially purified HBr stream. The partially purified HBr stream may be further processed by passing it through an adsorbent bed. EXAMPLES

[0036] Example 1 A three-necked 20 L reactor was equipped with a mechanical stirrer, condenser, and thermowell. The process effluent stream was a 10% HBr solution containing 306 ppm of phenolic impurities. A liquid chromatography (LC) method was used to measure the phenolic impurities. The HBr solution (16 kg) was charged to a reactor and stirred. It was heated to 95° C. with an electric mantle. When the temperature of the solution exceeded 50° C., 160 g of bromine was added and heating was continued. The mixture was heated at 95° C. for 30 minutes, after which the heat was turned off and the condenser was switched from reflux to distillation. A vacuum pump was connected via two ice-cold traps containing dilute sodium sulfite solution. The mixture was gradually cooled to 60° C. by removing unreacted bromine and some water under vacuum. It was then allowed to cool to ambient at atmospheric pressure. It was then filtered using a medium fritted glass funnel to remove precipitated solids. LC analysis of the filtered HBr solution showed only 26 ppm of phenolic impurities. It was passed through a column of styrene resin, and LC analysis showed that the HBr solution contained 0 ppm phenolic impurities.

[0037] Example 2 A 500 mL thick-walled glass reactor with ace fittings was fitted with a Teflon overhead with a thermowell, monometer, and stopcock, which was connected through a condenser to a receiver flask. The receiver flask was connected to a vacuum line through another condenser and trap. 300 g of waste stream HBr, containing approximately 500 ppm of phenolic impurities, was charged to the reactor. It was rapidly heated with an electric mantle while being magnetically stirred. When the temperature of the mixture reached 50°C, 3 g of bromine was added and the reactor was sealed. In approximately 15 minutes, the temperature of the mixture reached 120°C and the reactor pressure was approximately 25 psi. After the mixture was stirred at this temperature for 25 minutes, the electric mantle was lowered and the pressure was released by carefully opening the overhead stopcock. The liquid that distilled off was collected in a receiver. A vacuum was slowly applied to reduce the temperature of the mixture to 60°C; typically, a vacuum of 120-130 mmHg was required to reach 60°C. The mixture was filtered at 60° C. and the hot HBr solution contained only 63 ppm of phenolic impurities.

[0038] Example 3 Each 800 g HBr sample (3-1A and 3-2A) was treated with 80 g bromine (i.e., 10 wt %) and heated to 55° C. and 80° C., respectively, and held for 30 minutes. The mixtures were filtered hot at the end of the holding period and samples were taken for GC analysis. The results are shown in Table 1.

[0039] The resulting solutions were allowed to stand and cool to room temperature for approximately 4 hours. The solutions were filtered again before proceeding. A 400 g portion of each mixture (3-1B and 3-2B) was then chlorinated at 80° C., noting the formation of additional solids.

[0040] In a similar manner, two solutions of HBr (3-3 and 3-4) were treated with 1 wt % bromine, heated to 55° C. and 80° C., held for 30 min, filtered hot, and sampled for GC analysis, then allowed to cool to room temperature and filtered again. [Table 1]

[0041] Example 4 The HBr sample was filtered to remove solids and a sample was taken for analysis (4-0).

[0042] For 4-1A, a 3083 g sample of HBr was charged to a 5 L flask and heated to 80° C. Approximately 1 wt % (30 g) of bromine was carefully added below the surface. The solution was mixed with a large stir bar for approximately 3 hours. The mixture was then filtered while still hot and the isolated solids were washed with DI water. The hot solution was then divided into three equal parts. One portion (4-1B) was left to stand overnight. The second portion (4-1C) was treated with enough solid sodium sulfite to react to remove the bromine, sampled for analysis, and allowed to stand overnight. The third portion (4-1D), 996 g, was charged to a 1 L flask and heated to 80° C. and 33 g of chlorine (enough to convert at least 75% of the HBr number) was added over approximately 5 minutes. The reaction was stirred for 30 minutes and filtered hot.

[0043] For sample 4-2, a 950 g HBr sample was charged to a 1 L flask and heated to 80° C., followed by the addition of 5 g bromine. The mixture was stirred for 3 hours, filtered hot, and then sampled for analysis.

[0044] Sample 4-3 was treated exactly the same as sample 4-2, except that it was heated to 95°C. [Table 2-1] [Table 2-2]

[0045] Example 5 The HBr sample was filtered to remove solids and a sample was taken for analysis (Sample 5-0).

[0046] For sample number 5-1, 863.9 g of HBr sample was charged to a 1 L 4-neck round bottom flask. The mixture was heated to about 30° C. and about 26 g of Cl was added. 2 was added over a period of approximately 15 minutes. The reaction temperature was allowed to rise to approximately 40° C. during the addition. The mixture was sampled at the 15 minute hold time (samples were filtered before analysis). At the 30 minute hold time, the experiment was stopped and the remaining mixture was filtered. Portions of the sample were treated with enough solid sodium sulfite to remove any remaining bromine in solution before being fully analyzed.

[0047] After standing at room temperature for approximately 6 hours, solids were observed and the solution was filtered. After standing for a total of approximately 16 hours, additional solids were observed to have formed, so the solution was filtered again.

[0048] For sample number 5-2, 866 g of HBr sample was charged to the apparatus. The mixture was heated to about 60° C. and about 26 g of Cl was added. 2 was added over a period of approximately 15 minutes. After a hold time of 30 minutes the experiment was stopped and the mixture was filtered while still hot. The solution was allowed to stand overnight at room temperature and filtered again. The final solution was sampled for analysis.

[0049] For sample number 5-3, 878 g of HBr sample was charged to the apparatus. The mixture was heated to about 80° C. and about 26 g of Cl was added. 2 was added over a period of approximately 15 minutes. After a hold time of 30 minutes the experiment was stopped and the mixture was filtered while still hot. The solution was allowed to stand overnight at room temperature and filtered again. The final solution was sampled for analysis.

[0050] For sample number 5-4, 878 g of HBr sample was charged to the apparatus. The mixture was heated to about 100° C. and about 26 g of Cl was added. 2was added over a period of approximately 15 minutes. The reaction temperature was allowed to drop to approximately 96°C during the addition. After a hold time of 30 minutes the experiment was stopped and the mixture was filtered while still hot. The solution was allowed to stand overnight at room temperature and filtered again. The final solution was also sampled for analysis. No solids were isolated when filtered hot. A solid was observed to crystallize as the solution cooled.

[0051] For sample no. 5-5, 874 g of HBr sample was charged to the apparatus. The mixture was heated to approximately 80° C. Excess bromine was added subsurface until the solution was saturated. The experiment was stopped at a hold time of 30 minutes and the mixture was filtered while still hot. The solution was allowed to stand overnight at room temperature, but very little solids formed and was not filtered again after the overnight stand. It appears that the bromine-only process produces less soluble solids than those produced by the chlorination route. [Table 3]

[0052] Example 6 Approximately 8% HBr solution was filtered and analyzed as sample 6-0. Three 400 g portions of this 8% HBr solution were added with 0.53 g, 0.843 g, and 1.652 g of granular activated carbon. Carbon dioxide (Norit GAC 1240) was added and the solution was stirred for 4 hours at room temperature. All four samples were filtered through a 0.45 micron Whatman Autovial syringeless filter to remove carbon fines and analyzed. The data are reported in Table 4. [Table 4]

[0053] Example 7 A 50 mm ID column was packed with 139.3 g of granular activated carbon (Norit GAC 1240) to give a bed volume of approximately 280 mL. The HBr solution containing the phenols was pumped through the bottom of the column in an upward feed configuration at 5 mL / min. Thus, the residence time was less than 1 hour. Sample collection began at 1 hour into the feed. Multiple samples were analyzed for APHA color, while a single sample (sample 7-1) taken at approximately 2.5 hours was analyzed in full. Data for APHA color data is presented in Table 5, and for the analysis of the starting material and the sample taken at 2.5 hours, in Table 6. [Table 5] [Table 6]

[0054] Example 7 A jacketed column of 11 mm diameter was packed with 15 g of styrene-based adsorbent resin. A water-containing circulator was used to maintain the temperature at 60° C. The HBr solution containing phenols was pre-reacted with bromine, flash cooled, then filtered, and then pumped through the adsorbent bed at a controlled rate via a peristaltic pump. The starting concentration of phenols in the HBr is reported along with the concentration of phenols in the total volume of HBr passed through the column. The concentration of phenols is determined by HPLC analysis. The data is reported in Table 7. [Table 7]

[0055] Embodiment Additionally or alternatively, the present disclosure can include one or more of the following embodiments.

[0056] Embodiment 1. A process for purifying an HX stream containing a phenolic residue comprising treating the HX stream by oxidative halogenation to halogenate the phenolic residue to produce a halogenated phenolic residue and a halogenated solution; cooling the halogenated solution; and separating the halogenated phenolic residue from the halogenated solution. and filtering the crude oil residue to produce a partially purified HX stream.

[0057] Embodiment 2. A process for purifying a HX stream containing a phenolic residual comprising treating the HX stream by oxidative halogenation to halogenate the phenolic residual to produce a halogenated phenolic residual and a halogenated solution, cooling the halogenated solution, filtering the halogenated phenolic residual from the halogenated solution to produce a partially purified HX stream, and passing the partially purified HX stream through an adsorbent bed to produce a purified HX stream, wherein the adsorbent bed comprises a carbon bed or a polystyrene bed.

[0058] Embodiment 3. A process for purifying an HBr stream containing about 1 wt% or less phenolic residuals, wherein the HBr stream containing about 15 wt% or less HBr is treated with bromine as the halogen at above 60°C to brominate the phenolic residuals and produce a halogenated solution. The halogenated solution can be cooled to below 60°C and filtered to produce a partially purified HBr stream. The partially purified HBr stream can be further processed by passing it through an adsorbent bed.

[0059] Embodiment 4. The process of any one of the preceding embodiments, wherein the oxidative halogenation is carried out at about 60° C. or higher, 80° C. or higher, or 90° C. or higher.

[0060] Embodiment 5. The process of any preceding embodiment, wherein the reactants are cooled to a temperature at least about 20° C. below the halogenation temperature. The reactants may be cooled to about 60° C. or less. The reactants may be cooled to about 40° C. or less.

[0061] Embodiment 6. The process of any preceding embodiment, wherein the ratio of halogen to phenolic residue is about 2:1 to 20:1 wt / wt. The ratio of halogen to phenolic residue may be about 8:1 to 12:1 wt / wt.

[0062] Embodiment 7. The process of any preceding embodiment, wherein the HX stream contains less than about 5 wt.%, less than about 3 wt.%, or less than about 1 wt.% phenolic residuals.

[0063] Embodiment 8. The process of any one of the preceding embodiments, wherein the HX stream is less than about 30 wt.% HX, less than about 20 wt.% HX, less than about 15 wt.% HX, or less than about 12 wt.% HX.

[0064] Embodiment 9. The process of any preceding embodiment, wherein the HX stream, the partially purified HX stream, and the purified HX stream each contain HBr.

[0065] Embodiment 10. The process of any one of the preceding embodiments, wherein the oxidative halogenation is oxidative bromination, the halogen being bromine.

[0066] The embodiments and claims disclosed herein are to be understood as not being limited in their application to the details of construction and the arrangement of components described in the specification and illustrated in the drawings. Rather, the specification and drawings provide examples of embodiments contemplated. The embodiments and claims disclosed herein further provide for the understanding that other embodiments may be practiced. and can be practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting the scope of the claims.

[0067] As such, those skilled in the art will appreciate that the idea(s) on which the specification and claims are based may be readily utilized as a basis for the designing of other structures, methods and systems for carrying out some of the purposes of the embodiments and claims presented herein, and it is important that the claims be regarded as including such equivalent structures.

Claims

1. 1. A process for purifying a HX stream containing phenolic residues, comprising: treating the HX stream by oxidative halogenation to halogenate the phenolic residue to produce a halogenated phenolic residue and a halogenated solution; cooling the halogenated solution; filtering the halogenated phenolic residue from the halogenated solution to produce a partially purified HX stream; The process wherein the HX stream comprises an HCl stream, an HBr stream, an HI stream, or a combination thereof.

2. 10. The process of claim 1, further comprising passing the partially purified HX stream through an adsorbent bed to produce a purified HX stream.

3. 3. The process of any of claims 1-2, wherein the HX stream contains less than about 5 wt% phenolic residuals.

4. 3. The process of any of claims 1-2, wherein the HX stream contains less than about 1 wt% phenolic residuals.

5. 3. The process of claim 1, wherein the HX stream is less than about 30 wt% HX.

6. 3. The process of any of claims 1-2, wherein the HX stream is less than about 15 wt% HX.

7. 3. The process of claim 1, wherein the HX stream, the partially purified HX stream, and the purified HX stream each contain HBr.

8. 3. The process of any of claims 1 to 2, wherein the oxidative halogenation is oxidative bromination, the halogen being bromine.

9. 3. The process of claim 1, wherein the oxidative halogenation is carried out at about 60° C. or above.

10. 3. The process of claim 1, wherein the oxidative halogenation is carried out at about 90° C. or above.

11. 3. The process of any of claims 1-2, wherein the reactants are cooled to a temperature at least about 20°C below the halogenation temperature.

12. The process of any of claims 1-2, wherein the reaction is cooled to about 60°C or below.

13. 3. The process of any of claims 1-2, wherein the reaction is cooled to about 40°C or less.

14. 3. The process of any of claims 1-2, wherein the ratio of halogen to phenolic residue is about 2:1 to 20:1 wt / wt.

15. 3. The process of any of claims 1-2, wherein the ratio of halogen to phenolic residue is about 8:1 to 12:1 wt / wt.

16. The process of claim 2 , wherein the adsorbent layer comprises a carbon layer or a polystyrene layer.