CROSS REFERENCE TO RELATED APPLICATIONS

[0001] None.

FIELD OF INVENTION

[0002] The present disclosure generally relates to the processing of liquids with off- specification polypropylene materials. More specifically, the present disclosure involves the demineralization of water with an ion-exchange system that includes off-specification polypropylene materials.

BACKGROUND OF THE INVENTION

[0003] In chemical processing plants, there will, inevitably, be instances when the end product does not meet the specifications established for the intended product. In some instances, the off- specification product is reprocessed or is made to undergo additional processing to meet the specifications. Another alternative is that the customer for the product may demand a discount and/or waive the requirement to meet all specifications, especially if the specification that has not been met is not critical to the customer. A further alternative for resolving the issue of off- specification product is to discard the product. These different methods of addressing the problem of off-specification product can be costly.

[0004] Like most other industrial processes, the process of producing polypropylene often results in the production of off-specification product. But in the case of polypropylene, the off- specification product is not usually amenable to reprocessing or further processing to get it to meet specifications. Consequently, there is a need to address the potential costs related to off- specification polypropylene.

BRIEF SUMMARY OF THE INVENTION

[0005] The present inventors have recognized that at least one or more of the problems associated with off-specification polypropylene can be solved, in embodiments of the disclosure, by repurposing the off-specification polypropylene from its intended use to a new use. According to embodiments of the disclosure, off-specification polypropylene can be used in an ion exchange system for the processing of a liquid. In particular, in embodiments of the disclosure, off- specification polypropylene can be used in an ion-exchange system to demineralize water. When the ion exchange system is located near or at the polypropylene processing plant, there is a benefit of low transportation costs associated with utilizing the off-specification polypropylene for a different purpose than originally intended.

[0006] Embodiments of the disclosure include a method of processing liquids. The method comprises flowing a liquid into an ion exchange system, wherein the ion exchange system comprises an ion exchange resin and off-specification polypropylene pellets. The method further includes contacting the liquid with the ion exchange resin and flowing a processed liquid from the ion exchange system.

[0007] Embodiments of the disclosure include a method of demineralizing a liquid comprising water. The method comprises flowing the liquid into an ion exchange system, wherein the ion exchange system comprises an anion exchange resin and/or a cation exchange resin, and off-specification polypropylene pellets. The method further includes contacting the liquid with the anion exchange resin and/or the cation exchange resin and flowing a processed liquid from the ion exchange system.

[0008] Embodiments of the disclosure include an ion exchange system. The ion exchange system comprises an ion exchange resin and off-specification polypropylene pellets.

[0009] The following includes definitions of various terms and phrases used throughout this specification.

[0010] The terms “about” or “approximately” are defined as being close to as understood by one of ordinary skill in the art. In one non-limiting embodiment the terms are defined to be within 10%, preferably, within 5%, more preferably, within 1%, and most preferably, within 0.5%.

[0011] For the purposes of this disclosure, “X, Y, and/or Z” can be construed as X only, Y only, Z only, or any combination of two or more items X, Y, and Z (e.g., XYZ, XY, XZ, YZ). [0012] The terms “wt. %”, “vol. %” or “mol. %” refer to a weight, volume, or molar percentage of a component, respectively, based on the total weight, the total volume, or the total moles of material that includes the component. In a non-limiting example, 10 moles of component in 100 moles of the material is 10 mol. % of component.

[0013] The term “substantially” and its variations are defined to include ranges within 10%, within 5%, within 1%, or within 0.5%.

[0014] The terms “inhibiting” or “reducing” or “preventing” or “avoiding” or any variation of these terms, when used in the claims and/or the specification, include any measurable decrease or complete inhibition to achieve a desired result.

[0015] The term “effective,” as that term is used in the specification and/or claims, means adequate to accomplish a desired, expected, or intended result.

[0016] The use of the words “a” or “an” when used in conjunction with the term “comprising,” “including,” “containing,” or “having” in the claims or the specification may mean “one,” but it is also consistent with the meaning of “one or more,” “at least one,” and “one or more than one.”

[0017] The words “comprising” (and any form of comprising, such as “comprise” and “comprises”), “having” (and any form of having, such as “have” and “has”), “including” (and any form of including, such as “includes” and “include”) or “containing” (and any form of containing, such as “contains” and “contain”) are inclusive or open-ended and do not exclude additional, unrecited elements or method steps.

[0018] The process of the present invention can “comprise,” “consist essentially of,” or “consist of’ particular ingredients, components, compositions, etc., disclosed throughout the specification.

[0019] The term “primarily,” as that term is used in the specification and/or claims, means greater than any of 50 wt. %, 50 mol. %, and 50 vol. %. For example, “primarily” may include 50.1 wt. % to 100 wt. % and all values and ranges there between, 50.1 mol.% to 100 mol.% and all values and ranges there between, or 50.1 vol. % to 100 vol. % and all values and ranges there between. [0020] Other objects, features and advantages of the present invention will become apparent from the following figures, detailed description, and examples. It should be understood, however, that the figures, detailed description, and examples, while indicating specific embodiments of the invention, are given by way of illustration only and are not meant to be limiting. Additionally, it is contemplated that changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. In further embodiments, features from specific embodiments may be combined with features from other embodiments. For example, features from one embodiment may be combined with features from any of the other embodiments. In further embodiments, additional features may be added to the specific embodiments described herein.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] For a more complete understanding, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

[0022] FIG. 1 shows an ion exchange system, according to embodiments of the disclosure; and

[0023] FIG. 2 shows a method of processing a liquid, according to embodiments of the disclosure.

DETAILED DESCRIPTION OF THE INVENTION

[0024] The present disclosure involves the processing of a liquid with an ion exchange system that includes off-specification polypropylene material. According to embodiments of the disclosure, off-specification polypropylene material can be utilized as inert material over anion and cation beds, in a water demineralization plant. In this way, according to embodiments of the disclosure, the systems and methods described herein not only provide an inexpensive and viable alternative inert material used in the demineralization water plant but also increase the value of off-specification polypropylene materials. In embodiments of the disclosure, polypropylene is produced as pellets, and as noted earlier, the product process sometimes results in off-specification product, in this case, off-specification polypropylene pellets. [0025] The term “off-specification polypropylene pellets” as that term is used in the specification and/or claims, means pellets comprising at least 90 wt. % polypropylene and having at least one of the following characteristics (TABLE 1) not being in the range shown for that characteristic.

TABLE 1

Polypropylene Pellets Specifications

[0026] According to embodiments of the disclosure, “off-specification polypropylene pellets” can be defined as pellets comprising at least 90 wt. % polypropylene and having at least one of a subset of the characteristics in TABLE 1 not being in the range shown for that characteristic. In embodiments of the disclosure, off-specification polypropylene pellets 102 are as described in TABLE 2.

TABLE 2

Ion Exchange Systems [0027] FIG. 1 shows an ion exchange system 10, according to embodiments of the disclosure.

FIG. 2 shows a method 20 for processing a liquid, according to embodiments of the disclosure. In embodiments of the disclosure, method 20 is implemented using ion exchange system 10.

[0028] In embodiments of the disclosure, ion exchange system 10 includes an ion exchange resin vessel 101, in which is disposed off-specification polypropylene pellets 102 on top of an ion exchange resin 103. Ion exchange resin 103, according to embodiments of the disclosure, comprises an anion exchange resin and/or a cation exchange resin. The anion exchange resin, in embodiments of the disclosure, may include a polyacrylic matrix, a polyacrylic-divinylbenzene matrix, or a styrene-divinylbenzene polymer matrix containing carboxylic acid or sulfonic functional groups, or combinations thereof. The cation exchange resin, in embodiments of the disclosure, may include a cross linked acrylic matrix, a polyacrylic-divinylbenzene matrix, or a styrene-divinylbenzene polymer matrix containing dimethylethanol amine, dimethylamine or polyamine or primary amine or secondary amine or tertiary amine or quaternary amine functional groups or N+(CHs)3 groups (type 1 resins) or -N+CH3)2C2H4OH groups (type 2 resins), or combinations thereof.

[0029] According to embodiments of the disclosure, ion exchange system 10 is adapted to process a liquid 100 to produce a processed liquid 104. In embodiments of the disclosure, liquid 100 is a liquid that comprises primarily water. Ion exchange system 10 is used to demineralize liquid 100 to produce processed liquid 104, which includes less impurities than liquid 100 (purified water). In embodiments of the disclosure, the ion exchange system comprises a plurality ion exchange resin vessels, which may be any combination of cation exchange resin vessels and anion exchange resin vessels.

Method of Processing a Liquid

[0030] Method 20, according to embodiments of the disclosure, includes, at block 200, flowing liquid 100 into ion exchange system 10. Ion exchange system 10, according to embodiments of the disclosure, includes an ion exchange resin vessel 101, which has disposed therein off-specification polypropylene pellets 102 (serving as an inert material in the process) on top of ion exchange resin 103. The polypropylene inert material, of which, in embodiments of the disclosure, off-specification polypropylene pellets 102 are made, is highly resistant to attrition and does not react with acid or caustic during regeneration cycles. Inert polypropylene material of off- specification polypropylene pellets 102, according to embodiments of the disclosure, has a specific gravity lower than that of water and so is capable of floating just above the ion exchange bed of ion exchange resin 103. In this way, according to embodiments of the disclosure, off-specification polypropylene pellets 102 are used as an upper layer in ion exchange system 10. Ion exchange system 10, according to embodiments of the disclosure, can be a countercurrent regeneration type packed system, a partially packed system, or a fluidized bed ion exchange system.

[0031] According to embodiments of the disclosure, inert polypropylene material (off- specification polypropylene pellets 102) is used as a compression bed above a resin bed (ion exchange resin 103). This arrangement prevents finer ion exchange resin from reaching strainer nozzles, located at the bottom of ion exchange resin vessel 101 (not shown), thus avoiding them being clogged. Off-specification polypropylene pellets 102 allows any insoluble matter trapped within the resin bed during loading cycle to be passed out during regeneration. A further benefit of off-specification polypropylene pellets 102, according to embodiments of the disclosure, is that it improves the distribution of water and the collection of spent regenerant in the top part of ion exchange resin vessel 101.

[0032] At block 201, method 20 includes, according to embodiments of the disclosure, contacting liquid 100 with ion exchange resin 103, which occurs as liquid 100 flows through off- specification propylene pellets 102 and then through ion exchange resin 103. In this way, ion exchange resin 103 removes particular materials, via ion exchange, from liquid 100. For example, ion exchange resin may comprise one or more of the following anion exchange resins: polyacrylic matrix, polyacrylic-divinylbenzene matrix, or styrene-divinylbenzene polymer matrix containing carboxylic acid or sulfonic functional groups. Alternatively or additionally, the ion exchange resin may comprise one or more of the following cation exchange resins: cross linked acrylic matrix, polyacrylic-divinylbenzene matrix, or styrene-divinylbenzene polymer matrix containing dimethylethanol amine, dimethylamine or polyamine or primary amine or secondary amine or tertiary amine or quaternary amine functional groups or N+(CH3)3 groups (type 1 resins) or - N+CH3)2C2H4OH groups (type 2 resins). Method 20, at block 202, includes flowing a processed liquid from ion exchange system 10. In embodiments of the disclosure, method 20 involves demineralizing a liquid comprising water by flowing the water through ion exchange system 10.

EXAMPLE

(Test to show effect of using off-specification polypropylene pellets in ion exchange system of a demineralization plant)

[0033] The present invention will be described in greater detail by way of a specific example. The following example is offered for illustrative purposes only, and is not intended to limit the invention in any manner. Those of skill in the art will readily recognize a variety of noncritical parameters which can be changed or modified to yield essentially the same results.

[0034] A test was carried out at a demineralization plant to determine the effect of using off- specification polypropylene pellets in an ion exchange system of a demineralization plant. The ion exchange system before the trial included ion exchange resin but no off-specification polypropylene pellets. The ion exchange system during the trial included ion exchange resin and off-specification polypropylene pellets. The results of the trial are shown in Table 3. As shown in Table 3, there is no resin breakthrough when off-specification polypropylene pellets were used in the ion exchange system. The fact that there was no resin breakthrough is the most critical improvement, in this particular trial.

TABLE 3

[0035] Although embodiments of the present disclosure have been described with reference to blocks of FIG. 2 it should be appreciated that operation of the present disclosure is not limited to the particular blocks and/or the particular order of the blocks illustrated in FIG. 2. Accordingly, embodiments of the disclosure may provide functionality as described herein using various blocks in a sequence different than that of FIG. 2.

[0036] In the context of the present invention, at least the following 15 embodiments are described. Embodiment 1 is a method of processing liquids. The method includes flowing a liquid into an ion exchange system, wherein the ion exchange system comprises an ion exchange resin and off-specification polypropylene pellets. The method further includes contacting the liquid with the ion exchange resin. The method still further includes flowing a processed liquid from the ion exchange system. Embodiment 2 is the method of embodiment 1, wherein the off-specification polypropylene pellets comprise at least one of the following: less than 3.2 or more than 3.8 wt. % xylene solubles, greater than 3.0 mg/kg titanium, greater than 120 mg/kg aluminum, greater than 3.0 mg/kg iron, greater than 75 mg/kg chloride, and greater than 20% fines. Embodiment 3 is the method of embodiment 1, wherein the processing comprises demineralizing a liquid comprising water. Embodiment 4 is the method of any of embodiments 1 to 3, wherein the ion exchange resin comprises an anion exchange resin and/or a cation exchange resin. Embodiment 5 is the method of embodiment 4, wherein the ion exchange resin comprises the anion exchange resin, and further wherein the anion exchange resin comprises a polyacrylic matrix, a polyacrylic-divinylbenzene matrix, or a styrene-divinylbenzene polymer matrix containing carboxylic acid or sulfonic functional groups, or combinations thereof. Embodiment 6 is the method of embodiment 4, wherein the ion exchange resin comprises the cation exchange resin, and further wherein the cation exchange resin comprises a cross linked acrylic matrix, a polyacrylic-divinylbenzene matrix, or a styrene-divinylbenzene polymer matrix containing dimethylethanol amine, dimethylamine or polyamine or primary amine or secondary amine or tertiary amine or quaternary amine functional groups or N+(CHs)3 groups (type 1 resins) or -N+(CH3)2C2H4OH groups (type 2 resins), or combinations thereof. Embodiment 7 is the method of any of embodiments 1 to 6, wherein the off- specification polypropylene pellets are disposed above the ion exchange resin in an ion exchange resin vessel.

[0037] Embodiment 8 is an ion exchange system. The ion exchange system includes an ion exchange resin and off-specification polypropylene pellets. Embodiment 9 is the ion exchange system of embodiment 8, wherein the off-specification polypropylene pellets comprise at least one of the following: less than 3.2 or more than 3.8 wt. % xylene solubles, greater than 3.0 mg/kg titanium, greater than 120 mg/kg aluminum, greater than 3.0 mg/kg iron, greater than 75 mg/kg chloride, and greater than 20% fines. Embodiment 10 is the ion exchange system of embodiment 8, wherein the ion exchange system is adapted to demineralize a liquid comprising water. Embodiment 11 is the ion exchange system of any of embodiments 8 to 10, wherein the ion exchange resin comprises an anion exchange resin and/or a cation exchange resin. Embodiment 12 is the ion exchange system of embodiment 11, wherein the ion exchange resin comprises the anion exchange resin, and further wherein the anion exchange resin comprises a polyacrylic matrix, a polyacrylic-divinylbenzene matrix, or a styrene-divinylbenzene polymer matrix containing carboxylic acid or sulfonic functional groups, or combinations thereof. Embodiment 13 is the ion exchange system of embodiment 11, wherein the ion exchange resin comprises the anion exchange resin, and further wherein the anion exchange resin comprises a cross linked acrylic matrix, a polyacrylic-divinylbenzene matrix, or a styrene-divinylbenzene polymer matrix containing dimethylethanol amine, dimethylamine or polyamine or primary amine or secondary amine or tertiary amine or quaternary amine functional groups or N+(CHs)3 groups (type 1 resins) or -N+(CH3)2C ₂ H ₄ OH groups (type 2 resins), or combinations thereof. Embodiment 14 is the ion exchange system of any of embodiments 8 to 13, wherein the off-specification polypropylene pellets are disposed above the ion exchange resin in an ion exchange resin vessel. Embodiment 15 is the ion exchange system of any of embodiments 8 to 13, wherein the ion exchange system comprises a plurality of cation exchange resin vessels and/or a plurality of anion exchange resin vessels.

[0038] The systems and processes described herein can also include various equipment that is not shown and is known to one of skill in the art of chemical processing. For example, some controllers, piping, computers, valves, pumps, heaters, thermocouples, pressure indicators, mixers, heat exchangers, and the like may not be shown. All embodiments described above and herein can be combined in any manner unless expressly excluded.

[0039] Although embodiments of the present application and their advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the embodiments as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the above disclosure, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.