Monomer recovery process

Abstract

To provide a process for recovering and recycling a monomer and a solvent in a waste supply stream resulting from a copolymer polyol manufacturing process.SOLUTION: A process including the steps of:(a) providing a waste supply stream containing a styrene monomer, an acrylonitrile monomer, a solvent and impurities and resulting from a copolymer polyol manufacturing process; (b) subjecting the waste supply stream of step (a) to a separation process under conditions for separating the monomers and solvent from the impurities, the separation process including forming a plurality of overhead streams, a side stream, and a bottom stream; (c) recovering the monomers and solvent in the plurality of streams; and (d) passing the one or more of the monomer and solvent from step (c) to a supply stream of a copolymer polyol manufacturing process.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a process for recovering monomers and solvents from waste streams generated by a copolymer polyol (CPP) composition production process.

Summary of the Invention

Problems to be Solved by the Invention

[0002] Generally, in the production process for producing polyurethane foam, a reaction mixture of a polyol and other additives such as a polyisocyanate and a catalyst is used to prepare a foam-forming polyurethane reaction mixture composition, and this can be used to produce polyurethane foam. Copolymer polyol (CPP) can be used as a polyol reactant in the reaction step of the foam manufacturing process and is highly desired. That is, the CPP reactant reacts with the polyisocyanate reactant in the production of polyurethane (PU) foam. A typical CPP product can be a stable dispersion of styrene-acrylonitrile (SAN) copolymer particles suspended in a polyether polyol.

[0003] Heretofore, known CPP stable dispersion products used as reactants in the foam-forming process usually have a fairly high concentration of residual monomers (especially, for example, styrene and acrylonitrile monomers) present in the final CPP dispersion product after CPP is produced. The residual monomers are the unconverted portions of the reactants from the dispersion polymerization reaction step before the process of producing SAN particles in the polyether polyol. To produce SAN particles In processes for this purpose, typically residual monomers are removed from the product after the polymerization reaction step described above. Typically, stripping can be accomplished by a variety of different methods (e.g., Switching and continuous systems, single stage, or multi-stage) with a variety of stripping agents (e.g. , nitrogen, isopropanol, steam, etc.).

[0004] Referring to FIG. 1, a first reactor 20, a second reactor 30, a distillation column 40 (e.g., a tripping tower 40), and a waste storage vessel 50 for producing a CPP product. A known general process for the above process is shown, generally designated by the reference numeral 10. In this process, a monomer feed stream 21 enters a first reactor 20 and the feed stream The monomers present in the copolymer 21, such as styrene and acrylonitrile, are partially reacted. The reaction mixture then passes via stream 22 to second reactor 30. In the reactor 30, the monomers are further reacted to form the CPP product and residual monomers and solvent. The mixture with the catalyst exits reactor 30 as stream 31. The stream 31 passes to a distillation / stripping column 40 to separate the CPP product from waste products, etc. Any undesirable materials are separated (i.e., stripped). The product leaves column 40 as product stream 41, and the waste product is transferred to waste storage vessel 50. The waste product stream 42 exits the column 40. One major challenge is the presence of styrene and acrylonitrile in the waste stream42. There is still a significant amount of residual useful monomer remaining. A significant loss of unreacted monomer and solvent, which is wasteful. Typically, up to this point, waste stream 42 has been sent to storage unit 50 to be discarded or await disposal. It would be desirable and advantageous to provide a novel process for removing all or substantially all of the residual monomer from the stripped waste stream 42 so that the recovered residual monomer can be recycled back to monomer feed stream 21 for reuse. Such a desirable novel CPP process could be more efficient and less costly than previously known CPP production processes. Up to this point, waste stream 42 has been sent to storage unit 50 to be discarded or await disposal. It would be desirable and advantageous to provide a novel process for removing all or substantially all of the residual monomer from the stripped waste stream 42 so that the recovered residual monomer can be recycled back to monomer feed stream 21 for reuse. Up to this point, waste stream 42 has been sent to storage unit 50 to be discarded or await disposal. It would be desirable and advantageous to provide a novel process for removing all or substantially all of the residual monomer from the stripped waste stream 42 so that the recovered residual monomer can be recycled back to monomer feed stream 21 for reuse. It would be desirable and advantageous to provide a novel process for removing all or substantially all of the residual monomer from the stripped waste stream 42 so that the recovered residual monomer can be recycled back to monomer feed stream 21 for reuse. Such a desirable novel CPP process could be more efficient and less costly than previously known CPP production processes. Such a desirable novel CPP process could be more efficient and less costly than previously known CPP production processes.

[0005] Various prior art references mention various ways of partial recovery of monomer and solvent as a mixture. However, it is not possible to use such a mixture as a recycle stream without additional steps. For example, removal of unwanted impurities that would be present in the stripped waste stream using prior art processes has not been addressed at all. If such impurities are present in the stream being recycled, the impurities present in the recycle stream can seriously affect the quality of the CPP product produced and, in turn, can seriously affect the quality of the foam made using such CPP. Various prior art references mention various ways of partial recovery of monomer and solvent as a mixture. However, it is not possible to use such a mixture as a recycle stream without additional steps. However, it is not possible to use such a mixture as a recycle stream without additional steps. For example, removal of unwanted impurities that would be present in the stripped waste stream using prior art processes has not been addressed at all. For example, removal of unwanted impurities that would be present in the stripped waste stream using prior art processes has not been addressed at all. If such impurities are present in the stream being recycled, the impurities present in the recycle stream can seriously affect the quality of the CPP product produced and, in turn, can seriously affect the quality of the foam made using such CPP. If such impurities are present in the stream being recycled, the impurities present in the recycle stream can seriously affect the quality of the CPP product produced and, in turn, can seriously affect the quality of the foam made using such CPP. If such impurities are present in the stream being recycled, the impurities present in the recycle stream can seriously affect the quality of the CPP product produced and, in turn, can seriously affect the quality of the foam made using such CPP. If such impurities are present in the stream being recycled, the impurities present in the recycle stream can seriously affect the quality of the CPP product produced and, in turn, can seriously affect the quality of the foam made using such CPP.

[0006] Another problem plaguing prior art processes is the difficulty of recovering acrylonitrile residual monomer, which has a tendency to form a minimum boiling azeotrope with water and such azeotropes can form during the CPP production process. Another problem plaguing prior art processes is the difficulty of recovering acrylonitrile residual monomer, which has a tendency to form a minimum boiling azeotrope with water and such azeotropes can form during the CPP production process. Another problem plaguing prior art processes is the difficulty of recovering acrylonitrile residual monomer, which has a tendency to form a minimum boiling azeotrope with water and such azeotropes can form during the CPP production process. This is because it is very difficult to separate acrylonitrile monomers. In the prior art None of the reference documents have solved the problem of separating water from the minimum-boiling azeotrope of acrylonitrile and water. For example, CN104045773A discloses the use of styrene and acrylonitrile monomers, as well as the use of isopropyl alcohol (IPA) solvent in the separation and recovery method for solvents during the production process of polymer polyols. The above reference document describes the recycling of solvents with a specific composition, but the above reference document does not mention how the solvent is separated from the product, nor does it mention the recovery or recycling of monomers.

[0007] CN106866893A discloses a method for preparing high-solid, low-volatile organic compound (VOC) polymer polyols, and also describes the use of a recycling container for monomer waste streams. However, the monomer waste stream is not purified before the waste stream is used.

[0008] U.S. Patent No. 2,807,573A discloses the purification of acrylonitrile by extractive distillation, and also describes the purification of a mixture of acrylonitrile and acetonitrile using a solvent. The solvents mentioned in the above patent include aqueous alkali salts. However, the above patent teaches the separation of the acrylonitrile-water azeotrope from a mixture containing acrylonitrile, acetonitrile, and water, but does not teach the decomposition of the azeotrope into the individual components in the azeotrope.

[0009] U.S. Patent No. 3,445,347 describes the side stream separation of the impurity stream. The present invention discloses the extractive distillation of acrylonitrile involving the use of water as the extractive solvent. The acrylonitrile-water azeotrope is collected at the top of the column, The components of an azeotrope cannot be separated from one another.

[0010] International Journal of Chemical and Molecular Engineering, Vol. 9, No. 2, 2015 The thing is, a different entre for the extractive distillation of acetonitrile (not acrylonitrile) The solvents mentioned in the above references include , butyl acetate, DMSO, ethylene glycol, DMF, glycerol, and pyridine with preference given to glycerol.

[0011] Chemical Engineering Research and Desi The article in gn,99(2015),pp 125-131, describes 1,2-ethanediol and They disclose the separation of ternary mixtures by extractive distillation using acrylic acid and glycerol. Using DMSO and glycerol for extractive distillation of isopropyl nitrile-water. The above references and other prior art references describe the use of acrylonitrile and water. The present invention does not provide a method for separating water from its minimum boiling azeotropic mixture with water. It is desirable to provide a solution.

[0012] The present invention relates to a process for producing a waste feed stream containing monomers, solvents, and impurities, comprising: (b) providing a waste stream from step (a); and a step of subjecting to a separation process under conditions for separating monomers and solvents from the impurities of the waste, (c) a step of recovering monomers and solvents in one or more streams, and ( d) a step of transferring one or more streams of monomers and solvents from step (c) to further processing, and a process for recovering monomers and solvents present in the waste stream is targeted.

[0013] In one preferred embodiment, the process for recovering monomers present in the waste stream is (a) at least one solvent and at least one styrene monomer and a waste feed stream containing at least one acrylonitrile monomer, and (b) a step of subjecting the waste feed stream of step (a) or a pre-distilled mixture to extractive distillation, wherein the mixture can contain at least one monomer of a solvent, styrene monomer and water as an azeotropic composition, a step and (c) a step of separating the solvent, styrene monomer, and acrylonitrile monomer from the waste feed stream of step (a), and (d) recycling, further processing, or storing the solvent, styrene monomer, and acrylonitrile monomer in two or more separate streams. including a step of recovering.

[0014] In another embodiment, the streams of solvent, styrene monomer, and acrylonitrile monomer separated and recovered by the process of the present invention can be used in a process for producing copolymer polyol, and the separation and recovery method of the present invention is (1) mo ​​​​​One of the monomers (e.g., styrene or acrylonitrile), (2) a solvent, and is (3) In addition to the solvent (e.g., toluene or isopropanol) from the waste stream, any advantageous combination of monomers (e.g., styrene and acrylonitrile) is used to produce a stream with a purity greater than (>) 98.5 percent (%). It can be used for this purpose.

[0015] Typically, the waste stream containing the solvent, styrene monomer, and acrylonitrile monomer is separately collected during a known process for producing CPP products. On the other hand, in the present invention, pure streams of monomers and solvents can be recovered from the generated waste stream, and then the pure streams are recycled back to the reactor used in the CPP production process. The process of the present invention provides a significant reduction in the waste produced in the CPP production process and also provides a significant reduction in the raw materials consumed in the CPP production process. The process of the present invention provides a significant reduction in the waste produced in the CPP production process and also provides a significant reduction in the raw materials consumed in the CPP production process.

[0016] Styrene and toluene can be easily recovered from the process waste stream using conventional distillation equipment (e.g., batch distillation or continuous distillation). However, the water present in the waste stream (typically less than 1 weight percent [wt%]) forms a minimum-boiling azeotrope with acrylonitrile, so the dehydration of acrylonitrile using conventional distillation is not practical. In one embodiment of the present invention, the problem of separating water from the minimum-boiling azeotrope of acrylonitrile and water can be solved. For example, in a preferred embodiment, an entrainer is used to increase the relative volatility of the acrylonitrile-water system. embodiment, an entrainer is used to increase the relative volatility of the acrylonitrile-water system.​​​​​​​​ It can be changed and the azeotrope can be decomposed. In another preferred embodiment, tripropy Glycols such as ethylene glycol (TPG) are used as the entrainer in the extractive distillation sequence to separate water from a >98.5% pure acrylonitrile stream. Water is not the desired product in the CPP production process, and thus, water is not recycled back to the reactor of the CPP production process. Instead, since water accumulates in the recycling and the system, it is desirable to remove water from the process of the present invention.

[0017] Pervaporation or adsorption is an alternative method that can be used to separate water from the acrylonitrile stream. However, the high reactivity of acrylonitrile limits the compatible membranes or adsorbent materials that can be used in the above-mentioned alternative methods. In addition, due to the high reactivity and toxicity of acrylonitrile, pervaporation is very expensive and difficult to handle, and the membranes used in the pervaporation method have a high turnover rate. Glycols such as TPG are relatively inexpensive solvents and have the desirable and necessary properties for water removal from the acrylonitrile-water azeotropic stream. Using glycols such as TPG in the extractive distillation sequence advantageously results in a >98.5% pure acrylonitrile stream. >98.5% pure acrylonitrile stream can be produced.

Brief Description of the Drawings

[0018]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

[0019] The copolymer polyol (CPP) reaction product is a stable dispersion of styrene - acrylonitrile (SAN) copolymer particles suspended in a polyether polyol. During the production process for producing the CPP reaction product, a waste stream from the SAN - CPP stripping step is produced. The waste stream can contain, for example, acrylonitrile, styrene, toluene, ethylbenzene, water, and other heavy impurities. In one broad embodiment, the present invention separates monomers such as acrylonitrile and styrene from the waste stream and re - uses the monomers for CPP production. process. It includes a process of recycling and returning it to the process.

[0020] Referring to FIG. 2, instead of discarding the waste stream (generated in the process of producing the CPP product) containing residual monomers and solvents, the process of the present invention, generally denoted by reference numeral 100, for producing a CPP product significantly different from the prior art processes is shown, and the waste stream is further processed to separate and recover the residual monomers and solvents for reuse (recycling) in the CPP process. The process of the present invention is advantageously efficient and saves costs associated with the residual monomers and solvents used in the CPP production process. Referring again to FIG. 2, the CPP production process 100 is shown to include a monomer separation and recovery system or scheme, generally denoted by reference numeral 200, for separating and recovering one or more monomers, and the monomer stream and solvent 211 exiting the recovery process 200 can be recycled back to the feed stream 121 of the CPP process. For example, stream 211 can combine with feed stream 121 to form a feed stream 212 that moves to the first reactor 120. The output stream 122 from the first reactor 120 moves to the second reactor 130. From the second reactor 130, the output stream 131 moves to the distillation column 140. In the distillation column 140, the CPP product stream 141 is separated from the waste stream 142, which is separated into one or more monomer streams 211 that can recycle the residual monomers in the waste feed stream 142 back to the CPP feed stream 121.

[0021] Referring again to FIG. 2, the CPP production process 100 is shown to include a monomer separation and recovery system or scheme, generally denoted by reference numeral 200, for separating and recovering one or more monomers, and the monomer stream and solvent 211 exiting the recovery process 200 can be recycled back to the feed stream 121 of the CPP process. For example, stream 211 can combine with feed stream 121 to form a feed stream 212 that moves to the first reactor 120. The output stream 122 from the first reactor 120 moves to the second reactor 130. From the second reactor 130, the output stream 131 moves to the distillation column 140. In the distillation column 140, the CPP product stream 141 is separated from the waste stream 142, which is separated into one or more monomer streams 211 that can recycle the residual monomers in the waste feed stream 142 back to the CPP feed stream 121. ​​​​​​​​​​​​​​​ Move. The monomer separation and recovery system 200 shown in FIG. 2 can include various systems, and examples of some preferred embodiments of such systems are described in more detail below in this specification. can include, and examples of some preferred embodiments of such systems are described in more detail below in this specification.

[0022] Referring to FIG. 3, a schematic flowchart of one broad embodiment of the process of the present invention, generally designated by reference numeral 300, for separating monomers such as acrylonitrile and styrene from a waste stream is shown. The process 300 of the present invention can include some distillation operations not found in prior art processes, such as a novel extractive distillation operation. Generally, the process 300 can include one or more towers, process steps, or operation schemes, generally designated by reference numeral 310. For example, a feed waste stream 311 can be moved to one or more distillation towers 310, and one or more monomer product streams and solvent streams 312 exit the tower 310. In addition, one or more waste streams such as a heavy matter stream 313, an overhead stream 314, and a side stream 315 can exit the tower 310. As used herein, "heavy matter" means a stream containing one or more impurities each having a boiling point above 150 degrees Celsius (°C) with respect to the process flow stream. Each of the streams 313, 314, and 315 can include one or more towers, one or more process steps, or one or more operation schemes for further separating the desired monomers and solvents from the waste stream. one broad embodiment, generally designated by reference numeral 300, for separating monomers such as acrylonitrile and styrene from a waste stream is shown. The process 300 of the present invention can include some distillation operations not found in prior art processes, such as a novel extractive distillation operation. Generally, the process 300 can include one or more towers, process steps, or operation schemes, generally designated by reference numeral 310. For example, a feed waste stream 311 can be moved to one or more distillation towers 310, and one or more mono mer product streams and solvent streams 312 exit the tower 310. In addition, heavy matter streams 313, overhead streams 314, and side streams 315 such as those described above can exit the tower 310. As used herein, "heavy matter" means a stream containing one or more impurities each having a boiling point above 150 degrees Celsius (°C) with respect to the process flow stream. Each of the streams 313, 314, and 315 can include one or more towers, one or more process steps, or operation schemes for further separating the desired monomers and solvents from the waste stream. As used herein, "heavy matter" means a stream containing one or more impurities each having a boiling point above 150 degrees Celsius (°C) with respect to the process flow stream. Stream 313 Each of 314, and 315 can include one or more towers, one or more process steps, or operation schemes for further separating the desired monomers and solvents from the waste stream. can include.

[0023] Referring to FIG. 4, residual monomers and solvents are separated and recovered from the waste stream A schematic flow chart of one embodiment of the process of the present invention, generally designated by reference numeral 400, is shown for this purpose. In the embodiment shown in FIG. 4, process 400 includes a distillation column 410. In process 400, waste stream 411 is fed to column 410, and the mixture of residual monomers and solvents contained in the waste stream is separated from other undesirable waste products in the waste stream, and the mixture of monomers and solvents exits column 410 via a mixed monomer / solvent stream 412. The mixture of residual monomers and solvents contained in the mixed monomer / solvent stream 41 2 can include, for example, solvents such as styrene monomer, acrylonitrile monomer, and toluene. The mixed monomer / solvent stream 41 2 is then recovered and can be recycled back to the monomer feed stream 121 of the CPP product production process 100 (shown in FIG. 2). The bottoms stream 413 from column 410 can be transferred for further processing operations, storage, or disposal. The overhead stream 414 from column 41 0 can be transferred for further processing operations, storage, or disposal. In one embodiment of the process shown in FIG. 4, the mixture of monomers and solvents exiting column 410 via the mixed stream of monomers and solvent stream 412 can include, for example, 50 wt% to 65 wt% solvent, 20 wt% to 30 wt% styrene, 15 wt% to 20 wt% acrylonitrile, less than 1 wt% water, ethylbenzene, and a combination of heavy materials. The overhead stream 414 from column 410 can be transferred for further processing operations, storage, or disposal.

[0024] In one embodiment of the process shown in FIG. 4, the mixture of monomers and solvents exiting column 410 via the mixed stream of monomers and solvent stream 412 can include, for example, 50 wt% to 65 wt% solvent, 20 wt% to 30 wt% styrene, 15 wt% to 20 wt% acrylonitrile, less than 1 wt% water, ethylbenzene, and a combination of heavy materials. ~65 wt% solvent, 20 wt% to 30 wt% styrene, 15 wt% to 20 wt% acrylonitrile, less than 1 wt% water, ethylbenzene, and a combination of heavy materials. can include a combination of, for example, 50 wt% to 65 wt% solvent, 20 wt% to 30 wt% styrene, 15 wt% to 20 wt% acrylonitrile, less than 1 wt% water, ethylbenzene, and heavy materials.

[0025] ​​Referring to FIG. 5, for separating and recovering residual monomers from a waste stream , a schematic flow chart of another embodiment of the process of the present invention, generally designated by reference numeral 500, is shown. In the embodiment shown in FIG. 5, process 500 includes a first distillation tower 5 10 and a second distillation tower 520. Process 500 can be used to separate and recover styrene monomer, which can then be recycled back to the monomer feed stream 121 of the CPP product production process 10 0 (shown in FIG. 2). In process 500, waste stream 511 is fed to the first tower 510, and the waste feed stream 511 is separated into three streams: (1) a solvent side stream 512 such as toluene, (2) a bottoms stream 513 containing styrene, and (3) an overhead stream 514 containing mostly an azeotropic mixture of acrylonitrile and water. The bottoms stream 513 from tower 510 is transferred as feed stream 513 to the second distillation tower 52 0, and the bottoms feed stream 513 is separated into another three streams: (1) a styrene monomer side stream 521, (2) a bottoms stream 522 which may be a waste stream, and (3) an upper overhead stream 523 containing ethylbenzene which can also be considered a waste stream of the process of the present invention. The styrene monomer stream 521 exiting tower 520 is then recovered and can be recycled back to the monomer feed stream 121 of the CPP product production process 100 (shown in FIG. 2). The toluene solvent side stream 512 from tower 510 may be moved to a storage location or recycled back to the CPP process.

[0026] ​​​​​​​​​​​ Referring to FIG. 6, a further alternative embodiment of the process of the present invention for separating and recovering residual monomers from a waste stream, generally designated by reference numeral 600, is shown in a schematic flowchart. In the embodiment shown in FIG. 6, process 600 includes a first distillation column 610 and a second conventional distillation column 620. In process 600, waste stream 611 is fed to first column 610, and waste feed stream 611 is separated into three streams: (1) a styrene monomer sidestream 612 that can be recycled back to CPP production process 100; (2) a bottoms stream 613; and (3) an overhead stream 614 that contains a mixture of compounds including acrylonitrile and water. The overhead stream 614 from column 610 moves as feed stream 614 to a second distillation column 620, and the overhead feed stream 614 is further separated into another three streams: (1) a stream 621 that is mostly composed of acrylonitrile and water and can contain toluene; (2) a waste stream that can be mainly composed of ethylbenzene and can contain toluene, bottoms stream 622; (3) a sidestream 623 that is mostly toluene and can move to a storage location or be recycled back to CPP production process 100.

[0027] Referring to FIG. 7, a further alternative embodiment of the process of the present invention for separating and recovering residual monomers from a waste stream, generally designated by reference numeral 700, is shown in a schematic flowchart. In the embodiment shown in FIG. 7, process system 700 It includes an extraction distillation column 710 and a separation distillation column 720. Process 700 can be used to separate and recover acrylonitrile monomer from an azeotropic mixture of acrylonitrile and water, which was difficult to implement in prior art processes. Subsequently, the recovered acrylonitrile monomer can be recycled back to the monomer feed stream 121 of the CPP product production process 100 (shown in Figure 2). In process 700, a feed stream 711 containing an azeotropic mixture of acrylonitrile and water is fed to an extraction distillation column 710, which is also supplied with an extraction distillation solvent (shown by stream 722). The bottom stream 712 exits the column 710, and the upper overhead purification stream of acrylonitrile 713 exits the column 710 near the top of the column. The bottom stream 712 exiting the column 710 contains other products such as water and the extraction solvent. In the preferred embodiment shown in Figure 7, the bottom stream 712 can be fed to a separation column 720 to separate the water (an undesired product) contained in the feed stream 712 from the desired extraction solvent. The water stream 721 exits the column 720 near the top of the column 720, and the bottom stream 722 exiting the column 720 can be recycled back to the extraction distillation column 710 via stream 722. In other embodiments, the extraction distillation scheme 700 shown in Figure 7 can be used in combination with the scheme 500 shown in Figure 5 in one embodiment, or the scheme 600 shown in Figure 6 in another embodiment. For example, when the scheme 700 is used in combination with the scheme 500, the stream 514 is the feed stream (711) to the column 710.

[0028] Yes, this is also discussed below as feed stream 814 in separation scheme 800 shown in FIG. 8. When scheme 700 is used in combination with scheme 600, stream 621 becomes the feed stream (711) to column 710.

[0029] Referring to FIG. 8, a schematic flowchart of one general embodiment of the process of the present invention, generally designated by reference numeral 800, for separating and recovering residual monomers and solvents from a waste stream is shown. In the embodiment shown in FIG. 8, process system 800 is a combination of several operations for separating and recovering several monomers and solvents. Process 800 includes, for example, a first distillation column 810, a second distillation column 82 0, an extractive distillation column 830, and a separation distillation column 840. Process 800 can be used, for example, to separate and recover styrene monomer, acrylonitrile monomer from an azeotropic mixture of acrylonitrile and water, and solvents such as toluene. In the general embodiment shown in FIG. 8, each of columns 810, 820, 830, and 840 can have one or more feed streams and one or more discharge streams, respectively. In addition, each of columns 810, 820, 830, and 840 can include a condenser (not shown) incorporated into the process scheme shown in FIG. 8 after the overhead stream to form an overhead product stream, and each of columns 810, 820, 83 0, and 840 can include a reboiler (not shown) incorporated into the process scheme shown in FIG. 8 after the bottom stream to form a bottom or heavy product output stream. In the general embodiment shown in FIG. 8, each of columns 810, 820, 830, and 840 can have one or more feed streams and one or more discharge streams, respectively. In addition, each of columns 810, 820, 830, and 840 can include a condenser (not shown) incorporated into the process scheme shown in FIG. 8 after the overhead stream to form an overhead product stream, and each of columns 810, 820, 830, and 840 can include a reboiler (not shown) incorporated into the process scheme shown in FIG. 8 after the bottom stream to form a bottom or heavy product output stream. In the general embodiment shown in FIG. 8, each of columns 810, 820, 830, and 840 can have one or more feed streams and one or more discharge streams, respectively. In addition, each of columns 810, 820, 830, and 840 can include a condenser (not shown) incorporated into the process scheme shown in FIG. 8 after the overhead stream to form an overhead product stream, and each of columns 810, 820, 830, and 840 can include a reboiler (not shown) incorporated into the process scheme shown in FIG. 8 after the bottom stream to form a bottom or heavy product output stream. stream, and each of columns 810, 820, 830, and 840 can include a reboiler (not shown) incorporated into the process scheme shown in FIG. 8 after the bottom stream to form a bottom or heavy product output stream. stream, and each of columns 810, 820, 83 0, and 840 can include a reboiler (not shown) incorporated into the process scheme shown in FIG. 8 after the bottom stream to form a bottom or heavy product output stream. stream, and each of columns 810, 820, 830, and 840 can include a reboiler (not shown) incorporated into the process scheme shown in FIG. 8 after the bottom stream to form a bottom or heavy product output stream. can include.

[0030] Referring again to FIG. 8, the waste feed stream 811 is fed to the first distillation column 810 and separated into three streams: (1) an overhead stream 814, (2) a side stream 812 of a solvent such as toluene, and (3) a bottoms stream 813. The overhead stream 814 moves from the first distillation column 810 to further processing in a draw distillation column 830 (described below herein). The side stream 812 moves from the column 810 to a storage location or is recycled back to the process 100. The bottoms stream 813 moves from the column 810 to further processing in a second distillation column 820. When performing the first distillation in column 810, the reboiler temperature for the distillation can be 50°C to 90°C in one embodiment, 60°C to 75°C in another embodiment, and 60°C to 65°C in yet another embodiment. The reboiler pressure in column 810 can be 0.5 pounds per square inch (psi) (3.4 kPa [kilopascal]) to 5 psi (34.4 kPa) in one embodiment, 0.5 psi (3.4 kPa) to 2 psi (13.8 kPa) in another embodiment, and 0.7 psi (4.8 kPa) to 1.1 psi (7.6 kPa) in yet another embodiment. Referring again to FIG. 8, the bottoms stream 813 from column 810 is fed to the second distillation column 820 as feed stream 813 and separated into three streams: (1) an overhead stream 823, (2) a side stream 821 of styrene, and (3) a bottoms stream 822. The overhead stream 823

[0031] When performing the first distillation in column 810, the reboiler temperature for the distillation can be 50°C to 90°C in one embodiment, 60°C to 75°C in another embodiment, and 60°C to 65°C in yet another embodiment. The reboiler pressure in column 810 can be 0.5 pounds per square inch (psi) (3.4 kPa [kilopascal]) to 5 psi (34.4 kPa) in one embodiment, 0.5 psi (3.4 kPa) to 2 psi (13.8 kPa) in another embodiment, and 0.7 psi (4.8 kPa) to 1.1 psi (7.6 kPa) in yet another embodiment. When performing the first distillation in column 810, the reboiler temperature for the distillation can be 50°C to 90°C in one embodiment, 60°C to 75°C in another embodiment, and 60°C to 65°C in yet another embodiment. The reboiler pressure in column 810 can be 0.5 pounds per square inch (psi) (3.4 kPa [kilopascal]) to 5 psi (34.4 kPa) in one embodiment, 0.5 psi (3.4 kPa) to 2 psi (13.8 kPa) in another embodiment, and 0.7 psi (4.8 kPa) to 1.1 psi (7.6 kPa) in yet another embodiment. When performing the first distillation in column 810, the reboiler temperature for the distillation can be 50°C to 90°C in one embodiment, 60°C to 75°C in another embodiment, and 60°C to 65°C in yet another embodiment. The reboiler pressure in column 810 can be 0.5 pounds per square inch (psi) (3.4 kPa [kilopascal]) to 5 psi (34.4 kPa) in one embodiment, 0.5 psi (3.4 kPa) to 2 psi (13.8 kPa) in another embodiment, and 0.7 psi (4.8 kPa) to 1.1 psi (7.6 kPa) in yet another embodiment. When performing the first distillation in column 810, the reboiler temperature for the distillation can be 50°C to 90°C in one embodiment, 60°C to 75°C in another embodiment, and 60°C to 65°C in yet another embodiment. The reboiler pressure in column 810 can be 0.5 pounds per square inch (psi) (3.4 kPa [kilopascal]) to 5 psi (34.4 kPa) in one embodiment, 0.5 psi (3.4 kPa) to 2 psi (13.8 kPa) in another embodiment, and 0.7 psi (4.8 kPa) to 1.1 psi (7.6 kPa) in yet another embodiment. When performing the first distillation in column 810, the reboiler temperature for the distillation can be 50°C to 90°C in one embodiment, 60°C to 75°C in another embodiment, and 60°C to 65°C in yet another embodiment. The reboiler pressure in column 810 can be 0.5 pounds per square inch (psi) (3.4 kPa [kilopascal]) to 5 psi (34.4 kPa) in one embodiment, 0.5 psi (3.4 kPa) to 2 psi (13.8 kPa) in another embodiment, and 0.7 psi (4.8 kPa) to 1.1 psi (7.6 kPa) in yet another embodiment. When performing the first distillation in column 810, the reboiler temperature for the distillation can be 50°C to 90°C in one embodiment, 60°C to 75°C in another embodiment, and 60°C to 65°C in yet another embodiment. The reboiler pressure in column 810 can be 0.5 pounds per square inch (psi) (3.4 kPa [kilopascal]) to 5 psi (34.4 kPa) in one embodiment, 0.5 psi (3.4 kPa) to 2 psi (13.8 kPa) in another embodiment, and 0.7 psi (4.8 kPa) to 1.1 psi (7.6 kPa) in yet another embodiment. When performing the first distillation in column 810, the reboiler temperature for the distillation can be 50°C to 90°C in one embodiment, 60°C to 75°C in another embodiment, and 60°C to 65°C in yet another embodiment. The reboiler pressure in column 810 can be 0.5 pounds per square inch (psi) (3.4 kPa [kilopascal]) to 5 psi (34.4 kPa) in one embodiment, 0.5 psi (3.4 kPa) to 2 psi (13.8 kPa) in another embodiment, and 0.7 psi (4.8 kPa) to 1.1 psi (7.6 kPa) in yet another embodiment.

[0032] Referring again to FIG. 8, the bottoms stream 813 from column 810 is fed to the second distillation column 820 as feed stream 813 and separated into three streams: (1) an overhead stream 823, (2) a side stream 821 of styrene, and (3) a bottoms stream 822. The overhead stream 823 is fed to the second distillation column 820 as feed stream 813 and separated into three streams: (1) an overhead stream 823, (2) a side stream 821 of styrene, and (3) a bottoms stream 822. The overhead stream 823 is fed to the second distillation column 820 as feed stream 813 and separated into three streams: (1) an overhead stream 823, (2) a side stream 821 of styrene, and (3) a bottoms stream 822. The overhead stream 823 is fed to the second distillation column 820 as feed stream 813 and separated into three streams: (1) an overhead stream 823, (2) a side stream 821 of styrene, and (3) a bottoms stream 822. The overhead stream 823​ , contains impurities that are not desired in the CPP process and, therefore, the overhead stream 823 can be discarded. Additional processing of stream 823 can be done, but such processing would not be practical for the recovery of relatively small amounts of valuable components . The side stream 821 of styrene monomer is recovered from column 820 and recycled to the process or moved to a storage location. The bottom stream 822 also contains impurities that are not desired in the CPP process and, therefore, the bottom stream 822 can be discarded.

[0033] When performing a second distillation in column 820, the reboiler temperature of the distillation is, in one embodiment, 4 0°C to 85°C, in another embodiment 55°C to 75°C, and in yet another embodiment 65°C to 70°C. Above 85°C, fouling may become a major issue, and below a temperature of 40°C, the temperature in the condenser may become negative, and problems such as ice or hydrate formation may occur due to the presence of water. The reboiler pressure in column 820 is, in one embodiment, 0.4 psi (2.8 kPa) to 4 psi (27.6 kPa), in another embodiment 0.4 psi (2.8 kPa) to 2 psi (13.8 kPa), and in yet another embodiment 0.6 psi (4.1 kPa) to 0.9 psi (6.2 kPa) .

[0034] Referring again to FIG. 8, the overhead stream 814 from the first distillation column 810 is used as feed stream 814 and is fed to the extractive distillation column 830 to split the feed stream 814 into two streams: (1) the overhead stream 8 32. And it is separated into the bottom stream 831 of the mixture of the extractive distillation solvent and water.

[0035] The overhead stream 832 of acrylonitrile is recovered from the column 830 and recycled to the process or transferred to a storage location. The bottom mixture stream 831 is transferred from the column 830 to further processing in a separation distillation column 840.

[0036] For example, in the extractive distillation operation occurring in the distillation column 830, the extractive solvent used in the extractive distillation scheme can be a polar solvent having a high affinity for water, such as tripropylene glycol (TPG); methyl propylene glycol (MPG); dipropylene glycol (DPG), ethylene glycol; other products from the glycol ether family such as dipropylene glycol monomethyl ether, propylene glycol methyl ether, etc.; and mixtures thereof.

[0037] When performing extractive distillation in the column 830, the reboiler temperature for extraction is, in one embodiment, 45 °C to 75 °C, in another embodiment 50 °C to 60 °C, and in yet another embodiment 50 °C to 55 °C. The pressure in the column 830 is, in one embodiment, 0.8 psi (5.5 kPa) to 10 psi (68.9 kPa), in another embodiment 1 psi (6.9 kPa) to 5 psi (34.4 kPa), and in yet another embodiment 1 .1 psi (7.6 kPa) to 1.9 psi (13.1 kPa) where the extraction is the most economical operation. Exceeding the temperature of 75 °C and the pressure of 68.9 kPa mentioned above may pose a problem of fouling due to the auto - polymerization of styrene, acrylonitrile, or a combination thereof. Below the 45 °C mentioned above, When it falls below the temperature of and a pressure of 5.5 kPa, additional refrigeration costs and vacuum costs need to be considered.

[0038] As an alternative to the operation in the extractive distillation column 830, and other embodiments instead of it In, the solvent and the monomer can be separated from the waste stream and water using, for example, membrane separation including vapor permeation and pervaporation, adsorption to a suitable adsorbent such as molecular sieves, and other similar operations or separation methods (not shown).

[0039] Referring to FIG. 8 again, the bottom mixed stream 831 from the column 830 is used as the feed stream 831 to the separation distillation column 8 40, and the feed stream 831 is separated into two streams: (1) the overhead stream 842 of water, and (2) the bottom stream 841 of the extractive distillation solvent. The overhead stream 842 of water moves from the column 840 to the wastewater treatment process and equipment. The bottom solvent stream 841 can be recovered and recycled back to the extractive distillation column 830 as shown in FIG. 8, or can be moved to a storage location .

[0040] When performing separation distillation in the column 840, the reboiler temperature of the distillation is, in one embodiment, 15 0 °C to 250 °C, in another embodiment 175 °C to 235 °C, and in yet another embodiment 200 °C to 210 °C. The reboiler pressure in the column 840 is, in one embodiment, 5 ps i (34.5 kPa) to 55 psi (379.2 kPa), in another embodiment 20 psi (137.9 kPa) to 50 psi (344.7 kPa), and in yet another embodiment can be 40 psi (275.8 kPa) to 50 psi (344.7 kPa).

[0041] In some embodiments of the process of the present invention, for example, as described above, generally, waste streams can contain an initial solvent content of 20 wt% to 60 wt%, an initial styrene monomer content of 10 wt% to 50 wt% an initial acrylonitrile monomer content of 5 wt% to 35 wt%, an initial ethylbenzene concentration of 0 wt% to 5 wt%, an initial water content of 0 wt% to 5 wt%, and an initial heavy matter content of 0 wt% to 5 wt%. Then, after separating the solvent, styrene monomer, and acrylonitrile monomer from the waste feed stream, in a preferred embodiment, the waste stream can contain a reduced solvent content of 0 wt% to 30 wt%, a reduced styrene monomer content of 0 wt% to 85 wt%, a reduced acrylonitrile monomer content of 0 wt% to 20 wt% as well as a reduced water content of 0 wt% to 5 wt%, and a reduced undesirable heavy matter content in the range of 0 wt% to 10 wt%.

[0042] In other embodiments, the process of the present invention can be carried out to advantageously remove an optimal amount of useful monomers and solvents. For example, in one embodiment, at least 30% of the solvent in the waste stream can be removed from the waste stream, at least 10% of the styrene monomer in the waste stream can be removed from the waste stream, at least 10% of the acrylonitrile monomer in the waste stream can be removed from the waste stream, and at least 90% of the water in the waste stream can be removed from the waste stream.

[0043] The monomers and solvents removed from the resulting waste stream comprise a stream that can be substantially purified when recovered from the waste stream For example, in one embodiment, the solvent stream removed from the waste stream can have a purity of at least 90%, the styrene monomer stream removed from the waste stream can have a purity of at least 98%, and the acrylonitrile monomer stream removed from the waste stream can have a purity of at least 90%.

[0044] Referring again to FIG. 2, when monomers and solvents (e.g., acrylonitrile, styrene , toluene, ethylbenzene, and water) are separated from waste stream 142 as recycle stream 211, in a preferred embodiment, the monomers and solvents are recycled via stream 211 for reuse in preparing the CPP product to a single reactor or a series of two or more reactors such as reactors 120 and 130 shown in FIG. 2. In another embodiment, the monomer and solvent streams can be moved to other facilities for further processing or to storage tanks for storage and later use.

[0045] The copolymer polyol (CPP) (also referred to as "modified polyol" or "polymer polyol" or "graft polyol") produced using the monomers and solvents recovered from the waste stream according to the present invention can be a blend or mixture of polyol compounds. Such CPP compounds are fully described in the prior art. ​​​​​​​​​​​, for example, examples of processes for manufacturing CPP products are described in U.S. Patent No. 4,513,12 No. 4,588,830, No. 4,640,935, No. 5,854,386 No. 4,745,153, No. 5,081,180, and No. 6,613,8 27, as well as EP1675885. Generally, the methods described in the above references involve dispersing low molecular weight monomers in the form of droplets in a polyol in the presence of a stabilizer and subjecting the dispersed monomer droplets to polymerization conditions until they are converted into solid polymer particles dispersed in the continuous polyol phase. This includes

[0046] For example, CPP products can be obtained by in situ polymerization of one or more vinyl monomers, such as styrene and acrylonitrile, in a polymer polyol, such as a polyether polyol or by in situ reaction between a polyisocyanate and an amino-functional compound or a hydroxy-functional compound, such as triethanolamine, in a polymer polyol. In one preferred embodiment, the CPP product can include a product obtained by in situ polymerization of styrene and / or acrylonitrile in a polyoxyethylene polyoxypropylene polyol and / or a product obtained by in situ reaction between a polyisocyanate and an amino-functional compound or a hydroxy-functional compound (such as triethanolamine) in a polyoxyethylene polyoxypropylene polyol. In one preferred embodiment, the CPP product can include a product obtained by in situ polymerization of styrene and / or acrylonitrile in a polyoxyethylene polyoxypropylene polyol and / or a product obtained by in situ reaction between a polyisocyanate and an amino-functional compound or a hydroxy-functional compound (such as triethanolamine) in a polyoxyethylene polyoxypropylene polyol. and / or a product obtained by in situ reaction between a polyisocyanate and an amino-functional compound or a hydroxy-functional compound (such as triethanolamine) in a polyoxyethylene polyoxypropylene polyol. and / or a product obtained by in situ reaction between a polyisocyanate and an amino-functional compound or a hydroxy-functional compound (such as triethanolamine) in a polyoxyethylene polyoxypropylene polyol. and / or a product obtained by in situ reaction between a polyisocyanate and an amino-functional compound or a hydroxy-functional compound (such as triethanolamine) in a polyoxyethylene polyoxypropylene polyol. This can include products obtained by in situ reaction between a polyisocyanate and an amino-functional compound or a hydroxy-functional compound (such as triethanolamine) in a polyoxyethylene polyoxypropylene polyol.

[0047] Stability is an important characteristic of polymer polyols. The dispersed phase is the polymer polyol When stored, transported, and used, it must remain distributed in the polyol phase for a long time. In addition, the polymer polyol product is often subject to large temperature fluctuations during storage and transportation and must remain stable over the entire temperature range. If the dispersion is unstable, some or all of the dispersed polymer phase may settle. This leads to fouling of transportation, storage, and processing equipment, inconsistencies in the polymer polyol product, as well as inconsistencies in the polyurethane made from the polymer polyol.

[0048] Stability is improved by using stabilizers. Stabilizers contain polyol-soluble groups and typically a polyether chain that can have a molecular weight of up to several thousand. The stabilizer is present on the surface of the dispersed polymer particles, and it is thought that the polyol-soluble groups stabilize the particles through their interaction with the continuous polyol phase. One common type of stabilizer is a "macromer" compound, typically a polyether polyol in which one or more of the hydroxyl groups are capped with a group containing polymerizable unsaturation. This type of stabilizer copolymerizes with styrene and acrylonitrile, and in so doing introduces the polyol-soluble portion into the copolymer particles. In some cases, the macromer is partially homopolymerized or copolymerized with a small amount of one or more other monomers to form a preformed stabilizer. Examples of this type of macromer and preformed stabilizer are, for example, U.S. Patent Nos. 4,513,124, 4,588,830, 4 ,640,935, 4,745,153, 4,997,957, 5, ,640,935, 4,745,153, 4,997,957, 5, No. 081,180, No. 5,196,476, No. 5,854,386, No. 5,9 90,185, No. 6,013,731, No. 6,613,827, No. 7,16 0,975, No. 7,179,882, No. 7,759,427, and No. 7, 776,969, U.S. Patent Application Publication No. US2004 - 0266958, No. US20 05 - 0085613, No. US2007 - 0060690, and No. US200 9 - 0281206, EP0786480, EP1,675,885, and WO2009 / 155427.

[0049] Polyether polyols include, for example, polymers such as propylene oxide, ethylene oxide, 1 ,2 - butylene oxide, tetramethylene oxide, their blocks and / or random copolymers. Polyether polyols may contain low levels of terminal unsaturation (e.g., less than 0.02 meq / g or less than 0.01 meq / g ). Examples of such low - unsaturation polyether polyols include, for example, those prepared using so - called double metal cyanide (DMC) catalysts as described in U.S. Patent Nos. 3,27 8,457, 3,278,458, 3,278,459, 3,404 ,109, 3,427,256, 3,327,334, and 3,4 27,335.

[0050] In addition to polyols, low - molecular - weight monomers, and stabilizers, various other components may be present during the production process of polymer polyols. A polymerization catalyst is preferably present. The polymerization catalyst preferably generates free radicals under the conditions of the polymerization process. The free - radical catalyst​ It is an initiator. Examples of suitable free radical initiators include peroxy compounds such as peroxides, persulfates, perborates , percarbonates, azo compounds, etc. Specific examples of free radical initiators include hydrogen peroxide, di(decanoyl) peroxide, dilauroyl peroxide , t-butyl perneodecanoate, 1,1-dimethyl-3-hydroxybutyl peroxide -2-ethylhexanoate, di(t-butyl) peroxide, t-butyl peroxydiethylacetate , t-butyl peroctoate, t-butyl peroxyisobutyrate , t-butyl peroxy-3,5,5-trimethylhexanoate, t-butyl perbenzoate , t-butyl peroxypivalate, t-amyl peroxypivalate, t-butyl per oxy-2-ethylhexanoate, lauroyl peroxide, cumene hydroperoxide , t-butyl hydroperoxide, azobis(isobutyronitrile), 2,2’-a zobis(2-methylbutyronitrile), etc. Two or more catalysts can be used. The amount of the catalyst can be in the range of 0.01 weight percent (wt%) to 5 wt%, preferably in the range of 0.01 wt% to 3 wt%, based on the weight of the low molecular weight monomer.

[0051] Molecular weight regulators such as chain transfer agents are another useful component. Examples of these include isopropanol, ethanol, t-butanol, toluene, ethylbenzene, trimethyl amine and other low molecular weight aliphatic alcohols, dodecyl mercaptan and octadecyl mercap tan and other mercaptans, and carbon tetrachloride, chloroform, methylene chloride and other halogenated alkanes, etc. These chain transfer agents are typically based on the low molecular weight monomer Based on weight, it is present in an amount ranging from 0.01% to 3% by weight, preferably from 0.25% to 2% by weight (when not used at all). (when not used at all).

[0052] The polymerization can be carried out continuously or in various batch and semi-batch processes. The continuous process is characterized by the continuous introduction of polyol, stabilizer, and low molecular weight monomer into the polymerization, as well as the continuous removal of the product. In the semi-batch process, at least a part of the low molecular weight monomer is introduced continuously or intermittently into the polymerization, but the product is not continuously recovered and is preferably not removed until the polymerization is complete. In the semi-batch process, a part or all of the polyol and / or stabilizer can be added continuously or intermittently during the process. Alternatively, the entire amount of these materials can be charged into the polymerization apparatus before the start of the polymerization. In the batch process, all the polyol, stabilizer, and low molecular weight monomer are charged at the start of the polymerization, and the product is not removed until the polymerization is complete. The continuous process is characterized by the continuous introduction of polyol, stabilizer, and low molecular weight monomer into the polymerization, as well as the continuous removal of the product. The semi-batch process is characterized by the continuous or intermittent introduction of at least a part of the low molecular weight monomer into the polymerization, but the product is not continuously recovered and is preferably not removed until the polymerization is complete. In the semi-batch process, at least a part of the low molecular weight monomer is introduced continuously or intermittently into the polymerization, but the product is not continuously recovered and is preferably not removed until the polymerization is complete. In the semi-batch process, the product is not continuously recovered and is preferably not removed until the polymerization is complete. In the semi-batch process, a part or all of the polyol and / or stabilizer can be added continuously or intermittently during the process. Alternatively, the entire amount of these materials can be charged into the polymerization apparatus before the start of the polymerization. In the batch process, all the polyol, stabilizer, and low molecular weight monomer are charged at the start of the polymerization, and the product is not removed until the polymerization is complete. In the batch process, all the polyol, stabilizer, and low molecular weight monomer are charged at the start of the polymerization, and the product is not removed until the polymerization is complete.

[0053] The process further includes mixing the above CPP reaction product with an isocyanate reaction product to produce a polyurethane foam forming reaction mixture composition using the CPP reaction product produced as described above. Next, the reaction mixture is used in a process to produce polyurethane foam articles according to reaction schemes known in foam production techniques. For example, when preparing a flexible polyurethane foam article or product, the A-side material and the B-side material are first prepared. Then, the A-side material and the B-side material are mixed together to form a polyurethane foam forming reaction mixture. Then, the reactive blend is subjected to the reaction using the CPP reaction product produced as described above to produce a polyurethane foam forming reaction mixture composition. Next, the reaction mixture is used in a process to produce polyurethane foam articles according to reaction schemes known in foam production techniques. For example, when preparing a flexible polyurethane foam article or product, the A-side material and the B-side material are first prepared. Then, the A-side material and the B-side material are mixed together to form a polyurethane foam forming reaction mixture. Then, the A-side material and the B-side material are mixed together to form a polyurethane foam forming reaction mixture. Next, the reactive blend is subjected to the reaction and subjecting the reactive blend to conditions sufficient to cure the flexible polyurethane foam. The A-side material is made up of at least one isocyanate-containing material (e.g., 2,4- and / or or 2,6-toluene diisocyanate (TDI), diphenylmethane diisocyanate Side B materials may include methyl disodium EDTA (MDI), as well as various isomers or derivatives of MDI. The material can include at least one of the CPP products described above.

[0054] Generally, the CPP reactant product is, for example, a polymer polyol, e.g., a polyether. One or more vinyl monomers in the vinyl polyol (e.g., styrene and acrylonitrile) by in situ polymerization of polyisocyanates in polymer polyols or with an amino- or hydroxy-functional compound such as triethanolamine The present invention can include a product obtained by an in situ reaction between In the CPP reaction product, The product obtained by in situ polymerization of styrene and / or acrylonitrile and polyisocyanate in polyoxyethylene polyoxypropylene polyol. and an amino- or hydroxy-functional compound (e.g., triethanolamine) and a product obtained by an in situ reaction between

[0055] Other optional additives or compounds may be added to the A-side material, the B-side material, or the A-side material and For example, the optional compound may be added to at least one of the B-side materials. at least one reactive catalyst; at least one surfactant; a medium such as water; and can include mixtures thereof.

[0056] Any of the known blowing agents conventionally used in the production of polyurethane foams can be used. Suitable blowing agents include water, low molecular weight halogenated hydrocarbons, carbon dioxide, and low boiling point hydrocarbons. The blowing agent is used in an amount known to those skilled in the art of foam production.

[0057] In addition to the above materials, any number of various additives conventionally used in the production of polyurethane foams, such as flame retardants, antifoaming agents, antioxidants, mold release agents, dyes, pigments, and fillers, can also be used in the process of the present invention. The above additives are used in an amount known to those skilled in the art of foam production.

[0058] The flexible polyurethane foam prepared from the above polyurethane foam-forming reaction mixture composition can be formed into foam articles or products using molding processes known to those skilled in the art. The foam-forming composition and the foams produced from such compositions can be used in a variety of applications, such as mattresses, furniture cushions, automotive seats, bumper pads, sports equipment and medical devices, helmet liners, pilot seats, earplugs, and other packaging, seats, and other shock-absorbing applications, as well as a variety of other uses.

Examples

[0059] The following examples, presented as either Invention Example (Inv.Ex.) or Comparative Example (Comp.Ex.), are provided to further illustrate the present invention, but the scope of the claims It should not be construed as limiting the enclosure. All parts and percentages are by weight unless otherwise indicated. Unless otherwise indicated.

[0060] Example 1 - Separation of Monomers and Solvents Using Extractive Distillation In an acrylonitrile - styrene CPP plant, typically, the components stripped from the CPP are collected in a waste tank and discarded. The disposal operation of the waste stream throughout the manufacturing plant alone can be costly. Therefore, it would be advantageous for the industry to recover the monomers for recycling. In an acrylonitrile - styrene CPP plant, typically, the components stripped from the CPP are collected in a waste tank and discarded. The disposal operation of the waste stream throughout the manufacturing plant alone can be costly. Therefore, it would be advantageous for the industry to recover the monomers for recycling. In an acrylonitrile - styrene CPP plant, typically, the components stripped from the CPP are collected in a waste tank and discarded. The disposal operation of the waste stream throughout the manufacturing plant alone can be costly. Therefore, it would be advantageous for the industry to recover the monomers for recycling. In an acrylonitrile - styrene CPP plant, typically, the components stripped from the CPP are collected in a waste tank and discarded. The disposal operation of the waste stream throughout the manufacturing plant alone can be costly. Therefore, it would be advantageous for the industry to recover the monomers for recycling.

[0061] This Example 1 is a simulation example that simulates a waste stream containing various monomer and solvent components processed in the separation and recovery system process shown in FIG. 8. The composition of the waste stream is shown in Table I. Using the schematic process flow sheet shown in FIG. 8, monomers (acrylonitrile, styrene) and solvents (toluene) are separated from the waste stream. The recovered monomer and solvent components are recycled back to the reaction system of the CPP production process (see FIG. 2), and the unwanted impurities are separated and discarded. In this Simulation Example 1, except for styrene with a recovery rate of approximately (~) 86%, the purity of each of the recovered streams is > 98%, and the recovery rate is > 95%. This Example 1 is a simulation example that simulates a waste stream containing various monomer and solvent components processed in the separation and recovery system process shown in FIG. 8. The composition of the waste stream is shown in Table I. Using the schematic process flow sheet shown in FIG. 8, monomers (acrylonitrile, styrene) and solvents (toluene) are separated from the waste stream. The recovered monomer and solvent components are recycled back to the reaction system of the CPP production process (see FIG. 2), and the unwanted impurities are separated and discarded. In this Simulation Example 1, except for styrene with a recovery rate of approximately (~) 86%, the purity of each of the recovered streams is > 98%, and the recovery rate is > 95%. This Example 1 is a simulation example that simulates a waste stream containing various monomer and solvent components processed in the separation and recovery system process shown in FIG. 8. The composition of the waste stream is shown in Table I. Using the schematic process flow sheet shown in FIG. 8, monomers (acrylonitrile, styrene) and solvents (toluene) are separated from the waste stream. The recovered monomer and solvent components are recycled back to the reaction system of the CPP production process (see FIG. 2), and the unwanted impurities are separated and discarded. In this Simulation Example 1, except for styrene with a recovery rate of approximately (~) 86%, the purity of each of the recovered streams is > 98%, and the recovery rate is > 95%. This Example 1 is a simulation example that simulates a waste stream containing various monomer and solvent components processed in the separation and recovery system process shown in FIG. 8. The composition of the waste stream is shown in Table I. Using the schematic process flow sheet shown in FIG. 8, monomers (acrylonitrile, styrene) and solvents (toluene) are separated from the waste stream. The recovered monomer and solvent components are recycled back to the reaction system of the CPP production process (see FIG. 2), and the unwanted impurities are separated and discarded. In this Simulation Example 1, except for styrene with a recovery rate of approximately (~) 86%, the purity of each of the recovered streams is > 98%, and the recovery rate is > 95%. This Example 1 is a simulation example that simulates a waste stream containing various monomer and solvent components processed in the separation and recovery system process shown in FIG. 8. The composition of the waste stream is shown in Table I. Using the schematic process flow sheet shown in FIG. 8, monomers (acrylonitrile, styrene) and solvents (toluene) are separated from the waste stream. The recovered monomer and solvent components are recycled back to the reaction system of the CPP production process (see FIG. 2), and the unwanted impurities are separated and discarded. In this Simulation Example 1, except for styrene with a recovery rate of approximately (~) 86%, the purity of each of the recovered streams is > 98%, and the recovery rate is > 95%. This Example 1 is a simulation example that simulates a waste stream containing various monomer and solvent components processed in the separation and recovery system process shown in FIG. 8. The composition of the waste stream is shown in Table I. Using the schematic process flow sheet shown in FIG. 8, monomers (acrylonitrile, styrene) and solvents (toluene) are separated from the waste stream. The recovered monomer and solvent components are recycled back to the reaction system of the CPP production process (see FIG. 2), and the unwanted impurities are separated and discarded. In this Simulation Example 1, except for styrene with a recovery rate of approximately (~) 86%, the purity of each of the recovered streams is > 98%, and the recovery rate is > 95%. This Example 1 is a simulation example that simulates a waste stream containing various monomer and solvent components processed in the separation and recovery system process shown in FIG. 8. The composition of the waste stream is shown in Table I. Using the schematic process flow sheet shown in FIG. 8, monomers (acrylonitrile, styrene) and solvents (toluene) are separated from the waste stream. The recovered monomer and solvent components are recycled back to the reaction system of the CPP production process (see FIG. 2), and the unwanted impurities are separated and discarded. In this Simulation Example 1, except for styrene with a recovery rate of approximately (~) 86%, the purity of each of the recovered streams is > 98%, and the recovery rate is > 95%. This Example 1 is a simulation example that simulates a waste stream containing various monomer and solvent components processed in the separation and recovery system process shown in FIG. 8. The composition of the waste stream is shown in Table I. Using the schematic process flow sheet shown in FIG. 8, monomers (acrylonitrile, styrene) and solvents (toluene) are separated from the waste stream. The recovered monomer and solvent components are recycled back to the reaction system of the CPP production process (see FIG. 2), and the unwanted impurities are separated and discarded. In this Simulation Example 1, except for styrene with a recovery rate of approximately (~) 86%, the purity of each of the recovered streams is > 98%, and the recovery rate is > 95%. This Example 1 is a simulation example that simulates a waste stream containing various monomer and solvent components processed in the separation and recovery system process shown in FIG. 8. The composition of the waste stream is shown in Table I. Using the schematic process flow sheet shown in FIG. 8, monomers (acrylonitrile, styrene) and solvents (toluene) are separated from the waste stream. The recovered monomer and solvent components are recycled back to the reaction system of the CPP production process (see FIG. 2), and the unwanted impurities are separated and discarded. In this Simulation Example 1, except for styrene with a recovery rate of approximately (~) 86%, the purity of each of the recovered streams is > 98%, and the recovery rate is > 95%.

Table 1

[0062] To generate the data described in Table I above, the Aspen process modeling tool is used to design the columns for separation. The thermodynamics that can be used in the above examples To generate the data described in Table I above, the Aspen process modeling tool is used to design the columns for separation. The thermodynamics that can be used in the above examples The learning model can be the NRTL (Non-Random Two-Liquid) theory, and any missing binary interaction parameters can be regressed by obtaining vapor-liquid equilibrium data from measured values or the literature, or can be estimated using UNIFAC (UNIQUAC Functional Group Activity Coefficient).

[0063] Other embodiments As described above, one embodiment of the present invention includes: (a) providing a waste feed stream containing monomers, solvents, and impurities; (b) subjecting the waste feed stream of step (a) to a separation process under conditions for separating monomers and solvents from the impurities in the waste stream; (c) recovering the monomers and solvents in one or more streams; and (d) moving one or more of the monomer and solvent streams from step (c) to further processing, including a process for recovering monomers and solvents present in the waste stream.

[0064] In one preferred embodiment, the waste feed stream of the above process of the present invention contains at least one solvent, at least one styrene monomer, at least one acrylonitrile monomer, ethylbenzene, heavy substances, and water.

[0065] In another preferred embodiment, step (b) of the above process includes a waste stream in which at least 30 percent of the solvent in the waste stream is removed from the waste stream, and at least 10 percent of the styrene monomer in the waste stream is removed from the waste stream, and at least ​Also, 10 percent is removed from the waste stream, and at least 90 percent of the water in the waste stream is removed. At least 90 percent is removed from the waste stream.

[0066] In yet another preferred embodiment, step (c) of the above process is such that the solvent stream removed from the waste stream is a recovered solvent stream having a purity of at least 90 percent, the styrene monomer stream removed from the waste stream is a recovered styrene monomer stream having a purity of at least 98 percent, and the acrylonitrile monomer stream removed from the waste stream is a recovered acrylonitrile stream having a purity of at least 90 percent.

[0067] As described herein, another embodiment of the present invention is (I) providing a reaction mixture of monomers in the presence of a solvent, (II) subjecting the reaction mixture of step (I) to reaction conditions to form a copolymer polyol product in combination with residual monomers, solvent, and impurities, (III) separating the copolymer polyol product from the residual monomers, solvent, and impurities to form at least a first stream of the copolymer polyol product, and at least a second stream of waste product containing residual monomers, solvent, and impurities, (IV) recovering the copolymer polyol product stream, and includes a process for producing a copolymer polyol.

[0068] One preferred embodiment of the above copolymer polyol production process further includes ( (V) In the presence of the solvent in step (I), a step of recycling the waste stream of the residual monomer, solvent, and impurities to the monomer reaction mixture is included.

[0069] Another preferred embodiment of the above copolymer polyol production process is further (V) (I) subjecting the waste feed stream from step (III) to a separation process under conditions for separating monomers and solvents from the impurities in the waste stream, and (VI) (I) a step of recovering monomers and solvents in one or more streams, and (VIII) s tep (VII) recycling one or more streams of the monomers and solvents from step (VII) to the monomer reaction mixture in the presence of the solvent in step (I).

[0070] As described herein, the present invention also includes (A) a step of feeding an azeotropic mixture of acrylonitrile and water to an extractive distillation column, and (B) a step of distilling acrylonitrile from water by extractive distillation in the extractive distillation column using an extraction solvent, and includes a process for separating acrylonitrile from water.

[0071] One preferred embodiment of the above extractive distillation process includes the use of tripropylene glycol as a solvent.

[0072] Another preferred embodiment of the above extractive distillation process includes carrying out the above extractive distillation process using an extractive distillation column where the column pressure is less than 0.15 bar and the condenser used in the column is at a temperature less than 25°C.

[0073] Yet another preferred embodiment of the above extractive distillation process is that water is 50 percent to 9 ​​​​​​​​It includes the use of an extractive distillation column for removal from an azeotropic mixture at 9 percent.

Claims

1. A process for recovering monomers and solvents present in waste streams. hand, (a) providing a waste feed stream containing monomers, solvents, and impurities; Tep and (b) converting the waste feed stream of step (a) into the subjecting the monomer and solvent to a separation process under conditions for separating the monomer and solvent from impurities. Top and (c) recovering the monomers and solvent in one or more streams; (d) mixing one or more of the monomer and solvent streams from step (c). and moving the processed data to further processing.

2. The separation process of step (b) comprises a distillation process, A combined stream is separated from the waste feed stream in the distillation process, The mixed stream of the separated monomer and solvent separated in the distillation process is 2. The process of claim 1, wherein the soluble solids are recovered in step (c).

3. The monomer and solvent mixed stream is 50 weight percent to 65 weight percent solvent, 20 weight percent to 30 weight percent styrene, 15 weight percent to 20 weight percent acrylonitrile, less than 1 weight percent water, ethylbenzene, and heavies total.

4. The separation process of step (b) comprises a first distillation process and a second distillation process. and a second distillation process in series with said first distillation process, wherein a solvent side stream is and separated from said waste feed stream in said first distillation process. The separated solvent side stream is recovered in step (c) and The mixed stream of urea and impurities is added to the waste feed stream in the first distillation process. and a mixed stream of the monomer and impurities separated in the first distillation process. The stream is recovered in step (c), and the recovered monomer and impurity mixed stream is a side stream of monomer is fed to the second separation distillation process; a second separation distillation process; The separated monomer side stream separated in the distillation process is subjected to step (c 2. The process of claim 1 , wherein the recovered

5. the waste feed stream comprising: (ai) from 20 weight percent to 60 weight percent an initial content of solvent; and (ai) 10 weight percent to 50 weight percent of styrene monomer. the initial content of .alpha.-mer; and (aiii) an initial acrylonitrile monomer content of 5 weight percent to 35 weight percent; (aiv) an initial content of ethylbenzene between 0 weight percent and 5 weight percent; (v) an initial water content of 0 weight percent to 5 weight percent; and (avi) 0 weight percent and an initial content of undesirable heavies of between 1 and 5 weight percent, ) removing the solvent, styrene monomer, and acrylonitrile from the waste feed stream; After separating at least a portion of the monomer, the waste stream separated from step (b) is (bi) a reduced solvent content of from 0 weight percent to 30 weight percent; (bii) a reduced styrene monomer content of from 0 weight percent to 25 weight percent and (biii) from 0 weight percent to 20 weight percent reduced acrylonitrile. monomer content and (biv) 0 weight percent to 3 weight percent reduced ethyl Benzene content and reduced water content (bv) of 0 to 3 weight percent (bvi) a reduced amount of undesirable substances in the range of 0 weight percent to 3 weight percent.

5. The process of claim 4, further comprising:

6. The separation process of step (b) comprises a first distillation process and a second distillation process. and a second distillation process in series with the first monomer process, wherein a side stream of the first monomer is a first distillation process for separating said waste feed stream from said waste stream; The first monomer side stream separated in the process is recovered in step (c), The second monomer, water, and solvent mixed stream is separated from the waste stream in the first distillation process. the second monomer separated in the first distillation process from the feed stream; A mixed stream of urea, water and solvent is recovered in step (c), The second mixed stream of monomer, water and solvent is fed to the second separation distillation process. and the second monomer and water mixed stream is fed to the second separation distillation process. the mixed stream of the second monomer and water is separated from the mixed stream of the first monomer and water; The solvent stream recovered in step (c) is fed to the second distillation process. The solvent stream is separated from the mixed stream and recovered in step (c). The process of claim 1.

7. The separation process of step (b) comprises a first extractive distillation process and a first extractive distillation process. and a second separate distillation process in series with the distillation process, and a stream of extractive solvent are fed to the first extractive distillation process; A stream of monomers is separated in the first extractive distillation process, and the first extractive distillation The monomer separated in step (c) is recovered and separated by a mixed stream of extraction solvent and water. The extractive solvent is separated from the water in the first extractive distillation process, and the extractive solvent and water are separated from the water in the first extractive distillation process. is recovered in step (c), and the recovered mixed stream of extraction solvent and water is the extractant stream and the water stream are fed to the second separation and distillation process; The second separation distillation process separates the extractant stream and the water stream.

2. The process of claim 1, wherein the ream is recovered in step (c).

8. of the monomer stream recovered in step (c) of the process of claim 1. and at least a portion of said solvent stream. Riolu.

9. 1. A process for producing a copolymer polyol, comprising: (I) providing a reaction mixture of monomers in the presence of a solvent, said reaction At least a portion of the monomer and at least a portion of the solvent in the mixture are The recovered monomer and recovered solvent are recovered by the process described in Steps (II) subjecting the reaction mixture of step (I) to reaction conditions to form a copolymer polyol. and forming a fluorine product.

10. 1. A process for separating acrylonitrile from water, comprising the steps of: (A) feeding an azeotropic mixture of acrylonitrile and water to an extractive distillation column; (B) extracting the acrylic acid from water by extractive distillation in the extractive distillation column using an extracting solvent; and distilling the nitrile.

Images