Method for recovering valuable components from waste fluid

Abstract

The present invention relates to a method for recovering valuable components from a waste fluid in treatment of a waste fluid generated during purification of a reaction product in a petrochemical process in which a raw material is reacted in the presence of a catalyst to produce the reaction product. The method comprises the steps of: purifying the reaction product to recover a waste fluid including an unreacted raw material, the catalyst, a material to be removed, and water, and supplying the waste fluid to a valuable component recovery tower; distilling the waste fluid in the valuable component recovery tower to recover an upper discharge stream including the unreacted raw material and the catalyst, and cooling a lower discharge stream including the material to be removed and water; and supplying the cooled lower discharge stream of the valuable component recovery tower to a layer separator to separate the lower discharge stream into a water layer and an organic layer, branching a part of the water layer to reflux same to the top of the valuable component recovery tower, and discharging the rest of the water layer.

Description

Method for recovering active components of waste fluid

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0125228 filed September 12, 2024, and all contents disclosed in the document of said Korean patent application are incorporated herein as part of this specification.

[0003] Technology field

[0004] The present application relates to a method for recovering effective components of waste fluid, and more specifically, to a method for recovering organic matter as effective components from waste fluid generated in a petrochemical process, excluding substances to be removed.

[0005] In general petrochemical processes, raw materials are reacted in the presence of a catalyst to produce reaction products, and these products are purified to produce final products. During this purification process, water and impurities contained in the raw materials, as well as organic matter generated as byproducts, are separated and treated as waste fluid.

[0006] As a representative petrochemical process, neopentyl glycol (NPG) can be produced by forming hydroxypivaldehyde (HPA) through an aldol condensation reaction of isobutylaldehyde (IBAL) and formaldehyde (FA) in the presence of a catalyst, and then proceeding with a hydrogenation reaction on the hydroxypivaldehyde. However, since the formaldehyde is used in an aqueous solution to ensure reactivity and fluidity, it contains a large amount of water, which is treated as wastewater after the aldol condensation reaction. Additionally, the formaldehyde contains trace amounts of methanol, so methanol is continuously introduced during the NPG manufacturing process, and isobutanol (i-BuOH) is generated as a byproduct of the aldol condensation reaction. These alcohols are treated as waste oil after the aldol condensation reaction.

[0007] At this time, unreacted raw materials and catalysts that were not fully separated during the purification process are introduced into the waste fluid containing the aforementioned wastewater and waste oil; however, since their boiling points are similar to methanol, which is one of the substances to be removed, there is a problem in that it is difficult to additionally recover effective components, such as unreacted raw materials and catalysts, from the waste fluid. Furthermore, the catalysts contained in the waste fluid and discarded can cause environmental pollution problems.

[0008] Therefore, there is a need to introduce a process that can further improve economic efficiency while being environmentally friendly by additionally recovering active ingredients from discarded waste fluids.

[0009] The problem to be solved in this disclosure is to provide a method for recovering effective components of waste fluid that can effectively remove substances to be removed when recovering unreacted raw materials and catalysts from discarded waste fluid, in order to solve the problem mentioned in the background technology above.

[0010] However, the problems that this disclosure aims to solve are not limited to those mentioned above, and other unmentioned problems will be clearly understood by a person skilled in the art from the description below.

[0011] According to one embodiment of the present disclosure for solving the above problem, a method for recovering an effective component from a waste fluid is provided, comprising the steps of: purifying the reaction product in a petrochemical process in which a reaction product is produced by reacting raw materials under a catalyst, thereby recovering the waste fluid containing unreacted raw materials, a catalyst, a substance to be removed, and water, and supplying the waste fluid to an effective component recovery tower; distilling the waste fluid in the effective component recovery tower to recover an upper discharge stream containing unreacted raw materials and a catalyst, and cooling a lower discharge stream containing a substance to be removed and water; and supplying the cooled lower discharge stream of the effective component recovery tower to a layer separator to separate it into a water layer and an organic layer, branching a portion of the water layer to recirculate it to the top of the effective component recovery tower, and discharging the remainder of the water layer.

[0012] According to the method for recovering active components of a waste fluid of the present disclosure, when a waste fluid comprising unreacted raw materials, a catalyst, a substance to be removed, and water is supplied to an active component recovery tower and distilled, a portion of the water discharged from the bottom of the active component recovery tower is supplied to the active component recovery tower, thereby allowing the active components (unreacted raw materials and catalyst) and the substance to be removed, which have similar boiling points, to be separated by the difference in solubility in water.

[0013] In addition, unreacted raw materials and catalysts separated in the above-mentioned active ingredient recovery tower can be recirculated to a petrochemical process and reused as raw materials. Through this, product production costs can be reduced, thereby improving the overall economic efficiency of the process and reducing environmental pollution.

[0014] The effects obtainable from the present disclosure are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art to which the present disclosure belongs from the description below.

[0015] FIG. 1 is a process flow diagram comprehensively illustrating the process of recovering an active ingredient from a waste fluid in a petrochemical process in one embodiment of the present disclosure.

[0016] FIG. 2 is a process flow diagram illustrating a method for recovering an effective component of a waste fluid according to one embodiment of the present disclosure.

[0017] FIG. 3 is a process flow diagram illustrating a method for recovering an effective component of a waste fluid according to one embodiment of the present disclosure.

[0018] Figure 4 is a process flow diagram showing a method for recovering effective components of waste fluid according to Comparative Example 1.

[0019] Figure 5 is a process flow diagram showing a method for recovering effective components of waste fluid according to Comparative Example 2.

[0020] Terms and words used in the description and claims of this disclosure shall not be interpreted as being limited to their ordinary or dictionary meanings, but shall be interpreted in a meaning and concept consistent with the technical idea of ​​this disclosure, based on the principle that the inventor may appropriately define the concept of the terms to best describe his invention.

[0021] In relation to the description of the drawings, similar reference numerals may be used for similar or related components.

[0022] The singular form of the noun corresponding to the item may include one or more of the said item unless the relevant context clearly indicates otherwise.

[0023] In the present disclosure, each of the phrases such as “A or B”, “at least one of A and B”, “at least one of A or B”, “A, B or C”, “at least one of A, B and C”, and “at least one of A, B, or C” may include any one of the items listed together in the corresponding phrase, or all possible combinations thereof.

[0024] The term “and / or” includes a combination of multiple related described components or any of the multiple related described components.

[0025] Terms such as "first," "second," or "first" or "second" may be used simply to distinguish a component from another corresponding component and do not limit the components in other aspects (e.g., importance or order).

[0026] Additionally, terms such as 'front,' 'rear,' 'top,' 'bottom,' 'side,' 'left,' 'right,' 'top,' and 'bottom' used in this disclosure are defined based on the drawings, and the shape and location of each component are not limited by these terms.

[0027] Terms such as “include” or “have” are intended to specify the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in this disclosure, and do not preclude the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0028] When it is said that one component is “connected,” “combined,” “supported,” or “in contact” with another component, this includes not only cases where the components are directly connected, combined, supported, or in contact, but also cases where they are indirectly connected, combined, supported, or in contact through a third component.

[0029] When it is said that a component is located “on” another component, this includes not only cases where one component is in contact with the other, but also cases where another component exists between the two components.

[0030] Additionally, terms such as "about," "substantially," etc., as used in this disclosure are used to mean at or near the numerical values ​​where inherent manufacturing and material tolerances are presented in the stated meanings, and are used to prevent unscrupulous infringers from unfairly exploiting the disclosed content where precise or absolute numerical values ​​are mentioned to aid in understanding this disclosure.

[0031] As used in this disclosure, the term 'stream' may refer to the flow of fluid within a process, and may also refer to the fluid itself flowing within the piping. Specifically, the stream may simultaneously refer to the fluid itself flowing within the piping connecting each device and the flow of the fluid. Additionally, the fluid may include one or more components selected from gas, liquid, and solid.

[0032] Unless otherwise specified, the term "upper" as used in this disclosure refers to a point at a height of 0% to 20% downward from the top of the device, and specifically may refer to the top (top of the tower). Additionally, the term "lower" refers to a point at a height of 80% to 100% downward from the top of the device, and specifically may refer to the bottom (bottom of the tower).

[0033] The term “pressure” as used in this disclosure refers to gauge pressure measured relative to atmospheric pressure.

[0034] Meanwhile, regarding the devices (columns) such as separation towers, extraction towers, purification towers, distillation towers, and recovery towers in the present disclosure, the operating temperature of the device may refer to the upper temperature of the device unless otherwise specified. Likewise, the operating pressure of the device may refer to the upper pressure of the device unless otherwise specified.

[0035] In describing embodiments in this specification, descriptions of technical details that are well known in the technical field to which this disclosure belongs and are not directly related to this disclosure are omitted. This is intended to convey the essence of this disclosure more clearly without obscuring it by omitting unnecessary explanations.

[0036] Hereinafter, the present disclosure will be described in more detail with reference to the drawings to facilitate understanding of the present disclosure.

[0037] The method for recovering an effective component of a waste fluid according to the present disclosure aims to efficiently remove the substance to be removed during the recovery of the effective component and catalyst by utilizing the difference in water solubility of each component when the boiling point of the effective component to be recovered is similar to the boiling point of the substance to be removed, and the boiling point of the substance to be removed is lower than the boiling point of water, in a case where the boiling point of the effective component to be recovered is similar to the boiling point of the substance to be removed.

[0038] FIGS. 1 to 3 are process flow diagrams showing a process for recovering active ingredients from waste fluid according to an embodiment of the present disclosure, illustrating a process for recovering active ingredients from waste fluid generated in a petrochemical process.

[0039] Referring to FIG. 1, the method for recovering an effective component of a waste fluid according to the present disclosure comprises a petrochemical process (100) including a reaction process and a purification process, and an effective component recovery process (300) for separating an effective component, wastewater (B), and waste oil (C) from a waste fluid (A) generated in the petrochemical process and recovering the effective component. Additionally, if necessary, a volatile organic compound separation process (200) for primarily separating a volatile organic compound and water (wastewater) from the waste fluid (A) before the effective component recovery process may be further included.

[0040] A method for recovering an effective component of a waste fluid according to one embodiment of the present disclosure comprises: (S1) a step of recovering a waste fluid containing unreacted raw material, catalyst, a substance to be removed, and water by purifying a reaction product prepared by reacting raw material under a catalyst, and supplying the waste fluid to an effective component recovery tower; (S2) a step of distilling the waste fluid in the effective component recovery tower to recover an upper discharge stream containing unreacted raw material and catalyst, and cooling a lower discharge stream containing a substance to be removed and water; and (S3) a step of supplying the cooled lower discharge stream of the effective component recovery tower to a layer separator to separate it into a water layer and an organic layer, branching a portion of the water layer to recirculate it to the top of the effective component recovery tower, and discharging the remainder of the water layer.

[0041] First, referring to FIGS. 1 and 2, waste fluid (A) is recovered from a petrochemical process (100), and said waste fluid is supplied to an effective component recovery tower (300) (S1).

[0042] The waste fluid (A) recovered from the above petrochemical process (100) includes wastewater (B) and waste oil (C), and specifically, may include unreacted raw materials, a catalyst, a substance to be removed, and water. For example, the waste fluid (A) supplied to the above effective component recovery tower (300) may include, with respect to the total weight flow rate, 0.1% to 10% by weight of unreacted raw materials, 0.1% to 10% by weight of catalyst, 40% to 75% by weight of a substance to be removed, and 20% to 50% by weight of water.

[0043] Here, the substance to be removed includes water-miscible compounds having miscibility with water, such as methanol, and may further include other reaction by-products generated in petrochemical processes. In addition, the water-miscible compound may have a boiling point lower than that of water, i.e., a boiling point of less than 100°C, and may have a boiling point similar to that of the unreacted raw material; for example, the difference in boiling point with the unreacted raw material may be -10°C to 10°C, more specifically -5°C to 5°C, and more specifically -1°C to 1°C. In addition, the boiling point of the substance to be removed may also be similar to that of the catalyst; for example, the difference in boiling point with the catalyst may be -10°C to 10°C, where the boiling point of the catalyst may refer to the boiling point when in an azeotropic state with water.

[0044] The above unreacted raw material and catalyst may each be compounds having relatively low solubility in water, for example, solubility in 100 g of water at 20°C (i.e., the limit of dissolution in 100 g of water at 20°C) may be 10 g or less, specifically 9 g or less, and more specifically 8 g or less. In addition, it is preferable that the boiling point of the above unreacted raw material and catalyst is also lower than that of water, i.e., less than 100°C.

[0045] Meanwhile, the above petrochemical processes may include, for example, a neopentyl glycol (NPG) manufacturing process and an isopropyl alcohol (IPA) manufacturing process, and while the NPG manufacturing process is the most preferable, it is not limited thereto. For example, when waste fluid (A) is recovered from the NPG manufacturing process, the raw materials of the NPG manufacturing process may include isobutylaldehyde (IBAL) and formaldehyde (FA), the unreacted raw materials contained in the waste fluid may include IBAL, and the catalyst may include triethylamine (TEA). In addition, the substances to be removed may be reaction by-products or impurities generated in the NPG process, for example, methanol may be an impurity and isobutanol may be a reaction by-product.

[0046] The height (number of stages) at which the waste fluid (A) is supplied to the effective component recovery tower (300) can be appropriately selected according to the composition, temperature, and pressure of the waste fluid (A). For example, the waste fluid (A) may be supplied to stages of 15% to 85% of the theoretical number of stages, preferably 15% to 50%, and more preferably 15% to 40% from the top of the effective component recovery tower, but is not limited thereto. Here, "theoretical number of stages" refers to the number of virtual regions or stages in which two phases, such as gaseous and liquid phases, are in equilibrium with each other in a column such as the effective component recovery tower.

[0047] Referring to FIG. 2, the waste fluid (A) is distilled in the effective component recovery tower (300) to recover the upper discharge stream (301) containing unreacted raw materials and catalyst, and the lower discharge stream (302) containing substances to be removed and water is cooled (S2).

[0048] At this time, the operating temperature and pressure of the active ingredient recovery tower (300) may be determined according to the boiling point of the active ingredient to be recovered and the boiling point of the substance to be removed, for example, the operating temperature may be 50°C to 80°C, preferably 55°C to 75°C, more preferably 60°C to 70°C, and the operating pressure may be -0.6 kg / cm² 2 up to 3.0 kg / cm² 2 , preferably 0 kg / cm² 2 up to 2.5 kg / cm² 2 , more preferably 0.5 kg / cm² 2 Up to 2.0 kg / cm² 2 It could be.

[0049] Specifically, the waste fluid (A) can be separated in the effective component recovery tower (300) into an upper fraction containing unreacted raw materials and a catalyst, and a lower fraction containing a substance to be removed and water.

[0050] The upper fraction of the effective component recovery tower (300) contains catalysts and unreacted raw materials, and can be reused by circulating them to the petrochemical process (100) through the upper discharge stream (301) of the effective component recovery tower. For example, the upper discharge stream (301) of the effective component recovery tower can be fed into a condenser (330) and condensed, then circulated to the purification process within the petrochemical process for reuse. By recovering and reusing the unreacted raw materials and catalysts from the waste fluid in this way, it is possible to secure cost competitiveness in the process while maintaining an environmentally friendly approach.

[0051] Meanwhile, the lower fraction of the above-mentioned effective component recovery tower (300) contains water and a substance to be removed, and can separate wastewater (B) containing water and waste oil (C) containing a substance to be removed through the lower discharge stream (302) of the effective component recovery tower.

[0052] In addition, the temperature of the bottom discharge stream of the active ingredient recovery tower before cooling may be 65°C to 100°C, preferably 65°C to 95°C, and more preferably 65°C to 90°C. Furthermore, the temperature of the bottom discharge stream of the active ingredient recovery tower after cooling may be 25°C to 50°C, preferably 25°C to 45°C, and more preferably 25°C to 40°C. By satisfying the above cooling temperature range, the separation of the water layer and the organic layer in the layer separator described later can be performed smoothly.

[0053] Referring to FIG. 2, the lower discharge stream of the cooled active ingredient recovery tower is supplied to a layer separator (320) to separate it into a water layer (303) and an organic layer (304), a portion (303a) of the water layer is branched and recirculated to the upper part of the active ingredient recovery tower, and the remainder (303b) of the water layer can be discharged (S3).

[0054] By recirculating a portion (303a) of the above water layer to the upper part of the effective component recovery tower (300), the substance to be removed present in the upper fraction of the effective component recovery tower can be removed. Specifically, if the substance to be removed includes a water-miscible compound having high solubility in water, and the unreacted raw material and catalyst, which are the effective components, have low solubility in water, a portion (303a) of the above water layer can be introduced to the upper part of the effective component recovery tower (300) to dissolve the water-miscible compound in water and guide it to the lower part, thereby separating the water-miscible compound from the upper fraction of the effective component recovery tower and allowing the water-miscible compound to be discharged into the lower discharge stream (302) of the effective component recovery tower. Accordingly, the effective component recovery process according to the present disclosure may be an effective method when the unreacted raw material and catalyst have low solubility in water.

[0055] More specifically, the lower discharge stream (302) of the effective component recovery tower may be fed into a heat exchanger (310) to cool it, and the cooled lower discharge stream of the effective component recovery tower may be supplied to a layer separator (320) to separate it into a water layer (303) and an organic layer (304). Additionally, the water layer (303) may be branched so that a portion of the water layer stream (303a) is recirculated to the top of the effective component recovery tower, the remaining water layer stream (303b) is discharged as wastewater (B), and the organic layer (304) is discharged as waste oil (C). Here, the water layer (303) may contain water, and the organic layer (304) may contain a substance to be removed.

[0056] Based on 100% by weight of the total flow rate of the water layer (303) separated in the layer separator (320), the flow rate ratio of the stream branched from the water layer and recirculated to the top of the effective component recovery tower may be 80% by weight to 95% by weight, preferably 80% by weight to 90% by weight, more preferably 80% by weight to 85% by weight. When the above range is satisfied, the removal of the target substance using the difference in solubility in water may be made easier.

[0057] In addition, the temperature of some stream that is recirculated to the top of the active ingredient recovery tower after cooling may be 25°C to 50°C, preferably 25°C to 45°C, more preferably 25°C to 40°C.

[0058] Additionally, the remaining water layer (303b) of the lower discharge stream (302) of the active ingredient recovery tower that is not returned to the active ingredient recovery tower may be discharged as wastewater (B) and supplied to an evaporator and / or wastewater treatment system, and the organic layer (304) may be discharged as waste oil (C) and supplied to a waste oil treatment system.

[0059] Meanwhile, referring to FIG. 3, the step (S1) may include: purifying the reaction product to recover a first waste fluid (A1) containing unreacted raw material, catalyst, substance to be removed, and water, and supplying the first waste fluid (A1) to a volatile organic compound (VOC) separation tower (200); distilling the first waste fluid (A1) in the volatile organic compound separation tower (200) to obtain a second waste fluid (A2) containing unreacted raw material, catalyst, substance to be removed, and water as an upper discharge stream (201) and wastewater (B) containing water as a lower discharge stream (202); and supplying the second waste fluid (A2) to an effective component recovery tower (300).

[0060] First, the first waste fluid (A1) is distilled in the VOC separation tower (200) to separate the second waste fluid (A2), which contains unreacted raw materials, catalyst, methanol, butanol, and a small amount of water, into the upper fraction (201), and the wastewater (B), which contains a large amount of water, into the lower fraction (202).

[0061] At this time, the operating temperature of the VOC separation tower (200) may be 50°C or higher, 60°C or higher, or 70°C or higher, and 100°C or lower, 110°C or lower, or 120°C or lower. In addition, the operating pressure of the VOC separation tower (200) is -0.5 kg / cm² 2 Above, 0 kg / cm² 2 0.5 kg / cm² or higher 2 Above and 3 kg / cm² 2 Less than 4 kg / cm² 2 5 kg / cm² or less 2 It may be less than.

[0062] In addition, the first waste fluid (A1) may contain 0.05 to 5 weight% of unreacted raw material, 0.05 to 5 weight% of catalyst, 1 to 10 weight% of a substance to be removed, and the remainder of water, with respect to the total weight flow rate thereof. At this time, the remainder of water may be 80 weight% or more.

[0063] The upper fraction of the VOC separation tower (200) is supplied to the aforementioned effective component recovery tower (300) through the VOC separation tower upper discharge stream (201), and the VOC separation tower upper discharge stream (201) may contain unreacted raw materials, a catalyst, a substance to be removed, and evaporated water. For example, the VOC separation tower upper discharge stream (201) supplied to the effective component recovery tower (300), i.e., the second waste fluid (A2), may contain 0.1% to 10% by weight of unreacted raw materials, 0.1% to 10% by weight of a catalyst, 40% to 75% by weight of a substance to be removed, and 20% to 50% by weight of evaporated water with respect to the total weight flow rate thereof, and in some cases, may further contain the remainder of impurities.

[0064] The lower fraction of the above VOC separation tower (200) is discharged as wastewater (B) through the VOC separation tower lower discharge stream (202), and can be collected together with the wastewater discharged from the above-mentioned effective component recovery tower (300) and supplied to an evaporator and / or wastewater treatment system.

[0065] According to one embodiment of the present disclosure, wastewater (B) recovered from the remaining water layer (303b) that is not returned to the effective component recovery tower among the lower discharge stream of the effective component recovery tower (300) and the lower discharge stream (202) of the VOC separation tower can be supplied to an evaporator to remove sludge, and the upper fraction of the evaporator from which the sludge has been removed can be supplied to the wastewater treatment system to treat the wastewater. Additionally, the lower fraction of the evaporator can be supplied to a sludge dryer. The sludge contained in the lower discharge stream of the evaporator can be dried and treated as waste or burned and used as an energy source for the process.

[0066] Below, a case in which the method for recovering active ingredients from waste fluid according to the present disclosure is applied to the neopentyl glycol (NPG) manufacturing process as an example of a petrochemical process is described in more detail.

[0067] According to one embodiment, the NPG manufacturing process includes an aldol reaction process, an aldol purification process, and an NPG purification process, and may further include an extraction and extractant recovery process and a catalyst recovery process as needed.

[0068] In addition, the method for recovering active ingredients from waste fluid according to one embodiment of the present disclosure may recover waste fluid from one or more of the aldol purification process and NPG purification process, and, if necessary, may further recover waste fluid from one or more of the extractant recovery process and catalyst recovery process.

[0069] First, the aldol reaction process involves the aldol condensation reaction of formaldehyde (FA) and isobutylaldehyde (IBAL) in the presence of a catalyst to obtain a first reaction product containing hydroxypivaldehyde.

[0070] Since the above formaldehyde is used in an aqueous solution state to ensure reactivity and fluidity, it may contain a large amount of water. Such an aqueous formaldehyde solution may contain 40% to 64% by weight, more specifically 45% to 55% by weight of water, based on the total weight of the aqueous formaldehyde solution.

[0071] In addition, the above formaldehyde aqueous solution may contain trace amounts of methanol (MeOH) as an impurity. For example, the above formaldehyde aqueous solution may contain 0.5% to 5% by weight, more specifically 1% to 1.5% by weight of methanol, based on the total weight of the formaldehyde aqueous solution. As the above formaldehyde is continuously introduced into the process as a raw material for the aldol condensation reaction, the above methanol may also continuously flow into the process and accumulate, so it is necessary to remove it. However, since the boiling point of the methanol is similar to that of IBAL, which is one of the raw materials, and the catalyst described later, methanol may be reintroduced during the recovery of active ingredients from the waste fluid; however, by applying the method for recovering active ingredients from waste fluid according to the present disclosure, the active ingredients from which the methanol, which is the substance to be removed, can be recovered.

[0072] The catalyst may be an amine-based compound. For example, the catalyst may be a tertiary amine compound such as trialkylamine, for example, trimethylamine, triethylamine, tripropylamine, triisopropylamine, or tributylamine. Preferably, triethylamine (TEA), which has the highest efficiency in the aldol condensation reaction, may be used as a catalyst.

[0073] Meanwhile, when an aldol condensation reaction between an aqueous FA solution and IBAL is carried out in the presence of the catalyst, a catalyst salt and hydroxypivalaldehyde (HPA) may be produced, and isobutanol (i-BuOH) may be produced as a byproduct of the aldol condensation reaction. Specifically, the catalyst salt may be produced by the reaction of formic acid, generated from the Cannizzaro side reaction occurring during the aldol condensation reaction, with the catalyst. Additionally, hydroxypivalic acid-neopentylglycol ester (HPNE) and isobutanol (i-BuOH) may be produced as byproducts through the Tishchenko reaction, which is another side reaction of the aldol condensation reaction.

[0074] Accordingly, in the above aldol reaction process, a first reaction product comprising the catalyst salt, HPNE, and HPA can be obtained, and an aldol extraction process can be performed by contacting the first reaction product with an extractant to obtain an organic phase extractant comprising unreacted IBAL, the extractant, and HPA, and a liquid phase residue comprising the catalyst salt, and specific details are omitted.

[0075] Subsequently, an aldol purification process can be performed by distilling the extract to separate unreacted IBAL, the catalyst, HPA, the extractant, and the waste fluid, the specific details of which are omitted. The unreacted IBAL and the catalyst separated in the aldol purification process can be recirculated to the aldol reaction process for reuse, and the waste fluid recovered from the aldol purification process can be fed into the active ingredient recovery process according to the present disclosure.

[0076] Meanwhile, the above-mentioned residual liquid may perform a process of converting the catalyst salt into a catalyst, the specific details of which are omitted. Additionally, the converted catalyst may be separated into a catalyst and a waste fluid through a catalyst recovery process. The separated catalyst may be recirculated to the aldol purification process for reuse, and the waste fluid recovered from the catalyst recovery process may be fed into the effective component recovery process according to the present disclosure.

[0077] Meanwhile, the HPA separated in the above aldol purification process may undergo a hydrogenation reaction process with separately added hydrogen to obtain a second reaction product comprising NPG, a catalyst, an extractant, and HPNE, the specific details of which are omitted.

[0078] Subsequently, the second reaction product can be separated into NPG, an extractant and a catalyst, HPNE, and waste fluid through an NPG purification process. In the NPG purification process, the NPG can be obtained as a desired product, and the HPNE can be introduced into an HPNE purification process, the specific details of which are omitted. In addition, the waste fluid recovered from the NPG purification process can be introduced into an active ingredient recovery process according to the present disclosure.

[0079] In addition, the extractant and catalyst separated in the above NPG purification process can be separated into a catalyst, an extractant, and a waste fluid through an extractant recovery process. At this time, the catalyst can be introduced into an aldol purification process for reuse, and the extractant can be introduced into an aldol extraction process for reuse. Furthermore, the waste fluid recovered from the extractant recovery process can be fed into an active ingredient recovery process according to the present disclosure.

[0080] Meanwhile, in a method for recovering an active ingredient from a waste fluid according to one embodiment, the waste fluid (A) comprises wastewater (B) and waste oil (C), and includes one or more of the waste fluid recovered from the aldol purification process and the waste fluid recovered from the NPG purification process, and may further include the waste fluid recovered from the extractant recovery process and the waste fluid recovered from the catalyst recovery process as needed.

[0081] Referring to FIG. 2, the waste fluid (A) separated in a plurality of processes can be supplied to an effective component recovery tower (300). At this time, the wastewater (B) among the waste fluid (A) may be derived from water contained in the formaldehyde aqueous solution used in the aldol reaction process (1). In addition, the waste fluid (A) may contain catalyst that was not separated in the aldol purification process, unreacted IBAL, and methanol (MeOH), and may further contain isobutanol (i-BuOH), which is a reaction byproduct.

[0082] In order to recover and reuse the unreacted IBAL and catalyst, which are effective components contained in such waste fluid (A), it is necessary to remove MeOH and i-BuOH contained in the organic components within the waste fluid. However, the boiling point of methanol (64.5°C) is similar to the boiling point of IBAL (63.9°C), and furthermore, it is similar to the boiling point of the catalyst (TEA) when in an azeotropic state with water (70.0°C), so there is a problem in that separation is difficult using a general distillation method. Accordingly, through the method for recovering effective components of waste fluid according to the present disclosure, the unreacted IBAL and catalyst, which are effective components contained in the waste fluid, are separated from methanol, which is an impurity, and reused.

[0083] Referring to FIG. 2, the waste fluid (A) recovered from the NPG manufacturing process described above can be supplied to an effective component recovery tower (300) to perform an effective component recovery process.

[0084] Specifically, the active ingredient recovery process may separate the waste fluid (A) in the active ingredient recovery tower (300) into an upper fraction containing unreacted IBAL and a catalyst and a lower fraction containing methanol, isobutanol, and water. At this time, the operating temperature of the active ingredient recovery tower (300) may be 50°C to 80°C, and the operating pressure may be -0.6 kg / cm² 2 up to 3.0 kg / cm² 2 It could be.

[0085] The waste fluid (A) supplied to the active ingredient recovery tower (300) may contain, with respect to the total weight flow rate, 0.1% to 10% by weight of IBAL, 0.1% to 10% by weight of TEA, 15% to 30% by weight of methanol, 25% to 50% by weight of isobutanol, and 20% to 50% by weight of water.

[0086] The lower fraction of the above-mentioned active ingredient recovery tower (300) contains water, methanol, and isobutanol, and can separate and discharge wastewater (B) and waste oil (C) through the lower discharge stream (302) of the active ingredient recovery tower. The waste oil (C) contains methanol and isobutanol, and the wastewater (B) may contain water.

[0087] Additionally, referring to FIG. 2, the lower discharge stream (302) of the active ingredient recovery tower may be cooled and then supplied to a layer separator (320) to separate it into a water layer (303) and an organic layer (304), and a portion (303a) of the water layer may be recirculated to the upper part of the active ingredient recovery tower (300). By recirculating a portion (303a) of the water layer to the upper part of the active ingredient recovery tower (300), methanol present in the upper fraction of the active ingredient recovery tower may be removed. Specifically, methanol has high solubility in water, whereas the active ingredients, such as catalyst and IBAL, have low solubility in water. Accordingly, a portion (303a) of the water layer may be introduced into the upper part of the active ingredient recovery tower (300) to dissolve the methanol, thereby separating the upper fraction of the active ingredient recovery tower from the methanol and allowing the methanol to be discharged into the lower discharge stream (302) of the active ingredient recovery tower.

[0088] More specifically, referring to FIG. 2, the lower discharge stream (302) of the effective component recovery tower may be fed into a heat exchanger (310) to cool it, and the cooled lower discharge stream of the effective component recovery tower may be supplied to a layer separator (320) to separate it into a water layer (303) and an organic layer (304). Additionally, the water layer (303) may be branched so that a portion of the stream (303a) is recirculated to the top of the effective component recovery tower, the remaining stream (303b) is discharged as wastewater (B), and the organic layer (304) is discharged as waste oil (C). Here, the water layer (303) may contain water and methanol, and the organic layer (304) may contain methanol and isobutanol.

[0089] For example, based on 100% by weight of the total flow rate of the above water layer (303), the flow rate ratio of the stream (303a) branched from the water layer and recirculated to the top of the effective component recovery tower may be 0.5% by weight to 20% by weight, preferably 1% by weight to 15% by weight, more preferably 5% by weight to 10% by weight. When the above range is satisfied, energy efficiency can be increased while sufficiently securing methanol removal performance.

[0090] Meanwhile, the upper fraction of the active ingredient recovery tower (300) contains a catalyst and IBAL, and can be reused by circulating it to one or more processes among the aldol reaction process and the aldol purification process through the upper discharge stream (301) of the active ingredient recovery tower. For example, the upper discharge stream (301) of the active ingredient recovery tower (300) can be fed into a condenser (330) and circulated to one or more processes among the aldol reaction process and the aldol purification process in a condensed state. By recovering and reusing the catalyst and unreacted IBAL in this way, NO by the catalyst x By reducing the generation of [products], it is possible to secure cost competitiveness in the process while being eco-friendly.

[0091] Meanwhile, the above waste fluid (A) may be introduced into the VOC separation tower (200) first before being supplied to the effective component recovery tower (300).

[0092] Referring to FIG. 3, a first waste fluid (A1) can be distilled in the VOC separation tower (200) to separate a second waste fluid (A2) containing a catalyst, IBAL, methanol, butanol, and a trace amount of water into an upper fraction (201), and wastewater (B) containing a large amount of water into a lower fraction (202). At this time, the operating temperature of the VOC separation tower (200) may be 60°C to 100°C, and the operating pressure may be -0.5 kg / cm² 2 up to 3.0 kg / cm² 2It may be. In addition, the first waste fluid (A1) may contain, with respect to the total weight flow rate, 0.05% to 0.5% by weight of IBAL, 0.05% to 0.5% by weight of TEA, 1% to 10% by weight of methanol, 1% to 5% by weight of isobutanol, and the remainder of water (e.g., 80% by weight or more).

[0093] The upper fraction of the VOC separation tower (200) is supplied to the aforementioned effective component recovery tower (300) through the VOC separation tower upper discharge stream (201), and the VOC separation tower upper discharge stream (201) may contain a catalyst, unreacted IBAL, methanol, isobutanol, and evaporated water. For example, the VOC separation tower upper discharge stream (201) supplied to the effective component recovery tower (300), i.e., the second waste fluid (A2), may contain 0.1% to 10% by weight of IBAL, 0.1% to 10% by weight of catalyst, 15% to 30% by weight of methanol, 25% to 50% by weight of isobutanol, and 20% to 50% by weight of evaporated water with respect to the total weight flow rate thereof, and in some cases, may further contain the remainder of impurities.

[0094] Meanwhile, the lower fraction of the VOC separation tower (200) can be supplied to an evaporator and / or wastewater treatment system through the VOC separation tower lower discharge stream (202).

[0095] In a method for recovering an effective component of a waste fluid according to one embodiment of the present disclosure, additional devices such as a distillation column, a condenser, a reboiler, a valve, a pump, a separator, and a mixer may be installed if necessary.

[0096] Although the method for recovering effective components of waste fluid according to the present disclosure has been described and illustrated in the drawings above, the description and drawings above describe and illustrate only the essential components for understanding the present disclosure. In addition to the processes and devices described and illustrated above, processes and devices not separately described and illustrated may be appropriately applied and utilized to implement the method for recovering effective components of waste fluid according to the present disclosure.

[0097] The present disclosure will be explained in more detail below through examples. However, the following examples are intended to explain the present disclosure more specifically, and the scope of the present disclosure is not limited by the following examples.

[0098] [Example]

[0099] Example 1

[0100] According to the process flow shown in Figure 2, a process for recovering an active ingredient from waste fluid recovered in the neopentyl glycol (NPG) manufacturing process was simulated using Aspen's Aspen Plus simulator.

[0101] Specifically, waste fluid (A) was recovered from the catalyst recovery process, aldol purification process, neopentyl glycol purification process, and extractant recovery process during the neopentyl glycol (NPG) manufacturing process, and then supplied to an active ingredient recovery tower (300). In the active ingredient recovery tower (300), an upper fraction containing catalyst and IBAL and a lower fraction containing isobutanol, methanol, and water were separated. At this time, the operating temperature of the active ingredient recovery tower (300) was 58℃, and the operating pressure was -0.55 kg / cm² 2 was.

[0102] The upper fraction of the active ingredient recovery tower was condensed in a condenser (33) through the active ingredient recovery tower upper discharge stream (301) and then circulated to the aldol refining process. Additionally, the lower fraction of the active ingredient recovery tower was cooled in a heat exchanger (310) through the active ingredient recovery tower lower discharge stream (302) and then supplied to a layer separator (320). The cooled active ingredient recovery tower lower discharge stream was separated into a water layer (303) and an organic layer (304) through the layer separator (320). The water layer (303) was divided into a weight flow rate ratio of 20:80, so that a first water layer stream (303a) with a flow rate of 20% was recirculated to the upper part of the active ingredient recovery tower, a second water layer stream (303b) with a flow rate of 80% was discharged as wastewater (B), and the organic layer (304) was discharged as waste oil (C).

[0103] Comparative Example 1

[0104] Comparative Example 1 did not have an active ingredient recovery tower, so it did not perform a process to separate the active ingredient catalyst, unreacted IBAL, and methanol from the waste fluid recovered from the neopentyl glycol (NPG) manufacturing process.

[0105] Comparative Example 2

[0106] According to the process flow shown in Fig. 4, a process for recovering an active ingredient from waste fluid recovered in the neopentyl glycol (NPG) manufacturing process was simulated using Aspen's Aspen Plus simulator.

[0107] Specifically, Comparative Example 2 condensed the upper fraction of the effective component recovery tower (300) through the effective component recovery tower upper discharge stream (301) into a condenser (330), then branched at a weight flow rate ratio of 20:80, so that the first stream (301a) with a flow rate of 20% was recirculated to the upper part of the effective component recovery tower (300), and the remaining 80% flow rate of the second stream (303b) was circulated to the aldol purification process. Additionally, the lower fraction of the effective component recovery tower (300) was cooled through the effective component recovery tower lower discharge stream (302) into a heat exchanger (310), then separated into a water layer (303) and an organic layer (304) in a layer separator (320) and discharged as wastewater (B) and waste oil (C), respectively, and the effective component recovery process was performed under the same process conditions as Example 1.

[0108] Comparative Example 3

[0109] According to the process flow illustrated in Fig. 5, a process for recovering an active ingredient from waste fluid recovered in the neopentyl glycol (NPG) manufacturing process was simulated using Aspen's Aspen Plus simulator.

[0110] Comparative Example 3 performed an effective component recovery process under the same process conditions as Example 1, except that the lower fraction of the effective component recovery tower was cooled to a heat exchanger (310) through the effective component recovery tower lower discharge stream (302), separated into a water layer (303) and an organic layer (304) in a layer separator (320), and the organic layer (304) was branched at a weight flow rate ratio of 20:80, so that a first organic layer stream (304a) with a flow rate of 20% was recirculated to the top of the effective component recovery tower, and the remaining 80% flow rate of a second organic layer stream (304b) was discharged as waste oil (C).

[0111] [Experimental Example]

[0112] Table 1 below shows the recovery rate of active ingredients (IBAL and TEA) and the methanol removal rate of the examples and comparative examples.

[0113] Specifically, the IBAL recovery rate (%) is calculated based on the total weight of IBAL in the upper discharge stream of the effective component recovery tower (301 in FIG. 2 for Example 1, 301b in FIG. 4 for Comparative Example 2, and 301 in FIG. 5 for Comparative Example 3) relative to the total weight of IBAL in the upper discharge stream (201) of the VOC separation tower.

[0114] The TEA recovery rate (%) is calculated based on the total weight of TEA in the upper discharge stream of the effective component recovery tower (301 in FIG. 2 for Example 1, 301b in FIG. 4 for Comparative Example 2, and 301 in FIG. 5 for Comparative Example 3) relative to the total weight of TEA in the upper discharge stream (201) of the VOC separation tower.

[0115] Meanwhile, the methanol removal rate (%) is calculated by comparing the total weight ratio of MeOH reduced in the upper discharge stream of the effective component recovery tower (301 in FIG. 2 for Example 1, 301b in FIG. 4 for Comparative Example 2, and 301 in FIG. 5 for Comparative Example 3) to the total weight ratio of MeOH in the upper discharge stream (201) of the VOC separation tower.

[0116] Classification Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 IBA Recovery Rate (%) 88.24 088.24 89.08 TEA Recovery Rate (%) 70.12 054.55 30.58 MeOH Removal Rate (%) 3.60 0.92.7

[0117] Referring to Table 1 above, when a separation process is performed by additionally providing an effective component recovery tower for waste oil separated from waste fluid through a VOC separation tower, the IBAL recovery rate was similar in all cases, but in the case of Example 1, in which a portion of the water layer of the lower discharge stream (302) of the effective component recovery tower was recirculated to the upper part of the effective component recovery tower, it was confirmed that the TEA recovery rate and MeOH removal rate were significantly improved.

[0118] Although exemplary embodiments of the present disclosure have been described above, the present disclosure is not limited thereto, and those skilled in the art will understand that various changes and modifications are possible within the scope and concept of the claims set forth below.

[0119] [Explanation of the symbol]

[0120] 100: Petrochemical processes (reaction and refining processes)

[0121] 200: Volatile Organic Compound Separation Process (VOC Separation Tower)

[0122] 300: Active ingredient recovery process (active ingredient recovery tower)

[0123] 310: Heat exchanger

[0124] 320: Layer separator

[0125] 330: Condenser

[0126] A: Waste fluid

[0127] B: Wastewater

[0128] C: Waste oil

Claims

1. In the treatment of waste fluid generated while purifying a reaction product in a petrochemical process in which raw materials are reacted under a catalyst to produce a reaction product, (S1) A step of purifying the reaction product to recover waste fluid containing unreacted raw materials, catalyst, substances to be removed, and water, and supplying the waste fluid to an effective component recovery tower; (S2) A step of distilling the waste fluid in the above effective component recovery tower to recover the upper discharge stream containing unreacted raw materials and catalyst, and cooling the lower discharge stream containing substances to be removed and water; and (S3) supplying the lower discharge stream of the cooled active ingredient recovery tower to a layer separator to separate it into an aqueous layer and an organic layer, branching off a portion of the aqueous layer to recirculate it to the upper part of the active ingredient recovery tower, and discharging the remainder of the aqueous layer; comprising the step of The above-mentioned substances to be removed include water-miscible compounds, and A method for recovering an effective component of a waste fluid, comprising the above-mentioned water-miscible compound having a boiling point lower than that of water and a boiling point difference of -10°C to 10°C with respect to the above-mentioned unreacted raw material.

2. In Paragraph 1, A method for recovering an effective component of a waste fluid, wherein the waste fluid supplied to the effective component recovery tower comprises, with respect to the total weight flow rate, 0.1% to 10% by weight of unreacted raw material, 0.1% to 10% by weight of catalyst, 40% to 75% by weight of substance to be removed, and 20% to 50% by weight of water.

3. In Paragraph 1, The above (S1) step is, A step of purifying the above reaction product to recover a first waste fluid containing unreacted raw materials, a catalyst, a substance to be removed, and water, and supplying the first waste fluid to a volatile organic compound separation tower; A step of distilling the first waste fluid in the volatile organic compound separation tower to obtain a second waste fluid containing unreacted raw material, catalyst, substance to be removed, and water as an upper discharge stream, and wastewater containing water as a lower discharge stream; and A method for recovering an effective component of a waste fluid, comprising the step of supplying the above-mentioned second waste fluid to an effective component recovery tower.

4. In Paragraph 3, A method for recovering an effective component of a waste fluid, wherein the first waste fluid comprises, with respect to the total weight flow rate, 0.05 to 5 weight% of unreacted raw material, 0.05 to 5 weight% of catalyst, 1 to 10 weight% of a substance to be removed, and the remainder being water.

5. In Paragraph 3, A method for recovering an effective component of a waste fluid, wherein the second waste fluid comprises, with respect to the total weight flow rate, 0.1% to 10% by weight of unreacted raw material, 0.1% to 10% by weight of catalyst, 40% to 75% by weight of substance to be removed, and 20% to 50% by weight of evaporated water.

6. In Paragraph 1, A method for recovering effective components of waste fluid, wherein, based on 100% by weight of the total flow rate of the water layer separated in the above layer separator, the flow rate ratio of the stream branched from the water layer and recirculated to the top of the effective component recovery tower is 80% to 95% by weight.

7. In Paragraph 1, A method for recovering an effective component of waste fluid, wherein the temperature of the lower discharge stream of the effective component recovery tower before cooling is 65°C to 100°C.

8. In Paragraph 1, A method for recovering an effective component of waste fluid, wherein the temperature of a portion of the stream recirculated to the top of the effective component recovery tower is 25°C to 50°C.

9. In Paragraph 1, The above raw material includes isobutylaldehyde and formaldehyde, and The above unreacted raw material includes isobutylaldehyde, and A method for recovering an effective component of waste fluid, wherein the catalyst described above includes triethylamine.

10. In Paragraph 1, A method for recovering an effective component of waste fluid, wherein the above-mentioned water-miscible compound includes methanol.

11. In Paragraph 1, A method for recovering an effective component of waste fluid, comprising reusing the upper discharge stream of an effective component recovery tower containing unreacted raw materials and catalyst recovered in step (S2) above in the petrochemical process.

12. In Paragraph 1, The above petrochemical process is a neopentyl glycol manufacturing process, a method for recovering active ingredients from waste fluid.

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