KR101180341B1 - Reuse method by dividing of wastes in polyol production - Google Patents

Abstract

PURPOSE: A separating and regenerating method of waste generated during a production of polyol is provided to improve collecting rate of wasted polyol products, and to improve purity of a neutralizer salt. CONSTITUTION: A separating and regenerating method of waste generated during a production of polyol comprises: a step of dissolving polyol by putting acetone into a polyol waste; a step of separating polyol filtrate(the polyol and the acetone) from solid phase(a catalyst and the neutralizer) by filtering the polyol dissolved in acetone; a step of refining the polyol filtrate; a step of dissolving the catalyst by putting the solid phase and a polar solvent in; a step of separating a catalyst filtrate(the catalyst and the polar solvent) from the solid phase(the neutralizer) by filtering the catalyst dissolved in the polar solvent; a step of re-generating the catalyst by heating the catalyst filtrate; a step of regenerating neutralizing agent.

Description

Reuse method by dividing of wastes in polyol production}

The present invention relates to a method for separating and recycling waste generated during polyol production. More specifically, the waste generated when producing polyol such as polypropylene glycol (PPG) and polyalkylene glycol (PAG) is a kind of nonpolar solvent. The product is recovered by dissolving the polyol with phosphorus acetone, and extracting the catalyst dissolved in it using a polar solvent and recovering the solid neutralizer, which is generated in the process of producing polyol that can efficiently recycle the wasted waste resources. It relates to a method for separating and recycling waste.

As is well known, polyols are propylene oxide and initiators such as polyfunctional alcohols or aromatic amines having two or more hydroxyl groups (-OH) or amine groups (-NH2) in the molecule. (Propylene oxide, PO) or ethylene oxide (Ethylene oxide, EO) obtained by the reaction under appropriate conditions, a polyurethane prepared with methylene diphenyl diisocyanate (4,4'-diphenylmethane diisocyanate, MDI) It is an essential raw material for, and is used for applications such as surfactants and synthetic lubricants. Polyols are largely classified into polyether polyols and polyester polyols, and used in varying molecular weights of initiators and products, and used according to the types of initiators and alkylene oxides. A polyol product that meets the needs can be made, and the viscosity and molecular weight of the product can be controlled by adjusting the dosage of the alkylene oxide used.

On the other hand, when the polyol is produced, polyol waste is generated in the process of removing the catalyst used in the reaction process.In order to remove the catalyst used in the reaction process of the polyol, a neutralizing agent was added to the reactor and stirred, which was used in the reaction process. The catalyst is adsorbed on the surface of the neutralizer in the form of a salt to form a neutralizer salt, which is present as waste in the reactor. At this time, the polyol waste generated contains neutralizing salts adsorbed on the catalyst, and since most of the polyol waste is disposed of rather than recycled, the polyol waste generated during polyol production not only causes product loss and environmental pollution, but also wastes resources. It is the result.

Recently, there have been attempts to solve the above problems. In Korea Patent Publication No. 10-1105015 (Registration Date: 2012. 01. 04), a polyol is extracted by reacting a neutralizing salt with water, and then reacted with an alcohol to form a catalyst. Disclosed is a method for regenerating a polyol waste consisting of extracting and recovering a neutralizing agent. However, in this case, since the polyol is not easily dissolved in a polar solvent such as water, the purification rate of the polyol in water is extremely low and the purity of the neutralizing agent separated from the catalyst extracted by the polar solvent is very low. Without the process, polyol products, as well as the catalyst and the neutralizing agent has a disadvantage that is difficult to recycle.

In addition, the Republic of Korea Patent Publication No. 10-1104978 (Registration Date: 2012. 01. 04) also in the regeneration method of the polyol waste by using a polar solvent such as water in the neutralizing salt, neutralizing the catalyst adsorbed in a conventional stirring vessel The method for regenerating polyol wastes, which is characterized in that the decontamination and the polar solvent are separated into polyols, catalysts and neutralizing agents, and the neutralizing agent is recovered and then separated into polyols and sulfates using a filter, is described. The prior art also has a disadvantage in that the purity of the catalyst due to low recovery of the polyol is lowered because the solubility of the neutralizing agent in the polar solvent is low, there are many problems in commercial use.

Accordingly, the present inventors have diligently studied the polar solvents in which the polyol components present in the polyol wastes are dissolved. As a result, the polyols having hydrophobicity are particularly well dissolved in acetone (CH ₃ COCH ₃ ) solution in the non-polar solvent, and thus the polyol It has been found that the separation of the neutralizing agent salt is easy, and the present invention has been completed in view of the fact that the catalyst can be easily separated from the neutralizing agent by using the property of dissolving well in a constant polar solvent.

It is an object of the present invention to improve the recovery rate of polyol products that are discarded by dissolving the polyols with acetone, a nonpolar solvent, to recover the products in order to effectively separate the neutralizer and the catalyst from the wastes produced when the polyols are produced. This increases the purity of the neutralizing salt, which causes the polyol to be dissolved in a polar solvent, extracts and separates high-purity catalysts, and recovers solid wastes. To provide a separate regeneration method.

Another object of the present invention is not only to reduce the treatment cost and to be environmentally friendly by continuously distilling and reusing the polar solvent which dissolves the acetone and the catalyst component used in the dissolution of the polyol component during the process step, but also to the polyol component and the catalyst. And it is to provide a separation and regeneration method of waste generated in the polyol production process to facilitate the separation of the neutralizing agent.

Separation and regeneration method of waste generated in the polyol production process according to the present invention, the polyol waste containing a polyol, a catalyst, a neutralizer and acetone in a stirred container equipped with a stirrer in a volume ratio of 1: 1 to 5 times, respectively A first step of dissolving the polyol by stirring for 1 to 3 hours at a temperature of 20 to 40 ° C; A second step of separating the polyol filtrate (polyol and acetone) from the solid (catalyst and neutralizer) by passing the polyol dissolved in acetone through a filter; A third step of purifying and regenerating the polyol in the filtrate by heating the polyol filtrate passed through the filter to a temperature of 70 to 130 ° C. to distill and reuse acetone; In a stirring vessel equipped with a stirrer, any one or more polar solvents selected from solids, water, methyl alcohol, and isopropyl alcohol (IPA) remaining in the filter during the second process may be 1: 1 to 1 A fourth step of dissolving the catalyst by injecting at a volume ratio of 5 times and stirring for 1 to 3 hours at a temperature of 20 to 40 ° C .; A fifth step of separating the catalyst filtrate (catalyst and polar solvent) from the solid (neutralizing agent) remaining in the filter by passing the catalyst dissolved in the polar solvent through the filter; A sixth step of regenerating the catalyst in the filtrate by heating the catalyst filtrate passed through the filter to a temperature of 70-130 ° C. to distill and reuse the polar solvent; And a seventh step of recovering and regenerating the neutralizing agent remaining in the filter during the fifth step.

In addition, the catalyst is any one or more selected from potassium hydroxide (KOH), sodium hydroxide (NaOH), the neutralizing agent is selected from acid clay, magnesium silicate, aluminum silicate (Aluminum silicate) It is characterized in that any one or more.

In addition, the polyol purified in the third step of the present invention is 0.3 to 1.5% by weight of a neutralizing agent selected from any one or more of magnesium silicate, aluminum silicate, acidic clay, and heated to a temperature of 85 ~ 115 ℃ and filter It is characterized by regenerating the polyol by passing through to completely remove the catalyst remaining in the polyol.

In the sixth process of the present invention, in order to completely remove the polar solvent remaining in the catalyst, water is additionally mixed at a volume ratio of 1 to 3 times based on the catalyst and distilled at a temperature of 60 to 80 ° C. to regenerate the catalyst. In order to completely remove the catalyst remaining in the neutralizing agent, the seventh step is to mix water at a volume ratio of 1 to 5 times based on the neutralizing agent in a stirring vessel equipped with a stirrer and regenerate the neutralizing agent through a filter. It features.

In the process of separating and regenerating waste generated in the polyol production process of the present invention, the polyol component is dissolved by acetone solution from the waste generated when the polyol is produced to recover the product at a high concentration, thereby improving the recovery rate of the polyol and the polyol and the neutralizing agent. In addition to increasing the purity of the salt, the neutralizing agent salt can be dissolved in a polar solvent by a continuous process to easily extract high purity catalysts and recover solid wastes to efficiently recycle waste resources. By distilling and reusing the polar solvent which dissolves acetone and catalyst used in the process, the treatment cost is reduced and the environment is very friendly.

1 is a process flowchart showing a method for separating and regenerating waste generated in a polyol production process according to the present invention.

In the method of separating and regenerating waste generated in the polyol production process of the present invention, a polyol waste including a polyol, a catalyst, and a neutralizer and acetone are added at a volume ratio of 1 to 5 times, respectively, in a stirring vessel equipped with a stirrer. A first step of dissolving the polyol by stirring for 1 to 3 hours at a temperature of ˜40 ° C., a second step of separating the polyol filtrate (polyol and acetone) from the solids (catalyst and neutralizer) by passing the polyol dissolved in acetone through a filter Process, the third step of purifying and regenerating the polyol in the filtrate by distilling and reusing acetone by heating the polyol filtrate passed through the filter to a temperature of 70 ~ 130 ℃, the filter in the second step in a stirring vessel equipped with a stirrer Solids remaining in the water, and any one or more polar solvents selected from water, methyl alcohol, isopropyl alcohol (IPA), 1: 1 to 5 The fourth step of dissolving the catalyst by stirring at a volume ratio of 20 to 40 ° C. for 1 to 3 hours, and passing the catalyst dissolved in the polar solvent through a filter to remove the catalyst from the solids (neutralizing agent) remaining in the filter. A fifth step of separating the filtrate (catalyst and polar solvent), a sixth step of regenerating the catalyst in the filtrate by distilling and reusing the polar solvent by heating the passed catalyst filtrate to a temperature of 70 ~ 130 ℃, the fifth step And a seventh step of recovering and regenerating the neutralizing agent remaining in the heavy filter.

Hereinafter, a method for separating and regenerating waste generated in a polyol production process according to the present invention will be described with reference to the drawings, which can be easily carried out by one of ordinary skill in the art. It is intended to illustrate, but does not mean that the technical spirit and scope of the present invention is limited.

As shown in FIG. 1, the method for separating and regenerating waste generated in the polyol production process according to the present invention includes the first to seventh processes, and the first to third processes include the polyol regeneration process for each process sequence. Steps 4 to 6 relate to the catalyst regeneration step, and step 7 to the neutralizer regeneration step.

In the present specification, "polyol waste" refers to waste generated during polyol production, and "neutralizing agent salt" in the polyol waste refers to neutralizing waste in which the catalyst is adsorbed to the neutralizing agent in the form of salt, and "neutralizing agent" refers to polyol It is a material used to remove the catalyst that was used in the reaction process to produce.

In the first step, polyol waste containing a polyol, a catalyst, and a neutralizer and acetone are added at a volume ratio of 1 to 5 times, respectively, in a stirring vessel equipped with a stirrer, and stirred at a temperature of 20 to 40 ° C. for 1 to 3 hours. Dissolving the polyol by dissolving the polyol, the dissolution conditions for the waste put into the stirring vessel is acetone 1: 1 to 5 times the volume ratio to the polyol waste, and at a stirring speed of 20 ~ 60rpm at a temperature of less than 40 ℃ After stirring for 1-3 hours, the hydrophobic polyol is easily dissolved in acetone, which is a nonpolar solvent. The boiling point of the acetone solution is about 56 ° C. It is preferable to keep the temperature of the reaction vessel lower than this to prevent volatility of the polar solvent.

For reference, acetone is a nonpolar solvent with a slight odor and is a colorless flammable liquid with a boiling point of 56.2 ° C. Acetone can dissolve various types of fats and resins, as well as cellulose ethers, acetate celluloses, nitrocelluloses and other cellulose esters. Acetone is also used as a chemical intermediate in the manufacture of pharmaceuticals and in the manufacture of solvents such as vinyl, acrylic resins, lacquers, alkyd paints, inks, cosmetics (such as nail polish removers), varnishes, and paper coatings, adhesives and thermal adhesive coatings. It can be used as a starting material in the synthesis of various compounds.

In the second process, the polyol dissolved in acetone is passed through a filter to separate the polyol filtrate (polyol and acetone) from the solids (catalyst and neutralizer), which is generally used at a temperature of 40 ° C. or lower using a filter press. By carrying out a filtration pressure of 1 to 5 kgf / cm 2 at the temperature, the filtrate in which the polyol is dissolved is properly separated from the solids. At this time, the solids remaining in the filter consists of a catalyst and a neutralizing agent, and a catalyst and acid clay composed of potassium hydroxide (KOH), sodium hydroxide (NaOH), etc. adsorbed to the neutralizing agent to form a salt. The neutralizing agent consisting of magnesium silicate, aluminum silicate, and the like remains in the filter without being dissolved in acetone, which is a non-polar solvent, so that the polyol product can be easily extracted.

The third step is to purify and regenerate the polyol in the filtrate by heating the polyol filtrate passed through the filter to a temperature of 70 ~ 130 ℃ by distilling and reusing acetone, the filtrate passed through the filter in the second step (polyol and Acetone) is stored in a container and heated and distilled above the boiling point of acetone (56 ° C.), and the acetone is condensed by setting the temperature of the primary and secondary coolers to 35 ° C. and 20 ° C. or lower, respectively. In addition, the concentrated polyol can be produced as a purified product by completely removing the polar solvent.

In addition, the polyol purified in the third step is added to 0.3 ~ 1.5% by weight of a neutralizing agent selected from any one or more of magnesium silicate, aluminum silicate, acidic clay by a separate process and heated to a temperature of 85 ~ 115 ℃. And by passing through a filter to completely remove the catalyst remaining in the polyol can further improve the purity of the polyol product produced.

The fourth step is a solid container remaining in the filter of the second step in the stirring vessel equipped with a stirrer, any one or more polar solvents selected from water, methyl alcohol (Methyl alcohol), isopropyl alcohol (Isopropyl alcohol, IPA) 1: 1 to 5 times the volume ratio of each, and to dissolve the catalyst by stirring for 1 to 3 hours at a temperature of 20 ~ 40 ℃, under the above conditions by operating the stirring speed of the stirrer at 20 ~ 60rpm The catalyst adsorbed in the neutralizing salt, which is a solid remaining in the solution, is dissolved and extracted.

The catalyst used in the polyol waste of the present invention is generally selected from potassium hydroxide (KOH), sodium hydroxide (NaOH), and the neutralizing agent is acid clay, magnesium silicate, aluminum silicate. Since it is known, in the present invention, by using any one or more polar solvents selected from water, methyl alcohol, and IPA (Isopropyl alcohol) by using about 1 to 5 times the total volume of solids, potassium hydroxide (KOH) or By selectively dissolving the catalyst consisting of sodium hydroxide (NaOH) it is possible to easily separate the catalyst component from the neutralizing agent.

Unlike the neutralizing agent, the catalyst has a hydrophilic polar material that is well soluble in water, and these catalysts have a very high solubility in water, methyl alcohol, and IPA (Isopropyl alcohol) among polar solvents. Since the catalyst adsorbed on is a polar substance such as potassium hydroxide (KOH) and sodium hydroxide (NaOH) and is polarized by electron affinity, the catalyst can be catalyzed from neutralizing salts by utilizing the property of being easily ionized to a specific polar solvent. Only components can be dissolved in a polar solvent and separated from the neutralizing agent as a solid.

In the fifth step, the catalyst dissolved in the polar solvent is passed through a filter to separate the catalyst filtrate (catalyst and the polar solvent) from the solids (neutralizing agent) remaining in the filter, which is 40 ° C. or less using a conventional filter press. The filtrate, in which the catalyst is dissolved, is easily separated from the solids when carried out at a filtration pressure of 1 to 5 kgf / cm 2 at a temperature of. As a result, the filtrate passed through the filter is a polar solvent with the catalyst and the material remaining in the filter is a neutralizing agent.

The sixth step is to regenerate the catalyst in the filtrate by heating the catalyst filtrate through the filter to a temperature of 70 ~ 130 ℃ by distilling and reusing the polar solvent, for example, methanol as a polar solvent is a colorless liquid, boiling point Since it is 64.96 ° C., the present invention can be reused by heating and distilling at a boiling point or higher depending on the type of polar solvent such as water, methyl alcohol, isopropyl alcohol (IPA), etc., and refluxing the fourth step. do. At this time, the recovery of the polar solvent is condensed by setting the temperature of the primary and secondary coolers to 35 ° C and 20 ° C or less, respectively, and if a solvent such as methyl alcohol and IPA is used as the polar solvent, Potassium, sodium hydroxide) must be distilled only a certain amount of polar solvent in order to concentrate, so that crystallization of the catalyst does not occur, it is preferable to distill only a certain amount of the polar solvent and to distill the remaining polar solvent after adding water before the catalyst is crystallized. It was investigated due to the strong hygroscopicity of potassium hydroxide (KOH) and sodium hydroxide (NaOH) used as a catalyst.

In the sixth step, in order to completely remove the polar solvent remaining in the catalyst, water may be additionally mixed at a volume ratio of 1 to 3 times based on the catalyst and distilled at a temperature of 60 to 80 ° C. to obtain a high purity catalyst. Will be.

The seventh step is to recover and regenerate the neutralizing agent remaining in the filter during the fifth step, the neutralizing agent remaining in the filter is 50 ~ 80 ℃ in a stirring vessel equipped with a stirrer to completely remove the catalyst remaining in the neutralizing agent Add water at a temperature of about 1 to 5 times based on the neutralizing agent, and mix the mixture. Then, the neutralizing agent mixed with water is passed through the filter to completely remove the catalyst components remaining in the neutralizing agent. The high purity neutralizing agent is recovered and regenerated, which is composed of any one or more selected from acidic clay, magnesium silicate and aluminum silicate.

As described above, the present invention has been completed through numerous experiments, and the present invention selectively dissolves the polyol with acetone, which is a kind of nonpolar solvent, to recover the primary polyol product, and also recovers neutralizer waste. In order to effectively separate the neutralizing agent and the catalyst, a method of extracting the catalyst adsorbed on the neutralizing agent waste with a polar solvent and separating it from the neutralizing agent was selected. Polyols, catalysts and neutralizers separated and regenerated step by step according to the present invention are all commercialized due to their excellent purity, and the polar solvents used at the time of polyol waste separation can be recycled by recovering them during the process, which is harmful to the environment. It was set as the method of reducing the occurrence to the minimum.

Since the polyol waste regenerated by the above-mentioned method is composed of 45 to 50% by weight of polyol, 15 to 20% by weight of catalyst, and 30 to 40% by weight of neutralizing agent, respectively, it is completely dissolved in polyol by acetone solution which is a nonpolar solvent. It is confirmed that a large amount of polyol products can be recycled with high purity, thereby increasing the purity of the neutralizing salt, thereby improving the recovery composition ratio of the catalyst by 15 to 20% or more based on the total weight of the polyol waste. In addition, since the neutralizing agent can be purified into a more pure product by a separate treatment process, the present invention has a merit that the efficiency of the process is remarkably excellent compared to the conventional polyol waste treatment method.

Therefore, as described above, the method of separating and regenerating waste generated in the polyol production process is an economical and environmentally friendly process technology capable of efficiently recycling waste materials that are wasted, and by those skilled in the art without departing from the spirit of the present invention. Of course, the technical configuration can be substituted, modified, and changed by equal means.

Claims (7)

Into a stirring vessel equipped with a stirrer, polyol waste containing a polyol, a catalyst and a neutralizing agent and acetone were added at a volume ratio of 1 to 1 to 5 times, respectively, and stirred at a temperature of 20 to 40 ° C. for 1 to 3 hours to dissolve the polyol. First step to make;
A second step of separating the polyol filtrate (polyol and acetone) from the solid (catalyst and neutralizer) by passing the polyol dissolved in acetone through a filter;
A third step of purifying and regenerating the polyol in the filtrate by heating the polyol filtrate passed through the filter to a temperature of 70 to 130 ° C. to distill and reuse acetone;
In a stirring vessel equipped with a stirrer, any one or more polar solvents selected from solids, water, methyl alcohol, and isopropyl alcohol (IPA) remaining in the filter during the second process may be 1: 1 to 1 A fourth step of dissolving the catalyst by injecting at a volume ratio of 5 times and stirring for 1 to 3 hours at a temperature of 20 to 40 ° C .;
A fifth step of separating the catalyst filtrate (catalyst and polar solvent) from the solid (neutralizing agent) remaining in the filter by passing the catalyst dissolved in the polar solvent through a filter;
A sixth step of regenerating the catalyst in the filtrate by heating the catalyst filtrate passed through the filter to a temperature of 70-130 ° C. to distill and reuse the polar solvent;
A seventh step of recovering and regenerating the neutralizing agent remaining in the filter in the fifth step;
Separation and regeneration method of the waste generated in the polyol production process characterized in that comprises a. The method of claim 1,
Wherein the catalyst is potassium hydroxide (KOH), sodium hydroxide (NaOH) is any one or more selected from the polyol production process characterized in that the separation of the waste generated in the production process. The method of claim 1,
The neutralizing agent may be any one or more selected from acid clay, magnesium silicate and aluminum silicate. 4. The method according to any one of claims 1 to 3,
The polyol purified in the third step is 0.3 to 1.5% by weight of a neutralizing agent selected from any one or more of magnesium silicate, aluminum silicate, acidic clay, heated to a temperature of 85 ~ 115 ℃ and passed through a filter to remain in the polyol Separation and regeneration of the waste generated in the polyol production process, characterized in that to regenerate the polyol by completely removing the catalyst. delete 4. The method according to any one of claims 1 to 3,
In the sixth process, in order to completely remove the polar solvent remaining in the catalyst, water is additionally mixed at a volume ratio of 1 to 3 times based on the catalyst and distilled at a temperature of 60 to 80 ° C. to regenerate the catalyst. Separation and regeneration of waste from polyol production. 4. The method according to any one of claims 1 to 3,
In the seventh step, in order to completely remove the catalyst remaining in the neutralizing agent, water is mixed in a volume ratio of 1 to 5 times additionally based on the neutralizing agent in a stirring vessel equipped with a stirrer and regenerated the neutralizing agent by passing through a filter. Separation and regeneration of wastes generated in the production of polyol.

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