A recycled polyol production method using BIO-based material

Abstract

The invention relates to a sustainable, environmentally friendly recycled polyol production method using flexible polyurethane foam scraps generated during the production of flexible polyurethane foam, in order to reintegrate into the system.

Description

[0001] DESCRIPTION

[0002] A RECYCLED POLYOL PRODUCTION METHOD USING BIO-BASED

[0003] MATERIAL

[0004] Technical Field

[0005] The invention relates to a sustainable, environmentally friendly recycled polyol production method using flexible polyurethane foam scraps generated during the production of flexible polyurethane foam, in order to reintegrate into the system.

[0006] Prior Art

[0007] The recycling methods of flexible polyurethane foam at a state of the art are disclosed in the main patent application numbered 2022 / 010512. As also explained in the main patent application, in the known state of the art, waste flexible polyurethane foams can be reused by means of physical or chemical recycling methods. The advantages-disadvantages of these methods are described in detail in the main patent application.

[0008] On the other hand, base polyol which is one of the raw materials used in the main patent application numbered 2022 / 010512 is a petroleum-based polymer. Due to the petroleumbased nature of this component, it has negative environmental impacts. In the present invention, a polyol was produced by using petroleum-based base polyol and natural oil for the purpose of recovering flexible polyurethane foams. Additionally, a bio-based carbon content analysis was performed on the resulting polyol, and the result of the analysis showed a bio-based carbon content of 40%. Further studies are needed to increase the bio-based carbon content in addition to the current invention. Such improvements are highly important for contributing to sustainability, the circular economy, and reducing the carbon footprint. of the Invention

[0009] The objective of the invention is to implement a sustainable, environmentally friendly recycled polyol production method using flexible polyurethane foam scraps generated during the production of flexible polyurethane foam, in order to reintegrate such into the system.

[0010] In the invention, a polyol obtained from natural oils was used instead of petroleum-derived base polyol in order to reduce the use of petroleum-derived products. In the invention, various studies were conducted to increase the bio-based carbon content. As a result of these studies, the bio-based carbon content of the polyol produced by the method of the invention was increased. Consequently, the method of the invention contributes to sustainability and the circular economy, while also reducing the carbon footprint.

[0011] Description of the Figures:

[0012] Figure 1: It is the flow chart of the method of the invention.

[0013] Figure 2: (a) The fossil-based carbon content and the bio-based carbon content of the polyol obtained from petroleum-derived base polyol in the main patent application numbered 2022 / 010512 (b) This is a representative graphical illustration of the fossil-based carbon content and the bio-based carbon content of the polyol obtained from natural oils in the invention.

[0014] Description of the References in the Figures

[0015] In order to better understand the invention, the references in the figures are explained below:

[0016] BP- Base polyol

[0017] PUR- Polyurethane Foam Wastes

[0018] DY- Natural Oil

[0019] AN- Anhydride

[0020] A- Acidolysis

[0021] OA- Oxidizing Agent

[0022] GDP- Recycled Polyol

[0023] FBK- Fossil-Based Carbon Ratio

[0024] BBK- Bio-Based Carbon Ratio

[0025] Detailed Description of the Invention

[0026] In order to reintegrate the scraps (or wastes) generated during the production of flexible polyurethane foams (PUR) into the system, the recycled polyol production method of the invention comprises the following steps in sequence: - In the first step, the addition of polyol obtained from natural oils as the base polyol, natural oil, and anhydride into reactor

[0027] - In the second step, heating the reactants from the first step by increasing the temperature to a specific value

[0028] - In the third step, dosing the oxidizing agent (or oxidant) into the reactor over a specific period of time, and in the meantime, performing cooling to prevent the temperature from exceeding a certain value due to the exothermic nature of the reaction

[0029] - In the fourth step, continuing the reaction for a specific duration and at specific temperatures after the completion of dosing

[0030] - In the fifth step, heating the existing reactants by increasing the temperature to a specific value after the completion of the oxidation reaction

[0031] - In the sixth step, adding flexible PUR foam wastes to the existing reactants over a specific period of time, and meanwhile, heating the existing reactants in a controlled manner by increasing the temperature from an initial value to predetermined temperature levels

[0032] - In the seventh step, applying vacuum to the reactor at a specified level when the acid number falls below a certain value, and continuing the vacuum process until the water content in the reactor drops below a certain percentage

[0033] - In the eighth step, cooling the reactor to a specific temperature and obtaining the recycled polyol

[0034] In the first step of the method, a polyol obtained from natural oils with an OH value of 60- 75 mgKOH / g and a molecular weight of 2000-3000 g / mol is used. During acidolysis, the polyol derived from natural oils does not participate in the reaction but acts merely as a solvent, thereby reducing viscosity and improving processability. The selection of a polyol with the aforementioned properties is important for increasing the bio-based carbon content.

[0035] In addition, palm oil is used as the natural oil, with an iodine value of 57-65 gI / 100 g of oil. The iodine value specified here is important. Since the iodine value is directly proportional to the number of double bonds and the corresponding number of double bonds for this iodine value is 1.5-2.0 DB / mol of oil. In the first step of the method, 25% to 30% by weight of polyol obtained from natural oils (base polyol), 20% to 25% of natural oil with low double bond content, and 4% to 8% of anhydride are used based on the total amount. In the preferred embodiment of the invention, said natural oil is palm oil with a double bound value of 1.7 DB / mol. By using a polyol obtained from natural oils instead of the polyether polyol used in the invention in the main patent, the amount of petroleum-derived products in the resulting recycled polyol has been reduced, and the amount of bio-based renewable products has been increased. Additionally, the polyether polyol used as the base polyol in the main patent was utilized as a solvent. Similarly, in the present invention, the polyol obtained from natural oils used as the base polyol was also used as a solvent, and no changes were made to the formulation or the method steps in this study.

[0036] In the third step, the oxidizing agent is used at a concentration of 2% to 5% by weight based on the total amount. Oxygen (O2), ozone (O3), hydrogen peroxide (H2O2), inorganic peroxides, or peroxy acids are used as the oxidizing agent. The temperature mentioned in the third step is between 40 °C and 50 °C. The dosing time of the oxidizing agent in the third step is between 1 and 2 hours. The temperature in the third step must not exceed 80 °C.

[0037] The duration mentioned in the fourth step is between 1 and 2 hours, and the temperature is between 70 °C and 80 °C.

[0038] The temperature specified in the fifth step is between 110 °C and 130 °C.

[0039] In the sixth step, the flexible PUR foam wastes mentioned are at a concentration of 38% to 42% by weight based on the total amount. Additionally, the duration for adding the flexible PUR foam wastes to the existing reactants in the sixth step is between 2 and 3 hours. In the same step, said initial temperature is 120 °C, and the temperature of the reactants is increased from this value to between 200 °C and 220 °C.

[0040] In the seventh step, the mentioned acid number is 2 mg KOH / g and the applied vacuum value is -0.8 atm. Additionally, the water content referenced in the seventh step is 1%.

[0041] In the final step, the cooling temperature is between 80 °C and 90 °C.

[0042] The reaction scheme of the method of the invention (Scheme I) is as follows, and among the components added to the reactor, the oxidation reaction of the anhydride and oil occurs first.

[0043] Anhydride Oxidizing Monoperoxy

[0044] Agent Dicarboxylic Acid

[0045] Natural Oil Agent

[0046] Epoxidized

[0047] Oil

[0048] Equivalent weight of PUR

[0049] The molecular weight calculation of the flexible PUR waste used is given below.

[0050] 1170 g / mol + 87 g / mol = 1257 g / mol

[0051] Each 1 mol equivalent of polyurethane is converted into 1 mol of monoperoxy dicarboxylic acid through oxidation. Each 1 mol equivalent of polyurethane waste reacts with 1 mol equivalent of anhydride (monoperoxy dicarboxylic acid).

[0052] Each 1 mol equivalent of disubstituted urea requires 0.6 mol of epoxidized oil to react. However, in the reaction, epoxidized oil is used in 10-25% excess. Scheme II: Flexible polyurethane (PUR) wastes react with monoperoxy dicarboxylic acid to form disubstituted urea, recycled polyol, and CO2.

[0053] Scheme II

[0054] Polyurethane Monoperoxy dicarboxylic acid

[0055] Disubstituted Amino Carboxylic Acid Recycled Polyol Scheme III: The disubstituted urea formed after the initial reaction reacts with epoxidized oil, which is obtained through the oxidation of palm oil, resulting in the production of recycled polyol.

[0056] Scheme III

[0057] Disubstituted Urea Epoxidized Oil Recycled Polyol The recycling or natural degradation of bio-based materials is generally easier compared to petroleum-based products. Therefore, by incorporating polyol obtained from natural oils instead of the petroleum-based polyol, the increase in bio-based content from 40% (as in the main patent) to 62% will allow the polyurethane material produced from the resulting recycled polyol to degrade more easily in nature or to be separated more easily during recycling processes. Initial Formulation:

[0058] Table 1: Recycled polyol recipe

[0059] The polyol was produced from recycled polyurethane scraps via an acidolysis reaction method. The properties of the resulting polyol are presented in Table-2:

[0060] Table 2: Technical Properties of the Polyol

[0061] In summary, instead of the petroleum-derived polyol used as the base polyol in the main patent, the invention utilizes a polyol obtained from natural oils with a high bio-based carbon content (98.5%). No changes were observed in the technical properties of the resulting recycled product, and a bio-based carbon content analysis was conducted. When the petroleum-derived base polyol in the system was replaced with a polyol obtained from natural oils with a 98.5% bio-based carbon content, the bio-based carbon content increased to 62% (Figure-2b and Table-3). In this way, both the environmental damage caused by flexible polyurethane foam wastes is reduced, and the use of petroleum-derived raw materials is decreased, resulting in a polyol with a high bio-based content.

[0062] In the invention, a bio-based carbon content analysis was conducted on the polyol obtained from natural oils in accordance with the standard of ASTM D6866-24 METHOD B by an analytical laboratory in the United States. Bio-based carbon content refers to the proportion of total carbon in polymers or products that originates from biological sources. It is defined as the total carbon component obtained from renewable resources and environmentally friendly materials. This represents the percentage of carbon originating from “natural” (plant- or animal -based byproduct) sources compared to “synthetic” (petrochemical) sources. The analysis revealed that the polyol obtained from natural oils has a bio-based carbon content of 98%. According to the result of the analysis, the natural oil-based polyol (NOP) will contribute to the reduction of petroleum-based polyol usage and enhance environmental sustainability.

[0063] Table 3: Comparison of Bio-based Carbon Content Analysis of the Main Patent and the Invention

[0064] Industrial Applicability of the Invention The invention relates to a sustainable, eco-friendly, and recycled polyol production method using flexible polyurethane foam scraps generated during the production of flexible polyurethane foam, enabling their reintegration into the system. The invention is applicable in industry.

[0065] The invention is not limited to the exemplary embodiments above, a skilled person in the art can perform different embodiments of the invention easily. These should be interpreted within the protection scope of the invention claimed with the claims.

Claims

CLAIMS1. A method for producing recycled polyol, characterized by comprising the following sequential steps for reintroducing scraps (or wastes) generated during the production of flexible polyurethane foams (PUR) into the system:In the first step, the addition of polyol obtained from natural oils as the base polyol, natural oil, and anhydride into reactorIn the second step, heating the reactants from the first step by increasing the temperature to a specific valueIn the third step, dosing the oxidizing agent into the reactor over a specific period of time, and in the meantime, performing cooling to prevent the temperature from exceeding a certain value due to the exothermic nature of the reaction- In the fourth step, continuing the reaction for a specific duration and at specific temperatures after the completion of dosingIn the fifth step, heating the existing reactants by increasing the temperature to a specific value after the completion of the oxidation reactionIn the sixth step, adding flexible PUR foam wastes to the existing reactants over a specific period of time, and meanwhile, heating the existing reactants in a controlled manner by increasing the temperature from an initial value to predetermined temperature levelsIn the seventh step, applying vacuum to the reactor at a specified level when the acid number falls below a certain value, and continuing the vacuum process until the water content in the reactor drops below a certain percentageIn the eighth step, cooling the reactor to a specific temperature and obtaining the recycled polyol.

2. The method according to claim 1 , characterized in that the polyol obtained from natural oils used in the first step is a polyol having an OH value of 60-75 mg KOH / g and a molecular weight of 2000-3000 g / mol.

3. The method according to claim 2, characterized in that the natural oil used in the first step is palm oil having an iodine value of 57-65 g 1 / 100 g and 1.5-2.0 DB / mol.

4. The method according to claim 3, characterized in that the natural oil mentioned in the first step of the method is palm oil having a value of 1.7 DB / mol.

5. The method according to claim 4, characterized in that, in the first step, 25 to 30 wt% of polyol obtained from natural oils (base polyol), 20 to 25 wt% of natural oil with low double bond content, and 4 to 8 wt% of anhydride are used, based on the total amount.

6. A method according to claim 5, characterized in that the oxidation agent used in the third step is used in an amount of 2 to 5 wt% based on the total amount.

7. The method according to claim 6, characterized in that the temperature mentioned in the third step is between 40 °C and 50 °C.

8. The method according to claim 7, characterized in that the temperature mentioned in the third step does not exceed 80 °C.

9. The method according to claim 8, characterized in that the temperature mentioned in the fifth step is between 110 °C and 130 °C.

10. The method according to claim 9, characterized in that the PUR foam wastes mentioned in the sixth step are in the range of 38% to 42% by weight of the total amount, and the addition time to the existing reactants is between 2 and 3 hours.

11. The method according to claim 10, characterized in that the initial temperature mentioned in the sixth step is 120 °C, and the temperature of the reactants is increased from this value to 200 °C to 220 °C.

12. The method according to claim 11, characterized in that the acid number mentioned in the seventh step is 2 mg KOH / g.

13. The method according to claim 12, characterized in that the vacuum value mentioned in the seventh step is -0.8 atm.

14. The method according to claim 13, characterized in that the percentage value of the water mentioned in the seventh step is 1%.

15. The method according to claim 14, characterized in that the cooling temperature in the final step is between 80°C and 90°C.

Images