Method for preparing whole bio-based surfactant by taking rhamnose waste liquid as raw material and application of whole bio-based surfactant

Abstract

The invention discloses a method for preparing a whole bio-based surfactant by taking rhamnose waste liquid as a raw material and application of the whole bio-based surfactant. The method comprises the following steps: adding the rhamnose waste liquid containing 3-hydroxydecanoic acid and a basic catalyst into a reaction kettle, and uniformly stirring; heating to a certain temperature under the protection of inert gas, slowly introducing ethylene oxide to carry out polymerization reaction, and adding acetic acid to neutralize after the reaction is finished, so as to obtain the 3-hydroxydecanoic acid polyoxyethylene ether. The invention aims to prepare the full bio-based surfactant 3-hydroxydecanoic acid polyoxyethylene ether from the rhamnose waste liquid, on one hand, the main component 3-hydroxydecanoic acid in the rhamnose waste liquid can be reused, the added value of the product is increased, the waste liquid discharge is reduced, and the method is more environment-friendly; on the other hand, the method is simple and convenient to operate and low in cost, and the prepared surfactant is more natural, green and safe.

Description

Technical Field

[0001] The invention belongs to the field of biochemistry, and specifically relates to a method for preparing a fully bio-based surfactant using rhamnose waste liquid as a raw material and an application thereof. Background Art

[0002] Rhamnose, also known as 6-deoxy-L-mannose, is a substance widely found in polysaccharides, glycosides, plant gums and bacterial polysaccharides in plants, with a sweetness of about 33% of sucrose. Rhamnose has many uses in industry. It can be used as a sweetener, a component in the production of flavors and fragrances, and can be used to measure intestinal permeability. At present, it is an important and feasible industrial route to prepare rhamnose by hydrolysis reaction under acidic conditions using rhamnose esters as raw materials (such as patents US4933281A and US5550227A), but this route will produce an oil phase waste liquid, the main components of which include a variety of hydroxyalkyl acids, such as 3-hydroxydecanoic acid, 3-hydroxydecanoic acid dimer, 3-hydroxyoctanoic acid, etc. The separation of organic matter in rhamnose waste liquid by distillation is not only energy-intensive, but also difficult, which is not conducive to economical production; and treating it as waste liquid not only requires increasing the cost of waste liquid treatment, but also wastes a lot of resources. Therefore, in the process of preparing rhamnose by hydrolysis of rhamnolipids, it is of great significance to develop the reuse of organic matter in rhamnose wastewater.

[0003] Surfactants are an important chemical product, widely used in detergents, cleaning agents, personal care products, food industry, pharmaceutical industry and other fields. Traditional surfactants are mostly synthesized from petrochemical products, which have problems such as environmental pollution and waste of resources. With the increasing awareness of environmental protection and the demand for sustainable development, bio-based surfactants have become a hot spot for research and development due to their advantages such as being derived from renewable resources, environmentally friendly and having a wide range of applications. Existing bio-based surfactants are mainly prepared by microbial fermentation, enzyme catalysis and natural biological extraction. For example, bio-based surfactants such as fatty acid methyl esters and monoglycerides can be produced by microbial fermentation; bio-based surfactants such as monoglycerides, sugar esters, phospholipids, and alkyl glycosides can be synthesized by enzyme catalysis; bio-based surfactants such as phospholipids and lecithin can be extracted from natural biological raw materials such as egg yolks or soybeans. However, the microbial fermentation method has problems such as complex fermentation process, long cycle and low yield; the enzyme catalysis method has problems such as high enzyme cost and difficulty in obtaining enzymes, and easy enzyme inactivation; the natural biological extraction method has problems such as limited resources, complex extraction process and low content of active ingredients. In general, the bio-based surfactants synthesized by the above methods have the limitations of high production cost, low production efficiency and difficulty in product separation. Therefore, developing a green, environmentally friendly, low-cost and high-efficiency method for preparing bio-based surfactants is an urgent problem to be solved in this field. Summary of the invention

[0004] In order to solve the above technical problems, the present invention proposes a method for synthesizing a fully bio-based surfactant 3-hydroxydecanoic acid polyoxyethylene ether using 3-hydroxydecanoic acid in rhamnose waste liquid as a raw material. On the one hand, the main component 3-hydroxydecanoic acid in the rhamnose waste liquid can be reused to increase the added value of the product, and the waste liquid discharge is reduced, which is more environmentally friendly; on the other hand, the method is simple to operate, low in cost, and the prepared surfactant is more natural, green and safe.

[0005] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is as follows:

[0006] A method for preparing a fully bio-based surfactant using rhamnose waste liquid as a raw material, the method comprising the following steps:

[0007] Rhamnose waste liquid containing 3-hydroxydecanoic acid and an alkaline catalyst are added into a reactor and stirred evenly. After heating to a certain temperature under inert gas protection conditions, ethylene oxide is slowly introduced to carry out polymerization reaction. After the reaction is completed, acetic acid is added for neutralization to obtain 3-hydroxydecanoic acid polyoxyethylene ether.

[0008] As a preferred embodiment, the rhamnose waste liquid comprises: 60-70wt% of 3-hydroxydecanoic acid, 5-10wt% of 3-hydroxydecanoic acid dimer, 5-10wt% of 3-hydroxyoctanoic acid, and 10-20wt% of other components.

[0009] As a preferred embodiment, the rhamnose waste liquid can be first concentrated to obtain a 3-hydroxydecanoic acid solution, and then mixed with an alkaline catalyst. The concentration process can be performed by distillation, as described in patent CN117756754A. Specifically, the distillation temperature is 100-200°C, preferably 120-170°C; the distillation pressure is 0.1-5KPaA, preferably 0.5-3KPaA.

[0010] As a preferred embodiment, the alkaline catalyst is selected from one or more of sodium hydroxide, potassium hydroxide, sodium methoxide, potassium methoxide, preferably potassium hydroxide.

[0011] As a preferred embodiment, the amount of the alkaline catalyst is 0.1% to 1% by mass of the 3-hydroxydecanoic acid, preferably 0.3% to 0.6% by mass.

[0012] As a preferred embodiment, the inert gas is nitrogen.

[0013] As a preferred embodiment, the polymerization reaction temperature is 120-180° C., preferably 140-160° C.; the reaction pressure is 0.05-0.3 MPaG, preferably 0.1-0.2 MPaG.

[0014] As a preferred embodiment, the molar ratio of 3-hydroxydecanoic acid to ethylene oxide is 1:5 to 1:14, preferably 1:8 to 1:12.

[0015] As a preferred embodiment, the addition time of ethylene oxide is 0.5 to 3 hours, preferably 1 to 2 hours.

[0016] As a preferred embodiment, the polymerization reaction time is 1 to 5 hours, preferably 2 to 4 hours, and the polymerization reaction time does not include the aforementioned addition time of ethylene oxide.

[0017] As a preferred embodiment, the pH of the acetic acid after neutralization is 7-8, and the neutralization temperature is 70-80°C.

[0018] Another object of the present invention is to provide a fully bio-based surfactant 3-hydroxydecanoic acid polyoxyethylene ether.

[0019] A fully bio-based surfactant, 3-hydroxydecanoic acid polyoxyethylene ether, is prepared by the method.

[0020] Another object of the present invention is to provide the application of the above-mentioned all-biobased surfactant 3-hydroxydecanoic acid polyoxyethylene ether in the field of daily chemical products, preferably in the fields of detergents, cleaning agents, personal care products, etc.

[0021] The beneficial effects of the technical solution of the present invention are:

[0022] (1) A new surfactant is synthesized by a one-step reaction, and its raw material, rhamnose waste liquid, comes from natural raw materials, so that the prepared surfactant 3-hydroxydecanoic acid polyoxyethylene ether is more natural, green and safe, and the synthesis process is simple to operate and the raw material cost is low;

[0023] (2) The use of rhamnose waste liquid to synthesize the fully bio-based surfactant 3-hydroxydecanoic acid polyoxyethylene ether not only solves the problem of waste liquid treatment, but also realizes waste utilization, improves atomic utilization, and increases product added value. DETAILED DESCRIPTION

[0024] The present invention is further described below by means of specific examples. The examples described in the present invention are only used to illustrate the present invention and do not limit the scope of the present invention.

[0025] The main analytical instruments and surfactant performance testing methods used in the embodiments of the present invention are as follows:

[0026] Liquid chromatograph: Instrument model: Agilent 1200 series; Chromatographic column: C18; Column temperature: 40°C; Mobile phase: acetonitrile and 0.03wt% phosphoric acid aqueous solution, Flow rate: 0.8mL / min; UV detector wavelength: 285nm. Quantification was performed using the external standard method. The sample was appropriately diluted with acetonitrile before injection and then analyzed.

[0027] Gas chromatography: The gas chromatograph was Agilent 1200 series, with an initial temperature of 150°C, maintained for 2 min, then programmed to 280°C at a rate of 15°C / min, and maintained for 5 min; vaporization chamber temperature 280°C, detection chamber temperature 280°C; FID detection; injection volume 0.2 μL.

[0028] Turbidity point test: Turbidity point test is carried out according to the method shown in national standard GB / T 5559-2010.

[0029] Wetting force test: Wetting force test is carried out according to the method shown in the national standard GB / T 11983-2008.

[0030] Surface tension test: Surface tension test was carried out according to the method specified in national standard GB / T 22237-2008.

[0031] Foam performance test: Instrument model: Roche foam tester XH-2152, temperature: 40°C, solution concentration: 0.25%.

[0032] The sources of the main raw materials used in the examples of the present invention are as follows. Other sources are obtained from common commercial channels unless otherwise specified:

[0033] Rhamnolipid aqueous solution, with a content of 40 wt %, was purchased from Evonik Specialty Chemicals (Shanghai) Co., Ltd.

[0034] Sodium hydroxide, potassium hydroxide, sodium methoxide, potassium methoxide, acetic acid, and concentrated sulfuric acid were analytically pure and purchased from Aladdin Reagent Co., Ltd.

[0035] Preparation Example 1: Preparation of rhamnose waste liquid

[0036] 1000g of a 40% rhamnolipid aqueous solution was mixed with 1650g of pure water to prepare a 15% rhamnolipid aqueous solution, and then 80g of concentrated sulfuric acid was added, and the mixture was fully mixed and added to a high-pressure reactor; the high-pressure reactor was filled with nitrogen to 0.5MPaG, and then the temperature was raised to 140°C, and the reaction was carried out for 3 hours and then the heating was stopped; after the temperature dropped to 25°C, the stirring was stopped, the reaction solution was discharged, and the reaction solution was allowed to stand for 30 minutes to separate into oil and water phases, and an oil phase containing 3-hydroxydecanoic acid and an aqueous phase containing rhamnose were obtained, wherein the oil phase was rhamnose waste liquid, and its composition was as follows: 68wt% of 3-hydroxydecanoic acid, 8wt% of 3-hydroxydecanoic acid dimer, 5% of 3-hydroxyoctanoic acid, and 19wt% of other components by liquid chromatography analysis.

[0037] Preparation Example 2: Separation of 3-hydroxydecanoic acid from rhamnose wastewater

[0038] The rhamnose waste liquid in Preparation Example 1 was distilled at 120° C. and 3.0 KPaA to separate and obtain a 3-hydroxydecanoic acid solution with a purity of 93 wt %.

[0039] Example 1

[0040] 202.4 g of the 3-hydroxydecanoic acid solution and 0.38 g of potassium hydroxide in Preparation Example 2 were respectively added to a reactor, and stirred for 10 minutes to mix evenly; nitrogen was introduced into the reactor, and after the air was completely replaced, the temperature in the reactor was heated to 80° C., and the system was treated at a pressure of -0.08 MPa for 30 minutes to remove moisture from the system; then 396.5 g of ethylene oxide was continuously added to the reactor within 1 hour for polymerization reaction, the reaction temperature was controlled to 130° C. and the reaction pressure was controlled to 0.15 MPaG, and the reaction was continued for 2 hours after the addition of ethylene oxide; after the reaction was completed, the temperature was lowered to 70° C., acetic acid was added to neutralize to a pH of 7.0, and a 3-hydroxydecanoic acid polyoxyethylene ether product was obtained. The ethylene oxide conversion rate was 91.1% after testing and analysis, and the performance test results of the 3-hydroxydecanoic acid polyoxyethylene ether product are shown in Table 1.

[0041] Table 1 Performance test of 3-hydroxydecanoic acid polyoxyethylene ether in Example 1

[0042]

[0043] Example 2

[0044] 202.4 g of the 3-hydroxydecanoic acid solution and 0.75 g of potassium hydroxide in Preparation Example 2 were respectively added to a reactor, and stirred for 10 minutes to mix evenly; nitrogen was introduced into the reactor, and after the air was completely replaced, the temperature in the reactor was heated to 80° C., and treated at a pressure of -0.08 MPa for 30 minutes to remove moisture in the system; then 528.6 g of ethylene oxide was continuously added to the reactor within 2 hours for polymerization reaction, the reaction temperature was controlled to 140° C. and the reaction pressure was controlled to 0.15 MPaG, and the reaction was continued for 3 hours after the addition of ethylene oxide; after the reaction was completed, the temperature was lowered to 70° C., acetic acid was added to neutralize to a pH of 7.0, and a 3-hydroxydecanoic acid polyoxyethylene ether product was obtained. The ethylene oxide conversion rate was 95.5% after testing and analysis, and the performance test results of the 3-hydroxydecanoic acid polyoxyethylene ether product are shown in Table 2.

[0045] Table 2 Performance test of 3-hydroxydecanoic acid polyoxyethylene ether in Example 2

[0046]

[0047]

[0048] Example 3

[0049] 202.4 g of the 3-hydroxydecanoic acid solution and 0.56 g of potassium hydroxide in Preparation Example 2 were added to a reactor, stirred for 10 minutes to mix evenly; nitrogen was introduced into the reactor, and after the air was completely replaced, the temperature in the reactor was heated to 80° C., and treated at a pressure of -0.08 MPa for 30 minutes to remove moisture in the system; then 484.6 g of ethylene oxide was continuously added to the reactor within 2 hours for polymerization reaction, the reaction temperature was controlled to 150° C. and the reaction pressure was controlled to 0.2 MPaG, and the reaction was continued for 2 hours after the addition of ethylene oxide; after the reaction was completed, the temperature was lowered to 70° C., acetic acid was added to neutralize to a pH of 7.0, and a 3-hydroxydecanoic acid polyoxyethylene ether product was obtained. The ethylene oxide conversion rate was 98.8% after testing and analysis, and the performance test results of the 3-hydroxydecanoic acid polyoxyethylene ether product are shown in Table 3.

[0050] Table 3 Performance test of 3-hydroxydecanoic acid polyoxyethylene ether in Example 3

[0051]

[0052] Example 4

[0053] 202.4 g of the 3-hydroxydecanoic acid solution and 0.75 g of potassium hydroxide in Preparation Example 2 were added to a reactor, stirred for 10 minutes to mix evenly; nitrogen was introduced into the reactor, and after the air was completely replaced, the temperature in the reactor was heated to 80° C., and treated at a pressure of -0.08 MPa for 30 minutes to remove moisture in the system; then 308.4 g of ethylene oxide was continuously added to the reactor within 3 hours for polymerization reaction, the reaction temperature was controlled to 140° C. and the reaction pressure was controlled to 0.2 MPaG, and the reaction was continued for 2 hours after the addition of ethylene oxide; after the reaction was completed, the temperature was lowered to 70° C., acetic acid was added to neutralize to a pH of 7.0, and a 3-hydroxydecanoic acid polyoxyethylene ether product was obtained. The ethylene oxide conversion rate was 100% after testing and analysis, and the performance test results of the 3-hydroxydecanoic acid polyoxyethylene ether product are shown in Table 4.

[0054] Table 4 Performance test of 3-hydroxydecanoic acid polyoxyethylene ether in Example 4

[0055]

[0056] Example 5

[0057] 202.4 g of the 3-hydroxydecanoic acid solution and 1.1 g of potassium hydroxide in Preparation Example 2 were respectively added to a reactor, stirred for 10 minutes to mix evenly; nitrogen was introduced into the reactor, and after the air was completely replaced, the temperature in the reactor was heated to 80° C., and treated at a pressure of -0.08 MPa for 30 minutes to remove moisture in the system; then 396.5 g of ethylene oxide was continuously added to the reactor within 2 hours for polymerization reaction, the reaction temperature was controlled to 150° C. and the reaction pressure was controlled to 0.1 MPaG, and the reaction was continued for 3 hours after the addition of ethylene oxide; after the reaction was completed, the temperature was lowered to 70° C., acetic acid was added to neutralize to a pH of 7.0, and a 3-hydroxydecanoic acid polyoxyethylene ether product was obtained. The ethylene oxide conversion rate was 100% after testing and analysis, and the performance test results of the 3-hydroxydecanoic acid polyoxyethylene ether product are shown in Table 5.

[0058] Table 5 Performance test of 3-hydroxydecanoic acid polyoxyethylene ether in Example 5

[0059]

[0060] Example 6

[0061] 202.4 g of the 3-hydroxydecanoic acid solution and 0.94 g of potassium hydroxide in Preparation Example 2 were respectively added to a reactor and stirred for 10 minutes to mix evenly; nitrogen was introduced into the reactor, and after the air was completely replaced, the temperature in the reactor was heated to 80° C. and treated at a pressure of -0.08 MPa for 30 minutes to remove moisture from the system; then 440.5 g of ethylene oxide was continuously added to the reactor within 2 hours for polymerization reaction, the reaction temperature was controlled to 145° C. and the reaction pressure was controlled to 0.15 MPaG, and the reaction was continued for 4 hours after the addition of ethylene oxide; after the reaction was completed, the temperature was lowered to 70° C., acetic acid was added to neutralize to a pH of 7.0, and a 3-hydroxydecanoic acid polyoxyethylene ether product was obtained. The ethylene oxide conversion rate was 100% after testing and analysis, and the performance test results of the 3-hydroxydecanoic acid polyoxyethylene ether product are shown in Table 6.

[0062] Table 6 Performance test of 3-hydroxydecanoic acid polyoxyethylene ether in Example 6

[0063]

[0064] Comparative Example 1

[0065] AEO-9, chemically known as fatty alcohol polyoxyethylene ether, is a nonionic surfactant. It is made by the addition of natural fatty alcohol and ethylene oxide. It has good emulsification, dispersion, decontamination, cleaning, wetting and other properties, and is widely used in cosmetics, detergents, industrial cleaning agents and other fields. The performance of AEO-9 product (purchased from Beijing Inokai Technology Co., Ltd.) was tested using the same test method as in the example, and the results are shown in Table 7.

[0066] Table 7 Performance test of AEO-9 in comparative example 1

[0067] Test items AEO-9 Product Test Concentration Test temperature result Cloud point 2.50wt% — 79℃ Wetting power 0.10wt% 25℃ 85s Surface tension 0.10wt% 25℃ 31.21mN / m Foam performance 0.25wt% 40℃ 180mm

[0068] The 3-hydroxydecanoic acid polyoxyethylene ether product prepared in the embodiment is derived from 3-hydroxydecanoic acid in rhamnose waste liquid, which can realize the utilization of waste liquid and increase the added value of the product. At the same time, the prepared 3-hydroxydecanoic acid polyoxyethylene ether product has similar or even better performance than AEO-9. The 3-hydroxydecanoic acid polyoxyethylene ether product prepared by the present invention is more natural, green and safe, and has potential applications in the fields of detergents, cleaning agents and personal care products.

[0069] The above is only a preferred embodiment of the present invention. It should be pointed out that ordinary technicians in this field can make several improvements and supplements without departing from the method of the present invention. These improvements and supplements should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a fully bio-based surfactant using rhamnose waste liquid as raw material, characterized in that: The method comprises the following steps: Rhamnose waste liquid containing 3-hydroxydecanoic acid and an alkaline catalyst are added into a reactor and stirred evenly. After heating to a certain temperature under inert gas protection conditions, ethylene oxide is slowly introduced to carry out polymerization reaction. After the reaction is completed, acetic acid is added for neutralization to obtain 3-hydroxydecanoic acid polyoxyethylene ether.

2. The method according to claim 1, characterized in that The rhamnose waste liquid comprises: 60-70 wt % of 3-hydroxydecanoic acid, 5-10 wt % of 3-hydroxydecanoic acid dimer, 5-10 wt % of 3-hydroxyoctanoic acid, and 10-20 wt % of other components.

3. The method according to claim 1, characterized in that The alkaline catalyst is selected from one or more of sodium hydroxide, potassium hydroxide, sodium methoxide, potassium methoxide, preferably potassium hydroxide; preferably, the amount of the alkaline catalyst is 0.1% to 1% of the mass of 3-hydroxydecanoic acid, more preferably 0.3% to 0.6%.

4. The method according to claim 1, characterized in that: The polymerization reaction temperature is 120-180° C., preferably 140-160° C., and the reaction pressure is 0.05-0.3 MPaG, preferably 0.1-0.2 MPaG.

5. The method according to claim 1, characterized in that The molar ratio of the 3-hydroxydecanoic acid to ethylene oxide is 1:5 to 1:14, preferably 1:8 to 1:

12.

6. The method according to claim 1, characterized in that The addition time of the ethylene oxide is 0.5-3 h, preferably 1-2 h; preferably, the polymerization reaction time is 1-5 h, more preferably 2-4 h.

7. The method according to claim 1, characterized in that The neutralization pH of the acetic acid is 7-8, and the neutralization temperature is 70-80°C.

8. The method according to any one of claims 1 to 7, characterized in that: The rhamnose waste liquid containing 3-hydroxydecanoic acid is concentrated to obtain a 3-hydroxydecanoic acid solution, which is then mixed with an alkaline catalyst and added to a reactor; the preferred concentration treatment is distillation, and more preferably the distillation temperature is 100-200° C. and the distillation pressure is 0.1-5 KPaA.

9. A fully bio-based surfactant 3-hydroxydecanoic acid polyoxyethylene ether, wherein the 3-hydroxydecanoic acid polyoxyethylene ether is prepared by the method described in any one of claims 1 to 8.

10. Use of the all-biobased surfactant 3-hydroxydecanoic acid polyoxyethylene ether according to claim 9 in the fields of detergents, cleaning agents, and personal care products.

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