Synthesis process of cocoyl ethanolamine

Abstract

The invention relates to the technical field of surfactant synthesis, and discloses a synthesis process of coconut oil acyl ethanolamine, a specific catalyst is adopted, the synthesis process comprises the following steps: S1, coconut oil fatty acid and methyl monoethanolamine are added into a reactor according to a certain feeding ratio, and then sodium hydroxide and a catalyst are added into the reactor; s2, under the protection of nitrogen, carrying out a reaction under specific reaction conditions to obtain a reaction mixed solution; s3, adding diethyl ether and deionized water into the reaction mixed solution, standing for layering, taking an oil phase, and distilling to recover diethyl ether, so as to obtain a crude coconut oil acyl ethanolamine product; and S4, carrying out purification treatment on the crude coconut oil acyl ethanolamine product prepared in the step S3, so as to prepare a pure coconut oil acyl ethanolamine product. The specific composite catalyst is adopted, the reaction conversion rate is high, the purity of the prepared product is high, the catalyst can be recycled, and the synthesis cost is low.

Description

Technical Field

[0001] The present application relates to the technical field of surfactant synthesis, and in particular to a synthesis process of cocoylethanolamine. Background Art

[0002] Cocoylethanolamine, also known as cocoyl monoethanolamine, is a new nonionic surfactant. Its performance is similar to that of cocoyl diethanolamine, but it eliminates the safety concerns of cocoyl diethanolamine, which contains free diethanolamine and is easily nitrosylated to form highly carcinogenic nitrosamines. Furthermore, cocoylethanolamine exhibits excellent thickening, foaming, and foam stability, as well as rust prevention and antistatic properties. It also possesses excellent calcium soap dispersibility and detergency, and has low toxicity and high biodegradability. Its unique thickening and softening properties make it widely used in the formulation of various detergents and cosmetics.

[0003] Currently, there are three main synthesis processes for cocoylethanolamine: the first is a direct reaction between coconut oil and monoethanolamine. This process does not complete the reaction easily, and the product will contain glycerol and a large amount of free monoethanolamine. The second is a synthesis process between coconut oil fatty acids and monoethanolamine. This process has a high reaction temperature, the product color tends to darken, and there will be by-products such as amine esters. The third is a reaction between coconut oil methyl esterification and monoethanolamine. Although this process has a high reaction conversion rate, it requires the use of a specific catalyst, has high synthesis costs, and has risks such as methanol processing.

[0004] Therefore, there is an urgent need to design a process for synthesizing cocoylethanolamine with relatively low cost, high reaction conversion rate and good process safety. Summary of the Invention

[0005] In order to solve at least one of the above technical problems, a synthesis process with high reaction conversion rate, relatively low process cost and high purity of the obtained product is developed. The present application provides a synthesis process of cocoyl ethanolamine.

[0006] The present application provides a synthesis process of cocoylethanolamine, comprising the following steps:

[0007] S1, adding coconut oil fatty acid and methyl monoethanolamine into a reactor in a molar ratio of 1:1.1 to 1.5, and then adding sodium hydroxide and a catalyst into the reactor to complete the reaction solution configuration;

[0008] S2. Stir the reaction solution prepared in step S1 at 90-120° C. under nitrogen protection for 3.5-5.5 hours to obtain a reaction mixture;

[0009] S3, add ether and deionized water to the reaction mixture obtained in step S2, after standing and stratifying, take the oil phase, and distill and recover ether to obtain a crude product of cocoylethanolamine;

[0010] S4, purifying the crude cocoylethanolamine obtained in step S3 to obtain pure cocoylethanolamine;

[0011] The catalyst comprises porous silica gel particles loaded with vanadium pentoxide and ZSM-5 molecular sieve loaded with aluminum oxide.

[0012] Optionally, in step S1, coconut oil fatty acid and methyl monoethanolamine are added in a molar ratio of 1:1.15 to 1.20.

[0013] Optionally, in step S1, sodium hydroxide is added according to a molar ratio of sodium hydroxide to coconut oil fatty acid of 0.4 to 0.6:1.

[0014] Optionally, in step S1, the catalyst is added so that the supported compound accounts for 1 to 2% of the total mass of the coconut oil fatty acid and monoethanolamine.

[0015] Optionally, in step S2, the reaction temperature is 95-100°C.

[0016] Optionally, in step S2, the reaction vacuum degree is 80-85 kPa.

[0017] Optionally, in step S2, the stirring speed is 400-600 rpm.

[0018] Optionally, in step S4, the purification process includes the following steps:

[0019] S4-1. Acetic acid is measured according to a molar ratio of excess monoethanolamine to acetic acid of 1:1.05-1.1 to prepare an acetic acid solution with a concentration of 30-35%;

[0020] S4-2, mixing the acetic acid solution prepared in step S4-1 with the crude cocoylethanolamine, stirring for more than 30 minutes, allowing to stand for stratification, and taking the oil phase;

[0021] S4-3. The oil phase obtained in step S4-2 is subjected to distillation to remove light components to obtain pure cocoyl ethanolamine.

[0022] Optionally, the catalyst further includes an activated carbon catalyst loaded with a ruthenium compound.

[0023] Further optionally, the catalyst is configured according to a molar ratio of vanadium element, aluminum element and ruthenium element of 4:1-2:1-2.

[0024] In summary, the present invention includes at least one of the following beneficial technical effects:

[0025] 1. The present application designs a synthesis process for cocoylethanolamine, which uses a specific catalyst to effectively reduce the reaction temperature, improve reaction safety, and effectively increase the reaction conversion rate; in addition, the catalyst of the present application can be recycled and reused, which can effectively reduce the synthesis cost.

[0026] 2. The synthesis process of cocoylethanolamine designed in this application adopts specific process steps and process conditions, and the cocoylethanolamine obtained has high purity, extremely low free ethanolamine content, and relatively good color and quality. DETAILED DESCRIPTION

[0027] The present application is further described in detail below with reference to the embodiments.

[0028] The present application designs a synthesis process of cocoyl ethanolamine, comprising the following steps:

[0029] S1, adding coconut oil fatty acid and methyl monoethanolamine into a reactor in a molar ratio of 1:1.1 to 1.5, and then adding sodium hydroxide and a catalyst into the reactor to complete the reaction solution configuration;

[0030] S2. Stir the reaction solution prepared in step S1 at 90-120° C. under nitrogen protection for 3.5-5.5 hours to obtain a reaction mixture;

[0031] S3, add ether and deionized water to the reaction mixture obtained in step S2, after standing and stratifying, take the oil phase, and distill and recover ether to obtain a crude product of cocoylethanolamine;

[0032] S4, purifying the crude cocoylethanolamine obtained in step S3 to obtain pure cocoylethanolamine;

[0033] The catalyst comprises porous silica gel particles loaded with vanadium pentoxide and alumina-modified ZSM-5 molecular sieve.

[0034] In the prior art, the synthesis technique of coconut oil fatty acid and monoethanolamine is adopted to synthesize cocoylethanolamine, and reaction temperature is usually higher, and there is the problem that the color and luster of the cocoylethanolamine obtained darkens, and purity is relatively low. In the prior art, it is usually necessary to adopt complicated purification and treatment process, to solve the above problems. Cause the cost of synthesis to be higher, synthesis efficiency is relatively low, and synthesis yield is insufficient.

[0035] The present application effectively reduces the reaction conditions, improves the reaction conversion rate, and effectively reduces the incidence of side reactions by designing a specific composite catalyst, thereby solving many problems existing in the prior art.

[0036] The following are examples of the present application.

[0037] The main raw materials used in the examples of this application are commercially available.

[0038] Among them, porous silica gel particles loaded with vanadium pentoxide were purchased from Shaanxi Kaida Chemical Co., Ltd.; ZSM-5 molecular sieve loaded with alumina was purchased from Beijing Bailingwei Technology Co., Ltd.; activated carbon catalyst loaded with ruthenium compound was purchased from Shaanxi Kaida Chemical Co., Ltd.; coconut oil fatty acid was purchased from Guangzhou Gongxin Chemical Co., Ltd. with a purity of more than 99%; monoethanolamine was purchased from Shandong Kejian Chemical Co., Ltd. with a purity of more than 99%.

[0039] Example 1

[0040] The synthesis process of the cocoylethanolamine of the present embodiment comprises the following steps:

[0041] S1, coconut oil fatty acid and methyl monoethanolamine are added to a reactor according to a molar ratio of 1:1.1, and then sodium hydroxide and a catalyst are added to the reactor to complete the reaction solution configuration; sodium hydroxide is added according to a molar ratio of sodium hydroxide to coconut oil fatty acid of 0.4:1; the catalyst adopts a composite catalyst of porous silica gel particles loaded with vanadium pentoxide and ZSM-5 molecular sieve loaded with aluminum oxide, and is configured according to a molar ratio of vanadium and aluminum elements of 4:1. The amount of catalyst added is based on the total mass of vanadium pentoxide and aluminum oxide in the composite catalyst, accounting for 1% of the total mass of coconut oil fatty acid and monoethanolamine.

[0042] S2. The reaction solution prepared in step S1 was stirred at 90° C. under nitrogen protection for 5.5 h to obtain a reaction mixture; magnetic stirring was used and the stirring speed was controlled at 300 rpm;

[0043] S3, add ether and deionized water to the reaction mixture obtained in step S2, after standing and stratifying, take the oil phase, and distill and recover ether to obtain a crude product of cocoylethanolamine;

[0044] S4, the crude cocoyl ethanolamine obtained in step S3 is subjected to a purification process by distilling and removing light components to obtain pure cocoyl ethanolamine.

[0045] Example 2

[0046] The synthesis process of the cocoylethanolamine of the present embodiment comprises the following steps:

[0047] S1, coconut oil fatty acid and methyl monoethanolamine are added to a reactor according to a molar ratio of 1:1.5, and then sodium hydroxide and a catalyst are added to the reactor to complete the reaction solution configuration; sodium hydroxide is added according to a molar ratio of sodium hydroxide to coconut oil fatty acid of 0.6:1; the catalyst adopts a composite catalyst of porous silica gel particles loaded with vanadium pentoxide and ZSM-5 molecular sieve loaded with aluminum oxide, and is configured according to a molar ratio of vanadium and aluminum elements of 4:1. The amount of catalyst added is based on the total mass of vanadium pentoxide and aluminum oxide in the composite catalyst, accounting for 1% of the total mass of coconut oil fatty acid and monoethanolamine.

[0048] S2. Stirring the reaction solution prepared in step S1 at 120° C. under nitrogen protection for 3.5 hours to obtain a reaction mixture; using magnetic stirring and controlling the stirring speed at 300 rpm;

[0049] S3, add ether and deionized water to the reaction mixture obtained in step S2, after standing and stratifying, take the oil phase, and distill and recover ether to obtain a crude product of cocoylethanolamine;

[0050] S4, the crude cocoyl ethanolamine obtained in step S3 is subjected to a purification process by distilling and removing light components to obtain pure cocoyl ethanolamine.

[0051] Example 3

[0052] The synthesis process of the cocoylethanolamine of the present embodiment comprises the following steps:

[0053] S1, coconut oil fatty acid and methyl monoethanolamine are added to a reactor in a molar ratio of 1:1.15, and then sodium hydroxide and a catalyst are added to the reactor to complete the reaction solution configuration; sodium hydroxide is added according to a molar ratio of sodium hydroxide to coconut oil fatty acid of 0.5:1; the catalyst adopts a composite catalyst of porous silica gel particles loaded with vanadium pentoxide and ZSM-5 molecular sieve loaded with aluminum oxide, and is configured according to a molar ratio of vanadium and aluminum elements of 4:2. The amount of catalyst added is based on the total mass of vanadium pentoxide and aluminum oxide in the composite catalyst, accounting for 2% of the total mass of coconut oil fatty acid and monoethanolamine.

[0054] S2. The reaction solution prepared in step S1 was stirred at 95° C. under nitrogen protection for 4.5 hours to obtain a reaction mixture; magnetic stirring was used and the stirring speed was controlled at 400 rpm;

[0055] S3, add ether and deionized water to the reaction mixture obtained in step S2, after standing and stratifying, take the oil phase, and distill and recover ether to obtain a crude product of cocoylethanolamine;

[0056] S4, the crude cocoyl ethanolamine obtained in step S3 is subjected to a purification process by distilling and removing light components to obtain pure cocoyl ethanolamine.

[0057] Example 4

[0058] The synthesis process of the cocoylethanolamine of the present embodiment comprises the following steps:

[0059] S1, coconut oil fatty acid and methyl monoethanolamine are added to a reactor according to a molar ratio of 1:1.20, and then sodium hydroxide and a catalyst are added to the reactor to complete the reaction solution configuration; sodium hydroxide is added according to a molar ratio of sodium hydroxide to coconut oil fatty acid of 0.5:1; the catalyst adopts a composite catalyst of porous silica gel particles loaded with vanadium pentoxide and ZSM-5 molecular sieve loaded with aluminum oxide, and is configured according to a molar ratio of vanadium and aluminum elements of 4:2. The amount of catalyst added is based on the total mass of vanadium pentoxide and aluminum oxide in the composite catalyst, accounting for 2% of the total mass of coconut oil fatty acid and monoethanolamine.

[0060] S2. Stir the reaction solution prepared in step S1 at 100° C. under nitrogen protection for 4.0 h to obtain a reaction mixture; use magnetic stirring and control the stirring speed at 600 rpm;

[0061] S3, add ether and deionized water to the reaction mixture obtained in step S2, after standing and stratifying, take the oil phase, and distill and recover ether to obtain a crude product of cocoylethanolamine;

[0062] S4, the crude cocoyl ethanolamine obtained in step S3 is subjected to a purification process by distilling and removing light components to obtain pure cocoyl ethanolamine.

[0063] Example 5

[0064] The difference between this embodiment and the fourth embodiment is that in step S2, the reaction vacuum degree is controlled at 80-85 kPa.

[0065] Example 6

[0066] The difference between this embodiment and the fifth embodiment is that in step S2, magnetic stirring is adopted and the stirring speed is controlled at 550 rpm.

[0067] Example 7

[0068] The difference between this embodiment and embodiment 6 is that in step S4, the purification process adopts the following steps:

[0069] S4-1. Acetic acid was measured at a molar ratio of excess monoethanolamine to acetic acid of 1:1.05 to prepare a 35% acetic acid solution;

[0070] S4-2, mixing the acetic acid solution prepared in step S4-1 with the crude cocoylethanolamine, stirring for 30 minutes, allowing to stand for stratification, and taking the oil phase;

[0071] S4-3. The oil phase obtained in step S4-2 is subjected to distillation to remove light components to obtain pure cocoyl ethanolamine.

[0072] Example 8

[0073] The difference between this embodiment and embodiment 6 is that in step S4, the purification process adopts the following steps:

[0074] S4-1. Acetic acid was measured at a molar ratio of excess monoethanolamine to acetic acid of 1:1.1 to prepare a 30% acetic acid solution;

[0075] S4-2, mixing the acetic acid solution prepared in step S4-1 with the crude cocoylethanolamine, stirring for 30 minutes, allowing to stand for stratification, and taking the oil phase;

[0076] S4-3. The oil phase obtained in step S4-2 is subjected to distillation to remove light components to obtain pure cocoyl ethanolamine.

[0077] Embodiment 9

[0078] The difference between this embodiment and embodiment 8 is that in step S1, the catalyst is a composite catalyst composed of porous silica gel particles loaded with vanadium pentoxide, ZSM-5 molecular sieve loaded with alumina, and activated carbon catalyst loaded with a ruthenium compound, and the catalyst is configured according to a molar ratio of vanadium, aluminum, and ruthenium of 4:2:1. The amount of the catalyst added is 2% of the total mass of the coconut oil fatty acid and monoethanolamine based on the total mass of the vanadium pentoxide, alumina, and ruthenium compound in the composite catalyst.

[0079] Example 10

[0080] The difference between this embodiment and embodiment 8 is that in step S1, the catalyst is a composite catalyst composed of porous silica gel particles loaded with vanadium pentoxide, ZSM-5 molecular sieve loaded with alumina, and activated carbon catalyst loaded with a ruthenium compound, and the catalyst is configured according to a molar ratio of vanadium, aluminum, and ruthenium of 4:2:2. The amount of the catalyst added is 2% of the total mass of the coconut oil fatty acid and monoethanolamine based on the total mass of the vanadium pentoxide, alumina, and ruthenium compound in the composite catalyst.

[0081] Comparative Example 1

[0082] The difference between Comparative Example 1 of the present application and Example 2 is that sodium hydroxide is added according to a molar ratio of sodium hydroxide to coconut oil fatty acid of 0.8:1, and the catalyst of the present application is not added.

[0083] Comparative Example 2

[0084] The synthesis process of the cocoylethanolamine of this comparative example comprises the following steps:

[0085] S1. Coconut oil fatty acids and methyl monoethanolamine are added to a reactor at a molar ratio of 1:1.35, and then sodium hydroxide and vanadium pentoxide catalyst are added to the reactor to complete the reaction solution configuration; sodium hydroxide is added at a molar ratio of sodium hydroxide to coconut oil fatty acids of 0.8:1; and vanadium pentoxide is added at 2% of the total mass of coconut oil fatty acids and monoethanolamine.

[0086] S2. Stir the reaction solution prepared in step S1 at 150° C. under nitrogen protection for 5 h to obtain a reaction mixture;

[0087] S3, add ether and deionized water to the reaction mixture obtained in step S2, after standing and stratifying, take the oil phase, and distill and recover ether to obtain a crude product of cocoylethanolamine;

[0088] S4, purifying the crude cocoylethanolamine obtained in step S3 according to a molecular distillation purification process to obtain pure cocoylethanolamine.

[0089] Detection:

[0090] The purity and color of the cocoylethanolamine products obtained in Examples 1 to 10 and Comparative Examples 1 to 2 of the present application were tested, and the yields were calculated based on coconut oil fatty acids. The test results are shown in Table 1 below.

[0091] Table 1 Test results of Examples 1 to 10 and Comparative Examples 1 to 2

[0092] purity(%) Yield (%) Color Example 1 93.92 93.81 normal Example 2 92.64 94.02 normal Example 3 94.18 94.36 normal Example 4 94.24 94.39 normal Example 5 94.79 95.76 normal Example 6 94.76 95.78 normal Example 7 98.79 95.66 normal Example 8 98.81 95.64 normal Embodiment 9 99.18 96.41 normal Example 10 99.12 96.38 normal Comparative Example 1 82.28 80.64 Darker Comparative Example 2 86.33 83.19 slightly deeper

[0093] It can be seen from the data in Table 1 that the cocoylethanolamine prepared in Examples 1 to 6 of the present application, after purification treatment using only simple distillation, has significantly better purity and yield than the products prepared in Comparative Examples 1 to 2, and the color and quality are relatively better; and in Examples 7 to 8 of the present application, after the purification steps of acid washing and distillation are used, the purity of the product is greatly improved, and the yield is slightly decreased; in Examples 9 to 10 of the present application, after using the optimized composite catalyst, the product purity and yield are further improved.

[0094] It can be seen that the application adopts specific composite catalyst, can effectively improve reaction conversion rate, significantly reduce the generation of side reaction, and obtained cocoyl ethanolamine has relatively excellent purity, and productive rate is also relatively high.And the composite catalyst of the application, using specific solid-state supported catalyst, can be recovered by filtering, vacuum heating purification, removes the organic impurities adsorbed and can be used again, can effectively reduce synthesis cost.

[0095] In addition, through the data comparison of Examples 1 to 10 of the present application, it can be seen that the present application can further improve the reaction conversion rate after optimizing the process parameters, especially adopting a specific reaction vacuum degree.

[0096] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A synthesis process for cocoyl ethanolamine, characterized in that, The following steps are involved: S1, adding coconut oil fatty acid and methyl monoethanolamine into a reactor in a molar ratio of 1:1.1 to 1.5, and then adding sodium hydroxide and a catalyst into the reactor to complete the reaction solution configuration; S2. Stir the reaction solution prepared in step S1 at 90-120° C. under nitrogen protection for 3.5-5.5 hours to obtain a reaction mixture; S3, add ether and deionized water to the reaction mixture obtained in step S2, after standing and stratifying, take the oil phase, and distill and recover ether to obtain a crude product of cocoylethanolamine; S4, purifying the crude cocoylethanolamine obtained in step S3 to obtain pure cocoylethanolamine; The catalyst comprises porous silica gel particles loaded with vanadium pentoxide and ZSM-5 molecular sieve loaded with aluminum oxide.

2. the synthesis technique of cocoyl ethanolamine according to claim 1, is characterized in that, In the step S1, coconut oil fatty acid and methyl monoethanolamine are added in a molar ratio of 1:1.15 to 1.

20.

3. the synthesis technique of cocoyl ethanolamine according to claim 1, is characterized in that, In step S1, sodium hydroxide is added according to a molar ratio of sodium hydroxide to coconut oil fatty acid of 0.4 to 0.6:

1.

4. the synthesis technique of cocoyl ethanolamine according to claim 1, is characterized in that, In the step S1, the catalyst is added so that the supported compound accounts for 1 to 2% of the total mass of the coconut oil fatty acid and monoethanolamine.

5. the synthesis technique of cocoyl ethanolamine according to claim 1, is characterized in that, In step S2, the reaction temperature is 95-100°C.

6. The synthesis technique of cocoylethanolamine according to claim 1, wherein In step S2, the reaction vacuum degree is 80-85 kPa.

7. The synthesis technique of cocoylethanolamine according to claim 1, wherein In step S2, the stirring speed is 400-600 rpm.

8. The synthesis technique of cocoyl ethanolamine according to claim 1, wherein In step S4, the purification process includes the following steps: S4-1. Acetic acid is measured according to a molar ratio of excess monoethanolamine to acetic acid of 1:1.05-1.1 to prepare an acetic acid solution with a concentration of 30-35%; S4-2, mixing the acetic acid solution prepared in step S4-1 with the crude cocoylethanolamine, stirring for more than 30 minutes, allowing to stand for stratification, and taking the oil phase; S4-3. The oil phase obtained in step S4-2 is subjected to distillation to remove light components to obtain pure cocoyl ethanolamine.

9. The synthesis technique of cocoylethanolamine according to claim 1, wherein The catalyst also includes an activated carbon catalyst loaded with a ruthenium compound.

10. The synthesis technique of cocoylethanolamine according to claim 9, wherein The catalyst is configured according to a molar ratio of vanadium element, aluminum element and ruthenium element of 4:1-2:1-2.