Catalyst for synthesis of narrow-distribution nonionic surfactant and preparation method thereof

Abstract

The invention discloses a catalyst for synthesis of a narrow-distribution nonionic surfactant and a preparation method of the catalyst. The catalyst disclosed by the invention is obtained by preparing a solid containing magnesium, aluminum, cobalt and calcium elements by adopting a coprecipitation method and then calcining the solid and a KOH solid. The nonionic surfactant prepared by using the catalyst provided by the invention has the advantages of narrow relative molecular weight distribution, low freezing point and the like.

Description

Technical Field

[0001] The invention belongs to the field of catalyst preparation and relates to a catalyst for synthesizing a narrow distribution nonionic surfactant and a preparation method thereof. Background Art

[0002] As an important fine chemical, non-ionic surfactants are widely used in various industries and are known as industrial monosodium glutamate. Non-ionic surfactants are mainly prepared by ring-opening reaction of raw alcohols such as fatty alcohols and isomeric alcohols with epoxides. At present, the most commonly used catalyst in the industry is KOH. KOH-catalyzed synthesis of non-ionic surfactants has the characteristics of wide application range, high reaction tolerance, and environmental friendliness, but there is also the problem of wide molecular weight distribution of the product.

[0003] Most of the surfactants currently on the market often have the problem of solidification in winter due to their wide molecular weight distribution. When downstream customers use them, they need to use warm water or steam to melt them. This not only wastes energy, but also is not conducive to the rapid use of downstream customers. By using a new catalyst to prepare a narrow distribution non-ionic surfactant, the freezing point of the product can be lowered, which greatly facilitates customers' use in winter. Summary of the invention

[0004] The object of the present invention is to provide a catalyst for the synthesis of narrow distribution nonionic surfactants.

[0005] To achieve the above purpose, the technical solution of the present invention is as follows:

[0006] In a first aspect, the present invention provides a catalyst for the synthesis of narrow distribution nonionic surfactants, comprising oxides of magnesium, aluminum, cobalt, calcium and potassium, or consisting of these oxides; and based on the total molar amount of magnesium, aluminum, cobalt, calcium and potassium elements as 100%, magnesium element accounts for 11.2%-13.2%, aluminum element accounts for 2.8%-6.6%, cobalt element accounts for 5.6%-13.2%, and calcium element accounts for 0.33%-0.98%.

[0007] In a second aspect, the present invention provides a method for preparing the above catalyst, which adopts a co-precipitation method to prepare a solid containing magnesium, aluminum, cobalt and calcium elements, and then calcines the solid with KOH solid to obtain the catalyst.

[0008] In some embodiments, in the above method, the molar ratio of the magnesium element to the aluminum element is 2:1 to 4:1, such as 2:1, 3:1, 4:1, or any ratio and range between these ratios;

[0009] The molar amount of the cobalt element is 1.8-2.2 times that of the aluminum element, for example, 1.8, 1.9, 2.0, 2.1, 2.2 times, or any value and range therebetween;

[0010] The molar amount of the calcium element is 5%-15% of the aluminum element, such as 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, or any value and range therebetween; and / or

[0011] The mass ratio of the KOH solid to the solid containing magnesium, aluminum, cobalt and calcium elements is 2:1 to 4:1, for example, 2:1, 3:1, 4:1, or any ratio and range between these ratios.

[0012] In some embodiments, any of the above methods comprises the following steps:

[0013] a) dissolving magnesium salt, aluminum salt and cobalt salt in water to prepare liquid A;

[0014] b) dissolving one or more of an alkali metal hydroxide, an alkali metal carbonate and an alkali metal bicarbonate in water to form a buffer solution, and adding a calcium salt under stirring to form a B solution, wherein the B solution is stirred without precipitation;

[0015] c) adding the A solution and the B solution to water simultaneously to perform a coprecipitation reaction to obtain a C slurry, and drying the C slurry to obtain a D solid;

[0016] d) grinding KOH solid and the D solid together and then calcining to obtain the catalyst.

[0017] In some embodiments, in the above method, in step a), the magnesium salt is selected from one or more of magnesium chloride, magnesium nitrate, magnesium sulfate or their hydrates, preferably magnesium nitrate or its hydrate; the aluminum salt is selected from one or more of aluminum chloride, aluminum nitrate, aluminum sulfate or their hydrates, preferably aluminum nitrate or its hydrate; the cobalt salt is selected from one or more of cobalt chloride, cobalt nitrate, cobalt sulfate or their hydrates, preferably cobalt nitrate or its hydrate.

[0018] In some embodiments, in any of the above methods, in step b), the alkali metal hydroxide is selected from one or more of sodium hydroxide and potassium hydroxide, preferably potassium hydroxide; the alkali metal carbonate and the alkali metal bicarbonate are selected from one or more of sodium carbonate, sodium bicarbonate, potassium carbonate, and potassium bicarbonate, preferably potassium bicarbonate; the calcium salt is selected from one or more of calcium carbonate, calcium nitrate, and calcium chloride.

[0019] In some embodiments, in any of the above methods, in step c), the coprecipitation reaction temperature is 60-100°C, such as 60°C, 70°C, 80°C, 90°C, 100°C, or any value and range between these values, and the reaction time is 1-6h, such as 1, 2, 3, 4, 5, 6h, or any value and range between these values;

[0020] The drying temperature can be 100°C.

[0021] In some embodiments, in any of the methods described above, in step d), the calcination temperature is 600-900°C, for example, 600°C, 700°C, 800°C, 900°C, or any value and range between these values, and the calcination time is 6-10h, for example, 6, 7, 8, 9, 10h, or any value and range between these values.

[0022] In a third aspect, the present invention provides use of the above catalyst or a catalyst prepared by any of the above methods in catalytic synthesis of nonionic surfactants.

[0023] In some embodiments, in the above use, the nonionic surfactant is prepared by catalyzing the ring-opening polymerization of an epoxy compound using the catalyst;

[0024] The epoxy compound is preferably one or more of ethylene oxide, propylene oxide, and butylene oxide;

[0025] The ring-opening polymerization reaction of the epoxy compound is preferably a ring-opening polymerization reaction of the epoxy compound and an alcohol, and the starting alcohol can be one or more of fatty alcohols (such as C10-18 fatty alcohols), isomeric alcohols (C8-C16 isomeric alcohols), and one or more of synthetic fatty alcohol polyoxyethylene ethers (such as C10-18 fatty alcohol polyoxyethylene ethers), isomeric alcohol polyoxyethylene ethers (C8-C16 isomeric alcohol polyoxyethylene ethers).

[0026] The beneficial effects of the present invention are:

[0027] 1. The nonionic surfactant prepared using the catalyst of the present invention has the advantages of narrow relative molecular weight distribution, low freezing point, etc.

[0028] 2. The catalyst of the present invention can directly replace KOH for the synthesis of non-ionic surfactants, does not require device modification, and is easy to use. DETAILED DESCRIPTION

[0029] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0030] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0031] The present invention will be further described below in conjunction with specific examples. It should be understood that the following examples are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0032] The hydroxyl value is determined in accordance with GB / T 12008.3-2009 "Plastic polyether polyols Part 3: Determination of hydroxyl value".

[0033] PDI was measured using a WATERS GPC 1515 gel chromatography instrument.

[0034] The freezing point was measured using a Delite fully automatic freezing point tester.

[0035] The composition of the catalyst was determined using inductively coupled plasma mass spectrometry (ICP / MS).

[0036] Example 1

[0037] a) Add 2 mol magnesium nitrate, 1 mol aluminum chloride, and 2 mol cobalt chloride into 1000 mL deionized water to prepare solution A.

[0038] b) Add 0.6 mol NaOH and 0.3 mol sodium carbonate to 1000 mL deionized water, and add 0.15 mol calcium carbonate under stirring to prepare solution B.

[0039] c) Liquid A and Liquid B were simultaneously added dropwise into 1000 mL of deionized water, and a coprecipitation reaction was carried out at 60° C. for 1 h to obtain slurry C, and the slurry C was dried at 100° C. to obtain solid D.

[0040] d) KOH solid and D solid were ground together in a mass ratio of 2:1, and then calcined at 600° C. for 8 h to obtain Catalyst I.

[0041] Example 2

[0042] a) Add 3 mol of magnesium sulfate, 1 mol of aluminum nitrate, and 2 mol of cobalt nitrate into 1000 mL of deionized water to prepare solution A.

[0043] b) Add 0.6 mol KOH and 0.6 mol sodium bicarbonate to 1000 mL of deionized water, and add 0.08 mol calcium chloride under stirring to prepare solution B.

[0044] c) Liquid A and Liquid B were simultaneously added dropwise into 1000 mL of deionized water, and a coprecipitation reaction was carried out at 70° C. for 3 h to obtain slurry C, and the slurry C was dried at 100° C. to obtain solid D.

[0045] d) KOH solid and D solid were ground together in a mass ratio of 3:1, and then calcined at 700° C. for 6 h to obtain catalyst II.

[0046] Example 3

[0047] a) Add 4 mol magnesium chloride, 1 mol aluminum chloride and 2 mol cobalt sulfate into 1000 mL deionized water to prepare solution A.

[0048] b) Add 0.6 mol KOH and 0.3 mol potassium carbonate to 1000 mL deionized water, and add 0.12 mol calcium nitrate under stirring to prepare solution B.

[0049] c) Liquid A and Liquid B were simultaneously added dropwise into 1000 mL of deionized water, and a coprecipitation reaction was carried out at 80° C. for 3 h to obtain slurry C, and the slurry C was dried at 100° C. to obtain solid D.

[0050] d) KOH solid and D solid were ground together in a mass ratio of 4:1, and then calcined at 800° C. for 10 h to obtain catalyst III.

[0051] Example 4

[0052] a) Add 3 mol magnesium nitrate, 1 mol aluminum nitrate and 2 mol cobalt nitrate into 1000 mL deionized water to prepare solution A.

[0053] b) Add 0.6 mol KOH and 0.6 mol potassium bicarbonate to 1000 mL of deionized water, and add 0.15 mol calcium nitrate under stirring to prepare solution B.

[0054] c) Liquid A and Liquid B were simultaneously added dropwise into 1000 mL of deionized water, and a coprecipitation reaction was carried out at 100° C. for 6 h to obtain slurry C, and the slurry C was dried at 100° C. to obtain solid D.

[0055] d) KOH solid and D solid were ground together in a mass ratio of 3:1, and then calcined at 900° C. for 9 h to obtain catalyst IV.

[0056] Performance Testing

[0057] A nonionic surfactant is prepared using a catalyst. The synthesis process of the nonionic surfactant is basically the same as the traditional KOH process (comparative example). The specific process is as follows: a measured initiator (C12-14 fatty alcohol, isomeric decanol or isomeric tridecanol) and a catalyst are added to a reactor, and the temperature is increased for dehydration after nitrogen replacement, and the moisture content is less than 500ppm. After the temperature is increased to 110-170°C, epoxide (ethylene oxide) is introduced into the reactor for reaction using a flow meter, and the product is neutralized and degassed after aging, and the temperature is reduced to obtain the product.

[0058] The catalysts used in Examples 5-8 in Table 1 are Catalyst I, Catalyst II, Catalyst III and Catalyst IV prepared in Examples 1-4, respectively. The catalysts used in Comparative Examples 1-4 are all KOH catalysts (B&K Technologies, CAS No.: 1310-58-3).

[0059] The synthesized nonionic surfactants and their performance parameters are shown in Table 1.

[0060] Table 1

[0061]

[0062] By comparing Example 5 and Comparative Example 1, Example 6 and Comparative Example 2, Example 7 and Comparative Example 3, and Example 8 and Comparative Example 4, it can be seen that compared with the non-ionic surfactant prepared using the traditional KOH catalyst, the product prepared using the catalyst of the present invention has the advantages of narrow relative molecular weight distribution and low freezing point.

[0063] Taking the total molar number of Mg, Al, Co, Ca and K elements in the catalyst as 100%, the molar percentage of each element detected is shown in Table 2.

[0064] Table 2

[0065]

[0066]

Claims

1. A catalyst for the synthesis of a narrow distribution nonionic surfactant, comprising oxides of magnesium, aluminum, cobalt, calcium and potassium; and based on the total molar amount of magnesium, aluminum, cobalt, calcium and potassium as 100%, magnesium accounts for 11.2%-13.2%, aluminum accounts for 2.8%-6.6%, cobalt accounts for 5.6%-13.2%, and calcium accounts for 0.33%-0.98%.

2. A method for preparing the catalyst according to claim 1, characterized in that: A solid containing magnesium, aluminum, cobalt and calcium elements is prepared by a coprecipitation method, and then the solid is calcined with KOH solid to obtain the catalyst.

3. The method according to claim 2, characterized in that: The molar ratio of the magnesium element to the aluminum element is 2:1 to 4:1; The molar amount of the cobalt element is 1.8-2.2 times that of the aluminum element; The molar amount of the calcium element is 5%-15% of the aluminum element; and / or The mass ratio of the KOH solid to the solid containing magnesium, aluminum, cobalt and calcium elements is 2:1 to 4:

1.

4. The method according to claim 2 or 3, comprising the following steps: a) dissolving magnesium salt, aluminum salt and cobalt salt in water to prepare liquid A; b) dissolving one or more of an alkali metal hydroxide, an alkali metal carbonate and an alkali metal bicarbonate in water to form a buffer solution, and adding a calcium salt under stirring to form a B solution, wherein the B solution is stirred without precipitation; c) adding the A solution and the B solution to water simultaneously to perform a coprecipitation reaction to obtain a C slurry, and drying the C slurry to obtain a D solid; d) grinding KOH solid and the D solid together and then calcining to obtain the catalyst.

5. The method according to claim 4, characterized in that: In step a), the magnesium salt is selected from one or more of magnesium chloride, magnesium nitrate, magnesium sulfate or their hydrates; the aluminum salt is selected from one or more of aluminum chloride, aluminum nitrate, aluminum sulfate or their hydrates; the cobalt salt is selected from one or more of cobalt chloride, cobalt nitrate, cobalt sulfate or their hydrates.

6. The method according to claim 4 or 5, characterized in that: In step b), the alkali metal hydroxide is selected from one or more of sodium hydroxide and potassium hydroxide; the alkali metal carbonate and the alkali metal bicarbonate are selected from one or more of sodium carbonate, sodium bicarbonate, potassium carbonate and potassium bicarbonate; and the calcium salt is selected from one or more of calcium carbonate, calcium nitrate and calcium chloride.

7. The method according to any one of claims 4 to 6, characterized in that: In step c), the coprecipitation reaction temperature is 60-100°C.

8. The method according to any one of claims 4 to 7, characterized in that: In step d), the calcination temperature is 600-900°C.

9. Use of the catalyst according to claim 1 or the catalyst prepared by the method according to any one of claims 2 to 8 in catalytic synthesis of nonionic surfactants.

10. The use according to claim 9, characterized in that: The nonionic surfactant is prepared by using the catalyst to catalyze the ring-opening polymerization reaction of an epoxy compound.

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