CS262986B1 - Continuous preparation of mixed paste based on sulfoacids and fatty acid soaps for powder detergent production - Google Patents

Abstract

A continuous method for preparing a mixed paste based on a mixture of salts of sulfonic acids and soaps of fatty acids for the production of powder detergents is carried out by neutralizing sulfonic acids and fatty acids with a carbon chain length of Cg to O™ in a molar ratio of 1 to 12 5 1. Neutralization is carried out in three stages with an average retention time in individual stages of 0.1 to 30 sec under a flow regime corresponding to a Re number of 10 to 400. In the first stage, sulfonic acid is introduced into the flowing aqueous alkali solution in a molar ratio of 1 to 0.2 to 0.8. In the second stage, the resulting reaction mixture is treated with fatty acid, with a molar ratio of fatty acid to free alkalinity of 0.3 to 0.9:1. In the third stage, the resulting reaction mixture is treated with sulfonic acid in a molar ratio of free alkalinity of 0.4 to 1:1. Alkylaryl, alkenyl or alkyl sulfonic acids with 8 to 30 carbons in the chain are used as sulfonic acids. An aqueous solution of sodium, potassium or ammonium hydroxide or mono-, di- or triethanolamine with a concentration of 3 to 50% by weight is used as alkali. A continuous process for preparing a mixed paste based on mixtures of salts of sulfonic acids and fatty acid soaps for the production of powdered detergents is useful in the chemical industry.

Description

Continuous process for preparing a mixed paste based on salts of sulfonic acids and fatty acid soaps for the production of powder detergents

A continuous method for preparing a mixed paste based on a mixture of salts of sulfonic acids and soaps of fatty acids for the production of powder detergents is carried out by neutralizing sulfonic acids and fatty acids with a carbon chain length of Cg to O™ in a molar ratio of 1 to 12 5 1. Neutralization is carried out in three stages with an average retention time in individual stages of 0.1 to 30 sec under a flow regime corresponding to a Re number of 10 to 400. In the first stage, sulfonic acid is introduced into the flowing aqueous alkali solution in a molar ratio of 1 to 0.2 to 0.8.

In the second stage, the resulting reaction mixture is treated with fatty acid, with a molar ratio of fatty acid to free alkalinity of 0.3 to 0.9:1. In the third stage, the resulting reaction mixture is treated with sulfonic acid in a molar ratio of free alkalinity of 0.4 to 1:1. Alkylaryl, alkenyl or alkyl sulfonic acids with 8 to 30 carbons in the chain are used as sulfonic acids. An aqueous solution of sodium, potassium or ammonium hydroxide or mono-, di- or triethanolamine with a concentration of 3 to 50% by weight is used as alkali. A continuous process for preparing a mixed paste based on mixtures of salts of sulfonic acids and fatty acid soaps for the production of powdered detergents is useful in the chemical industry.

262,988

The invention relates to a continuous process for preparing a mixed paste based on salts of sulfonic acids and fatty acid soaps for the production of powder detergents.

One of the basic raw materials for the preparation of powder detergents is the so-called mixed paste, which is a neutralized mixture of the acidic form of a synthetic surfactant and a fatty acid. The previously known processes for the preparation of mixed active substances use continuously or discontinuously operating reactors equipped with mechanical stirrers. In the reactors, neutralization occurs with simultaneous dosing of the acidic form of a synthetic surfactant, fatty acid and neutralizing agent.

Due to the exothermic nature of the neutralization reaction, it is necessary that the neutralization reactor be equipped with cooling. In this neutralization process, a number of factors contribute to the quality of the mixed active substance produced.

The possibility of aerating air with mechanical stirrers results in foaming of the reaction mixture, thereby increasing its viscosity. The increased viscosity of the reaction mixture, together with the air present, adversely affects the quantitative course of neutralization _# , especially of fatty acids. The unreacted proportion of fatty acid in the reaction mixture is manifested in the final product by a decrease in the pH value.

By simultaneously dosing all reaction components, due to the limited intensity of mixing, a local neutralization process occurs.

Local reaction rate along with the release of reaction heat has an adverse effect on the color change of the final product.

- 2 262 98B

Another shortcoming of the previously used process for preparing a mixed active agent by continuous neutralization of acidic forms of synthetic surfactants and fatty acids is the low efficiency of the process due to the considerable residence time of the reaction mixture in the neutralizers, which is on the order of tens of minutes.

The above-mentioned shortcomings are eliminated by a continuous process for preparing a mixed paste based on a mixture of salts of sulfonic acids and soaps of fatty acids, for the production of powder detergents, carried out by neutralizing sulfonic acids and fatty acids with a carbon chain length of Cq to C30 in a molar ratio of 1 to 12:1 according to the invention. Its essence lies in the fact that neutralization is carried out in three stages with an average retention time in individual stages of 0.1 to 50 seconds under a flow regime corresponding to an Re number of 10 to 400, whereby in the first stage, sulfonic acid is introduced into the flowing aqueous alkali solution in a molar ratio of 1:0.2 to 0.8, in the second stage, the resulting reaction mixture is treated with fatty acid, whereby the molar ratio of fatty acid to free alkali is 0.3 to 0.9:1, in the third stage, the resulting reaction mixture is treated with sulfonic acid in a molar ratio of 0.4 to 1:1 to free alkalinity.

As sulfonic acids, it is suitable to use alkylaryl, alkenyl or alkylsulfonic acids with 8 to 30 carbons in the chain. As alkali, it is suitable to use an aqueous solution of sodium, potassium or ammonium hydroxide or mono-, di or triethanolamine with a concentration of 3 to 50% by weight.

The advantage of this method of preparing a mixed paste according to the invention is that by dosing the individual types of sulfonic acids and fatty acids into the stream of aqueous alkali solution in a suitable order, favorable conditions are created for the quantitative neutralization of the fatty acid. The course of neutralization in a closed system without access of air then results in obtaining a mixed active substance with a lower viscosity and density compared to classical neutralization procedures.

As a result of the gradual introduction of individual types of sulfonic acids and fatty acids into the aqueous alkali solution, such a distribution of the released reaction heat is also achieved that there is no need to cool the reaction mixture.

- 3,262,986

The method of preparing the mixed paste according to the invention is described with several examples and the resulting effect is explained by comparing the rheological properties and density with products prepared by the classical method in Table δ. 1.

Example 1

After homogenizing 98.3 kmol/h of water with 4 kmol/h of sodium hydroxide with a concentration of 40% by weight, 2 kmol/h of alkylsulfonic acid with 22 carbons in the chain were fed to the resulting continuous flow of aqueous alkali solution in the 1st stage of the static mixer. 1 kmol/h of fatty acid with a chain length of C1_2 was fed to the reaction mixture in the second stage of the static mixer, and 1 kmol/h of alkylsulfonic acid with 22 carbons in the chain was fed to the reaction mixture in the third stage of the static mixer. The residence time of the reaction mixture in the static mixer is 2 seconds and the Reynolds number for the flow of the reaction mixture is 110. A homogeneous mixed active substance with a temperature of 65 °C, a pH of 8.5, containing 30% by weight of sodium alkylsulfonate and 10% by weight of sodium soap is obtained.

Example 2

After mixing 76.8 kmol/h of water and 3 kmol/h of potassium hydroxide with a concentration of 40% by weight, 1.5 kmol/h of alkane sulfonic acid with 12 carbons in the chain was added to the resulting continuous stream of aqueous alkali solution in the 1st stage of the static mixer. 1 kmol/h of distilled fatty acid with a chain length of 12 carbons in the chain was fed to the reaction mixture in the 2nd stage of the static mixer, and 0.5 kmol/h of alkane sulfonic acid with 12 carbons in the chain was fed to the reaction mixture in the third stage of the static mixer. The residence time of the reaction mixture is 1.5 seconds, the Reynolds number for the flow of the reaction mixture is 60. A homogeneous transparent mixed active substance with a temperature of 60 °C, a pH of 9.6 and a content of 27.4% by weight of potassium alkane sulfonate and 18.7% by weight of potassium alkane sulfonate is obtained. potassium soap.

Example 3

After homogenizing 68 kmol/h of water, 4 kmol/h of hydroxide with a concentration of 40% by weight was fed to the resulting continuous aqueous alkali solution in the 1st stage of the static mixer at 2 kmol/h.

-alkenylsulfonic acids with 16 carbons in the chain. Up to 2nd degree

262,986

- 4 static mixer 1 kmol/h of a cleaved fatty acid with a chain length of C20 was fed to the reaction mixture ^and ^o the third stage of the static mixer 1 kmol/h of -alkenylsulfonic acid with 16 carbons in the chain was fed to the reaction mixture. The residence time of the reaction mixture in the static mixer is 0.8 seconds and the Reynolds number value for the flow of the reaction mixture is 100. The prepared mixed active substance contains 34.4 wt. % «έ -alkenylsulfonate sodium and 9.3 wt. % sodium soap. The temperature of the final product is 71 °C and the pH is 8.3.

Example 4

After homogenization of 60 kmol/h of water and 5 kmol/h of ammonium hydroxide with a concentration of 35% by weight, 4 kmol/h of alkylaryl sulfonic acid with 24 carbons in the chain were fed to the resulting continuous stream of aqueous solution in the first stage of the static mixer. 0.5 kmol/h of distilled fatty acid with a chain length of Οχθ was added to the reaction mixture in the second stage of the static mixer, and 0.5 kmol/h of alkylaryl sulfonic acid with 24 carbons in the chain was fed to the reaction mixture in the third stage of the static mixer. The residence time of the reaction mixture in the static mixer is 2.5 seconds and the Reynolds number for the flow of the reaction mixture is 180. A homogeneous mixed active substance with a content of 45.6% by weight of ammonium alkylaryl sulfonate and 4.4% by weight of ammonium alkylaryl sulfonate and 4.4% by weight of ammonium alkylaryl sulfonate is obtained. ammonium soap at a temperature of 68 °C and a pH of 8.9.

Table

Comparison of rheological properties and density of mixed paste prepared according to the new and classical procedure.

procedure example Κ n /kg/m^/ /Pa s ⁿ / / - /

T ................ M· .11-11—!! 1.-,-,--,--,.11,

classic 1 '1040 1.95 0.87 way 2 1100 2.58 0.86 5 1020 1.63 0.74 4 1080 2.32 0.90 way 1 1210 1.72 0.75 according to 0 1290 2.05 0.76 invention 3 1250 1.43 0.61 4 1240 í.,.36....... 0.80,

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The continuous process for preparing ^paste mixtures according to the invention is useful in the chemical industry.

Claims (1)

CLAIMS 1. A continuous process for the preparation of a mixed paste based on a mixture of salts of sulfo acids and fatty acid soaps for the production of powdered detergents, by neutralizing sulfo acids and fatty acids having a carbon chain length of C8 to G6 ^{in a} molar ratio of 1 to 12: 1. is carried out in three stages at a mean residence time of 0.1 to 50 seconds in individual stages with a flow regime corresponding to a Re number of 10 to 400, wherein in the first stage a sulfo acid is introduced in a molar ratio of 1: 0.2 to 0 In the second step, the resulting reaction mixture is treated with a fatty acid, wherein the molar ratio of fatty acid to free alkalinity is 0.5 to 0.9: 1, in the third step, the resulting reaction mixture is treated with a sulfo acid in a molar ratio to free alkalinity 0.4 to 1: 1. ?. 3. The process according to claim 1, wherein the sulfoacid is an alkylaryl, alkenyl or alkylsulfoacid having from 8 to 50 carbons in the chain. 5. The process according to claim 1, wherein the alkali is an aqueous solution of sodium, potassium or ammonium hydroxide or mono-, di- or triethanolamine in a concentration of 3 to 50% by weight.