KR20140092943A - Preparation method of lignosulfonate, lignosulfonate prepared by the method, and admixture and concrete comprising lignosulfonate - Google Patents

Abstract

A method for preparing ligonosulfonate comprises the steps of: preparing lignin derived by hydrolyzing lignocellulosic biomass with acid; and sulfonating the lignin at temperatures higher than 130°C. Provided are the preparation method of lignosulfonate in which, during the sulfonating step, 0.6-2.0 mole of sulfite or bisulfite admixture is added per 200 g of the lignin, and the sulfonating step is carried out at less than pH 13, lignosulfonate prepared thereby, and an admixture and a concrete comprising the lignosulfonate.

Description

Preparation method of lignosulfonate, lignosulfonate prepared by the method, and admixture and lignosulfonate containing lignosulfonate prepared by the above method, and admixture and concrete containing the same,

Lignosulfonates, lignosulfonates prepared by the above method, and compositions and concrete containing the same.

Lignin is a natural polymer as a by-product produced in the process of producing pulp using wood such as sulfite pulping process and kraft pulping process.

The lignin obtained in the pulp process contains a hydrophilic functional group such as a sulfite group, a hydroxyl group and a carboxyl group, and has high solubility and is easy to handle. Therefore, a sulfonation process was added to prepare lignosulfonate.

On the other hand, lignin can also be obtained as a by-product in the process of producing sugar through hydrolysis of wood. Since the lignin obtained in the hydrolysis process has undergone the recondensation process to increase the carbon-carbon bond, the molecular weight is increased and the chemical reactivity is lower than that of the lignin obtained in the pulp process, making it unsuitable for use in the production of lignosulfonates.

Therefore, there is a need for a method for effectively producing lignosulfonates from lignin obtained in the hydrolysis process.

One aspect is to provide a process for preparing a new lignosulfonate.

Another aspect is to provide a lignosulfonate prepared by the above method.

Another aspect is to provide an admixture comprising the lignosulfonate.

Another aspect is to provide a concrete comprising the lignosulfonate.

According to one aspect,

Preparing a lignin obtained by hydrolyzing lignocellulosic biomass with an acid; And

Sulfonating said lignin at a temperature of at least < RTI ID = 0.0 > 130 C, <

There is provided a process for producing a lignosulfonate in which 0.6 to 2.0 moles of sulfite or bisulfite compound is added per 200 g of lignin in the sulfonation step.

According to another aspect,

A lignosulfonate prepared by the above method is provided.

According to another aspect,

An admixture comprising the lignosulfonate is provided.

According to another aspect

A concrete containing the lignosulfonate is provided.

According to one aspect, lignosulfonate can be prepared with high yield by sulfonating lignin obtained by hydrolysis at a high temperature.

Hereinafter, a method for producing a lignosulfonate according to an exemplary embodiment, a lignosulfonate prepared by the method, and an admixture and a concrete containing the lignosulfonate will be described in more detail.

According to one embodiment, there is provided a method for preparing a lignosulfonate comprising: preparing lignin obtained by hydrolyzing a lignocellulosic biomass with an acid; And sulfonating the lignin at a temperature of 130 ° C or higher, wherein from 0.6 to 2.0 moles of sulfite or bisulfite compound per 200 g of lignin is added during the sulfonation step.

In this method, lignin obtained from the hydrolysis product of woody biomass can be sulfonated at a high temperature of 130 ° C or higher using a predetermined amount of a sulfite-based compound to produce lignosulfonate in a high yield.

If the sulfonation temperature is lower than 130 캜, the yield of the lignosulfonate may be lowered. If the sulphonation temperature is excessively high in the above production method, expensive steam may be required, which may be uneconomical. For example, in the above production process, the sulfonation step may be carried out at a temperature of 140 ° C to 190 ° C. For example, in the above production process, the sulfonation step can be carried out at a temperature of 160 ° C to 190 ° C. In the above production process, the sulfonation step can be carried out at a temperature of 170 ° C to 190 ° C. In the above production process, the sulfonation step may be carried out at a temperature of 180 ° C to 190 ° C.

 If the content of the sulfite compound added per 200 g of lignin is less than 0.6 mol, the yield of the lignosulfonate may be lowered. If the content of the sulfite-based compound added per 200 g of lignin exceeds 2.0 mol, the yield of the lignosulfonate may be lowered. For example, in the above production method, the content of the sulfite-based compound added per 200 g of lignin may be 0.6 mol to 1.5 mol. For example, in the above production method, the content of the sulfite-based compound added per 200 g of lignin may be 0.6 mol to 1.0 mol. For example, in the above production method, the content of the sulfite-based compound added per 200 g of lignin may be 0.6 to 0.8 mol.

The sulfite compound to but one sodium sulfite (Na2SO3), sulfur dioxide / sodium hydroxide (SO ₂ / NaOH), is not necessarily limited to, both a compound that enables the sulfonation of lignin in the art It is possible.

In the above production process, the sulfonation step can be carried out at a pressure of more than 10 bar to a pressure of 20 bar. If the pressure is below 10 ba, it may be difficult to maintain the temperature required in the sulfonation step. If the pressure exceeds 20 bar, a separate high-pressure reactor is required, which may be uneconomical. For example, in the above process, the sulfonation step can be carried out at a pressure of 15 bar to 20 bar. For example, in the above process, the sulfonation step can be carried out at a pressure of 18 bar to 20 bar.

In the above production process, the sulfonation step may be carried out at a pH of 3 to 11. If the pH is less than 3, a step of neutralizing the produced lignosulfonate is further required. If the pH is more than 11, a high viscosity lignosulfonate can be prepared. For example, in the above production process, the sulfonation step can be carried out at a pH of from 4 to 10. For example, in the above process, the sulfonation step may be carried out at a pH of from 6 to 8.

In the above production method, the sulfonation step can be carried out for 2 hours or more. For example, the sulfonation step can be carried out for 2 to 3 hours. The time at which the sulfonation step is performed is the time at which the sulfonation reaction takes place. If the sulfonation reaction time is less than 2 hours, the yield of the lignosulfonate may be lowered. When the sulfonation reaction time is 3 hours or more, the yield is not greatly changed.

The content of lignin contained in the solution used in the sulfonation step, for example, the aqueous solution, in the above production method may be 15% by weight or less. For example, the content of lignin in the solution used in the sulfonation step may be up to 10% by weight. If the content of lignin contained in the solution used in the sulfonation step is 15 wt% or more, the yield of the lignosulfonate may be lowered.

The method may further include methylolysis of lignin before the sulfonation step.

By further including methylolization of the lignin, the yield of lignosulfonate can be further improved. The addition of a methylol group to the benzene ring of the lignin by the methylol may increase the functionality and further improve the reactivity in the sulfonation step.

In the methylolization step, from 0.2 mol to 1.0 mol of formaldehyde per 200 g of lignin may be added. If the formaldehyde content is less than 0.2 mol, methylolization may be insignificant and it may be difficult to improve the yield of the lignosulfonate. If the formaldehyde content is more than 1.0 mol, unreacted formaldehyde may remain and side reactions may occur. For example, 0.3 to 0.6 mol of formaldehyde per 200 g of lignin may be added during the methylolization step.

The methylolization step may be carried out at pH 11-13. If the pH is less than 11, the methylol reaction may be insignificant. For example, the methylol step may be carried out at a pH of from 11 to 12.5. For example, the methylol step may be carried out at a pH of from 11 to 12.

The methylolization step may be carried out at a temperature of 70 < 0 > C or higher. If the methylolization step is carried out at a temperature lower than 70 ° C., the methylolization reaction may not proceed. For example, the methylolization step may be carried out at a temperature of 70 ° C to 85 ° C. For example, the methylolization step can be carried out at a temperature of 70 ° C to 80 ° C. For example, the methylolization step may be carried out at a temperature of from 70 ° C to 75 ° C.

In the above manufacturing method, the step of impregnating the basic solvent with lignin at 60 DEG C or more may be further included before the methylolization step. By additionally impregnating the basic solvent with the lignin, the benzene ring contained in the lignin can be ionized to increase the reaction efficiency. The pH of the basic solution may be from 11 to 12, but it is not limited to such a range, and any condition can be used as long as it can partially or wholly ionize the benzene ring contained in lignin. The time for impregnating the basic solvent with lignin is not particularly limited, and it is possible to ionize the benzene ring contained in lignin partially or wholly.

The method may further include a step of acidifying the lignin after the methylolization step. The step of acidifying the lignin is a step of lowering the pH of the reaction solution in which methylolization has been completed to 2 or less. In the step of acidifying the lignin, the metal salt of the hydroxyl group linked to the benzene ring of lignin is acidified to the hydroxy group.

The acidified lignin is allowed to stand for 30 minutes or more at a temperature of 70 ° C or more to be solidified, cooled to room temperature, filtered, washed and dried to prepare methylol lignin.

In the above method, the step of impregnating the water with lignin may be further included before the methylolization step. Since lignin obtained by hydrolysis is a solid phase which is not soluble in water, it can be impregnated with water to increase the reactivity in the subsequent reaction. May be impregnated with water at a ratio of 200 to 400 parts by weight of water to 100 parts by weight of lignin.

The step of impregnating the lignin with water can be carried out at a temperature of 20 to 70 캜 for 8 to 24 hours, but not always limited to these conditions, and any impregnation condition capable of improving the yield of the lignosulfonate is possible.

The acid hydrolyzing the woody biomass in the above production method may be sulfuric acid. The sulfuric acid may be concentrated sulfuric acid having a concentration of 20% or more. Preferably, the hydrolysis can be effected effectively when the sulfuric acid concentration is 65% or more.

The yield of lignosulfonates prepared using lignin obtained by hydrolysis with sulfuric acid may be 30% by weight or more. For example, the yield of lignosulfonates prepared using lignin obtained in hydrolysis using sulfuric acid may be at least 35% by weight.

In the above production method, the acid which hydrolyzes the woody biomass may be hydrochloric acid. The hydrochloric acid may be concentrated hydrochloric acid having a concentration of 20% or more. Preferably, the hydrolysis can be effected effectively when the concentration of hydrochloric acid is 39% or more.

The yield of lignosulfonate produced using lignin obtained by hydrolysis with hydrochloric acid may be 50% by weight or more. For example, the yield of lignosulfonate produced using lignin obtained in hydrolysis with hydrochloric acid may be at least 60% by weight. For example, the yield of lignosulfonates prepared using lignin obtained in hydrolysis with hydrochloric acid may be at least 70% by weight. For example, the yield of lignosulfonates prepared using lignin obtained in the hydrolysis using hydrochloric acid may be 80% by weight or more. For example, the yield of lignosulfonate produced using lignin obtained in the hydrolysis using hydrochloric acid may be 90% by weight or more. For example, the yield of lignosulfonate produced using lignin obtained by hydrolysis with hydrochloric acid may be 95% by weight or more.

A lignosulfonate according to another embodiment is prepared by the above-described method. It was confirmed that the lignosulfonate derived from the strong acid lignin produced by the above-mentioned method had the same functional group as the lignosulfonate derived from kraft lignin when analyzed by FT-IR. However, since the carbon-carbon bond is increased through the recondensation process in the hydrolysis process by the strong acid, the molecular weight is larger than that of the conventional lignosulfonate derived from kraft lignin.

The composition according to another embodiment includes a lignosulfonate prepared by the above-described method. The composition may be, for example, an admixture for the production of concrete. The admixture may substantially serve as an air entraining and reducing water agent.

The concrete according to another embodiment includes the lignosulfonate produced by the above-described method. Since the concrete contains lignosulfonate, the minute bubbles are dispersed evenly in the concrete, so that the cracks of the concrete caused by the ice and the like can be prevented by the elasticity of the bubbles, so that the durability of the concrete can be improved.

In addition, the existing lignin-derived lignosulfonate from kraft lignin is used as a concrete admixture at a solid content of 50%. The lignosulfonate derived from the strong acid lignin of the present invention requires a smaller amount. In a specific embodiment of the present invention, the lignosulfonate derived from lignin strongly acidic acid of the present invention has a solid content of about 40% (approximately 30% by weight of lignosulfonate) and satisfies the concrete admixture standard without using any conventional AE agent.

The present invention will be described in more detail by way of the following examples and comparative examples. However, the examples are for illustrating the present invention, and the scope of the present invention is not limited thereto.

(Preparation of lignosulfonate using lignin sulfate)

Example 1

(Step of preparing lignin sulfate)

Calliandra was used as a lignocellulosic biomass. The Caliandra wood was mixed with 72% sulfuric acid at a ratio of 1: 2 (w / v), and the mixture was thoroughly stirred at 30 ° C for 2 hours, subjected to primary hydrolysis, diluted with 30% Followed by thoroughly stirring at 85 캜 for 3 hours and secondary saccharification proceeded to prepare a sugar solution containing lignin.

The solution was filtered using a filter paper (ADVANTEC No. 5B) to separate the lignin from the solution, washed until the pH of the lignin became neutral, and then dried in an oven at 70 ° C to obtain lignin (hereinafter referred to as sulfuric acid- hydrolytic lignin)) was prepared.

The remaining sugar content in the lignin sulfate obtained through this process was less than 5%.

(Methylol step)

The lignin sulfate and water were mixed at a ratio of 1: 3 (w / v), and the mixture was stirred at room temperature for 24 hours to immerse the lignin sulfate in water.

Next, a 50% sodium hydroxide (NaOH) solution was added to the solution in which the lignin sulfate was immersed to prepare a basic solution having a pH of 11 to 12.

Subsequently, water was added to the basic solution so that the ratio of lignin sulfate to water was 1: 4 (w / v), and the mixture was heated to 70 ° C.

To the heated solution, 0.6 mol of formaldehyde (35% solution) was added to 200 g of lignin sulfate, and the mixture was stirred at 70 ° C for 2 hours to conduct the methylol reaction.

After the completion of the reaction, 72% sulfuric acid was added to the reaction solution to adjust the pH of the reaction solution to 2, and the stirring was stopped to acidify the lignin sulfate.

The solution containing the acidified sulphate lignin was coagulated at 85 ° C for 30 minutes, cooled to room temperature, filtered, washed and dried to obtain methylolated sulphate lignin in 95% yield.

(Sulfonation step)

200 g of methylated lignin sulfate was dispersed in water at a solid content of 9% and 1.0 mol of sodium sulfite (Na ₂ SO ₃ ) was added to completely dissolve the solution. The pH of the solution in which the lignin sulfate was dissolved using 72% sulfuric acid and / or 50% sodium hydroxide solution was adjusted to 7.0. The pH-adjusted solution was allowed to stand at 100 ° C and 10 bar for 2 hours to immerse the methylolated sulphate lignin in the solution. Subsequently, the temperature of the immersed solution was increased to 190 ° C, the pressure was increased to 20 bar, and the solution was stirred for 2 hours to conduct the sulfonation reaction.

After the reaction was terminated, the solution was rapidly cooled and then the unreacted residue was removed by centrifugation to obtain a solution containing lignosulfonate.

The obtained lignosulfonate solution was quantitatively / qualitatively analyzed using a UV / Vis spectrometer to calculate the yield of lignosulfonate production. As a standard sample, a powdery lignosulfonate with a purity of 41% was used.

Example 2

Lignosulfonate was prepared in the same manner as in Example 1, except that the content of sodium sulfite (Na ₂ SO ₃ ) added in the sulfonation step was changed to 0.6 mol.

Example 3

The same procedure as in Example 1 was carried out except that the content of sodium sulfite (Na ₂ SO ₃ ) added in the sulfonation step was changed to 0.6 mol and the pressure during the sulfonation reaction was changed to 10 bar, .

Example 4

The lignosulfonate was prepared in the same manner as in Example 1, except that the pH of the solution in which the methylolated lignin sulfate added in the sulfonation step was dissolved was changed to 10.9.

(Examples 5 to 7: Methylol step is omitted)

Example 5

The methylolization step was omitted and the methylol-free lignin sulfate was used as it was,

Lignosulfonate was prepared in the same manner as in Example 1, except that the pH of the solution in which lignin sulfate dissolved in the sulfonation step was changed to 3.9.

Example 6

The methylolization step was omitted and the methylol-free lignin sulfate was used as it was,

Lignosulfonate was prepared in the same manner as in Example 1, except that the pH of the solution in which lignin sulfate dissolved in the sulfonation step was changed to 7.0.

Example 7

The methylolization step was omitted and the methylol-free lignin sulfate was used as it was,

Lignosulfonate was prepared in the same manner as in Example 1, except that the pH of the solution in which lignin sulfate dissolved in the sulfonation step was changed to 12.7.

Experimental results using lignin sulfate are summarized in Table 1 below.

ingredient Presence or absence of methylol step The pH of the solution used in the sulfonation step The sodium sulfite content used in the sulfonation step
[mole] Sulfonation reaction pressure
[bar] Lignosulfonate yield
[wt.%] Example 1 U 7.0 1.0 20 14.0 Example 2 U 7.0 0.6 20 39.9 Example 3 U 7.0 0.6 10 17.1 Example 4 U 10.9 0.6 20 38.3 Example 5 radish 3.9 1.0 20 5.6 Example 6 radish 7.0 1.0 20 9.9 Example 7 radish 12.7 1.0 20 -

As shown in Table 1, lignosulfonates were obtained in Examples 1 to 7. However, in Example 7, it was judged that lignosulfonate was obtained although unreacted lignin was mixed and the exact content could not be measured.

The yield of lignosulfonates was further improved in Examples 1 to 4 which additionally included a methylolization step.

Since the lignosulfonates of Examples 4 and 7 are basic, neutralization is necessary when they are used in concrete admixtures and the like.

(Preparation of lignosulfonate using lignin hydrochloride)

Example 8

(Lignin hydrochloride manufacturing step)

Calliandra was used as a lignocellulosic biomass. Hydrogen chloride gas was added to 35 ~ 37% hydrochloric acid concentration to prepare 42% hydrochloric acid. The Caliandra wood was mixed with 42% sulfuric acid at a ratio of 1: 5 (w / v), and the mixture was thoroughly stirred at 20 ° C for 5 hours. After hydrolysis was carried out, excess water was added to dilute hydrochloric acid To prepare a liquid sugar solution containing lignin.

After filtration using a stainless steel sieve (325-ASTM) to separate the lignin from the sugar solution, the lignin was washed until the pH of the lignin became neutral, and then dried in an oven at 70 DEG C to obtain lignin Hydrochloric acid-hydrolytic lignin) was prepared.

The remaining sugar content in the lignin hydrochloride obtained through this process was less than 3%, and about 1% of chlorine (Cl) remained.

(Methylol step)

The lignin hydrochloride and water were mixed at a ratio of 1: 3 (w / v), and then stirred at room temperature for 24 hours to immerse the lignin hydrochloride in water.

Subsequently, 50% sodium hydroxide (NaOH) solution was added to the solution in which the lignin hydrochloride was immersed to prepare a basic solution having a pH of 11 to 12.

Subsequently, water was added to the basic solution so that the ratio of lignin hydrochloride to water was 1: 4 (w / v), and the mixture was heated to 70 ° C.

To the heated solution, 0.6 mol of formaldehyde (35% solution) was added to 200 g of lignin hydrochloride, followed by stirring at 70 ° C for 2 hours to conduct the methylol reaction.

After completion of the reaction, 72% sulfuric acid was added to the reaction solution to adjust the pH of the reaction solution to 2, and stirring was stopped to acidify the lignin hydrochloride.

The solution containing the acidified lignin hydrochloride was solidified at 85 ° C for 30 minutes, cooled to room temperature, filtered, washed and dried to obtain methylolated lignin hydrochloride in 95% yield.

(Sulfonation step)

After 200 g of methylated lignin hydrochloride was dispersed in water at a solids content of 9%, 0.6 mol of sodium sulfite (Na ₂ SO ₃ ) or sulfur dioxide / sodium hydroxide (SO ₂ / NaOH) was added to completely dissolve the solution Were prepared. The pH of the solution in which the lignin hydrochloride was dissolved was adjusted to 7.0 using 72% sulfuric acid and / or 50% sodium hydroxide solution. The pH-adjusted solution was allowed to stand at 100 ° C and 10 bar for 2 hours to immerse the methylolated lignin hydrochloride in the solution. Subsequently, the temperature of the immersed solution was increased to 190 ° C, the pressure was increased to 20 bar, and the solution was stirred for 2 hours to conduct the sulfonation reaction.

After the reaction was terminated, the solution was rapidly cooled and then the unreacted residue was removed by centrifugation to obtain a solution containing lignosulfonate.

The obtained lignosulfonate solution was quantitatively / qualitatively analyzed using a UV / Vis spectrometer to calculate the yield of lignosulfonate production. As a standard sample, a powdery lignosulfonate with a purity of 41% was used.

Example 9

The same procedure as in Example 8 was carried out except that the content of sodium sulfite (Na ₂ SO ₃ ) or sulfur dioxide / sodium hydroxide (SO ₂ / NaOH) added in the sulfonation step was changed to 0.8 mol, Sulfonate.

Example 10

The same procedure as in Example 8 was carried out except that the content of sodium sulfite (Na ₂ SO ₃ ) or sulfur dioxide / sodium hydroxide (SO ₂ / NaOH) added in the sulfonation step was changed to 1.0 mol, Sulfonate.

Example 11

Lignosulfonate was prepared in the same manner as in Example 8 except that the content of formaldehyde added at the methylolization step was changed to 0.3 mol.

Example 12

The formaldehyde content added in the methylol step was changed to 0.3 mole,

The same procedure as in Example 8 was carried out except that the content of sodium sulfite (Na ₂ SO ₃ ) or sulfur dioxide / sodium hydroxide (SO ₂ / NaOH) added in the sulfonation step was changed to 0.8 mol, Sulfonate.

Example 13

The formaldehyde content added in the methylol step was changed to 0.3 mole,

The same procedure as in Example 8 was carried out except that the content of sodium sulfite (Na ₂ SO ₃ ) or sulfur dioxide / sodium hydroxide (SO ₂ / NaOH) added in the sulfonation step was changed to 1.0 mol, Sulfonate.

Example 14

The formaldehyde content added in the methylol step was changed to 0.3 mole,

The content of sodium sulfite (Na ₂ SO ₃ ) or sulfur dioxide / sodium hydroxide (SO ₂ / NaOH) added in the sulfonation step was changed to 0.8 mol,

Lignosulfonate was prepared in the same manner as in Example 8 except that the sulfonation reaction temperature was changed to 180 캜.

Example 15

The formaldehyde content added in the methylol step was changed to 0.3 mole,

The content of sodium sulfite (Na ₂ SO ₃ ) or sulfur dioxide / sodium hydroxide (SO ₂ / NaOH) added in the sulfonation step was changed to 0.8 mol,

Lignosulfonate was prepared in the same manner as in Example 8 except that the sulfonation reaction temperature was changed to 170 캜.

Example 16

The formaldehyde content added in the methylol step was changed to 0.3 mole,

The content of sodium sulfite (Na ₂ SO ₃ ) or sulfur dioxide / sodium hydroxide (SO ₂ / NaOH) added in the sulfonation step was changed to 0.8 mol,

Lignosulfonate was prepared in the same manner as in Example 8 except that the sulfonation reaction temperature was changed to 160 캜.

Example 17

The formaldehyde content added in the methylol step was changed to 0.3 mole,

The content of sodium sulfite (Na ₂ SO ₃ ) or sulfur dioxide / sodium hydroxide (SO ₂ / NaOH) added in the sulfonation step was changed to 0.8 mol,

Lignosulfonate was prepared in the same manner as in Example 8 except that the sulfonation reaction temperature was changed to 130 캜.

(Examples 18 to 22, Comparative Examples 1 and 2: Methylolization step is omitted)

Example 18

Lignosulfonate was prepared in the same manner as in Example 8 except that the methylolization step was omitted and lignin hydrochloride which was not methylated was used as it was.

Example 19

The methylolization step was omitted, and the methylol-free lignin hydrochloride was used as it was,

Lignosulfonate was prepared in the same manner as in Example 8 except that the content of sodium sulfite (Na ₂ SO ₃ ) added in the sulfonation step was changed to 1.0 mol.

Example 20

The methylolization step was omitted, and the methylol-free lignin hydrochloride was used as it was,

Lignosulfonate was prepared in the same manner as in Example 8 except that the content of sodium sulfite (Na ₂ SO ₃ ) added in the sulfonation step was changed to 2.0 mol.

Example 21

The methylolization step was omitted, and the methylol-free lignin hydrochloride was used as it was,

The content of sodium sulfite (Na ₂ SO ₃ ) added in the sulfonation step was changed to 1.0 mol,

Lignosulfonate was prepared in the same manner as in Example 8, except that the solid content of lignin hydrochloride added to the solution used in the sulfonation step was changed to 17%.

Example 22

The methylolization step was omitted, and the methylol-free lignin hydrochloride was used as it was,

The content of sodium sulfite (Na ₂ SO ₃ ) added in the sulfonation step was changed to 1.0 mol,

The lignosulfonate was prepared in the same manner as in Example 8, except that the solid content of lignin hydrochloride added to the solution used in the sulfonation step was changed to 25%.

Comparative Example 1

The methylolization step was omitted, and the methylol-free lignin hydrochloride was used as it was,

Lignosulfonate was prepared in the same manner as in Example 8, except that sodium sulfite (Na ₂ SO ₃ ) was not added in the sulfonation step.

Comparative Example 2

The methylolization step was omitted, and the methylol-free lignin hydrochloride was used as it was,

Lignosulfonate was prepared in the same manner as in Example 8 except that the sodium sulfite (Na ₂ SO ₃ ) content added in the sulfonation step was changed to 0.2 mol.

Experimental results using lignin hydrochloride are summarized in Table 2 as experimental conditions.

ingredient Presence or absence of methylol Formaldehyde content
[mole] Lignin content
[wt%] Sulfonation reaction temperature
[° C] Sodium sulfite content
[mole] Lignosulfonate yield
[wt.%] Example 8 U 0.6 9 190 0.6 53.2 Example 9 U 0.6 9 190 0.8 75.8 Example 10 U 0.6 9 190 1.0 99.1 Example 11 U 0.3 9 190 0.6 54.9 Example 12 U 0.3 9 190 0.8 92.6 Example 13 U 0.3 9 190 1.0 95.6 Example 14 U 0.3 9 180 0.8 39.6 Example 15 U 0.3 9 170 0.8 26.5 Example 16 U 0.3 9 160 0.8 18.1 Example 17 U 0.3 9 130 0.8 6.8 Example 18 radish - 9 190 0.6 57.5 Example 19 radish - 9 190 1.0 82.9 Example 20 radish - 9 190 2.0 81.3 Example 21 radish - 17 190 1.0 56.8 Example 22 radish - 25 190 1.0 48.6 Comparative Example 1 radish - 9 190 0.0 0.0 Comparative Example 2 radish - 9 190 0.2 0.0

As shown in Table 2, lignosulfonates were obtained in Examples 8 to 22.

On the other hand, lignosulfonates were not obtained in Comparative Examples 1 and 2 in which the amount of sulfite added was low.

The yields of lignosulfonates were generally improved in Examples 8 to 17, which additionally included the methylolization step, as compared to those of Examples 18 to 22, in which there was no methylolization step.

(Preparation of concrete admixture)

Example 23

The solution containing the lignosulfonate prepared in Example 19 was concentrated to prepare a solution having a lignosulfonate content of 15.7% by weight (solids content: 49.6% by weight).

Example 24

The solution containing the lignosulfonate prepared in Example 10 was concentrated to prepare a solution having a lignosulfonate content of 32% by weight (solids content: 41.2%).

Evaluation Example 1: Concrete admixture suitability evaluation

Concrete was prepared according to the KS F 2560 method for the admixtures prepared in Examples 23 and 24, and the suitability as a concrete admixture was evaluated.

The concrete containing the admixture of Example 23 was prepared by mixing 177 g of water, 320 g of cement, 1105 g of fine aggregate, 1460 g of coarse aggregate, admixture and commercial AE agent. The admixture was 0.5% of the cement content, 0.02% Was added.

The concrete containing the admixture of Example 24 was prepared by mixing 142 g of water, 320 g of cement, 867 g of fine aggregate, 1091 g of coarse aggregate, and an admixture, and 0.5% of the cement content was added to the admixture. That is, no commercial AE agent was used.

The evaluation results are shown in Table 3 below.

Evaluation items AE water reducing agent _ standard of quality standard Example 23 Example 24 Water retention rate [%] over 10 16 11 Ratio of bleeding amount [%] 0.670 or less 54 57 Difference in condensation time
[minute] Fresh -60 to +90 +35 +30 closing -60 to +90 +45 +30 Ratio of compressive strength
[%] 3 days 115 or more 124 138 7 days 110 or more 119 133 18th 110 or more 114 126 Resistance to freezing and thawing
[State dynamic modulus,%] More than 80 88 - Over time variation
[60 minutes] Slump [mm] 50 50 Air volume [%] 0.4 0.3

As shown in Table 3, the admixture of Examples 23 and 24 showed that the concrete admixture could be used satisfying the quality standard of the AE water reducing agent standard.

Particularly, Example 24 satisfied the concrete admixture standard without using the conventional AE agent.

Claims (20)

Preparing a lignin obtained by hydrolyzing lignocellulosic biomass with an acid; And
Sulfonating said lignin at a temperature of at least < RTI ID = 0.0 > 130 C, <
Wherein from 0.6 to 2.0 moles of sulfite or bisulfite compound per 200 g of lignin is added in said sulfonating step. The process according to claim 1, wherein the sulfonation step is carried out at a temperature of from 140 캜 to 190 캜. The process according to claim 1, wherein the sulfonation step is carried out at a pressure in excess of 10 bar to 20 bar. The process according to claim 1, wherein the sulfonation step is carried out at a pH of from 3 to 11. The process according to claim 1, wherein the sulfonation step is performed for at least 2 hours. The method according to claim 1,
Further comprising the step of methylating lignin. 7. The process according to claim 6, wherein 0.2 to 1.0 mole of formaldehyde is added per 200 g of lignin in said methylolization step. 7. The process according to claim 6, wherein said methylolization step is carried out at pH 11-13. 7. The process according to claim 6, wherein the methylolization step is carried out at a temperature of at least 70 < 0 > C. 7. The method of claim 6,
Further comprising the step of impregnating the lignin with a basic solvent at 60 DEG C or higher. 7. The method of claim 6, wherein after the methylolization step
Further comprising the step of acidifying said lignin. 7. The method of claim 6, wherein, prior to the methylolization step,
≪ / RTI > further comprising impregnating the lignin with water. 13. The method according to claim 12, wherein the step of impregnating the water is carried out at a temperature of 20 to 70 DEG C for 8 to 24 hours. The process according to claim 1, wherein the acid is sulfuric acid. 15. The process according to claim 14, wherein the yield of the lignosulfonate is at least 30% by weight. The method according to claim 1, wherein the acid is hydrochloric acid. The process according to claim 16, wherein the yield of the lignosulfonate is at least 50% by weight. 17. A lignosulfonate prepared by any one of claims 1 to 17. 19. An admixture comprising a lignosulfonate prepared by any one of claims 1 to 17. A concrete comprising a lignosulfonate produced by any one of claims 1 to 17.