KR20190003915A

KR20190003915A - A preparation method of modified lignin and fertilizer composition comprising the modified lignin

Info

Publication number: KR20190003915A
Application number: KR1020170083863A
Authority: KR
Inventors: 임종구
Original assignee: 지에스칼텍스 주식회사; 경상대학교산학협력단
Priority date: 2017-06-30
Filing date: 2017-06-30
Publication date: 2019-01-10
Also published as: KR101989796B1; WO2019004761A1

Abstract

The present invention relates to a preparation method of modified lignin, which comprises following steps: preparing a lignin solution by mixing hydrogen peroxide and a lignin cake; adding ferrous ions in the lignin solution; removing a supernatant after centrifugation of the lignin solution added with the ferrous ions; and drying a solid matter left after removing the supernatant. The lignin cake is prepared by acid hydrolysis of lignocellulosic biomass. The present invention also relates to a fertilizer composition comprising the modified lignin.

Description

TECHNICAL FIELD The present invention relates to a method for producing modified lignin and a fertilizer composition containing modified lignin,

The present invention relates to a method for producing modified lignin and a fertilizer composition comprising modified lignin.

Humic acid is a humic substance that dissolves only in the acidic state of pH 2 or higher, which is an organic matter other than organisms contained in the soil, and which is a brown or black acidic organic matter that remains in the humic substance but is not removed by the solvent. Humic acid accounts for more than 50% of the dissolved organic matter in the natural world, and affects the distribution of many substances in the soil depending on the degree of dissolution. Humic acid is nutritious and effective in promoting microbial growth and root growth of plants, and is a popular fertilizer source, especially in organic farming.

On the other hand, woody biomass is attracting attention as a new oil alternative resource, and woody biomass is composed of three main components: cellulose, hemicellulose and lignin. Cellulose and hemicellulose are carbohydrates that are glycosylated using enzymes or acids and then converted into industrially available forms through microbial fermentation. Lignin, on the other hand, has long been regarded as a product to be removed in the treatment of woody biomass. However, lignin accounts for a large part of the biomass content. In recent years, studies for utilizing such lignin have been actively conducted.

For example, Korean Patent No. 10-1188062 discloses a slow-release fertilizer which uniformly contains woody biomass and fertilizer. The lignin contained in the woody biomass is heated and pressurized The biomass is combined with the fertilizer to form a molded body. Korean Patent No. 10-0900455 discloses a binder for granulation of an inorganic fertilizer including bentonite, lignin, molasses, and the like. However, these techniques use lignin as an adhesive that mediates bonding between cellulose by heating and pressing, or as a component of a fertilizer binder, and does not use lignin as an active ingredient of fertilizer itself.

Accordingly, the inventors of the present invention confirmed that lignin is modified as a fertilizer when denaturing lignin by a specific method while studying a method of denaturing lignin for use as a fertilizer raw material having a high added value such as humic acid, and completed the present invention.

It is an object of the present invention to provide a method of denaturing lignin so that it can be utilized as a fertilizer.

It is still another object of the present invention to provide a fertilizer composition comprising the modified lignin.

In order to achieve the above object, the present invention provides a lignin modification method and a fertilizer composition containing modified lignin.

The present invention makes it possible to modify lignin having a low added value in the past and utilize it as an active ingredient of a fertilizer composition.

The present invention also provides a fertilizer composition having an excellent growth promoting effect on plants.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing a manufacturing process of a lignin cake. Fig.
Figure 2 shows the degree of whitening of plants in MS medium supplemented with NaCl.
Figure 3 shows the degree of whitening of plants in MS medium supplemented with humic acid and NaCl.
Figure 4 shows the degree of whitening of plants in MS medium supplemented with lignin and NaCl.
Figure 5 shows the degree of whitening of plants in MS medium supplemented with modified lignin (reacted with 0.1 g of FeSO4) and NaCl.
Figure 6 shows the degree of whitening of plants in MS medium supplemented with modified lignin (reacted with 0.5 g of FeSO4) and NaCl.
Figure 7 shows the degree of whitening of plants in MS medium supplemented with modified lignin (reacted with 0.7 g FeSO4) and NaCl.

According to the present invention,

Mixing hydrogen peroxide and a lignin cake to prepare a lignin solution;

Adding iron ions to the lignin solution;

Centrifuging the lignin solution to which the iron ions have been added, and removing the supernatant;

Removing the supernatant and drying the remaining solids,

Wherein the lignin cake is prepared by acid hydrolysis of woody biomass.

And a method for producing the modified lignin.

Further, according to the present invention,

And a fertilizer composition comprising the modified lignin of the present invention.

Hereinafter, the present invention will be described in detail.

Lignin cake

The lignin cake of the present invention is prepared by acid hydrolysis of woody biomass. Preferably, the lignin cake of the present invention is a solid phase portion obtained by adding water to a paste obtained by acid hydrolysis of woody biomass to hydrolyze and hydrolyzing the resulting hydrolyzate. The acid used for acid hydrolysis at this time is a strong acid, for example, sulfuric acid, hydrochloric acid, nitric acid, and the like. It is preferable that the acid is used in an amount of 72 to 78% by weight. Acid hydrolysis of the woody biomass results in a solid phase in a liquid phase and a paste state, in which the cellulose and hemicellulose are liquefied and the lignin remains in the paste. The paste is introduced into a hydrolysis apparatus together with water to adjust the acid concentration to 25 to 35% by weight. Thereafter, hydrolysis is carried out at 75 to 95 ° C for 30 minutes to 2 hours to convert cellulose and hemicellulose into hexane (such as glucose) and pentane (such as xylose). The hydrolyzate can be filtered (including filter presses) with both liquid and solid phases (paste), mixed with liquid (mixture of sugar and acid) and solid (lignin, unreacted biomass, trace sugar and acid mixture) Separate. The solid phase is dried to obtain a lignin cake.

The wood-based biomass of the present invention may be rice straw, anchovy, by-product of sugarcane, by-product of corn, switchgrass, poplar, oil palm by-product, coniferous trees such as oak, pine and energy crops.

The water content of the lignin cake of the present invention is 40 to 60% by weight, and the pH is 0.5 to 5, which is acidic.

When lignin cakes are prepared by treating the woody biomass with a base treatment instead of an acid treatment, it is difficult to produce modified lignin by using the lignin cake. In this case, the yield of modified lignin is lowered and the denaturation of lignin does not occur properly.

Also, when the moisture content of the lignin cake is less than 40 wt% or more than 60 wt%, the lignin modification does not occur sufficiently in the production of the modified lignin.

Step of preparing lignin solution

The method for producing modified lignin of the present invention includes a step of mixing a hydrogen peroxide and a lignin cake to prepare a lignin solution. Preferably, the lignin cake and the hydrogen peroxide are mixed with 0.2 to 1.5 g of lignin cake per 10 ml of hydrogen peroxide based on 35 to 36% by weight of hydrogen peroxide. It is also preferable to mix lignin cake with hydrogen peroxide and mix well to prepare lignin solution.

Step of adding iron ions

The method for producing the modified lignin of the present invention includes the step of adding iron ions to the lignin solution. The iron ion may be added in the form of ferrous sulfate, and the lignin cake: ferrous sulfate may be added in a weight ratio of 1: 0.01 to 10.0. Iron ions may also be added in the form of pickling water. The pickling water is water generated after acid treatment of the thin oxide film formed on the iron surface (pickling process) after rolling carbon steel and in the heat treatment step. When pickling water is used, it is possible to recycle the by-product in the iron making process and also to supply a large amount of a solution in which iron ions are uniformly mixed.

Centrifugation and Supernatant Removal step

The method for producing modified lignin of the present invention comprises centrifuging the lignin solution to which the iron ions have been added and removing the supernatant.

Drying step

The method for producing the modified lignin of the present invention includes a step of removing the supernatant and drying the remaining solids. In this case, the drying can be carried out by selecting appropriate methods such as freeze drying, natural drying, hot air drying and the like. At this time, it is preferable that the supernatant is removed and the remaining solids are washed with water such as distilled water and then dried to remove trace amounts of components.

Fertilizer composition

The present invention is directed to a fertilizer composition comprising a modified lignin of the present invention. The fertilizer composition has a germination rate improving ability of a plant, a whitening inhibiting ability of a plant, a salt resistance improving ability of a plant, and a growth promoting ability. The plant is not particularly limited and can be most dicotyledonous plants including pepper, lettuce, cabbage, potato and radish, or terminal plants such as rice, barley and the like. In particular, the plant may be a crop cultivated on a reclaimed land or the like that is subject to salt stress. The plant may also be used for producing crops such as cabbage, melon, strawberry, carrot and other vegetable crops such as roses, tulips, grapes and apples such as grains, grasses, grasses, ginsengs, tobacco, rice, barley and other food crops such as alfalfa, Grasses such as grasses and the like.

Advantages and features of the present invention and methods of achieving them will become apparent with reference to the embodiments described in detail below. It should be understood, however, that the invention is not limited to the disclosed embodiments, but is capable of many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, To fully disclose the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims.

&Lt; Materials and methods >

In the present invention, pine trees were used as woody biomass. The MS agar culture broth was prepared by purchasing commercially available MS agar medium. Humic acid was purchased from Sigma Humic acid. Hydrogen peroxide was purchased from Daeshwa Gold Co., Ltd.

&Lt; Example 1 >

<1-1> Production of lignin cake

The woody biomass was added to the Decrystalyzer with 75 wt% sulfuric acid to cause the reaction to liquefy the cellulose and hemicellulose in the biomass and convert the lignin component to a solid phase paste. The paste was poured into a hydrolyzer together with water to adjust the sulfuric acid concentration to 30 wt%. The hydrolyzate was hydrolyzed at 90 ° C for 1 hour to prepare a hydrolyzate. By the hydrolysis, cellulose and hemicellulose were converted into hexose (glucose etc.) and pentose (xylose etc.). The hydrolyzate is fed to the filter press with both the liquid phase and the solid phase (paste) to separate the liquid phase (mixture of sugar and sulfuric acid) and the solid phase (mixture of lignin, unreacted biomass, trace sugar and sulfuric acid) Lignin cake was prepared. The lignin cake was naturally dried and used in powder form.

<1-2> Evaluation of physical properties of lignin cake

The pH of the lignin cake prepared in the above <1-1> was measured and found to be 2.5. It was judged to be due to a trace amount of sulfuric acid remaining in the lignin cake.

On the other hand, about 55% by weight of the lignin cake was confirmed with water.

<1-3> Preparation of modified lignin

1 g of the lignin cake powder prepared in <1-1> was added to 20 ml of hydrogen peroxide (35 to 36% by weight of H 2 O 2) and stirred at 13 rpm at room temperature using a magnetic bar to prepare a lignin solution. On the other hand, 0.1 g, 0.5 g, and 0.7 g of ferrous sulfate (FeSO 4) were added to 10 ml of distilled water, and the lignin solution was added to each of the lignin solutions 5 times at intervals of 10 minutes for 2 hours Lt; / RTI > After centrifugation at 3,000 rpm for 15 minutes, the supernatant was removed, washed twice with distilled water, and lyophilized to prepare modified lignin powder.

&Lt; Experimental Example 2 >

The surface of the Arabidopsis seeds was washed with 30% lactose to remove any impurities attached to the seeds. After washing, cancer treatment was performed at 4 캜 for 24 hours.

On the other hand, the denatured lignin prepared in the above <1-3> was diluted to a concentration of 1,060 mg / L in the MS agar culture, and the seeds were then dotted. And stored in a chamber at 23 [deg.] C for 48 hours, and then germination rate (radicle emergence) was evaluated using a microscope. The germination rate was obtained by repeatedly evaluating three 50 seeds of Arabidopsis thaliana by statistical treatment. After seeding 50 seeds in one dish, they were observed under a microscope after a certain period of time and counted as germination when a radicle was observed in the seeds. The dishes were statistically processed for 3 conditions per condition.

As a comparative example, humic acid and lignin were used instead of the modified lignin, and the other conditions were the same as those of the modified lignin test groups. As a control group, MS medium without any fertilizer sample was used. Three groups per test group were used and 150 seedlings per group were used.

As a result, it was confirmed that the germination rate was improved when the modified lignin was used (Table 1).

MS badge Humic acid Lignin Modified lignin
0.1 g addition group Modified lignin
0.5 g addition group Modified lignin
0.7 g addition group Germination rate (%) 42 48 35 62 59 43

&Lt; Experimental Example 3 > Plant salt resistance test

Arabidopsis seeds were germinated by dotting into MS agar medium for one week. Meanwhile, samples were added to the MS agar medium, namely, humic acid, lignin, and modified lignin prepared in the above <1-3> were diluted to 1,060 mg / L, and then 250 mM NaCl was further diluted . Then, the germinated Arabidopsis thaliana was transferred to the MS agar medium to which the sample and NaCl were added, and cultured for 7 days. The whitening of Arabidopsis leaf was observed. At this time, as the control group, MS medium supplemented with NaCl alone was used without adding any fertilizer sample.

As a result, it was confirmed that the experimental group to which denatured lignin was added inhibited whitening due to NaCl stress (Fig. 2: MS medium, Fig. 3: humic acid, Fig. 4: lignin, Fig. 5: denatured lignin ), Fig. 6: modified lignin (reaction with 0.5 g of FeSO4), Fig. 7: modified lignin (reaction with 0.7 g of FeSO4)).

Claims

Mixing hydrogen peroxide and a lignin cake to prepare a lignin solution;
Adding iron ions to the lignin solution;
Centrifuging the lignin solution to which the iron ions have been added, and removing the supernatant;
Removing the supernatant and drying the remaining solids,
Wherein the lignin cake is prepared by acid hydrolysis of woody biomass.
Method of manufacturing modified lignin.

The method according to claim 1,
Wherein the lignin cake is a solid phase portion obtained by adding water to a paste obtained by acid hydrolysis of woody biomass to hydrolyze and hydrolyzing the mixture to obtain a modified lignin cake.

The method according to claim 1,
Wherein the pH of the lignin cake is 0.5-5.

The method according to claim 1,
Wherein the water content of the lignin cake is 40 to 60 wt%.

The method according to claim 1,
Wherein the iron ions are added in the form of ferrous sulfate.

The method according to claim 1,
Wherein the step of preparing the lignin solution is performed by mixing 0.2 to 1.5 g of lignin cake per 10 ml of hydrogen peroxide.

A fertilizer composition comprising modified lignin prepared by the method of claim 1.

8. The method of claim 7,
Wherein the fertilizer composition has a germination improving ability of the plant.

8. The method of claim 7,
Wherein said fertilizer composition has the ability to inhibit whitening of plants.

8. The method of claim 7,
Wherein the fertilizer composition has a salt resistance-enhancing ability of the plant.