KR101163024B1 - Process for the pre-treatment of waste paper to improve saccharification yield and process for the production of saccharides and bio-ethanol using the same - Google Patents

Abstract

The present invention relates to a hydrolysis pretreatment method of biomass and a sugar compound and bioethanol production method using the biomass treated by the above method, and more particularly, waste paper including waste newspaper or waste paper is used in a regeneration process. Microbial and popping complex pretreatment after physical pretreatment in sea islands, and waste paper hydrolysis pretreatment method which can obtain high saccharification and fermentation efficiency even if waste paper including waste newspaper or waste printing paper is used as biomass. The present invention relates to a method for producing a sugar compound and bioethanol from treated waste paper.

Description

Wastewater hydrolysis pretreatment method for improving glycation yield, sugar compound and bioethanol production process using waste paper treated by the above method {Process for the pre-treatment of waste paper to improve saccharification yield and process for the production of saccharides and bio- ethanol using the same}

The present invention relates to a hydrolysis pretreatment method of biomass and a sugar compound and bioethanol production method using the biomass treated by the above method, and more particularly, waste paper including waste newspaper or waste paper is used in a regeneration process. Wastewater hydrolysis pretreatment method which can obtain high saccharification and fermentation efficiency even if waste paper including waste newspaper or waste paper is used as biomass by physical pretreatment in sea island, followed by microwave and popping complex pretreatment. It relates to a sugar compound and a bioethanol production method using the treated waste paper.

Bioethanol production technology from biomass is commercialized using sugar (sugarcane juice) and starch system (corn and wheat) in Brazil and the United States, and large bioethanol production plants are operating. On the other hand, the bioethanol production process from lignocellulosic biomass, including herbaceous and woody plants including agricultural and forestry wastes, pulp waste, waste paper and various construction wastes as the most abundant substances on earth, has great potential for future bioenergy production. Although the basic process has been revealed through technology development and research in the past decades, commercialization has not been achieved yet due to the limitations of the mass production system application and economic problems.

Unlike other lignocellulosic biomass, waste paper has already undergone mechanical and chemical treatment and does not require strong pretreatment such as acid or alkali treatment. Nevertheless, mild pretreatment processes such as electron beam, carbon dioxide depletion, and manganese for the production of sugars from waste paper have low glycation yield and low economic efficiency, and some cause environmental problems. In order to solve this problem, the optimal pretreatment method is achieved by measuring the enzyme glycosylation rate of the substrate using fiber pretreatment, microwave, popping machine and complex pretreatment method without using any chemical pretreatment method. Gained.

In 2008, Korea produced about 11 million tons of paper and cardboard, and paper consumption accounted for about 9.5 million tons, making the paper industry the world's top 10. In particular, the recycling rate of waste paper is 83%, the highest in the world at 8 million tons per year. In Korea, where pulp production is basically weak, such waste paper recycling is not only eco-friendly in terms of biomass recycling, but according to the "Analysis of Greenhouse Gas Emissions Reduction from Waste Paper Recycling", the reduction of 1.07 tons of carbon dioxide when recycling 1 tonne of waste paper is recycled. It is known to be effective, and waste paper recycling has the function of replacing pulp, reducing greenhouse gas emissions and protecting forests as a carbon sink.

The biofuel production process consists of raw material collection, pretreatment, saccharification, fermentation, and purification. Newspaper of the waste paper mainly uses coniferous pulp, so the lignin content is high and the tissue is dense, so that the enzyme hydrolysis is not easy. And since waste paper has already been removed by lignin and some hemicellulose through mechanical and chemical treatment, it is not easy to increase the enzyme glycosylation rate by the same method as the conventional lignocellulosic pretreatment. In addition, in addition to the ink component of 2% or less of the total weight of paper in waste paper or printing paper, the filler added to increase the printability of newspapers and printing papers is hydrophobic, which causes the enzyme accessibility to hydrophilic cellulose. Therefore, in order to increase the saccharification efficiency and fermentation yield for the production of bioethanol from such waste paper, it is necessary to remove the deinking (ink removal process) and the filler. Conventional deinking and filler removal processes have been carried out under alkaline conditions, in which the fibers have swelling and hydrophilic interfacial properties. However, this treatment method uses a lot of process water in the process of floating flotation and washing, floating and discharging components other than ink components, resulting in poor saccharification and fermentation yields, and causing secondary environmental pollution through recycling processes. Have.

Therefore, in order to efficiently produce bioethanol from waste paper, especially waste paper, ink and fillers in waste papers that act as inhibitors of saccharification and fermentation are removed, and the secondary environmental problems of ink and fillers are not removed. There is a need for the development of pretreatment methods to reduce energy consumption.

The present inventors have completed the present invention by developing a bioethanol production process from waste paper as a result of trying to solve all the disadvantages and problems of the prior art as described above.

Accordingly, an object of the present invention is a hydrolysis pretreatment that can effectively hydrolyze waste paper so as to maximize the saccharification efficiency and yield of bioethanol even when using waste paper including waste newspaper and / or waste print paper as biomass. The present invention provides a method for producing a sugar compound and bioethanol using the pretreated waste paper.

Another object of the present invention is not to use any chemicals in the pretreatment process does not cause environmental problems, waste paper hydrolysis pretreatment method that can reduce the energy consumption in the pretreatment process, sugar compounds using the pretreatment waste paper And it provides a method for producing bioethanol.

Still another object of the present invention is to reduce the process time required to produce bioethanol through a simple and simple process, and to secure industrialization through waste paper hydrolysis pretreatment method, manufacturing a sugar compound and bioethanol using the pretreated waste paper. To provide a way.

Another object of the present invention is to remove the ink and fillers of waste newspapers and / or waste printing papers without using any chemicals, and not to cause environmental problems, and also to cause secondary environmental problems due to the removal of ink and fillers. The present invention provides a waste paper hydrolysis pretreatment method that can easily hydrolyze a paper fingerprint and / or waste print paper, a sugar compound and a bioethanol using the pretreated waste paper.

The objects of the present invention are not limited to the above-mentioned objects, and other objects not mentioned can be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, the present invention comprises a sea island step of treating waste paper with sea island; A microwave processing step of treating the de-sealed waste paper with a microwave; A dehydration step of dewatering the microwave-treated waste paper; And a popping step of popping the dehydrated waste paper.

In a preferred embodiment, the microwave treatment step is carried out by microwave treatment to 300W to 800W for 5 to 20 minutes the de-sealed waste paper.

In a preferred embodiment, the microwave treatment step is performed in a state immersed in 300 to 1000 parts by weight of water per 100 parts by weight of the de-sealed waste paper.

In a preferred embodiment, the popping step is performed by treating under a pressure of 5-20 kg.f / cm 2 in a popping machine.

The present invention also provides a method for producing a sugar compound using waste paper comprising a saccharification step of saccharifying waste paper obtained by the hydrolysis pretreatment method of any one of claims 1 to 4.

In a preferred embodiment, the saccharification step is performed by treating 1 to 20 parts by weight of glycosylase per 100 parts by weight of the waste paper.

In a preferred embodiment, the glycosylase is any one selected from the group consisting of cellulase, xylanase and mixtures thereof.

In addition, the present invention is a pre-treatment step of treating waste paper by the hydrolysis pre-treatment method of any one of claims 1 to 4; A saccharification step of saccharifying waste paper obtained in the pretreatment step; And it provides a bioethanol manufacturing method using waste paper comprising a fermentation step of fermenting the sugar compound obtained in the saccharification step.

In a preferred embodiment, the saccharification step and the fermentation step are carried out simultaneously in a single reactor.

In a preferred embodiment, Klebsiella oxytoca P2, Brettanomyces curstersii, Saccharomyces uvzrun for simultaneous execution of the saccharification step and the fermentation step The recombinant strain of any one of Candida brassicae is processed.

The present invention has the following excellent effects.

First, according to the present invention, even if waste paper including waste newspaper and / or waste printing paper is used as biomass, glycosylation efficiency can be effectively increased without using chemical pretreatment.

In addition, the present invention can improve the saccharification efficiency by 60% or more in the saccharification process without causing any environmental problems because no chemicals are used.

In addition, according to the present invention, it is possible to industrialize the production of bioethanol using waste paper by increasing the economic effect for producing bioethanol through a simple and simple process.

According to the present invention, a sugar compound and bioethanol can be prepared from waste paper having a particularly high lignin content in waste paper.

In addition, according to the present invention it is possible to minimize the production of saccharification and fermentation inhibitors to increase the saccharification efficiency and improve the fermentation yield.

1 is a schematic diagram showing a process for biologically converting the hydrolyzed pretreatment method of the present invention and the waste paper subjected to the pretreatment method into bioethanol.
FIG. 2 is a bar graph showing changes in enzyme hydrolysis of waste paper subjected to the pretreatment method according to an embodiment of the present invention and waste paper to which the pretreatment method according to the comparative example was performed.
3 is a bar graph showing the conversion rate of glucose from cellulose when enzymatic hydrolysis of the waste paper subjected to the hydrolysis pretreatment method according to the embodiment of the present invention and the waste paper subjected to the pretreatment method according to the comparative example,
Figure 4 is a graph of the HPLC analysis results of analyzing the monosaccharides produced according to the hydrolysis enzyme used when saccharifying the waste paper subjected to the hydrolysis pretreatment method according to an embodiment of the present invention.

Although the terms used in the present invention have been selected as general terms that are widely used at present, there are some terms selected arbitrarily by the applicant in a specific case. In this case, the meaning described or used in the detailed description part of the invention The meaning must be grasped.

Hereinafter, with reference to the accompanying drawings and preferred embodiments will be described in more detail the technical configuration of the present invention, which is intended to help the understanding of the present invention is not intended to limit the scope of the invention in any way. That is, the present invention is not limited to the embodiments described herein but may be embodied in other forms. Like reference numerals used to describe the present invention throughout the specification denote like elements.

The technical feature of the present invention is to effectively replace the chemical deinking process and the filler removal process for removing the ink and fillers that act as a blocker in the enzymatic saccharification process while contained in a large amount of waste paper including waste newspaper and / or waste printing paper. In the waste paper hydrolysis pretreatment method which can produce high yields of sugar compounds and bioethanol even if waste paper including waste newspaper and / or waste printing paper is used as biomass.

Therefore, the waste paper hydrolysis pretreatment method of the present invention comprises a sea island step of treating waste paper with a sea island; A microwave processing step of treating the de-sealed waste paper with a microwave; A dehydration step of dewatering the microwave-treated waste paper; And a popping step of popping the dehydrated waste paper.

As described above, the present invention can remarkably increase the hydrolysis efficiency of waste paper through a composite pretreatment process in which the waste paper is dissociated with a sea island and dissociated, treated with microwaves, and then popped through a dehydration process.

Here, the sea island step may be performed very easily because the waste paper is put into the sea island of a known configuration. In addition, the microwave treatment step is preferably carried out by microwave treatment at 300W to 800W for 5 to 20 minutes by immersion in 300 to 1000 parts by weight of water per 100 parts by weight of de-sealed waste paper. The dehydration step is preferably carried out to have a moisture content of 60-80% of the microwave-treated waste paper, and the popping step is preferably performed under a pressure of 5 to 20 kg · f / cm 2, especially 15 to 20 kg · f / cm 2. Do.

In addition, the saccharification process of the pretreated biomass may be carried out by acid saccharification according to a conventional method, but in the present invention, the enzyme saccharification (enzymatic) by a method in which no chemical substance such as an acid is added at all. more preferably by saccharification). For enzyme saccharification, preference is given to using glycosylase selected from the group consisting of, for example, cellulase, xylanase and mixtures thereof. Representatively, it may be preferable to use a mixed enzyme of cellulase and xylanase in a weight ratio of 1 to 2: 1 to 2, especially 2: 1. The glycosylase is preferably used in an amount of 1 to 20 parts by weight based on 100 parts by weight of the biomass. In addition, the saccharification process is preferably performed for 6 to 24 hours, particularly for 24 hours at a temperature of 40 ~ 45 ℃.

In addition, in the present invention, as a fermentation strain for the production of bioethanol, yeast, for example, Saccharomyces cerevisiae ( Saccharomyces cerevisiae ) can be used, and sugar-resistant strains and enzymes capable of fermentation at high sugar concentrations. Heat resistant strain capable of converting ethanol even near the optimum temperature of glycosylation, recombinant strains capable of simultaneously glycosylation and fermentation to reduce the use of expensive enzymes and produce high concentrations of ethanol, for example, Krebsiella oxy Klebsiella oxytoca P2, Brettanomyces curstersii, Saccharomyces uvzrun , Candida brassicae , etc. Can also be used. When the fermentation process is performed separately from the saccharification process, it is preferable to carry out for 12 to 24 hours at a temperature of 25 to 30 ° C., particularly 30 ° C., but it may be performed simultaneously with the saccharification process.

Example 1

After dissociating the waste paper (Jeonnam University Press) into a sea island of known configuration, microwave treatment and popping pretreatment were performed as follows. First, microwave treatment was performed by immersing the waste island waste paper sample in water in the microwave oven so that the weight ratio of the island fish waste paper sample and water was 1: 6, and then treated at 750w for 15 minutes. After dehydration at 75% water content using a dehydrator of a known configuration, the waste newspaper sample having a water content of 75% was placed in a popping machine having a conventionally known structure and subjected to 200 ° C., 20 kg · f / cm 3. A popping pretreatment was performed under pressure to prepare a waste paper indicator (MI + Pop).

Comparative Example 1

A sample (WT) that had not been pretreated at all with the same waste newspaper as used in Example 1 was used as a control.

Comparative Example 2

A waste newspaper sample (MI) was prepared by performing only the myrowave pretreatment method described in Example 1, the same waste newspaper as used in Comparative Example 1.

Comparative Example 3

A waste newspaper sample (Pop) was prepared by performing only the popping pretreatment method described in Example 1, the same waste newspaper used in Comparative Example 1.

Experimental Example 1

The chemical components of the waste newspaper sample (MI + Pop) obtained in Example 1 and the waste newspaper sample (WT), waste newspaper sample (MI), and waste newspaper sample (Pop) obtained in Comparative Example 1-3 were tested. The results are shown in Table 1.

% WT (Control) MI Pop MI + Pop  Organic Solvent Extract 0.4 0.3 0.2 0.2  Holocellulose 73.6 74.1 75.3 75.8  Lignin 19.6 19.2 18.6 18.7  Ash 5.0 5.1 4.3 4.1

From Table 1, the holocellulose content of the microwave pretreatment (MI), popping pretreatment (Pop), microwave + popping composite pretreatment (MI + Pop) compared to the control (WT) not subjected to hydrolysis pretreatment at all Tended to increase slightly, while the content of lignin and ash decreased slightly. These results indicate that some of the ink or filler was removed by each pretreatment, which also affects the future glycation rate.

Experimental Example 2

The monosaccharide changes of the waste newspaper sample (MI + Pop) obtained in Example 1 and the waste newspaper sample (WT), waste newspaper sample (MI), and waste newspaper sample (Pop) obtained in Comparative Example 1-3 were analyzed. The results are shown in Table 2 below.

% arabinose xylose mannose glucose galactose  Control 0.5 8.5 5.2 52.9 1.3  Microwave 0.2 9.2 3.1 55.8 0.4  Popping 0.1 8.9 3.3 57.1 0.2  Mi + Popping 0.1 8.8 2.8 57.7 0.3

As a result, the increase in glucose showed the same pattern as the increase in the amount of holocellulose shown in Table 1, and the reduction of sugars other than cellulose and xylose, which are relatively stable structures, and the reduction of inorganic components such as inks and fillers mentioned above. It can be seen from Table 2 that appeared to be caused by.

According to these experimental results, the complex pretreatment method of the present invention can be predicted to cause physical and structural changes in addition to chemical composition changes.

Example 2

To 50 mg of waste newspaper indicator (MI + Pop) obtained in Example 1 was added by mixing the cellulase 600U / sub.g and xylase 300U / sub.g, performing a saccharification process for 96 hours at a temperature of 37 ℃ A sugar compound (MI + Pop) was obtained.

Comparative Example 4

A sugar compound (WT) was obtained in the same manner as in Example 2 except that the waste newspaper indicator (WT) obtained in Comparative Example 1 was used.

Comparative Example 5

A sugar compound (MI) was obtained in the same manner as in Example 2 except that the waste newspaper indicator (MI) obtained in Comparative Example 2 was used.

Comparative Example 6

A sugar compound (Pop) was obtained in the same manner as in Example 2 except that the waste newspaper indicator (Pop) obtained in Comparative Example 3 was used.

Experimental Example 3

In order to compare the enzyme saccharification efficiency according to the pretreatment process, the reducing sugars obtained in Example 2 and Comparative Examples 3 to 6 were measured using the DNS method, and the measurement results are shown in FIG. 2. In addition, the monosaccharide analysis was performed on the reducing sugars obtained in Example 2 and Comparative Examples 3 to 6 using HPLC, and the conversion rate from cellulose to glucose after enzymatic saccharification of the waste paper according to Comparative Examples and Examples is shown in FIG. 3. Indicated.

Referring to Figure 2, after the enzyme glycation control (sugar compound (WT)) 4.3 mg / ㎖, microwave pretreatment [sugar compound (MI)] 4.9 mg / ㎖, popping pretreatment [sugar compound (Pop)] Is 5.4 mg / ml, after microwave treatment popping composite pretreatment [sugar compound (MI + Pop)] showed a sugar content of 6.9 mg / ml, control, microwave pretreatment, popping pretreatment, microwave + popping pretreatment The sugar content increased in order.

The above experimental results showed that the glycosylated compound (MI + Pop) obtained by enzymatic saccharification after the microwave + popping composite pretreatment method of the hydrolysis pretreatment method of the present invention was subjected to the control, microwave pretreatment, and popping pretreatment method. 60%, 41%, and 28% increase compared to the sugar compounds (WT), (MI), and (Pop) obtained.

In addition, referring to Figure 3, after the pretreatment according to the Comparative Examples and Experimental Examples, the enzyme saccharification efficiency of the cellulose contained in the waste paper was examined, the glycosylation rate was 58% in the control, microwave pretreatment [sugar compound (MI) ] Was 65%, popping pretreatment [sugar compound (Pop)] 72%, microwave treatment after popping composite pretreatment [sugar compound (MI + Pop)] showed 90%. In particular, the popping composite pretreatment after microwave treatment showed a 55% improvement over the glycation rate of the control.

Experimental Example 4

A mixture of two enzymes, a sugar compound (C) obtained by treating the waste newspaper indicator (MI + Pop) of Example 1, a sugar compound (X) obtained by treating xylase, and a cellulase and xylase as in Example 2 Monosaccharide analysis was performed on the sugar compound (CX) obtained by treatment using HPLC. The analysis results are shown in FIG. 4.

As shown in FIG. 4, when comparing the sugar compounds obtained by treating the pulmonary newspaper sample (MI + Pop) of Example 1 with a cellulase, xylase, and a mixture of cellulase and xylase, respectively, in the sugar compound (CX) It can be seen that the glucose peak is much higher than other sugar compounds (C) and (X), and the sugars in the enzyme hydrolyzate are mostly composed of glucose.

These experimental results show that the sample treated by the pretreatment method of the present invention may be suitable for biotechnological processes using enzymes by thermal and physical treatment without any chemical treatment.

Example 5

Bioethanol production

1. Hydrolysis Pretreatment Process

The same procedure as in Example 1 was carried out to obtain a waste newspaper sample (MI + Pop).

2. Saccharification Process

The same process as in Example 2 was performed to obtain a sugar compound (MI + Pop), that is, glucose.

3. Fermentation process

The resulting glucose concentration was concentrated to 10%, 15 g / l was added to Saccharomyces cerevisiae as a fermentation strain for bioethanol production, and bioethanol was produced by performing a fermentation process at a temperature of 30 ° C. for 24 hours. .

At this time, the saccharification process and the fermentation process may be performed at the same time.

On the other hand, although the waste paper was used in the above-described embodiment, it was found that even if the hydrolysis pretreatment method of the present invention was applied to all waste paper including waste printing paper and waste cardboard, the same effect was obtained.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, Various changes and modifications will be possible.

Claims (10)

A sea island step of treating waste paper with a sea island;
A microwave processing step of treating the de-sealed waste paper with a microwave;
A dehydration step of dewatering the microwave-treated waste paper; And
Waste paper hydrolysis pretreatment method comprising a popping step of popping the dehydrated waste paper.
The method of claim 1,
The microwave treatment step is a waste paper hydrolysis pre-treatment method, characterized in that is carried out by microwave treatment to 300W to 800W for 5 to 20 minutes the de-sealed waste paper.
The method of claim 2,
The microwave treatment step is a waste paper hydrolysis pre-treatment method, characterized in that carried out in a state immersed in 300 to 1000 parts by weight of water per 100 parts by weight of the de-sealed waste paper.
The method of claim 1,
The popping step is a waste paper hydrolysis pre-treatment method characterized in that the treatment under a pressure of 5 ~ 20 kg · f / ㎠ in a popping machine.
A method for producing a sugar compound using waste paper comprising a saccharification step of saccharifying waste paper obtained by the hydrolysis pretreatment method according to any one of claims 1 to 4.
The method of claim 5, wherein
The glycosylation step is a sugar compound manufacturing method using waste paper, characterized in that the waste paper is processed by processing 1 to 20 parts by weight of glycosylase.
The method according to claim 6,
The glycosylase is a method of producing a sugar compound using waste paper, characterized in that any one selected from the group consisting of cellulase, xylanase and mixtures thereof.
A pretreatment step of treating waste paper by the hydrolysis pretreatment method of any one of claims 1 to 4;
A saccharification step of saccharifying waste paper obtained in the pretreatment step; And
Bioethanol production method using waste paper comprising a fermentation step of fermenting the sugar compound obtained in the saccharification step.
The method of claim 8,
The method for producing bioethanol using waste paper, characterized in that the saccharification step and the fermentation step is carried out simultaneously in a single reactor.
The method of claim 9,
Klebsiella oxytoca P2, Brettanomyces curstersii, Saccharomyces uvzrun , Candida brascaier Candida brassicae bioethanol production method using waste paper, characterized in that any one of the recombinant strains is processed.

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