KR20170126291A - Method of Preparing Saccharification Liquid from Biomass - Google Patents

Abstract

The present invention relates to a method for producing a saccharification solution from biomass. More specifically, the present invention relates to a method for producing a saccharification solution from biomass, which does not require additional supply of acid by re-circulating acetic acid generated during a biomass pre-treatment process. In addition, the method also prevents corrosion on devices due to strong acid and also improves performance of saccharification and fermentation by removing, at a front end, acetic acid which inhibits rear end saccharification and fermentation.

Description

[0001] The present invention relates to a method for preparing a saccharified liquid from biomass,

The present invention relates to a method for producing a saccharified liquid from a biomass, and more particularly, to a method for producing a saccharified liquid from a biomass, characterized by recovering and reusing acetic acid generated in a biomass pretreatment process.

Fiber-based biomass has advantages such as abundant amount, excellent regeneration characteristics and low cost of raw materials, and thus it is increasingly used as an alcohol raw material for fuels such as ethanol and butanol. Fiber-based biomass is strongly bound to main components such as cellulose, hemicellulose, and lignin. Therefore, it is necessary to separate these three components from each other through pretreatment in order to produce a glycated liquid at a high yield from biomass.

Among them, cellulose is thermally stable, has a characteristic of dissolving in acid, hemicellulose is unstable in heat and soluble in acid. On the other hand, lignin is stable to heat and soluble in alkali.

Various pretreatment processes have been developed to efficiently separate each component having different characteristics. Among the processes developed in the past, the most ideal pretreatment method is to selectively remove the lignin component without loss of the cellulose component (converting the fibrinogen raw material into an easy form for glycosylation by the enzyme).

Major pretreatment methods include mechanical pulverization, alkali swelling, dilute acid hydrolysis, hydrothermal pretreatment, and steam explosion pretreatment.

Among these, hydrothermal treatment can separate hemicellulose into liquid phase by water under mild condition, where cellulose and lignin remain in the solid phase. It is a method for increasing the recovery rate of hemicellulose having low thermal stability by using mild conditions.

In addition, the pretreatment of steam explosion can obtain the ruptured raw material by pressurizing the raw material in the pressurized reactor and blowing saturated steam, and then suddenly releasing the pressure. In this process, hydrolysis of hemicellulose occurs or the structure of lignin is destroyed. It is not necessary to pulverize the raw material, and it has high energy efficiency.

Among the various pre-treatment methods, the selection of efficient pretreatment methods should be considered along with the increase of the yield per day. In the case of the acid treatment method, the pretreatment efficiency can be improved by increasing the pretreatment severity, but it may be difficult to apply the commercialization process due to the corrosion problem of the equipment. Also, if the acid is used continuously, OPEX (Operating Expenditure) will increase, which can also cause a rise in manufacturing cost.

US Patent Publication No. 2014-0154759 discloses a method for producing low ash biomass for biomass or pellets for combustion. Here, the method of treating the biomass with acetic acid, separating the liquid phase into the solid phase portion, extracting the low batch biomass from the solid phase portion, and removing the liquid phase portion with the acetic acid by evaporation, Which is expensive to separate acetic acid and has a disadvantage in that the production efficiency of the saccharified liquid is lowered because the solid part is used for the production of fuel for combustion.

U.S. Patent Publication No. 2015-0051385 discloses a liquid / liquid separation method of lignocellulose for producing saccharified liquid. Here, the biomass is pretreated with heated acetic acid. A method of separating a liquid phase portion containing lignin from a solid phase portion containing cellulose and recycling the acetic acid in the liquid phase portion has been described. However, the use of heated acetic acid is costly to maintain a high temperature, The distillation is used as a method, so the overall operation cost is high.

As a result of intensive efforts to solve the above problems, the present inventors have found that, as a result, the xylose-oligomer-containing fraction, the cellulose and the lignin-containing fraction produced in the biomass are separated and saccharified and then the acetic acid of the xylo-oligomer- And adsorption, recycled by the pretreatment process of the biomass, and a part of the recycled acetic acid is introduced into the step of saccharification. As a result, the pretreatment efficiency can be increased without supplying acid, corrosion of the device by strong acid is prevented, It has been confirmed that the saccharification efficiency is increased by performing the saccharification step by separating the acetic acid which inhibits the latter-stage saccharification or the fermentation reaction, thereby completing the present invention.

It is an object of the present invention to provide a method for recycling acetic acid produced in the biomass pretreatment / saccharification process to reduce the operation cost and improve the efficiency of saccharified liquid production from biomass.

In order to accomplish the above object, the present invention provides a method for producing a biodegradable polymer, comprising the steps of: (a) preliminarily treating biomass and then separating into xylo-oligomer-containing fractions and cellulose and lignin-containing fractions; (b) secondary pretreatment of the cellulose and the lignin-containing fraction, followed by saccharification using an enzyme, followed by obtaining a hexose sugar; And (c) subjecting the xylose-oligomer-containing fraction to filtration and adsorbent resin to remove substances inhibited by the saccharification and fermentation process, removing a considerable amount of water by concentration and then saccharifying, And recovering the acetic acid produced in the step (c) of the step (c) by the desolvation process, and the step (b) is carried out in the primary pretreatment step And recycling the biomass to the biomass.

The method for producing the saccharified liquid from the biomass according to the present invention is characterized in that acetic acid which does not require additional acid supply when biomass pretreatment and PTL (pretreated liquid) saccharification are recycled and saccharification or fermentation reaction is inhibited The saccharification efficiency and the fermentation efficiency are increased by performing the saccharification and fermentation process, so that it is useful for the production of an efficient saccharification liquid.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a flow diagram of a method for preparing a saccharified liquid from a biomass according to an embodiment of the present invention.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In general, the nomenclature used herein is well known and commonly used in the art.

In the embodiment of the present invention, the biomass is pretreated, and then the xylose-oligomer-containing fraction, the cellulose and the lignin-containing fraction are separated, and the glycation reaction is carried out. The glycated solution of the xylose- ) And adsorbent resin were used to remove fermentation inhibitors such as fine and inorganic substances, and a considerable amount of water was removed through a concentration process, followed by saccharification through a saccharification process. Acetic acid was then separated through adsorption and desorption processes and recycled to the biomass pretreatment process. As a result, high saccharification efficiency was achieved without addition of acid, and saccharification efficiency was increased by separating acetic acid which inhibits downstream saccharification or fermentation reaction and performing saccharification process.

Accordingly, the present invention provides a method for producing a biodegradable biodegradable biodegradable biodegradable pharmaceutical composition comprising the steps of: (a) first pretreatment a biomass and then separating the biodegradable biodegradable polymer into a xylo-oligomer-containing fraction and a cellulose and lignin-containing fraction; (b) secondary pretreatment of the cellulose and the lignin-containing fraction, followed by saccharification using an enzyme, followed by obtaining a hexose sugar; And (c) removing fine particles by using filtration and adsorbent resin, removing fermentation inhibiting substances such as minerals or cations, removing a considerable amount of water through a concentration process and then saccharifying, and then adsorbing for the recovery of acetic acid (AA) And recovering the acetic acid produced in the step (c) of the first pre-treatment and / or the step (c) of the step (c) in the desorption step, And a method for producing a saccharified liquid from a biomass, characterized in that the saccharification is recycled to the former stage of the PTL stage saccharification process.

A general schematic diagram of a process for producing a saccharified liquid from a biomass according to the present invention is shown in Fig.

1. Pre-treatment of biomass and solid-liquid separation process (step (a))

The first step in the method of producing the saccharified liquid according to the present invention is a method in which biomass is subjected to a first pretreatment (FIG. 1, pretreatment A), a fraction containing a xylo-oligomer (PTL, Pretreated Liquid) and a cellulose And fraction containing lignin (PTB, Pretreated Biomass).

2. Saccharification process

2-1. The saccharification step of PTB (step (b))

In the saccharification process according to the present invention, the first step in the saccharification step is a step of pre-treating the cellulose and the lignin-containing fraction (PTB) separated in the step (a) To obtain C6 enriched-sugar.

2-2. The saccharification step of PTL (step (c))

In the saccharification solution according to the present invention, the second step of the saccharification step is a step of filtering the xylo-oligomer-containing fraction (PTL) separated in the step (a), removing fine particles using the adsorption resin, HMF, and furfural. After removing a considerable amount of water by concentration, monosaccharides are formed by physical / chemical method. After the adsorption process and desorption process for AA recovery, high purity 5-sugar is converted into high purity Gt; C5 < / RTI > enriched-sugar.

Since PTL contains a large amount of microbial fermentation inhibiting components (acetic acid, HMF, Furfural), it is necessary to concentrate and adsorb it to remove it.

The recovered acetic acid can be introduced into the pretreatment process (low concentration acetic acid made by concentration and high concentration acetic acid separated by adsorption) to improve the pretreatment efficiency.

A part of acetic acid derived from biomass which is continuously produced in a pretreatment process, which is not a strong acid such as sulfuric acid, hydrochloric acid, or phosphoric acid, which is widely used in conventional pretreatment, is reused. It is an economical and efficient pretreatment method that increases the pretreatment effect by increasing the severity (hydrothermal treatment, temperature, time, pH) of acetic acid from the acetyl group in hemicellulose, which is a component of some reusable biomass.

The method for producing a saccharified liquid according to the present invention may further include the step of supplying the separated condensed water in the concentration step of step (c) to a desorption process for use as desorption water in the acetic acid adsorption / desorption process .

As shown in FIG. 1, when the concentration step is performed after the adsorption step for filtration and impurity removal in step (c), the amount of heat required for heating in the saccharification step can be reduced, By reducing throughput, CAPEX (Capital Expenditure) can be reduced. Also, the condensed water generated in the concentration process can be supplied to the desorption process, and can be used as desorption water by heating, but the present invention is not limited thereto. At this time, the concentration of acetic acid separated in the desorption process is preferably 5 to 30w%.

In the concentration step, acetic acid and water are evaporated together and separated. Therefore, acetic acid separated in the concentration step is diluted with water to have a relatively low concentration. In the desorption process, acetic acid and impurities are adsorbed independently of water, A high concentration of acetic acid is separated.

In the present invention, a part of the recycled acetic acid may be introduced into the step (c) in the step (c). In the PTL treatment process, oligomers are converted to pentoses through monomerization. In this case, when the acid is fed to the saccharification reaction, the conversion rate is increased. Therefore, as shown in FIG. 1, a part of the acetic acid recovered in the desorption process can be introduced into the saccharification step to increase the conversion rate of the saccharification reaction. The amount of acetic acid recovered and reused varies depending on the acetyl content of biomass. However, when 49 dry ton / day of biomass is treated, the amount of acetic acid generated is 0.17-1.67 ton / day, and acetic acid recycled in the pre- The weight ratio of the discharged acetic acid (ⓒ in FIG. 1) is 90:10 to 98: 2, and the corresponding concentration is 5 to 30%. In the case of low concentration of AA, it is possible to inhibit the inhibitor formation at low pH by increasing the severity by the reaction temperature and reaction time, and when the high concentration AA is applied, the reaction temperature and reaction time are controlled By lowering the severity, it is possible to produce efficiently by reducing the amount of steam used and increasing the productivity. For the recovered AA, the PTL singaltylation efficiency can be raised by introducing a part of the recovered AA into the PTL single saccharification shear (b in Fig. 1). At this time, it is preferable that the weight of AA injected is such that the AA concentration of the PTL singulated shear stream is 30 to 50%.

In addition, all of the recovered acetic acid can be recycled and used in the pretreatment process, and when the concentration of acetic acid in the interior is increased, side reactions may occur, some or all of the recovered acetic acid may be discharged to the outside. However, the total amount of acetic acid recycled in the pretreatment A step, acetic acid fed into the singly saccharification step, and acetic acid discharged to the outside should be the same as the amount of acetic acid recovered in the AA adsorption process. This prevents the accumulation of acetic acid inside, .

In the present invention, the concentration in the step (c) may be characterized by vacuum concentration. The concentration process is a process for evaporating an object using heat. Accordingly, it is preferable to lower the boiling point of the object because the lower the boiling point of the object is, the lower the boiling point of the object is possible. Therefore, the concentration process is preferably performed in a vacuum to minimize the amount of heat consumed, and more preferably, it can be performed at a pressure of 10 to 300 torr.

In the present invention, the secondary adsorption in the step (c) may be characterized by using activated carbon as an adsorbent. In the secondary adsorption process of the present invention, any adsorbent capable of adsorbing acetic acid can be used without limitation, but an adsorbent capable of adsorbing acetic acid can be used without limitation, but an ion exchange resin such as activated carbon, zeolite, silica gel, aluminum sulfate, Is preferably used.

[Example]

Hereinafter, the present invention will be described in more detail with reference to Examples. It is to be understood by those skilled in the art that these embodiments are only for illustrating the present invention and that the scope of the present invention is not construed as being limited by these embodiments.

Example  1: Through recycling of acetic acid From biomass Glycated liquid  production

As shown in Fig. 1, the biomass was subjected to a primary hydrothermal treatment at a temperature of 185 캜 for 5 minutes, and then subjected to solid-liquid separation into cellulose, lignin-containing fraction and xylo-oligomer-containing fraction. The fraction containing cellulose and lignin was subjected to a saccharification reaction after the second pretreatment through mechanical treatment to produce hexose. The xylose-oligomer-containing fraction was subjected to filtration and adsorption resin to remove fine particles and cation , And then a significant amount of water was removed through a concentration process and a saccharification process was performed. After the saccharification process, acetic acid (AA) was separated and recovered through adsorption and desorption process using activated carbon. At this time, the condensed water obtained in the concentration process was used as desorption water. The remaining high concentration (70 wt%) of acetic acid was recovered and then recycled by the first pre-treatment process, and some of the recycled acetic acid was added to the saccharification step Respectively.

The recovery and reuse amount of acetic acid depends on the acetyl content of biomass, but the amount of acetic acid produced when 49 dry ton / day of biomass is treated is 0.276 ton / hr, and the recycled amount of acetic acid adsorbed in the adsorption process (ⓐ + ⓑ ) And the amount released to the outside (ⓒ) is 90:10 ~ 98: 2, corresponding to 5 ~ 30%. In the case of low concentration AA, it is possible to inhibit the inhibitor formation at low pH by increasing the severity by the reaction temperature and reaction time, and when the high concentration of acetic acid (AA) is applied, By adjusting the time to lower the severity, it is possible to efficiently produce by reducing the amount of steam used and increasing the productivity. For the recovered AA, a part of the AA was added to the PTL single saccharification shear stage to increase the PTL single saccharification efficiency, and the weight of the loaded AA was controlled to be 30 to 50% by weight of the AA concentration of the PTL single saccharified shear stream .

According to the embodiment of the present invention, acetic acid generated in the pretreatment process is recovered and concentrated and added to the pretreatment process, thereby increasing the degree of severity and enhancing the pretreatment effect. By using acetic acid generated in the pretreatment process, there is no increase in OPEX because no additional chemical cost is incurred. By using weak acid which is not a strong acid, there is no erosion of the apparatus, so the investment cost is reduced when the plant is built. In addition, saccharification / fermentation performance is enhanced by removing acetic acid acting as an inhibitor in the downstream saccharification and fermentation process at the front end, and other impurities such as prophrore and HMF can be recovered in the process of recovery of acetic acid, .

While the present invention has been particularly shown and described with reference to specific embodiments thereof, those skilled in the art will appreciate that such specific embodiments are merely preferred embodiments and that the scope of the present invention is not limited thereto will be. Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

Ⓐ: Acetic acid recycled by the biomass pretreatment process
Ⓑ: Acetic acid to be recycled and the acetic acid
Ⓒ: Externally released acetic acid, fluffral and HMF

Claims (8)

(a) subjecting the biomass to a first pretreatment and then separating into a fraction containing xylo-oligomer and a fraction containing cellulose and lignin;
(b) secondary pretreatment of the cellulose and the lignin-containing fraction, followed by saccharification using an enzyme, followed by obtaining a hexose sugar; And
(c) fractionating the xylose-oligomer-containing fraction by filtration and adsorbing resin to remove substances inhibited by the saccharification and fermentation process, removing a considerable amount of water by concentration and then saccharifying, and thereafter carrying out an acetic acid adsorption process and a desorption process Lt; RTI ID = 0.0 > 5, < / RTI >
Wherein the acetic acid produced in the first pre-treatment step and / or the step (c) is recovered in the desorption step and recycled to the first pre-treatment step.
The method according to claim 1, further comprising the step of supplying a desorption process for use as a desorption water in an acetic acid desorption / desorption process, wherein the condensed water generated in the step (c) How to.
The method of claim 1, wherein the concentration of acetic acid isolated in the desorption process is 5 to 30 wt%.
The method for producing a saccharified liquid from a biomass according to claim 1, wherein part of the recycled acetic acid is introduced into the step (c).
The method of claim 4, wherein the weight ratio of acetic acid recycled to the pre-treatment step and acetic acid discharged is 90:10 to 98: 2, and acetic acid is added so that the acetic acid concentration of the saccharylation shear stream is 30 to 50% Of the biomass.
The method for producing a saccharified liquid according to claim 1, wherein the step (c) is a vacuum concentration step.
7. The method of claim 6, wherein the vacuum concentration is performed at a pressure of 10 to 300 torr.
The method according to claim 1, wherein the second adsorption step in step (c) is used as an adsorbent selected from the group consisting of activated carbon, zeolite, silica gel, aluminum sulfate and cation exchange resin. .

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