KR20090039470A - Saccharification of woody biomasses using supercritical water in presence of acid catalysts - Google Patents

Abstract

A saccharizing method of wood type bio-mass using acid-catalase and supercritical water is provided to obtain monosaccharide which is main ingredient of bio-ethanol from wood type bio-mass as well as starch type ingredient and substitute starch type ingredient in a field of producing bio-ethanol ingredient. A monosaccharide is obtained from wood type bio-mass by saccharizing with supercritical water under acid catalysis at 325-425°C, 218.3-340atm for 10-120 seconds. The wood type bio-mass comprises populus, pitch pine, larch, yellow poplar, poplar, or rice straw. The acid catalyst is the hydrochloric acid, the acetic acid, and the nitric acid or the sulfuric acid.

Description

Saccharification of woody biomasses using supercritical water in presence of acid catalysts

The present invention relates to a method of saccharifying wood-based biomass using an acid catalyst and supercritical water, and more particularly, in the saccharification of wood-based biomass, by decomposing the wood-based biomass into supercritical water under an acid catalyst, the monosaccharide from wood-based biomass. It relates to a saccharification method for preparing the.

Bio-mass refers to a biological organism including plants, cells and animals that eat and live by photosynthesis of plants and microorganisms that receive solar energy.

Biomass resources include starch-based resources, including grains and potatoes, cellulose-based resources, including agricultural, aquatic products such as herbs, wood and rice straw, chaff, and sugar-based resources such as sugar cane and sugar beets, as well as livestock manure, carcasses and It has a variety of properties, including protein-based resources, including microbial cells.

Bio-energy using biomass is produced by extracting fats and oils from oil crops and esterifying them to produce biodiesel, and alcohol-fermenting sugars obtained by saccharifying starch crops and / or fibrous plants to produce bioalcohols. For example, there are various fields such as anaerobic fermentation of organic wastes to obtain methane gas and production of methanol therefrom.

In the production of bioalcohol by alcohol-fermenting the sugar obtained by saccharifying the starch crop and / or fibrous plant, the starch crop may be barley, corn, etc., and the fibrous plant may be wood, rice straw, or the like. .

Acid hydrolysis and biological enzyme saccharification are used for the saccharification process of wood-based biomass.

The acid hydrolysis of the wood-based biomass is a process of producing monosaccharides such as glucose, mannose, galactose, xylose, arabinose, and the like by decomposing ether bonds formed between fibers of wood-based biomass using sulfuric acid. In this method, the conversion of woody biomass to monosaccharides is high, but corrosion of process equipment is always a problem because it uses relatively high concentration of sulfuric acid. And since the final product is present under acidic conditions, there is a disadvantage that the neutralization process for ethanol fermentation.

The enzymatic glycosylation method of the wood-based biomass is a starch-based glycosylation process for converting agricultural biomass composed of starch into glucose by amylase / glucoamylase and the like, and decomposing wood-based cellulose by using an enzyme isolated from wood fungus called cellulase. It can be divided into the wood-based saccharification process that produces glucose. At present, starch-based glycosylation process is widely used, but enzymatic saccharification of woody biomass is still in the research stage due to the structural characteristics of woody biomass. Cellulase, an enzyme necessary for the hydrolysis of wood biomass, is still very economical because its price is very expensive and the glycosylation reaction is very long.

Supercritical fluids are fluids that exist in a state beyond the critical temperature and critical pressure that each fluid inherently has. In this state, each fluid exhibits new characteristics unlike the general characteristics exhibited at room temperature / atmospheric pressure.

When the water used in the present invention reaches the supercritical state, the supercritical water disappears the neutral properties of the water and exhibits acid properties, and when the water returns to the room temperature / atmospheric state instead of the supercritical state, the acid has the supercritical state. The characteristic of disappears.

In the present invention, the supercritical water, which is water in a supercritical state, has an acidic characteristic, so that the reaction time of glycosylated biomass can be shortened very shortly by saccharifying wood-based biomass using an acid catalyst and the supercritical water. In addition, since water is used as a decomposition medium, disadvantages such as corrosion of a conventional process facility by sulfuric acid can be solved.

The present invention provides a saccharification method for saccharifying wood-based biomass using an acid catalyst and supercritical water to obtain monosaccharides, a raw material for producing bioethanol, from wood-based biomass.

The present invention focuses on the saccharification reaction of wood-based biomass using acid catalyst and supercritical water instead of sulfuric acid. It is possible to shorten the short, and to provide a saccharification method of wood-based biomass that can solve the disadvantages such as corrosion of the process equipment by the conventional sulfuric acid.

The present invention can provide a saccharification method for producing monosaccharides from woody biomass by degrading woody biomass into supercritical water under acidic catalyst in saccharification of woody biomass.

The present invention is to obtain a monosaccharide from the cellulose component, which is a major component of the wood-based biomass using an acid catalyst and supercritical water. In the future, the monosaccharide, which is the main raw material of bioethanol, can be obtained from wood-based biomass as well as conventional starch-based raw materials. It can be effective.

The present invention can be expected to produce an effect of replacing the conventional starch-based raw materials in the bioethanol raw material production field by producing a monosaccharide from the wood-based biomass.

The present invention shows a method of saccharifying wood-based biomass using an acid catalyst and supercritical water.

In the present invention, the saccharification method of wood-based biomass using an acid catalyst and supercritical water, in the saccharification of wood-based biomass, can decompose the wood-based biomass into supercritical water under an acid catalyst to prepare monosaccharides from the wood-based biomass.

In the present invention, when the wood-based biomass is saccharified using the acid catalyst and the supercritical water, the wood-based biomass is saccharified for 10 seconds to 120 seconds with the supercritical water at a pressure of 218.3 to 340 atm and a temperature of 325 to 425 ° C. under the acid catalyst. Monosaccharides can be prepared from these.

In the present invention, in the reaction between the wood-based biomass and the supercritical water during the saccharification of the wood-based biomass using the acid catalyst and the supercritical water, the acid catalyst is mixed by 5 to 100 times the weight of the wood-based biomass and the wood-based biomass. Monosaccharides can be prepared from woody biomass by glycosylation under

In the present invention, the wood-based biomass may use any one selected from hawthorn, rigi pine, larch, lily, poplar, and straw.

In the present invention, the wood-based biomass may use any one selected from hibiscus, Rigida pine, larch, lily, poplar and rice straw in powder form.

In the present invention, the wood-based biomass may use any one selected from sagewood, rigi pine, larch, lily, poplar, and straw in the form of a slurry.

The wood-based biomass in the present invention, the wood-based biomass in the present invention is any one selected from hawthorn, rigi pine, larch, lily, poplar, rice straw and dried to a moisture content of 10 to 15% and then powdered with a grinder. It can be used in one powder form.

In the present invention, the wood-based biomass is pulverized after drying so that the water content is 10 to 15% selected from thorny bark, rigi pine, larch, lily, poplar, and straw, and passed through 60 mesh (mesh) sieve. Powdered forms can be used.

In the present invention, the wood-based biomass is pulverized after drying so that the water content is 10 to 15% selected from thorny bark, rigi pine, larch, lily, poplar, and straw, and passed through 60 mesh (mesh) sieve. It is possible to obtain a powder and to slurry the powder.

In the present invention, when the wood-based biomass is glycosylated in supercritical water under an acid catalyst, the acid catalyst may be used in an amount of 0.01 to 0.1% (v / v) based on the volume of the reaction solution in which the wood-based biomass and supercritical water are mixed.

In the present invention, when the wood-based biomass is glycosylated in supercritical water under an acid catalyst, any one or more acids selected from hydrochloric acid, acetic acid, nitric acid, and sulfuric acid may be used.

In the present invention, when the wood-based biomass is glycosylated in supercritical water under an acid catalyst, an acid catalyst may be used by mixing one or more acids selected from hydrochloric acid, acetic acid, nitric acid, and sulfuric acid in the same volume ratio.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

1 is a drawing of a saccharification apparatus used for saccharifying woody biomass of the present invention with supercritical water under an acid catalyst.

The saccharification device is a distilled water tank (water tank) 10, a sample tank (20) containing a wood-based biomass, an acid catalyst tank (30), a pump (11) (21) (31), pre-heater (80), line heater (81), reactor (40), heat exchanger (50), separator (60) ) And a receiver 70 for obtaining the end object.

As a safety device of the saccharification device, two relief valves 90 and 91 were installed in front of the preheater 80 and the heat exchanger 50, respectively.

Supercritical water saccharification reaction of the wood-based biomass using the saccharification device is a distilled water of the distilled water tank 10 by the preheater 80, the line heater 81 and the pressure pump (not shown) to the temperature and pressure above the critical point After the supercritical water has passed, the supercritical water is collected from the wood-based biomass and acid catalyst transferred from the sample tank 20 in the reactor 40, and the acid catalyst transferred from the acid catalyst tank 30 is collected in the reactor 40. Under the acid catalyst, the supercritical water is used to crystallize the fibrous component, which is a major component of woody biomass, to monosaccharides to produce monosaccharides.

The supercritical water including the monosaccharide, various wood decomposition products and unreacted wood-based biomass becomes distilled water at room temperature / atmospheric pressure while passing through the heat exchanger 50 outside the reactor, and the monosaccharide passed through the heat exchanger 50. Distilled water containing various wood degradation products and unreacted wood-based biomass is separated from unreacted wood-based biomass by monosaccharides and various wood degradation products in a separator (60) equipped with a filter. The monosaccharides and various wood degradation products can be transferred to the receiving unit 70 connected to the separator 60 to obtain monosaccharides and various wood degradation products from the woody biomass.

The acid catalyst other than the monosaccharide separated from the separator 60 and the unreacted wood-based biomass are separated, and the separated acid catalyst and the unreacted wood-based biomass are each pumped by a pump (not shown in FIG. 1). 30) and the sample tank 20 can be reused or discarded again.

In the acid catalyst tank 30 of the saccharification apparatus of FIG. 1, one or more acid catalysts selected from hydrochloric acid, nitric acid, acetic acid, and sulfuric acid may be added to react wood biomass with supercritical water under such an acid catalyst to saccharify wood biomass. .

Reference numerals 12, 22 and 32 which are not described in the saccharification device of FIG. 1 denote check valves.

Hereinafter, the content of the present invention will be described in detail through examples and test examples. However, these are intended to explain the present invention in more detail, and the scope of the present invention is not limited thereto.

<Example 1>

500 liters of distilled water was prepared in the distilled water tank 10, and 20 liters of Populus alba glandulosa powder in slurry form was filled in the sample tank 20.

The distilled water of the distilled water tank 10 is passed through a preheater 80, a line heater 81, and a pressure pump (not shown) with a pump 11 to obtain a supercritical water having a temperature and pressure above a critical point, and the line heater 81 ) Mixed with the supercritical water and the slurry of the suspension wood powder supplied from the sample tank (2), and then supplying the supercritical water and the slurry of the suspension wood powder to the reactor 40 and then into the acid catalyst tank (30) Hydrochloric acid was added to the reactor 40 in an amount of 0.05% (v / v) relative to the volume of the mixture of the supercritical water and the sludge powder in the form of slurry to the reactor 40 so that the supercritical water and the slurry in the presence of the hydrochloric acid catalyst The wood powder was reacted to saccharify the fibrin component of the woody biomass of sagewood with monosaccharides to prepare monosaccharides.

The reactants after the reaction is passed through the heat exchanger 50 at the bottom of the reactor 40, the supercritical water is changed to distilled water at room temperature / commercial, and the monosaccharide is separated in the separator 60 having a filter. Monosaccharide was stored in the storage unit (70).

The sludge powder in the form of slurries is pulverized into a chip and dried at room temperature after taking a sample, and then pulverized using a planetary mono mill to pass the supercritical water decomposition test, and then filtered through a 60-mesh standard. One powder was used in the form of slurry.

When the supercritical water and the slurry of the suspension wood powder in the form of slurry, the pressure condition of the supercritical water was fixed at 230 ± 10 atm. The temperature of the supercritical water at each pressure condition was 325 ° C, 350 ° C, 380 ° C, 400 ° C and 425 ° C, and the reaction time was performed for 60 seconds each.

Wood monosaccharides produced in the supercritical water glycosylation process under the acid catalyst from the suspension wood powder were measured using high performance ion exchange chromatography (HPAEC, Dionex system). Carbo Pac PA10 column (4 × 250mm) was used as a monosaccharide analysis column, and an ED50 pulsed amperometic detector (PAD) was used as a detector. Mobile phase solvent was used for 3mM NaOH aqueous solution and analyzed for 45 minutes at 0.8ml / min flow rate.

The effect of adding hydrochloric acid catalyst on the supercritical water glycosylation process of wood biomass was primarily the degradation rate of wood biomass. In the case of thorny bark, the wood degradation rate was already degraded about 60% at subcritical temperature of 325 ℃, and it increased significantly as the reaction temperature increased. At 425 ℃, up to 86.7% of wood dry weight was degraded.

The hydrochloric acid catalyst addition effect was found in the yield of wood monosaccharide which is the main object of the present invention. As shown in Figure 2 and Table 1, when the hydrochloric acid catalyst was added, the yield of monosaccharides produced by supercritical water reacted for 60 seconds at 325 ° C, which is a subcritical temperature, reaching 10.5% of the total dry weight. The yield continued to increase, reaching 23%, the highest yield at 380 ° C. The monosaccharide yield tended to decrease over 380 ° C., because the monosaccharide produced was decomposed into furan compounds by secondary decomposition. Looking at the chemical composition of monosaccharides produced during the supercritical water glycosylation process, the most common forms of monosaccharides, glucose and xylose, were relatively high in the range of 325 ℃ to 380 ℃. Glucose was produced by cellulose decomposition.

When the same wood biomass was treated with supercritical water without the addition of hydrochloric acid catalyst under the same conditions, the maximum monosaccharide yield was 3 times higher than that of the total monosaccharide yield compared to the result measured at 425 ° C. Indicated.

Table 1. Influence of Monosaccharide Formation on Saccharification of Suspension Powder in the Presence of Hydrochloric Acid Catalyst

* Table 1 shows arabinose (Ara), galactose (Gal), glucose (Glu), xylose (Xyl), mannose (Man).

<Example 2>

Except for using sulfuric acid instead of hydrochloric acid as the acid catalyst of the acid catalyst tank (30) using the same method as in Example 1 above to saccharify the powder of the hawthorn to obtain a monosaccharide.

Sulfuric acid, which is widely used in the acid hydrolysis of wood biomass, was added to the supercritical water saccharification process of the cultivated wood, and the wood degradation rate and the yield of wood monosaccharides were measured, respectively (see FIG. 3 and Table 2).

The reaction temperature of wood biomass by the sulfuric acid catalyst, the rate of wood decomposition, and the tendency of wood monosaccharide formation according to the reaction temperature were very similar to those of hydrochloric acid, but the yield of wood monosaccharide was less than that of hydrochloric acid.

When the sulfuric acid catalyst was added, the yield of wood monosaccharides produced by the supercritical water reaction was reacted for 60 seconds at the subcritical temperature of 325 ° C. to produce 9% of the total dry weight, which was very similar to the hydrochloric acid catalyst in the initial temperature range. However, the sulfuric acid catalyst addition effect was significantly lower than that of hydrochloric acid catalyst in the yield of wood monosaccharide by supercritical water at about 17-18% of the total weight of wood in the range of 350 ° C to 380 ° C.

Table 2. Effect of Monosaccharide Formation on Saccharification of Poplar Tree Powder in the Presence of Sulfate Catalyst

<Example 3>

Except for using acetic acid instead of hydrochloric acid as the acid catalyst of the acid catalyst tank (30) using the same method as in Example 1 was obtained by saccharifying the powder of the biscuits.

In the present invention, after adding acetic acid which is an organic acid together with inorganic acids such as hydrochloric acid and sulfuric acid, supercritical water saccharification reaction was carried out under the same conditions. Wood degradation rate and yield of wood monosaccharide produced by the addition of acetic acid catalyst are shown in FIGS. 4 and 3.

Acetic acid catalysts showed little catalyst addition effect in the rate of wood decomposition and monosaccharide production, unlike the addition of inorganic acids such as hydrochloric acid or sulfuric acid. The decomposition rate of the hawthorn was about 61% of the total dry weight at 425 ° C., and the yield of wood monosaccharide was only 4.7% of the total dry weight at 400 ° C.

These results indicate that, unlike the inorganic acid, the organic acid acetic acid itself is decomposed under the high temperature and high pressure invented conditions, and thus, it has lost its function as an acid catalyst.

Table 3. Effect on the Monosaccharide Formation of Sapwood Powder in the Presence of Acetic Acid Catalyst

<Example 4>

A monosaccharide was obtained by saccharifying the Rigi pine tree powder using the same method as Example 1 except that Rigida pine powder was used instead of the hawthorn powder as a sample.

Figure 5 shows the total yield of wood monosaccharides produced in the supercritical water glycosylation process for Rigida pine and the amount of each monosaccharide produced. The supercritical water saccharification reaction of Rigida pine was performed at 350 ° C to 425 ° C after adding 0.05% (v / v) hydrochloric acid catalyst to the supercritical water reaction solution. As shown in Fig. 5, the monosaccharide yield was generated about 14% of the total weight of the total dry weight at 350 ℃, and increased significantly as the reaction temperature increased to reach about 25% of the total weight of the total dry weight in the range of 380 ℃ and 400 ℃. Yield tended to decrease.

The wood monosaccharides produced in the supercritical water glycation process of Rigida pine reflect the composition of typical conifer species monosaccharides such as mannose, xylose and galactose in addition to glucose. In the subcritical temperature range, hemicellulose was mainly decomposed to produce mannose and gyro, and above 380 ° C., a supercritical temperature, the amount of glucose produced by the decomposition of cellulose was greatly increased. Above 425 ° C, the monosaccharides produced were pyrolyzed into furan compounds by the high temperature in the reactor, so monosaccharide yield tended to decrease.

<Example 5>

Lactose powder was glycosylated using the same method as Example 1, except that larch powder was used instead of the thorn tree powder as a sample, thereby obtaining monosaccharides.

Figure 6 shows the total yield of wood monosaccharides produced during the supercritical water glycosylation process and the amount of each monosaccharide produced in larch. Supercritical water glycation reaction was carried out under the same conditions as Rigida pine. As shown in Figure 6, the monosaccharide yield was produced about 14% of the total weight of the dry wood at 350 ℃, the reaction temperature is increased significantly as the temperature reached a maximum of about 25% of the total weight of dry wood in the range of 380 ℃ and 400 ℃, Post monosaccharide yield tended to decrease gradually.

<Example 6>

The monosaccharide was obtained by saccharifying the lily tree powder in the same manner as in Example 1, except that the lily tree powder was used instead of the suspension tree powder as the sample.

Figure 7 shows the total yield of wood monosaccharides produced during the supercritical water glycosylation process and the production amount of each monosaccharide. In the case of lily tree, the monosaccharide production rate of 28% of the total weight of the total dry weight in the supercritical water glycosylation process at 400 ° C. for 60 seconds was the highest as compared with the present-day tree, Rigi pine and larch.

<Example 7>

Rice straw was glycosylated using the same method as Example 1, except that rice straw was used instead of thorny powder as a sample to obtain monosaccharides.

8 shows the total yield of monosaccharides produced in the supercritical water saccharification process and the amount of each monosaccharide produced in rice straw. Rice straw is generally classified as herbaceous biomass rather than woody. The chemical composition of rice straw was about 65% of the cellulose component (cellulose + hemicellulose) that produces monosaccharides, which is similar to that of ordinary wood biomass, while the lignin component was much lower than that of wood biomass.

As shown in FIG. 8, rice straw showed a monosaccharide yield lower than that of wood biomass in all temperature ranges as a result of performing supercritical water saccharification under the same conditions as other wood biomass. Rice straw produced about 16% of monosaccharides when reacted at 380 ° C. for 60 seconds. Most of them were xylose and glucose. In addition, a relatively high proportion of arabinose was detected in rice straw supercritical water glycation products compared to wood biomass.

As described above, although described with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and modified within the scope of the present invention without departing from the spirit and scope of the invention described in the claims below. It will be appreciated that it can be changed.

Currently, ammonia treatment and weak acid treatment are in the research stage as pretreatment technology of wood biomass for monosaccharide production. Monosaccharide conversion technology includes acid hydrolysis and enzymatic reaction, but it is still below the level of practical use. Wood biomass is generally made up of more than 70% of the fiber component, and because of its renewable nature, bioethanol is attracting attention as the only natural resource to replace the starch system. However, it is true that the saccharification process is not easy because wood-based cellulose has a crystalline structure. The saccharification process of the wood-based biomass by supercritical water according to the present invention is likely to be practical in that the reaction time is very short and the process stability can be secured because water is used as the decomposition medium.

The present invention is a technology for producing a large amount of wood monosaccharides (glucose + gyros + mannose) by hydrolyzing the fiber component (cellulose + hemicellulose) of wood biomass in a short time in the future to replace wood biomass in place of starch biomass. It can be used as a major resource for bioethanol production feedstock.

1 is a diagram showing an example of an apparatus used for the saccharification reaction of wood biomass in supercritical water under an acid catalyst.

Figure 2 is a graph showing the decomposition rate and monosaccharide production yield of the suspension of the suspension according to the addition of the hydrochloric acid catalyst of Example 1.

Figure 3 is a graph showing the decomposition rate and yield of monosaccharides of the suspension according to the addition of sulfuric acid catalyst of Example 2.

Figure 4 is a graph showing the decomposition rate and monosaccharide production yield of the suspension of the suspension according to the addition of acetic acid catalyst of Example 3.

FIG. 5 is a graph showing the yield of monosaccharides of Rigida pine according to the addition of the hydrochloric acid catalyst of Example 4. FIG.

Figure 6 is a graph showing the yield of monosaccharides of larch according to the addition of the hydrochloric acid catalyst of Example 5.

Figure 7 is a graph showing the yield of monosaccharides of the lily tree according to the addition of the hydrochloric acid catalyst of Example 6.

8 is a graph showing the yield of monosaccharides in rice straw according to the addition of the hydrochloric acid catalyst of Example 7.

Claims (5)

In saccharifying woody biomass, A method for saccharifying wood-based biomass using an acid catalyst and supercritical water, characterized in that monosaccharide is produced from wood-based biomass by saccharifying wood-based biomass with supercritical water under an acid catalyst. The saccharification of wood-based biomass using an acid catalyst and supercritical water according to claim 1, wherein the wood-based biomass is saccharified for 10 seconds to 120 seconds with a supercritical water at a pressure of 218.3 to 340 atm and a temperature of 325 to 425 ° C. Way. The method of claim 1, wherein the wood-based biomass is a saccharification method of the wood-based biomass using an acid catalyst and supercritical water, characterized in that any one selected from sage, rigi pine, larch, lily, poplar, rice straw. The method for saccharifying woody biomass using the acidic catalyst and supercritical water according to claim 1, wherein the acidic catalyst is used in an amount of 0.01 to 0.1% (v / v) based on the volume of the mixture of the woody biomass and the supercritical water. The method of claim 1, wherein the acid catalyst is one or more selected from hydrochloric acid, acetic acid, nitric acid, sulfuric acid, characterized in that the saccharification method of wood-based biomass using an acid catalyst and supercritical water.

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