KR100748551B1 - Method and apparatus for cellulose acetate - Google Patents

Abstract

Provided are a method for preparing cellulose acetate without using lactic acid, and an apparatus for preparing cellulose acetate to reduce the cost for equipment by lowering the internal pressure of a container. A method comprises the steps of applying overheated vapor to the piece assembly of wood-based material containing a solid catalyst (preferably with the overheated vapor at a temperature of 400-800 deg.C and at a pressure of 0.1-5 MPa for 15-240 min) to separate a cellulose component; purifying the separated cellulose component; and pressurizing the purified cellulose component with a solid acid to obtain cellulose acetate. Preferably the wood-based material has a diameter of 0.01-5 mm.

Description

Cellulose acetate manufacturing method and apparatus {Method and Apparatus for CELLULOSE ACETATE}

1 is a process chart showing the manufacturing process of cellulose acetate in accordance with the present invention.

2 is a flowchart showing each process according to FIG.

Figure 3 is a schematic overall configuration of the manufacturing apparatus of cellulose acetate according to the present invention.

Figure 4 is a schematic diagram of a superheated steam generating apparatus according to the present invention.

5 is a schematic explanatory diagram of a superheated steam generating device according to the present invention;

6 is a cutaway view showing an example of the pipeline arrangement method according to FIG.

Figure 7 is an explanatory diagram showing another example of the arrangement method of the conduit of the superheated steam generating apparatus according to the present invention,

8 is a characteristic diagram showing the results of experiments to prove the action of the superheated steam generating apparatus according to the present invention,

Figure 9a is a schematic longitudinal side view of the high temperature steam reactor according to the present invention,

Figure 9b is a front view showing the appearance of the high temperature steam reactor according to Figure 9a,

10 is a front view schematically showing a pyrolysis reaction apparatus according to the present invention.

* Explanation of symbols on the main parts of the drawing

10: luxury means 11: steam boiler 20: superheated steam generating device

21: water vapor inlet 22 22: heat exchange pipe 23: water vapor outlet

24 burner 30 high temperature steam reactor 31 reactor body

32: lid 33: superheated steam inlet 34: drain outlet

35 exhaust port 36 cartridge 37 copper plate

40: purification means 41, 80: filtration device 42, 90: washing and dehydration device

43: drying apparatus 50: vaporization means 60: photochemical reaction device

61 reactor body 62 superheat jacket 63 stirrer

64: stirring blade 65: cellulose acetate outlet 66: recovery pipe

70: recovery device 611: cellulose inlet 612: solid catalyst inlet

613: superheated steam inlet 614: glacial acetic acid inlet

615: drain outlet 616: additive inlet

P1: first stage pipeline P2: second stage pipeline P3: third stage pipeline

T: Piece Assembly

The present invention relates to a method and apparatus for producing cellulose acetate, and more particularly, to a method for producing cellulose acetate useful as a raw material of biodegradable plastics using wood-based materials including pieces of corncob meal. More specifically, in the case of producing cellulose acetate through the process of increasing the volume of wood-based material such as corn cob flour and subjecting the cellulose component separated by the gelatinization process to purify the cellulose component after purification, the cellulose acetate is produced under low pressure. The process becomes possible. In addition, the present invention relates to a method and apparatus for producing cellulose acetate, in which it is unnecessary to perform a dehydration treatment involving lactic acid in the nitriding process.

Conventionally, corn cob flour obtained by drying and crushing corn cob (seed) is subjected to gelatinization process, and then the solids are separated by a filtration device to obtain a cellulose component. It is proposed as a manufacturing method.

In the method for producing cellulose acetate, which has been proposed by Japanese Patent Application Laid-Open No. 2004-27056, which is known in the art, the subcritical state (the state immediately before reaching supercritical water) of corn cob flour to which the gelatinization process is added It is carried out in a pressure vessel kept at a temperature of 150 to 250 ° C. and a pressure of 20 to 29 MPa. That is, in this gelatinization process, the screw accommodated in the hermetic cylinder is rotated to push out the material while compressing the material. In this process, the gelatinization process conditions are maintained at a temperature of 150 to 250 ° C and a pressure of 20 to 29 MPa.

In addition, the gelatinization process is designed to shorten the gelatinization time by adding a nitrite compound such as sodium sulfite or calcium nitrate to the corn flour.

In addition, in the conventionally proposed method of manufacturing cellulose acetate, a process of reacting by adding acetic anhydride and lactic acid to the cellulose component is carried out as a step of initializing the separated cellulose component after the gelatinization process.

According to such a conventional method for producing cellulose acetate, corn cob flour that has been treated as a waste that is burdened by agricultural producers can be effectively used as a raw material of cellulose acetate, and the cellulose acetate produced by the production method By using the as a raw material of biodegradable plastics, it is possible to produce biodegradable plastics at relatively low cost.

However, the method for producing cellulose acetate needs to maintain the gelatinization process conditions at a high pressure of 20 to 29 MPa at a temperature of 150 to 250 DEG C. As a pressure vessel used in the gelatinization process, it has a compression function and a pushing function of the above materials. Since there is a need to use a sealed cylinder having a high pressure resistance of a built-in screw type, there is a problem that the installation cost of the pressure vessel becomes high. In addition, there is a problem in that the risk is high because it is necessary to handle the lactic acid in the process of mineralization.

In order to solve the problems described above, in the present invention, the pressure in the gelatinization process in the cellulose acetate production method subjected to the gelatinization treatment and the nitriding treatment can be significantly lowered than before, thereby reducing the pressure resistance performance of the pressure vessel used in the gelatinization treatment. It is possible, and an object of the present invention is to provide a method and apparatus for producing cellulose acetate, which does not require the use of a high risk of lactic acid in the initial treatment of the separated cellulose component after gelatinization.

In the production method of the present invention for achieving the above object, by separating the cellulose component and purifying the separated cellulose component by performing a gelatinization process (S10) by acting superheated steam on a piece of wood-based material to which a solid catalyst is added After the step (S20) and the solid acid under pressure with the solid acid step (S30) is characterized in that the cellulose acetate is obtained.

On the other hand, the gelatinization step (S10) acts 15 to 240min of superheated steam at 400 to 800 ° C under a pressure of 0.1 to 5MPa on the piece aggregate of the wood-based material to which the solid catalyst is added, and at the gelatinization step (S10). The solid catalyst to be added to the aggregate of materials is one or more selected from platinum, titanium oxide, cerium oxide, yttrium oxide, thorium oxide, stone oxide, zinc oxide, manganese oxide, aluminum oxide, silicon oxide, and vanadium oxide. The solid catalyst is added in an amount of 1 to 20 wt% of the dry weight ratio based on the wood-based material.

Here, the particle size of the wood-based material is characterized in that the diameter of 0.01 to 5mm.

In addition, the step of nitriding (S30) includes a step of producing cellulose acetate and acetic acid by adding and reacting cellulose component and glacial acetic acid having a dry weight ratio of 300 ~ 700 (wt%) with respect to cellulose, the amount of the solid acid is added Dry weight ratio of 1 to 20 (wt%), the solid acid is characterized by using at least any one or more of synthetic zeolite (zeolite), molten zeolite, clinofucciol zeolite.

In addition, in the initialization step (S30), the reaction temperature is 70 ~ 130 (℃), the reaction pressure is 0.1 to 5 (MPa), the reaction time is characterized in that the 30 to 300 (min).

The manufacturing apparatus of the present invention for achieving the above object, the purifying means (10), a purifying means 40 consisting of a filtering device washing dehydration device drying apparatus for purifying the processed product, and the purifying means In the manufacturing apparatus (100) including the means for superposing | reacting 50 which oxidizes the cellulose produced | generated by 40;

The luxury means 10 is a water vapor inlet 21 connected to the steam engine passage 111 of the steam boiler 11, a heat exchange pipe passage 22 connected to the water vapor inlet 21, and the heat exchange tube 22 A superheated steam generating device (20) comprising a water vapor outlet (23) connected to an end and a burner (24) provided at a lower end of the heat exchange tube (22); The pressure gauge 322 is provided on the lid 32 detachable by the fastener 321 in the upper portion, and the superheated steam inlet 33 is provided below the lid 32 to be connected to the water vapor outlet 23. The reaction body main body 31, which is a hollow body composed of a lower drain outlet 34 and an exhaust port 35 provided on the lower side, and a net body 38 inside the oil hole bottom plate 371 provided with a plurality of water vapor passage holes 372. The hot-plate steam reaction consisting of the cartridge 36 installed in the space between the inlet 33 and the drain outlet 34 and the exhaust port 35 inside the reactor body 31 of the cylindrical copper plate (37) is mounted. Device 30,

The initializing means 50 includes a cellulose inlet 611 for injecting the purified cellulose on the reaction tank body 61, a solid catalyst inlet 612 for injecting a solid catalyst or a solid acid, and a recovery pipe 66 ) Is provided, and a steam inlet 613 connected to the water vapor outlet (23), a glacial acetic acid inlet (614) and an additive inlet (616) are provided on the side of the reaction tank body (61) to inject superheated steam as a heat source. A drain outlet 615 and a cellulose acetate outlet 65 are provided below the reaction tank body 61, and the stirring blade 64 rotates by the stirrer 63 inside the reaction tank body 61, and a circumferential direction. A superheat reaction apparatus 60 composed of a superheated jacket 62 formed of; It is characterized in that consisting of a recovery device 70 is connected to the recovery pipe 66 provided in the reaction apparatus 60, the recovery pipe 66 is provided with a condenser 71.

Here, the heat exchange pipe line 22 is a three-stage first stage pipe (P1), the second stage pipe (P2), the third stage bureau (P3) between the steam inlet 21 and the steam outlet (23) It consists of three stages, the first stage pipe (P1) and the second stage pipe (P2) is connected in parallel with the second stage pipe (P2) and the third stage bureau (P3) is connected in parallel It is characterized by.

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

1 is a process chart showing a manufacturing process of cellulose acetate according to the present invention, FIG. 2 is a flowchart showing each process according to FIG. 1, and FIG. 3 is a schematic diagram showing an overall configuration of an apparatus for producing cellulose acetate according to the present invention. 4 is a schematic configuration diagram of a superheated steam generating apparatus according to the present invention, FIG. 5 is a schematic explanatory diagram of the superheated steam generating apparatus according to the present invention, and FIG. 7 is an explanatory view showing another example of the method of arranging the conduits of the superheated steam generating apparatus according to the present invention, and FIG. 8 shows the experimental results to prove the operation of the superheated steam generating apparatus according to the present invention. Figure 9a is a schematic longitudinal sectional side view of the high temperature steam reactor according to the present invention, Figure 9b is a front view showing the appearance of the high temperature steam reactor according to Figure 9a, Figure 10 is a schematic diagram of the reaction apparatus according to the present invention A front view showing a.

In the method for producing cellulose acetate according to the present invention, the supernatant steam is applied to a piece of wood-based material to which a solid catalyst is added, the cellulose component is separated by the gelatinization process (S10), and the separated cellulose component is purified after the purification process (S20). The cellulose acetate is obtained by the step of solidification (S30) under pressure with the solid acid. In the present invention, it is possible to use a piece of a required amount obtained by crushing corn shim (corn cove), for example, into a piece of wood-based material.

According to the present invention, a method of performing the gelatinization process (S10) by adding a solid catalyst to the gelatinization process (S10), which is carried out by acting superheated steam on a piece of wood-based material, is carried out smoothly at a relatively low pressure. do. The gelatinization step (S10) is a process in which granulated or powdered pieces of wood-based material are enclosed in a pressure vessel together with a solid catalyst to send super high temperature water vapor to the solid catalyst, platinum, titanium oxide, cerium oxide, yttrium oxide, and oxide. It was found that one or more kinds selected from thorium oxide, zinc oxide, zinc oxide, silicon oxide, and vanadium oxide can be obtained.

The particle size of the pieces contained in the piece aggregate is preferably 0.01 to 5 mm in terms of length. If the particle size (grain size) is smaller than this range, it is difficult to form gaps in the layers of the piece aggregate and overheat. It is difficult to obtain a constant gelatinization action because the gelatinization is difficult to reach the entire set of pieces by water vapor. On the other hand, if the particle size is larger than the above range, the size of the sculpture is so large that there is a possibility that the gelatinization action due to superheated steam on the individual sculpture may be insufficient, and the gelatinization time may be consumed to solve the problem. . And if the particle size of the fragment is within the above range, although the gelatinization process (S10) can be performed at a constant short time, the gelatinization action by superheated steam on the individual fragments is sufficiently widespread and the whole of the aggregate is uniform. The recovery rate of the cellulose component which was gelatinized becomes high. When the wood-based material is corn cob, the particle size of the piece aggregate is preferably 0.05 to 2 mm, more preferably 0.1 to 1 mm, and the particle size is 0.05 to 2 mm or 0.1 to 1 mm. As a result, the gelatinization action by the superheated steam is efficiently carried out to shorten the gelatinization process (S10) time, or the gelatinization process (S10) is easily performed to control the temperature and pressure of the superheated steam.

The amount of the solid catalyst used in the gelatinization step (S10) is preferably 1 to 20wt% based on the dry wood-based material. The solid catalyst can be selected from platinum, titanium oxide, cerium oxide, etc. as a suitable kind to be used as it is thought that it is helpful to promote the gelatinization action by superheated steam under high temperature pressure. The addition amount of the solid catalyst is determined based on the weight of the dry wood-based material, and when the addition amount is smaller than the above range, sufficient catalytic action cannot be exhibited. Conversely, even if more solid catalysts are added than the above ranges, the effect of the addition is saturated, and the solid catalysts are consumed uselessly. In the case where the wood-based material is corn cove, the preferred amount of addition is 3 to 15 wt%, and more preferably 5 to 10 wt%.

In said gelatinization process (S10), it is preferable to apply superheated steam of 400-800 degreeC to the piece aggregate of the wood-based material to which the solid catalyst was added under the pressure of 0.1-5 Mpa.

In the geological process (S10) of the present invention, the superheated steam temperature is about 250 to 550 ° C. higher than the conventional method described in the introduction, while the processing pressure is 0.1 to 5 MPa, which is about 19.9 to 24 MPa lower than the conventional method. It is. Since the superheated steam is obtained by a boiler separate from the pressure vessel used in the gelatinization process (S10), the pressure resistance of the pressure vessel used in the gelatinization process (S10) ends significantly lower than in the conventional case, and the work costs the equipment cost. It helps to reduce significantly. The cellulose component obtained by applying 400-800 ° C. superheated steam at a pressure of 0.1-5 MPa to such a piece of wood-based material has a high whiteness and is compared with the cellulose component obtained when cotton is used as a raw material. Even if it is inferior, it turns out that the cellulose component which can be obtained by the gelatinization process (S10) concerning this invention is high in purity.

The temperature of the superheated steam in the gelatinization step (S10) is preferably 500 to 700 ° C, more preferably 550 to 600 ° C. It is relatively easy to obtain superheated steam in these temperature ranges, and in particular, superheated steam at 550 to 600 ° C can be obtained using a relatively inexpensive superheated steam generator.

Although the pressure condition of the said gelatinization process S10 may be controlled in the range of said 0.1-5 Mpa, Preferably it is 0.2-3 Mpa, More preferably, it is 0.5-1 Mpa. Among them, the pressure of 0.5 to 1 MPa is a low pressure, and it helps to promote the reduction of the equipment cost more remarkably for the pressure vessel used for the gelatinization process (S10).

In the above gelatinization step (S10), when the superheated steam at 400 to 800 ° C. is operated under a pressure of 0.1 to 5 MPa in a piece of wood-based material to which the solid catalyst is added, the action time of the superheated steam is preferably 15 to 240 min. Do. While the operating time of superheated steam is shorter than this range and sufficient gelatinization action may not be obtained, the operating time of superheated steam is longer than this range and superheated steam is unnecessarily consumed, so that the time required for gelatinization process (S10) is long. It is spent unnecessarily. Preferred working time is 30 to 180 min, and more preferably 45 to 120 min.

In the method for producing cellulose acetate according to the present invention, cellulose acetate is obtained by separating and producing the cellulose component obtained in the gelatinization step (S10) and subjecting the solidification step (S30) to treatment with a solid acid. The step (S30) includes a step of producing a cellulose acetate and acetic acid by reacting the cellulose component and glacial acetic acid. Specifically, the cellulose component is encapsulated with a solid acid and glacial acetic acid, called mordenite (morden zeolite) or crinophthyrolite (Crynophthylori zeolite), in a pressure vessel and subjected to a dehydration substitution reaction under high temperature and high pressure conditions. . Since cellulose acetate can be obtained through this treatment, the lactic acid used in the initializing step (S30) of the conventional manufacturing method becomes unnecessary, and the risk burden of the initial step (S30) is eliminated.

As the solid acid used in the above-mentioned step (S30), a mordenite, a Crinophorus ruby and other synthetic zeolites may be used. The activity of zeolite as a solid acid is due to the activity of hydrogen atoms fixed inside the zeolite. However, if the amount of zeolite added is overwhelmingly, the activity as cation exchange material is more than that of acid. As a result, activity as a proton point (scatter point) is impaired. The amount of the solid acid added may be 1 to 20 wt% with respect to the dry cellulose component. If the amount of added solid acid is less than this range, there is a possibility that sufficient dehydration substitution reaction cannot be obtained. If the amount of added solid acid is more than this range, the effectiveness as a proton point (acid point) is lost when zeolite is used as the solid acid. The preferred amount of the solid acid is 3 to 15 wt%, more preferably 5 to 10 wt%, and if the amount of the solid acid is set within these preferred ranges or within a more preferred range, the solid acid can contribute to the dehydration substitution reaction without excess and deficiency.

The amount of glacial acetic acid used in the above-mentioned step (S30) may be 300 to 700 wt% based on the dry cellulose component. Cellulose has three “apparatuses” as reactors. The degree of nitriding is theoretically three times that of cellulose, but in actual chemical reactions, the activation energy is round (cyclic) and requires the remaining acetic acid. Specifically, the amount of acetic acid added does not proceed in the amount of three times the theoretical value, and acetic acid in an amount of five to seven times is required. In addition, glacial acetic acid (anhydrous acetic acid) is used instead of acetic acid because the reaction of cellulose is dehydrated, so that less water is more likely to react. It is for this reason that conventionally, dehydration catalysts, such as lactic acid, are used. If the amount of glacial acetic acid is less than the above-mentioned range, it is not an advantageous solution because the required supernatant is not achieved, and if the amount of glacial acetic acid is more than this range, the remaining acetic acid is generated and becomes obsolete, and the need for recovery and concentration is increased. The preferred amount of glacial acetic acid is 400 to 600 wt% and more preferably 450 to 500 wt%, and then the amount of glacial acetic acid is set within these preferred ranges or even more within these preferred ranges can contribute to the dehydration reaction without glacial acetic acid.

As for the initialization reaction temperature in the said initialization process (S30), 70-130 degreeC is suitable. The reaction temperature does not necessarily have to be in this range, but in order to remove the water separated by the reaction as water vapor in addition to the system, a temperature of 100 ° C. or more is required. If the temperature is higher than necessary, acetic acid itself becomes a vapor and flows out of the system. Therefore, in order to prevent this, it is better to suppress the reaction temperature to the minimum required. For example, in the test at 160 ° C, the entire cellulose injected does not react, causing the problem of partial growth. This is not only a matter of temperature, but also related to the performance of the stirring device. However, it is impossible to deny that temperature control is important even in a control relationship because it is preferable that the entire cellulose injected is reacted at the intended degree of supernatant. There is a concern that the reaction temperature is higher than the above range and that the reaction proceeds partially to impair the overall balance, whereas if it is lower than this range, the reaction may not proceed smoothly. Preferable initialization reaction temperature is 80-120 degreeC More preferably, the reaction temperature is 90-110 degreeC.

In addition, the pressure condition in the step (S30) is 0.1 to 5 MPa, and the reaction at high pressure above this range may cause a slow reaction. The reaction at low pressure below this range does not sufficiently separate water from cellulose. There is no fear. Preferred pressure is 0.2 to 3 MPa, more preferably 0.5 to 1 MPa.

The reaction time is preferably set to 30 to 300 minutes, preferably 80 to 240 minutes, more preferably 120 to 180 minutes.

1 is a process diagram illustrating a manufacturing process of cellulose acetate according to the present invention, the manufacturing method includes a gelatinization step (S10), a purification step (S20), a cementation step (S30). Each process will be described with reference to the respective process flow diagram shown in FIG.

The luxury step S10 is an example of a piece aggregate of wood-based materials. A solid catalyst is added to the powdered corn cob (corn cob flour), encapsulated in a pressure vessel, and a super high temperature steam is applied to the pressure vessel.

 It is possible to use one or more kinds of solid catalysts selected from platinum, titanium oxide, cerium oxide, yttrium oxide, titanium oxide, stone oxide, zinc oxide, manganese oxide, aluminum oxide, silicon oxide and vanadium oxide. In the embodiment, titanium oxide, yttrium oxide, cerium oxide, and cerium oxide as solid alkali media were used alone among these solid catalysts.

In addition to using powder aggregates having a particle size distribution of 0.01 to 5 mm in terms of length, a powder aggregate having a particle size distribution of 0.05 to 2 mm or aggregates having a particle size distribution of 0.1 to 1 mm is also used. Tested that. As a result, it was found that the use of supernatant aggregates with a particle size distribution of 0.01 to 5 mm sufficiently resulted in gelatinization by superheated steam on individual fragments, and the entire fragment aggregate was uniformly gelatinized to increase the recovery of cellulose components. . In the case of a particle size distribution of 0.05 to 2 mm or 0.1 to 1 mm, the size of the pieces contained in the aggregates is averaged, so that the gelatinization action by the superheated steam is performed efficiently, so that the gelatinization process (S10) time can be shortened easily. It was found that the temperature and pressure of the superheated steam as the gelatinization step (S10) conditions can be easily controlled.

The amount of solid catalyst added was 1-20 wt% for dry powder corn cobs and 5-10 wt% for 3-15 wt%, but there was no excess or deficiency in the amount of fixed medium in the range of 1-20 wt%. Furthermore, it was found that sufficient catalysis was exerted. Such a situation was found to be remarkable when the addition amount was 3 to 15 wt% or when it was 5 to 10 wt%.

The temperature of superheated steam was 400-800 degreeC, and the pressure in the hot steam reactor 30 was kept at 0.1-5 Mpa. Moreover, when the temperature of superheated steam was 500-700 degreeC and 550-600 degreeC, it also performed also when the pressure in the high temperature steam reaction apparatus 30 was changed to 0.2-3 MPa or 0.5-1 MPa.

Since hemicellulose (soluble xsilane) other than a cellulose component was obtained by the hydrolysis reaction in a gelatinization process (S10), the refinement | purification process (S20) of a cellulose component was performed after gelatinization process (S10).

The treatment time in the said luxury process (S10) selected three types of 15-240min, 30-180min, and 45-120min.

[Refining process]

Purification step (S20) is a process of separating the cellulose component from the product and the residue of the hydrolysis reaction in the gelatinization step (S10), and recovered the cellulose component by performing each step of filtration, washing and drying as shown in FIG. The hemi cellulose was separated and recovered because the solid catalyst was reused.

The cellulose component separated by the refining step (S20) had no inferiority with the cellulose component obtained when the cotton was used as a raw material even in the above conditions (temperature of superheated steam, pressure, type of solid catalyst, etc.). .

[Process of initialization]

The nitriding step (S30) includes a step of producing cellulose acetate and acetic acid by reacting the cellulose component with glacial acetic acid. Specifically, the cellulose component is encapsulated in the reaction apparatus together with a solid acid and glacial acetic acid, and causes a dehydration substitution reaction (oxidation reaction) under high temperature and high pressure conditions. Filtrate and residue were filtered and washed in this refining step (S30), and each step was carried out to separate cellulose acetate, and the filtrate or catalyst was recovered, and the catalyst was used for reuse.

In the above-mentioned step (S30), cellulose acetate which can be suitably used as a raw material of biodegradable plastics can be obtained without using the lactic acid used in the step (S30) of the conventional manufacturing method described at the beginning. Specifically, the cellulose acetate has a rate of 55.2% to 57.0% with a whiteness of 92%.

It was confirmed that the solid acid used in the initial step (S30) was obtained by using mordenite, Crinofchirurubine, and synthetic zeolite. It was also confirmed that the amount of the solid acid added was 1 to 20 wt% with respect to the dry cellulose component, the preferred amount was 3 to 15 wt%, and the more preferable amount was 5 to 10 wt%.

The addition amount of glacial acetic acid used for the initialization process (S30) should just be 300-700 wt% with respect to a dry cellulose component, Preferably it was 400-600 wt%, More preferably, it confirmed that it is 450-500 wt%.

It was also confirmed that 70-130 degreeC is suitable for the initialization reaction temperature in a initialization process (S30), Preferably it is 80-120 degreeC, More preferably, it is 90-110 degreeC.

It was also confirmed that the pressure conditions in the initialization step S30 are 0.1 to 5 MPa, preferably 0.2 to 3 MPa, and more preferably 0.5 to 1 MPa.

Moreover, although it is suitable to set the reaction time to 30-300min, Preferably it is 80-240min, More preferably, it may be 120-180min.

Figure 3 is a schematic configuration diagram showing the overall configuration of the manufacturing apparatus of cellulose acetate according to the present invention with reference to this as follows.

The apparatus for producing cellulose acetate is a steaming means (11) consisting of a steam boiler (11), a superheated steam generating device (20), a hot water steam reaction device (30) for gelatinization, and purifying the gelatinized product. Purification means (40) consisting of a filtration device (41), a washing and dehydration device (42), a drying device (43) for the reaction, and a superposition reaction device for carrying out the cellulose reaction produced by the purification means (40) ( 60), and the recovery device 70 is provided with a condenser 71, and the means 50, after the reaction after the filtration device 80, washing dehydration device 90 and the drying device 43 Is generated.

First, the steam boiler 11 generates steam at 110 to 130 ° C. in kerosene or A heavy oil, etc., and transmits steam at 110 to 130 ° C. to the superheated steam generator 20 through the steam pipe 111 to 400 to 600 ° C. The apparatus of overheating by the apparatus of the "2 n-1 multistage heating structure" will be described in detail later.

On the other hand, the high temperature steam reactor 30 is a mixture of the superheated steam in the superheated steam generator 20 and the wood-based material (for example corn cob flour) and the solid catalyst in the mixing device 12 is a low-pressure superheated steam It is a device for increasing steam, and the raw materials introduced therein are hydrolyzed by solid catalyst and superheated steam.

Hydrolysis here refers to decomposing lignocellulosic, a major constituent of wood-based materials, to obtain cellulose and hemicellulose, which has been mechanically crushed or gelatinized for a long time using an alkali contractor. It can be processed in a short time at low pressure without using an alkali contractor.

On the other hand, the filtration step is to use the filtration device 41 by separating the raw material steamed in the hot water steam reactor 30 into a solid (cellulose) and a liquid (hemicellulose).

The filtrate can be used as a raw material, such as chishiro oligosaccharides, including hemicellulose and polyphenols, and is recovered and stored in a storage device (not shown).

The cellulose separated by filtration by the filtration device 41 is washed with water (washing) and dehydrated by the washing and dehydrating device 42 and then introduced into the drying device 43, and the drying device 43 is driven by dry steam. .

The reaction reactor 60 is made of a material having good acid resistance such as titanium, and actuated by drying sulfuric acid, glacial acetic acid and the like on dry cellulose.

Cellulose (cellulose acetate), which has been purified by the reaction apparatus 60, is separated by a filtration apparatus 90, washed with water by a dehydration apparatus 90, washed, dehydrated, and dried again by the drying apparatus 43. Cellulose acetate product to be obtained.

The cellulose acetate manufacturing apparatus 100 shown here is performed by manual input, discharge, transfer, recovery, etc. all by hand.

However, although not shown in FIG. 3, drainage or recovery of wastewater is transferred to a storage tank by using a drain pipe and a pump.

4 to 10 is a superheated steam generating device 20 used in the gelatinization step (S10) in the cellulose acetate manufacturing apparatus, a high temperature steam reaction device 30 as a pressure vessel used in the gelatinization step (S10), a step of nitriding (S30) It will be described in detail for the reaction apparatus 60 used in the.

[Superheated steam generator]

4 is a schematic configuration diagram of a superheated steam generating apparatus, FIG. 5 is a schematic explanatory diagram of a superheated steam generating apparatus, FIG. 6 is a cutaway view showing an example of a pipeline arrangement method according to FIG. 5, and FIG. 7 is an overheat according to the present invention. Explanatory drawing showing another example of the method of arranging the conduits of the steam generator, FIG. 8 is a characteristic diagram showing the results of experiments to prove the operation of the superheated steam generator according to the present invention.

In FIG. 4, the steam boiler 11 should just be able to generate | occur | produce steam, Preferably it is good to generate | occur | produce 110-130 degreeC steam. As long as this condition is satisfied, the specific structure of the steam boiler 11 may be anything.

The basic configuration of the superheated steam generating device 20 is arranged to arrange the heat exchange tube path 22 formed by the piping of the heating zone (Z) implemented by the operation of the burner (24). In the heating zone Z, the heating action is heated by the burner 24 provided below the heat exchange pipe passage 22. In addition, the heat exchange pipe line 22 is provided with a steam inlet 21 and a steam outlet 21 for taking out superheated steam to introduce steam generated by the steam boiler 11.

In the superheated steam generating device 20, the heat exchange pipe line 22 schematically shown in FIG. 5 is partitioned into a plurality of pipes from the water vapor inlet 21 to the water vapor outlet 21, and the cross-sectional area of the rear side side pipe is defined. One example of the specific configuration will be described next, which is larger than the cross-sectional area of the pipe on the shear side.

In the example of FIG. 5, the heat exchange pipe line 22 disposed in the heating zone Z in the superheated steam generating device 20 has a three-stage pipe line P1, from the water vapor inlet 21 to the water vapor outlet 21. The water vapor flowing through the pipes P1 and P2 is in a countercurrent direction by connecting the first-stage pipe P1 and the second-stage pipe P2 in parallel with each other. In this way, by connecting the two-stage pipe (P2) and the three-stage pipe (P3) in parallel with each other, the water vapor flowing through the pipes (P2, P3) in the countercurrent direction. (The flow direction of water vapor is shown by the arrow in FIG. 5) As can also be seen from FIG. 5, the pipes P1, P2 and P3 of the three stages of the heat exchange pipe 22 use pipes having the same cross-sectional area (diameter). On the other hand, by changing the number of pipes used by the pipes (P1, P2, P3), the cross-sectional area of the two-stage pipe (P2) is larger than the one-stage pipe (P1), and thus the three-stage pipe (P3) rather than the two-stage pipe (P2). ) Has a larger cross-sectional area. More specifically, the first stage pipeline (P1) is made by doubling the number of tubes used in the second stage pipeline P2 (two in the example) and twice the number of tubes used in the first stage pipeline P1 (one in the example). The cross-sectional area twice the cross-sectional area of) is given to the two-stage pipe (P2). As such, the number of tubes used in the three-stage pipeline (P3) (four in the example) is doubled to the number of tubes used in the second stage (P2) (two in the example). The cross-sectional area of twice the cross-sectional area of is given to the three-stage pipe line P2. Therefore, in the three-stage pipelines (P1, P2, P3), their cross-sectional area is doubled every time the number of stages increases. In other words, the cross-sectional areas of the three-stage pipelines (P1, P2, P3) are single-stage. Is proportional to

In the superheated steam generating apparatus 20 described with reference to FIGS. 5 and 6, the pipes P1, P2, and P3 are connected in a serpentine form, and the entire heat exchange pipe line 22 is compared with the case where they are connected in a straight shape. ) Can be arranged into a compact shape.

Fig. 7 shows an example of the superheated steam generating device 20 whose pipe arrangement is different from that in Fig. 5.

In the example of FIG. 7, the heat exchange pipe line 22 disposed in the heating zone Z is a four-step pipe line (P1, P2, P3, P4) from the steam inlet (not shown) to the water vapor outlet (not shown). It is partitioned on. And by connecting the first stage pipeline (P1) and the second stage pipeline (P2) in parallel with each other so that the water vapor flowing through their pipelines (P1, P2) in the countercurrent direction, the second stage pipeline (P2) and the third stage pipeline (P3) By connecting them in parallel, so that the water vapor flowing through their pipes (P2, P3) is in the countercurrent direction. In addition, by connecting the three-stage pipeline (P3) and the four-stage pipeline (P4) in parallel with each other, the water vapor flowing through their pipeline (P3, P4) stages are directed in the countercurrent direction.

In addition, as can be seen from FIG. 7, in this case, the four stages of the heat exchange pipe 22 (P1, P2, P3, P4) use pipes having the same cross-sectional area (diameter) while the pipes P1, P2, P3 , The cross-sectional area of the two-stage pipeline P2 is made larger than the one-stage pipeline P1 and the cross-sectional area of the three-stage pipeline P3 is larger than the two-stage pipeline P2. The cross-sectional area of the fourth stage pipe P4 is made larger than the third stage pipe P3. More specifically, by multiplying the number of tubes used in the second stage pipeline P2 (two in the example) by the number of tubes used in the first stage pipeline P1 (one in the example), The cross-sectional area twice the cross-sectional area is given to the two-stage pipeline (P2), and the number of tubes used in the three-stage pipeline (P3) (four in the example) is used for the second-stage pipeline (P2) (Figure In the example, the cross-sectional area of twice the cross-sectional area of the two-stage pipe line P2 is given to the three-stage pipe line P3 by doubling the two). Furthermore, the cross-sectional area of the three-stage pipeline (P3) is doubled by doubling the number of tubes (four in the example) used for the four-stage pipeline (P4) to four (four in the diagram). A cross-sectional area of twice the phosphorus is given to the four-stage pipeline P4. Therefore, in the pipelines P1, P2, P3, and P4 partitioned in four stages, their respective cross-sectional areas are doubled each time the number of stages increases. In other words, the cross-sectional areas of the pipelines P1, P2, P3, and P4 partitioned in four stages are proportional to the number of stages.

In this example, the heating zone Z is heated by a heating action by the burner 24 provided on the lower side of the heat exchange pipe line 22, and each of the pipe lines P1, which is formed by four divisions of the heat exchange pipe line 22, is formed. In P2, P3, and P4), the rear end side of the two pipelines of the upper lining is disposed below the front side side. Therefore, the four-stage pipeline P4 corresponding to the final end pipe is arranged below the one-third stage pipelines P1, P2, and P3.

In this case, in the superheated steam generator 20, the pipes P1, P2, P3, and P4 of each stage are connected in a serpentine form, and the pipes P1, P2, P3, and P4 of each stage are arranged up and down. To connect them in a straight line. Compared with FIG. 5, the number of pipe stages is relatively large, and the entire heat exchange pipe line 22 can be arranged in a compact shape.

Experimental results are shown in FIG. 7 in order to prove the operation of the superheated steam generating apparatus 20 described with reference to FIG. 7. In order to obtain this test result, the steam boiler 11 shown in FIG. 4 was used.

In other words, the steam at 110 ° C generated by the steam boiler 11 was introduced into the inlet 21 of the superheated steam generator 20 shown in FIG. The number of pipeline stages of the superheated steam generator 20 is set to five stages, and the arrangement of the pipelines in each stage is set back in accordance with the description with reference to FIG. Stainless steel pipes having a diameter of 15 mm and a length of 450 mm were used for the pipes in each stage, and the pipes at adjacent ends were connected by stainless steel. The number of pipes forming the pipeline of each stage was 1 in 1 stage, 2 in 2 stages, 4 in 3 stages, 8 in 4 stages and 16 in 5 stages. The burner 24 which was operated to form a heating area was used with a hot pot propane gas burner (50000 Kcal). On the other hand, it is also possible to use burner 24 for fueling propane gas burners other than kerosene and heavy oil.

As shown in Figure 8, the water vapor inlet 21 of the water vapor inlet temperature is 110 ℃ 185 ℃ in the first stage pipe (P1), 272 ℃ in the second stage pipe (P2), 405 in the three-stage pipeline (P3) As the number of steps increases, as it says 580 ° C in the four-stage pipeline (P4) and 775 ° C in the five-stage pipeline (P5), the water vapor rises in proportion to about 800 ° C at the outlet 23. . On the other hand, when the steam injection pressure at the steam inlet 21 is set to 0.2 MPa, the pressure in the pipes in each stage of steps 1 to 5 is maintained at a constant value near 0.3 MPa when the steam inlet 23 is open. As a result, the pressure of the vapor airway outlet 23 has never been extremely high as compared to the vapor airway inlet 21.

In this work, it was judged that the pressure resistance performance of the tubular body should be sufficient to predict the pressure resistance performance of 0.3 MPa regardless of the number of steps. In addition, when the ultra-high temperature steam of 775 ° C taken out from the steam outlet 23 is supplied to a pressure vessel for steam at a pressure of 0.1 to 5 MPa and used for the gelatinization step (S10) in the cellulose acetate manufacturing process using corn cob flour as a raw material. In addition, it was confirmed that the superheated steam generator was used as an efficient superheated steam source for the gelatinization process (S10).

[Hot Steam Steam Reactor]

9A is a schematic longitudinal side view of the high temperature steam reactor. The high temperature steam reactor 30 of the same figure is provided with a cartridge 36 of a bucket type in which the reactor body 31 and the piece assembly T are mounted.

The reactor body 31 has a water vapor inlet 33 at the upper part of the body of the vertical length, the drain outlet 34 and the exhaust port 35 is a hollow body at the bottom. In this embodiment, the pressure gauge 322 is provided in the front part. On the other hand, the cartridge 36 is a bucket-type user cylindrical body with a top surface opening in which a cylindrical copper plate 37 is erected around a hole bottom plate 371 having a plurality of water vapor passage holes 372. The cartridge 36 is mounted in the mutual space between the steam inlet 33, the drain outlet 34, and the exhaust port 35 in the reaction tank body 31. A mesh 38 made of stainless steel made of a metal having a ventilation hole smaller than the water vapor passage hole 372 of the hole bottom plate 371 on the inner surface side of the hole bottom plate 371 of the user cylindrical body forming the cartridge 36. Or the mesh is mounted.

Figure 9b is a front view schematically showing the appearance of the high temperature steam reactor. As in the same figure, the reactor body 31 is provided with a lid 32 thereon. The lid 32 is detachable by opening the fastener 371, and the cartridge 36 housed therein can be detached by removing the lid 32.

In the high temperature steam reactor 30 configured as described above, a cartridge 36 equipped with a piece assembly T to be treated by steam is accommodated in the reactor body 31 as shown in FIG. When the high temperature superheated steam is supplied from (33), the superheated water vapor passes through the layer of the piece assembly T, and at the water vapor passage hole 372 of the user cylindrical body hole base plate 371 forming the cartridge 36. I'm going. Then, the water vapor or the liquid residue or gas of the hydrolysis reaction from the water vapor passage hole 372 is recovered through the drain outlet 34 or the exhaust port 35.

The high temperature steam reactor 30 is usually installed in parallel with the condenser and one of the high temperature steam reactor 30 while operating the recovery or replacement of the cartridge 36 in the other high temperature steam reactor 30 In this case, the cartridge 36 of the engraving assembly T is mounted or taken out. The hydrolysis reaction can be continuously operated using a plurality of hot steam tanks.

By adding the net body 38 to the cartridge 36 to prepare for the processing of the small piece aggregate T of the particle size, but the particle size of the pieces of the piece aggregate T is large, the water vapor passage hole of the hole bottom plate 371 ( It is also possible to omit the net body 38 when there is no concern that the situation of the outflow of pieces in 372. By using the above-mentioned high temperature steam reaction apparatus 30, it is possible to take out the fragment aggregate T after the gelatinization process S10 from the reaction tank main body 31 for every cartridge 36, and to perform post-processing.

[Reaction reactor]

10 is a front view schematically showing the appearance of the pyrolysis reaction apparatus 60. The reactor 60 has a cellulose component inlet 611, an inlet 612 of a solid catalyst or a solid acid, an inlet 613 of superheated steam as a heat source, a glacial acetic acid inlet 614, and a drain outlet in the superheated jacket 62. 615, the cellulose acetate outlet 65, the additive inlet 616, and the like, and a stirring blade 64 therein. Since the reaction apparatus 60 is required to be made of a material having excellent acid resistance and strong rigidity, stainless steel, titanium, or the like subjected to corrosion treatment can be suitably employed.

On the other hand, as shown in Figure 3 is connected to the recovery pipe 66 provided in the reaction apparatus 60, the recovery pipe 66 is provided with a recovery device 70 having a condenser 71 in the recovery reaction 66 The acetic acid purified by S30 is condensed through the recovery pipe 66 to be recovered and reused in the recovery device 70.

Table 1 shows the test results of the cellulose acetate prepared by the production method and apparatus of the present invention. Test Items shame unit moisture 2.7 % Acidification 55.1 % 6% viscosity 110 MPaS Calcium oxide 0.03 % An Jung Do 0.06 %

As described above, preferred embodiments of the present invention have been described, but the present invention is not limited to the above-described embodiments, and the present invention belongs to the present invention without departing from the gist of the present invention as claimed in the following claims. Anyone with ordinary knowledge will have the technical spirit of the present invention to the extent that various modifications can be made.

As described above, according to the present invention, it is possible to reduce and suppress the pressure resistance of the pressure vessel used in the gelatinization process by significantly reducing the pressure in the gelatinization process. In the process of initializing the separated cellulose component, there is no need to use a high risk of lactic acid, thereby improving the safety of the manufacturing environment.

Claims (9)

The supernatant steam is applied to the flake aggregates of the wood-based material to which the solid catalyst is added to perform the gelatinization step (S10), and the cellulose component is separated and the purified cellulose component is purified under pressure with a solid acid after the purification step (S20). The cellulose acetate manufacturing method characterized by obtaining the cellulose acetate. The method of claim 1, The gelatinization step (S10) is a method for producing cellulose acetate, characterized in that the superheated steam at 400 to 800 ° C. acts for 15 to 240 min at a pressure of 0.1 to 5 MPa on a piece of wood-based material to which a solid catalyst is added. The method of claim 2, The solid catalyst added to the aggregate of wood-based materials in the gelatinization step (S10) is platinum, titanium oxide, cerium oxide, yttrium oxide, thorium oxide, stone oxide, zinc oxide, manganese oxide, aluminum oxide, silicon oxide, vanadium oxide. It is one kind or plural kinds selectable from the above, The addition amount of the solid catalyst is a manufacturing method of cellulose acetate, characterized in that the dry weight ratio of 1 to 20wt% with respect to the wood-based material. The method according to any one of claims 2 to 3, Particle size of the wood-based material is a manufacturing method of cellulose acetate, characterized in that the diameter of 0.01 ~ 5mm The method of claim 1, The method of producing a cellulose acetate comprising the step of producing a cellulose acetate and acetic acid by adding a glacial acetic acid having a dry weight ratio of 300 to 700 (wt%) with respect to the cellulose component and cellulose. The method of claim 1, The amount of the solid acid added is 1-20 (wt%) by weight based on cellulose, and the solid acid is at least one of synthetic zeolite (zeolite), molten zeolite and clinofuccilol zeolite. Method for producing cellulose. The method of claim 1, The method of producing cellulose acetate, characterized in that the reaction temperature is 70 ~ 130 ℃, the reaction pressure is 0.1 ~ 5MPa, the reaction time is 30 ~ 300min in the initial step (S30). A purifying means (40) consisting of a purifying means (10), a filtration device (41), a dewatering device (42), and a drying device (43) for purifying the treated product, and the purifying means (40). In the manufacturing apparatus (100) comprising a means for superposing the cellulose produced by the reaction; The luxury means 10 is a water vapor inlet 21 connected to the steam engine passage 111 of the steam boiler 11, a heat exchange pipe passage 22 connected to the water vapor inlet 21, and the heat exchange tube 22 A superheated steam generating device (20) comprising a water vapor outlet (23) connected to an end and a burner (24) provided at a lower end of the heat exchange tube (22); The pressure gauge 322 is provided on the lid 32 detachable by the fastener 321 in the upper portion, and the superheated steam inlet 33 is provided below the lid 32 to be connected to the water vapor outlet 23. The reaction body main body 31, which is a hollow body composed of a lower drain outlet 34 and an exhaust port 35 provided on the lower side, and a net body 38 inside the oil hole bottom plate 371 provided with a plurality of water vapor passage holes 372. The hot-plate steam reaction consisting of the cartridge 36 installed in the space between the inlet 33 and the drain outlet 34 and the exhaust port 35 inside the reactor body 31 of the cylindrical copper plate (37) is mounted. Device 30, The initializing means 50 includes a cellulose inlet 611 for injecting the purified cellulose on the reaction tank body 61, a solid catalyst inlet 612 for injecting a solid catalyst or a solid acid, and a recovery pipe 66 ) Is provided, and a steam inlet 613 connected to the water vapor outlet (23), a glacial acetic acid inlet (614) and an additive inlet (616) are provided on the side of the reaction tank body (61) to inject superheated steam as a heat source. A drain outlet 615 and a cellulose acetate outlet 65 are provided below the reaction tank body 61, and the stirring blade 64 rotates by the stirrer 63 inside the reaction tank body 61, and a circumferential direction. A superheat reaction apparatus 60 composed of a superheated jacket 62 formed of; An apparatus for producing cellulose acetate, characterized in that consisting of a recovery device (70) connected to a recovery pipe (66) provided in the nitriding reaction device (60) and provided with a condenser (71) in the recovery pipe (66). The method of claim 8, The heat exchange pipe line 22 is a three-stage first stage pipe (P1), the second stage pipe (P2), the third stage of bureau (P3) between the steam inlet 21 and the steam outlet (23) However, the first stage pipe (P1) and the second stage pipe (P2) is connected in parallel with the multi-stage heating structure connected in parallel with the second stage pipe (P2) and the third stage pipe (P3) Apparatus for producing cellulose acetate, characterized in that the.

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