JPS6038000A - Continuous hydrolytic method and apparatus of cellulose material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for hydrolyzing cellulosic molybdenum. In particular, the present invention relates to a countercurrent process and apparatus for the continuous hydrolysis of cellulosic material I to produce alcohol-enriching sugars.

2. Background Art Various methods have been developed for recovering sugar by hydrolyzing cellulosic materials with acids. The produced T-sucrose can be used for various purposes, such as as a fermentation substrate in the production of alcohol, as an animal Aij 24, or as a raw material for micromanufacturing. Conventional methods for producing sugar by hydrolyzing cellulosic materials with acids include (1) simple cross-section method i2]/(-collesion batch method, (3) co-current continuous method and 4) ノ<-Collesion continuity method 6';).

Although various cellulosic materials have slightly different chemical structures and compositions, they are mainly composed of lignin,
It consists of lignin-bound crystalline cellulose and hemicellulose. Although hemicellulose can be easily separated and hydrolyzed by treatment with mild acids, the remaining lignin-bound cellulose requires much more vigorous treatment for separation and hydrolysis than for one course of hemicells. .

Hydrolysis products of hemicellulose are primarily in the form of pentose sugars (eg xylose, arabinose and ribose) and hexose sugars (eg mannose and galactose).

On the other hand, when crystalline cellulose is hydrolyzed, glucose containing mainly unhydrolyzed lignin is produced in solid form.

The conventional method of recovering sugar by hydrolyzing cellulose-based abrasive materials with acid has had important problems. One major problem is that once the hemicellulose and cellulose in cellulosic materials are hydrolyzed to sugars, acids continue to act on the sugars, breaking them down and producing undesirable waste products. Generally, pentose sugars are first degraded to furfural and then to formic acid and polymeric condensation products, and hexose sugars are initially degraded to hydroxymethylfurfural and then to levulinic acid, formic acid and polymeric condensation products.

The reaction rate of acid hydrolysis proceeds according to the following equation (1).

In formula (1), t represents the elapsed time, ao represents the amount of cellulose present in the cellulose material at time O, and a represents the amount of cellulose remaining at time t. kl represents the first-order reaction rate constant of the cellulose hydrolysis reaction, and e is the base of the natural logarithm system and has a value of about 2.71828.

Once a sugar is formed through a hydrolysis reaction, it immediately undergoes degradation. The decomposition rate of sugar follows the following equation (2).

% formula % (21 In formula (2), t represents the elapsed time, bo represents the amount of sugar present at time 0, b represents the amount of sugar remaining at time t, and k2 represents the amount of sugar remaining at time t. is the first-order rate constant of the decomposition reaction, and e is the base of the natural logarithm system and has a numerical value of approximately 2.71828.

1 and k for both hydrolysis and decomposition rate constants.

For example, for a given temperature and acid concentration, each is fixed. As the temperature or acid concentration increases, so does 2. Importantly, however, the value of the rate constant for hydrolysis increases much more rapidly with increasing temperature and concentration than the value of the rate constant for decomposition. Thus, hydrolysis at a high value of 1 is preferred.

In a typical conventional simple batch process, an amount of cellulosic material is placed in a container and an amount of hot acid is introduced into the kernel container. The acid hydrolyzes the cellulosic material to sugars, quenches the vessel contents, and separates and recovers the sugar solution from residual lignin.

In light of the competitive rates of hydrolysis and decomposition reactions discussed above, the maximum recovery of potentially available sugars in the cellulosic feedstock in the conventional simple batch reaction vessel is approximately 50 to 50%.
It was limited to 5 chi. In industrial processes, the actual recovery is usually much lower. This is because, in the case of a simple batch process, the produced sugar remains in the reaction vessel for the same amount of time as the cellulosic raw material. Thus, although it is necessary to expose cellulosic paulownia wood to hot acid for a substantial period of time to maximize the amount of cellulosic material hydrolyzed by the acid, much of the sugar produced during this time is decomposes, resulting in a low total recovery rate.

In a typical percolation batch process of the prior art, an amount of cellulosic phase material is placed in a container and a hot acid solution is permeated through the container to remove sugar as it is formed. Although the continuous removal of sugar as it forms reduces sugar breakdown, the sugar concentration in a continuously flowing acid solution is relatively low.

Thus, in conventional percolation batch processes, relatively low concentrations of the produced sugar solution must be sacrificed to achieve higher recoveries for total sugar. Low sugar concentration is required for diluted sugar, for example when the sugar solution is used as a substrate in a fermentation process to produce alcohol, e.g. ethanol, or when used as a raw material for the production of molasses. The lengthy time and substantial cost involved in concentrating the solution is highly undesirable.

In a typical co-current continuous process of the prior art, an amount of cellulosic material and an amount of hot acid are mixed together in a continuously flowing stream. The reaction is stopped after a suitable period of time by cooling the mixture or neutralizing the acid, and the resulting sugar solution is separated from the residual lignin solids. Unfortunately, the co-current continuous method suffers from essentially the same problems as the conventional simple batch method. That is, since the residence time of the acid/sugar solution in the reaction vessel is the same as the residence time of the cellulose solids in these methods, the maximum amount of potentially available sugar in the cellulosic material using these methods is Recovery rates were generally no better than those in simple batch methods.

1△I1 to the conventional continuous percolation method
．． −+−1+λLu Xiaofu! Immediately introduce a certain amount of hot acid into the container in a continuous manner. This conventional percolation continuous method is also subject to essentially the same problems as the conventional percolation batch method. That is, since the residence time of the solid cellulosic material is substantially longer than the residence time of the acid solution in such continuous flow systems, removing the sugars as they form eliminates the effective total concentration in the cellulosic material. High recoveries are achieved with sugar. However, these methods unfortunately result in relatively low sugar concentrations in the continuous flowing acid solution.

In an attempt to achieve high total sugar recovery while still maintaining an acceptable sugar concentration in the produced sugar solution, L.C.
Countercurrent hydrolysis processes have been developed, such as that disclosed in U.S. Pat. No. 2,681,871 to L.C. Wallace.

In the Warlace countercurrent hydrolysis process, the cellulosic material and the acid are introduced into a vessel continuously and countercurrently into contact with each other. The resulting sugar solution is continuously withdrawn from one end of the vessel and the remaining lignin solids are withdrawn from the other end. This continuous countercurrent process of Warlace reduces the time and exposes the produced sugars in the vessel to acid, thereby reducing the degree of sugar degradation. Furthermore, continuous introduction of the cellulosic material into the vessel achieved a higher sugar concentration in the produced sugar solution than that achieved with other conventional methods.

Thus, the continuous countercurrent hydrolysis process developed by L. C. Wallace solved some of the problems encountered with conventional methods. Nevertheless, many critical parameters (e.g. recovery of available sugar and sugar concentration of the recovered sugar solution)
could not be maximized using this conventional countercurrent method.

Clearly, it would be desirable to develop a process for hydrolyzing cellulosic materials that recovers the maximum t' of available sugars within the cellulosic material. Furthermore, it is highly desirable to maintain a high sugar concentration in the sugar solution recovered from cellulosic material hydrolysis processes.

Thus, what is needed in the art is a method that combines the advantages of continuous countercurrent flow while optimizing important parameters such as effective sugar recovery and sugar concentration of the recovered sugar solution. It will be seen that the method and apparatus. Such devices and methods are disclosed and claimed herein.

SUMMARY AND OBJECTIVES OF THE INVENTION The present invention relates to a countercurrent method and apparatus for continuously hydrolyzing ri-micellulose materials, and its features i4 Maximum sugar recovery rate and maximum sugar concentration in the recovered sugar solution. be.

The cellulosic material is continuously introduced into the top end of the reaction vessel, while the hot acid solution is continuously introduced into the bottom end of the reaction vessel so as to be in circulating contact with the cellulosic material. The acid solution flowing countercurrently acts on the step 9 that hydrolyzes cellulose (including hemicellulose) in the cellulosic material to produce a sugar C solution and lignin. The sugar solution is continuously removed from the top end of the reaction vessel, and the lignin is continuously removed from the bottom end.

The cellulosic material forms the bed within the reaction vessel;
Its specific density is controlled within a range of about 10 bods/cubic ft to about 30 bods/cubic ft 4).

In one preferred embodiment, the density of the bed is controlled by reducing the particle size of the cellulosic material prior to introducing it into the reaction vessel.

In another preferred embodiment, the specific density of the cellulosic material is controlled by mechanically compressing the cellulosic material forming the bed within the reaction vessel. By increasing the specific density of the cellulosic material, the residence time of the sugar solution within the reaction vessel is decreased. This will be discussed later.

The residence time of the sugar solution produced within the reaction vessel can be further minimized by replacing the volume of liquid contained within the reaction vessel with steam. Such vapor displacement can be accomplished by parging gas into the reaction vessel or by flashing a portion of the hot acid solution within the reaction vessel. Additionally, vapor displacement of the liquid volume within the reaction vessel may be performed in place of or in conjunction with the step of controlling the specific density of the cellulosic material to maximize sugar recovery in this method. good.

Thus, in the apparatus and method of the present invention, the residence time of the forming sugar solution within the reaction vessel is determined by either increasing the specific density of the cellulosic material within the reaction vessel or displacing the liquid volume within the reaction vessel with vapor. or both.

By reducing the residence time of the sugar solution in the reaction vessel, the degree of exposure of the sugar solution to acid is correspondingly minimized,
Decomposition of sugar products is thereby also minimized.

Additionally, maintaining a high bed density requires less space in the reaction vessel, thus allowing the use of smaller 1:9 reaction vessels, as well as equipment that keeps the residence time of the product sugar solution in the reaction vessel to a minimum. It also improves the ability of

Accordingly, one object of the present invention is to provide an improved countercurrent apparatus and method for continuously hydrolyzing cellulosic materials.

Another object of the present invention is to provide a continuous hydrolysis device for cellulose-based materials which recovers the maximum amount of available sugar content of the cellulosic material while maintaining a high concentration in the sugar solution recovered from the process. The purpose is to provide a method.

Yet another object of the present invention is to provide an apparatus and method for the continuous hydrolysis of celluose-based materials in which the size requirements for the reaction vessel are considerably smaller than those used in conventional methods.

Yet another object of the present invention is to provide an apparatus and method for the continuous hydrolysis of cellulosic materials that minimizes the degradation of produced sugars into undesired waste products.

These and other objects and features of the invention will become more fully apparent from the following description and claims taken in conjunction with the accompanying drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention will now be described with reference to the drawings. In the drawings, like parts are designated with like numerals throughout. One preferred embodiment of an apparatus for continuously hydrolyzing cellulosic materials is indicated generally at 10 in the description of FIG.

As shown in FIG. 1, the apparatus 10 includes a feed inlet 20 for receiving cellulosic material into the apparatus.
. Inlet 20 communicates with conventional high pressure feed equipment (not shown), such as extruders, tapered screw feeds, ram feeders, lock hoppers, compression augers, combinations thereof, or any other suitable high pressure feed equipment. ing. A high pressure feeder provides the necessary motive force to move the cellulosic material through the reaction vessel 24.

Supply inlet 2' () is used to feed cellulose feed into reaction vessel 2.
4 under pressure. Two restriction gratings 28 and 34 extend into the container 24. Preferably, restriction gratings 28 and 34 are arranged as shown in FIGS. 1 and 2. As discussed in more detail below, restriction grids 28 and 34 serve to compress the cellulosic material within reaction vessel 24.

The container 24 has a reservoir inlet 30 for injecting the acid solution into the container.
and preferably an outlet 32 for withdrawing the acid solution from the container 24 and recycling the acid solution back to the container 24 via the inlet 30.

An outlet 38 is formed at the bottom end of the reaction vessel 24 to allow lignin to be removed from the vessel 24 and receives lignin from the outlet 38 into the outlet conduit 36.

A pulse valve 37 is provided in the outlet conduit 36 to allow control of the flow of lignin through the conduit.

Another outlet 26 is located at the upper end of the reaction vessel 24 to allow sugar solution to be removed from the vessel 24. exit 26
is provided with a pulp 27 to allow control of the flow of sugar solution through the outlet. Preferably, a conical screen 22 is disposed within the apparatus 10 to pass through the sugar solution before it exits the outlet 26.

The operation of the preferred embodiment illustrated in FIG. 1 and one preferred embodiment of the method for continuously hydrolyzing cellulosic materials is described below. Referring to FIG. 1, the cellulosic raw material to be treated (e.g., corn meal, forestry feed lot) (fee
d lot), grain, municipal waste or industrial waste) is passed through the entire inlet 20 to the device 10.

Then, it is continuously introduced into the reaction vessel 24.

When the cellulosic material enters the reaction vessel 24, a bed (shown) of cellulosic material is formed within the vessel 24. Upon reaching the restricting grid 28, the flow of the cellulosic material slows down substantially so that the cellulosic material becomes compact. Restriction grid 34 further retards the flow of cellulosic material and causes further compaction.

In accordance with the present invention, it will be appreciated that any number of confinement grids may be used to achieve the desired degree of compaction of the cellulosic material. Additionally, the upper limiting grid 28, which acts to compress the cellulosic material, may optionally be
It could also be used alone without the restriction grid 34.

However, currently preferred figures 1 and 2
In the illustrated embodiment, two restriction grids are used.

In this preferred embodiment, the lower restriction grid 34 not only acts to further compress the bed of cellulosic material, but also acts to act as a lower boundary for the bed and to even facilitate the uniform flow of acid through the bed. .

It will be appreciated that arrangements other than those shown in FIGS. 1 and 2 for restriction grids 28 and 34 are possible. In selecting the appropriate design for each grid 28 and 34, factors such as the desired degree of compaction and promotion of uniform flow of acid through the bed of cellulosic material must be considered.

The acid solution flows upwardly toward the outlet 26 at the inlet 30.
The liquid is injected into the reaction vessel 24 through the tube. Sulfuric acid (H2SO4)
Although is the presently preferred acid for use in the present invention, other suitable acids are well known in the art for achieving hydrolysis of cellulosic materials, and thus these too may result in rough and bruising. It will be done. For example, hydrochloric acid (IC), hydrogen fluoride (HF) and phosphoric acid (H, PO,) can also be used.

The upwardly flowing acid solution meets the downwardly flowing cellulosic solution in a countercurrent manner. When the cellulosic material and the acid solution come into contact, the cellulosic material is hydrolyzed to form a sugar solution while the lignin remains as a waste product. The sugar solution is conveyed upwardly through the container 24 together with the acid solution and at the outlet 26 is discharged into the container. Screen 22 filters the sugar solution exiting the vessel and acts as a barrier to the bed of cellulosic material within vessel 24.

If further agitation of the acid solution in reaction vessel 24 is desired, a portion of the acid solution is withdrawn from outlet 32 and added to inlet 3.
0 may be recirculated for subsequent reinjection into container 24. Such recirculation of acid solution serves to provide turbulence in the area where lignin exits vessel 24. Such turbulence is useful in uniformizing the flow of acid upward through the bed of cellulosic material.

Once the cellulosic material is hydrolyzed, the lignin waste product is forced through the restriction grid 34 by the continuous action of the cellulosic material entering the vessel 24. The lignin is then suspended in a turbulent mixing section.

and exits container 24 through outlet 38 and outlet conduit 36.
to go into. The flow of lignin through the outlet conduit 36 can be controlled by passing a pulse valve 37 that opens and closes periodically.

The pressure within the container 24 is raised to a predetermined point and then released by opening the pulse pulp 37.

This pressure release serves to impact or vibrate the bed of cellulosic material within container 24, thus helping to prevent undesirable clogging or obstruction of the container by cellulosic material.

After such pressure release, pulse valve 37 is closed again and pressure is reestablished within vessel 24. The periodic opening and closing of the pulse pulp 37 can be adjusted as desired.

If desired, the acid remaining with the lignin can be separated from the lignin and recycled to the acid port 3o. Additionally, if desired, the lignin can be washed and dried for subsequent use as a fuel or chemical feedstock.

Using the novel apparatus and method of the present invention, maximum recovery of available sugars in cellulosic molybdenum is achieved, and further, the sugar concentration in the recovered sugar solution is also maintained at a relatively high level; Moreover, the amount of sugar decomposed into waste products is also kept to a minimum. As will be explained in detail below, such a result can be achieved by compressing the bed of cellulosic material and/or increasing the residence time of the liquid (and thus the residence time of the sugar solution) within the reaction vessel 24. By minimizing.

can be obtained.

The degree of potential available sugar yield in the cellulosic feedstock depends on the F(It) retention time of the solid cellulosic material in the reaction vessel. This is sufficient to convert almost 100% of the hydrolyzed sugar product into the hydrolyzed sugar product.Of course, the half-life of the hydrolysis reaction depends on various reaction chronicities, such as temperature and acid concentration.The residence time of the solid is It can be defined as:

The sugar concentration in the solid Nagamachi reaction vessel Kanayama sugar solution is mainly determined by the flow ratio (fl) of the solid cellulose material to the liquid acid solution.
ow ratio). A high solid/liquid flow ratio results in a high sugar concentration, whereas a low solid/liquid flow ratio results in a correspondingly low sugar concentration in the resulting sugar solution.

Competing factors to achieve high sugar concentrations in sugar solutions are factors of glycolysis. The residence time of the sugar solution in the reaction vessel determines the decomposers of the sugar in the vessel. When the residence time of the sugar solution in the container is reduced, the amount of degradation is correspondingly reduced. Thus, in order to maintain the full sugar concentration of the recovered sugar solution while minimizing degradation of the sugar solution, the overall solid/liquid flow ratio is maintained at a reasonably high level and the residence time of the sugar solution within the reaction vessel is maintained at a moderately high level. Minimize by reducing the effective volume of liquid sugar solution in the liquid sugar solution.

The residence time of the liquid (sugar (including the container) in the reaction vessel is defined as follows.

In order to maintain the preselected sugar concentration in the produced sugar solution, the fluid flow rate must be maintained at a constant value determined by the selected solids flow rate and sugar recovery. Sugar concentration can thus be defined as:

However, bran weight = solid weight × sugar content in solid × sugar recovery rate
) can be monotonically decreased according to By compressing the solid cellulosic material within the container, the present invention
and a reduction in the liquid volume in the vessel by replacing the liquid in the vessel or reaction vessel with steam.

By quenching the cellulosic material in the reaction vessel, the required volume of the reaction vessel is reduced for a given solids residence time (see Equation (3) in its entirety), thereby reducing the amount of sugar in the reaction vessel at any given time. The volume of the solution decreases. Thus, compacting the bed of cellulosic material within the reaction vessel has the effect of reducing the residence time of the sugar solution within the vessel, thereby minimizing sugar degradation and reducing the required size of the reaction vessel. becomes smaller.

Compression of cellulosic materials by the apparatus and method of the present invention can be accomplished in several ways. As mentioned above, restriction grids 28 and 34 are provided to compress the cellulosic material by restricting the flow of cellulosic phase ρ.

In another preferred embodiment, compaction of the cellulosic material is accomplished by reducing the particle size of the cellulosic material prior to introducing the cellulosic material into the apparatus 10. Particle size reduction occurs as the bed of cellulosic material is compressed by the countercurrently flowing acid solution:
causing a substantial/pressure drop across. In this embodiment, the cellulosic material is first steamed to a first pressure in the range of about 250 bonds per square inch (psi) to about 1500 psi at a temperature in the range of about 200°C to about 320°C for about 1 minute to about Pressure is applied for 30 minutes. The particle size of the cellulosic material is then substantially reduced and the internal structure of the cellulosic material is disrupted by subjecting the pressurized cellulosic material to a second pressure that is substantially low, such as atmospheric pressure. . The degree of particle size reduction depends on pressure conditions and residence time. The degree of particle size reduction under certain pressure and time conditions is shown in Table 1 below.

In the presently most preferred embodiment, the cellulosic material is about 60°C at a temperature in the range of about 250°C to about 270°C.
Steam is applied to a first pressure ranging from 0 psi to about 800 psi for about 1 minute to about 15 minutes, and then subjected to atmospheric pressure. Such particle size reduction methods include e.g.
It is disclosed in US patent application Ser. This patent application is incorporated herein by reference.

A small-scale model of the particle size reduction method in the above patent application uses a cellulosic material (in this case, sawdust) last steam of approximately 4.
Apply pressure Lf to a pressure of 00 to 800 psi for approximately 1 to 10 minutes.
This is done by subjecting the cellulosic material to atmospheric air. The particle size distribution of the product obtained is shown in Table 1 below.

(For comparison, the particle size distribution of untreated sawdust is also
Shown in the table. ) It will be appreciated that other means of compressing cellulosic monthly yields are possible in accordance with the present invention.

For example, pond limits 4 other than limit grids 2-8 and 34.
A reactor can be placed within the reactor to restrict the flow of cellulosic material within the reaction vessel, thus achieving compaction of the cellulosic material.

Using one or more of the above embodiments, alone or in combination, for total compaction of cellulosic materials according to the invention;
It should be appreciated that it is also possible to achieve the compacted density required for cellulosic mass production within the reaction vessel.

One important controlling factor in the present invention is thus the compaction density of the cellulosic molybdenum. In the novel apparatus and method of the present invention, the bed density of cellulosic material within the reaction vessel is from about 10 bonds/cubic phyto to about 30 pounds/cubic filtrate to achieve the aforementioned preferred results.
It has been found that it is necessary to control the temperature within the range of bθ/ft8).

As mentioned above, minimizing the residence time of the liquid can be achieved not only by compression, but also by vapor displacement of the liquid within the reaction vessel. When the liquid in the reaction vessel is replaced with vapor, the effective liquid volume in the vessel decreases l2, thereby shortening the residence time of the liquid, thus producing an effect similar to cellulosic monthly rate compression. Such steam displacement is
(1) Expanding, or sparging, an inert gas (e.g., carbon dioxide) into the liquid in the reaction vessel.
(2) flushing away a portion of the hot liquid within the reaction vessel.

In one presently preferred embodiment, carbon dioxide gas is expanded from the acid port 30 or acid port 1'' 32 into the reaction vessel 24 at a gas/liquid volume ratio ranging from about 0.1:1 to about 20:1. . The carbon dioxide gas recovered along with the sugar solution from outlet 26 is optionally transferred to inlet 30 or outlet 3.
2 and may be recycled back.

When vapor displacement is accomplished by flushing a portion of the hot acid solution (including the sugar solution) within the reaction vessel, flushing is accomplished by controlling the pressure within the reaction vessel. In this embodiment, the hot acid aqueous solution in reaction vessel 24 is directed to a flash point of the acid solution.
oint; ) and then exposed to a pressure at which bubbles begin to form in the reaction vessel.

In the presently preferred embodiment of FIG. 1, this flushing reduces the pressure within the reaction vessel sufficiently below the flash point of the hot acid solution to produce a temperature drop in the acid solution of about 0.5°C to about 20°C. Valve 27 and 3
This is achieved by adjusting 7. Such flushing involves a ratio of about 01=1 to about 10:1 of the reaction vessel air/
Provides a liquid flow-to-volume ratio.

It has been found that the steam displacement method of the present invention is most effective for relatively low density cellulosic beds. This is because a dense bed contains very little liquid available for vapor displacement. In the case of a dense bed, most of the liquid in the reaction vessel is retained by capillary action of the cellulosic solution. On the other hand, in the case of a bed of low density, such capillary action is less strong and the liquid can therefore be more easily replaced by vapor.

Once again, in the present invention the residence time of the liquid can be reduced by either compaction of the bed of cellulosic material or vapor displacement of the liquid within the reaction vessel, or both.

Other preferred reaction conditions for achieving the desired results previously contemplated by the present invention are generally as follows, although the exact preferred reaction conditions will depend on variables such as the nature of the cellulosic feed paulownia wood being treated. be. The temperature within the reaction vessel should preferably be maintained in the range of about 170°C to about 260°C. Currently the preferred range is about 22
0°C to about 240°C.

The acid to be used is any suitable acid used for hydrolysis, with sulfuric acid being the currently preferred hydrolysis acid. The acid concentration ranges from about 0.001% to about 10% by weight.
You should call the weight staff. The currently preferred range is about 0.05
The acid concentration ranges from 11 U parts to about 0.3 parts by weight.

Under these conditions, for reaction (1), the value is about 0.04 to about 3, with a preferred range of about 0.1 to about 2. Under these reaction conditions, the corresponding k of reaction (2).

The value is about 005 to about 1, and under the presently preferred reaction conditions disclosed herein, about 007 to about 075.

Under these reaction conditions, the half-life of this hydrolysis reaction is about 17.3 minutes to about 0.23 minutes (under currently preferred reaction conditions, about 6.9 minutes to about 0.35 minutes).
However, on the other hand, the half-life of the decomposition reaction ranges from about 139 minutes to about 0.
69 minutes (approximately 9.9 minutes under currently preferred reaction conditions)
minutes to approximately 0.92 minutes). Furthermore, at these preferred reaction conditions, reactors smaller than those currently used in the art can be used in conjunction with the novel apparatus and methods of the present invention.

The exact volume of the reaction vessel of the present invention depends on the desired feed rate of solid cellulosic material, the bed density of the cellulosic material within the reaction vessel, and the value of . As an example,
If it is desired to process 1 dry ton of sawdust per hour, and if a compaction weight of 101 bS/ft3 is maintained in the bed of cellulosic material, and a value of 1 in 004 is used, then approximately 151 cubic ton of sawdust per hour is desired. A reaction vessel with a volume of 3 feet (ft3) will be required. Bed density is 20 lbs/
ft'' and the value is increased to 30, approximately 0.81 ft3 of reactor volume would be required to process the same amount of soybean and waste.

The solid/liquid flow ratio maintained within the reaction vessel is determined primarily by the desired degree of fermentable sugar in the acid solution removed from the reaction vessel. As an example, if it is desired to achieve a fermentable sugar concentration of 14 hours in the acid solution (before flash cooling), then the solid/liquid flow rate will be about 1:28, or about 0 for each bond 7 minutes of acid. This would be .35 pounds per minute (lbs/min). To achieve a fermentable sugar concentration of 8% in the acid solution, about 1=57, or about 0.181 bs/min of sawdust for each bond 7 min of acid would be required.

A computer model of the countercurrent acid hydrolysis process of the present invention was developed to anticipate the benefits of cellulosic paulownia bed compaction and vapor displacement of liquid in the reaction vessel. With this model, a sugar concentration with an expected recovery of total available sugars of 8.8% was calculated.

The expected sugar recoveries for various compaction densities using various reaction vessel volumes are shown in Table 1 below.

Table n 10 2.88 69.7 69.6 8.81.5
1.92 81.28], 2 8.820 1.44
86.886.7 8.825 1.15 90.1
90.1 What should be noted in 8.8 is that the present invention includes J, 9
Sugar recoveries of about 70-90% were obtained using cellulosic paulownia wood in-bed compaction densities of 10-25 bonds/cubic foot.

The effect of vapor displacement in a reaction vessel having a bed with a compressed density of 10-J, bs/ft' was similarly determined using a computer-implemented model. The results of this computerized model are shown in Table 1 of the Pope.

Table 1 0% 2.88 69.7 69.6 8.810%
2.88 72.6 72.3 8.815% 2.8
8 73.7 73.7 8.920% 2.88 7
5.5 75.4 8.8 As can be seen from Table 1 above, for this computerized model, when 20% of the reaction vessel volume is replaced with steam according to the present invention, the sugar recovery rate is slightly less than a factor of 70. It was expected that there would be an increase from 75 to f-shift, which is slightly larger than 75.

From the above, it can be concluded that the method and apparatus of the present invention can be used in alcohol production processes. In such a process, there are actually two cellulosic feedstocks, such as corn or corn, and an aqueous phase.
stry), feedlotsl-(feed], ot)
, cereals, urban and yet still industrial waste can be used. The cellulosic feedstock is comminuted if necessary and processed by the continuous cellulosic material hydrolysis method and apparatus of the present invention. The sugar solution recovered from the hydrolysis process can then be converted to alcohol by any suitable method, such as those described below.

The sugar solution is first diluted with a base, such as sodium hydroxide, calcium hydroxide or any other suitable base, typically 1 d.
Neutralize to pH about 45-60. This slightly acidic slurry is typically referred to as "wort".

The temperature at which the wort is suitable for fermentation, typically around 30-32
When it cools down to ℃, add yeast] and fungal nutrients to the wort.

Once cooled, immediately introduce it into the fermentation vessel containing the wort i yeast. Yeast eats the sugar in Uwa-1 and produces ethanol and carbon dioxide as byproducts. All the carbon dioxide gas is removed 7, while the ethanol remains in solution. In a typical fermentation process,
Ethanol and carbon dioxide are about 51% and 49% respectively
produced in a relative yield of

Once fermentation is complete, the spent wort containing ethanol is sent to a distillation column for separation of total ethanol. Ethanol, which has a lower boiling point than water, is separated from the consumed wort in a distillation column,
This can be purified to the desired degree.

From the above description, the present invention provides cellulose-based products such as
It will be appreciated that the present invention provides an improved countercurrent apparatus and method for the continuous hydrolysis of sugars that can be used in the production of alcohols such as ethanol. Furthermore, the present invention provides cellulose that recovers the great potential of effective sugar impregnation of cellulosic paulownia wood while maintaining a high sugar concentration in the recovered sugar solution and minimizing the decomposition of the produced sugar. An apparatus and method for continuous hydrolysis of paulownia wood are provided.

The present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Accordingly, the embodiments described above should be considered in all respects merely illustrative and not limiting. The scope of the invention is, therefore, indicated by the following claims, and not by the following description. It is intended that the claims encompass all changes that come within the meaning and range of equivalency.

[Brief explanation of the drawing]

FIG. 1 shows a part 1 of the presently preferred embodiment of the continuous hydrolysis apparatus and method for cellulosic paulownia wood according to the present invention.
2 is a plan view of the preferred embodiment of the restriction grid shown in FIG. 1; FIG. 20... Inlet for cellulosic substance supply, 22... Screen, 24... Reaction vessel, 26 Outlet for sugar solution removal, 28. 34... Limiting grid, 30... Inlet for acid solution introduction, 32 ...Amount of acid solution extracted], 38...Lignin extraction outlet, continued from page 1 Priority claim [Phase] 198 Hu April 7 [Phase] United States (U.S.
) [Phase] 511783 @ Inventor James H.
United States Yu Reynolds L 589

Claims (1)

Claims: (1) a cellulosic material is continuously introduced into a first end of the reaction vessel to form a bed within the reaction vessel; the density of the cellulosic bed is approximately 10 pounds/cubic; An acid solution is continuously introduced into the second end of the reaction vessel to a range of about 30 bonds/cu. contacting the acid solution with the cellulosic material in a countercurrent manner to produce lignin; removing the sugar solution from a first end of the reaction vessel; and removing lignin from a second end of the reaction vessel. Continuous hydrolysis method for cellulose materials. (2) The density of the bed is controlled by reducing the particle size of at least a portion of the cellulosic material prior to introduction of the cellulosic material into the reaction vessel. Continuous method. (3) pressurizing the cellulosic material with steam to a first pressure in the range of about 250 psi to about 1500 psi for about 1 minute to about 30 minutes; and subjecting the cellulosic material to a second pressure of substantially reduced pressure; A continuous method according to claim 2, characterized in that the particle size of at least a portion of the cellulosic material is characterized by a steam fragmentation process comprising the step of fracturing the structure of at least a portion of the cellulosic material. (4) Claim No. 2, wherein the second pressure is atmospheric pressure
Continuous method described in section 3). (Approximately 60% with 51se/I/loin type 1'f4'e steam)
3. The continuous process of claim 3, wherein the first pressure is applied to a pressure in the range of 0 psi to about 800 psi for about 1 minute to about 15 minutes. (6) The continuous method according to claim (1), wherein the specific density is controlled by compressing the cellulosic material forming the bed. (7) A continuous method according to claim (6), in which the cellulosic material is compressed with a grid installed in the reaction vessel. (8) The continuous method according to claim (1), further comprising the step of controlling the volume of the acid solution in the reaction vessel by replacing part of it with gas. (9) Continuously introducing the cellulosic material into the first end of the reaction vessel; continuously introducing the acid solution into the second end of the reaction vessel, and the acid solution hydrolyzing the cellulosic material to form sugars; The solution is contacted with the cellulosic material in a countercurrent manner to produce lignin; the volume of the acid solution in the reaction vessel is controlled by displacing a portion of it with gas; the sugar solution is placed at the first end of the reaction vessel. A process for continuous hydrolysis of cellulosic materials, comprising the steps of: and removing the lignin from a second end of the reaction vessel. 10. The continuous process of claim 9, wherein the +IO1 acid solution volume control step comprises expanding a gas into the acid solution to displace a portion of the acid solution in the reaction vessel. 11. The continuous process of claim 10, wherein sufficient gas is expanded into the acid solution such that the gas to acid solution volume ratio is from about 001:'1 to about 20:1. (121) The continuous method according to claim 101, wherein the gas expanded into the acid solution comprises carbon dioxide. (13) The step of controlling the volume of the acid solution flushes out a portion of the acid solution to form vapor. , thereby displacing a portion of the acid solution in the reaction vessel.
1. The continuous method according to claim 1. Q9: The continuous method according to claim (1) or (9), wherein the temperature in the reaction vessel is in the range of about 170°C to about 260°C. (t6) The continuous process according to claim 1 or 9, wherein the acid solution has an acid concentration of about 0.001% by weight to about 10% by weight. Claim No. (1) in which the acid in the αD acid solution is sulfuric acid
Continuous method as described in paragraph or paragraph (9). 08 Claim 1 further comprising the steps of: putting the sugar solution into a fermentation vessel; mixing yeast with the sugar solution; fermenting the sugar solution to produce alcohol; and distilling the alcohol in a distillation column. ) or the continuous method described in paragraph (9). 09 Reaction vessel; a first inlet means located at a first end of the reaction vessel for receiving cellulosic material into the reaction vessel; from about 10 pounds/cubic foot to about 30 pounds/cubic cellulose-based material; means for compressing the sugar solution to a density in the range of fibers; second artificial means disposed at the second end of the reaction vessel for receiving the acid solution into the reaction vessel; and for removing the sugar solution from the reaction vessel. a first outlet means located at a first end of the reaction vessel for removing lignin from the reaction vessel; and a second outlet means located at a second end of the reaction vessel for removing lignin from the reaction vessel. A continuous hydrolysis device for cellulosic materials, characterized by comprising: 20. The apparatus of claim 9, wherein the compression means comprises a grid mounted within the reaction vessel between the first population means and the second outlet means. (21) The apparatus of claim 20, further comprising a second grid mounted within the reaction vessel for further compressing the cellulosic material. The apparatus of claim 19 comprising means for reducing the particle size of at least a portion of the cellulosic material prior to introduction into the reaction vessel. (23) Displacing a portion of the acid solution in the reaction vessel. Claim No. 1 (including means for controlling the volume of nucleic acid solution)
The device according to item 19. (241 reaction vessel: a first inlet means located at a first end of the reaction vessel for receiving cellulosic material into the reaction vessel; a first inlet means of the reaction vessel for receiving an acid solution into the reaction vessel; a second inlet means located at the second end; a first outlet means located at the first end of the reaction vessel for removing a sugar solution from the reaction vessel; a second outlet means disposed at a second end of the reaction vessel for removal; and means for partially displacing the acid solution in the reaction vessel to control the volume of the acid solution. An apparatus for continuous hydrolysis of cellulosic materials, characterized in that: (25) the apparatus according to claim 1241, wherein the means for displacing the acid solution comprises means for expanding gas into the reaction vessel; (26) the apparatus for continuously hydrolyzing cellulosic materials An apparatus according to claim 04j, wherein the displacement means comprises means for flushing a portion of the acid solution within the reaction vessel to form a vapor within the reaction vessel. The apparatus according to claim 6), further comprising means for controlling the degree of flushing of the acid M solution. c!8) Receiving the sugar solution from the first outlet means of the reaction vessel and fermenting it. Claims (1, 9) or Q.
b) 1s promotion as described in 1j1.