TWI384073B - Method for producing bioethanol from fiber product containing cellulose - Google Patents

Description

Method for producing quality alcohol by using cellulose-containing fiber products as raw materials

This invention relates to a process for producing bioethanol, and more particularly to a process for producing a quality alcohol from a cellulose-containing fiber product.

With the development of technology and economy, the demand for energy in human society is increasing day by day. However, the energy currently relied on, such as oil, natural gas or coal, is a polluting energy source. Excessive use will lead to shortages in addition to pollution and environmental damage. . Therefore, pollution-free and renewable energy sources are receiving more and more attention.

The so-called renewable energy refers to the natural energy that can theoretically be inexhaustible, such as solar energy, wind energy, hydropower, geothermal energy or biomass energy. Among them, the use of biomass energy is a very important and popular topic in recent years. The so-called biomass energy refers to the extraction of organic matter (that is, biomass) produced by diverse organisms. After being transformed by various natural or artificial chemical reactions, it can be directly or indirectly used as an energy user. In short, biomass can be regarded as an important green energy source because it is a biologically produced organic substance as an energy source, so it is non-toxic and decomposable.

In general, the utilization of biomass energy is a sugar fermentation method that converts biomass into alcohol. The first generation of raw alcohol was produced from food crops such as grains and sucrose, which had the disadvantage of causing energy consumption and competing with food demand. The second generation of raw alcohol is produced by using fibrous waste agricultural waste such as rice straw, corn stalk, bagasse or sawdust, so it is also called fiber alcohol, which makes full use of agricultural waste and non-food energy crops, but The disadvantage is that the pre-processing is more complicated and time-consuming, and the recovery rate is not high.

In practice, how to properly use cellulose-containing fiber products can further simplify the process, reduce the difficulty of cellulose extraction and separation, and improve the yield or recovery rate of the final product. This is the current production technology of cellulose bio-alcohol. The subject to be overcome.

The present invention provides a method for producing a quality alcohol by using a cellulose-containing fibrous product as a raw material, which extracts cellulose in a raw material with an acidic solution, and then precipitates the cellulose by a non-solvent.

The present invention provides a method for producing a quality alcohol from a cellulose-containing fibrous product, which comprises the following steps. First, a cellulose-containing fibrous product is dissolved in an acidic solution. Next, a first filtration process is performed to obtain a filtrate containing cellulose. Further, a non-solvent is added to the filtrate to precipitate cellulose in the filtrate. Next, a second filtration process is performed to obtain the precipitated cellulose. Finally, an enzymatic hydrolysis and fermentation process is carried out to convert the cellulose into sugar and alcohol.

In an embodiment of the invention, the cellulose-containing fibrous article comprises a cotton-containing article or paper.

In one embodiment of the invention, the cotton-containing article comprises a textile, a non-woven fabric or a yarn.

In one embodiment of the invention, the cellulose-containing fibrous article is a waste cellulose-containing fibrous article.

In an embodiment of the invention, the acidic solution comprises a Phosphoric Acid solution, a Sulfuric Acid solution or a Hydrochloric Acid solution.

In an embodiment of the invention, the above-mentioned acidic solution has a concentration by weight of 30 to 90%.

In an embodiment of the present invention, the step of dissolving the cellulose-containing fibrous product in an acidic solution is carried out at a temperature of 50 to 90 ° C for 10 minutes to 3 hours.

In one embodiment of the invention, the non-solvent described above comprises water or acetone (Acetone).

In one embodiment of the present invention, the ratio of the amount of the non-solvent used to the amount of the acidic solution used is from 0.1:1 to 10:1.

In an embodiment of the invention, the method for producing a quality alcohol by using the cellulose-containing fiber product as a raw material, further comprising the step of recovering polyester (PET) after performing the first filtering process.

In an embodiment of the present invention, the method for producing a quality alcohol by using the cellulose-containing fibrous product as a raw material, further comprising the step of recovering the non-solvent after performing the second filtering step.

In one embodiment of the present invention, the method for producing a quality alcohol by using a cellulose-containing fibrous product as described above, wherein after performing the second filtration process to obtain the precipitated cellulose, further comprises performing a washing procedure.

In one embodiment of the present invention, the enzyme used in the enzyme hydrolysis and fermentation process includes an endo-type fibrinolytic enzyme, an exo-type fibrinolytic enzyme, and a cellobiose or cellooligosaccharide hydrolase.

In one embodiment of the present invention, the above method for producing a quality alcohol using a cellulose-containing fibrous product as a raw material does not perform a high-temperature sterilization process before the enzyme hydrolysis and fermentation process.

Based on the above, the method for producing a quality alcohol according to the present invention is to use a cellulose-containing fibrous product as a raw material, to simultaneously pretreat the raw material with an acidic solution, and to dissolve the cellulose component, and then add the non-solvent which cannot dissolve the cellulose to the fiber. The protein is saturated and precipitated. Therefore, the method of the present invention can extract and decompose cellulose in the raw material as compared with the conventional method, which is simpler and does not require a specially selected strain.

The above described features and advantages of the present invention will be more apparent from the following description.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a flow chart showing a method for producing a quality alcohol from a cellulose-containing fibrous product according to an embodiment of the present invention. Please refer to FIG. 1, which includes the following steps. First, in step 110, a cellulose-containing fibrous product is dissolved in an acidic solution. The above cellulose-containing fibrous product is, for example, a cotton-containing product, paper or other suitable cellulose-containing material, wherein the cotton-containing product is, for example, a textile, a nonwoven fabric or a yarn. In the present embodiment, the cellulose-containing fibrous product is a waste cellulose-containing fibrous product such as recycled paper, recycled old clothes, discarded cloth or yarn.

Since cellulose has an alkali-resistant and acid-resistant property, cellulose is dissolved in an acid solution under appropriate acid treatment. In the present embodiment, the acidic solution is, for example, a phosphoric acid solution, a sulfuric acid solution, a hydrochloric acid solution, a nitric acid solution or other suitable acidic solution, and the concentration by weight is approximately between 30 and 90%. The above acidic solution is an 85% phosphoric acid solution from the viewpoint of industrially common and readily available. Further, this dissolution step 110 is carried out at a temperature of 50 to 90 degrees Celsius for 10 minutes to 3 hours.

It is to be noted that the present invention does not particularly limit the kind of the above acidic solution, the concentration by weight, the temperature conditions for dissolution, and the progress time. In other words, the same or similar performance may be present under different acidic solution types, weight percentage concentrations, temperature conditions, and time of conduct, and those having ordinary knowledge in the art may appropriately adjust themselves according to the desired result.

2 is an experimental result of the effect of pretreatment of phosphoric acid and the presence or absence of decoloration on hydrolysis of cellulose according to an embodiment of the present invention. Fig. 3 is a graph showing the results of an experiment for inhibiting the dyeing of sugar into alcohol by an example of the dye and the decolorization of the present invention. In order to clarify whether the cellulose-containing fibrous product used in the present example was dyed, whether it had an effect on the phosphoric acid hydrolysis effect, the following experiment was conducted. Please refer to Figure 2 first, and combine the data of three sets of experiments of treating waste cotton cloth, decolorized waste cloth and colored waste cloth with phosphoric acid, and data of three sets of experiments without using phosphoric acid treated waste cotton cloth, decolorized waste cloth and colored waste cloth. Comparison. In Fig. 2, the horizontal axis represents time, and the vertical axis represents sugar concentration, and the higher the sugar concentration, the better the hydrolysis effect. It can be clearly seen from the results in Fig. 2 that the hydrolysis effect by the phosphoric acid solution pretreatment is obviously better than that of the un-phosphoric acid alone, and the effect of using waste cotton cloth as a raw material is slightly higher than that of the decolorized waste cloth and the colored Waste cloth. Next, referring to Fig. 3, in Fig. 3, the horizontal axis represents time, the vertical axis represents sugar concentration, and the lower the sugar concentration with time, the better the fermentation effect. As is clear from the results of Fig. 3, the dye and the treatment of decolorization in this example have no significant inhibition on the sugar fermentation.

Referring again to FIG. 1, then, in step 120, a first filtration process is performed to obtain a filtrate containing cellulose. After the completion of the step 110, the cellulose contained in the fibrous product is dissolved in the acidic solution, and at this time, a filtration procedure is carried out to separate the cellulose-containing filtrate and other components insoluble in the acidic solution. The foregoing filtration method may be general screen filtration, filter paper filtration, centrifugal filtration or other possible filtration methods, and those skilled in the art may appropriately adjust themselves.

In this embodiment, after performing the first filtering process, a step 160 of recovering polyester (PET) is further included. Polyester is a common raw material of man-made fiber. It can be made into polyester yarn separately, or it can be blended with natural fibers such as cotton, hemp and wool to make a textile. The use of polyester has become very common in the modern textile and ready-to-wear industry. Since the polyester has acid and alkali resistance characteristics, after the acid treatment in the dissolution step 110 described above, the cellulose dissolved in the acid solution is collected together with the filtrate, and the remaining components contain the acid-insoluble aggregate. Ester component. These polyester-containing mixtures can be further processed to improve the overall utilization of the cellulose-containing raw materials.

Further, in step 130, a non-solvent is added to the filtrate to precipitate the cellulose in the filtrate. The filtrate collected in step 120 contains cellulose dissolved in the acid solution, so a solution which is insoluble to cellulose, that is, a non-solvent as described herein, is added to supersaturate the cellulose in the solution (precipitation). Precipitate. In the present embodiment, the non-solvent is, for example, water, acetone or other suitable solution, and the ratio of the amount of the non-solvent used to the amount of the acidic solution used is from 0.1:1 to 10:1. It is to be noted that the present invention does not particularly limit the ratio of the amount of the non-solvent used to the amount of the acidic solution used in the range of 0.1:1 to 10:1. In other words, under other ratios, it is also possible to have the same or similar cellulose precipitation performance, and those skilled in the art can appropriately adjust themselves.

Thereafter, in step 140, a second filtration process is performed to obtain the cellulose precipitated in step 130. The cellulose precipitated in step 130 can be obtained by conventional screen filtration, filter paper filtration, centrifugal filtration or other possible filtration methods. In this embodiment, the cellulose precipitated after filtration may further comprise performing a washing procedure 170, and the washed solution may be distilled water.

After the second filtration process 140 is performed, a step 180 of recovering the non-solvent may be further performed. If the non-solvent used in the above step 130 is acetone or other solution, it can be used in step 130 after recovery.

Finally, step 150 is performed to perform an enzyme hydrolysis and fermentation process to convert the cellulose into sugar and alcohol. In the present embodiment, the enzyme used in the enzyme hydrolysis and fermentation process includes an endo-type fibrinolytic enzyme (for example, endo-β-1, 4 glucanase) and an exo-type fibrinolytic enzyme (for example, exo-β- 1,4 glucanase) and a cellobiose or cellooligosaccharide hydrolase (for example, β-glucosidase). The endo-type fibrinolytic enzyme mainly acts on the amorphous region of cellulose, and decomposes the β-1,4 glucosidic bond of cellulose in a random manner. The external action of the exo-type fibrinolytic enzyme starts from the non-reducing end of the crystalline region of cellulose and is decomposed in units of cell disaccharide to produce a cell disaccharide. The cellooligosaccharide hydrolase hydrolyzes cellobiose or cellooligosaccharide to glucose from the non-reducing end.

Figure 4 shows the experimental results of the effects of phosphoric acid pretreatment, cellulose source and dyeing, and decolorization on enzyme hydrolysis. Referring to Fig. 4, in Fig. 4, the horizontal axis represents time, and the vertical axis represents sugar concentration, and the higher the sugar concentration, the better the enzyme hydrolysis effect. Phosphoric acid treated cotton, waste cotton cloth, dyed waste cloth, decolorized waste cloth, blended waste cloth and decolorized blended waste cloth, and non-phosphoric acid treated cotton, waste cotton cloth, dyed waste cloth, decolorized waste cloth, blended waste The enzyme hydrolysis test data of the cloth and the decolorized blend waste cloth were compared and compared. It can be clearly seen from the results of FIG. 4 that the hydrolysis effect of the phosphoric acid solution added in this embodiment is obviously better than that of the simple hydrolysis without the addition of phosphoric acid, and the effect of using cotton or scouring cloth as a raw material is higher than that of the color cotton cloth and the bleaching cloth. , color blended fabric and bleaching cloth, but the difference is not big, and it can be hydrolyzed completely within 5~10 hours, generally lignocellulose takes 1.5~2 days.

It is worth mentioning that in this embodiment, the high temperature sterilization process is not performed until the enzyme hydrolysis and fermentation process. Due to the high temperature sterilization of glucose and nitrogen source, the Maillard reaction is caused, so that part of the glucose is not metabolized by the bacteria, thus affecting the recovery rate of the final product alcohol. 5A and 5B are experimental results of direct synchronous fermentation of waste cotton cloth and dyed waste cotton cloth without high temperature sterilization. Referring to FIGS. 5A and 5B, in FIGS. 5A and 5B, the horizontal axis represents time and the vertical axis represents alcohol production. As is clear from the results of Fig. 5A, the undyed waste cotton cloth had an alcohol yield of about 43.4 g/L and a conversion of 0.42 g EtOH/g glucose. As is clear from the results of Fig. 5B, the dyed waste cotton cloth had an alcohol yield of about 47.7 g/L and a conversion rate of 0.43 g EtOH/g glucose.

In addition, the following test data for providing high temperature sterilization treatment and non-high temperature sterilization treatment before fermentation are shown in Table 1. It can be clearly seen from the same reference to Figs. 5A, 5B and Table 1 that high alcohol conversion rate can be obtained without high temperature sterilization treatment before fermentation.

In summary, the method for producing a quality alcohol by using a cellulose-containing fiber product as a raw material is to dissolve the cellulose component by an acidic solution, and because the cellulose in the fiber product does not contain lignin and other sugars. Class, so its alcohol production rate is faster, and the conversion rate is higher. Secondly, the cellulose component does not need to be sterilized after being dissolved and extracted, in addition to reducing the working time, and further improving the recovery rate of the final product (alcohol). In addition, the polyester can be separated and recovered while filtering and extracting the cellulose component, so that the raw material can be further recycled.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the invention, and any one of ordinary skill in the art can make some modifications and refinements without departing from the spirit and scope of the invention. The scope of the invention is defined by the scope of the appended claims.

110. . . Dissolving a cellulose-containing fibrous product in an acidic solution

120. . . Performing a first filtration process to obtain a filtrate containing cellulose

130. . . Adding a non-solvent to precipitate cellulose in the filtrate

140. . . Perform a second filtration process to obtain precipitated cellulose

150. . . Perform an enzyme hydrolysis and fermentation process to convert cellulose into sugar and alcohol

160. . . Carry out a step of recycling the polyester

170. . . Carrying out a cellulose washing procedure

180. . . Carry out a step of recovering the acidic solution and the non-solvent

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a flow chart showing a method for producing a quality alcohol by using a cellulose-containing fibrous product as a raw material.

2 is an experimental result of the effects of phosphoric acid pretreatment and dyeing according to an embodiment of the present invention.

Figure 3 is a graph showing the results of experiments on the inhibition of dyeing and decolorization of sugars into alcohol by an embodiment of the present invention.

4 is an experimental result of the effect of pre-treatment of phosphoric acid, cellulose source and dyeing on hydrolysis of an enzyme according to an embodiment of the present invention.

5A and 5B are experimental results of direct synchronous fermentation of waste cotton cloth and dyed waste cotton cloth without high temperature sterilization.

110. . . Dissolving a cellulose-containing fibrous product in an acidic solution

120. . . Performing a first filtration process to obtain a filtrate containing cellulose

130. . . Adding a non-solvent to precipitate cellulose in the filtrate

140. . . Perform a second filtration process to obtain precipitated cellulose

150. . . Perform an enzyme hydrolysis and fermentation process to convert cellulose into sugar and alcohol

160. . . Carry out a step of recycling the polyester

170. . . Carrying out a cellulose washing procedure

180. . . Carry out a step of recovering the acidic solution and the non-solvent

Claims (11)

A method for producing a quality alcohol by using a cellulose-containing fibrous product, comprising: dissolving a cellulose-containing fibrous product in an acidic solution, wherein the cellulose-containing fibrous product comprises a cotton-containing product or paper, Or a waste cellulose-containing fibrous product; performing a first filtration process to obtain a filtrate containing cellulose; and after performing the first filtration process, further comprising the step of recovering the polyester; Adding a non-solvent to the filtrate to precipitate cellulose in the filtrate; performing a second filtration process to obtain precipitated cellulose; and performing an enzyme hydrolysis and fermentation process to convert the cellulose into sugar And alcohol. The method for producing a quality alcohol by using a cellulose-containing fibrous product as described in claim 1, wherein the cotton-containing product comprises a textile, a non-woven fabric or a yarn. The method for producing a quality alcohol by using a cellulose-containing fibrous product as described in claim 1, wherein the acidic solution comprises a phosphoric acid solution, a sulfuric acid solution or a hydrochloric acid solution. A method for producing a quality alcohol by using a cellulose-containing fibrous product as described in claim 3, wherein the concentration of the acidic solution is 30 to 90 wt%. The method for producing a quality alcohol by using a cellulose-containing fibrous product as described in claim 1, wherein the step of dissolving the cellulose-containing fibrous product in the acidic solution is at 50 to 90 degrees Celsius. The temperature is carried out for 10 minutes to 3 hours. A method for producing a quality alcohol by using a cellulose-containing fibrous product as described in claim 1, wherein the non-solvent comprises water or acetone. The method for producing a quality alcohol by using a cellulose-containing fiber product as described in claim 1, wherein the ratio of the non-solvent used to the acidic solution is 0.1:1 to 10:1. The method for producing a quality alcohol by using a cellulose-containing fibrous product as described in claim 1, wherein after the second filtering step, the step of recovering the non-solvent is further included. The method for producing a quality alcohol by using a cellulose-containing fibrous product as described in claim 1, wherein after performing the second filtration process to obtain precipitated cellulose, a washing process is further included. The method for producing a quality alcohol by using a cellulose-containing fiber product as described in claim 1, wherein the enzyme used in the enzyme hydrolysis process comprises an endo-type fibrinolytic enzyme and an exo-type fiber decomposition. Enzyme and a cellobiose or cellooligosaccharide hydrolase. A method for producing a quality alcohol by using a cellulose-containing fibrous product as described in claim 1, wherein the high temperature sterilization process is not performed before the enzyme hydrolysis and fermentation process.