JP2008113630A - Method for producing glucose - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing glucose by which yield efficiency can be improved. <P>SOLUTION: At first, cellulose is acylated to obtain a cellulose ester. For example, cellulose is acylated by reacting the cellulose with acetic anhydride, etc., to obtain cellulose acetate. Then, hydrolysis of the cellulose ester is carried out, e.g. in water or an organic solvent heated at 0°C to 150°C to obtain glucose ester. For example, hydrolysis of cellulose acetate is carried out to obtain glucose acetate. Then, an acyl group of the glucose ester is substituted with hydrogen to obtain glucose. For example, the acyl group of the glucose acetate is substituted with hydrogen to obtain the glucose. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing glucose using cellulose or the like.

  In recent years, industrial use of cellulose, which is the largest biomass produced by nature, has attracted attention. As one of them, the completion of a technique for efficiently producing glucose from cellulose is desired.

  It is known that glucose can be obtained from cellulose by using cellulase. However, since the cellulose substance is solid and its saccharification efficiency is low, the above technique has not been put to practical use. Therefore, researches such as excellent cellulase-producing bacteria and gene improvement are being conducted.

  In addition, experiments for depolymerizing cellulose under a sulfuric acid catalyst are performed, and experiments for depolymerizing using high-temperature and / or high-pressure hot water (400 ° C. or lower) are performed. However, in these methods, levoglucosenone is generated by dehydration in the molecule of glucose, or a furfural derivative is generated by ring opening.

  Thus, conventional techniques cannot efficiently produce glucose from cellulose.

JP 2006-129735 A Koshishima et al., “Functional Cellulose (Popular Edition)”, pages 3 and 195, CM Publishing (2003)

  An object of this invention is to provide the manufacturing method of glucose which can improve acquisition efficiency.

  As a result of intensive studies to solve the above problems, the present inventor has come up with various aspects of the invention described below.

  The method for producing glucose according to the present invention comprises a step of obtaining a glucose ester by hydrolyzing a cellulose ester, and a step of replacing the acyl group of the glucose ester with hydrogen. In addition, before hydrolyzing the said cellulose ester, it is also possible to obtain a cellulose ester by acylating a cellulose.

  According to the present invention, glucose can be obtained stably and with high efficiency.

    Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings. FIG. 1 is a diagram showing a method for producing glucose according to an embodiment of the present invention.

  In this embodiment, first, cellulose ester is obtained by acylating cellulose. For example, cellulose acetate is obtained by reacting cellulose with acetic anhydride or the like for acetylation.

  Next, a glucose ester is obtained by performing hydrolysis of a cellulose ester in water or an organic solvent at 0 ° C. to 150 ° C., for example. For example, glucose acetate is obtained by hydrolysis of cellulose acetate.

  Next, glucose is obtained by replacing the acyl group of the glucose ester with hydrogen. For example, glucose is obtained by replacing the acyl group of glucose acetate with hydrogen.

  According to such a method, since the functional group of cellulose is protected by the acyl group, glucose can be produced stably.

  In addition, you may use the residual cellulose of agricultural products, such as corn, rice, and wheat, as a cellulose.

  In the hydrolysis, an inorganic acid such as sulfuric acid or hydrochloric acid, or an organic acid such as trifluoromethanesulfonic acid, trifluoroacetic acid, acetic acid, or paratoluenesulfonic acid (PTSA) is preferably used as the acid catalyst.

  Moreover, as an organic solvent, an acetic acid, a lower alcohol, acetonitrile, acetone, N-methylpyrrolidone etc. can be used, for example.

  Further, cellulose ester such as cellulose acetate may be used as a starting material without using cellulose as a starting material.

  It is also possible to control cellulose depolymerization and glucosylation hydrolysis by changing the acyl group and / or the degree of substitution.

  Next, the contents and results of an experiment actually performed by the present inventor will be described.

(First experiment)
First, the first experiment will be described. FIG. 2 is a diagram showing the contents of the first experiment. In this experiment, cellulose acetate was used as a starting material.

  First, a mixture composed of 0.50 g of cellulose acetate, 0.50 g of concentrated sulfuric acid and 50 ml of water was prepared, and this was refluxed at 100 ° C. for 24 hours. Next, it neutralized using sodium hydrogencarbonate and concentrated under reduced pressure. Thereafter, sodium sulfate was removed using ethanol. When the residue was subjected to HNMR analysis (Hydrogen Nuclear Magnetic Resonance Spectroscopy), the presence of glucose (production rate: 67%) and sodium acetate was confirmed. Furthermore, some of these were subjected to TLC fractionation (Thin Layer Chromatography Uptake). The results of HNMR analysis in the first experiment are shown in FIG.

  Glucose could also be obtained when the reflux reaction was performed at room temperature, but the amount was less than when the reaction was performed at 100 ° C.

(Second experiment)
Next, the second experiment will be described. In the second experiment, a mixture composed of 0.50 g of cellulose acetate, 0.50 g of concentrated sulfuric acid and 50 ml of water was prepared, and this was reacted in a pressure vessel having an internal temperature of 150 ° C. for 4 hours. Thereafter, the same processing as in the first experiment was performed. The results of HNMR analysis in the second experiment are shown in FIG. In the second experiment, the presence of glucose and levulinic acid was confirmed. It is known that levulinic acid can be obtained by hydrolysis of cellulose.

(Third experiment)
Next, a third experiment will be described. In the third experiment, the catalyst in the first experiment was changed from concentrated sulfuric acid to trifluoromethanesulfonic acid (TFSA) and paratoluenesulfonic acid (PTSA), and the same treatment as in the first experiment was performed. As a result, as in the first experiment, the presence of glucose and sodium acetate was confirmed. Note that the depolymerization reaction progressed better when TFSA was used than when PTSA was used.

It is a figure which shows the manufacturing method of glucose which concerns on embodiment of this invention. It is a figure which shows the content of 1st experiment. It is a graph which shows the result of the HNMR analysis in the 1st experiment. It is a graph which shows the result of the HNMR analysis in the 2nd experiment.

Claims (3)

Obtaining a glucose ester by hydrolyzing the cellulose ester;
Substituting the acyl group of the glucose ester with hydrogen;
A method for producing glucose, comprising:   The method for producing glucose according to claim 1, further comprising a step of acylating the cellulose to obtain the cellulose ester before hydrolyzing the cellulose ester.   The method for producing glucose according to claim 1 or 2, wherein the hydrolysis is performed in water or an organic solvent at 0 ° C to 150 ° C.

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