JP2985003B1 - Production method of bamboo vinegar liquid - Google Patents

Abstract

Abstract: PROBLEM TO BE SOLVED: To efficiently separate and obtain a high-purity bamboo vinegar solution suitable for vinegar and other components from a bamboo dry distillate-containing substance. SOLUTION: When producing a bamboo vinegar solution by distillation from a bamboo dry distillate, the pH of the bamboo dry distillate is adjusted to 9 to 11 alkalinity in advance. Next, aeration with carbon dioxide gas was performed to pH
Until 6.5 to 7 neutral to remove the hydrophobic tar content. In the first distillation step, low-boiling substances are fractionated by distilling and concentrating to about half of the stock solution. The pH of the distillation residue is 2.5
After adjusting the acidity to ~ 3, the mixture is further distilled in the second distillation step until it is dried. Thus, a bamboo vinegar fraction containing acetic acid as a main component and a distillation residue are separated and obtained. An organic solvent is further added to the distillation residue, if necessary, to extract and collect the solvent-soluble matter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a bamboo vinegar solution by distilling a bamboo dry distillate to obtain a bamboo vinegar solution.

[0002]

2. Description of the Related Art Conventionally, it has been widely used to obtain a bamboo vinegar containing acetic acid as a main component by distilling a bamboo dry distillate. However, the simple distillation has insufficiently separated the organic substances in the bamboo vinegar solution. For this reason, for example, methanol, cresol, and phenols harmful to humans and animals are inevitably mixed into bamboo vinegar, and the resulting bamboo vinegar is difficult to use as vinegar, and its use is significantly limited. It had been.

[0003] On the other hand, the tar component containing cyclopentenone and formaldehyde in the bamboo distillate is obtained by adding calcium carbonate to the bamboo distillate and foaming carbon dioxide gas generated by the reaction with the acid in the bamboo dry distillate. It is known that this is floated, and the pH is adjusted to 6.4 or more by adding sodium hydroxide, and then the tar component is separated and removed by a membrane or standing (Japanese Patent Application Laid-Open No. 9-249886). . However, this method has a disadvantage that a large amount of alkali salt remains due to the combination of calcium carbonate and sodium hydroxide. Also, by simply adjusting the pH of the acidic bamboo dry distillate to neutral, in the distillation step, various low-boiling compounds contained in the bamboo dry distillate such as methanol and cresol, which are harmful to the human body, and acetic acid azeotrope, and as it is. Then it was difficult to serve for food.

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems and provides a method for producing a bamboo vinegar solution which can obtain a bamboo vinegar solution suitable for vinegar and efficiently separate and acquire other components. It is intended to provide.

[0005]

According to the method for producing a bamboo vinegar of the present invention, which achieves the above object, when producing a bamboo vinegar by distillation from the bamboo dried distillate, the pH of the bamboo dried distillate is previously adjusted to 9 to 10.
After adjusting the alkalinity to 11, the mixture was aerated with carbon dioxide gas until the pH became neutral to 6.5 to 7 to remove the hydrophobic tar component. The boiling point organic substance is distilled off, and the pH of the concentrated solution is adjusted to 2.5 to 3 and then further distilled to dryness to separate a distillate residue and a bamboo vinegar liquid fraction containing acetic acid as a main component. It is characterized by acquiring.

Further, a useful solvent-soluble matter can be extracted and recovered by further adding an organic solvent to the distillation residue.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of a method for producing a bamboo vinegar according to the present invention will be described with reference to the drawings. In FIG. 1, bamboo dry distillation liquid 1 as a raw material is obtained by, for example, dry distillation of Moso bamboo in a gas furnace, and water-cooling and collecting components obtained in a temperature range of 200 to 250 ° C., and sedimentation of tar components in a dark place. To use. The pH of this dry distillation solution is usually about 2 to 3. In the present invention, after the bamboo dry distillate 1 is solid-liquid separated by a membrane, for example, p
Adjust H to 9-11 alkaline. At this time, acidic components such as acetic acid are dissociated into carbonyl ions, and phenols form phenolates and cannot be distilled.
At a pH of 9 or less, the phenols do not sufficiently form phenolate, and may cause turbidity. Also, p
In order for H to be 11 or more, a large amount of an alkaline compound needs to be added, and a large amount of sulfuric acid is required in a subsequent neutralization step, and as a result, a large amount of salt is generated, which is not economical. Next, in the aeration step 2, bubbling with carbon dioxide gas is performed. Aeration is performed until the pH is neutralized to 6.5 to 7 by the generated carbonic acid. In order to reduce the pH to 6.5 or less, a long-term bubbling of carbon dioxide is required, which is not practical. At a pH of 7 or more, phenols may remain as phenolates and remain without being distilled off in the first distillation step. At the same time, the tar component in the bamboo dry distillate separates and floats by bubbling of carbon dioxide gas. For the separated tar component, for example, an adsorbent cloth such as a Teflon cloth is supplied during bubbling, and the tar is adhered and removed. After bubbling, a Teflon cloth may be added to the bamboo dry distillate again and stirred for about 30 minutes to remove and adhere.

The clear bamboo dry distillate from which the tar component has been removed is distilled in the first distillation step 3. The distillation may be carried out at normal pressure, but vacuum distillation is practical. The distillation temperature is preferably controlled at 60 to 80 ° C. to avoid bumping. In the first distillation step 3, the distillation is performed until the amount of the bamboo dry distillate becomes about half of the initial amount. In the first distillation step 3, methanol is almost completely distilled off to the first distillate 4 side. At the same time, other harmful substances as vinegar such as neutral components, phenols and cresol in the bamboo dry distillate are distilled off.

[0009] A strong acid such as sulfuric acid is added to the distillation residue 5 concentrated to about half of the initial amount of the bamboo dry distillate to add a slightly smaller amount than the equivalent amount of sodium hydroxide added earlier to adjust the pH.
Adjust to 2.5-3 acidity. In this case, the pH is 2.4
In the following case, sulfuric acid is mixed in the bamboo vinegar in the next second distillation step, so care must be taken not to add too much. By making the pH strongly acidic, acidic components such as acetic acid are in a non-dissociated state. If the pH is 3 or more, acetic acid forms sodium acetate and distillation becomes impossible, and the yield of acetic acid decreases. If necessary, at this stage, a Teflon cloth or the like is again charged and stirred to remove tar. Next, in the second distillation step 6, the distillation residue 5 is heated to about 80 to 100 ° C. for the same reason as described above.
And distill to dryness. The distillation may be carried out at normal pressure, but vacuum distillation is preferred. Most of the acidic components including acetic acid are contained in the second distilled liquid 7 distilled off.
Thus, a bamboo vinegar liquid containing acetic acid as a main component, which is the target substance, is obtained. In this case, the added alkaline compound such as sodium hydroxide reacts with a strongly acidic compound such as sulfuric acid to form a salt such as sodium sulfate, and there is no possibility of distillation.

On the other hand, since the distillation residue 8 contains useful organic compounds having a physiological activity such as high-boiling polyphenols, it can be extracted with a solvent such as acetone or alcohol if necessary. The obtained solvent extract was evaporated to dryness, dissolved in ethanol or the like, and separated by column chromatography or the like in the extraction and recovery step 9. When the solvent extract was separated by column chromatography or the like, several A component groups 10 and B components It can be obtained by dividing into groups 11 and the like.

[0011]

Example 1 In the bamboo dry distillate, only Moso was carbonized in a gas furnace, and the components carbonized at a furnace upper temperature of 200 to 250 ° C. were recovered by water cooling and stored in a dark place for two months to remove tar components. The sedimented one was used. Its composition is organic 7.4
%, Water 92.6%, and acetic acid 3.4%. A light tan solution with a specific gravity of 1.01 and a pH of 2.4.

The bamboo dry distillate was filtered through a membrane filter having a pore size of 3 μm, and the pH was adjusted to 11 by adding a 4 mol / l aqueous sodium hydroxide solution to 1 liter. Next, carbon dioxide gas was fed into the solution until the pH of the solution reached 6.5, followed by bubbling, and the tar content floating during that time was attached to a Teflon mesh cloth and removed.

The bamboo dry distillate from which the tar had been removed was transferred to a distillation flask, set in a vacuum distillation apparatus, and distilled at 60 to 80 ° C. until the amount of the solution became about half. As a result of analyzing the distillate distilled off by gas chromatography, phenol, cresol, guaycol, methanol and the like were detected.

The distillation residue is placed in a beaker, and 2 mol / l
Was added with stirring to adjust the pH to 2.7. pH
As a result, carbon dioxide gas bubbles were generated from the distillation residue, and the tar component floated again. Therefore, it was removed again with a Teflon mesh cloth as before. The pH-adjusted distillation residue was distilled under reduced pressure at 80 to 100 ° C. until dried. As a result of analysis of the distilled liquid distilled off, most of the liquid was acetic acid. There was a trace amount of phenols, but no methanol. As a result, it was found that this bamboo vinegar solution can be used as vinegar.

On the other hand, 100 ml of acetone was added to the distillation residue, insolubles were filtered off with a membrane filter, and acetone-soluble components were extracted and recovered. The insolubles contained large amounts of sodium sulfate and small amounts of salts such as sodium acetate. The acetone extract is distilled to completely remove the acetone, and then dissolved in 50 ml of a 50% ethanol solution. The solution is supported on a column filled with 500 ml of a porous polystyrene resin, and then distilled water, 25% ethanol, 50% ethanol,
Elution was carried out sequentially using 100% ethanol, and the acetone extract was further separated. Each eluate was positive in the phenol qualitative test using ferric chloride, and is presumed to contain a high-boiling polyphenol component. still,
The production method of the present invention can be applied to the production of wood vinegar.

[0016]

According to the present invention, there are the following advantages, and a bamboo vinegar solution that can be used as vinegar can be efficiently obtained. In addition, since various active components in the bamboo dry distillate can be separated, components according to the purpose of use can be separated and obtained.

(1) Prior to the first distillation step,
Once the pH is adjusted to about 9 to 11 alkalinity, carbonylation of acetic acid is prevented from being distilled off together with low-boiling compounds, and the yield of acetic acid in the second distillation step is improved.

(2) By removing tar by using carbon dioxide gas instead of calcium carbonate, mixing of extra elements such as calcium can be prevented, and the type and amount of insoluble metal salt in the final distillation residue can be reduced. At the same time, the carbonized bamboo distillate is neutralized with carbonic acid, and phenols are released.
It facilitates its removal by distillation.

(3) Prior to the second distillation step, the distillation residue is adjusted to a strongly acidic pH of about 2.5 to 3 to facilitate the recovery of acid components such as acetic acid by distillation, and to improve the purity of the bamboo vinegar solution. The yield is improved, and it can be used as vinegar.

(4) A useful solvent-soluble, high-boiling organic compound can be recovered from the distillation residue by extracting a solvent such as acetone or alcohol, if necessary.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a method for producing a bamboo vinegar solution according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bamboo dry distillate 2 Aeration process 3 First distillation process 4 First distillate 5 Distillation residue 6 Second distillation process 7 Second distillate 8 Distillation residue 9 Extraction and recovery process 10 A component group 11 B component group

Claims (2)

(57) [Claims] 1. In producing a bamboo vinegar solution by distillation from a bamboo dry distillate, the pH of the bamboo dry distillate is previously adjusted to 9 to 11 alkalinity, and then the pH is adjusted to 6.5 to 7 with carbon dioxide gas.
To remove the hydrophobic tar content by aeration until neutral, and distill and concentrate to about half of the original bamboo dry distillate to evaporate low boiling organic substances. A method for producing a bamboo vinegar solution, which comprises adjusting the acidity of the solution to an acidity and further distilling it to dryness to separate and obtain a bamboo vinegar liquid fraction containing acetic acid as a main component and a distillation residue. 2. The method for producing a bamboo vinegar solution according to claim 1, wherein a solvent-soluble component is further extracted from the distillation residue by solvent extraction.