JPS6213333B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for industrially producing phenols from coconut shell dust at low cost and efficiently. The phenols obtained according to the present invention are lignin-related so-called 4-hydroxyphenyl, guaiacyl and syringyl phenols.
These lignin-related phenols are industrially effective substances used as raw materials for polymer synthesis or fine chemical raw materials for perfumes, pharmaceuticals, and the like. Conventionally, phenols have been produced using petroleum as a starting material. However, in order to produce the above-mentioned lignin-related phenols, it is unavoidable to go through a multi-step reaction. On the other hand, the method of decomposing lignin is efficient because lignin-related phenols can be efficiently obtained in one step. For this reason, vanillin is industrially produced from lignosulfonic acid in pulp wastewater at a yield of about 10% based on lignin. On the other hand, the finite nature of fossil resources has been pointed out, and there is a strong demand for the development of alternative resources. In coconut palms, most of the coconut shells are discarded after the fruit is harvested. Currently, there is no effective use of coconut shell dust, and it is not being considered as a raw material for producing phenols. As a result of various research into the effective use of this coconut shell dust, the present inventor found that this
It was discovered that it contains as much as 40% by weight of lignin (usually around 30%) and is effective as a raw material for producing phenols, leading to the completion of the present invention. That is, according to the present invention, phenols are obtained from coconut shell dust by separating the dust part from the coconut shell, performing alkaline oxygen oxidative decomposition using cobalt () as a catalyst, and then separating the produced phenols by an extraction method. A method is provided for manufacturing a class of products. To preferably carry out the method of the present invention, first,
The coconut shell is crushed, the crushed material is divided into a dust part and a fiber part, and the dust part is collected. It is effective to crush the dust using a disk-cliffing ironer, and to separate the dust from the crushed material, it is possible to float the crushed material to the water surface, separate it from the fibrous portion that settles in the water, and collect it. can. Next, the coconut shell dust thus separated is dried by air-drying or the like, and then pulverized by a Wiley mill or the like and subjected to oxidative decomposition. The decomposition conditions used in the present invention are 2N to 4N
of sodium hydroxide or potassium hydroxide as a medium, oxygen pressure of 3 to 10 Kg/cm ² , reaction temperature of 130°C
~165℃. The amount of cobalt () used as a catalyst is 5 to 20 mmol per 1 g of lignin. In this case, cobalt hydroxide (2) used as a catalyst can be obtained by placing cobalt sulfate (2) or cobalt chloride (2) in a reaction vessel, adding an alkali thereto, and then treating the mixture with hydrogen peroxide. The amount of cobalt hydroxide present in the reaction system has a concentration of 1.1 to 5.5% by weight, preferably 2 to 4% by weight. In this case, as the alkali used for normality adjustment, a strong base such as sodium hydroxide or potassium hydroxide is used. Further, oxygen or air is used as the oxidizing agent in the present invention. Example 1 A dust part of a coconut shell from Indonesia (so-called coir dust) was used as a sample. The coir dust was separated from the fiber part using a disk-cliffing iner, and then pulverized using a Wiley mill. A sample degreased with an alcohol/benzene mixed solvent was subjected to oxidative decomposition. 1.0 g of coir dust degreased powder, cobalt () and 50 ml of a 12% aqueous sodium hydroxide solution were placed in a 100 ml stainless steel autoclave, and oxygen was further pressurized at 5 kg/cm ² . For cobalt (), 3.0 g of cobalt sulfate () hydrate was dispersed in 40 ml of a 5% aqueous sodium hydroxide solution, which was then oxidized with 10 ml of 30% hydrogen peroxide. reaction mixture
The mixture was heated to 145°C and decomposed for 6.5 hours under stirring. After the reaction was completed, the reaction mixture was centrifuged to separate the alkaline water-insoluble portion, which was further washed with water. The resulting aqueous solution was acidified to PH1 with hydrochloric acid, and extracted with ether. Next, the ether extract was dried over anhydrous sodium sulfate, and the ether was removed to obtain an oxidative decomposition product. Analysis of oxidative decomposition products was performed by gas chromatography. That is, the oxidative decomposition product was dissolved in dry pyridine, bis(trimethylsilyl)acetamide was added thereto to perform silylation, and the product was subjected to analysis by gas chromatography. The gas chromatograph results are shown in Table 1. The measurement conditions were as follows. Column; stainless steel 2m, packing material;
siliconeOV-1, column temperature: 120-220℃, heating rate: 5℃/min, carrier gas: nitrogen

[Table] The analysis results are shown in Table 2. Example 2 A sample was pretreated with heated steam at 20 kg/cm ² (approximately 210° C.) and then exploded by rapidly releasing it into the atmosphere, and was decomposed under the same conditions as in Example 1. The results are also shown in Table 2.

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Claims (1)

[Claims] 1. A method for producing lignin-related phenols, which comprises oxygenating and decomposing coconut shell dust (non-fiber part) in the presence of an alkali using cobalt () as a catalyst.