RU2279284C1 - Method for integrated utilization of larch wood - Google Patents

Abstract

FIELD: pharmaceutical, cosmetic and food processing industry, in particular method for integrated utilization of larch wood.

SUBSTANCE: claimed method includes disintegration of larch wood having certain relative humidity in presence of ethanol up to specific particle size. Obtained ground pulp is extracted with ethanol under specific conditions, then solid and liquid phases are mechanically separated; ethanol with dissolved therein dihydroxyquercitine is mechanically recovered from liquid phase; liquid phase is filtered, boiling down; mixture of essential oils and fat organic acids useful in cosmetic industry is isolated from obtained concentrate. Dihydroxyquercitine is recovered form the rest organic phase. Whole process is carried out at specific temperature.

EFFECT: increased dihydroxyquercitine yield; simplified process; integral utilization of raw materials.

4 cl, 1 dwg, 3 ex

Description

The invention relates to the production of plant extracts containing biologically active substances (BAS) and can be used in the pharmaceutical, food, cosmetic industry.

Having a high antioxidant activity, DHA is used in medicine because it has the ability to restore the elasticity of blood capillaries, inhibits inflammatory processes, has the ability to prevent the formation of tumors, etc. In addition, DHA is used in the food industry as a preservative and in a number of areas of biotechnology (MN Zaprometov. Phenolic compounds, M .: Nauka, 1993).

A known method for the isolation of DHA by extraction of larch wood sawdust with water when heating, cooling the extract, filtering, chromatography on a column with polyamide, eluting with water-acetone mixture and evaporation (USSR copyright certificate No. 351847, 1970).

The main disadvantage of this method is the long duration of the process of bioflavonoid isolation, as well as the need to use complex operations using a high-purity polyamide sorbent to extract DHA from the aqueous extract. The production of DHA in this case is inevitably associated with noticeable product losses due to the need for sorption and desorption processes, the complexity of the necessary regeneration of the polyamide sorbent, with a low yield of the target product of 1.1-1.2% by weight of absolutely dry wood, and, in addition to Moreover, the use of a water-acetone mixture and high temperatures during the process of isolation of the final product.

There is also a method for the isolation of DHA by extracting larch wood with water while heating, cooling, filtering and stirring the extract for 2 hours with a polyamide sorbent in a ratio of 1:10, filtering and drying the polyamide powder, extracting DHA from the polyamide powder with ethyl acetate, distilling off the solvent and subsequent crystallization its out of hot water. The output of DHA is 0.5-0.6 wt.% In terms of the mass of absolutely dry wood with a degree of purification of the target product of 94-97% (RF patent No. 2000797, 1993).

The disadvantage of this method is the duration of the process, the use of expensive polyamide sorbent of high purity, as well as significant energy costs, since the extraction process with water lasts 1 hour with a 10-fold excess of water with a temperature of 100 ° C, a relatively low yield of the target product.

Closest to the claimed invention in technical essence is a method for the extraction of DHA by processing chopped wood, while larch wood is processed with water when heated, the solid phase is separated, the pulp is cooled, the organic solvent is added and evaporated. Water is ionized. The organic phase is passed through a carbon filter before evaporation. Evaporation of the organic phase is carried out under vacuum. The solvent used is methyl tert-butyl ether (RF patent No. 2180566, 2001).

The disadvantage of this method is that it requires large quantities of organic solvents up to 10 tons per 1 ton of dry wood, a significant investment of time for the extraction process and for the production of flavonoids involves the use of methyl tertiary butyl ether, as well as water at temperatures of 70-92 ° C. In addition, after evaporation of the target product, DHA crystallizes from hot water, which does not contribute to obtaining a high-quality final product. The disadvantages of the method include obtaining only one final product.

The objective of the present invention is to provide an effective industrial method for the isolation of two final products, which allows to reduce the time of the technological cycle, to simplify the technology, and at the same time to obtain a number of high-quality final products in their native form.

The claimed method allows, in comparison with the above methods, to ensure the most complete use of the feedstock, to simplify the process and, thereby, reduce the loss of raw materials, as well as reduce the total time of the process, as well as the consumption of organic solvents and simplify the process flow and instrumentation upon receipt of the final products, and increase the yield of DHA.

The problem is solved by the method of complex processing of larch wood with the production of natural substances, including grinding the butt of the larch, exposure to organic solvents that do not contain carcinogenic components, mechanical extraction of the pulp, settling of the resulting liquid with the release of a mixture of essential oils, fatty organic acids; extraction and evaporation of the organic phases of the extract with the selection of the target end products from the obtained organic phases, all phases of the process being carried out in an oxygen-free environment, in which, according to the invention, the process of processing larch wood is carried out in two stages. At the first stage, wood is machined with special milling cutters and special cutters in order to obtain fine chips, while the whole process takes place in the presence of ethyl alcohol, which serves both as a solvent and a coolant. The use of this method of wood chopping has the following advantages:

- the grinding process allows you to get small chips with a size of not more than 0.1 mm;

- the use of ethyl alcohol prevents the process of oxidation of DHA at the time of grinding;

Grinding without ethyl alcohol raises the temperature at the contact point of the cutter and wood to 180 ° C, which in the presence of atmospheric oxygen leads to the rapid oxidation of DHA.

- after applying the grinding method described above, a ready-made alcoholic pulp is obtained ready for extraction;

- this method of wood chopping is dust-free, which reduces the fire and explosion safety of the process and does not increase the noise level according to SanPiN 245-87.

At the second stage, the extraction of DHA from the pulped pulp takes place. This process is carried out using an emulsifier-extractor type RGGD, the use of which allows you to fully extract DHA into an alcoholic emulsion due to the design features of the RGGD, which uses the principle of water hammer.

After extraction, the pulp is sent to a centrifuge, where the process of separation of the liquid and solid phases occurs.

The solid phase is directed to special rolls, where the process of extruding the residues of ethyl alcohol and the DHA dissolved in it takes place, which allows almost completely isolating the DHA from sawdust with maximum solvent retention.

The use of specialized rolls (P - pressure = 20-30 atm) gives the maximum effect in the release of DHA from sawdust, since the extrusion process destroys the internal cavities (follicles) in the wood fibers, followed by the release of DHA from them into an alcohol emulsion.

Sawdust obtained after passing through the rolls has a moisture content of not more than 40%. Sawdust is stored and the alcohol emulsion is sent to emulsify a new batch of alcohol pulp.

The problem is solved by thorough preliminary mechanical preparation of wood in an alcohol environment before being placed in the extractor, and during extraction, ethanol is used as a solvent, the organic phase is separated from the resulting pulp mechanically using specialized rolls, which are evaporated.

And also because

- the temperature at all stages of the process does not exceed 36 ° C;

- the process of processing larch wood is carried out in the extractor RGGD;

- maintain the mass number of alcohol to wood 3-10: 1;

- the organic phase is passed through a filter before evaporation;

- the solvent is used repeatedly in circulation to extract the greatest amount of organic substances from wood;

- after evaporation produce separation of raw materials for cosmetic products;

- the remaining mass is filtered and used to obtain DHA.

The essence of the method is illustrated by specific options for its implementation and the drawing, which shows the technological scheme of the sequence of operations.

The method is as follows.

Raw materials before being immersed in the extractor are mechanically treated with a mill and a special cutter in ethanol at an optimum ratio of liquid to solid phase of 3-10: 1, which allows to obtain wood particle sizes of not more than 0.1 mm, while the temperature of the feedstock does not exceed 36 ° C .

The mixture enters the RGGD extractor, where the pulp stays for 10-15 minutes. During this time, the components contained in the degraded wood go into an alcohol solution, then the pulp is mechanically pressed. The alcohol essence is sent to vacuum evaporation columns for reuse of alcohol. In the second stage, fatty acids and resins, essential oils are extracted from the obtained DHA concentrate, and the remaining phase is used to extract DHA.

The essence of the method is illustrated by specific options for its implementation and the drawing, which shows a schematic diagram of the technological process for obtaining final products, where 1 is the grinding of wood in ethyl alcohol; 2 - extraction of raw materials in the RGGD; 3 - spin pulp in the rolls; 4 - a solution of alcohol and substances dissolved in it from wood (alcohol essence); 5 - vacuum-evaporation columns, where alcohol is separated for repeated use, 9.9 ¹ - ethanol, used on the principle of recycled use; 6 - separation of final products and the selection of cosmetic raw materials in the form of resins and essential oils; 8 - final purification of DHA; 9 - fractionation of cosmetic raw materials.

The extraction of DHA from the pulp is carried out in the apparatus RGGD with ethanol taken in the amount of V _alcohol : V _wood , equal to 3-10: 1. Ethyl alcohol has valuable technological properties and is cheap. It has a boiling point favorable for the process / 36 ° C /, it dissolves very well organic compounds of medium polarity, which include DHA. It is very important that ethyl alcohol, in contrast to the ether solvents known for this process, such as methyl tert-butyl ether, diethyl ether, is more preferable in terms of explosion safety.

The alcohol essence after squeezing the pulp in the rolls enters the vacuum evaporation columns to separate the liquid phase of ethyl alcohol, which is sent for recycling to the RGGD extractor. After vacuum evaporation and the crystallization process, a DHA concentrate is obtained with a yield of 2.6-2.8 wt.% In terms of absolutely dry wood with a purity of 90-92%.

The proposed method can be implemented using standardized equipment.

Specific examples of the implementation of the method:

Example 1. Chips of the butt part of a larch with a relative humidity of 30-40 wt.%, Containing up to 3.5% of DHA, are loaded into a container with ethyl alcohol at a ratio of 1: 5, respectively, where they are machined to obtain wood particles with linear dimensions L × B × H = 0.1 × 0.1 × 0.1 mm, and the ratio of solid and liquid phase is 1: 5.

The pulp from the tank 1 through the valve enters the extractor RGGD - 2 and mixes thoroughly. The process is conducted for 5 minutes at a temperature of 25 ° C. After the process, the pulp with a temperature of 25 ° C is fed to the mechanical rolls 3 at a pressure of 10-30 atm., Where the process is carried out at least two times. After that, the sawdust is dumped into the dump, and the pulp with a temperature of up to 25 ° C from mechanical rolls 3 is fed into vacuum evaporation columns of the 5th type VVK-1. The concentrate DHA is collected in a container 6. The selection of cosmetic raw materials produced in the installation of the RK-1 in the amount of 0.05 l The composition of the raw materials for cosmetics in the amount of 0.04 l (loss is 0.01 l.) From the apparatus RK-1 enters the separator to separate the liquid organic phase. The organic phase in an amount of 4.5 l is filtered and evaporated in a vacuum apparatus VVK-1 and crystallized. Obtain 24 g of DHA composition C ₁₅ H ₁₂ O ₇ . The degree of purity is 90-92%, the yield is 2.6 wt.%, Calculated on the mass of absolutely dry wood; after the post-treatment process, 16 g of DHA with a purity of at least 95% are obtained.

To establish how much DHA corresponds to the standard sample TAXIFOLIN obtained by the proposed method, the American company SIGMA conducted a comparative study of the spatial structure of both samples. SIGMA TAXIFOLIN with a purity of at least 85% was chosen as the standard, the parameters of which are given in the company catalog, position T4512. Studies have shown that DHA obtained by the proposed method is a compound having two asymmetric centers (C2 and C3). From the study of its spatial structure, DHA was refined using HPLC in both analytical and preparative versions on a Milichrome A02 instrument to a purity of 99%, then the molecular weight was determined by MALDI mass spectrometry - in two versions - using a standard matrix - 2,5-dihydroxybenzoic acid (DHB) and with application of a matrix-free DHA onto the target (device - Brucker reflex III). Analysis with DHA using NMR spectrometry in DMSO-d6 allowed us to strictly establish the spatial structure of the DHA obtained by the proposed method — the protons at C2 and C3 are in transposition, and the exact formula of the compound is (R2, R3) -3.3 ', 4 ', 5,7-pentahydroxyflavon. (A Brucker DRX 500 spectrometer was used at frequencies of 500.13 MHz ( ¹ N) and 125.76 MHz ( ¹³ C)). The construction of a molecule model in the framework of the HyperChem program confirmed the correctness of the results.

This allowed us to conclude that the two samples were completely identical, and that the DHA obtained by the proposed method consists exclusively of monomeric molecules.

The molecular weight of 304.25, T-22 ° C, a density of 1.49 g / cm and a melting point of 237 ° C.

The chemical composition of the DHQ was proved by elemental analysis on C, H, O and by high performance liquid chromatography by HPLC on a VARIAN STAR instrument with a UV detector / 292 nm /.

Example 2. Similar to example 1. The process is conducted with a ratio of crushed wood to alcohol equal to 1: 3. Processing time - 10 min. Processing temperature 22 ° C. After separation, the organic phase is passed through a carbon filter, after which the purified organic phase in an amount of 1.5 L is sent for evaporation to apparatus 5. Receive 2.7 wt.% (In terms of absolutely dry wood) DHQ 99.0% purity.

Example 3. Similar to example 2. The process is carried out with a ratio of wood to ethanol equal to 1:10. Processing time 5 min. Processing temperature 23 ° C. After separation, the organic phase is passed through a carbon filter, which is a carbon fiber. The yield of 2.8 wt.% (In terms of absolutely dry wood) DHA with a purity of 99.0%.

The proposed method allows you to get DHA with a yield of up to 2.6-2.8% by weight of absolutely dry wood with a purity of 95-98%, significantly simplify the process technology, reduce the cost of the process, since the temperature of wood processing with alcohol occurs at a normal temperature of about 20- 25 ° C, the duration of the process as a whole is reduced, and the yield of the final product (the yield of native substances) is increased, while all processes are carried out in an inert environment without oxygen.

Claims (4)

1. The method of complex processing of larch wood, characterized in that larch wood with a relative humidity of 30-40 wt.% Is crushed in the presence of ethyl alcohol to a particle size of not more than 0.1 mm, the resulting crushed pulp is extracted with ethyl alcohol at an extractant-raw material ratio of 3 -10: 1 for 5-10 min at a temperature of 22-25 ° C, then the solid and liquid phases are separated mechanically, ethanol with dihydroquercetin dissolved in it is separated mechanically, and the liquid phase is filtered, then parivayut, isolated from the resulting concentrate mixture of essential oils and fatty organic acids for use in the cosmetic industry, and the remainder of the organic phase is recovered dihydroquercetin, the entire timber recycling process is conducted at a temperature not exceeding 36 ° C. 2. The method according to claim 1, where the extraction process of crushed pulp is carried out in an emulsifier-extractor type RGGD, which uses the principle of water hammer. 3. The method according to claim 1, where from the solid phase, ethyl alcohol and dihydroquercetin are isolated by mechanical extraction using rolls at a pressure of 10-30 atm. 4. The method according to claim 1, where the evaporation of the organic phase is carried out under vacuum.