RU2233858C1 - Method for complex processing larch wood - Google Patents

Abstract

FIELD: wood working industry.

SUBSTANCE: invention relates to a method for processing lignin-carbohydrate raw, namely: larch wood, in particular, waste in wood processing - base parts of Dahurian and Siberian larch to obtain biologically active flavanoid - dihydroquercetin that is used in medicine and food industry, natural resinous substances for preparing colophony, surface-active substances, perfume substances, virusocides and technical products also: phosphorylated wood that is used as sorbent of heavy and radioactive metals, silylated wood eliciting the enhanced hydrophobicity and resistance against decaying, acylated wood eliciting prolonged antibactericidal properties. Method for processing larch wood involves treatment of destructurized wood in fluidized state, separation of prepared pulp for liquid and solid phase, separate treatment of liquid and solid phase with organic solvent, isolation of dihydroquercetin and natural resins and the following treatment of remained wood mass. Treatment of destructurized wood in fluidized state is carried out with deionized water in rotor pulse device at 70-92 C and the mass ratio wood : deionized water from 1:4 to 1:10 for 5-15 min. The solid phase obtained after separation of pulp before treatment with organic solvent is subjected for drying up to humidity 9-11 wt.-% and methyl-tert.-butyl ester is used as an organic solvent. Treatment of solid phase with methyl-tert.-butyl ester is carried out at 50-55 C to isolate natural resins from prepared solution and remained activated wood mass is subjected for interaction with phosphorylating, silylating or chloroacylating agent at 60-70 C. method provides simplifying technology for complex treatment of wood and to expand assortment of products obtaining after it processing to prepare dihydroquercetin with the yield 2.2-2.5% of dry wood mass and purity degree 95-96%; natural resinous substances with the yield 2.5-3%; phosphorylated derivatives of wood with phosphorus content 11.3-11.4%; silylated derivatives of wood with silicon content 10.1-10.2%; chloroacylated wood with chlorine content 15.3-15.5%.

EFFECT: improved processing method.

1 dwg, 3 ex

Description

Larch wood contains lignin, cellulose, a set of mono- and oligomolecular organic compounds and mineral salts. All these substances are of interest for solving urgent applied problems.

The invention relates to the field of processing lignin-carbohydrate raw materials, namely: larch wood, in particular wood processing waste - the butt of the Siberian and Daurian larch to produce a biologically active flavonoid - dihydroquercetin, which is used in medicine and the food industry, natural resinous substances for obtaining rosin, surfactants , aromatic substances, virusoids, as well as technical products: phosphorylated wood, which is used as a sorbent for heavy and radioactive meta lyes, silylated wood, which has increased hydrophobicity and resistance to decay, acylated wood, exhibiting prolonged antibacterial properties.

Currently, several methods have been patented for isolating the important flavonoid dihydroquercetin (DHA) from wood (RF patent 2114631, 1998; RF patent 2180566, 2002) and arabinogalactan (RF patent 2002756, 1993).

Existing methods for producing DHA are characterized by a low coefficient of wood utilization (about 20-30%) or using only drill timber as feedstock.

Closest to the proposed invention is a known method of processing larch wood, including extraction of natural substances from degraded wood by treatment with an organic solvent containing water, separation of the extraction mass into an extract and a solid phase in the form of a carbon-containing polymer of wood, which is isolated as the target product and / or subjected carbonization in an inert gas atmosphere to obtain a wood activated carbon form; absorption of the extract with a solvent, Highlighted derived from organic and aqueous phases corresponding desired products. The isolation of the target products is carried out as follows: the larch wood extraction process is carried out in two stages under the conditions of the components of the extraction mass being in a fluidized state, and in the first stage, an emulsion of non-polar aliphatic hydrocarbon in water is used as a solvent, and the obtained extraction mass after the first stage is divided into solid phase and a water-hydrocarbon extract, which is divided into a hydrocarbon solution of natural resins and an aqueous solution of oligosaccharides from the last by isolating natural resins and oligosaccharides, and the obtained solid phase after washing with water is sent to the second stage of extraction using an emulsion of low-boiling ether and aqueous ethyl alcohol in water as a solvent, and the obtained extraction mass from the second stage is separated into an aqueous ether extract and a solid phase, in the form native carbon-containing polymer of wood, and the absorption of water-alcohol-ether extract is carried out by low-boiling ether, followed by separation from the resulting alcohol-ether and water phase of native bioflavonoids - dihydroquercetin (DHA) and dihydrocemferol, as well as oligosaccharides, all stages of the wood processing process being conducted in an inert gas atmosphere, wood pulp formed after wood extraction with water is used in pyrolytic processes to form carbon black (RF patent 2165416, 2001). This product in many ways resembles carbon black obtained from wood that has not undergone preliminary extraction.

The disadvantage of the prototype is the use in the process of a large number of organic solvents: expensive hexane, or gasoline, which, as a rule, contains toxic and difficult to remove aromatic hydrocarbons, acetone, ethyl alcohol, as well as the need for separate operations under high pressure. As a result of the process, only one product is obtained from the wood pulp remaining after extraction — activated carbon.

The objective of the invention is to simplify the technology of integrated processing of wood and expanding the range of products of its processing.

This result is achieved by the fact that in a method of processing larch wood, including processing of degraded wood in a fluidized state, separating the resulting pulp into a liquid and solid phase, separately treating the liquid and solid phase with an organic solvent, isolating dihydroquercetin and natural resins and subsequent processing of the remaining activated wood pulp , the treatment of destructured wood in a fluidized state is carried out with deionized water in a rotary pulsation device at 70-92 ° C and a mass ratio of wood: deionized water from 1: 4 to 1:10 for 5-15 minutes, and the solid phase obtained after separation of the pulp is dried before being treated with an organic solvent to a moisture content of 9-11 wt. %, methyl tert-butyl ether is used as an organic solvent, the solid phase is treated with methyl tert-butyl ether at 50-55 ° С to isolate natural resins from the resulting solution, and the remaining activated wood pulp is reacted with phosphorylating, silylating, or chlorine ratsiliruyuschim agent at 60-70 ° C.

The main (by weight) product is activated wood pulp, which includes a cellulose-lignin complex. It refers to products that are fundamentally different from the original wood by the high friability of its structure, which determines its increased reactivity in phosphorylation, silylation and acylation reactions to produce new valuable materials, such as phosphorylated woods, which are of interest as chiral ligands and heavy sorbents, including the number of radioactive materials, silylated woods - hydrophobic products for building and other structures, acylated woods - pesticides prolon carbonated action, etc.

At the same time, a previously unknown circumstance should be emphasized: the effectiveness of these chemical modifications is determined by the degree of activation of the initial complex, and it is determined by the duration of the process of water treatment in a rotary pulsating device (cavitation). The method provides for the possibility of using as raw materials, in addition to high-quality wood, waste from the root or root part of the Siberian or Daurian larch.

- As a phosphorylating agent, for example, amides of trivalent phosphorus acids are used.

- As a silylating agent - for example, hexamethyldisilosane.

- As a chlorinating agent - for example, monochloracetic acid chloride.

The proposed method allows to obtain:

- dihydroquercetin with a yield of 2.2-2.5% by weight of dry wood with a purity of 95-96%;

- natural resinous substances with a yield of 2.5-3%;

- phosphorylated wood derivatives with a phosphorus content of 11.3-11.4%;

- silylated derivatives of wood with a silicon content of 10.1-10.2%;

- chlorinated wood with a chlorine content of 15.3-15.5%.

The invention is illustrated by specific examples of its implementation and the drawing, which shows a schematic diagram of the installation, where 1, 11 are tanks, 2 is a shut-off valve, 3 is a cavitator reactor, 4 is a centrifuge or filter, 5 is an intermediate tank, 6, 13 is extractors, 7 - separator, 8 - apparatus for vacuum distillation of the solvent, 9 - carbon filter, 10 - crystallizer, 12 - apparatus for drying, 14 - reactor for chemical modification of activated wood, 15 - apparatus for distillation of the solvent.

The method is as follows: larch wood, for example, waste from the wood processing industry (sawdust, shavings, chips, etc.), is loaded into a container 1, then the calculated amount of deionized water is added to a mass ratio of solid and liquid phases of 1: 4-10.

The mixture from the tank 1 through the shut-off valve 2 enters the reactor 3, which is a rotary pulsation device (power of the order of 30 kW), for example a cavitator, and then returned to the tank 1, the temperature in the cavitator is maintained at 70-92 ° C.

In a cavitator with a pressure drop, the extraction process is accompanied by the simultaneous destruction of the biological structure of wood, while water with the substances dissolved in it passes from the liquid phase to a degraded fluidized state, characterized by a decrease in viscosity and an increase in fluidity, all this contributes to the most complete extraction of DHA from wood, as well as optimal activation of wood, necessary as preparation for further processing of wood pulp. After the process, the pulp from the cavitator 3 with a temperature of 70-92 ° C is fed into a filter centrifuge 4, for example with a knife discharge of sediment, or into another apparatus that allows you to separate the solid phase from the liquid, for example a separator.

The solid phase (activated wood) is collected in a container 11, and after drying in the apparatus 12, it enters the apparatus 13, where the resin is extracted, which, after distillation of the solvent in the apparatus 15, is removed from the process, and the activated wood is sent to the chemical modification reactor 14. Extraction of DHA from an aqueous solution is carried out in the apparatus 6 with methyl tert-butyl ether. Methyl tert-butyl ether has valuable technological qualities and is cheap. It has a boiling point of 52 ° C, which is favorable for the process, almost does not dissolve water and other polar substances, and dissolves very well organic compounds of medium polarity, which include DHA. It is very important that methyl tert-butyl ether, in contrast to the ether solvents known for this process, such as diethyl ether, dioxane, tetrohydrofuran, poorly forms peroxides and is therefore more preferred in terms of explosion safety. The extract from apparatus 6 enters the separator 7 to separate the organic liquid phase, which is sent for evaporation to vacuum apparatus 8. After vacuum evaporation, DHA is obtained with a yield of 2.2-2.5 wt.%, Calculated on absolutely dry wood with a degree of purity 95% In a preferred embodiment of the method, the organic phase is passed through a sorbent before evaporation, for example, a carbon filter 9, which is a carbon fiber, for example, ASM according to TU 6-16-22-1449-91, or lightening coal, for example, grade ОУ-А GOST 4453- 74 to discolor and remove the accompanying impurities of oligosaccharides, pectins, etc., then evaporated in a vacuum apparatus 8 and further recrystallized from hot water in a crystallizer 10. In this case, DHA is obtained with a yield of 2.2-2.3 wt.%.

The proposed method can be implemented using standard equipment.

Example 1

1000 g of crumb of the butt part of the larch with linear dimensions L × B × H = 4 × 2 × 1 mm with a relative humidity of 10 wt.% Is loaded into a container V = 40 l connected with a cavitator with a power of 30 kW, deionized water is also fed there, the ratio solid and liquid phase is 1:10.

The pulp from the tank 1 through the valve 2 enters the cavitator 3 and then returns to the tank 1. The process is carried out for 5 minutes at a temperature of 92 ° C. After the cavitation process is carried out, the pulp with a temperature of 90 ° C is fed from the cavitator 3 to a filtering centrifuge 4 of the FGN-63P-03 type with knife discharge of sediment. The filtrate is collected in a container 5 and cooled to a temperature of 40 ° C. The extraction of DHA is carried out in the apparatus 6 with methyl tert-butyl ether, taken in an amount of 1.5 liters (V _{water, rust} : V _mtbe = 10: 1). The extraction composition in an amount of 11 l (loss is 0.5 l) from the apparatus 5 enters the separator 7 to separate the organic phase. The organic phase in an amount of 1.4 l is evaporated in a vacuum apparatus 8.

Obtain 22.5 g of DHA composition With ₁₅ H ₁₂ About ₇ , the degree of purity of 95%, yield 2.5 wt.% In terms of the weight of absolutely dry wood.

1000 g of activated wood pulp after drying from water in a drying apparatus 12 with a relative humidity of 10 wt.% Is loaded into an extractor 13, 6 l of methyl tert-butyl ether are fed there and heated for 1 hour at 55 ° C, then the solid phase is filtered off and sent to the chemical processing reactor 14, and the ether extract was evaporated in apparatus 15. Obtain 30 g (3.1%) of natural resin.

10 g of activated wood pulp obtained after cavitation and washing with methyl tert-butyl ether are poured into 100 ml of acetonitrile and 10 g of phosphoric acid hexamethyltriamide are added and heated for 4 hours at 70 ° C. The reaction mass is cooled, the solid phase is filtered off, washed with acetonitrile and dried in vacuum. 15 g of phosphorylated wood are obtained, the phosphorus content of which is 11.4%.

For comparison: 11 grams of phosphorylated wood with 0.76% phosphorus content is obtained from 10 g of sawdust not washed with cavitation washed with methyl tert-butyl ether.

Example 2

5 g of activated wood pulp obtained after cavitation and washing with methyl tert-butyl ether in Example 1 are poured into 10 g of hexamethyldisilosane and heated for 3 hours at 70 ° C. The reaction mass is cooled, the solid phase is filtered off, washed with acetone and dried in vacuum. Get 7.5 g of silylated wood, the silicon content of which is 10.2%.

For comparison: from 5 g of wood pulp washed with methyl tert-butyl ether, which has not undergone cavitation, 5.7 g of silylated wood is obtained, the silicon content of which is 3.1%.

Example 3

10 g of wood pulp obtained after cavitation and washing with methyl tert-butyl ether in Example 1 are poured into 100 ml of acetonitrile, 10 g of monochloracetic acid chloride are added and heated for 3 hours at 60 ° C, blowing dry nitrogen. The reaction mass is cooled, the solid phase is filtered off, washed with acetonitrile and dried in vacuum. Obtain 13.5 g of chlorinated wood, the chlorine content of which is 15.5%.

From 10 g of sawdust not washed with cavitation washed with methyl tert-butyl ether, 11.7 g of chlorinated wood is obtained, the chlorine content of which is 5.1%.

Claims (1)

A method of processing larch wood, including treating degraded larch wood in a fluidized state with deionized water at a wood: deionized water weight ratio of 1: 4 to 1:10, dividing the resulting pulp into liquid and solid phases, separately treating the liquid and solid phases, the solid phase treated with an organic solvent, and the allocation of dihydroquercetin and natural resins, characterized in that the treatment of the degraded wood in a fluidized state is carried out in cavitator at 70 - 92 ° C for 5-15 minutes, the liquid phase is treated with an organic solvent, the solid phase obtained after separation of the pulp is dried before being treated with an organic solvent to a moisture content of 9-11 wt.%, methyl tert-butyl ether is used as an organic solvent the treatment of the solid phase with methyl tert-butyl ether is carried out at 50-55 ° C with the release of natural resins from the resulting solution, and the remaining activated wood pulp is reacted with phosphorylating, silylating or chloracil another agent at 60-70 ° C.