RU2290979C1 - Method for extraction of plant material and apparatus for performing the same - Google Patents

Abstract

FIELD: process and equipment for extracting of soluble substances from dispersion solid phase.

SUBSTANCE: apparatus has extractor and adjustment equipment. Extractor has casing with cover and filtering partition built into cover, bottom and process connection pipes. Apparatus is further provided with reservoirs for extractant and extract and pipeline system for feeding of extractant and discharge of extract. Pipeline system couples said reservoirs with lower and upper parts of extractor for feeding of extractant into lower part of extractor and discharge of extract from upper part of extractor. Hydraulic pulse generator is connected to extractant feeding pipeline. Method involves performing extraction process in flow-through mode; providing liquid pulsation by first feeding of extractant during 2-5 min at frequency of 0.05-0.2 Hz and amplitude of 150-200 mm, then up to the end of extraction process at frequency of 0.5-1.5 Hz and amplitude of 10-30 mm. Method allows extraction time to be reduced by 10 times.

EFFECT: reduced consumption of extractant, enhanced reliability in operation, simplified and convenient maintenance of apparatus, and decreased process time.

3 cl, 1 dwg, 2 tbl, 2 ex

Description

The invention relates to methods for extracting soluble substances from a dispersed solid phase and equipment for its implementation and is intended for use in chemical, pharmaceutical, food and other industries.

Numerous methods are known for isolating biologically active substances from plant materials using extractants (RF application No. 2001115097, 2004, class C 11 B 1/10; Russian Federation patent No. 32150852, 2000, class 11 B 1/10, US Pat. 2124560, 1999, class C 13 D 1/00; US Pat. No. 3,571,892, 1971, class C 13 D 1/00; US Pat. No. 4,857,279, 1989, class C 13 D 1/00, etc. .). The choice of a specific extraction method and the mode of its implementation, as a rule, is determined by the characteristics of the processed raw materials obtained by the target product, as well as the characteristics of the equipment used.

In particular, a method of extraction is known (US Pat. RF No. 2117693, 1997, class C 11 B 1/10) which consists in extracting the material with a solvent to form micelles, followed by their separation by filtration and settling. The disadvantage of this method is the multi-stage, duration and complexity of the process, as well as complex hardware design.

To carry out the extraction, plants of various designs are used, as a rule, containing extractors of various designs, the casing of which is connected to containers for the extractant and the resulting extract (PM RF №12365, 2000, class B 01 D 11/02; PM RF №24396, 2002, CL B 01 D 11/02 Pat. RF No. 2174032, 2001, CL B 01 D 11/02; Pat. RF No. 1491540, 1989, CL B 01 D 11/02).

A device is known for conducting mass transfer processes in heterogeneous systems, comprising a housing equipped with extractor inlet and outlet nozzles, between which there is a layer of the processed dispersed material (Planovsky A.I., Nikolaev P.I. The main processes and apparatuses of chemical and petrochemical technology. M. : Chemistry, 1987 fig. 15.4.a, p. 372).

The disadvantages of the known device is the possibility of channel formation in the processed material, which leads to an increase in the extraction time and a reduction in the contact surface of the phases, a significant diffusion resistance in the boundary layer, which reduces the efficiency of mass transfer processes.

The most promising from the point of view of mass transfer are methods associated with periodic or continuous mixing of the extracted plant material, for example, using a mixer (US Pat. RF No. 2091121, 1997, CL B 01 D 11/02) or ultrasonic vibrations (US Pat. RF No. 2053006, 1996, CL B 01 D 11/02; Pat. RF No. 2127752, 1999, CL C 11 B 11/02). The extraction plants used in this case are characterized by the installation of appropriate devices in the extractor.

The disadvantage of these extraction methods and the installations used is the lack of efficiency due to the insufficiently high sorption of biologically active substances from the plant surface, as well as the possibility of channel formation in the processed material, which affects the efficiency of the process.

Closest to the claimed solution is the extraction unit and the extraction method (US Pat. RF No. 2142314, MKI B 01 D 11/02, 1999), previously developed by the authors.

The installation contains a pulsating batch extractor, containers for extractant and extract, as well as a piping system for supplying extractant and extracting the extract with control equipment. The extractor contains a cylindrical body with a lid containing a filter baffle built into it, a bottom, technological fittings and a pulsation chamber made in the form of a bell located coaxially in the body, and a device for turning it 180 °.

The method consists in the fact that after loading the raw materials in a pulsation chamber, alternating pressure is created, as a result of which the suspension of plant materials in the extractant comes in a reciprocating motion, due to which the concentration of the extracted biologically active substances in the volume of the extractor is equalized and the extraction process is possible until equilibrium is reached values. Then the extractant is removed, the apparatus is turned over, a new extractant is introduced and the process continues in a similar manner.

The disadvantages of this extractor are large overall dimensions, a large amount of extractant required for complete depletion of raw materials. The disadvantages of the method are the necessity of carrying out the process in several stages, non-optimal conditions for conducting the mass transfer process, since the maximum difference in the concentrations of extractable substances in the solid and liquid is not created.

The problem to be solved within the framework of the claimed group of inventions was the creation of a more efficient and more compact extraction unit and the implementation on its basis of the extraction method under optimal conditions of mass transfer.

The technical task of the claimed group of inventions is the creation of an installation and an extraction method, using which extraction is carried out from raw materials, the surface of which is subjected to continuous cleaning of extractable substances, which ensures the most efficient mass transfer of substances.

The technical result in relation to the device is achieved by introducing into the installation of a hydraulic pulse generator, which is able in one mode of operation to squeeze the raw materials in the upper part of the extractor, which eliminates channel formation, and to ensure maximum efficiency of the use of the extractant, and in the other to create a “squeezed” vibration a layer that provides shaking from particles of raw materials of the surface layer of the extractant containing the extracted substances. Those. the generator, unlike the pulsator used in the prototype, does not mix the particles of raw materials, but stabilizes their presence in the extractor. The composition of the installation, in contrast to the analogue, includes containers for extractant and extract and a piping system for supplying extractant and extracting the extract, connecting these containers with the lower and upper parts of the extractor to supply extractant to the lower part of the extractor and extracting the extract from the upper part of the extractor, and to the pipeline a hydraulic pulse generator is connected to supply the extractant.

An additional technical result is achieved by using a circuit that allows regularly, instead of supplying the extractant in a pulsed mode, from bottom to top to apply it from top to bottom, providing cleaning of the upper filter partition of the extractor. Such a scheme includes the installation of an additional filtration partition in the lower part of the extractor, wherein the extractant supply pipe connects the top of the extractor to the extractant container, and the extract pipe connects the bottom of the extractor to the extract collection tank, and the pipelines for supplying extractant and extract extract equipped with control equipment (valves or gates), providing a change in the direction of flow in the extractor.

The technical result in relation to the method lies in the fact that the extraction process is carried out in a flow mode, and the pulsation of the liquid is carried out by feeding the extractant first for 2-5 minutes with a frequency of 0.05-0.2 Hz and an amplitude of 150-200 mm, and then until the end of the process extraction with a frequency of 0.5-1.5 Hz with an amplitude of 10-30 mm.

At the first stage, as a result of this action, it is possible to concentrate the crushed vegetable raw materials in the upper part of the body in the form of a homogeneous dense mass to eliminate channel formation, and at the second stage (in the operating mode), along with maintaining the plant particles in the clamped state, it is possible to bring them into a vibration state, providing intensive desorption of the extractant from the surface of these particles. Because the extractant is then removed from the extractor, then the equilibrium state is not achieved until a predetermined degree of extraction is achieved.

The general installation diagram is shown in the drawing. The installation consists of a container for extractant (EEG) 1, an extractor (ER) 2, a container for extractant (EET) 3, as well as a pump combined with a pulse generator (GI) 4. The extractor consists of a cylindrical body 5 with a cover 6 containing a built-in filtering partition (FP) 7 into it, bottoms 8 with filtering partition (FP) 9, and technological fittings connecting ER 2 with supply (PT) 10 and discharge (OT) 11 trunk pipelines. ER 2 contains raw materials for extraction 12. At PT 10 are placed control devices (RU) - valves or gates - RU 13 and RU 14, from OT 11 -RU 15 and RU 16.

The installation may consist of the above fragments or have additional elements that perform independent functions, or may not have a part of elements of secondary importance, for example, a set of fragments of military units 10 and 10 OT 11 and RU 14 and 15.

Installation works as follows. Raw materials 12 are placed in the housing 5 ER 2, if necessary, turn on the heating jacket ER 2 and serves the extractant from the EEG 1 in the area abv Fri 10 through RU 13 and FP 9 into the housing.

After filling the casing 5, turn on GI 4, which in a pre-calculated mode delivers a hydraulic impulse tightly pressing the raw material 12 to the FP 7. In the "pressing the raw material layer" mode, there are no free channels in the layer and uniform passage of the extractant through the raw material.

Upon transition to the operating mode, a constant “shaking” of particles occurs, which provides better conditions for the release of raw material particles from the layer of extractant sorbed on their surface containing the extracted substances. Next, the extract through FP 7 enters the area where OT 11, and then in EET 3 and then to concentration. When working with technologically complex raw materials (high dispersion, increased adhesion, etc.), it becomes possible to clog FP 7. To prevent this, periodically close RU 13 and RU 16, opening RU 14 and RU 15. In this case, the extract comes from EEG 1 through section abg ПТ 10 and further through FP 7 and FP 9 along the section vd OT 11 to ЕЭТ 3. Hydraulic impulses from ГИ 4, on the one hand, clear ФП 7, and on the other hand, provide “preload” of raw materials to ФП 9 and efficient extraction .

Features of the use of the invention are illustrated by the following examples.

Example 1. On the inventive installation for producing extractive substances in an extractor equipped with filter baffles and a heat exchange jacket, experiments were carried out to extract ginseng 24% ethanol in water with varying parameters of the extraction process at a temperature of 50 ± 5 ° C. 25 kg of chopped plant material were loaded into the extractor. Evaluation of the effectiveness of the process was carried out by the concentration of extractable substances in the exhaust extractant.

The results are shown in tables 1 and 2.

Table 1
The effect of pre-clamping the layer on the extraction rate of biologically active substances in the system of crushed ginseng root: 24% solution of ethanol in water at 50 ° C. Extraction time, min Pulsation frequency, Hz The concentration of biologically active substances kg / kg after 60 min Amplitude, 100 mm Amplitude, 150 mm Amplitude, 200 mm 2 0.05 0.34 1.0 0.36 2.0 0.37 four 0.05 0.36 0.43 0.43 1.0 0.42 0.43 0.43 2.0 0.43 0.43 0.44 5 0.05 0.39 0.42 0.43 1.0 0.43 0.43 0.44 2.0 0.44 0.43 0.44 8 0.05 0.40 0.44 0.44 1.0 0.43 0.44 0.44 2.0 0.44 0.44 0.44

As the results of the experiments showed, it is optimal to use a frequency of 1 Hz with an amplitude of 100 mm for at least 4 minutes. Further tightening of the clamping mode of the layer does not affect the speed of the extraction process. The weakening of these conditions leads to a decrease in the rate of extraction.

Table 2.
The influence of process parameters on the rate of extraction of biologically active substances in the system crushed ginseng root: 24% solution of ethanol in water at 50 ° C. Extraction time, min Pulsation frequency, Hz Amplitude, mm
The concentration of biologically active substances kg / kg Amplitude, 10 mm Amplitude, 30 mm Amplitude, 100 mm 7.5 one 0.015 0.028 0.028 fifteen 0.024 0.033 0.034 thirty 0.029 0.038 0.039 60 0.036 0.044 0.046 120 0.040 0.048 0.050 240 0.043 0.051 0.053 7.5 0.5 0.27 1.0 0.28 1.5 030 60 0.5 0.43 1.0 0.43 1.5 0.43 240 0.5 0.49 1.0 0.52 1.5 0.52 480 0.5 0.54 1.0 0.54 1.5 0.54

Thus, the pulsation frequency at 0.5-1.5 Hz practically does not affect the extraction rate at further stages of extraction. In this case, the extraction rate increases with increasing amplitude to 20 mm, a further increase in amplitude does not significantly affect the extraction rate.

Example 2. Extraction of licorice root to obtain the sum of extractive substances was carried out in an extractor equipped with filter baffles and a heat exchange jacket. A 5% aqueous-alcoholic solution with a temperature of 50 ± 5 ° C was used as an extractant. 25 kg of chopped plant material were loaded into the extractor. From the container for the extractant, the extractant is continuously fed into the extractor for 5 minutes in a pulsating mode with a frequency of 0.1 Hz and an amplitude of 175 mm, and then until the end of extraction with a frequency of 1 Hz and an amplitude of 20 mm.

The extraction time is 30 min, the yield of extractives is 8.6 wt.%, The extractant consumption is 13.1 l / kg. When using the analog process under the same conditions (US Pat. RF No. 2142314), the following results were obtained: extraction time 330 min, yield of extractives 8.1 wt.%, Extractant consumption 15.0 l / kg. According to the traditional extraction scheme, the maximum yield of extractives is 2 wt.%.

As follows from the above data, the extraction in the present mode on this unit allows you to almost 10 times reduce the extraction time, reduce the consumption of extractant, increase the yield of extraction products.

Claims (3)

1. An extraction installation consisting of an extractor and control equipment, the extractor comprising a housing with a lid with a built-in filter baffle, a bottom and technological fittings, characterized in that it further comprises containers for extractant and extract, a piping system for supplying extractant and discharge extract connecting these containers with the lower and upper parts of the extractor for feeding the extractant to the lower part of the extractor and draining the extract from the upper part of the extractor, and to the pipeline for I supply extractant connected to a hydraulic pulse generator. 2. The extraction installation according to claim 1, characterized in that in the lower part of the extractor an additional filtration partition is installed, while the pipeline for supplying extractant connects the top of the extractor to the container for the extractant, and the pipeline for draining the extract connects the bottom of the extractor to the container for collecting the extract, moreover, the pipelines for supplying extractant and extracting the extract are equipped with control equipment that provides a change in the direction of flow in the extractor. 3. The extraction method, which includes the interaction of the extractant with plant material in a pulsating mode, characterized in that the extraction process is carried out in a flow mode, and the pulsation of the liquid is carried out by feeding the extractant first for 2-5 minutes with a frequency of 0.05-0 , 2 Hz and an amplitude of 150-200 mm, and then until the end of extraction with a frequency of 0.5-1.5 Hz at an amplitude of 10-30 mm.