Peat extraction method and apparatus

The subject of the invention is a peat extraction method and a peat extraction device.

Polish patents Nos. 1 ^^ 4110 and 125 769 describe peat treatment methods that lead to the isolation of biologically active substances by eluting air-dried peat with an aqueous alkali solution. Due to the strong sorption properties of peat, the leaching operation is extremely difficult to perform on a technical scale.

Attempts to apply the static method when extracting large batches of peat raw material did not bring a satisfactory result. The static method is commonly used for the extraction of raw materials whose structure and degree of fragmentation allow the permeate to penetrate freely into the raw material in the entire volume of the extracted bed and consists of flooding the raw material with solvent, leaving the extractant in contact with the raw material until the concentration is equalized and collecting the extract from the bottom of the extractor so that the flowing extract washed out the desired substances from the whole mass of the raw material. If this technique is applied to air-dried peat, it is not possible to collect the extract from the bottom of the extractor due to the formation of an impermeable layer of silt and sludge in the lower parts of the extractor as a result of sedimentation of swollen peat particles.

167 664

For the same reasons, flooding the projection of peat with a solvent in extraction tubs and periodically mixing the whole, followed by decanting the obtained extract from the peat layer, proved equally ineffective. Under such conditions, the penetration of solvent in peat is negligible, because the longer the time of contact of the solvent with peat, the more extensive is the impermeable sludge layer formed in the bottom of the extraction tub. The result of decantation is a relatively clear extract, but with a very low concentration of desired substances.

Increasing the intensity of mixing increases the penetration of the solvent in the peat bed but at the same time disperses the sludge layer and prevents the extraction of a clear extract layer above the peat bed and separation by decantation. Sedimentation and swelling of sedimenting peat particles also causes a number of side technical problems in the discharge phase of the extraction tubs and cleaning them before proceeding to the next extraction cycle. The situation does not improve regardless of whether the peat raw material is filled into empty extraction baths, into which solvent is then introduced, or whether the order of introducing solvent and peat into the baths is reversed, i.e. the bath is filled with solvent first, and then the peat raw material is introduced . In addition, the desired active substances diffuse into the solvent only from the upper layers of the peat bed, which is the reason for the relatively low efficiency of the extraction process. The desired substances contained in the deeper layers of the peat deposit do not go into solution and are lost in the rejected parts of the extraction peat.

The purpose of the present invention is to develop a convenient and effective method for the extraction of peat resulting in clear extracts that are both free from solid particles and rich in extracted desired substances. A further object is to develop a suitable device for carrying out the extraction according to the invention. In addition, it is an object of the invention to provide preferred embodiments of the invention.

According to the invention, the extractant, preferably at room temperature and only slightly elevated pressure, is introduced into the extractor from below and passed through an air bed of dry peat at a pressure sufficient to force the solvent to flow freely through the bed. The extract is collected from above the peat layer, from the top of the extractor to obtain a solution free from solid particles. Preferably, the extract obtained is recirculated at least twice and passed through a peat bed under substantially the same conditions as described above.

The extractant used according to the invention is inorganic solvents such as preferably water and / or aqueous lye solutions, such as 0.2-0.7% aqueous sodium hydroxide solutions. Although, for economic reasons, extraction according to the invention is carried out at ambient temperature, even as low as + 4 ° C, the method according to the invention can also be carried out at higher temperatures selected according to the specific purposes to be carried out in the extraction process.

It is also possible to carry out the extraction according to the invention using organic solvents such as alcohols, higher molecular weight ethers, esters and the like organic extractants, preferably ethyl alcohol.

The desired degree of extraction of the raw material is achieved in accordance with the present invention using a fresh batch of solvent in the second phase of extraction, wherein both in the first and second phase of extraction the extracts are recirculated and are passed through the bed of extracted raw material several times.

The essence of the process of the invention is the use of a continuous flow of solvent or recirculated extract through the bed from the bottom to the top layers of the bed of peat particles. As a result, the peat particles are suspended in the extractant stream flowing from the bottom up, and at the same time are not entrained by this stream. Under these conditions, the extractant penetrates the entire peat bed and washes every single particle of raw material. This means that the desired substances are washed out evenly from the entire peat bed. The time of interaction of the extractant on the peat raw material particles is regulated both by regulating the flow rate and by the recirculation times of the obtained extracts through the peat bed. The final extract obtained by the process of the invention is free of solid peat particles, which eliminates the need for filtration before further processing of the extract.

167 664

The unexpected effect is achieved by balancing the gravitational sedimentation rate of peat particles and the speed of displacement of the extractant flowing in the opposite direction. If these parameters are not perfectly synchronized, the peat particles either sediment or are carried along with the extract stream to further elements of the extraction plant. Hence, laminar flow of extractant through the peat bed is required.

The required flow rate of the liquid phase depends on the size of the peat particles and the pressure at which the extractant is fed, which in turn is a function of the height of the peat bed in the extractor. At the same time, the amount of liquid introduced into the extractor depends on its diameter and its capacity.

When the process is started, the peat bed first loosens under the influence of the extractant pressure, so that each peat particle is washed from all sides by the liquid phase. No agglomeration or channel formation is observed in the peat bed through which liquid could flow freely bypassing larger agglomerates of peat particles. Thanks to this, each peat particle is extracted under the same conditions regardless of whether it is located in the upper or lower part of the bed.

The invention brings numerous benefits, among which the most important are: almost complete leaching of the desired biologically active substances from the peat raw material, reduction of the volume of the extract and the use of the extractant in comparison with the existing extraction methods, facilitating the process of extract thickening in further stages of extract processing, significant energy savings and technical media. In addition, in a preferred embodiment of the invention, when using aqueous sodium hydroxide as the extraction solvent, due to the use of the present method in the subsequent stages of peat extract processing, smaller volumes of this solvent are subjected to a neutralization reaction, which significantly reduces the salinity of the final product.

The invention also relates to a peat extraction device, which is an extraction battery, comprising at least one storage tank for the extraction agent, at least one extractor and at least one circulation tank for collecting the extraction agent enriched with extracted substances, supply pipelines with pumps mounted on them, leading from the storage tank and from the extractor, and pipelines receiving the extract from the top of each extractor leading to the cooperating circulation tank.

Preferably, at least two extractor assemblies - a recycle tank, extractant tank and final extract tank are connected in accordance with the invention by a piping system enabling pumping liquid from each tank to all other tanks and extractors forming the battery. The extractors are equipped with an extractant supply from the bottom and an extract drainage at the top of the extractor, respectively below and above the peat deposit. Preferably, the liquid circulation in the battery according to the invention is forced and the battery is adapted to work with feeding the extractant under pressure, with stepless control of the pump capacity.

Preferably, the battery according to the invention comprises three extractor assemblies - a recycle tank operating periodically in two stages.

The use of the battery system in the device according to the invention allows for semi-continuous operation of the installation with periodic collection of the final, full-fledged extract at constant, predetermined time intervals, which in turn ensures the rhythm of supplying the installation for further processing of the extract (not covered by the present invention) and rhythmic operation of production lines.

The invention is illustrated in more detail in the scope of the extraction method in the following examples.

Example I. In a semi-technical scale device comprising two glass tanks with a capacity of 200 liters each and a screw dosing pump with stepless capacity control, one tank acted as an extractor and the other - as a circulation tank. 90 kg of air dry peat, previously ground and sieved, was loaded into the extractor so that the peat particle size was between 8 and 30 mm. By means of a dosing pump, 300 kg of 0.35% by weight aqueous sodium hydroxide solution was introduced into the extractor from below, below the peat bed, in about 120 minutes. When the volume of the extractor was completely filled, the excess liquid flowed into the adjacent circulation tank through the drain located above the peat bed. Then a closed circulation loop was used

167 664

- Z3 circulation tank with the extractant passing the bed several times. Peat bed in the E2 extractor, which at the stage shown in Fig. 2b has already been extracted once, it is now treated with fresh lye solution LO, which after passing through this bed is directed to the Z2 circulation tank, from where the enriched L2 alkaline extract is removed (after passing through two peat deposits), directing it towards A, for the installation of further processing of the extract, such as neutralization and desalting.

Figure 2d: The bed in the E2 extractor is washed with WO water collected in the Z2 circulation tank. The extracted peat bed is removed (arrow B). Water W1 from the Z2 circulation tank containing the extract residues washed out of the peat bed is directed to the fresh peat bed to the El extractor, from where it is directed as the W2 stream to the Z1 circulation tank and possibly circulated in the El extractor system - the Z1 circulation tank with several passes through peat deposit. At the same time, the peat bed in the E3 extractor, which has already been extracted (Figure 2c), is mixed with fresh lye solution LO, which - if appropriate after recirculation through the bed several times - is directed from the Z3 tank towards A for further processing.

Figure 2e: The peat bed in the E1 extractor, which was already in the phase shown in Figure 2d, pre-extracted with water W1 / W2, is now extracted with fresh lye solution LO, which is drained - after proper recirculation - from the Z1 tank in the A direction for further processing. At the same time, the WO water is directed to an almost completely extracted peat bed in the E3 extractor and after washing the remaining residue from the bed, as W1 it is directed through the Z3 circulation tank to the fresh peat bed in the E2 extractor, while removing the extracted peat bed from the E3 extractor towards B. Water extract W2 from extractor E3 - after recirculation through the Z2 circulation tank and battery operation is continued as in the stage shown in Fig. 2c.

The invention is not limited to the embodiments described above; and so: the pre-extraction can also be carried out with a lye solution, optionally a diluted lye solution and not water as shown in the above examples; extraction with water and extraction with a liquor solution can be carried out alternatively; finally, if the procedure were limited only to switching valves, the extraction process could be carried out in a continuous way by directing the extraction solution in countercurrent to subsequent portions of fresh peat through several extractors, with the disconnection of the extractor with the most extracted peat bed, emptying it, refilling it and including as opposite fire extreme extractors.

Immunomodulatory and anti-cancer properties of peat extracts.

Peat extracts have already proved effective in the treatment of the following diseases: periodontosis, cancer and precancerous diseases, autoallergic diseases (e.g. sclerosis multiplex), allergic diseases (e.g. asthma or dermatitis), various infectious diseases (e.g. influenza), brain and nervous system cancers (glioma, astraeyloma), breast cancer (carcinoma), cancer bones and soft parts (mainly sarcoma), leukemia (acute and chronic) lymphatic and myeloid leukemia, lymphoma (lymphoma), Hodgkin's disease, head and neck cancer, cancer of the bile duct, liver and pancreas (carcinoma, adenocarcinoma), tumors of the stomach, small intestine, colon and anus (carcinoma and adenocarcinoma), kidney cancer (carcinoma microcellulare, Wilms tumor), prostate cancer (adenocarcinoma), testicular cancer (carcinoma, teratoma, chorio-epithelioma), cancer bladder (carcinoma), tumors of the female reproductive organs (carcinoma, adenocarcinoma), cancers in children (Wilms tumor, neuroblastoma, ganglioma).

167 664 extract between the circulation tank and peat bed extractor. The extract was rolled about eight times, with the metering pump capacity set at around 1000 liters per hour. At this pump capacity, the peat particles remained suspended in the extractant stream and neither sedimentation nor aggregation of the peat particles was observed. No formation of an impermeable sludge layer was observed in the lower parts of the peat deposit. At the same time, the peat particles did not leave the bed, were not entrained by the flowing liquid phase or transferred with it to the circulating tank. 1751 clear extract was collected. The color of the extract was golden yellow, which indicated a high concentration of substances extracted from peat.

Depending on the origin of the peat, the extract may contain the following substances: cellulose, hemicellulose, free amino acid proteins, resins, waxes, humic acids and their salts, sulfoacids, lignin, hymatomelate acids, other organic acids, enzymes and other substances.

Example. The procedure described in Example 1 was repeated on a technical scale.

1000 kg of air-dried peat was introduced into the extractor. Then 3000 kg of a 0.35% by weight sodium hydroxide solution was introduced into this extractor through the bottom feed. The solvent flowed through the peat bed without entraining - on the one hand - peat particles but at the same time not allowing their aggregation and sedimentation in the lower parts of the bed - on the other hand. The overflow end located above the peat deposit in the extractor was taken to the circulation tank. A dosing pump adapted to feeding 2-8 m was used to feed the extractant to the extractor³ liquid per hour. The pump worked with a capacity of 50 kg liquid / minute. As soon as the entire 3000 kg of lye solution was introduced into the system, the recirculation of the extract was started to accelerate the extraction process. The extraction agent was passed through the peat bed about eight times in about 8 hours. The obtained extract was collected and pumped into a handling tank by displacing it from the extractor with fresh solvent (again it was a 0.35% by weight sodium hydroxide solution). A second crop of extract was obtained by recirculating a second portion of solvent under the same conditions as described above for the first extraction step.

The extract obtained in the second extraction step was used as an extraction agent for the next fresh batch of peat subjected to extraction as described above in relation to the first extraction step.

The invention in the scope of the device is described in more detail below, based on the attached drawings, in which Fig. 1 schematically shows all extractors and battery tanks as well as the connection system between them (including valves) and Fig. 2 schematically illustrates a possible operation system extraction battery according to the invention.

Example III. 1000 kg of fresh ground air-dried peat are introduced into each of the three extractors El, E2 and E3 (Figure 1).

a) Using a P1 pump, 3000 kg 0.35% by weight of sodium hydroxide solution is pumped through the E1 extractor with a drain to the Z1 circulation tank; valve VI open.

b) (Optional): Using the P1 pump, the initial alkaline extract from the Z1 circulation tank is pumped again through the El extractor - possibly several times; valves V3 and V4 open.

c) With the help of the P2 pump, the alkaline extract obtained in the E1 extractor is pumped - possibly partially - to the installation for further processing of the extract (arrow A); valves V4 and V22 open.

d) Using the P1 pump, after a possible discharge of some of the alkaline extract for further processing, make up the defect with fresh lye solution; valve VI open.

The other sets of E2 extractor - Z2 circulation tank and E3 extractor - Z3 circulation tank are started in an analogous manner, possibly simultaneously with the operations described above carried out in the E1 extractor - Z1 circulation tank.

Example IV

a) The procedure described in Example 3, step a) is repeated.

b) Using pump P3, the alkaline extract is pumped from the Z1 circulation tank through the E2 extractor to the Z2 circulation tank; valves V5, V18 and V8 open.

167 664

c) With the help of the P3 pump, the enriched alkaline extract is pumped to the plant for further processing of the extract (arrow A); valves V9 and V23 open. At the same time, with the help of pump P1, fresh liquor solution is pumped through extractor E3 with overflow to the Z3 circulation tank; valve V11 open.

d) With the help of the P2 pump, the alkaline extract after passing through the peat bed in the E3 extractor, extracted with one portion of lye, is pumped to the El extractor with an overflow to the Z1 circulation tank; valves V15, V17 and V3 open. The extracted peat is removed from the E2 extractor through valve V7 in the direction of arrow B.

e) The E2 extractor is loaded with the next batch of peat and the cycle is repeated again starting from point b) above.

Example V. A certain point in time was selected during a flashing battery life. In this phase:

The E1 extractor contains a peat bed through which a batch of enriched extract with a high concentration of extracted substances has already passed, followed by a batch of initial alkaline extract with a lower content of substances extracted from peat. At present, fresh lye solution flows through this bed to wash out the residue of the extract before replacing the bed with a new bed of peat raw material.

The E2 extractor contains a peat deposit through which a batch of enriched extract with a high concentration of extracted substances has once been. The lye solution containing certain amounts of the extract, which had previously passed through the El extractor, now flows through the E2 extractor, followed by a fresh liquor solution.

The E3 extractor contains a fresh peat bed, through which flows an enriched extract with a high concentration of extracted substances that has previously passed through the peat bed in the E2 extractor. Then the solution (originally a fresh lye solution) mentioned above when discussing the situation in the E2 extractor and now containing some amounts of extracted substances, passes through the peat bed in the E3 extractor.

An alkaline solution that has already passed twice through another peat deposit flows through another peat freshly introduced into the battery; an alkaline solution that has only once passed through another peat bed, then flows through the bed through which the fresh lye solution finally flows.

After such three passes, the post-extractive peat is removed from the battery in the direction of arrow B, and the extractor - if necessary - is cleaned and loaded with a fresh batch of peat. Each extract that has passed through three successive beds is pumped for further processing or discharged in the direction of arrow A (Figure 1). The cyclical battery operation is also possible with four or even more extractor-circulating tank assemblies.

Example VI. As shown in Figure 2, another battery operation system according to the invention, consisting of three extractors E1, E2 and E3 and three circulation tanks Z1, Z2 and Z3, is also possible. In this case, the process takes place in three cycles (2c, 2d and 2e) after the battery activation phase of two cycles (2a and 2b).

Figure 2a: fresh lye solution LO flows through the peat bed in the E1 extractor to the Z1 circulation tank and, if appropriate, the solution is circulated in a closed system, the E1 extractor, the Z1 circulation tank, with the extractant passing the bed several times.

Figure 2b: The L1 extract from the E1 extractor is directed through the Z1 circulation tank to the Z2 extractor, in which there is a fresh peat bed, and then after passing through this bed as the L2 extract to the Z2 circulation tank. In a closed system, the E2 extractor - Z2 circulation tank, is followed by circulation of the solution with the extractor passing several times through the bed. At the same time, a partially extracted peat bed in the E1 extractor is treated with another batch of fresh lye solution LO, which is also optionally subjected, after passing through the bed to the Z1 circulation tank, to circulate in a closed system the E1 extractor - Z1 circulation tank.

Figure 2c: WO water is directed through the extracted peat bed in the E1 extractor to the Z1 circulation tank. The water-washed peat bed is removed from the E1 extractor (arrow B). Water W1 from the Z1 circulation tank containing the residue of the extract washed out of the peat bed, is directed to the fresh peat bed to the E3 extractor and to the Z3 circulation tank, after which - if necessary, circulation of the closed E3 extractor takes place

<img file="PL167664B1_D0001.tif" />

Fig.2

<img file="PL167664B1_D0002.tif" />

UP Department of Publications. Circulation of 90 copies Price PLN 150