WO2007132003A1

WO2007132003A1 - Method for removal of germination and propagation capacity of animal- and plant-based organisms, and arrangement for implementing the method

Info

Publication number: WO2007132003A1
Application number: PCT/EP2007/054697
Authority: WO
Inventors: Werner Hartmann; Armin Schütz
Original assignee: Siemens Aktiengesellschaft
Priority date: 2006-05-15
Filing date: 2007-05-15
Publication date: 2007-11-22
Also published as: DE102006022611A1

Abstract

Many bulk goods contain organic impurities that are unwanted. According to the invention, electrical fields are used for removal of the seeding and propagation capability and of the damage potential of these impurities. The germinating cells in the seeds present can thus be denatured and their germination capacity removed, or the propagation or reproductive capacity of biological contamination or of insect pests can also be destroyed. For this purpose, an arrangement is provided consisting of two electrodes (102, 103) between which the material to be treated (5, 6) flows, wherein the electrodes are controlled by an electrical unit (101) for generating voltage pulses.

Description

description

Method for eliminating the germination and reproductive performance of animal and plant organisms and the procedure for carrying out the method

The invention relates to a method for eliminating the germination and propagation ability as well as the damage potential of organisms, in particular of animal and vegetable organic admixtures in bulk solids and / or intermediate or end products formed therefrom. In addition, the invention also relates to an associated arrangement for carrying out the method.

In the production of compost, floral and plant soil, cattle mulch od. Like. , but also in agricultural production - seeds; Cereals, maize, etc. for food - always get unwanted seeds from Beikrautern, microorganisms and u. U. unwanted microorganisms such. B. fres- sende pest insects in the final product, which also by proper management of the processing processes such. B. the rotting do not lose their germination or reproductive ability. When the product is brought out, these seeds can germinate or multiply in the unwanted organisms and small creatures. This leads u. a. to an undesirable growth with sometimes very difficult to eliminate unwanted plants such. As thistles, stinging nettles, plantain, yaw, dandelion, etc., as well as the distribution of atypical species and possibly pests. In the seed and food sector, this can lead to high losses due to insect feeding and / or contamination.

Previous solutions are carried out either chemically via admixture of z. As weed killers or insecticides or biocides (fungicides), which can not be used in organic horticulture, or preferably by heating to temperatures in the range of typically about 70 ° C. In particular, thermal processes, for. B. via supply of superheated steam, However, lead to a disadvantageous consistency of the product (clumping) and require a lot of energy.

Irradiation with ionizing radiation (gamma rays, X-ray radiation, electron beams, UV radiation) is possible in principle, but requires extremely high radiation doses in the range> 25 kGy. However, since the seminal or living biological fraction (eg pest insects) has only a negligible mass fraction, especially in the case of compost and plant soil production, these processes are uneconomical and, because of the high radiation exposure, i. a. only used in seed production.

Furthermore, from DE 699 23 912 T2 a method is known, according to which pumpable products are pumped into a treatment chamber in order to treat them there with pulsed electric fields of high amplitude of typically 30 kV / cm and more in order to produce in the products Disable contained microorganisms. By contrast, from DE 100 14 289 A1 a method is known that disinfects other substances and articles by applying electric fields for a short time, i. acting on an intermittent or continuous basis. This particular microorganisms or microorganisms are killed or made incapable of reproduction. Finally, according to JP 2002-253644 A thermal plasmas ("high voltage streamer discharge"), which are generated by pulsed electric fields of high amplitude, used in particular to sterilize seeds or seeds, ie the adhering microorganisms such as bacteria and Remove fungal cells and spores.

In contrast, the present invention seeks to propose an economical method for preventing the germination of plant seeds in compost or potting soil and, alternatively, to eliminate insect pests in seeds and grains, in particular, no burden of ionizing radiation or very high-energy electrical Fields occurs. For this purpose, an associated arrangement should be created.

The object is achieved according to the invention by the measures of patent claim 1. An associated arrangement results from the features of claim 11. Further developments of the method and the associated device are the subject of the dependent claims.

In the solution according to the invention pulsed electric fields are used to denature the germ cells in the existing seeds and thus to eliminate their germination and, analogously, to destroy the reproductive ability of other biological contaminants etc. For this method, electric fields in the range of about 0.5 kV / cm to about 10 kV / cm are suitable. Particularly suitable are electric fields in the range of about 1 kV / cm to about 6 kV / cm at pulse durations (pulse widths) from a few microseconds to tens of microseconds in the range low field strengths and pulse durations from tenth microseconds to a few microseconds at field strengths in the field of several kV / cm.

The action of high electric fields on biological cell systems is known per se under the name "electroporation" and will be particularly evident in the processing of agricultural products, for example sugar beet, potatoes, carrots, corn, apple or the like This is evident, for example, from the publications by C. Schultheiss et al., "Operation of 20 Hz Marx generators on a common electrolytic load in an electroporation chamber", Proc. IEEE Pulsed Power Conference 2003, pages 669 ff. And by H. Bluhm et al. , "Industrial scale treatment of biological cells with pulsed electric fields", Proc IEEE Power Modulator Conference 2004, pages 8 ff. From the latter developments it is also known that electric fields act on plant cells in such a way that with sufficient amplitude and time duration the cell walls are destroyed and thus the cell contents become extractable. In these methods, in addition to the use of whole crops in a water bath with homogenized cell associations (shredded, ground), which are optionally treated with water to a mechanically fordable consistency worked. Other known methods are being investigated or applied in the field of the beverage industry for reducing the germ count of pathogenic bacteria in fruit juices, milk products or the like. This is evident from the publications of JR Beveridge et al. , "Pulsed electric field inactivation of spoilage microorganisms in alcoholic beverages and the influence of pulse profile", Proc. IEEE Pulsed Power Conference 2003, pages 1132 et seq., By JR Beveridge et al., "The Influence of Pulse Duration of monopolar and bipolar profiles pulsed electric fields on the inactivation of Obesumbacterium proteus - a spoilage microorganism ", Proc. IEEE Power Modulator Conference 2004, pp. 615, by K. Wall et al., "Evidence of nuclear membrane damage in yeast cells treated with pulsed electric fields," Proc. IEEE Power Modulator Conference 2004, pp. 623 et seq., And by Timoshkin, IV, et al., "Dynamics of the development of an electrical field across cellular mem- branes - PEF inactivation of micro-organisms ", Proc. IEEE Power Modulator Conference 2004, pages 611 ff.

However, the latter method is not yet known for eliminating the reproductive ability of macroscopic plant and animal cell clusters, especially in bulk materials, in particular those of plant seeds and pest insects, with the aim of selectively eliminating their germination or reproductive and breeding capacity. For this purpose, the debris to be sterilized, such as compost, soil, or the like, is guided through an electrode system, to which intermittent high-voltage pulses of sufficient amplitude are supplied. The high voltage pulses are generated by a high voltage pulse generator with voltage amplitudes of tens of kilovolts and Current amplitudes of a few hundred A to a few tens of kA at pulse repetition rates of typically a few hertz to some 10 Hz generated. Accordingly, adaptation of pulse shape or amplitude, pulse rate and number in biological (eg pest insects, plant seeds, sprouts and parts of plants) and other higher organisms can cause cell damage in such a way that the reproductive ability of such life forms is irreversible disturbed and thus their proliferation and spread is prevented.

In the invention, it is particularly advantageous that only a small amount of energy is needed in comparison to known thermal processes, so that the process according to the invention is economically feasible. The method according to the invention is equally harmless both ecologically and biochemically, since in particular no ionizing radiation is used. Furthermore, because of the low field strengths used, which are typically less than 10 kV / cm, no plasma discharges are generated in the process, so that no ozone is generated and as a result no further measures are necessary for ozone removal.

A further advantage is that, starting from the laboratory scale, the method according to the invention is scalable and can also be controlled in practical operation. Moreover, it is easy to incorporate into existing production processes, since only small space is required for an arrangement according to the invention. In particular, no chemical substances are used as additives and there is no storage of the necessary additives for treatment necessary. When treating a finished product, in particular, there are no changes in the consistency of the finished product.

Further details and advantages of the invention will become apparent from the following description of exemplary embodiments with reference to the drawings in conjunction with the claims. Show it 1 shows a treatment line with continuous supply of a bulk material and Figure 2 shows a treatment line with a semi-continuous

Supply of an intermediate or end product.

In many bulk materials or intermediate and end products from such Gutern organic admixtures are present that multiply during prolonged storage. Prior to the intended use of such debris, intermediate products or end products, sterilization must be carried out.

In the new method is now to be sterilized Good, such. B. rotted compost or soil, acted upon by an electrode system with high electric fields. To the required high field strengths from a few tenths of kV / cm to a few tens of kV / cm in the biological system, z. As a seed to produce itself, a temporary compaction of the product is necessary; otherwise the electric field was predominantly in the range of hollow spaces, i. Air entrapment, occur and because of the high electrical conductivity of moist compost or soil or grain etc. of typically a few mS / cm not occur in the seed itself.

The precompacted product is placed in an electrode system for a sufficient residence time to typically use about five to ten pulses per unit volume. Particularly suitable are pulse sequences with a pulse repetition rate of a few Hz up to about 20 Hz, since in these a particularly efficient energy input takes place. Because of the possible high conductivity of the material to be processed (usually bulk material), it is advantageous to use short high-power pulses with durations in the range of typically microseconds; with longer pulses and / or higher field strengths, the energy content of the applied power pulses and thus the total energy to be used increases without contributing to a significant improvement of the process. The optimal parameter set "Field strength - Pulse duration - Pulse count - Pulse repetition rate" depends on the required process (eg the type of seed to be sterilized) and can be found in the range described above.

The power impulse technology is to be measured as follows:

Voltage amplitude: U _p = D x E _opt , (1)

where E _{opt is} the optimum electric field strength for the respective seed type and the selected pulse duration and repetition frequency, and D is the layer thickness of the compacted material selected for the process. Both unipolar voltage pulses and bipolar pulses can be used.

Current amplitude: I _p = A x σ x U _p / D, (2)

with A: = electrode surface; σ: = electrical conductivity of the optionally compacted debris.

Alternatively, the above determination equations can be used when specifying parameters such as voltage or current amplitude for determining the other process parameters A, D.

The power electronics for the continuous generation of the high-power pulses is preferably based on a capacitor discharge with power semiconductors such as high-voltage thyristors, IGCTs or IGBTs o. A. executed and coupled directly into the material to be treated or via a high voltage pulse transformer.

In concrete embodiments in a production line different methods for applying compost, soil or other bulk materials are possible. Some particularly advantageous processes are: batch processes, e.g. B. pre-packaged in plastic bags

Products that are already pre-compacted, - Online processes, eg. B. integrated in Forderlinien of the

Finished product with a special Forderbandabschnitt with temporary mechanical compaction and optionally subsequent loosening in a Ruttelfeld, - combination of the latter method, eg. B. Batch process for a loose product with temporary compaction.

Furthermore, with the method described the targeted sterilization of certain, individual seed or pest insect species, which can occur as an impurity in the seed or grain production, possible, whereby an improved control z. B. can be done during production.

For this purpose, the process parameters must be specially tailored to the pest species to be sterilized, so that the desired products, eg. As grain seeds, cereals / corn for food production od. Like. , not negatively affected. If necessary, the procedure must be in a water bath

0. a. be executed to exclude impermissibly high levels of voids. Further application examples are pest control in natural products such. As hops, berry crops, coffee, cocoa, agricultural products in general, natural fibers in the raw or processed state, such. As wool, cotton, od. Like.

A continuous processing line with a Forderanlage 10, in which a device for sterilization is integrated, is shown in Figure 1. 1 means a higher-level system control and 100 the electrical equipment, which consists of two electrodes 102 and 103 and an electrical supply unit 101 with a high-voltage pulse generator. With the generator of the unit 101 high voltage pulses of predetermined height, voltage and distance can be generated. The unit 101 is powered by the plant controller

1, which also controls the Forderanlage 10 activated.

DETAILED DESCRIPTION FIG. 1 shows in detail a conveyor system 10 which contains a conveyor belt 15 running over drive rollers 11, 11 ', H'',H''', ... on which a bulk material 5 is transported. It is further a pinch roller 12 for compacting tion, for leveling and for Vergleichmaßigung the bulk material 5 available.

When passing the bulk material 5 through the pulsed electric field between the electrodes 102 and 103, the electrical voltage is applied, the electric field causes a sterilization. In pest insects, this "sterilizing" effect may also be that the electric field irreversibly damages the ability to move, so that insect insects remain localized and neither larger

Damage caused by food can still multiply further.

In another embodiment according to FIG. 2, a semi-continuous conveyor system consisting of a first conveyor device 20 and a second conveyor device 20 'is present, each consisting of drive rollers 21, 21' and a conveyor belt 25 or 25 '. On the first conveyor belt 25 there is a supply of plastic goods packed and precompacted goods 6, 6 ',... 6n, z. B. compost, to the station with the electric field influence. This station is formed with the supply unit 101 and the electrodes 102, 103 corresponding to the electrical equipment in FIG.

An advantage of the latter arrangement is that the intermediate or end product can already be delivered ready-made and is transported further after the electrical treatment. A repeated assembly is not necessary.

In the two examples described above according to FIGS. 1 and 2, the electrical supply unit 101 has a high-voltage pulse generator for unipolar pulses. However, bipolar pulses can also be generated and used for the intended purpose.

Claims

claims

Method of eliminating the germination and reproductive ability of animal and vegetable organic substances in bulk materials and / or their intermediate or end products, with the following measures:

- Pulsed electric fields are used,

- with the pulsed electric fields, the germ cells are denatured in existing seed and their germination eliminated, as well

- destroys the motility and reproductive capacity of biological contaminants, especially insect pests.

2. The method according to claim 1, characterized in that electric fields in the range of 0.5 kV / cm to over 10 kV / cm are used.

3. The method according to claim 2, characterized in that electric fields in the range of 1 kV / cm to 6 kV / cm are used.

4. The method according to claim 2 or 3, characterized in that pulse durations (pulse widths) from a few microseconds to tens of microseconds in the field low field strengths are used.

5. The method according to claim 2 or 3, characterized in that pulse durations (pulse half-widths) of tenth microseconds to microseconds seconds are used at field strengths in the range of several kV / cm.

6. The method according to any one of the preceding claims, characterized by a continuous supply of the to be treated bulk material.

7. The method according to any one of claims 1 to 5, characterized by an application in a batch process, in which the treated Good enough semicontinuous in individual lots is supplied to the electrode system.

8. The method according to claim 7, characterized in that the batch process for a loose product takes place with intermediate compaction of the material.

9. The method according to claim 7 or 8, characterized in that the batch process for finished prepacked products takes place.

10. The method according to one or more of the preceding claims, characterized by the use of pulse sequences with pulse repetition rates such that each volume element of the material to be sterilized with a plurality of pulses, preferably between 3 and 10 pulses, is applied.

11. Arrangement for carrying out the method according to claim 1 or one of claims 2 to 10, with a Fordereinrich- device for the continuous supply of bulk material or semicontinuous supply of material introduced in plastic films and an associated plant control, characterized in that in the field of Fordereinrichtung (10, 20, 20 ') an arrangement (100) of two electrodes (102, 103) is arranged, between which the bulk material (5) and / or the compacted material (6) passes, wherein the electrodes (102 , 103) by a unit (101) for supplying voltage via the unit for system control (1) with high voltage pulses are applied.

12. The arrangement according to claim 11, characterized in that the unit for supplying power to a pulse generator

(101) with power electronics based on a capacitor discharge with power semiconductors.