Method for treating domestic waste at low temperature

Abstract

The present invention relates to methods for managing domestic waste, and more particularly to methods for treating waste using a plasma chemical destruction method. The present invention aims to achieve a technical benefit that broadens the scope of technical solutions by providing a method for destroying domestic waste at low temperatures comparable to ambient temperature. This technical benefit is achieved by a destruction method in which domestic waste is fed into a reactor via an input port, and the ingress of atmospheric air into the reactor is restricted. The reactor is provided in the form of an enclosed chamber, the inner surface of which is fully or partially conductive and grounded. Electrodes protrude into the reactor and are isolated from the grounded surface. High-voltage pulses are applied to the electrodes. The pulses cause a corona discharge current to form in the gap between the electrodes and the conductive surface of the reactor.

Description

Technical Field

[0001] The present invention relates to a method for managing domestic waste, and in particular to a method for treating waste by a plasma chemical destruction method. Background Art

[0002] A known method for treating solid organic waste is implemented in the apparatus of patent RU2741004 (published on January 22, 2021), in which the solid organic waste is treated by vapor plasma gasification and conversion to produce synthesis gas. The treatment is carried out in a high-temperature plasma reactor, in which water vapor is used as the plasma support gas, and the temperature in the reaction zone is approximately 1600 to 2000°C.

[0003] The disadvantage of this method is that a large amount of heating must be carried out, and the treatment of solid organic domestic waste is not thorough because the synthesis gas produced after treatment also needs to be treated. In addition, the non-organic matter in the domestic waste cannot be treated with this method. Summary of the Invention

[0004] The object of the present invention is to achieve the technical effect of expanding the scope of technical solutions by providing a method for destroying domestic waste at a low processing temperature comparable to the ambient temperature.

[0005] This technical effect is achieved through a destruction method in which household waste is fed into a reactor via an input opening and the ingress of atmospheric air into the reactor is restricted. The reactor is provided as a closed chamber, the inner surface of which is fully or partially conductive and grounded. Electrodes protrude into the reactor and are isolated from the grounded surface. High-voltage pulses are applied to the electrodes. The pulses cause a corona discharge current to form in the gap between the electrodes and the conductive surface of the reactor.

[0006] According to the literature [1], a large number of carriers are formed near the electrode tip at each pulse. The carriers begin to multiply and diffuse toward the grounded conductive surface of the reactor chamber, gradually filling the gap between the electrodes and forming a corona discharge. The plasma of the corona discharge current exerts an influence on the water contained in the loaded waste, thereby causing the formation of free radicals due to the disintegration of water molecules H2O→OH·+H·. In addition, other active substances are formed in the reactor due to the corona discharge: О3, О2(a 1 Δ)、H2O2、ОН、O( 3P), NO, HNO2 and HNO3. The corona discharge also causes ultraviolet (UV) radiation. The above-mentioned active substances and UV radiation destroy any organic and inorganic substances contained in the domestic waste, thereby providing their complete destruction and forming harmless gaseous reaction products, namely water and carbon dioxide. The non-organic substances in the domestic waste are destroyed by the acid. The oxidation process of organic substances in water is a chain reaction [2]. Low-rate chain reactions can be initiated by atmospheric oxygen and ozone. High-rate chain reactions are initiated by OH· free radicals. In other words, the method provides plasma chemical destruction of organic and inorganic substances contained in the waste.

[0007] In one embodiment of the method, the conductive portion of the inner surface of the reactor chamber is pre-covered with a layer of aqueous liquid, which helps to form active particles in the reactor.

[0008] Preferably, the size of the gap between the electrode and at least one of the conductive portion of the inner surface of the reaction chamber or the surface of the aqueous liquid covering the portion is set in the range of 5 to 50 mm.

[0009] Preferably, household waste is fed into the reactor in a metered manner.

[0010] Preferably, the domestic waste dose is fed into the reactor in compressed form and entry of atmospheric air into the reactor is restricted.

[0011] Preferably, the pressure inside the reactor is reduced by 0.1 to 1.0 Pa compared to atmospheric pressure.

[0012] In one embodiment of the process, a vacuum is created at the output of the reactor to reduce the pressure within the reactor. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 A vertical cross section of a reactor for carrying out the claimed process is shown, wherein the following reference numerals are used:

[0014] 1. A reactor body having an inner cavity;

[0015] 2. Input port;

[0016] 3. Output port;

[0017] 4. The inner surface of the reactor cavity;

[0018] 5. The conductive part of the inner surface of the reactor cavity;

[0019] 6. Tip electrode;

[0020] 7. Isolation components;

[0021] 8. High voltage pulse source;

[0022] 9. Electrode end;

[0023] 10. Conductive bottom of the reactor;

[0024] 11. A device for quantitatively feeding waste to be treated;

[0025] 12. Electrostatic filter with extraction fan providing pressure reduction at reactor output. DETAILED DESCRIPTION

[0026] The method is implemented by using a reactor in the form of a closed body 1 with a grounded conductive bottom 10. An electrode 6 with a tip 9 protrudes into the body 1. The tip 9 is isolated from the conductive bottom 10 of the body 1 and points towards it. A portion of the compressed waste is fed from a device 11 for quantitatively feeding the waste to be treated via the input port 2 of the body 1 while limiting the entry of atmospheric air into the body 1. A high-voltage pulse is supplied from a source 8 to the electrode 6. As is known from the literature [1], each pulse generates a large number of charge carriers in the vicinity of the tip 9 of the electrode 6. The charge carriers begin to multiply and diffuse towards the conductive bottom 10 of the body 1, gradually filling the inter-electrode gap and forming a charge carrier corona discharge. The plasma of the corona discharge affects the water contained in the loaded waste and causes the formation of free radicals when destroying the water molecules: H2O→OH·+H·. In addition, other active substances are formed in the reactor due to the corona discharge: О3, О2(a 1 Δ)、H2O2、ОН、O( 3 P), NO, HNO2 and HNO3. Almost all the energy of the electrons in the plasma is used to form the specified active particles by dissociation, activation of the electronic state and creation of rotation and oscillation levels of the gas remaining in the reactor, thus forming a carrier corona discharge, so that no significant gas heating occurs. The above-mentioned active substances and UV radiation destroy any organic and inorganic substances contained in the waste to be treated, thereby completely destroying them and forming harmless gaseous reaction products, namely water and carbon dioxide. The non-organic matter of the waste is destroyed by the acid. The oxidation process of organic matter in water is a chain reaction [2]. Low-rate chain reactions can be initiated by atmospheric oxygen and ozone. High-rate chain reactions are initiated by OH· free radicals. In other words, plasma chemical destruction of organic and inorganic substances contained in the waste is provided in the device. The temperature of the body 1 and the gas leaving it via the output 3 is close to the ambient temperature. In fact, the entire energy of the electric pulse is consumed to form active particles, which significantly accelerates the natural reaction of the oxidation of domestic waste. The gaseous products of destruction enter the output 3 of the reactor.

[0027] Therefore, by providing a method for plasma chemical destruction of organic and non-organic substances in domestic waste at a temperature close to ambient temperature, a specific technical effect is achieved.

[0028] References

[0029] [1] Aristova NA, Piskarev IM, Ivanovskiy AV, Selemir VD, Spirov GM, Shlepkin SI Initiation of chemical reactions by electric discharge in a solid dielectric-gas-liquid system / / Journal of Physical Chemistry. 2004. Vol. 78. No. 7. pp. 1326–1331.

[0030] [2] Piskarev I.M. Oxidation-reduction processes in water initiated by electric discharge above the surface / / Journal of General Chemistry. 2001. Vol. 71. Issue 10. P. 1622. (Piskarev IM Oxidation-reduction processes in water initiated by discharge above the surface / / Journal of General Chemistry, 2001, Vol. 71, Issue 10, p. 1622.)

Claims

1. A method for treating domestic waste at low temperature, characterized in that: Domestic waste is fed into the reactor through an input port, and atmospheric air is restricted from entering the reactor. The reactor is in the form of a closed cavity, and its inner surface is fully or partially conductive and grounded. An electrode with a sharp tip extends into the reactor, and the electrode is isolated from the grounded surface. A high-voltage pulse is supplied to the electrode, and the pulse forms a corona discharge current in the gap between the electrode and the conductive surface of the reactor. The corona discharge current provides plasma chemical destruction of organic and inorganic substances contained in the domestic waste.

2. The method for low-temperature treatment of domestic waste according to claim 1, characterized in that: The conductive portion of the inner surface of the cavity of the reactor is pre-covered with a layer of aqueous liquid.

3. The method for low-temperature treatment of domestic waste according to claim 1, characterized in that: The size of the gap between the electrode and the at least one conductive portion of the inner surface of the cavity is in the range of 5 to 50 mm.

4. The method for low-temperature treatment of domestic waste according to claim 2, characterized in that: The size of the gap between the electrode and the surface of the aqueous liquid covering the conductive portion of the inner surface of the cavity is in the range of 5 to 50 mm.

5. The method for low-temperature treatment of domestic waste according to any one of claims 1 to 4, characterized in that: The domestic waste is fed into the reactor in a quantitative manner.

6. The method for low-temperature treatment of domestic waste according to claim 5, characterized in that: The domestic waste is fed into the reactor in compressed form, and entry of atmospheric air into the reactor is restricted.

7. The method for low-temperature treatment of domestic waste according to claim 1, characterized in that: The pressure in the reactor is 0.1-1.0 Pa lower than the atmospheric pressure.

8. The method for low-temperature treatment of domestic waste according to claim 7, characterized in that: A vacuum was created at the output of the reactor.

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