OA21905A - Method for low-temperature transformation of domestic waste. - Google Patents

Abstract

The invention relates to methods of household waste management, in particular, to methods of disposing waste by plasma-chemical destruction method. The invention is directed to attaining a technical effect of broadening range of technical solutions by providing a method of destruction of household waste at low temperature of treatment that is comparable to environment temperature. This technical effect is attained by a destruction method, where household waste is fed into a reactor via an input opening, and entry of atmospheric air into the reactor is restricted. The reactor is provided in form of a closed cavity, which inner surface is made conductive entirely or partially and grounded. An electrode protrudes into the reactor, andthis electrode is isolated from the grounded surface. High-voltage pulses are supplied to the electrode. The pulses cause formation of corona discharge streamers in a gap between the electrode and the conductive surface of the reactor.

Description

METHOD OF LOW-TEMPERATURE TREATMENT OF HOUSEHOLD WASTE

Field of invention

The invention relates to methods of household waste management, in particular, to methods of disposing waste by plasma-chemical destruction method.

Prier art

There is a known method of solid organic waste treatment implemented in a device of patent RU2741004 (published on January 22, 2021), where solid organic waste is treated by 10 vapor plasma gasification conversion with génération of syngas. The treatment is performed by a high-temperature plasma reactor, where water vapor is used as a plasma-supporting gas and température of reaction area is about 1600 to 2000 °C.

Disadvantages of this method are necessity of substantial heating for its carrying out and incomplète treatment of solid organic household waste, since the treatment results in syngas that 15 also needs to be disposed. Moreover, non-organic substances contained in household waste cannot be treated this way.

Summary of invention

The invention is directed to attaining a technical effect of broadening range of technical solutions by providing a method of destruction of household waste at low température of f 20 treatment that is comparable to environment température.

This technical effect is attained by a destruction method, where household waste is fed into a reactor via an input opening, and entry of atmospheric air into the reactor is restricted. The reactor is provided in form of a closed cavity, which inner surface is made conductive entirely or partially and grounded. An electrode protrudes into the reactor, and this electrode is îsolated 25 from the grounded surface. High-voltage puises are supplied to the electrode. The puises cause formation of corona discharge streamers in a gap between the electrode and the conductive surface of the reactor.

According to document [1], a large number of streamers are formed near the electrode tip at each puise. The streamers start multiplying and spreading towards the grounded conductive 30 surface of the reactor cavity, gradually populating the inter-electrode gap and forming corona discharge. Plasma of corona discharge streamers exerts an effect on water contained in the loaded waste, thus causing formation of free radicals due to disintegration of water molécules H₂O —» OH· + H·. In addition, other active substances are formed in the reactor due to corona discharge: O₃, O₂(a^!A), H2O2, OH, O(³P), NO, HNO2 and HNO₃. Corona discharge also causes 35 ultraviolet (UV) radiation. The above-mentioned active substances and UV radiation destroy any ² 21905 organic and inorganic substances contained in the household waste, thus providing complété destruction thereof and formation of harmless gaseous reaction products, namely, water and carbon dioxîde. Non-organic contents of the household waste are destroyed by acids. Process of oxidation of organic substances in water is a chain reaction [2]. Low-rate chain reaction may be initiated by atmospheric oxygen and ozone. High-rate chain reaction is initiated by OH* radicals.

In other words, plasma-chemical destruction of both organic and inorganic substances contained in the waste is provided by this method.

In one embodiment of the method, the conductive portion of the reactor cavity inner surface is covered by a layer of a water-containing liquid in advance, which facilitâtes formation 10 of active particles inside the reactor.

Preferably, size of the gap between the electrode and at least one of conductive portions of the reactor cavity inner surface or surface of the water-containing liquid covering this portion is provided in range of 5 to 50 millimeters.

Preferably, the household waste is fed into the reactor in dosed amounts.

Preferably, the household waste doses are fed into the reactor in compressed form and entry of atmospheric air into the reactor is restricted.

Preferably, pressure inside the reactor is decreased by 0.1 to 1.0 Pa compared to atmospheric pressure.

In one embodiment of the method, dépréssion is provided at the reactor output to 20 decrease pressure inside the reactor.

Brief description of drawings

Fig. 1 shows a vertical cross-section of the reactor implementing the claimed method, where the following designators are used: ¹ reactor body with inner cavity;

2 input opening;

output opening;

inner surface of reactor cavity;

conductive portions of inner surface of reactor cavity;

tipped electrode;

7 isolating members;

source ofhigh-voltage puises;

electrode tip;

conductive bottom of reactor;

device for dosed feeding waste to be treated;

12 electrostatic filter with extraction air fan providing dépréssion at reactor output.

Detailed description of embodiments

The method is implemented by use of the reactor provided in form of the closed body (!) with the conductive bottom ( 10) that is grounded. The electrode (6) having the tip (9) protrudes into the body (l). The tip (9) is isolated from the conductive bottom (10) of the body (1) and 5 directed towards it. A portion of compressed waste is fed from the device (11) for dosed feeding waste to be treated via the input opening (2) of the body (1), while entry of atmospheric air into the body (1) is restricted. High-voltage puises are supplied to the electrode (6) from the source (8). As it is known from document [1], large number of streamers occur near the tip (9) of the electrode (6) with each puise. The streamers start multiplying and spreading towards the 10 conductive bottom (10) of the body (1 ), gradually populating the inter-electrode gap and forming streamer corona discharge. Plasma of corona discharge exerts an effect on water contained in the loaded waste and causes formation of free radicals upon destruction of water molécules: H2O OH· + H·. In addition, other active substances are formed in the reactor due to corona discharge: O3, Oiia'A), H₂O₂, OH, O(^jP), NO, HNO₂ and HN0₃.Corona discharge also causes ultraviolet (UV) radiation. Almost entire energy of électrons in plasma is spent for formation of the indicated active particles by dissociation, activation of électron States and création of rotation and oscillation levels of gas resided in the reactor, where streamer corona discharge is formed, so no substantial gas heating occurs. The above-mentioned active substances and UV radiation destroy any organic and inorganic substances contained in the waste to be treated, thus providing 20 complété destruction thereof and formation of harmless gaseous reaction products, namely, water and carbon dioxide. Non-organic contents of the waste are destroyed by acids. Process of oxidation of organic substances in water is a chain reaction [2]. Low-rate chain reaction may be initiated by atmospheric oxygen and ozone. High-rate chain reaction is initiated by OH· radicals. In other words, plasma-chemical destruction of both organic and inorganic substances contained 25 in the waste is provided in the device. Température of the body (1) and gases leaving it via the output opening (3) is near the environment température. In fact, entire energy of electric puises is spent for formation of the active particles, which substantially accelerate natural reactions of oxidation of household waste. Gaseous products of destruction enter the output opening (3) of the reactor.

Thus, the specified technical effect is attained in form of providing the method of plasmachemical destruction of both organic and non-organic substances contained in household waste at a température near the environment température.

। , [1] ApncTOBa H.A., HncKapeB H.M., Ηββηοβοκηϊϊ A.B., CeneMirp B.H., Cnnpoa Γ.Μ.,

LUjienKHH C.H. HHMUHHpoBaHnexnMH*iecKnxpeaKUHÜnoAaeiicTBneM3JieKTpHHecKoropa3paaa b 35 cHCTeMeTBep^BiHZtn3JÎeKTpHK-ra3->KWAK0CTb H XypHajrcjinaHBecKOWXiiMmi. 2004. T. 78. Ne 7. C.

⁴ 21905

1326-1331. (Aristova N. A., Piskarev I.M., Ivanovskiy A.V., Selemir V.D., Spirov G.M., Shlepkin S.L Initiation of Chemical reactions by electrical discharge in dielectric-gas-liquid configuration /7 Physical Chemistry Journal, 2004, Vol. 78, #7, pages 1326-1331.)

[2] nucKapeB 14.M. OKMCJiHTejtbHO-BoccTaHOBUTejtbHbienpoueccbi b BOJie,

MHMunHpoBaHHbieaneKTpMuecKKMpaipsLïioMHaiieenoBepxHocTbio // >KypHajio6iiieHxnMHH. 2001. i

T. 71. Bun. 10. C. 1622. (Piskarev I.M. Oxidation-reduction processes in water initiàted by electrical discharge above water surface // General Chemistry Journal, 2001, Vol. 71, Issue 10, page 1622.)

Claims (8)

1. l. A method of low-temperature treatment of Household waste, characterized by thaï Household waste is fed into a reactor via an input opening, and entry of atmospheric air into the reactor is restricted, the reactor is provided in form of a closed cavity, which inner surface is made conductive entirely or partially and grounded, an electrode protrudes into the reactor and this electrode is isolated from the grounded surface, high-voltage puises are supplied to the electrode and the puises cause formation of corona discharge streamers in a gap between the electrode and the conductive surface of the reactor.
2. 2. The method of low-temperature treatment of Household waste of claim 1, wherein the conductive portion of the reactor cavity inner surface is covered by a layer of a water-containing liquid in advance.
3. 3. The method of low-temperature treatment of Household waste of claim 1, wherein size of the gap between the electrode and at least one of conductive portions of the cavity inner surface is in range of 5 to 50 millimeters.
4. 4. The method of low-temperature treatment of Household waste of claim 2, wherein size of the gap between the electrode and surface of the water-containing liquid covering the conductive portion of the cavity inner surface is in range of 5 to 50 millimeters.
5. 5. The method of low-temperature treatment of Household waste of any one of claims 1-

   4, wherein the Household waste is fed into the reactor in dosed amounts.
6. 6. The method of low-temperature treatment of household waste of claim 5, wherein the household waste doses are fed into the reactor in compressed form and entry of atmospheric air into the reactor is restricted.
7. 7. The method of low-temperature treatment of household waste of c any one of claims 1-6, wherein pressure inside the reactor is decreased by 0.1 to 1.0 Pa compared to atmospheric pressure.
8. 8. The method of low-temperature treatment of household waste of claim 7, wherein dépréssion is provided at the reactor output.