Method of plasma-catalytic processing of solid domestic wastes. RU patent 2504443.

FIELD: process engineering.

SUBSTANCE: invention relates to processing of solid domestic wastes. Proposed process comprises plasma chemical pyrolysis of homogenised mix. Said mix represents a three-phase system homogeneously dispersed in raw stock. Said system consists of highly-dispersed catalyst particles of methane-hydrogen fraction extracted at pyrolysis product separation and pyrolysis fluid products. Besides, this process comprises quenching of pyrolysis products extraction of commercial carbon and solid particles of used catalyst by filtration and pyrolysis products separation to obtain methane-oxygen fraction and pyrolysis liquid products. Finally, this process recycles a portion of methane-hydrogen fraction to plasma chemical pyrolysis.

EFFECT: simplified process adapted to solid wastes processing.

4 cl, 1 ex

The present invention is applicable to environmental protection, namely, in the field of waste processing.

Currently, the world has developed critical situation with recycling of the solid household waste. In the existing practice of such waste is proposed process on installations of thermal neutralization, where as a result of pyrolysis get dry ash - raw materials for production of building materials and asphalt concrete mixtures. This solution is not satisfactory, because solid residues pyrolysis contain heavy metals and, therefore, not suitable for industrial use and require disposal. In addition, organochlorine compounds contained in waste, lead to contamination of the environment by dioxins, furans, is precipitated and PCBs are extremely hazardous to human health and the environment in General.

The most promising at present is the technology of processing of solid domestic waste with the use of plasma technology of processing, using low-temperature plasma (2000-10000 degrees C).

Plasma-chemical methods provide a higher degree of processing (conversion of the raw material is 96-98% of the mass), increase the depth of processing of molecular chemical compounds and reduce the number of stages and reduce the extent of chemical processes.

The processes of plasma-chemical processing of organic raw materials can be classified according to the following criteria:

1) plasma gas («working body» plasmatron):

a) gas, including air;

b) water vapor;

a) gaseous hydrocarbons;

d) hydrogen or gases;

d) inert gases;

e) other gases, including the mixture of the gases mentioned above;

2) the presence or absence of a catalyst:

a) no catalyst;

B. using a catalyst.

In accordance with this classification, below is a description of the main ways of plasma processing of organic raw materials.

Plasma-chemical processing of heavy oil residues

In method [in Russian Federation Patent 2131906, IPC C10G 15/12, 27.01.1997] processing of heavy resin emulsion containing water and coke, employ the technique of plasma pyrolysis and afterwards quenching products and their division. Raw materials pre-homogenized, pyrolysis products after tempering clear of acetylene by catalytic hydrogenation, condensed and sent to the main production condensate return on hydrogenation of acetylene, the excess is mixed with raw materials and faction after splitting is used as a plasma-forming gas and/or fuel oil. Method allows to organize the transition to low-waste closed system of complex processing of raw materials due to dispose of environmentally hazardous waste, petrochemical and chemical industries, as well as to increase the degree of utilization of raw materials and output of the end product.

In method [in Russian Federation Patent 2129584, IPC C10G 15/12, 19.07.1996] heavy oil residues subjected pyrolysis in a stream of hydrogen containing gas with the receipt of pyrogas, technical carbon and translation of the sulfurous compounds to hydrogen. Products of pyrolysis clear of technical carbon in the subsequent sedimentation of rare metals known methods, hydrogen sulfide subjected dissociation in microwave plasma obtaining polymeric sulfur and hydrogen, returning the last stage of pyrolysis. Of the cleaned gases synthesize motor fuel. Allows to expand the raw materials base, improve the efficiency of the recycling process and increase the degree of utilization of raw materials.

There is a method of hydrocracking heavy hydrocarbon fractions [RF Patent 2319730, IPC C10G 15/12, 09.11.2006]. Pre-heated to 60-370°C heavy hydrocarbon fraction subjected to «bombardment» hydrogen ions and hydroxyl ions group in the reactor without oxygen, hydrogen ions and hydroxyl ions group serves in the chamber in the form of plasma. The method is implemented in the device for the hydrocracking heavy hydrocarbon fractions, which contains the reactor having a level sensor, temperature sensor, outlet not reacted part of hydrocarbon fractions in a vaporous condition. In the upper part of the reactor is installed plasma torch nozzle, but in the bottom of the tube feeding heavy hydrocarbon fractions from the nozzle, installed with the possibility of regulating the distance from the nozzle torch up to its upper part. Method and device for its realization are aimed at simplifying technology hydrocracking heavy hydrocarbon raw material, increase of productivity due to the possibility of regulating the degree of fragmentation of hydrocarbon molecules time «bombing» of their ions, the kinetic energy of ions, initial temperature of hydrocarbon molecules, and also the possibility to operate the device in two operating modes: the gas or liquid of light fractions.

Hydrocracking using plasma technologies described in method [in Russian Federation Patent 2343181, IPC C10G 15/12, 17.10.2007]. Pre-heated to 60-350°C heavy hydrocarbon fraction subjected to plasma for splitting in the zone of high temperature hydrocarbon molecules into atoms without oxygen, followed by «bombing» of other hydrocarbon chains, crushing them and in the zone of reactions leading to the formation of light hydrocarbon fractions. Plasma is an ionized high-temperature gas.

In [Kashapov NF, Nefedov Y.S., B.A., Fakhrutdinov IM Decomposition of heavy hydrocarbons electric arc plasma. 36th international (Zvenigorod) conference on plasma physics and fusion, 2009, p.1] we are talking about recycling of high-viscosity oil residues - black oil and tar. It is emphasized that in recent years as one of the options deeper processing of heavy oil and mazut offered use of a powerful destructive process of pyrolysis in the plasma jet of inert gas, the hydrogen-bearing gas, nitrogen, has unique opportunities as the selectivity of chemical reactions, and ease of implementation of the technological process. The intensity of chemical reactions depend on many factors, the main of which are the temperature of the gas and raw materials, molar ratio between the heating medium and raw materials, state molecules, speed of reactions, processes of gas dynamics, heat and mass transfer, electrodynamics and other Kinetic description of plasma-chemical technological processes allows to trace their evolution in time with respect to temperature, pressure, feedstocks. Research conducted in the plasma generator with longitudinal blowing arc and with vortex arc stabilization. Heated to 80 C oil was supplied in the area of an outlet of plasma from the anode. Heating of gas in electric arc was driven mainly by the energy released in a pillar of arc. Mingling with plasma forming gas that reacts weight passed through the reaction chamber and entering the camera hardening. After the camera hardening processed product hit the camera with the large volume, where's lined on the distribution of the composition and flowrate and passed through the area of final cooling. At the output of a gaseous product processing had a temperature of 25-30°C. the Final product had in the composition of the gas and solid phases. The solid phase was a fine soot. Production of light fractions of hydrocarbons due to thermal splitting of heavy fractions possible at temperatures below 1000 K. Therefore, in electric arc plasma with a temperature of 3000-6000 To mainly hydrocarbons are formed from carbon bond type C 2 H 2 , C 2 H 4 C 4 H 4 , as well as molecular hydrogen and atomic carbon.

Plasma-chemical processing of solid or a mixture of solid and liquid raw materials

A method of obtaining the pyrolysis of acetylene crushed solid materials, pre-mixed with water vapor in the pulsating within 0,001-0,009 with the jet plasma [RF Patent 2009112, IPC C10G 15/12, 06/05/1992]. Used as raw material organic waste.

There is a method of processing and disposal of bottom sediments of oil-slime barns [RF Patent 2201407, IPC C10G 15/12, 30.10.2001]. The method includes plasmochemical processing of bottom sediments in the presence of hydrogen, preheated to a temperature of 3000-4000'c with obtaining of unsaturated hydrocarbons C 2 C 4 . Before plasma-chemical processing of sediments from oil-storage pits diluted with crude oil mass ratio of 1:0.25 and heated to a temperature 90-95°C. Technical result is the creation of a compact, high-performance, bezynertsionnoj, environmentally friendly waste processing technology of bottom sediments of oil-slime barns with obtaining the target products.

The way of gasification of solid carbonaceous materials [in Russian Federation Patent 2213766, IPC C10G 15/12, 17/06/2002] provides for acquisition of synthesis-gas from waste plastic and includes the submission of dispersed raw materials, plasma of water vapor, the confusion, the subsequent gasification of raw materials and discharge of the resulting products. The method of two-phase flow of dispersed raw materials and water plasma is sent for a bath melt, formed by melting not reacted part of dispersed raw materials. Received products of gasification is withdrawn in counter to the original supersonic jet and mix with subsequent formation of swirling flow. The method is implemented in the device containing the reactor, superior plasmatron nodes adjustable input of dispersed raw materials and water vapor, nodes output synthesis gas and solid particles. the reactor consists of associated gas duct plasma and cyclone reactors. The method allows to increase economic efficiency process of synthesis gas production is of high quality in a compact reactor for one technological stage.

Plasma-catalytic processing of hydrocarbon raw materials

Known method of disposal of oil slimes [RF Patent 2218378, IPC C10G 15/12, 09.12.2002] by plasma processing of oil sludge in the presence of catalysts. Plasma processing of oil sludge is carried out in the form of dispersed water-and-fuel combustible compositions in the conditions of catalytically active air plasma of electric discharges in the mass-average temperature 1500-6000 To 10 -5 -10 -3 C when the content of ultradispersed of catalytically active materials 0,01-1,0%mass, received in the process of oil sludge reactor contains the plasma generator, reaction chamber, nozzle holes input of raw materials and the products, and the plasma generator, reaction chamber and nozzle disk placed horizontally on one of the axial line, plasma generator and disk nozzle attached to the reaction chamber from opposite sides, nozzle disk contains the drive shaft, running external camera with disks-emulsifiers and chamber containing the Bush with holes and drive-disperser, interconnected body situated in it sealing ring and the reaction chamber contains a quartz tube and water-cooled enclosure with on him pipe the output of recycling products. The advantages of the installation and of the method include: small size, compactness and mobility of the installation, high specific capacity of the installation, low specific power consumption for recycling, receive more energy from the recycling of industrial and domestic needs, low content of pollutants in the treated waste gases installation, lack of polluting organic substances in solid products recycling, no discharge of contaminated water.

Obtaining ethylene in the way [in Russian Federation Patent 2315802, IPC C10G 15/12, 28.01.2004] provides for the conversion of methane plasma-catalytic oxidation. The method includes catalyst activation microwave radiation and formation of a nonequilibrium «cold» microwave plasma. Simultaneously catalyst activation microwave radiation and microwave plasma and create a nonequilibrium plasma «cold» microwave plasma.

The combination of plasma, and catalytic pyrolysis processes implemented in the way of acetylene from natural gas [Khudyakov G.N. and other The impact of adjuvants on the plasmochemical process of formation of acetylene from natural gas. / II all-Union Symposium on plasma chemistry. - Theses of reports. - Riga: , 1975. - .243-246]. In this way serves from the feeder into the plasma stream of hydrogen with additive (potassium carbonate powder, mix RSS with jets of natural gas and carry out the reaction of pyrolysis and then cooled products of the reaction. This method allows to increase the output of the end product, but does not enable full use of adjuvants, because after the introduction of the additive mixture of plasma flow with natural gas is not sufficiently homogeneous. Thus intensity of plasmochemical processes of pyrolysis, the increase of the unit cost of electricity and increased consumption of additives.

A method of refining oil and oil residues [RF Patent 2149885, IPC C10G 15/12, 22.04.1997]. This method, carry out the plasma chemical pyrolysis oil residues in the presence of a catalyst, hardening of the pyrolysis products of division of products of pyrolysis. Use fine catalyst regardless of the phase state (solid, liquid or gaseous) pre-homogeneously dispersed raw materials, and then the resulting mixture is subjected to pyrolysis. The catalyst is, preferably, 1-5% of the mass of raw material. Used catalyst after the division of the products of pyrolysis regenerate and return to the stage of pyrolysis. The process consists of the stage of raw materials preparation of the catalyst, where the raw material is mixed with finely dispersed catalyst, homogenize the mixture and sent to the next stage, where mixture is subjected to pyrolysis with reception of products of pyrolysis, which refer to the stage of separation. At the division of the products of pyrolysis catalyst regenerate and return to the stage of raw materials preparation, technical carbon is collected for further use. share on unsaturated hydrocarbons C 2 C 4 , petrol and faction, returning the last stage of the plasma pyrolysis.

The disadvantage of this method is the complexity of the technological process, the contour of the necessity of requiring a catalyst and reuse it in the process.

The objective of this invention is to simplify the process of technology in the use of a catalyst, the intensification of the process through the use of more active catalyst, as well as the adaptation process to use for processing of solid domestic waste.

In accordance with the present invention of this goal is achieved by way of solid household wastes, including plasmochemical pyrolysis homogenized mixture, which is a homogeneous in raw three-phase system consisting of fine particles of catalyst, separated during the separation stage of the pyrolysis products and liquid products of pyrolysis, hardening of the pyrolysis products, allocation of technical carbon and particulate exhaust catalyst filtering, and stage separation of the products of pyrolysis with obtaining faction, liquid products of pyrolysis and recycle parts faction on the stage of plasma pyrolysis.

Preferably as a catalyst for use superfine particles concentrate metal compounds, obtained in plasma-chemical pyrolysis of solid waste in a mixed plasma.

Preferably use superfine particles of catalyst processed in an environment of low temperature plasma, formed in the interelectrode space at a voltage between the electrodes 1.5 to 5.5 kW and frequency of 0.25-0.8 MHz, in the presence of bubbles mixture with a size of 0.1-0.5 mm and in the presence of the solid parts of the original catalyst with size 10 to 100 microns.

The process is carried out as follows. To capacity submit solid domestic waste. There also serves three-phase system, representing a high dispersion catalyst, faction, highlighted during the separation stage of the pyrolysis products or other hydrogen-containing gas and liquid products of pyrolysis.

Three-phase system is obtained in plasma disperser, which represents a closed volume, which are horizontal electrodes, which is supplied by the electric current with a voltage of 1.5 to 5.5 kW and frequency of 0.25-0.8 MHz. There (in plasma disperser) serves a large metal particles (0.1-0.5 mm), mixture in the form of bubbles size 10 to 100 microns. Education finely dispersed particles of catalyst occurs as a result of the electrical discharge between horizontal electrodes and large particles of metal. Mixing in a plasma disperser occurs due to the circulation of a three-phase flow in the circuit plasma dispersant.

Of the capacity of raw materials together with the three-phase system is sent to the homogenizer ( mixing device) with additional mixing with the help of the circulation pump in the circuit «capacity-homogenizer-capacity».

Of homogenizer with the help dozatora homogenized mixture flows in the plasma reactor, having at least one torch, a gas which is mixture obtained in the course of the process of plasma pyrolysis.

The solid products of pyrolysis of a plasma reactor sent for disposal or recycling for further use as a catalyst or as a component of building materials.

Gaseous pyrolysis products of a plasma reactor is sent to the quenching unit, where there is a sharp decrease in temperature and the termination of the majority of reactions, basically, the radical-chain. Of hardening device pyrolysis products is sent to the filter (e.g. bag filter), where separate technical carbon and other solid particles, including particles spent catalyst. In case, when the process of plasma pyrolysis combined with the recycling of solid waste, selected on the stage filtration of solid products sent in a plasma reactor, them to solid waste.

After stage filtration receive , who share with liquid pyrolysis products, which are partly directed to the plasma disperser to obtain a three-phase system, and faction, part of which is sent to the plasma disperser to obtain a three-phase system. The resulting three-phase system is mixed with municipal solid waste, received a mixture after homogenization subjected pyrolysis.

The advantage of the proposed method is to use a more active finely catalyst and a significant simplification of the process of technology, precluding the extraction of a catalyst and reuse it in the process. The high activity of the catalyst is associated with getting it in a current of low-temperature plasma (electrical discharge between the electrodes), which will result in the activation of the catalyst.

Example of the method of plasma-catalytic processing of solid domestic waste

The three step system received in the plasma disperser, which represents a closed volume, which are horizontal electrodes, which is supplied by the electric current with a voltage of 5.5 kV and frequency of 0.6 MHz. In plasma disperser served large - 0.1-0.5 mm particle concentrate metal compounds, obtained in plasma-chemical pyrolysis of solid waste in a mixed plasma, faction in the form of bubbles the size of 10-100 microns and liquid products of pyrolysis. Average consumption of a concentrate of compounds of metals amounted to 4.2 kg/h, faction - 11.3 kg/h of liquid products of pyrolysis - 31.5 kg/h; Mixing in a plasma disperser provided by circulation of a three-phase flow in the circuit plasma dispersant. Concentrate metal compounds, obtained in plasma-chemical pyrolysis of solid waste in a mixed plasma, according to the data of x-ray fluorescence analysis contained iron, Nickel, cobalt, tungsten, chromium, manganese, as well as oxides and carbides of these metals, the content of iron compounds in concentrate exceed the content of compounds of other metals.

Of the capacity of the solid domestic waste, together with the three-phase system is sent to a homogenizer. mixture served in a plasma reactor. In the reactor the mixture for 10 -3 treated with plasma obtained from the use of the plasma torch EDP-200 (Kurchatov Institute) with capacity of 200 kW.

Gaseous pyrolysis products of a plasma reactor cooled in hardening device, the device hardening pyrolysis products placed in the bag filter, where the separated carbon black and other solid particles, including particles spent catalyst. After pyrolysis allocated, on average, 37 kg/solid products of pyrolysis.

After stage filtration sent to the stage of separation, where it was isolated liquid products of pyrolysis and faction. After pyrolysis allocated, on average, 71 kg/h of liquid products of pyrolysis, 92 kg/h faction, then 12% received faction sent in plasma disperser to obtain a three-phase system, the plasma disperser to obtain a three-phase system also sent 44% of pyrolysis liquid products.

1. Method for processing of solid household waste, including plasmochemical pyrolysis homogenized mixture, representing a homogeneous in raw three-phase system consisting of fine particles of catalyst, separated during the separation stage of the pyrolysis products and liquid products of pyrolysis, hardening of the pyrolysis products, allocation of technical carbon and particulate exhaust catalyst stage of filtration and separation products of pyrolysis with obtaining faction and liquid products of pyrolysis and recycle parts faction on the stage of plasma pyrolysis.

2. The method according to claim 1, characterized in that in the capacity of catalyst use superfine particles concentrate metal compounds, obtained in plasma-chemical pyrolysis of solid waste in a mixed plasma.

3. The method according to claim 1, characterized in that the use superfine particles of catalyst processed in an environment of low temperature plasma, formed in the interelectrode space at a voltage between the electrodes 1.5 to 5.5 kW and frequency of 0.25-0.8 MHz, in the presence of bubbles mixture with a size of 0.1-0.5 mm and in the presence of the solid parts of the original catalyst, with the size of 10-100 microns.