Method of cleaning exhaust gases and installation for its implementation (options)
(57) Abstract:Usage: in the pulp and paper, oil refining and chemical industries, as well as energy for purification of exhaust gases. The inventive flow of exhaust gases influence of nonequilibrium low-temperature plasma and/or irradiation of the polymer, incorporate in its structure harmful components or their derivatives. Plasma and/or irradiation (e.g. UV) carry out the activation reaction of the purified gas and polymer over the whole cross section of the reactor. The polymer is blown into the reactor in a powdered state, and the plasma is fed into the reactor at a supersonic speed of the plasma generators. The reactor is connected to the piping of the exhaust gases to which the desiccant can be connected to the plasma generators. The output of the reaction products is performed either with the separator of solid-phase components of the reaction products, having a compilation of recent or placed in the reactor plates made of polymer, or coated. The reactor has an input device of the polymer. 3 N. and 15 C.p. f-crystals, 5 Il. The invention relate to exhaust gas cleaning industrial and power plants against the harmful gas components: oxides of the local structures in the petroleum, pulp and paper and chemical industries and power generation.Currently, there are various ways o harmful gas components included in the exhaust (flue) gases industrial and power plants, mainly nitrogen oxides, sulfur.Found the application of known methods for cleaning exhaust gases are divided into two types.The first includes the chemical, absorption, catalytic.To the second - physicochemical using electron beams, microwave discharges, plasma jets, corona, etc.The most common chemical methods are methods using the introduction of various active substances in the purified gases, with the aim of creating recovery processes, oxidation, catalysis, etc., that contribute to the conclusion of harmful substances from exhaust (flue) gases.Known industrial plasma cleaning method using NH3and microwave discharge .Specified known purification method includes the introduction of NH3in the flow of the purified gas with simultaneous creation of a microwave discharge in the mixture. When this happens the formation of radicals, which shall enter the in the presence of free oxygen and water vapor forms nitrates and ammonium sulphate in the solid state.The disadvantage of this known method is the high cost, multi-stage and toxicity of the introduced component NH3and the impossibility of purification from various sulfur compounds (except oxides of sulfur).Known device for purification of exhaust gases from SO2the exposure to plasma containing a reactor connected to the piping of the exhaust gases and provided with a section of the gas plasma and the output of the reaction products .This setting limits the cleaning process of the dissolution of oxides and does not provide the necessary degree of purification of exhaust gases from sulfur compounds and oxides before the exhaust gases in the environment. In addition, the known device requires high energy costs per unit of gas to be purified and has a restriction on the flow of the purified gas.The closest analogue of the invention is a method of cleaning exhaust gases from impurities and device for its implementation .The method is carried out by passing through the reactor off-gases, which enter the stream of hydrocarbon low-temperature nonequilibrium plasma with subsequent separation of the solid phase products repasy.However, this solution has significant drawbacks: the use of hydrocarbon plasma makes the process technically hazardous, especially when large volumes of gas to be purified, the purification process is carried out only for a limited part of the purified gas, for cleaning requires large volumes of hydrocarbons to the instructions of the plasma, which is environmentally disadvantageous (low efficiency) and technically difficult to implement.The purpose of the claimed invention is to develop a method and creating a safe plant, providing clean exhaust gases from various harmful components (SO2, NO2CS2CH3SH, COx, is actually present in industrial gas emissions, without disturbing the underlying process at low working voltage of the plasma generation and high flow rate of the purified gas, and increasing efficiency of plants at high concentrations of harmful components.The claimed technical result according to the method of purification is achieved by the fact that the reactor is additionally injected polymer or polymerizable monomer, incorporate in its structure harmful components or their derivatives, and carry out isdi suitable for irradiation zone of interaction of the plasma with the purified gas and the polymer or polymerizable monomer) to use ultraviolet radiation. Nonequilibrium low-temperature plasma can be created from previously drained waste (cleaned) gas, nitrogen, natural gas or mixtures thereof, including, with the inert gas.In the resulting plasma are electronovision neutral or charged particles (atoms, molecules, radicals, ions and other) (see Fig.1) with internal excitation energies and ionization (from several to tens of eV) is higher than the energy of bond harmful components (SO2, NO2CH3SN, H2S) of the purified gas.The effect of the components of the jet plasma harmful components caused by the resonance conditions of the reaction excitation (or disconnection) of particles, such as molecules SO2with the formation of SO*2(in the singlet or triplet States) and SO.Triplet SO2may react with olefinic polymer structures, initiating radical processes and embedding SO2. For example:
.Especially intensively act unsaturated polymers on the basis of hydrocarbons with a high concentration of paramagnetic centers, building radicals SO, SH, S2and other (see Fig.4), and ultraviolet radiation increases the MSE of the different types of reactions, in infrared absorption spectra recorded radicals NH, NH2and NO2included in the polymer structure of the injected polymer embedding of NO2in the polymer, formed on the basis of hydrocarbons occurs in the reaction:
.A positive role in the polymerization process plays a mercaptan due to the recoil of a hydrogen atom in the interaction with the growing polymer radical, molecule becomes the initiator of a polymer chain.Thus, the mechanism of polymerization is determined not only by high concentrations of excited particles in the jet plasma, but also the structure of the injected polymer mainly by the presence of free radicals and paramagnetic centers.There are two installation options, implementing the above method.The claimed technical result according to the first embodiment of the installation for purification of exhaust gases is achieved by the fact that it further comprises an input device in the reactor, the polymer in powder form, incorporate in its structure hazardous components: SO2, NO2, CO, SH, etc.According to the second variant, the device of reaction products can be RA is its structure of these harmful components and their derivatives, or having a coating of the specified polymer in the form of a spray, powder or film.In both cases, the installation of low-voltage plasma generator connected to the piping of the exhaust gases and can be made in the form of electric arc plasma torch DC low operating voltage U and possible adjustment by changing the spacing between the electrodes. While EbU2Eiwhere Ebthe excitation energy, Ei- maximum ionization potential component of a plasma-forming gas. We can also perform part of the reactor in the form of cascading plasma torch that creates a plasma from the dried exhaust gas floatation device injection of polymer in the reactor after the release of plasma from the cascading plasma torch.Installation in both cases may contain a source of ultraviolet radiation for irradiation zone of interaction of gas, plasma and polymer for the intensification of the processes of initiation, polymerization and copolymerization.The invention is illustrated in the following material.In Fig.1 shows the emission spectrum of the excited radicals from the reaction zone of the plasma with the exhaust gases; Fig.2 - absorption spectrum in the infrared region of the AOI; in Fig.4 - absorption spectra in the infrared region are introduced into the reactor polymer: I - before cleaning, II - after cleaning; Fig.5 is a diagram of the installation for flue gas cleaning.Installation for purification of exhaust gas, which contains connected to the pipe 1 drain the last of the industrial plant reactor 2 with sections 3 generator 4 plasma and the device 5 of the reaction products with the pipe 6 of the clean gas discharge.According to the first embodiment, the plant is equipped with the device 7 is input into the reactor polymer in a powdered state, incorporate in its structure purify harmful components of exhaust gas, or their derivatives. The device 5 of the reaction products has a collection of 8 solid-phase reaction products from the nozzle 9 to remove them.According to the second embodiment of the installation device 5 of the reaction products is of the surface type plate (on the devil. not shown) installed directly in the reactor and is made of polymer, incorporate in its structure the aforesaid harmful components and their derivatives, or having a coating of the specified polymer.In both variants can install the latest Vesnoi low-temperature plasma and polymer, for example, through performed in the reactor 2 box 11.In the walls of the reactor 2 may be open 12 to monitor the effectiveness of cleaning, to select the optimal cleaning process, through automatic software link.To create a plasma of the gas to be purified, the installation may be provided with a desiccant 13, through which the generators 4 its input connected to the pipeline 1.Gas cleaning is carried out as follows.On the cleaned gas is fed to the reactor 2 through line 1 of the device 7 and the generator 4, act accordingly entered polymer, non-equilibrium low-temperature plasma with high speed, plasma may be generated in the reactor and/or irradiation, plasma and/or radiation, in particular UV), provide activation reactions and components of the purified gas and polymer over the whole cross section of the reactor. While in the cavity of the reactor 2 in the interaction of the flows generated ions and radicals, such as plasma-based nitrogen and inert gas and purified gas pulp and paper industry, ions: Na2+CO2+H2S+CH3SH+NO2+ radicals:N, O, OH, CH3SH, NO, N*, OH*NO*the organizations with the incoming polymer, the resulting purification of exhaust gas from harmful components: SO2CS2CH3SN, NO2etc. for example, in the above reactions or their analogs.When testing the claimed method of cleaning exhaust gases were studied composition at the inlet and outlet of the reactor (which was used to install 1 version). As a plasma-forming gas used natural gas or nitrogen with inert gases. In the spectrum of the radiation from the reaction zone are observed intensive bands of excited radicals (see Fig.1). As the injected polymer was used polymer powder obtained from a mixture of methane with argon plasma method, the structure of which is characterized by the presence of free radicals and high concentrations of paramagnetic centers.The composition of the exhaust gas was determined by absorption spectra in the infrared region.Absorption spectra of the exhaust gas before and after treatment are presented respectively in Fig. 2 and 3.From the comparison of these spectra, it follows that the harmful components are removed from the gas phase, because the absorption band of oxides of nitrogen, sulfur, mercaptans and other sulfur compounds are absent in the spectrum is liberizatsii is embedded in the structure of the injected polymer harmful components illustrated in Fig.4, which shows the absorption spectra of the polymer before the completion of the treatment process and at the reactor exit curves I and II. In the absorption spectrum of the polymer are observed intense bands that are characteristic of sulfur and nitrogen, previously missing in the spectrum of the injected polymer.The advantages of the invention are simultaneous purification of exhaust gases from sulfur, nitrogen, carbon, mercaptans, etc., sulfur compounds (e.g., CS2H2S) without the formation of toxic secondary products, high degree of purification from sulfur, nitrogen, mercaptans and carbon disulfide, the use of low-voltage equipment.It should also be noted that the installation (in both versions) has no complex and expensive components and equipment, simple and safe in operation (due to the low voltages required for plasma formation), reliable in performance, it has small dimensions and weight, easily installed on existing production process changes, has the possibility of increasing the flow rate of the purified gas to several hundred thousand m3/including through the use of blocks of parallel reactors. 1. The way to clean eating solid reaction products, cession and output the cleaned gas, characterized in that the reactor is additionally injected polymer, incorporate in its structure harmful components, or their derivatives and implement activation reactions of the purified gas and the plasma polymer and/or radiation.2. The method according to p. 1, characterized in that the introduction of the polymer carry out its injection in the powdered state.3. The method according to PP.1 and 2, characterized in that the plasma is blown into the reactor at a supersonic speed.4. The method according to PP.1 to 3, characterized in that the irradiation zone of interaction of gases, plasmas and polymers using ultraviolet radiation.5. The method according to PP.1 to 4, characterized in that the plasma is created from a pre-dried gas to be purified.6. The method according to PP.1 to 4, characterized in that the plasma is created from natural gas, nitrogen, inert gas or mixtures thereof.7. Installation for purification of exhaust gases containing connected to the pipeline reactor off-gases with plasma generators and the output of the reaction products, made in the form of a separator with a collection of solid-phase components, characterized in that it is provided with an input device in the reactor polievka under item 7, characterized in that each of the plasma generator is made in the form of a DC plasma torch with an adjustable gap between the electrodes.9. Installation according to p. 7, characterized in that the reactor with plasma generators made in the form of cascading plasma torch.10. Installation on PP.7 and 8, characterized in that each of the plasma generator is connected to an input to the pipeline of exhaust gases through the dryer.11. Installation on PP.7 to 10, characterized in that the input device of the polymer in the reactor is arranged to change the direction of entry of the polymer into the cavity of the reactor.12. Installation on PP.7 to 11, characterized in that it is provided with a source of ultraviolet radiation for irradiation zone of interaction of the exhaust gases with plasma and polymer.13. Installation of flue gas containing connected to the pipeline reactor off-gases with plasma generators and the output of the reaction products, characterized in that the last placed directly in the reactor in the form of surfaces such as plates made of polymer, incorporate in its structure harmful components and their derivatives, or having a coating of the specified polymer in the form of p is de arc plasma torch with an adjustable gap between the electrodes.15. Installation according to p. 13, characterized in that the reactor with plasma generators made in the form of cascading plasma torch.16. Installation on PP.13 and 14, characterized in that each of the plasma generator is connected to an input to the pipeline of exhaust gases through the dryer.17. Installation according to p. 15, wherein the plasma torch is connected with its input to the pipeline of exhaust gases through the dryer.18. Installation on PP.13 to 17, characterized in that it is provided with a source of ultraviolet radiation for irradiation of the reaction zone.
FIELD: cleaning gas emissions from organic compounds, polycyclic aromatic hydrocarbons in particular.
SUBSTANCE: proposed method includes exposure of gas emissions to ultraviolet radiation of electric discharge in working range of wave length at average density of light energy of 10-3-3x10-1 J/cm2; exposure is performed in presence of vapor of liquid to saturated vapor at temperature of gas emissions from 0°C to +250°C. Exposure is performed in spectral range of wave length of 300-400 nm. Used as working liquid is water with addition of ozone at concentration of 0.1-1000 mg/m3 or water with addition of sulfur oxides at concentration of 0.1-300 mg/m3.
EFFECT: enhanced efficiency of method; reduced power requirements.
5 cl, 1 dwg, 1 tbl