CN104759190B - The removing collection device of a kind of sulfur dioxide gas and removing collection method thereof - Google Patents

Abstract

The invention relates to a device for removing and collecting sulfur dioxide gas, which includes an oxygen-sulfur dissociator and a sulfur solid accumulator, the two are connected as a whole through a variable diameter joint; at the same time, the invention also provides a device for removing sulfur dioxide and collecting by-products by using the above-mentioned device The process method of sulfur, the sulfur dioxide gas is dissociated into sulfur atoms and oxygen anions by the oxygen sulfur dissociator, the sulfur solid aggregator separates the sulfur atoms and oxygen anions, and the sulfur atoms gather in the sulfur solid aggregator On the inner wall of the tube electrode, the oxygen negative ions generate oxygen and discharge it from the metal ventilation pipe. The device provided by the invention has the advantages of simple structure, low cost, low maintenance cost, simple installation, low voltage, low energy consumption, and high desulfurization efficiency; the method provided is scientific and reasonable, with simple steps and good operability, and can efficiently complete the desulfurization process, avoid Compared with the existing desulfurization technology, it has obvious advantages compared with the existing desulfurization technology.

Description

A device for removing and collecting sulfur dioxide gas and a method for removing and collecting the same

technical field

The invention relates to a waste gas treatment device and method, in particular to a device for removing and collecting sulfur dioxide gas and a method for removing it.

Background technique

With the development of human society, especially the rapid development of heavy industry, air pollution has become a serious global problem. Among air pollutants, man-made pollutants mainly come from fuel combustion and many industrial productions. The total coal consumption in my country is about 4 billion tons, accounting for 65.7% of the total energy consumption. Since coal and petroleum usually contain sulfur compounds, so Large amounts of sulfur dioxide are produced during combustion. When sulfur dioxide dissolves in water, it will form sulfurous acid (the main component of acid rain), which can irritate human respiratory organs and skin, cause diseases such as bronchitis and emphysema, and cause serious environmental pollution and social and economic losses.

In recent years, my country has continuously established and perfected laws and regulations on atmospheric environmental protection, the total amount control of coal consumption, and emission standards for air pollutants. At the same time, investment in air pollution control has also increased, and many control methods have emerged one after another. So far, the removal methods of sulfur dioxide are mainly divided into: wet method, semi-dry method and dry method.

Among the wet desulfurization technologies, the limestone-gypsum desulfurization process is the flue gas desulfurization technology commonly used in the world, accounting for more than 90% of the industry. In this method, limestone is used as the desulfurizer, and the absorbent slurry is sprayed into the absorption tower to make it fully contact and mix with the flue gas, and to wash the flue gas, so that the SO ₂ in the flue gas and the CaCO ₃ in the slurry and the drum A chemical reaction occurs with the forced oxidizing air that enters, and finally generates gypsum to achieve the purpose of desulfurization. This method has the advantages of fast desulfurization reaction speed, simple equipment and high desulfurization efficiency. However, the wet process generally suffers from severe corrosion, high operation and maintenance costs, and especially the problem of secondary pollution. Since the concentration of SO ₂ in the flue gas is always changing, it is difficult to accurately control the input amount of desulfurization agent lime powder or slurry, resulting in the absorption tower The absorption liquid in the gypsum cannot be in the best absorption state, which seriously affects the desulfurization rate and the quality of the gypsum, resulting in a soft structure and low use value of the gypsum, which cannot enter the consumer market. According to reports, there are hundreds of millions of tons of desulfurized gypsum piled up in thermal power plants, occupying more than one million mu of land, and it is still increasing, which has caused serious white pollution.

Semi-dry desulfurization technologies mainly include spray drying desulfurization, semi-dry and semi-wet desulfurization, powder-particle spouted bed desulfurization, flue injection desulfurization, etc. These methods generally have the characteristics of simple process equipment, no corrosion and serious blockage of equipment, easy operation and maintenance of equipment, and easy disposal of by-products. The dosage process is difficult to control, the automation requirements are relatively high, the absorption efficiency of the absorbent is low, and the desulfurization efficiency is also low.

Dry desulfurization mainly includes spray drying method, flue calcium spraying method, circulating fluidized bed method, catalytic oxidation method, charging method, copper oxide method, alkaline aluminate method, molten salt absorption method and plasma method. Among them, the plasma method is the method with the most research and the broadest development prospect in the dry desulfurization in the industry. Plasma can be classified into high-temperature plasma and low-temperature plasma according to temperature, and low-temperature plasma is further divided into hot plasma and cold plasma. Among them, when the particle temperature reaches 10 ⁶ ~10 ⁹ K, it belongs to high-temperature plasma, and when the particle temperature reaches from room temperature to 10 ⁴ K, it belongs to low-temperature plasma. In low-temperature plasma, when the temperature of heavy particles and the temperature of electrons reach a state of thermodynamic equilibrium, it is called thermal equilibrium plasma or thermal plasma, such as arc or high-frequency plasma; when the temperature of heavy particles is room temperature and the temperature of electrons reaches tens of thousands of degrees When , the temperature of heavy particles and the temperature of electrons are far from the thermal equilibrium state, which is called non-thermal equilibrium plasma or low-temperature plasma, such as glow discharge or microwave plasma.

In recent years, the low-temperature plasma method has become internationally recognized as a new method with great market potential and good application prospects. Low-temperature plasma methods mainly include electron beam irradiation method, pulsed corona discharge method, DC corona discharge method, dielectric barrier discharge method, dielectric packed bed discharge method, etc. The characteristic is that the temperature of electrons is much higher than that of heavy particles. Microwave discharge, corona discharge, silent discharge, and glow discharge are usually used to generate high-energy electrons and free radicals, ionize gas molecules, and trigger chemical reactions. As we all know, as the voltage increases, the DC discharge modes are initial streamer, glow, pre-breakdown streamer, and spark discharge. Glow discharge fills the entire electrode space, the current density is generally 1-5mA/cm ² , the entire gap still shows rising volt-ampere characteristics, and its average electron energy is 2-8eV. The current of glow discharge is several orders of magnitude higher than that of corona discharge. Due to the high energy consumption of glow and the small chemical effect, the average electron energy of corona discharge is less than 3eV, the average electron energy of spark discharge is about 1eV, and the macroscopic gas temperature Especially high, it is easy to burn the device, so the appearance of glow and spark discharge should be avoided in use. However, due to the low intensity of corona discharge and microwave discharge, the energy and concentration of active particles generated are low, and the efficiency of the chemical reaction excited is low, resulting in low gas treatment efficiency and poor practicability. Therefore, the research in the industry mostly focuses on the pulsed corona method.

The pulse corona method is to use the discharge between the corona and the air gap between the electrodes of the corona reactor, so that the electrons with high mobility are accelerated by a sudden strong electric field in the free path to obtain sufficient energy (higher than 8.4eV) To ionize the flue gas, obtain non _- equilibrium plasma at room temperature, and then oxidize and remove SO2. The biggest advantage of this method is that it can play the same role as the electron beam method and overcome the shortcomings of the electron beam method. It saves the expensive electron gun with high power and long-term stable work, and avoids the problems of electron gun life and X-ray shielding. Although the desulfurization efficiency of this method is high, the overall energy consumption is also high, and the frequency of the current pulse power supply is generally several hundred Hz, and the power of the power supply is only several hundred kW, which is far from meeting the requirements of industrial applications.

In order to solve the problems existing in the traditional pulsed corona method, with the continuous deepening of research, in recent years, scholars in the industry have also studied some methods that can generate streamer discharge to remove sulfur dioxide, such as superimposing the discharge electrode with AC and DC. The high voltage power supply is connected to generate the streamer discharge. Although these methods can prove the feasibility of streamer discharge, people are still unable to produce a high-frequency, high-power power supply with an AC frequency greater than 100kHz and a power greater than 1000kW, so that the generated streamer discharge power is relatively small. The device is complex, and it is only in the experimental stage, so it cannot be put into the practical application of industrial waste gas treatment. Therefore, it is an urgent problem in the industry to develop a device and method that can be used in the removal of sulfur dioxide from industrial flue gas with high desulfurization efficiency, low energy consumption, simple operation and maintenance, and no secondary pollution.

Contents of the invention

One of the purposes of the present invention is to provide a device for removing and collecting sulfur dioxide gas, so as to solve the problem that the current streamer discharge removing and collecting device has low power and complicated power supply devices, which cannot be put into industrial application, and the by-products produced have secondary pollution problem.

The second object of the present invention is to provide a method for removing and collecting sulfur dioxide gas, so as to solve the problems of cumbersome desulfurization process and low desulfurization efficiency of existing sulfur dioxide gas removal methods.

The object of the present invention is achieved like this: a kind of removal collection device of sulfur dioxide gas, comprises oxygen sulfur dissociator and sulfur solid accumulator;

The oxygen-sulfur dissociator includes a microwave resonant cavity, an insulator, a dissociated corona wire, a microwave generator, and a microwave shield. The microwave shield is respectively arranged at the upper and lower ends of the microwave resonant cavity. The upper and lower ends of the inner side of the shielding cover are respectively provided with an insulator, and the dissociation corona wire is fixedly arranged between the two insulators; the dissociation corona wire is located at the geometric center of the microwave resonator; the microwave The generator is arranged on the cavity of the microwave resonant cavity; the dissociated corona wire is connected to the positive pole of the power supply, and the microwave resonant cavity is connected to the negative pole of the power supply or grounded; the power supply is one of high-voltage direct current or pulsed direct current, and the The corona inception voltage of the power supply is 5 kV-40 kV; the voltage of the high-voltage DC power supply is 5 kV-50 kV; the voltage of the pulsed DC power supply is 5 kV-50 kV, and the frequency is 10 kHz-15 kHz;

The sulfur solid collector includes an outer sleeve, several bobbin electrodes, metal ventilation pipes, cooling liquid and an insulating sealing cover arranged on the upper part of the outer sleeve, the bobbin electrodes are arranged in the outer sleeve, the The metal ventilation tube is arranged at the center of each tube electrode, and the upper end of the metal ventilation tube passes through the insulating sealing cover. The metal ventilation tube and the tube electrode are insulated from each other and the connection voltage is 4 kV-20 kV DC respectively. Positive and negative poles of the power supply;

The lower end of the oxygen-sulfur dissociator is provided with a flue gas inlet, and the outer sleeve and the microwave resonant cavity are connected together with the sulfur solid collector through a variable-diameter joint.

The microwave generator described in the present invention comprises a magnetron and a waveguide, and the magnetron is one or several, and the several magnetrons are connected together through the waveguide; the frequency of the microwave generator is 915 MHz, the magnetron is set on the microwave resonant cavity through the waveguide.

In the present invention, the insulator is a ceramic insulator; the dissociated corona wire is a tungsten wire or a stainless steel wire; the microwave shield is a metal plate with small holes or a stainless steel mesh; the microwave resonator is made of stainless steel become.

In the present invention, the diameter of the outer sleeve is 1.5-2.5 times the diameter of the microwave resonant cavity, and the volume of the outer sleeve is 3-5 times the volume of the microwave resonant cavity.

The diameter of the microwave resonant cavity in the present invention is 30 cm-90 cm, and the radius of the dissociated corona wire is 0.5 mm-1.5 mm.

The inner wall of the tube electrode in the present invention is coated with a layer of elemental sulfur with a thickness of 0.5mm-1.5mm, which is used to more effectively induce the adsorption and dissociation of sulfur atoms.

In the present invention, a circulating cooling liquid is provided at the gap between the outer sleeve and the periphery of the bobbin electrode.

The present invention also provides a method for removing and collecting sulfur dioxide gas, comprising the following steps:

(a) Assemble the equipment according to the removal and collection device of sulfur dioxide gas; the diameter of the microwave resonant cavity is set to 30-90 cm, and the radius of the dissociated corona wire is 0.5 mm to 1.5 mm; the microwave generator The frequency is 915MHz; the diameter of the outer sleeve is 1.5-2.5 times the diameter of the microwave resonant cavity; several bobbin electrodes are arranged inside the outer sleeve, and the outer sleeve and the periphery of the bobbin electrodes The gap is provided with circulating coolant;

(b) A layer of elemental sulfur with a thickness of 0.5 mm to 1.5 mm is coated on the inner wall of the tube electrode;

(c) Turn on the power supplies of the oxygen-sulfur dissociator and the sulfur solid concentrator respectively, and apply a high-voltage direct current of 5 kV-50 kV or a pulsed direct current of 5 kV-50 kV with a frequency of 10 kHz-15 kHz to the oxygen-sulfur dissociator, and The corona inception voltage is 5 kV-40kV, and the microwave generator is started simultaneously; it is a DC power supply with a voltage of 4kV-20kV to the sulfur solid aggregator;

(d) Introduce the flue gas containing sulfur dioxide into the air inlet provided at the lower part of the oxygen-sulfur dissociator, the temperature of the flue gas is 150-250°C; the effect of making the sulfur dioxide in the flue gas streamer discharge in the oxygen-sulfur dissociator dissociate into sulfur atoms and oxygen negative ions;

(e) The dissociated sulfur atoms and oxygen negative ions are decompressed and cooled through the variable diameter joint, and enter the sulfur solid collector, and adjust the flow rate of the circulating cooling liquid in the sulfur solid collector, so that the temperature in the bobbin electrode can be controlled At 80-100°C, sulfur atoms gather to the inner wall of the bobbin electrode under the action of the direct current electric field force and the adsorption of sulfur crystal nuclei on the inner wall of the bobbin electrode, and the oxygen negative ions are combined to generate oxygen after collision, and are discharged through the metal ventilation pipe. The sulfur element accumulated on the inner wall of the tube electrode can be recovered.

In the step (d) of the present invention, the density of sulfur dioxide contained in the flue gas is controlled at 1.0-2.5 kg/m ³ ; the flow velocity of the flue gas is 0.1-0.164m/s.

In the step (a) of the present invention, 5-7 bobbin electrodes with a circular cross section are uniformly arranged inside the outer sleeve.

In step (a) of the present invention, there are preferably 7 package electrodes, and the outer diameter of each package electrode is 1/3 of the inner diameter of the outer sleeve.

The circulating cooling liquid in step (a) of the present invention is preferably deionized demineralized water.

The industrial dust removal in traditional research generally adopts the form of negative corona discharge, but what the present invention adopts is positive corona. The present invention adopts positive corona, which can achieve faster development speed, wider discharge extension range, stronger light intensity, brighter glow of corona discharge, and high-energy electrons produced under the same conditions of voltage and pole distance. Stronger and higher conversion rate of chemical reaction, at the same time, under the action of microwave field, polar molecules change from chaotic thermal motion to regular motion in the direction of electric field, interference and hindrance of intermolecular interaction force It plays a role similar to internal friction, converting the absorbed electric field energy into heat energy, and increasing the temperature of the dielectric. In this way, the microwave field not only uses microwaves to make polar molecules rotate, vibrate, and heat at high speed, but also converts As a high-frequency, high-power switching power supply, the microwave field modulates the DC corona into a pulsed corona with a certain frequency, producing streamer discharge.

The present invention combines the generated DC corona with the microwave field through the specific desulfurization collection device independently developed, through the setting of specific components, dimensions and parameters in the device, and the ingenious setting of the connected power supply voltage, frequency and microwave field. The high-energy electrons generated by the high-power streamer discharge in the oxygen-sulfur dissociator are used to dissociate the sulfur dioxide gas and promote the chemical reaction, and finally realize the invention goal of efficient desulfurization. It is proved by experiments that the desulfurization collection device provided by the present invention can realize streamer discharge power as high as 2-10 kW, and its desulfurization efficiency is as high as 98%, which is significantly improved compared with the existing desulfurization devices in the same field, and overcomes the existing desulfurization equipment. Due to the small power of the power supply and the small discharge power generated, the desulfurization efficiency is low and it cannot be popularized and applied in the industry; at the same time, the invention also cleverly designs the sulfur solid collector, which can reduce the decompression of the dissociated gas Cool down, under the action of the electric field force in the electrostatic field, S and O are separated to form elemental sulfur, and the sulfur solid is effectively recovered through the sulfur solid collector. It can be seen that the present invention not only realizes the efficient desulfurization treatment of sulfur dioxide gas, but also has no corrosion to the device, and can gather, recycle and recycle the sulfur solids produced by desulfurization without any pollution.

In addition, the present invention adopts the superposition of DC base voltage and microwave AC, which saves switching elements and complex circuits. The AC frequency is the microwave frequency of 915 MHz, and the higher the frequency, the higher the efficiency of streamer discharge. The magnetron that emits microwaves is used as the power supply. Its production and application technologies are very mature. The power of industrial microwave magnetrons ranges from 5 kW to 100 kW, and some have hundreds of kW. The components are few and the circuit is simple, and the advantages are obvious; , The microwave field itself also acts as a catalyst. The activation energy of the microwave decomposition reaction is 18 kJ/mol, which is much lower than that of the conventional thermochemical reaction, which can increase the desulfurization effect. Using the microwave field to generate streamer discharge can kill two birds with one stone. The invention adopts dry flue gas desulfurization, does not use sprayer device, drier, absorbent, etc., the device is simple and corrosion-free, and the recovered product elemental sulfur can be widely used as industrial raw material.

The process method matched with the desulfurization collection device provided by the present invention has simple steps, easy operation, convenient maintenance, high work efficiency, and can efficiently realize the purpose of high _- power streamer discharge to efficiently remove SO2 in exhaust gas, and can be easily Good recovery of solid sulfur, no secondary pollution, reusable. It can be seen that, compared with the traditional desulfurization method, the method provided by the present invention is a new desulfurization method that is simple, economical, low in energy consumption and high in efficiency.

The device provided by the invention has the advantages of simple structure, low cost, low maintenance cost, simple installation, low voltage used, high safety in use, low energy consumption, and high desulfurization efficiency; the method provided is scientific and reasonable, with simple steps, good operability, and high efficiency Completing the desulfurization process avoids the possibility of secondary pollution by by-products, and has significant advantages over existing desulfurization technologies.

Description of drawings

Figure 1 is a schematic structural view of the removal and collection device of the present invention.

Fig. 2 is a sectional view taken along line A-A of Fig. 1 .

Figure 3 is a diagram of the electric field distribution of the microwave resonator.

FIG. 4 is an electric field distribution diagram in the B-B direction of FIG. 3 .

In the figure: 1. Oxygen-sulfur dissociator, 2. Sulfur solid concentrator, 3. Reducing joint, 4. Dissociation corona wire, 5. Air inlet, 6. Microwave shielding cover, 7. Microwave resonant cavity, 8. Microwave generator, 9, insulator, 10, bobbin electrode, 11, metal ventilation pipe, 12, insulating sealing cover, 13, cooling liquid, 14, outer sleeve.

detailed description

The following examples are used to further describe the present invention in detail, but do not limit the present invention in any form.

Example 1

As shown in Figure 1, the device for removing and collecting sulfur dioxide gas provided in this embodiment mainly includes an oxygen-sulfur dissociator 1 and a sulfur solid collector 2; New device for electrolysis of sulfur dioxide gas and collection of solid sulfur.

The oxygen-sulfur dissociator 1 includes a cylindrical microwave resonant cavity 7 , an insulator 9 , a dissociation corona wire 4 , a microwave generator 8 and a microwave shield 6 . The microwave shielding cover 6 is respectively installed on the upper and lower ends of the microwave resonant cavity 7, and an insulator 9 is fixedly arranged at the upper and lower center positions of the inner side of the microwave shielding cover 7, and the dissociated corona wire 4 is fixedly installed on the two ends. between two insulators 9, and ensure that the dissociated corona wire 4 is located at the geometric center of the cylindrical microwave resonator 7; the microwave generator 8 is installed on the side wall of the cavity of the microwave resonator 7; its microwave generator includes a The frequency of the magnetron and the waveguide is 915 MHz, and the magnetron emits a microwave field into the microwave resonant cavity 7 through the waveguide. Wherein the dissociation corona wire 4 is connected to the positive pole of the power supply, the microwave resonant cavity 7 is connected to the negative pole of the power supply, and the lower end of the oxygen-sulfur dissociator 1 is provided with an air inlet 5 containing sulfur dioxide flue gas. The power supply connected to the dissociation corona wire 4 and the microwave resonator 7 is high-voltage direct current or pulsed direct current, and its corona inception voltage is 5-40 kV. If it is a high-voltage direct-current power supply, its voltage is 5-50 kV; if it is a pulsed direct-current power supply, its The voltage is 5-50 kV and the frequency is 10-15kHz.

The diameter of the above-mentioned microwave resonant cavity 7 needs to be set to 30-90cm, and the radius of the dissociated corona wire 4 is 0.5-1.5mm; the material of the above-mentioned insulator 9 is ceramic; the dissociated corona wire 4 is tungsten wire or stainless steel wire ; The microwave shield 6 is a metal plate with small holes or a stainless steel mesh; the microwave resonator 7 is made of stainless steel.

As shown in FIGS. 1 and 2 , the sulfur solid collector 2 includes an outer sleeve 14 , a bobbin electrode 10 , a metal ventilation pipe 11 and an insulating sealing cover 12 arranged on the upper part of the outer sleeve 14 . There are 5-7 bobbin electrodes 10 with a circular cross section, which can be evenly arranged in the outer sleeve 14. A metal ventilation pipe 11 is arranged at the center of each bobbin electrode 10, and the upper end of the metal ventilation pipe 11 passes through And higher than the insulating sealing cover 12, the metal ventilation pipe 11 and the bobbin electrode 10 are insulated from each other and respectively connected to the positive pole and the negative pole of the DC power supply. The voltage of the DC power supply is 4-20kV. A cavity that can be used to hold circulating cooling fluid 13 is formed between them.

The diameter of the outer sleeve 14 in the present invention is 1.5-2.5 times of the diameter of the microwave resonant cavity 7, and the volume of the outer sleeve 14 should be 3-5 times of the volume of the microwave resonant cavity 7.

According to the structural features of the above-mentioned device, assemble and prepare the removal and collection device for sulfur dioxide gas. When desulfurization, follow the steps below:

(1) A layer of elemental sulfur (sulfur) with a thickness of 1mm is coated on the inner wall of the bobbin electrode 10; place the sulfur in a metal container to add sulfur evenly, and when the temperature reaches the melting point of about 120°C, the sulfur will melt Become liquid sulfur with flowing properties, at this time, sulfur can be coated on the inner wall of the bobbin electrode 10, so that the dissociated sulfur atoms can be better induced to adsorb on the inner wall of the bobbin electrode 10, which is convenient for recycling;

(2) Turn on the power of the oxygen-sulfur dissociator 1 and the sulfur solid concentrator 2 respectively, and start the microwave generator at the same time when the oxygen-sulfur dissociator 1 is powered on; the power supply connected to the oxygen-sulfur dissociator is a high-voltage DC power supply or pulsed DC Power supply, its corona inception voltage is 5 kV -40 kV, if it is a high voltage DC power supply, its voltage is 5 kV -50 kV; if it is a pulsed DC power supply, its voltage is 5kV -50 kV, and its frequency is 10-15kHz; The power supply of the solid collector 2 is a DC power supply, and its voltage is 4 kV-20kV;

In operation, when DC high voltage or pulsed DC is added between the dissociation corona wire 4 and the microwave resonator 7, a corona will be generated between the microwave resonator body and the dissociation corona wire; The characteristics of the sinusoidal periodic conversion of the electric field and the magnetic field make the electric field generated by the microwave superimpose with the corona field, increase the electric field intensity in the microwave resonant cavity, and convert the corona discharge process into a streamer discharge with high chemical effect, and when the microwave field When the electric field in the medium is converted into a magnetic field, the superposition effect of the microwave electric field and the corona field ends, and the streamer discharge stops. In this way, a pulsed streamer discharge with a frequency related to the microwave frequency will be generated in the microwave resonator cavity, and the high-energy electrons of the streamer discharge will be used to process the sulfur dioxide gas into ionic sulfur and oxygen, because in the microwave field, the electric field and magnetic field are in a sinusoidal cycle Converted, assuming that the electric field is a positive half cycle, the magnetic field is a negative half cycle.

In the negative half cycle, when the sulfur dioxide gas enters the microwave resonant cavity, the corona field still generates corona at this time, and near the electrode with a small curvature radius, because the local electric field strength exceeds the ionization field strength of the gas, the gas is ionized and Excited, corona plasma appears. The energy distribution of free electrons in plasma is in the range of 2-20eV, while the electron energy required for dissociation and ionization of general electron bombardment gas molecules is in the range of 5-15eV, so corona discharge can dissociate part of SO ₂ , but the efficiency is limited . SO ₂ is a polar molecule. In the microwave field, regardless of the period, it rotates back and forth with the frequency of the microwave, causing the molecules to collide and rub each other, absorbing the energy of the microwave to increase the temperature and increase the density of the gas molecules. The collision frequency causes the gas to be excited, ionized, and finally breakdown to generate plasma. In the microwave field, the energy of high-energy electrons is _3-10eV , and the microwave energy is relatively small, and the effect of its energy dissociation SO2 is extremely limited. However, microwave has the function of catalyst, and the activation energy of microwave decomposition reaction is 18kJ/mol, which is far lower than that of conventional thermochemical reaction.

In the positive half cycle, when the microwave electric field and the corona field are superimposed, a streamer discharge will be generated between the positive and negative electrodes. "Preheating", its own energy has been improved, and at this time it is discharged by the streamer, the high-energy electrons collide with the gas molecules inelastically, ionize the gas molecules, generate electrons and strong oxidizing free radicals, and form a highly ionized Gas, electrons obtain energy through the electric field, and the energy of these high-energy electrons can reach 10-12eV. During the movement, they will collide with molecules, electrons and other particles in the resonant cavity, and part of the energy carried is converted into kinetic energy of the particles. The particles then collide with other particles to maintain the continuation of the discharge; another part of the energy is converted into the internal energy of the particles, causing the particles to ionize, excite, dissociate, and transform into active substances, a series of chemical reactions occur, and finally produce products and reaction heat;

(3) Introduce the flue gas containing sulfur dioxide into the air inlet 5 at the lower end of the oxygen-sulfur dissociator 1 through the induced draft fan, and control the flue gas flow rate at (0.4-2.5) /s range, the The wavelength of the microwave generated by the microwave generator, the density of sulfur dioxide in the flue gas is 1.0-2.5kg/m ³ , the temperature of the flue gas is 150-250°C, so that the sulfur dioxide in the flue gas is discharged in the oxygen-sulfur dissociator 1 Under the action, it dissociates into sulfur atoms and oxygen negative ions;

According to the article "Study on the Plasma Dissociation and Reaction Pathway of SO ₂ " by Sun Bin et al. (The electrons with * in the chemical formula are high-energy electrons):

The dissociation energy required to split an O ₂ molecule into two O atoms is 5.12eV, and the dissociation energy of SO ₂ is 5.65eV, so when the electric field of the microwave and the corona field are superimposed, a streamer discharge is generated, and its high-energy electron energy is enough to open the gas O ₂ , SO ₂ and other molecular chemical bonds, so as to realize the dissociation of sulfur and oxygen;

(4) The dissociated sulfur atoms and negative oxygen ions enter the sulfur solid concentrator 2, and since the bobbin electrode 10 and the metal ventilation pipe 11 apply DC high voltage, an electrostatic field is formed between the bobbin electrode 10 and the metal ventilation pipe 11 ; and sulfur atoms and oxygen negative ions enter the sulfur solid collector, through decompression and cooling, under the action of electric field force and crystal nucleus adsorption in the electrostatic field, S atoms and O negative ions move to the crystal nucleus and the positive electrode metal ventilation pipe respectively And gather, S atoms and O ions begin to separate; Oxygen negative ions release charges on the positive metal ventilation tube to generate oxygen atoms. After the oxygen atoms collide with the wall or other atoms, they will combine to generate oxygen, which will be discharged through the vent hole.

The collection process is as follows (M is other gas molecules or walls):

Sulfur atoms combine in pairs to form S ₂ , pressure drop and temperature drop cause the solubility of sulfur in the gas to decrease. As the temperature and pressure decrease, gaseous sulfur (S _{2 )} begins to liquefy _{. 6.} S ₈ exists in the form of a mixture. When the temperature is lower than 159°C, a heterogeneous reaction occurs on the surface of sulfur, and the sulfur solidifies into a S ₈ ring structure and forms a stable agglomerate (the so-called agglomeration refers to the process of van der Waals force , Self-adhesive force, adhesion force, capillary force and surface tension formed by the close contact between substances, the phenomenon that particulate matter is spontaneously and directionally linked together). Sulfur moves to the inner wall of the cylinder under the action of the attractive force of the crystal nucleus, attaches to the crystal nucleus and crystallizes to form insoluble sulfur.

The process of collecting S is as follows:

The gas discharged from each metal ventilation pipe 11 can be discharged directly or enter the next process after being collected and tested. The insoluble sulfur accumulated on the inner wall of the cylinder can be collected periodically.

At the same time, during the collection process, adjust the flow rate of the circulating cooling liquid 13 in the sulfur solid collector 2, so that the temperature in the bobbin electrode 10 is controlled at 80-100°C, and the sulfur atoms are adsorbed by the electric field force and the sulfur crystal nucleus on the inner wall of the bobbin electrode. Accumulate to the inner wall of the bobbin electrode 10, and the oxygen negative ions combine in pairs after collision to generate oxygen, which is discharged through the metal ventilation pipe 11, and the sulfur element accumulated on the inner wall of the bobbin electrode 10 can be recovered. During the operation, the temperature of the package electrode 10 is controlled within the range of 80-100°C. The main reason is that when the temperature is too high, the sulfur film coated on the inner wall of the package electrode 10 is easy to soften and fall off, and if the temperature is too low, it is easy to produce "condensation". ", which affects the crystallization of sulfur, and in addition, the tube electrode 10 can be designed in the form of two half tubes, which is convenient for taking out crystalline sulfur.

In practical applications, the device can set the diameter of the microwave resonator 7 to 32 cm, the height to 80 cm, the volume to be about 64300 cm ³ , the radius of the dissociated corona wire 4 to be 1 mm, and the distance between the dissociated corona wire 4 and the microwave resonator 7 The distance is 16cm, and the frequency of microwave generator ⁸ is 915MHz; the inner diameter of outer sleeve 14 is set to 68cm, the height is 70cm, and the volume is about 254100 cm Circular bobbin electrode 10; a circulating cooling liquid 13 is installed between the outer sleeve 14 and the bobbin electrode 10, and the cooling liquid 13 is preferably demineralized water; is 25kV, the DC voltage applied to the sulfur solid collector 2 is about 10kV, the density of the treated flue gas is about 1.3 kg/m ³ , the flue gas temperature is between 150-250°C, and the flue gas flow rate is less than or It is equal to 0.164 m/s. According to the above-mentioned desulfurization method, the power is turned on, and the flue gas is introduced, and streamer discharge is generated in the microwave resonant cavity 7. The electric field distribution of the microwave resonant cavity 7 along the longitudinal section of the center line is shown in Figure 3. Figure 3 The electric field distribution in the middle BB cross section is shown in Fig. 4. From known technical customers, it is calculated by the following formula:

Where V is the volume of the microwave resonator, and the energy utilization rate is taken as =75%; W ₀ : energy of a streamer discharge (0.3mJ); the height of the oxygen-sulfur dissociator is H ₁ , the diameter is D ₁ , v ₀ is the flue gas flow rate, and the flue gas flow rate is controlled at (0.4～2.5)λ /s, v is the streamer speed (about 2×10 ⁵ m/s).

The calculation results show that in this application, the energy consumption per unit volume of flue gas is about 17.86kJ/m ³ ~ 25.44kJ/m ³ , the microwave field contributes about 60%, the corona field contributes about 40%, and the streamer discharge The power is as high as 2-10 kW, and its desulfurization efficiency is as high as 98%.

Claims (8)

1. a removing collection device for sulfur dioxide gas, is characterized in that, including oxygen sulfur dissociator and sulfur solids accumulation device；

Described oxygen sulfur dissociator includes microwave cavity, insulator, dissociation corona wire, microwave generator and micro-wave screening cover,

Described micro-wave screening cover is separately positioned on the upper/lower terminal of described microwave cavity, inside described micro-wave screening cover Upper and lower end be respectively arranged with 1 insulator, be fixedly installed described dissociation corona wire between said two insulator；Described Dissociation corona wire is positioned at the geometric center of described microwave cavity；Described microwave generator is arranged on the chamber of described microwave cavity On body；

Described dissociation corona wire connects positive source, and described microwave cavity connects power cathode or ground connection；Described power supply is high straightening One in stream electricity or pulse direct current, the discharge inception voltage of described power supply is 5-40kV；The voltage of described high voltage direct current is 5- 50kV；The voltage of described pulse direct current is 5-50 kV, frequency is 10-15 kHz；

Described sulfur solids accumulation device includes outer sleeve, some bobbin electrodes, metal vents and is arranged on described outer sleeve The insulated enclosure lid in portion, described bobbin electrode is arranged in described outer sleeve, has arranged at described each bobbin electrode centers Stating metal vents, the upper end of described metal vents passes described insulated enclosure lid, described metal vents and bobbin electrode Mutually insulated and respectively connection voltage are positive pole and the negative pole of 4-20 kV DC source；

The lower end of described oxygen sulfur dissociator is provided with smoke air inlet, and described outer sleeve and described microwave cavity pass through reducer union Described oxygen sulfur dissociator is connected as a single entity with described sulfur solids accumulation device.

The removing collection device of sulfur dioxide gas the most according to claim 1, is characterized in that, described microwave generator bag Including magnetron and waveguide, described magnetron is one or several, and the frequency of described microwave generator is 915 MHz.

The removing collection device of sulfur dioxide gas the most according to claim 1, is characterized in that, described insulator is pottery Insulator；Described dissociation corona wire is tungsten filament or stainless steel silk；Described micro-wave screening cover is band foraminate metallic plate or stainless Steel wire netting；Described microwave cavity is that stainless steel material is made.

The removing collection device of sulfur dioxide gas the most according to claim 1, is characterized in that, the diameter of described outer sleeve Being 1.5-2.5 times of microwave cavity diameter, the volume of described outer sleeve is 3-5 times of described microwave cavity volume.

The removing collection device of sulfur dioxide gas the most according to claim 1, is characterized in that, described microwave cavity Diameter 30-90 cm, the radius of described dissociation corona wire is 0.5-1.5 mm.

The removing collection device of sulfur dioxide gas the most according to claim 1, is characterized in that, described bobbin electrode interior The thick elemental sulfur of one layer of 0.5-1.5 mm it is coated with on wall.

7. a removing collection method for sulfur dioxide gas, is characterized in that, comprise the following steps:

A () assembles the removing collection device of sulfur dioxide gas by claim 1；It is provided with the diameter of described microwave cavity 30-90 cm, the radius of described dissociation corona wire is 0.5-1.5 mm；The frequency of described microwave generator is 915 MHz；Described The diameter of outer sleeve is 1.5-2.5 times of microwave cavity diameter；Several bobbin electrodes it are provided with, in institute in described outer sleeve State and be provided with circulating cooling liquid between the outer wall of outer sleeve and bobbin electrode；

B () is coated with the elemental sulfur that one layer of 0.5-1.5 mm is thick on the inwall of described bobbin electrode；

C () is respectively turned on oxygen sulfur dissociator and the power supply of sulfur solids accumulation device, apply the height of 5-50 kV to described oxygen sulfur dissociator Pressure unidirectional current or 5-50 kV, frequency are the pulse direct current of 10-15 kHz, and its discharge inception voltage is 5-40 kV, starts micro-simultaneously Wave producer；The DC source that voltage is 4-20 kV is applied to described sulfur solids accumulation device；

D flue gas containing sulfur dioxide is introduced in the air inlet that described oxygen sulfur dissociator bottom is arranged by (), control the temperature of flue gas Degree, for 150-250 DEG C, makes the sulfur dioxide in flue gas dissociate into sulphur atom under the effect of described oxygen sulfur dissociator streamer-discahrge And negative oxygen ion；

(e) dissociate after sulphur atom and negative oxygen ion enter in described sulfur solids accumulation device, regulate in described sulfur solids accumulation device The flow velocity of circulating cooling liquid, makes the temperature in bobbin electrode control at 80-100 DEG C, and sulphur atom is at unidirectional current field force and bobbin electricity Assembling to described bobbin electrode inner wall under the effect of pole inwall sulfur nucleus absorption, negative oxygen ion combines generation two-by-two through collision rift Oxygen, is discharged by metal vents, and the sulfur simple substance that described bobbin electrode inner wall is assembled reclaims.

8. according to the removing collection method of sulfur dioxide gas described in claim 7, it is characterized in that, arrange in described outer sleeve Having 5-7 cross section is circular bobbin electrode.