WO2021243726A1 - 烟气脱硫、脱氮、脱汞净化方法和设备 - Google Patents

烟气脱硫、脱氮、脱汞净化方法和设备 Download PDF

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WO2021243726A1
WO2021243726A1 PCT/CN2020/094783 CN2020094783W WO2021243726A1 WO 2021243726 A1 WO2021243726 A1 WO 2021243726A1 CN 2020094783 W CN2020094783 W CN 2020094783W WO 2021243726 A1 WO2021243726 A1 WO 2021243726A1
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flue gas
denitrification
absorption
liquid
mercury removal
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French (fr)
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李敬业
李韬弘
李韬霖
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深圳市爱诺实业有限公司
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/46—Removing components of defined structure
    • B01D53/60—Simultaneously removing sulfur oxides and nitrogen oxides
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/46—Removing components of defined structure
    • B01D53/64—Heavy metals or compounds thereof, e.g. mercury
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/75—Multi-step processes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/77—Liquid phase processes
    • B01D53/78—Liquid phase processes with gas-liquid contact
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
    • B01D53/77—Liquid phase processes
    • B01D53/79—Injecting reactants
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J10/00—Chemical processes in general for reacting liquid with gaseous media other than in the presence of solid particles, or apparatus specially adapted therefor
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
    • B01J19/18—Stationary reactors having moving elements inside
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01C—AMMONIA; CYANOGEN; COMPOUNDS THEREOF
    • C01C1/00—Ammonia; Compounds thereof
    • C01C1/24—Sulfates of ammonium
    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
    • C01G13/00—Compounds of mercury
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2251/00—Reactants
    • B01D2251/10—Oxidants
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2251/00—Reactants
    • B01D2251/10—Oxidants
    • B01D2251/106—Peroxides
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2257/00—Components to be removed
    • B01D2257/60—Heavy metals or heavy metal compounds
    • B01D2257/602—Mercury or mercury compounds
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/02—Other waste gases
    • B01D2258/0283—Flue gases

Definitions

  • the invention relates to flue gas purification technology, in particular to a flue gas desulfurization, denitrification, and mercury removal purification method and equipment.
  • coal-fired boilers use a large number of wet flue gas desulfurization devices for SO 2 control, and the efficiency can reach more than 95%; for NO X control, conventional control methods include: selective non-catalytic SNCR and selective catalytic SCR technology.
  • SNCR technology is cost-effective low NO X control, but the removal efficiency is generally only reach 50% -65%. Therefore, in order to meet the requirements of environmental protection emissions, that is, to remove SO 2 , NO X , dust and mercury in the flue gas, coal-fired boilers need to be equipped with at least two independent desulfurization and denitrification systems. At the same time, it is also necessary to add special dust removal and denitrification systems.
  • Mercury equipment as a result, the entire equipment system is huge, complex, low energy efficiency, and covers a large area, high investment, high operating costs, and it is not easy to use.
  • SCR is the current commercial technology is the most effective low NO X control technology, can reach more than 80% of the nitrogen removal efficiency, but its initial investment at 490-1250 / kw, very expensive, running costs of about 2100 to 2800 yuan / ton NO X , if SCR technology is introduced on the basis of wet desulfurization, it will inevitably increase a huge amount of investment and operating costs, and the gains outweigh the losses.
  • the integrated process for removing SO 2 , NO x and mercury at the same time has the advantages of simple equipment, convenient management and operation, small footprint, and low investment and operating costs. Therefore, the combined flue gas desulfurization, denitrification and mercury removal technology has become an important part of current air pollution control. research direction.
  • the urea method has the following advantages: the final product is N 2 , CO 2 , and ammonium sulfate, and the product can be directly discharged. Ammonium sulfate can be made into fertilizer to recycle nitrogen and sulfur resources. Therefore, this method has certain research value.
  • the current technical situation is: this method can achieve high desulfurization efficiency, but the denitrification efficiency is not ideal. It is only suitable for treating pure nitrogen oxide exhaust gas.
  • the oxidation degree of NO x in the actual flue gas is very low, and the content of NO accounts for NO x. It is difficult to achieve high denitrification efficiency when the urea method is directly applied to flue gas purification. Therefore, people are pursuing the purpose of adding various chemical additives to the urea solution to improve the denitrification efficiency. However, studies have found that cheap additives do not greatly improve the denitrification efficiency, and only the addition of high-priced additives can achieve better denitrification efficiency. Therefore, Increasing the operating cost of the urea method, and due to the complexity of the additive components added, it will increase the manufacturing cost of the additive and the difficulty in the treatment of desulfurization and denitrification wastewater.
  • urea additive wet flue gas simultaneous desulfurization and denitrification method discloses a wet flue gas simultaneous desulfurization and denitrification method.
  • the invention uses urea as an absorbent and adds a certain amount of organic amine or phosphate additives , The content of urea is 5-30%, organic amine additives use ethylenediamine or triethanolamine; phosphate additives use ammonium phosphate (or sodium) or diammonium phosphate (or sodium), the concentration is (50 ⁇ 500) ⁇ 10-4%.
  • the removal rate of SO 2 is over 95%, and the removal rate of NO x is over 80%.
  • Organic amine additives are a kind of highly corrosive, highly irritating and toxic chemicals.
  • the product vapor is strongly irritating to mucous membranes and skin. Contact with the product vapor can cause conjunctivitis, bronchitis, pneumonia or pulmonary edema, and contact dermatitis may occur. Can cause liver and kidney damage. Direct contact with the skin and eyes can cause burns.
  • This product can cause occupational asthma, is harmful to the environment, and can cause pollution to water bodies. Therefore, large-scale industrial application of ethylene diamine is unacceptable, and it is difficult to realize industrial application.
  • the invention patent 201510681266.1 discloses a method for removing elemental mercury in coal-fired flue gas.
  • the removal of mercury in this method is carried out in a wet flue gas desulfurization spray absorption tower, and the prepared absorbent is sprayed from the upper part of the spray absorption tower Next, spray the coal-fired flue gas introduced from the flue port at the lower part of the spray absorption tower, so that the elemental mercury in the coal-fired flue gas fully reacts with the absorbent to realize the conversion of elemental mercury to divalent mercury;
  • the absorbent includes an oxidizing additive and a magnetic catalyst, the mass ratio of the oxidizing additive to the magnetic catalyst is 2-5:1, and the oxidizing additive is potassium peroxymonosulfate composite salt, sodium persulfate, sodium perborate, perborate
  • the catalyst is bismuth ferrite, cobalt doped bismuth ferrite, cobalt/lanthanum doped bismuth ferrite, cobalt/
  • Invention patent 201810191344.3 discloses a wet flue gas oxidative desulfurization, denitrification and mercury removal process based on electrode catalytic oxidant.
  • the method uses potassium persulfate or sodium persulfate as a strong oxidant for wet oxidation, and the anode plate in the electrochemical reaction tank and The cathode plate is a plated composite electrode plate with metallic titanium as the base material.
  • the process is complicated and the operating cost is high, which is difficult to realize industrial-scale applications.
  • the technical problem to be solved by the present invention is to provide a flue gas desulfurization, denitrification, and mercury removal purification method and equipment to solve the complex process existing in the existing flue gas purification technology, and the high operating cost is difficult to achieve industrial scale.
  • the problem is to provide a flue gas desulfurization, denitrification, and mercury removal purification method and equipment to solve the complex process existing in the existing flue gas purification technology, and the high operating cost is difficult to achieve industrial scale.
  • the present invention solves the above technical problems and proposes a flue gas desulfurization, denitrification, and mercury removal purification method, which includes the following steps:
  • the carbon dioxide from the flue gas is dissolved in water from the gas phase to carry out the carbonation reaction, and the gas/liquid two-phase equilibrium of the CO 2 -H 2 CO 3 -HCO 3-system is established;
  • the weakly alkaline absorbent containing strong oxidizing free radicals is composed of peroxy bicarbonate ions, hydroxyl radicals, carbonate anion radicals, hydroperoxy radicals, superoxide anion radicals, urea, peroxy
  • One or more components of hydrogen oxide and bicarbonate have a homogeneous mixed solution with a pH of 7-9.
  • pH value is 7.6 ⁇ 0.2.
  • the present invention also proposes a flue gas desulfurization, denitrification, and mercury removal purification equipment, including: a primary power wave absorption reactor, a carbon dioxide catalytic reactor, a secondary power wave fine purifier, an ammonium sulfate recovery system, and a mercury sulfide recovery system And waste water circulation and treatment system; the carbon dioxide catalytic reactor is arranged between the primary power wave absorption reactor and the secondary power wave fine purifier; the carbon dioxide catalytic reactor is used for production, storage and transportation of strong oxidation A weakly alkaline absorbent of free radicals.
  • the first-stage dynamic wave absorption reactor includes a double-layer dynamic wave absorption tower, a downstream static mixer, a circulating absorption liquid storage tank, and a circulating delivery system for a weakly alkaline absorption liquid containing strong oxidation radicals.
  • the two-layer kinetic wave absorption tower is provided with two nozzles arranged in two independently arranged upper and lower layers; the space above the two nozzles forms two absorbing foam layers during operation.
  • the circulating absorption liquid outlet under the circulating absorption liquid storage tank is in communication with the water inlet of the second nozzle of the double-layer dynamic wave absorption tower through a circulating water pipe and an absorption liquid circulating pump.
  • the outlet of the weakly alkaline absorption liquid delivery pump containing strong oxidation radicals from the carbon dioxide catalytic reactor is in communication with the water inlet of the first nozzle of the double-layer dynamic wave absorption tower; the circulating absorption liquid storage tank is connected with The static mixer is connected.
  • the one-stage kinetic wave absorption reactor further includes a co-current static mixer, and the inlet of the co-current static mixer is in communication with the bottom of the double-layer kinetic wave absorption tower; the co-current static mixer passes The connecting pipe and the connecting pipe are connected to the sump, the connecting pipe is connected to the lower part of the sump, the connecting pipe is connected to the upper part of the sump, the inside of the connecting pipe is liquid-phase absorption liquid; the inside of the connecting pipe What flows is a gas-liquid mixed phase.
  • two nozzles arranged independently in upper and lower layers are arranged inside the double-layer dynamic wave absorption tower.
  • the integrated purification method and equipment for flue gas desulfurization, denitrification, and mercury removal realized by the present invention uses carbon dioxide (CO2) in the flue gas to catalyze percarboxamide to generate a reaction-free selective oxygen-enriched activated radical-peroxy hydrogen carbonate Radical radicals (HCO4-), an integrated method and equipment for simultaneous desulfurization, denitrification and mercury removal from the flue gas of coal-fired boilers. It has high energy efficiency, stable operation, low investment, low operating cost, strong applicability, and energy. Realize the advantages of "zero emission", no secondary pollution and by-product resources. .
  • Fig. 1 is a flow chart of an integrated purification process for flue gas desulfurization, denitration, and mercury removal provided by an embodiment of the present invention.
  • Figure 2 is a process flow diagram of the ammonium sulfate recovery system.
  • One aspect of the present invention provides an integrated high-efficiency purification method for flue gas desulfurization, denitrification, and mercury removal.
  • Carbon dioxide is used to catalyze percarboxamide to generate a weakly alkaline absorption solution containing a variety of strong oxidizing free radicals to achieve rapid absorption in flue gas. of SO 2, NO x, while the oxidation of elemental mercury Hg 0 divalent easily absorbed mercury Hg 2+ chemical reaction.
  • the absorption liquid containing weakly basic radical is a strong oxidizing peroxy bicarbonate ions (HCO 4 -), hydroxyl radical (OH ⁇ -), carbonate radical anion (CO 3 ⁇ -), hydroperoxide oxygen radical (HO 2 ⁇ -), superoxide anion radical (O 2 ⁇ -), urea, hydrogen peroxide and bicarbonate (HCO 3 -) composed of a weakly basic pH of 7 to 9 are Phase mixed solution
  • Catalyze the reaction of carbon dioxide amides are: first generate peroxy bicarbonate ions in the catalytic carbon dioxide (HCO 4 -), peroxy bicarbonate ions further decomposed into hydroxyl radical (OH ⁇ -) and carbonate Root anion radicals (CO 3 ⁇ - ), which further react with hydrogen peroxide to generate hydroperoxide radicals (HO 2 ⁇ - ), and hydroperoxide radicals can be decomposed into superoxide anion radicals (O 2 ⁇ - ).
  • HCO 4 - catalytic carbon dioxide
  • CO 3 ⁇ - carbonate Root anion radicals
  • hydroperoxide radicals HO 2 ⁇ -
  • hydroperoxide radicals can be decomposed into superoxide anion radicals (O 2 ⁇ - ).
  • the peroxybicarbonate radical is an oxygen-rich activated radical with strong oxidizing properties and no reaction selectivity.
  • the characteristic of this activated radical is that its reactivity is more than 100 times that of hydrogen peroxide. .
  • the pH value of the reaction is neutral or weakly alkaline and weakly corrosive conditions with a pH of 7-9.
  • the peroxybicarbonate radical is a reaction product produced by carbon dioxide (CO 2 ) in the flue gas catalyzed by percarbonamide according to the reaction equations (4), (5), and (6). This reaction is in a protic solvent And aprotic solvents are very easy to occur.
  • the hydrogen peroxide is a product (4) produced by the decomposition of percarbamide CO(NH 2 ) 2 H 2 O 2 (urea peroxide) in an aqueous solution;
  • the percarboxamide is an adduct formed by directly connecting urea and hydrogen peroxide by hydrogen bonding, and is a new type of solid hydrogen peroxide (H 2 O 2 content ⁇ 35%) stable carrier.
  • the theoretical active oxygen content of percarboxamide is 16.0%, and the H 2 O 2 content is 35.0%; the molecular formula is CO(NH 2 ) 2 H 2 O 2 .
  • the integrated high-efficiency purification method of flue gas desulfurization, denitrification, and mercury removal based on peroxybicarbonate radicals described in this embodiment is realized by a two-stage dynamic wave absorption purification system.
  • the two-stage power wave absorption and purification system includes: a first-stage power wave absorption reactor, a carbon dioxide catalytic reactor, a second-stage power wave fine purifier, an ammonium sulfate recovery device, a mercury sulfide recovery device, and a wastewater treatment cycle system.
  • the structure of the first-stage kinetic wave absorption reactor is shown in Figure 1, including: 1.0 washing absorption tube, 1.1 flue gas inlet, 1.2 first nozzle, 1.3 first absorbing foam layer, 1.4 second absorbing foam layer, 1.5 The second nozzle, 1.6 absorption liquid circulating pump, 1.7 static mixer, 1.8 blowdown outlet, 1.9 two-phase communication pipe, 1.10 inertial separation chamber (gas-liquid separation zone), 1.11 absorption liquid storage tank, 1.12 liquid membrane separator, 1.13 smoke Gas outlet, 1.14 circulating absorption liquid outlet, 1.15 absorption liquid connecting pipe, 1.16 absorption liquid delivery pipe, 1.17-1.19 absorption liquid control valve, 1.20 absorption liquid circulation pipe, 1.21 absorption liquid circulation control valve, 1.22 absorption liquid recovery control valve and other components .
  • the washing absorption pipe 1.0 is installed vertically, the top is a gas inlet 1.1, and the lower part is provided with a circulating absorption liquid delivery pipe 1.16.
  • the circulating absorption liquid delivery pipe 1.16 is connected to the inlet (1.17-1.18) of the second nozzle 1.5 and the inlet of the first nozzle 1.2. Entrance (1.19).
  • the nozzles 1.2 and 1.5 adopt large-aperture non-throttling open-hole spray nozzles.
  • the feature of the open-hole spray is that the sprayed liquid does not atomize, the amount of liquid mist in the exhaust gas is very small, and the residual liquid can be removed by using a conventional gas-liquid separator.
  • the washing absorption tube 1 is connected to the inertial separation chamber 1.10 via a static mixer 1.7.
  • the mixer 1.7 is located below the second nozzle 1.5, which makes the gas-liquid two phases flowing in the co-current flow to perform turbulent mixing again, playing the role of co-current washing.
  • the static mixer 1.7 and the sump 1.11 are connected through a connecting pipe 1.9 and a connecting pipe 1.15, the connecting pipe 1.15 is connected to the lower part of the sump 1.11, the connecting pipe 1.9 is connected to the upper part of the sump 1.11, and the connecting pipe 1.15 is inside
  • the liquid phase absorbing liquid is flowing, and the gas-liquid mixed phase (flue gas + absorbing liquid) flows in the connecting pipe 1.9.
  • the top of the sump 1.11 is a purified flue gas outlet 1.13, the upper part is provided with a tangential inlet connected with a connecting pipe 1.9, and the bottom is provided with a circulating washing liquid outlet 1.12.
  • the upper part of the sump 1.11 is a gas-liquid centrifugal separation zone 1.10, and the lower part It is the catchment area.
  • the flue gas to be purified enters the scrubbing pipe 1.0 from top to bottom at a high speed from the flue gas inlet 1.1, and the scrubbing absorption liquid is sprayed into the air flow from bottom to top through the first nozzle 1.2 of the special structure through the circulating water pump, resulting in a two-phase high speed of gas and liquid.
  • a highly turbulent foam zone 1.3 is formed in the foam zone 1.3.
  • the gas and liquid phases are in high-speed turbulent contact, and the contact surface area is large, and these contact surfaces are constantly in contact with each other. Get rapid renewal to achieve high-efficiency foam washing and absorption effects.
  • the purified gas is separated from the scrubbing absorption liquid for the first time in the inertial separation zone of the static mixing element 1.7. After being separated due to inertia, most of the scrubbing absorption liquid enters the liquid collection area under the sump 1.11 through the connecting pipe 1.15, and is entrained.
  • the gas of the liquid foam enters the centrifugal separation area on the upper part of the liquid collecting tank 1.11 through the connecting pipe 1.9 in a tangential direction.
  • the gas-liquid two phases are separated again, and the flue gas after two-stage washing and two-stage separation and thoroughly purified is discharged from the flue gas outlet 1.13.
  • the power wave scrubber the power wave circulation pump, the gas-liquid separation tower, the absorption circulation pump, the sprayer, the cyclone demister, and the wet electrostatic precipitator, are all in the prior art in the technical field Conventional technology products.
  • the concentration of SO 2 , NO x and Hg0 in the flue gas at the inlet of the primary dynamic wave absorption reactor are respectively 2000ppm, 400ppm and 50 ⁇ g/Nm 3 , the flue gas concentration: 12g/Nm 3, and the flue gas inlet temperature is 100°C.
  • the liquid-to-air ratio is 0.6L/Nm 3
  • the concentration of percarbonamide in the absorption solution is 50mg/L
  • the pH of the solution is 7.6, and the temperature of the solution is 70°C.
  • the result of the small test is: the flue gas at the outlet of the first-stage kinetic wave absorption reactor
  • the simultaneous removal efficiency of SO 2 , NO x , Hg0 and dust can reach 99.2%, 98.5%, 95% and 99.9%, respectively.
  • the concentrations of SO 2 , NO x and Hg0 in the flue gas at the inlet of the primary dynamic wave absorption reactor are respectively 2000 ppm, 400 ppm and 50 ⁇ g/Nm 3 , the dust concentration: 12 g/Nm 3, and the temperature is 100°C.
  • the liquid-to-air ratio is 0.8L/Nm 3
  • the concentration of percarbonamide in the absorption solution is 50mg/L
  • the pH of the solution is 7.6, and the temperature of the solution is 70°C.
  • the result of the small test is: the flue gas at the outlet of the first-stage kinetic wave absorption reactor
  • the simultaneous removal efficiency of SO 2 , NO x , Hg0 and dust can reach 100%, 100%, 96% and 99.9% respectively.
  • the concentrations of SO 2 , NO x and Hg0 in the flue gas at the inlet of the primary dynamic wave absorption reactor are 2000 ppm, 400 ppm and 50 ⁇ g/Nm 3 , respectively, the dust concentration: 12g/Nm 3, and the flue gas temperature is 100 °C.
  • the liquid-to-air ratio is 0.8L/Nm 3
  • the concentration of percarbonamide in the absorption solution is 60mg/L
  • the pH of the solution is 7.2
  • the temperature of the solution is 70°C.
  • the result of the small test is: the flue gas at the outlet of the first-stage kinetic wave absorption reactor
  • the simultaneous removal efficiency of SO 2 , NO x , Hg0 and dust can reach 100%, 100% and 100%, 100% respectively.
  • the concentrations of SO 2 , NO x and Hg0 in the flue gas at the inlet of the primary dynamic wave absorption reactor are respectively 2000ppm, 400ppm and 50 ⁇ g/m 3 , soot concentration: 12g/Nm 3, and flue gas temperature is 100 °C.
  • the liquid-to-air ratio is 0.9L/Nm 3
  • the concentration of percarbonamide in the absorption solution is 80mg/L
  • the solution pH is 7.5
  • the solution temperature is 70°C.
  • the result of the small test is: the flue gas at the outlet of the first-stage kinetic wave absorption reactor
  • the simultaneous removal efficiency of SO 2 , NO x , Hg0 and dust can reach 100%, 100%, 100% and 100% respectively.
  • the concentrations of SO 2 , NO x and Hg0 in the flue gas at the inlet of the primary dynamic wave absorption reactor are respectively 2000ppm, 400ppm and 50 ⁇ g/m 3 , soot concentration: 12g/Nm 3, and flue gas temperature is 100 °C.
  • the liquid-to-air ratio is 1.0L/Nm 3
  • the concentration of percarbonamide in the absorption solution is 100mg/L
  • the pH of the solution is 7.6, and the temperature of the solution is 70°C.
  • the result of the small test is: the flue gas at the outlet of the first-stage kinetic wave absorption reactor
  • the simultaneous removal efficiency of SO 2 , NO x , Hg0 and dust can reach 100%, 100%, 100% and 99% respectively.
  • the concentrations of SO 2 , NO x and Hg0 in the flue gas at the inlet of the primary dynamic wave absorption reactor are 2000 ppm, 400 ppm and 50 ⁇ g/Nm 3 , respectively, the dust concentration: 12g/Nm 3, and the flue gas temperature is 100 °C.
  • the liquid-to-air ratio is 0.6L/m 3
  • the concentration of percarbonamide in the absorption solution is 60mg/L
  • the pH of the solution is 7.8, and the temperature of the solution is 70°C.
  • the result of the small test is: the flue gas at the outlet of the first-stage kinetic wave absorption reactor
  • the simultaneous removal efficiency of SO 2 , NO x , Hg0 and dust can reach 100%, 100%, 100% and 100% respectively.
  • the concentrations of SO 2 , NO x and Hg0 in the flue gas at the inlet of the primary dynamic wave absorption reactor are 2000ppm, 400ppm and 50 ⁇ g/Nm 3, respectively , and the flue dust concentration: 12g/Nm 3 ,, the flue gas outlet temperature It is 100°C.
  • the liquid-to-air ratio is 0.6L/m 3
  • the concentration of percarbonamide in the absorption solution is 60mg/L
  • the pH of the solution is 7.6, and the temperature of the solution is 70°C.
  • the result of the small test is: the flue gas at the outlet of the first-stage kinetic wave absorption reactor
  • the simultaneous removal efficiency of SO 2 , NO x , Hg0 and dust can reach 100%, 100%, 100% and 100% respectively.
  • the flue gas flow rate is 1,900,000 Nm 3 /h
  • the SO 2 , NO x and Hg0 concentrations in the flue gas at the inlet of the primary dynamic wave absorption reactor are 1700 mg/Nm3, 500 mg/Nm3 and 30 ⁇ g/Nm 3
  • soot concentration 11g/Nm 3
  • the flue gas temperature is 100°C.
  • the liquid-to-air ratio is 0.6L/Nm 3
  • the concentration of percarbonamide in the absorption solution is 80mg/L
  • the solution pH is 7.6, and the temperature of the absorption solution is 70°C.
  • the result of the small test is: the first-stage kinetic wave absorption reactor outlet smoke
  • the simultaneous removal efficiency of SO 2 , NO x , Hg0 and dust in the gas can reach 100%, 100%, 100% and 99.9% respectively.
  • Table 1 is the design data of 600MW coal-fired units.
  • the flue gas flow rate is 1050,000 Nm 3
  • the SO 2 , NO x and Hg0 concentrations in the flue gas at the inlet of the primary dynamic wave absorption reactor are 6500mg/Nm3, 500mg/Nm3 and 20 ⁇ g/ Nm 3
  • the flue gas temperature is 100°C.
  • the liquid-to-air ratio is 0.6L/Nm 3
  • the concentration of percarbonamide in the absorption solution is 80mg/L
  • the solution pH is 7.6, and the temperature of the absorption solution is 70°C.
  • the result of the small test is: the first-stage kinetic wave absorption reactor outlet smoke
  • the simultaneous removal efficiency of SO 2 , NO x , Hg0 and dust in the gas can reach 100%, 100%, 100% and 99.9% respectively.
  • Table 2 is the design data of a 300MW coal-fired unit.
  • the concentration of the percarbonamide in the absorption solution is 80 mg/L;
  • the pH of the weakly alkaline absorption solution containing multiple strong oxidizing free radicals is controlled at 7.6;
  • the flue gas flow rate in the throat of the power wave scrubber is 25 m/s;
  • the liquid-gas ratio of the power wave scrubber is 0.6 L/m 3 , that is, 0.6 liters of circulating absorption liquid is required for 1 standard cubic meter of flue gas.
  • the second aspect of the present invention provides a flue gas desulfurization, denitrification, and mercury removal integrated high-efficiency purification equipment as shown in Figure 1, including: a first-level dynamic wave absorption reactor, a carbon dioxide catalytic reactor, and a second-level dynamic wave fine purification Reactor, ammonium sulfate recovery system, mercury sulfide recovery system and wastewater recycling and treatment (zero discharge) system.
  • a carbon dioxide catalytic reactor is arranged between the primary dynamic wave absorption reactor and the secondary dynamic wave fine purifier, and the carbon dioxide catalytic reactor is a production, storage, and delivery system for a weakly alkaline absorbent containing strong oxidizing free radicals
  • the first-stage dynamic wave absorption reactor includes a double-layer dynamic wave absorption tower 1.0, a downstream static mixer 1.7 and a circulating absorption liquid storage tank 1.11.
  • the double-layer dynamic wave absorption tower 1.0 is vertically and fixedly installed on the top of the static mixer 1.7; the bottom of the double-layer dynamic wave absorption tower 1.0 is connected to the inlet of the static mixer 1.7, and the top of the double-layer dynamic wave absorption tower 1.0 is the flue gas inlet 1.1;
  • the static mixer 1.7 is connected with the absorption liquid connecting pipe 1.15, the two-phase communication pipe 1.9 and the absorption liquid storage tank 1.11;
  • the two-layer dynamic wave absorption tower 1.0 is provided with nozzles 1.2 and 1.5 arranged in two layers; the space above the two nozzles forms two absorbing foam layers during operation, as shown in FIG.
  • the circulating absorption liquid outlet is communicated with the water inlet 1.18 of the second (lower) nozzle 1.5 of the double-layer dynamic wave absorption tower through the circulating water pipe 1.20 and the absorption liquid circulating pump 1.6; the said from carbon dioxide
  • the outlet 2.10 of the weakly alkaline absorption liquid delivery pump 2.9 containing strong oxidation radicals of the catalytic reactor is connected to the water inlet 1.19 of the first (upper) nozzle 1.2 of the double-layer dynamic wave absorption tower;
  • the top of the circulating absorption liquid storage tank is fixedly installed with a
  • the gas-liquid two-phase contact area is extremely large and continuously updated, so that extremely high heat and mass transfer efficiency can be obtained.
  • the carbon dioxide catalytic reactor 2 includes: flue gas (carbon dioxide) inlet pipe 2.6, flue gas outlet pipe 2.7, absorption liquid storage tank 2.0, (pH regulator) ammonium bicarbonate feeding device 2.1, and percarbonamide feeding device 2.2 , Stirrer 2.3, absorption liquid pH adjustment control system 2.4, first-level dynamic wave absorption reactor absorption liquid delivery pump 2.9, second-level dynamic wave fine purifier absorption liquid delivery pump 2.12, first-level dynamic wave absorption reactor absorption liquid regulating valve 2.10 and the second-level dynamic wave fine purifier absorption liquid regulating valve 2.11 );
  • the outlet of the desalinated water pump 2.15 is connected to the inlet of the desalinated water inlet control valve 2.14 of the high-level desalinated water tank 2.13; the desalinated water outlet 2.17 of the high-level desalinated water tank 2.13 is connected to the desalinated water inlet 2.18 of the carbon dioxide catalytic reactor absorption liquid storage tank 2.0 .
  • the percarboxamide supply equipment includes: a percarboxamide storage bin, a screw automatic feeder, and an absorption liquid storage tank;
  • the ammonium bicarbonate supply equipment includes: ammonium bicarbonate storage bin, screw automatic feeder, absorption liquid storage irrigation and pH adjustment control system 2.4.
  • the flue gas inlet pipe 2.6 is connected to the outlet of the flue gas circulation fan 2.19, the inlet of the flue gas circulation fan is connected to the secondary power wave fine purifier flue gas bypass outlet 2.20, and the flue gas outlet pipe 2.7 is connected to The flue gas inlet of the secondary dynamic wave fine purifier 3.1.
  • the secondary power wave fine purifier includes: secondary power wave fine purifier absorption tower 3.0, flue gas inlet 3.1, flue gas distribution network 3.2, secondary power wave fine purifier washing liquid storage tank 3.3, secondary power wave Washing liquid drain port 3.4, washing liquid circulating pump inlet control valve 3.5, washing liquid circulating pump 3.6, washing liquid control valve 3.7, washing liquid inlet 3.8, washing liquid nozzle 3.9, washing foam layer 3.10, flue gas distribution network 3.11, flue gas Outlet diffusion cone 3.12, demister 3.13, purified flue gas outlet (to the chimney) 3.14.
  • the characteristics of the secondary power wave fine purifier are: the flow direction of the flue gas is from bottom to top, and the washing liquid is sprayed in the reverse direction from top to bottom; the washing liquid of the secondary power wave fine purifier is derived from the catalytic reaction of carbon dioxide
  • the ammonium sulfate recovery system is shown in Figure 2, including: sulfuric acid high tank 4.4, sulfuric acid replenishment pipeline 4.5, spray saturator 4.6, heating flue gas inlet 4.7, heating flue gas outlet 4.8, and ammonium sulfate mother liquor circulation pump 4.9 , Full flow tank 4.10, crystallization pump 4.11, crystallization tank 4.12, centrifuge 4.13, ammonium sulfate dryer outlet 4.14, ammonium sulfate mother liquor tank 4.15, small mother liquor pump 4.16.
  • the wastewater obtained after separation of ammonium sulfate by the centrifuge 4.13 is returned to the spray saturator 4.6 for circulating concentration and crystallization or returned to the mercury sulfide precipitation tank 5.5 to participate in the precipitation reaction.
  • the ammonium sulfate recovery liquid comes from the supernatant ((NH 4 ) 2 SO 4 +NaS) 4.1 of the precipitation tank of the mercury sulfide recovery system, and the mercury sulfate recovery liquid comes from the circulating absorption liquid outlet of the primary dynamic wave absorption reactor 1.14 (1.14-1.22-5.3), the precipitation agent of the mercury sulfide recovery system is sodium sulfide.
  • the mercury sulfide precipitates in the sedimentation tank and is separated from the ammonium sulfate and then enters the mercury sulfide dryer for recovery.
  • the waste water of the waste water recycling and treatment (zero discharge) system comes from a mercury sulfide recovery system and an ammonium sulfate recovery system, and the waste water from the mercury sulfide recovery system is derived from the precipitation and separation of mercury sulfide and contains ammonium sulfate, sodium sulfate and Excess sodium sulfide wastewater, this part of wastewater directly enters the ammonium sulfate recovery system or returns to the mercury sulfide precipitation tank. Realize zero emissions in the true sense.
  • the wastewater from the ammonium sulfate recovery system is wastewater containing sodium sulfate and sodium sulfide obtained after the ammonium sulfate crystallization tank separates ammonium sulfate crystallization, and this part of the wastewater directly enters the inlet of the secondary power wave washing liquid circulation pump.
  • NO x is composed of NO, N0 2 , N 2 0 4 , and N 2 0 3 , and other components, and the following reactions occur in the gas phase:
  • Step 1 NO X is absorbed into the liquid phase
  • the second step the rapid oxidation reaction of peroxybicarbonate radicals that are difficult to dissolve in water
  • the fourth step the nitrogen oxide absorbed into the liquid phase reacts with urea
  • the first step SO 2 dissolves in water and reacts quickly with peroxy bicarbonate radicals
  • the third step chemical absorption:
  • the first-stage kinetic wave absorption reactor obtains an absorption solution containing ammonium sulfate and HgSO 4.
  • the absorption solution containing ammonium sulfate and HgSO 4 is added with Na 2 S with a molar ratio of 1.3:1 to Hg 2+ in the absorption solution to produce
  • the mercury sulfide precipitate is separated from the mother liquor.
  • the mother liquor containing ammonium sulfate is transported to the ammonium sulfate recovery system, where ammonium sulfate is recovered through concentration and crystallization.
  • the reacted absorption liquid is pumped into the filter, and the filtered HgS is discharged. After the filtered absorption liquid is dried and crystallized, ammonium sulfate can be recovered as a high-quality fertilizer.
  • the mercury sulfide obtained by centrifugal separation can be made into high value-added semiconductor mercury sulfide.
  • the wastewater containing Na 2 SO 4 (the same molar concentration as the mercury in the absorption liquid) and excess Na 2 S is transported to the secondary dynamic wave fine purifier for recycling (4.3-6.1-6.2-3.6-3.8-3.9).
  • the concentration of the percarbonamide in the absorption solution is 80 mg/L;
  • the pH of the weakly alkaline absorption solution containing multiple strong oxidizing free radicals is controlled at 7.6 ⁇ 0.2;
  • the flow velocity of the flue gas in the throat of the power wave scrubber is 25 m/s-30 m/s;
  • the liquid-gas ratio of the power wave scrubber is 0.5 L/m 3 -0.8 L/m 3 .

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Abstract

一种烟气脱硫、脱氮、脱汞净化方法和设备。方法包含：来自烟气的二氧化碳从气相溶解于水中进行碳酸化反应，两相平衡体系的碳酸氢根(HCO 3 -)催化过碳酰胺CO(NH 2) 2H 2O 2，在水溶液中分解生成含强氧化自由基的弱碱性吸收液，快速对烟气脱硫、脱硝和脱汞。还公开了一种实现烟气脱硫、脱氮、脱汞净化方法的设备。

Description

烟气脱硫、脱氮、脱汞净化方法和设备 技术领域
本发明涉及烟气净化技术，尤其涉及一种烟气脱硫、脱氮、脱汞净化方法和设备。
背景技术
在世界范围内，大多数发展中国家仍是以煤炭为主要能源，我国便是其中之一，煤炭占我国一次能源生产和消耗比例一直在70％以上，所得的代价是其废气中的硫、氮氧化物及汞等重金属元素严重污染空气和环境。酸雨,臭氧层破坏及汞向大气层扩散,不但降低了我们的生活品质,而且危害了人体健康及地球上其他生物的生存。从根本上治理烟气中SO 2、NO X及汞的排放已经势在必行。
国、内外现有烟气净化技术中除尘、脱硫、脱硝和脱汞往往是在多个独立系统中分别完成,极少有同时一体化处理的技术.这种叠加式处理方法不仅占地面积大,系统复杂,而且设备投资与运行费用很高.
例如：目前燃煤锅炉对于SO 2的控制大量采用湿法烟气脱硫装置，效率可达95％以上；对于NO X的控制，常规控制方法有：选择性非催化SNCR和选择性催化SCR技术。SNCR技术是低成本高效率的低NO X控制技术，但脱除效率一般仅能达到50％-65％。因此，为了达到环保排放的要求，即除去烟气中的SO 2、NO X、粉尘和汞，燃煤锅炉至少需要配备两套以上独立的脱硫、脱硝系统，同时还需要增设专门的除尘、除汞设备，这样一来，整套设备系统庞大、复杂、能效低，并且占地面积大、投资高、运行成本也很高，不便于使用。
SCR是目前商业技术中最有效的低NO X控制技术，可以达到80％以上的脱氮效率，但其初期投资在490-1250/kw，非常昂贵，运行费用大约为2100～2800元/吨NO X，若在湿法脱硫的基础上再引进SCR技术，势必增加巨额的投资与运行费用，得不偿失。
同时脱除S0 2、NO x和汞的一体化工艺具有设备简单、管理操作方便、占地面积小、投资运行费用低等优点，因此烟气联合脱硫脱硝除汞技术成为当前大气污染控制的重要研究方向。其中尿素法具有以下优点：最终产物为N 2、C0 2、硫酸铵，产物可直接排放，硫酸铵可制成化肥，回收利用氮、硫资源，因此该法具有一定的研究价值。目前的技术现状是：该方法能达到很高的脱硫效率，但脱氮效率不理想，仅适用于处理纯氮氧化物废气，实际烟气中NO x的氧化度很低，NO含量占NO x的90～95％，尿素法直接应用于烟气净化较难达到很高的脱氮效率。因此人们追求在尿素溶液中加入各种化学添加剂来达到提高脱氮效率的目的，但是研究发现廉价的添加剂对脱硝效率的提高不大，而只有加入价格高的添加剂才能达到较好脱硝效率，因此增加了尿素法的操作费用，而且由于加入的添加剂组分复杂，会增加添加剂的制造成本和脱硫、脱硝废水的处理难度。
发明专利(01130154.6)尿素添加剂湿法烟气同时脱硫脱氮方法，公开了一种湿法烟气同时脱硫脱氮方法，该发明以尿素作吸收剂，加入一定量有机胺类或磷酸盐类添加剂，尿素的含量为5～30％，有机胺类添加剂采用乙二胺或三乙醇胺；磷酸盐类添加剂采用磷酸铵(或钠)或磷酸氢二铵(或钠)，浓度为(50～500)×10-4％。实现SO 2的去除率为95％以上，NO x的去除率为80％以上。有机胺类添加剂(乙二胺或三乙醇胺)是一种强腐蚀性、强刺激性性有毒化学品，该品蒸气对粘膜和皮肤有强烈刺激性。接触该品蒸气引起结膜炎、支气管炎、肺炎或肺水肿，并可发生接触性皮炎。可引起肝、肾损害。皮肤和眼直接接触其液体可致灼伤。该品可引起职业性哮喘，并且对环境有危害，对水体可造成污染。所以，大规模工业应用乙二胺是不可接受的，难以实现工业应用。
发明专利200910262978.4燃煤烟气的尿素湿法联合脱硫脱硝方法，公开了一种湿法烟气同时脱硫脱硝方法，包括以下步骤：在吸收塔(喷淋塔)燃煤烟气入口处喷入质量百分比浓度50％双氧水，保持H 2O 2/NO摩尔比＝2～3，将燃煤烟气中的NO氧化成NO 2，提高NO X的氧化度，最佳方案是将NO X的氧化度提高到50％～60％(为NO X中的NO 2与NO X的体积百分比)，再利用吸收塔中的尿素水溶液(吸收液)进行同时脱硫脱硝。由于采用高浓度的(50％)双氧水，其运输、储存存在一定的风险，而且脱硝效率只能达到50％左右。不能满足燃煤电厂执行超净排放或近零排放要求：SO 2＜35mg/Nm 3，氮氧化物:50mg/Nm 3；烟尘＜5mg/Nm 3。
发明专利201510681266.1公开了一种脱除燃煤烟气中元素汞的方法，该方法汞的脱除在湿法烟气脱硫喷淋吸收塔中进行，将制备的吸收剂自喷淋吸收塔上部喷下，对由喷淋吸收塔下部烟口引入的燃煤烟气进行喷淋，使燃煤烟气中元素态的汞与吸收剂充分反应，实现元素态汞向二价态汞的转化；所述吸收剂包括氧化性添加剂和磁性催化剂，氧化性添加剂与磁性催化剂的质量比为2～5:1，所述氧化性添加剂为过一硫酸氢钾复合盐、过硫酸钠、过硼酸钠、过碳酸钠的一种或者多种组合，所述催化剂为铁酸铋、钴掺杂铁酸铋、钴/镧掺杂铁酸铋、钴/锶掺杂铁酸铋、钴/铷掺杂铁酸铋中的一种或几种混合物。由于所用氧化性添加剂和磁性催化剂配制复杂，难以实现工业应用。
发明专利201810191344.3公开了一种基于电极催化氧化剂的湿法烟气氧化脱硫脱硝脱汞工艺，该方法采用过硫酸钾或过硫酸钠作为湿法氧化的强氧化剂，电化学反应槽中的阳极板和阴极板为以金属钛为基体材料的镀层复合材料电极板，工艺复杂，运行成本高难以实现工业规模的应用。
由此可见，采用独立的脱硫和脱氮系统实现烟气净化，不仅烟气净化设备复杂、占地面积大、建设和运行费用高，而且要将这些独立的脱硫、脱氮和除尘、除汞系统合理的组合起来实现高效运行也存在着许多困难。所以研究一体化的高效的脱硫、脱氮、脱汞一体化净化方法和高效净化设备就显得尤为重要。
发明内容
有鉴于此，本发明要解决的技术问题是提供一种烟气脱硫、脱氮、脱汞净化方法和设备,以解决现有烟气净化技术中存在的工艺复杂，运行成本高难以实现工业规模的问题。
本发明解决上述技术问题，提出一种烟气脱硫、脱氮、脱汞净化方法，包括以下步骤：
来自烟气的二氧化碳从气相溶解于水中进行碳酸化反应，并建立CO 2-H 2CO 3-HCO 3-体系的气/液两相平衡；
CO 2+H 2O→H 2CO 3    (1)
H 2CO 3→H ++HCO 3 -    (2)
HCO 3 -+H 2O 2→HCO 4 -+H 2O   (3)
所述两相平衡体系的碳酸氢根(HCO 3 -)催化过碳酰胺CO(NH 2) 2H 2O 2，
CO(NH 2) 2H 2O 2→CO(NH 2) 2+H 2O 2    (4)
CO 2+H 2O 2+→H 2CO 4   (5)
H 2CO 4→HCO 4 -+H +    (6)
在水溶液中分解生成含强氧化自由基的弱碱性吸收液，快速对烟气脱硫、脱硝和脱汞。
进一步的，所述含强氧化自由基的弱碱性吸收液为由过氧碳酸氢根离子、羟基自由基、碳酸根阴离子自由基、氢过氧自由基、超氧阴离子自由基、尿素、过氧化氢和碳酸氢根的一种或多种组成的pH值为7～9的均相混合溶液。
进一步的，所述pH值为7.6±0.2。
本发明还提出一种烟气脱硫、脱氮、脱汞净化设备,包括：一级动力波吸收反应器、二氧化碳催化反应器、二级动力波精细净化器、硫酸铵回收系统、硫化汞回收系统和废水循环与处理系统；所述二氧化碳催化反应器设置在一级动力波吸收反应器和二级动力波精细净化器之间；所述二氧化碳催化反应器，用于生产、储存和输送含强氧化自由基的弱碱性吸收液。
进一步的，所述一级动力波吸收反应器包括一个双层动力波吸收塔、顺流静态混合器、循环吸收液存储罐和含强氧化自由基的弱碱性吸收液的循环输送系统。
进一步的，所述双层动力波吸收塔内部设置有上下两层独立布置的两个喷嘴；所述两个喷嘴的上方空间在运行中形成两个吸收泡沫层。
进一步的，所述循环吸收液存储罐下方的循环吸收液出口通过循环水管和吸收液循环泵与双层动力波吸收塔的第二喷嘴的进水口连通。
进一步的，所述来自二氧化碳催化反应器的含强氧化自由基的弱碱性吸收液输送泵的出口与双层动力波吸收塔的第一喷嘴的进水口连通；所述循环吸收液存储罐与静态混合器连通。
进一步的，所述的一级动力波吸收反应器还包括一个顺流静态混合器，所 述顺流静态混合器的入口与双层动力波吸收塔的底部连通；所述顺流静态混合器通过连通管和连接管与集液槽连接，连通管与集液槽的下部连接，连接管与集液槽的上部连接，所述连通管内部流动的是液相吸收液；所述连接管的内部流动的是气液混合相。
进一步的，所述双层动力波吸收塔内部设置有上下两层独立布置的两个喷嘴。
本发明实现的烟气脱硫、脱硝、脱汞一体化净化方法和设备，通过烟气中的二氧化碳(CO2)催化过碳酰胺生成一种无反应选择性的富氧活化自由基-过氧碳酸氢根自由基(HCO4-)，对燃煤锅炉的烟气进行同时脱硫、脱硝和脱汞的一体化方法和设备，具有能效高、运行稳定、投资少、运行成本低、适用性强、并能实现“零排放”无二次污染和副产物资源化等优点。。
附图说明
图1为本发明实施例提供的烟气脱硫、脱硝、脱汞一体化净化工艺流程图。
图2是硫酸铵回收系统工艺流程图。
图中各标号如下：
1一级动力波吸收反应器:
1.0洗涤吸收管，
1.1烟气入口，
1.2第一喷嘴，
1.3第一吸收泡沫层，
1.4第二吸收泡沫层，
1.5第二喷嘴，
1.6吸收液循环泵，
1.7静态混合器，
1.8排污出口，
1.9两相联通管，
1.10气液分离区，
1.11吸收液存储罐，
1.12液膜分离器，
1.13烟气出口，
1.14循环吸收液出口，
1.15吸收液连接管，
1.16吸收液输送管，
1.17-1.19吸收液控制阀，
1.20吸收液循环管，
1.21吸收液循环控制阀，
1.22吸收液回收控制阀，
2.二氧化碳催化反应器:
2.0二氧化碳催化反应器吸收液存储罐，
2.1碳酸氢铵给料装置，
2.2过碳酰胺给料装置，
2.3搅拌器，
2.4pH调节控制系统，
2.5pH传感器，
2.6烟气(CO 2)入口，
2.7烟气(CO 2)出口，
2.8吸收液控制阀，
2.9一级动力波吸收反应器吸收液输送泵，
2.10一级动力波吸收反应器吸收液调节阀，
2.11二级动力波精细净化器吸收液调节阀，
2.12二级动力波精细净化器吸收液输送泵，
2.13高位除盐水箱，
2.14高位除盐水箱除盐水入口控制阀，
2.15除盐水泵，
2.16除盐水泵进口控制阀，
2.17高位除盐水箱除盐水出口，
2.18二氧化碳催化反应器除盐水入口，
2.19烟气循环风机，
2.20二级动力波精细净化器烟气旁路出口。
3二级动力波精细净化器：
3.0二级动力波精细净化器吸收塔，
3.1二级动力波精细净化器烟气入口，
3.2烟气分配网，
3.3二级动力波精细净化器洗涤液存储罐，
3.4二级动力波洗涤液排污口
3.5洗涤液循环泵入口控制阀，
3.6洗涤液循环泵，
3.7洗涤液控制阀，
3.8洗涤液入口，
3.9洗涤液喷嘴，
3.10洗涤泡沫层，
3.11烟气分配网，
3.12烟气出口扩散锥，
3.13除沫器，
3.14净化烟气出口(通往烟囱)。
4.硫酸铵回收系统
4.1硫化汞回收系统沉淀池排水，
4.2硫酸铵结晶输出，
4.3硫酸铵回收系统废水循排放口，
4.4硫酸高位槽，
4.5硫酸补充管路，
4.6喷淋式饱和器，
4.7加热烟气人口，
4.8加热烟气出口，
4.9硫酸铵母液循环泵，
4.10满流槽，
4.11结晶泵，
4.12结晶槽，
4.13离心机，
4.14去硫酸铵干燥机，
4.15硫酸铵母液槽，
4.16小母液泵。
5硫化汞回收系统：
5.1 HgS沉淀池，
5.2 NaS进料口，
5.3硫酸铵硫酸汞混合液入口，
5.4 HgS浆液出口(接HgS过滤器)。
6.废水循环与处理(零排放)系统
6.1硫酸铵回收系统废水循环泵，
6.2硫酸铵回收系统废水循环控制阀，
6.3硫酸铵回收系统废水循环控制阀。
具体实施方式
下面将对本发明实施例中的技术方案进行清楚、完整的描述，显然，所描述的实施例仅是本发明的一部分实施例，而不是全部的实施例。基于本发明中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其它实施例，都属于本发明保护的范围。
本发明一个方面提供一种烟气脱硫、脱硝、脱汞一体化高效净化方法，通过二氧化碳催化过碳酰胺生成一种含有多种强氧化自由基的弱碱性吸收液，实现快速吸收烟气中的SO 2、NO x，同时将元素汞Hg 0氧化成易被吸收的二价汞Hg 2+的化学反应。
所述含强氧化自由基的弱碱性吸收液是由过氧碳酸氢根离子(HCO 4 -)、羟基自由基(OH· -)、碳酸根阴离子自由基(CO 3· -)、氢过氧自由基(HO 2· -)、超氧阴离子自由基(O 2· -)、尿素、过氧化氢和碳酸氢根(HCO 3 -)等组成的pH值为7～9的弱碱性均相混合溶液；
所述二氧化碳催化过碳酰胺的催化剂为来自烟气的二氧化碳，所述二氧化碳以气相溶解于水中完成碳酸化反应并在合适的pH条件下建立CO 2-H 2CO 3-HCO3 -体系气液两相平衡，所述两相平衡体系的碳酸氢根(HCO 3 -)催化过碳酰胺在水溶液中分解生成的过氧化氢并生成强氧化活性基团过氧碳酸氢根离子(HCO 4 -)。
CO 2+H 2O→H 2CO 3   (1)
H 2CO 3→H ++HCO 3 -    (2)
HCO 3 -+H 2O 2→HCO 4 -+H 2O   (3)
所述二氧化碳催化过碳酰胺的反应过程是：在二氧化碳催化作用下首先生成过氧碳酸氢根离子(HCO 4 -)，过氧碳酸氢根离子进一步分解成羟基自由基(OH· -)和碳酸根阴离子自由基(CO 3· -)，后者进一步和过氧化氢作用，生成氢过氧自由基(HO 2· -)，而氢过氧自由基又可以分解为超氧阴离子自由基(O 2· -)。这些活性自由基可以快速实现烟气脱硫、脱硝和脱汞。
所述过氧碳酸氢根自由基，是一种具有极强氧化性且无反应选择性的富氧活化自由基，这种活化自由基的特征是：其反应活性是过氧化氢的100倍以上。反应的pH值为7～9的中性或弱碱性的弱腐蚀性条件。
所述过氧碳酸氢根自由基是由烟气中的二氧化碳(CO 2)催化过碳酰胺按反应方程式(4)、(5)、(6)所生成的反应产物，这个反应在质子性溶剂和非质子性 溶剂中都非常容易发生。
CO(NH 2) 2H 2O 2→CO(NH 2) 2+H 2O 2   (4)
CO 2+H 2O 2+→H 2CO 4    (5)
H 2CO 4→HCO 4 -+H +    (6)
所述过氧化氢是由过碳酰胺CO(NH 2) 2H 2O 2(过氧化尿素)在水溶液中分解生成的产物(4)；
所述过碳酰胺是尿素与过氧化氢直接以氢键相联接所形成的加和物，是一种新型固体过氧化氢(H 2O 2含量≧35％)稳定载体。过碳酰胺的理论活性氧含量为16.0％，H 2O 2含量35.0％；分子式是CO(NH 2) 2H 2O 2。
实施例1：
本实施例陈述的一种基于过氧碳酸氢根自由基的烟气脱硫、脱硝、脱汞一体化高效净化方法的是通过一个两级动力波吸收净化系统来实现的。所述两级动力波吸收净化系统包括：一级动力波吸收反应器、二氧化碳催化反应器、二级动力波精细净化器、硫酸铵回收设备、硫化汞回收设备和废水处理循环系统。
所述一级动力波吸收反应器，其结构如图1所示，包括：1.0洗涤吸收管，1.1烟气入口，1.2第一喷嘴，1.3第一吸收泡沫层，1.4第二吸收泡沫层，1.5第二喷嘴，1.6吸收液循环泵，1.7静态混合器，1.8排污出口，1.9两相联通管，1.10惯性分离室(气液分离区)，1.11吸收液存储罐，1.12液膜分离器，1.13烟气出口，1.14循环吸收液出口，1.15吸收液连接管，1.16吸收液输送管，1.17-1.19吸收液控制阀，1.20吸收液循环管，1.21吸收液循环控制阀，1.22吸收液回收控制阀等组成。
所述洗涤吸收管1.0为垂直安装，顶部为气体进口1.1，下部设置循环吸收液输送管1.16，循环吸收液输送管1.16连接到第二喷嘴1.5的入口(1.17-1.18)和第一喷嘴1.2的入口(1.19)。
所述喷嘴1.2和1.5)采用大孔径非节流型的开孔喷射喷嘴。所述开孔喷射的特征是喷射出的液体不发生雾化，排气中液体雾沫的数量极少，使用常规的气液分离器即可脱除残余液体。
在喷嘴1.5的上方有气液两相逆向高速撞击形成的第二吸收泡沫区1.4。洗涤吸收管1经静态混合器1.7与惯性分离室1.10连接。混合器1.7位于第二喷嘴1.5的下方，它使顺流流动的气液两相，再一次进行湍流混合，起到了顺流洗涤的作用。静态混合器1.7与集液槽1.11之间通过连通管1.9和连接管1.15相连接，连通管1.15与集液槽1.11的下部连接，连接管1.9与集液槽1.11的上部连接，连通管1.15内流动的是液相吸收液，连接管1.9内流动的是气液混合相(烟气+吸收液)。集液槽1.11的顶部为净化烟气出口1.13，上部设有切 向进口与连接管1.9相连接，底部设有循环洗涤液出口1.12，在集液槽1.11上部为气液离心分离区1.10，下部为集液区。
待净化的烟气由烟气入口1.1自上而下高速进入洗涤管1.0，洗涤吸收液通过循环水泵由特殊结构的第一喷嘴1.2自下而上喷入气流中，造成气、液两相高速逆向对撞，当气液两相的动量达到平衡时，形成一个高度湍动的泡沫区1.3，在泡沫区1.3，气、液两相呈高速湍流接触，接触表面积大，而且这些接触表面不断地得到迅速更新，达到高效泡沫洗涤、吸收效果。然后气、液两相顺流流动，经过静态混合元件1.7，使气液两相再一次进行湍流混合，起到了顺流洗涤的作用，实现了两级串联的洗涤吸收效果。净化后的气体在静态混合元件1.7的惯性分离区首次与洗涤吸收液进行分离，绝大部分洗涤吸收液因惯性被分离下来后由连通管1.15进入集液槽1.11下部的集液区，而夹带液沫的气体则由连接管1.9以切线方向进入集液槽1.11上部的离心分离区，所夹带的液沫在离心力的作用下被甩向壁面，并沿壁面下落进入集液槽1.11下部的集液区，气液两相再一次得到分离，经过两级洗涤和两级分离而彻底净化后的烟气由烟气出口1.13排出。
本实施例提供的设备，动力波洗涤器、动力波循环泵、气液分离塔、吸收循环泵、喷淋器、旋流除雾器和湿式静电除尘器均为现有技术中本技术领域内的常规技术产品。
实施例2
本实施例中，一级动力波吸收反应器入口烟气中的SO 2﹑NO x与Hg0浓度分别为2000ppm，400ppm以及50μg/Nm 3，烟尘浓度：12g/Nm 3,，烟气入口温度为100℃。液气比为0.6L/Nm 3，过碳酰胺在吸收液中的浓度为50mg/L，溶液pH为7.6，溶液温度为70℃，小试结果为：一级动力波吸收反应器出口烟气中SO 2﹑NO x、Hg0与粉尘的同时脱除效率可分别达到99.2％，98.5％，95％和99.9％。
实施例3
本实施例中，一级动力波吸收反应器入口烟气中的SO 2﹑NO x与Hg0浓度分别为2000ppm，400ppm以及50μg/Nm 3，烟尘浓度：12g/Nm 3,，温度为100℃。液气比为0.8L/Nm 3，过碳酰胺在吸收液中的浓度为50mg/L，溶液pH为7.6，溶液温度为70℃，小试结果为：一级动力波吸收反应器出口烟气中SO 2﹑NO x、Hg0与粉尘的同时脱除效率可分别达到100％，100％，96％和99.9％。
实施例4
本实施例中，一级动力波吸收反应器入口烟气中的SO 2﹑NO x与Hg0浓度分别为2000ppm，400ppm以及50μg/Nm 3，烟尘浓度：12g/Nm 3,，烟气温度为100℃。 液气比为0.8L/Nm 3，过碳酰胺在吸收液中的浓度为60mg/L，溶液pH为7.2，溶液温度为70℃，小试结果为：一级动力波吸收反应器出口烟气中SO 2﹑NO x、Hg0与粉尘的同时脱除效率可分别达到100％，100％和100％，100％。
实施例5
本实施例中，一级动力波吸收反应器入口烟气中的SO 2﹑NO x与Hg0浓度分别为2000ppm，400ppm以及50μg/m 3，烟尘浓度：12g/Nm 3,，烟气温度为100℃。液气比为0.9L/Nm 3，过碳酰胺在吸收液中的浓度为80mg/L，溶液pH为7.5，溶液温度为70℃，小试结果为：一级动力波吸收反应器出口烟气中SO 2﹑NO x、Hg0与粉尘的同时脱除效率可分别达到100％，100％、100％和100％。
实施例6
本实施例中，一级动力波吸收反应器入口烟气中的SO 2﹑NO x与Hg0浓度分别为2000ppm，400ppm以及50μg/m 3，烟尘浓度：12g/Nm 3,，烟气温度为100℃。液气比为1.0L/Nm 3，过碳酰胺在吸收液中的浓度为100mg/L，溶液pH为7.6，溶液温度为70℃，小试结果为：一级动力波吸收反应器出口烟气中SO 2﹑NO x、Hg0与粉尘的同时脱除效率可分别达到100％，100％、100％和99％。
实施例7
本实施例中，一级动力波吸收反应器入口烟气中的SO 2﹑NO x与Hg0浓度分别为2000ppm，400ppm以及50μg/Nm 3，烟尘浓度：12g/Nm 3,，烟气温度为100℃。液气比为0.6L/m 3，过碳酰胺在吸收液中的浓度为60mg/L，溶液pH为7.8，溶液温度为70℃，小试结果为：一级动力波吸收反应器出口烟气中SO 2﹑NO x、Hg0与粉尘的同时脱除效率可分别达到100％，100％、100％和100％。
实施例8
本实施例中，一级动力波吸收反应器入口烟气中的SO 2﹑NO x与Hg0浓度分别为2000ppm，400ppm和50μg/Nm 3，，烟尘浓度：12g/Nm 3,，烟气口温度为100℃。液气比为0.6L/m 3，过碳酰胺在吸收液中的浓度为60mg/L，溶液pH为7.6，溶液温度为70℃，小试结果为：一级动力波吸收反应器出口烟气中SO 2﹑NO x、Hg0与粉尘的同时脱除效率可分别达到100％，100％、100％和100％。
实施例9
本实施例中，(600MW燃煤机组)：烟气流量1900000Nm 3/h,一级动力波吸收反应器入口烟气中的SO 2﹑NO x与Hg0浓度分别为1700mg/Nm3，500mg/Nm3以及30μg/Nm 3，烟尘浓度：11g/Nm 3,，烟气温度为100℃。液气比为0.6L/Nm 3，过碳酰胺在吸收液中的浓度为80mg/L，溶液pH为7.6，吸收液温度为70℃，小试结果为：一级动力波吸收反应器出口烟气中SO 2﹑NO x、Hg0与粉尘的同时脱除效率可分别达到100％，100％，100％和99.9％。表1是600MW燃煤机组的设计数据。
表1 600MW燃煤机组一体化脱硫脱硝脱汞动力波吸收塔设计参数
Figure PCTCN2020094783-appb-000001
实施例10
本实施例中，(300MW燃煤机组)：烟气流量1050000Nm 3,一级动力波吸收反应器入口烟气中的SO 2﹑NO x与Hg0浓度分别为6500mg/Nm3，500mg/Nm3以及20μg/Nm 3，烟尘浓度：40g/Nm 3,，烟气温度为100℃。液气比为0.6L/Nm 3，过碳酰胺在吸收液中的浓度为80mg/L，溶液pH为7.6，吸收液温度为70℃，小试结果为：一级动力波吸收反应器出口烟气中SO 2﹑NO x、Hg0与粉尘的同时脱除效 率可分别达到100％，100％，100％和99.9％。表2是300MW燃煤机组的设计数据。
表2 300MW燃煤机组一体化脱硫脱硝脱汞动力波吸收塔设计参数
Figure PCTCN2020094783-appb-000002
经过以上实施例的综合对比可知，实施例4、5、7和8具有最佳脱除效果，SO 2，NO x、Hg0与粉尘的脱除效率均达到100％，可作为最佳实施例参照使用。
优选的，所述过碳酰胺在吸收液中的浓度为80mg/L；
优选的，所述含有多种强氧化自由基的弱碱性吸收液的pH控制在7.6；
优选的，所述动力波洗涤器喉管内烟气流速为25米/秒；
优选的，所述动力波洗涤器的液气比为0.6L/m 3，即：1标准立方米烟气需 要0.6升的循环吸收液。
本发明第二个方面提供一种烟气脱硫、脱硝、脱汞一体化高效净化的设备如图1所示，包括：一级动力波吸收反应器、二氧化碳催化反应器、二级动力波精细净化器、硫酸铵回收系统、硫化汞回收系统和废水循环与处理(零排放)系统。在一级动力波吸收反应器和二级动力波精细净化器之间设置有二氧化碳催化反应器，所述二氧化碳催化反应器是含强氧化自由基的弱碱性吸收液的生产、储存和输送系统；所述一级动力波吸收反应器包括一个双层动力波吸收塔1.0、顺流静态混合器1.7和循环吸收液存储罐1.11。
所述双层动力波吸收塔1.0垂直固定安装在所述静态混合器1.7的顶部；所述双层动力波吸收塔1.0底部与静态混合器1.7的入口连通，其顶部为烟气进口1.1；所述静态混合器1.7通过吸收液连接管1.15、两相联通管1.9和吸收液存储罐1.11连接；
所述双层动力波吸收塔1.0内部设置有上下两层布置的喷嘴1.2和喷嘴1.5；所述两个喷嘴的上方空间在运行中形成两个吸收泡沫层，如图1所示，分别为吸收泡沫层1.3和吸收泡沫层1.4；所述循环吸收液出口通过循环水管1.20和吸收液循环泵1.6与双层动力波吸收塔的第2(下层)喷嘴1.5的进水口1.18连通；所述来自二氧化碳催化反应器的含强氧化自由基的弱碱性吸收液输送泵2.9的出口2.10与双层动力波吸收塔的第1(上层)喷嘴1.2的进水口1.19连通；所述循环吸收液存储罐1.11与静态混合器1.7连通，所述吸收液存储罐的底部开设有循环吸收液出口1.14；所述循环吸收液存储罐的顶部固定安装有液膜分离器1.12；所述液膜分离器出口连接烟气出口1.13，所述烟气出口和二级动力波精细净化器的烟气入口3.1连接。
所述吸收泡沫层1.3和吸收泡沫层1.4，在泡沫层内,气液两相接触面积极大,且不断更新,从而可获得极高的传热与传质效率。
所述二氧化碳催化反应器2包括：烟气(二氧化碳)入口管道2.6、烟气出口管道2.7、吸收液存储灌2.0、(pH调节剂)碳酸氢铵给料装置2.1、过碳酰胺给料装置2.2、搅拌器2.3、吸收液pH调节控制系统2.4、一级动力波吸收反应器吸收液输送泵2.9、二级动力波精细净化器吸收液输送泵2.12、一级动力波吸收反应器吸收液调节阀2.10和二级动力波精细净化器吸收液调节阀2.11、吸收液控制阀2.8、除盐水控制阀2.16和除盐水泵2.15；所述除盐水泵2.15入口连接到除盐水箱(图中未画出)；除盐水泵2.15出口连接到高位除盐水箱2.13的除盐水入口控制阀2.14的入口；高位除盐水箱2.13的除盐水出口2.17连接到二氧化碳催化反应器吸收液存储罐2.0的除盐水入口2.18。
所述过碳酰胺供给设备包括：过碳酰胺存储仓、螺旋自动加料机、吸收液存储灌；
所述碳酸氢铵供给设备包括：碳酸氢铵存储仓、螺旋自动加料机、吸收液存储灌和pH调节控制系统2.4。所述烟气入口管道2.6连接到烟气循环风机2.19的出口，所述烟气循环风机的入口连接到二级动力波精细净化器烟气旁路出口2.20，所述烟气出口管道2.7接到二级动力波精细净化器的烟气入口3.1。
所述二级动力波精细净化器包括：二级动力波精细净化器吸收塔3.0、烟气入口3.1、烟气分配网3.2、二级动力波精细净化器洗涤液存储罐3.3、二级动力波洗涤液排污口3.4、洗涤液循环泵入口控制阀3.5、洗涤液循环泵3.6、洗涤液控制阀3.7、洗涤液入口3.8、洗涤液喷嘴3.9、洗涤泡沫层3.10、烟气分配网3.11、烟气出口扩散锥3.12、除沫器3.13、净化烟气出口(通往烟囱)3.14。
所述二级动力波精细净化器的特征是：烟气的流动方向是自下而上，洗涤液自上而下逆向喷射；所述二级动力波精细净化器的洗涤液是来自二氧化碳催化反应器的含强氧化自由基的弱碱性吸收液(2.12-3.7-3.8-3.9)或来自废水循环与处理(零排放)系统的废水(6.1-6.2-3.6)。
所述硫酸铵回收系统如图2所示，包括：硫酸高位槽4.4，硫酸补充管路4.5，喷淋式饱和器4.6，加热烟气人口4.7，加热烟气出口4.8，硫酸铵母液循环泵4.9，满流槽4.10，结晶泵4.11，结晶槽4.12，离心机4.13，去硫酸铵干燥机出口4.14，硫酸铵母液槽4.15，小母液泵4.16。所述离心机4.13分离硫酸铵后得到的废水返回喷淋式饱和器4.6循环浓缩结晶或回流到硫化汞沉淀池5.5参与沉淀反应。所述硫酸铵回收液来自硫化汞回收系统沉淀池的上清液((NH 4) 2SO 4+NaS)4.1,所述硫酸汞回收液，来自一级动力波吸收反应器的循环吸收液出口1.14(1.14-1.22-5.3)，所述硫化汞回收系统的沉淀剂是硫化钠。硫化汞沉淀在沉淀池与硫酸铵分离后进入硫化汞干燥器回收。
所述废水循环与处理(零排放)系统的所述废水来自硫化汞回收系统和硫酸铵回收系统，所述来自硫化汞回收系统的废水是来自硫化汞沉淀分离得到的含有硫酸铵、硫酸钠和过剩硫化钠的废水，这部分废水直接进入硫酸铵回收系统或返回硫化汞沉淀池。实现真正意义上的零排放。
所述水来自硫酸铵回收系统的废水是来自硫酸铵结晶槽分离硫酸铵结晶后得到的含有硫酸钠和硫化钠的废水，这部分废水直接进入二级动力波洗涤液循环泵入口。
主要化学反应如下：
(1)生成过氧碳酸氢根自由基的反应
CO 2+H 2O→H 2CO 3    (1)
H 2CO 3→H ++HCO 3 -    (2)
HCO 3 -+H 2O 2→HCO 4 -+H 2O   (3)
(1)+(2)+(3)→(5)
CO(NH 2) 2H 2O 2→CO(NH 2) 2+H 2O 2   (4)
CO 2+H 2O 2+→H 2CO 4   (5)
H 2CO 4→HCO 4 -+H +    (6)
(2)过氧碳酸氢根自由基的快速氧化(脱硫、脱氮、脱汞)反应
HCO 4 -+SO 2→HCO 3 -+SO 3    (7)
HCO 4 -+NO→HCO 3 -+NO 2    (8)
2HCO 4 -+Hg 0→2HCO 3 -+Hg 2+    (9)
HCO 3 -+H +→H 2CO 3    (10)
H 2CO 3→CO 2+H 2O    (11)
Hg 2++SO 4 2-→HgSO 4    (12)
从反应式(7)-(11)可以看出：过氧碳酸氢根自由基反应后又变回二氧化碳，即是说，在生成过氧碳酸氢根自由基引发的脱硫、脱氮、脱汞过程中，二氧化碳是一种催化剂。在脱硫、脱氮、脱汞过程中并不消耗二氧化碳。这种通过催化反应生成自由基的中间反应却极大地提高了脱硫、脱硝、脱汞的反应速度，降低了脱硫、脱硝、脱汞反应的活化能。
(3)脱硝反应
烟气中的NOx的吸收是一个复杂的过程，因为其中包括很多化学反应。NO x由NO，N0 2，N 20 4，和N 20 3，等组分组成，在气相中发生以下反应:
2NO+O 2→2NO 2     (13)
Figure PCTCN2020094783-appb-000003
Figure PCTCN2020094783-appb-000004
第一步:：NO X被吸收至液相
NO X的不同组分都可以被吸收至液相，NO除外(NO在水中的亨利常数非常小，50℃时只有1.25×10 -3mol/L(aTm)。反应如下：
Figure PCTCN2020094783-appb-000005
Figure PCTCN2020094783-appb-000006
Figure PCTCN2020094783-appb-000007
Figure PCTCN2020094783-appb-000008
第二步:过氧碳酸氢根自由基快速氧化难溶于水的NO的反应
HCO 4 -+NO→HCO 3 -+NO 2   (8)
第四步：吸收至液相的氮氧化物与尿素反应
HNO 2+(NH 2) 2CO→2N 2+CO 2+3H 2O    (20)
总反应方程为：
NO(g)+NO 2(g)+(NH 2) 2CO(aq)→2H 2O(l)+CO 2(g)+2N 2(g)    (21)
由以上的反应机理可知，NOx的去除主要是通过难被水吸收的NO的氧化反应(8)，生成的反应产物NO 2随后溶于水溶液，与尿素发生化学反应生成N 2和C0 2的途径得到去除的。因此提高NO的氧化度就能有效地提高NOx的去除效果。
(4)脱硫反应
第一步:SO 2溶于水并与过氧碳酸氢根自由基快速氧化反应
SO 2+H 2O→H ++HSO 3 -     (22)
HSO 3 -→H ++SO 3 2-    (23)
HCO 4 -+SO 3 2-→HCO 3 -+SO 4 2-    (24)
第二步：尿素水解：
CO(NH 2) 2+H 2O→NH 2COONH 4     (25)
NH 2COONH 4+H 2O→(NH 4) 2CO 3     (26)
(NH 4) 2CO 3→2NH 3+CO 2+H 2O     (27)
第三步：化学吸收：
SO 4 2-+2NH 4 +→(NH 4) 2SO 4    (28)
脱硫总反应方程式为：
SO 2(g)+HCO 4 -+(NH 2) 2CO(aq)+2H 2O(f)→(NH 4) 2SO 4(aq)+CO 2(g)+HCO 3 -   (29)
一级动力波吸收反应器得到含硫酸铵和HgSO 4的吸收液，对含硫酸铵和HgSO 4吸收液加入与吸收液中Hg 2+的摩尔比为1.3：1的Na 2S进行反应，生成硫化汞沉淀与母液分离。含硫酸铵的母液被输送到硫酸铵回收系统，经浓缩、结晶回收硫酸铵。
HgSO 4+Na 2S→HgS↓+2Na 2SO 4   (30)
反应后的吸收液泵入过滤器，过滤出的HgS排出，过滤后的吸收液经干燥、结晶后得到可以回收优质化肥硫酸铵。离心分离得到的硫化汞可制成高附加值的半导体硫化汞。
含Na 2SO 4(和吸收液中的汞摩尔浓度相同)和过量的的Na 2S废水输送到二级动力波精细净化器循环使用(4.3-6.1-6.2-3.6-3.8-3.9)。
优选的，所述过碳酰胺在吸收液中的浓度为80mg/L；
优选的，所述含有多种强氧化自由基的弱碱性吸收液的pH控制在7.6±0.2；
优选的，所述动力波洗涤器喉管内烟气空塔流速为：25米/秒-30米/秒；
优选的，所述动力波洗涤器的液气比为0.5L/m 3-0.8L/m 3。
以上参照附图说明了本发明的优选实施例，并非因此局限本发明的权利范围。本领域技术人员不脱离本发明的范围和实质，可以有多种变型方案实现本发明，比如作为一个实施例的特征可用于另一实施例而得到又一实施例。凡在运用本发明的技术构思之内所作的任何修改、等同替换和改进，均应在本发明的权利范围之内。

Claims (10)

  1. 一种烟气脱硫、脱氮、脱汞净化方法，其特征在于包括以下步骤：
    来自烟气的二氧化碳从气相溶解于水中进行碳酸化反应，并建立CO 2-H 2CO 3-HCO 3-体系的气/液两相平衡；
    CO 2+H 2O→H 2CO 3    (1)
    H 2CO 3→H ++HCO 3 -    (2)
    HCO 3 -+H 2O 2→HCO 4 -+H 2O    (3)
    所述两相平衡体系的碳酸氢根(HCO 3 -)催化过碳酰胺CO(NH 2) 2H 2O 2，
    CO(NH 2) 2H 2O 2→CO(NH 2) 2+H 2O 2    (4)
    CO 2+H 2O 2+→H 2CO 4    (5)
    H 2CO 4→HCO 4 -+H +    (6)
    在水溶液中分解生成含强氧化自由基的弱碱性吸收液，快速对烟气脱硫、脱硝和脱汞。
  2. 根据权利要求1所述的烟气脱硫、脱氮、脱汞净化方法，其特征在于：所述含强氧化自由基的弱碱性吸收液为由过氧碳酸氢根离子、羟基自由基、碳酸根阴离子自由基、氢过氧自由基、超氧阴离子自由基、尿素、过氧化氢和碳酸氢根的一种或多种组成的pH值为7～9的均相混合溶液。
  3. 根据权利要求2所述的烟气脱硫、脱氮、脱汞净化方法，其特征在于：所述pH值为7.6±0.2。
  4. 一种烟气脱硫、脱氮、脱汞净化设备,包括：一级动力波吸收反应器、二氧化碳催化反应器、二级动力波精细净化器、硫酸铵回收系统、硫化汞回收系统和废水循环与处理系统；所述二氧化碳催化反应器设置在一级动力波吸收反应器和二级动力波精细净化器之间；所述二氧化碳催化反应器，用于生产、储存和输送含强氧化自由基的弱碱性吸收液。
  5. 根据权利要求4所述的烟气脱硫、脱氮、脱汞净化设备，其特征在于：所述一级动力波吸收反应器包括一个双层动力波吸收塔、顺流静态混合器、循环吸收液存储罐和含强氧化自由基的弱碱性吸收液的循环输送系统。
  6. 根据权利要求5所述的烟气脱硫、脱氮、脱汞净化设备，其特征在于：所述双层动力波吸收塔内部设置有上下两层独立布置的两个喷嘴；所述两个喷嘴的上方空间在运行中形成两个吸收泡沫层。
  7. 根据权利要求5所述的烟气脱硫、脱氮、脱汞净化设备，其特征在于：所述循环吸收液存储罐下方的循环吸收液出口通过循环水管和吸收液循环泵与双层动力波吸收塔的第二喷嘴的进水口连通。
  8. 根据权利要求4所述的烟气脱硫、脱氮、脱汞净化设备，其特征在于：所述来自二氧化碳催化反应器的含强氧化自由基的弱碱性吸收液输送泵的出口与双层动力波吸收塔的第一喷嘴的进水口连通；所述循环吸收液存储罐与静态混合器连通。
  9. 根据权利要求4所述的烟气脱硫、脱氮、脱汞净化设备，其特征在于：所述的一级动力波吸收反应器还包括一个顺流静态混合器，所述顺流静态混合器的入口与双层动力波吸收塔的底部连通；所述顺流静态混合器通过连通管和连接管与集液槽连接，连通管与集液槽的下部连接，连接管与集液槽的上部连接，所述连通管内部流动的是液相吸收液；所述连接管的内部流动的是气液混合相。
  10. 根据权利要求5所述的烟气脱硫、脱氮、脱汞净化设备，其特征在于：所述双层动力波吸收塔内部设置有上下两层独立布置的两个喷嘴。
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