Background technology
The pollution of acid rain and the harm caused thereof have become one of important environmental problem paid close attention to whole world various countries.China take coal as the country of main energy sources, adds up according to investigations, the SO of China more than 90%
2, more than 67% NO
x, more than 70% the discharge capacity of flue dust all come from burning of coal.And the SO that coal combustion produces
2and NO
xit is the main source that industrial waste gas pollutes (acid rain harm).Nitrogen oxide also can form photochemical pollution, produces greenhouse effects, damages the ozone layer, have the harm such as toxic action processed to human body.Nitrogen oxide and oxysulfide also can be converted into PM2.5 and cause haze weather.
The whole world mercury total amount be discharged into every year in air has more than 5000 ton, and wherein about 4000 tons is artificial result, and the mercury emission of coal-fired process accounts for more than 30%.In China's raw coal, mercury content excursion is at 0.1 ~ 5.5mg/Kg, average mercury content 0.22mg/Kg.Because the yearly consumption of China's fire coal is huge, the amount of annual coal fire discharged mercury and pollutant thereof is all very surprising, the current mercury emission of China exceedes the U.S., and growth rate is very fast, constitute grave danger to human health and ecological environment, the discharge capacity therefore controlling Mercury In Coal Combustion Flue Gas is significant.During coal combustion, mercury major part enters air with flue gas, and what enter lime-ash only accounts for fraction, wherein accounts for 23.1% ~ 26.9% in flying dust, accounts for 56.3% ~ 69.7% in flue gas, and the mercury entering lime-ash only accounts for about 2%.Therefore controlling coal-fired mercury pollution key is that the mercury controlled in flue gas discharges in air.Oxidant SO stronger in flue gas
2, NO
2, Cl
2etc. simple substance and the oxide existence form that obviously can affect mercury metal.Along with the increase of oxidant, too increase the oxide components of mercury, as HgCl
2, HgSO
4deng.
Mercury In Coal Combustion Flue Gas belongs to trace level pollutant, wherein mainly contains three kinds of forms: gaseous elemental mercury, gaseous oxidation mercury, solid granulates mercury.Wherein gaseous elemental mercury is the main existence form of mercury in flue gas.The existing forms of mercury in flue gas has removed material impact to mercury.The principal element affecting mercury in flue gas existing forms has coal-fired kind, ignition temperature, smoke components etc.Physics, the chemical property of mercury species differ greatly.As soluble in water in gaseous oxidation mercury, and easily adsorbed by the particle in flue gas, therefore easily removed by wet desulphurization equipment or cleaner, particle mercury is also easily removed by deduster, contrary atomic state mercury volatility is high, water-soluble low, is difficult to be desulfurized or cleaner is caught, and almost all discharges into the atmosphere, and mean residence time reached half a year by 2 years in an atmosphere, the conveying of logical long-distance forms mercury pollution widely very easily in an atmosphere.Atomic state mercury is form the most rambunctious, is also the difficult point of coal-fired flue gas mercury removal.
At present, what industrial employing was more is selective catalytic reduction, namely adopt ammonia or urea to make reducing agent and NO is reduced to nitrogen, as patent US Patent4,221,768, Swedish Patent8404840-4, US Patent4,101,238, US Patent4,048, the method disclosed in 112.But said method needs at relatively high temperatures (350
right) just can carry out, and also catalyst price is higher, easy poisoning and deactivation, can not realize desulphurization denitration simultaneously.Japan Patent P1659565j (1976), P181759c (1976), P63100918, A2 (1988) remove NO while proposing
xand SO
2method adopt oxidant NO is oxidized to NO soluble in water
2, as chloric acid, potassium permanganate, hydrogen peroxide, ozone etc., but liquid phase oxidation is failed popularization and is come due to high in cost of production reason.The yellow phosphorus method (see document Nature, 1990,343 (11): 151-153) that California, USA university Berkeley laboratory proposes, can remove the NO in flue gas simultaneously
xand SO
2, but belong to and entirely abandon method.This method will consume a large amount of phosphor resources, and its toxicity is large, and operation requirements is higher.
Fe (II)-EDTA (EDTA represents disodium ethylene diamine tetraacetate) is adopted to remove NO in waste gas.The reaction equation of Fe (II) EDTA and NO is as follows:
Fe(II)EDTA+NO→Fe(II)EDTA(NO) (1)
In nearly three ten years afterwards, many scholars have carried out comparatively systematic research to this reaction, but have not yet to see industrialization report, and the greatest problem affecting wet process complex denitration application is the cycle applications of absorbing liquid.
The circulation regeneration method of absorbing liquid mainly contains bioanalysis, improves the three major types such as absorbent absorbability and electrolysis, wherein applies the most extensive to improve absorbent absorbability.Fe (II) EDTA is easily oxidized to Fe (III) EDTA, and Fe (III) EDTA can not complexing NO, and absorption efficiency is declined rapidly.Regenerate Fe (II) by biocatalytic reduction method, but this method is just in the exploratory stage at present, large-scale application will be obtained also have many problems to need to solve in waste gas pollution control and treatment process.In the application of reducing agent, hydrazine and H
2s reduces Fe (III) EDTA, strengthens the assimilation effect of EDTA Fe, but due to H
2s and hydrazine are all poisonous, are difficult to industrially apply.Someone adopts tannic acid, pyrogaelol and gallic acid to do the second additive to strengthen the absorptive capacity of Fe (II) EDTA, NO in two hours
xremoval efficiency remain on 60 ~ 65% always, effectively improve the reduction effect of poly-phenol mixture.Also someone reports dithionic acid sodium reduction Fe (III) EDTA, and reduction effect is better.Domestic scholars reports reducing/regenerating Fe (III) EDTA such as iron filings, malic acid, vitamin C, but the key issue of this technology to be operating cost high, process route is complicated, also needs further research.
Summary of the invention
Object of the present invention is exactly to overcome the deficiency existing for prior art, provides the method for a kind of hypergravity complexing ferrous smoke-gas wet desulfurization denitration demercuration arsenic integration.
The method of hypergravity complexing of the present invention ferrous smoke-gas wet desulfurization denitration demercuration arsenic integration, comprises the following steps:
1) by temperature be 40 DEG C ~ 120 DEG C and send into desulfurization hypergravity machine containing SOx, NOx, mercury, arsenic flue gas, the concentration being 0 DEG C ~ 40 DEG C with the temperature entering desulfurization hypergravity machine is sulfide solution counter current contacting in desulfurization hypergravity machine rotor packing layer of 0.1 ~ 5.0mol/L, desulfurization, demercuration, dearsenification; Described sulfide is selected from vulcanized sodium, NaHS, ammonium sulfide, ammonium hydro sulfide, potassium sulfide or potassium bisulfide;
2) enter denitration hypergravity machine with the reacted flue gas of sulfide solution from desulfurization hypergravity machine gaseous phase outlet, then be absorbent counter current contacting in denitration hypergravity machine rotor packing layer of 0 DEG C ~ 55 DEG C with the temperature entering denitration hypergravity machine, reaction denitration; Wherein, described absorbent contains complexing ferrous iron and sulfide reducing agent, the complexing agent of described complexing ferrous iron is selected from ethylenediamine tetra-acetic acid (EDTA), N-(2-ethoxy) ethylenediamine-N, N', one or both mixture in N'-triacetic acid (HEDTA), nitrilotriacetic acid (NTA), diethylene triamine pentacetic acid (DTPA) (DTPA), citric acid, described sulfide reducing agent is selected from vulcanized sodium, NaHS, ammonium sulfide, ammonium hydro sulfide, potassium sulfide or potassium bisulfide; Reacted purified gas enters demister from denitration hypergravity machine gaseous phase outlet, enters exhaust system subsequently;
3) after compensator, enter desulfurization subsider from desulfurization hypergravity machine liquid out, by sulphur wherein, insoluble sulfuration salt settling to bottom, after filter filters, reclaim solid, filtrate returns desulfurization subsider;
4) clear liquid on desulfurization subsider top is extracted out and is sent to desulfurization hypergravity machine, flows to desulfurization hypergravity machine together, carry out cyclic absorption desulfurization with after the sulfide on-line mixing of supplementing;
5) after compensator, enter denitration subsider from denitration hypergravity machine liquid out, by sulphur wherein, insoluble sulfuration salt settling to bottom, after filter filters, reclaim solid, filtrate returns denitration subsider;
6) clear liquid on denitration subsider top is extracted out and is sent to denitration hypergravity machine, flows to denitration hypergravity machine together, carry out cyclic absorption denitration with after the sulfide reducing agent on-line mixing of supplementing.
In the present invention, in described absorbent, total Fe concentration is 0.01mol/L ~ 0.5mol/L, and the mol ratio of sulfide and total Fe is 3:1 ~ 5:1, and the mol ratio of described complexing agent and total Fe is 1.02:1 ~ 2:1, and described total Fe refers to Fe
2+and Fe
3+sum.Described sulfide is preferably ammonium sulfide or ammonium hydro sulfide.
In the present invention, the complexing agent of described complexing ferrous iron is preferably the mixture of EDTA and citric acid, the mixture of HEDTA and citric acid, the mixture of EDTA and HEDTA or the mixture of NTA and DTPA.It is that to mix optimum weight ratio be 1:1 ~ 1:3 for 1:1 ~ 1:3, NTA and DTPA that EDTA and citric acid mixing optimum weight ratio to be 1:2 ~ 1:4, HEDTA with citric acid mixing optimum weight ratio be 1:3 ~ 1:6, EDTA and HEDTA mixes optimum weight ratio.
Beneficial effect of the present invention is: first utilize inorganic sulphide to absorb SOx, in desulfurization simultaneously, the toxic heavy metals such as inorganic sulphide and the mercury in flue gas, arsenic react raw insoluble become sulphurizing salt, then utilize complexing ferrous absorption NOx denitration, inorganic sulphide is as reducing agent absorbent regeneration.The present invention adopts hypergravity machine as gas-liquid mass transfer strengthening device, is conducive to SOx, NOx, mercury, the removing of arsenic.
The present invention, in desulfurization, adopts inorganic sulphide to absorb SOx, not only can obtain sulphur, the heavy metals such as mercury, arsenic and lead are converted into insoluble sulfur compound simultaneously, and the sulphite of generation and thiosulfate may be used for producing the sulfide as reducing agent.
The present invention is in denitration, and adopt cheap inorganic sulphide, Complexing Iron can not only be reduced to complexing ferrous iron, and the NO of complexed absorption can be reduced to nitrogen, the regeneration efficiency of absorbent is high, absorbing liquid application capable of circulation.The product sulphur of the oxidized generation of reducing agent inorganic sulphide, can reclaim, and is processed as high-quality sulfur product, can not produce secondary pollution.
Present invention process is simple, and absorption efficiency is high, and desulfurization degree is more than 99%, and denitration rate, more than 96%, can remove the mercury in flue gas and arsenic substantially completely.
Detailed description of the invention
In order to explain the present invention better, below in conjunction with the drawings and specific embodiments, the present invention is described in further detail, but they do not form restriction to the present invention.
The size of two hypergravity machines of the present invention's test: rotor interior diameter 250mm, rotor outside diameter 600mm, rotor height 100mm.
Embodiment 1
The method of hypergravity complexing ferrous smoke-gas wet desulfurization denitration demercuration arsenic integration, as shown in Figure 1, comprises the following steps:
1) be 120 by temperature after dedusting
flue gas is with 400Nm
3the flow velocity of/h sends into desulfurization hypergravity machine, SO in flue gas
2concentration is 600 ~ 1000ppmv, NO concentration is 500 ~ 800ppmv, arsenic content 6 ~ 20 μ g/Nm
3, mercury content 9 ~ 17 μ g/Nm
3, oxygen concentration 2%v, flue gas is with to squeeze into temperature in desulfurization hypergravity by storage tank through pump be 20
sodium sulfide solution is counter current contacting in hypergravity machine rotor packing layer, desulfurization, demercuration, dearsenification, and the volume ratio of flue gas and sodium sulfide solution is 100:1, and the concentration of sodium sulfide solution is 0.1mol/L;
2) enter denitration hypergravity machine with the reacted flue gas of sodium sulfide solution from desulfurization hypergravity machine gaseous phase outlet, then be absorbent counter current contacting in denitration hypergravity machine rotor packing layer of 20 DEG C with the temperature entering denitration hypergravity machine, reaction denitration; Wherein, absorbent consists of vulcanized sodium, HEDTA complexing is ferrous, and total Fe concentration is the mol ratio 1.02:1 of 0.01mol/L, HEDTA and total Fe, and the mol ratio of vulcanized sodium and total iron is 5:1, and the volume ratio of flue gas and absorbent is 100:1; Reacted purified gas enters demister from denitration hypergravity machine gaseous phase outlet, enters exhaust system subsequently; Purified gas adopts infrared spectrometer to detect, SO in purified gas
2concentration is 5ppmv, NO concentration is 7ppmv, adopts atomic absorption spectrography (AAS) to detect heavy metal, can't detect arsenic, mercury;
3) after compensator, enter desulfurization subsider from desulfurization hypergravity machine liquid out, by sulphur wherein, insoluble sulfuration salt settling to bottom, after filter filters, reclaim solid, filtrate returns desulfurization subsider;
4) clear liquid on desulfurization subsider top is extracted out and is sent to desulfurization hypergravity machine, flows to desulfurization hypergravity machine together, carry out cyclic absorption desulfurization with after the sulfide on-line mixing of supplementing;
5) after compensator, enter denitration subsider from denitration hypergravity machine liquid out, by sulphur wherein, insoluble sulfuration salt settling to bottom, after filter filters, reclaim solid, filtrate returns denitration subsider;
(6) clear liquid on denitration subsider top is extracted out and is sent to denitration hypergravity machine, flows to denitration hypergravity machine together, carry out cyclic absorption denitration with after the sulfide reducing agent on-line mixing of supplementing.
Embodiment 2
The method of hypergravity complexing ferrous smoke-gas wet desulfurization denitration demercuration arsenic integration, as shown in Figure 1, comprises the following steps:
1) be 40 by the temperature after dedusting
gas is with 400Nm
3the flow velocity of/h sends into desulfurization hypergravity machine, SO in flue gas
2concentration is 1400 ~ 2000ppmv, NO concentration is 500 ~ 800ppmv, arsenic content 6 ~ 20 μ g/Nm
3, mercury content 9 ~ 17 μ g/Nm
3, oxygen concentration 3%v, flue gas is with to squeeze into temperature in desulfurization hypergravity by storage tank through pump be 0
the NaHS aqueous solution is counter current contacting in hypergravity machine rotor packing layer, desulfurization, demercuration, dearsenification, and the volume ratio of flue gas and the NaHS aqueous solution is 1000:1, and the concentration of the NaHS aqueous solution is 1.0mol/L;
2) flue gas and after NaHS reactant aqueous solution enters denitration hypergravity machine from desulfurization hypergravity machine gaseous phase outlet, then is absorbent counter current contacting in denitration hypergravity machine rotor packing layer of 0 DEG C with the temperature entering denitration hypergravity machine, reaction denitration; Wherein, absorbent consists of NaHS, EDTA complexing is ferrous, and total Fe concentration is the mol ratio 1.5:1 of 0.5mol/L, EDTA and total Fe, and the mol ratio of NaHS and total iron is 4:1, and the volume ratio of flue gas and absorbent is 500:1; Reacted purified gas enters demister from denitration hypergravity machine gaseous phase outlet, enters exhaust system subsequently; Purified gas adopts infrared spectrometer to detect, SO in purified gas
2concentration is 10ppmv, NO concentration is 17ppmv, adopts atomic absorption spectrography (AAS) to detect heavy metal, can't detect arsenic, mercury;
3) after compensator, enter desulfurization subsider from desulfurization hypergravity machine liquid out, by sulphur wherein, insoluble sulfuration salt settling to bottom, after filter filters, reclaim solid, filtrate returns desulfurization subsider;
4) clear liquid on desulfurization subsider top is extracted out and is sent to desulfurization hypergravity machine, flows to desulfurization hypergravity machine together, carry out cyclic absorption desulfurization with after the sulfide on-line mixing of supplementing;
5) after compensator, enter denitration subsider from denitration hypergravity machine liquid out, by sulphur wherein, insoluble sulfuration salt settling to bottom, after filter filters, reclaim solid, filtrate returns denitration subsider;
(6) clear liquid on denitration subsider top is extracted out and is sent to denitration hypergravity machine, flows to denitration hypergravity machine together, carry out cyclic absorption denitration with after the sulfide reducing agent on-line mixing of supplementing.
Embodiment 3
The method of hypergravity complexing ferrous smoke-gas wet desulfurization denitration demercuration arsenic integration, as shown in Figure 1, comprises the following steps:
1) be 80 by the temperature after dedusting
gas is with 400Nm
3the flow velocity of/h sends into desulfurization hypergravity machine, SO in flue gas
2concentration is 1600 ~ 2400ppmv, NO concentration is 500 ~ 800ppmv, arsenic content 6 ~ 20 μ g/Nm
3, mercury content 9 ~ 17 μ g/Nm
3oxygen concentration 5%v, flue gas with squeeze into through pump ammonium sulfide solution counter current contacting in hypergravity machine rotor packing layer that temperature in desulfurization hypergravity is 35 DEG C by storage tank, desulfurization, demercuration, dearsenification, the volume ratio of flue gas and ammonium sulfide solution is 800:1, and the concentration of ammonium sulfide solution is 2.0mol/L;
2) enter denitration hypergravity machine with the reacted flue gas of ammonium sulfide solution from desulfurization hypergravity machine gaseous phase outlet, then be absorbent counter current contacting in denitration hypergravity machine rotor packing layer of 55 DEG C with the temperature entering denitration hypergravity machine, reaction denitration; Wherein, absorbent consists of ammonium sulfide, NTA complexing is ferrous, and total Fe concentration is the mol ratio 2:1 of 0.3mol/L, NTA and total Fe, and the mol ratio of ammonium sulfide and total iron is 3:1, and the volume ratio of flue gas and absorbent is 1000:1; Reacted purified gas enters demister from denitration hypergravity machine gaseous phase outlet, enters exhaust system subsequently; Purified gas adopts infrared spectrometer to detect, SO in purified gas
2concentration is 12ppmv, NO concentration is 15ppmv, adopts atomic absorption spectrography (AAS) to detect heavy metal, can't detect arsenic, mercury;
3) after compensator, enter desulfurization subsider from desulfurization hypergravity machine liquid out, by sulphur wherein, insoluble sulfuration salt settling to bottom, after filter filters, reclaim solid, filtrate returns desulfurization subsider;
4) clear liquid on desulfurization subsider top is extracted out and is sent to desulfurization hypergravity machine, flows to desulfurization hypergravity machine together, carry out cyclic absorption desulfurization with after the sulfide on-line mixing of supplementing;
5) after compensator, enter denitration subsider from denitration hypergravity machine liquid out, by sulphur wherein, insoluble sulfuration salt settling to bottom, after filter filters, reclaim solid, filtrate returns denitration subsider;
(6) clear liquid on denitration subsider top is extracted out and is sent to denitration hypergravity machine, flows to denitration hypergravity machine together, carry out cyclic absorption denitration with after the sulfide reducing agent on-line mixing of supplementing.
Embodiment 4
The method of hypergravity complexing ferrous smoke-gas wet desulfurization denitration demercuration arsenic integration, as shown in Figure 1, comprises the following steps:
1) be 60 by the temperature after dedusting
gas is with 400Nm
3the flow velocity of/h sends into desulfurization hypergravity machine, SO in flue gas
2concentration is 600 ~ 1000ppmv, NO concentration is 800 ~ 1200ppmv, arsenic content 6 ~ 20 μ g/Nm
3, mercury content 9 ~ 17 μ g/Nm
3oxygen concentration 6%v, flue gas with squeeze into through pump ammonium hydro sulfide aqueous solution counter current contacting in hypergravity machine rotor packing layer that temperature in desulfurization hypergravity is 40 DEG C by storage tank, desulfurization, demercuration, dearsenification, the volume ratio of flue gas and the ammonium hydro sulfide aqueous solution is 800:1, and the concentration of the ammonium hydro sulfide aqueous solution is 3.0mol/L;
2) flue gas and after ammonium hydro sulfide reactant aqueous solution enters denitration hypergravity machine from desulfurization hypergravity machine gaseous phase outlet, then is absorbent counter current contacting in denitration hypergravity machine rotor packing layer of 45 DEG C with the temperature entering denitration hypergravity machine, reaction denitration; Wherein, absorbent consists of ammonium hydro sulfide, DTPA complexing is ferrous, and total Fe concentration is the mol ratio 1.2:1 of 0.3mol/L, DTPA and total Fe, and the mol ratio of ammonium hydro sulfide and total iron is 5:1, and the volume ratio of flue gas and absorbent is 800:1; Reacted purified gas enters demister from denitration hypergravity machine gaseous phase outlet, enters exhaust system subsequently; Purified gas adopts infrared spectrometer to detect, SO in purified gas
2concentration is 6ppmv, NO concentration is 20ppmv, adopts atomic absorption spectrography (AAS) to detect heavy metal, can't detect arsenic, mercury;
3) after compensator, enter desulfurization subsider from desulfurization hypergravity machine liquid out, by sulphur wherein, insoluble sulfuration salt settling to bottom, after filter filters, reclaim solid, filtrate returns desulfurization subsider;
4) clear liquid on desulfurization subsider top is extracted out and is sent to desulfurization hypergravity machine, flows to desulfurization hypergravity machine together, carry out cyclic absorption desulfurization with after the sulfide on-line mixing of supplementing;
5) after compensator, enter denitration subsider from denitration hypergravity machine liquid out, by sulphur wherein, insoluble sulfuration salt settling to bottom, after filter filters, reclaim solid, filtrate returns denitration subsider;
(6) clear liquid on denitration subsider top is extracted out and is sent to denitration hypergravity machine, flows to denitration hypergravity machine together, carry out cyclic absorption denitration with after the sulfide reducing agent on-line mixing of supplementing.
Embodiment 5
The method of hypergravity complexing ferrous smoke-gas wet desulfurization denitration demercuration arsenic integration, as shown in Figure 1, comprises the following steps:
1) be that 75 DEG C of flue gases are with 400Nm by the temperature after dedusting
3the flow velocity of/h sends into desulfurization hypergravity machine, SO in flue gas
2concentration is 2300 ~ 3100ppmv, NO concentration is 800 ~ 1200ppmv, arsenic content 6 ~ 20 μ g/Nm
3, mercury content 9 ~ 17 μ g/Nm
3oxygen concentration 6%v, flue gas with squeeze into through pump potassium sulfide aqueous solution counter current contacting in hypergravity machine rotor packing layer that temperature in desulfurization hypergravity is 30 DEG C by storage tank, desulfurization, demercuration, dearsenification, the volume ratio of flue gas and potassium sulfide aqueous solution is 1000:1, and the concentration of potassium sulfide aqueous solution is 3.0mol/L;
2) enter denitration hypergravity machine with the reacted flue gas of potassium sulfide aqueous solution from desulfurization hypergravity machine gaseous phase outlet, then be absorbent counter current contacting in denitration hypergravity machine rotor packing layer of 50 DEG C with the temperature entering denitration hypergravity machine, reaction denitration; Wherein, absorbent consists of potassium sulfide, EDTA+ citric acid complex is ferrous, total Fe concentration is 0.2mol/L, the mol ratio 1.2:1 of EDTA+ citric acid and total Fe, EDTA is 1:2 with citric acid mixing optimum weight ratio, the mol ratio of potassium sulfide and total iron is 3:1, and the volume ratio of flue gas and absorbent is 800:1; Reacted purified gas enters demister from denitration hypergravity machine gaseous phase outlet, enters exhaust system subsequently; Purified gas adopts infrared spectrometer to detect, SO in purified gas
2concentration is 6ppmv, NO concentration is 10ppmv, adopts atomic absorption spectrography (AAS) to detect heavy metal, can't detect arsenic, mercury;
3) after compensator, enter desulfurization subsider from desulfurization hypergravity machine liquid out, by sulphur wherein, insoluble sulfuration salt settling to bottom, after filter filters, reclaim solid, filtrate returns desulfurization subsider;
4) clear liquid on desulfurization subsider top is extracted out and is sent to desulfurization hypergravity machine, flows to desulfurization hypergravity machine together, carry out cyclic absorption desulfurization with after the sulfide on-line mixing of supplementing;
5) after compensator, enter denitration subsider from denitration hypergravity machine liquid out, by sulphur wherein, insoluble sulfuration salt settling to bottom, after filter filters, reclaim solid, filtrate returns denitration subsider;
(6) clear liquid on denitration subsider top is extracted out and is sent to denitration hypergravity machine, flows to denitration hypergravity machine together, carry out cyclic absorption denitration with after the sulfide reducing agent on-line mixing of supplementing.
Embodiment 6
The method of hypergravity complexing ferrous smoke-gas wet desulfurization denitration demercuration arsenic integration, as shown in Figure 1, comprises the following steps:
1) be that 90 DEG C of flue gases are with 400Nm by the temperature after dedusting
3the flow velocity of/h sends into desulfurization hypergravity machine, SO in flue gas
2concentration is 2300 ~ 3100ppmv, NO concentration is 800 ~ 1200ppmv, arsenic content 6 ~ 20 μ g/Nm
3, mercury content 9 ~ 17 μ g/Nm
3oxygen concentration 7%v, flue gas with squeeze into through pump potassium bisulfide aqueous solution counter current contacting in hypergravity machine rotor packing layer that temperature in desulfurization hypergravity is 20 DEG C by storage tank, desulfurization, demercuration, dearsenification, the volume ratio of flue gas and the potassium bisulfide aqueous solution is 1000:1, and the concentration of the potassium bisulfide aqueous solution is 5.0mol/L;
2) flue gas and after potassium bisulfide reactant aqueous solution enters denitration hypergravity machine from desulfurization hypergravity machine gaseous phase outlet, then is absorbent counter current contacting in denitration hypergravity machine rotor packing layer of 50 DEG C with the temperature entering denitration hypergravity machine, reaction denitration; Wherein, absorbent consists of potassium bisulfide, HEDTA+ citric acid complex is ferrous, total Fe concentration is 0.4mol/L, the mol ratio 1.2:1 of HEDTA+ citric acid and total Fe, HEDTA is 1:6 with citric acid mixing optimum weight ratio, the mol ratio of potassium bisulfide and total iron is 3:1, and the volume ratio of flue gas and absorbent is 800:1; Reacted purified gas enters demister from denitration hypergravity machine gaseous phase outlet, enters exhaust system subsequently; Purified gas adopts infrared spectrometer to detect, SO in purified gas
2concentration is 5ppmv, NO concentration is 6ppmv, adopts atomic absorption spectrography (AAS) to detect heavy metal, can't detect arsenic, mercury;
3) after compensator, enter desulfurization subsider from desulfurization hypergravity machine liquid out, by sulphur wherein, insoluble sulfuration salt settling to bottom, after filter filters, reclaim solid, filtrate returns desulfurization subsider;
4) clear liquid on desulfurization subsider top is extracted out and is sent to desulfurization hypergravity machine, flows to desulfurization hypergravity machine together, carry out cyclic absorption desulfurization with after the sulfide on-line mixing of supplementing;
5) after compensator, enter denitration subsider from denitration hypergravity machine liquid out, by sulphur wherein, insoluble sulfuration salt settling to bottom, after filter filters, reclaim solid, filtrate returns denitration subsider;
(6) clear liquid on denitration subsider top is extracted out and is sent to denitration hypergravity machine, flows to denitration hypergravity machine together, carry out cyclic absorption denitration with after the sulfide reducing agent on-line mixing of supplementing.
Embodiment 7
The method of hypergravity complexing ferrous smoke-gas wet desulfurization denitration demercuration arsenic integration, as shown in Figure 1, comprises the following steps:
1) be that 85 DEG C of flue gases are with 400Nm by the temperature after dedusting
3the flow velocity of/h sends into desulfurization hypergravity machine, SO in flue gas
2concentration is 2300 ~ 3100ppmv, NO concentration is 1000 ~ 1500ppmv, arsenic content 6 ~ 20 μ g/Nm
3, mercury content 9 ~ 17 μ g/Nm
3oxygen concentration 7%v, flue gas with squeeze into through pump sodium sulfide solution counter current contacting in hypergravity machine rotor packing layer that temperature in desulfurization hypergravity is 25 DEG C by storage tank, desulfurization, demercuration, dearsenification, the volume ratio of flue gas and sodium sulfide solution is 1000:1, and the concentration of sodium sulfide solution is 4.0mol/L;
2) enter denitration hypergravity machine with the reacted flue gas of sodium sulfide solution from desulfurization hypergravity machine gaseous phase outlet, then be absorbent counter current contacting in denitration hypergravity machine rotor packing layer of 40 DEG C with the temperature entering denitration hypergravity machine, reaction denitration; Wherein, absorbent consists of vulcanized sodium, EDTA+HEDTA complexing is ferrous, total Fe concentration is 0.15mol/L, the mol ratio 1.25:1 of EDTA+HEDTA and total Fe, it is 1:2 that EDTA and HEDTA mixes optimum weight ratio, the mol ratio of vulcanized sodium and total iron is 3:1, and the volume ratio of flue gas and absorbent is 800:1; Reacted purified gas enters demister from denitration hypergravity machine gaseous phase outlet, enters exhaust system subsequently; Purified gas adopts infrared spectrometer to detect, SO in purified gas
2concentration is 7ppmv, NO concentration is 8ppmv, adopts atomic absorption spectrography (AAS) to detect heavy metal, can't detect arsenic, mercury;
3) after compensator, enter desulfurization subsider from desulfurization hypergravity machine liquid out, by sulphur wherein, insoluble sulfuration salt settling to bottom, after filter filters, reclaim solid, filtrate returns desulfurization subsider;
4) clear liquid on desulfurization subsider top is extracted out and is sent to desulfurization hypergravity machine, flows to desulfurization hypergravity machine together, carry out cyclic absorption desulfurization with after the sulfide on-line mixing of supplementing;
5) after compensator, enter denitration subsider from denitration hypergravity machine liquid out, by sulphur wherein, insoluble sulfuration salt settling to bottom, after filter filters, reclaim solid, filtrate returns denitration subsider;
(6) clear liquid on denitration subsider top is extracted out and is sent to denitration hypergravity machine, flows to denitration hypergravity machine together, carry out cyclic absorption denitration with after the sulfide reducing agent on-line mixing of supplementing.
Embodiment 8
The method of hypergravity complexing ferrous smoke-gas wet desulfurization denitration demercuration arsenic integration, as shown in Figure 1, comprises the following steps:
1) be that 50 DEG C of flue gases are with 400Nm by the temperature after dedusting
3the flow velocity of/h sends into desulfurization hypergravity machine, SO in flue gas
2concentration is 2300 ~ 3100ppmv, NO concentration is 800 ~ 1200ppmv, arsenic content 6 ~ 20 μ g/Nm
3, mercury content 9 ~ 17 μ g/Nm
3oxygen concentration 8%v, flue gas with squeeze into through pump potassium bisulfide aqueous solution counter current contacting in hypergravity machine rotor packing layer that temperature in desulfurization hypergravity is 35 DEG C by storage tank, desulfurization, demercuration, dearsenification, the volume ratio of flue gas and the potassium bisulfide aqueous solution is 1000:1, and the concentration of the potassium bisulfide aqueous solution is 3.5mol/L;
2) enter denitration hypergravity machine with the reacted flue gas of sodium sulfide solution from desulfurization hypergravity machine gaseous phase outlet, then be absorbent counter current contacting in denitration hypergravity machine rotor packing layer of 40 DEG C with the temperature entering denitration hypergravity machine, reaction denitration; Wherein, absorbent consists of vulcanized sodium, DTPA+NTA complexing is ferrous, and total Fe concentration is 0.25mol/L, the mol ratio 1.3:1 of DTPA+NTA and total Fe, it is 1:3 that NTA and DTPA mixes optimum weight ratio, and the mol ratio of vulcanized sodium and total iron is 3:1, and the volume ratio of flue gas and absorbent is 800:1; Reacted purified gas enters demister from denitration hypergravity machine gaseous phase outlet, enters exhaust system subsequently; Purified gas adopts infrared spectrometer to detect, SO in purified gas
2concentration is 5ppmv, NO concentration is 8ppmv, adopts atomic absorption spectrography (AAS) to detect heavy metal, can't detect arsenic, mercury;
3) after compensator, enter desulfurization subsider from desulfurization hypergravity machine liquid out, by sulphur wherein, insoluble sulfuration salt settling to bottom, after filter filters, reclaim solid, filtrate returns desulfurization subsider;
4) clear liquid on desulfurization subsider top is extracted out and is sent to desulfurization hypergravity machine, flows to desulfurization hypergravity machine together, carry out cyclic absorption desulfurization with after the sulfide on-line mixing of supplementing;
5) after compensator, enter denitration subsider from denitration hypergravity machine liquid out, by sulphur wherein, insoluble sulfuration salt settling to bottom, after filter filters, reclaim solid, filtrate returns denitration subsider;
(6) clear liquid on denitration subsider top is extracted out and is sent to denitration hypergravity machine, flows to denitration hypergravity machine together, carry out cyclic absorption denitration with after the sulfide reducing agent on-line mixing of supplementing.