CN105833698B

CN105833698B - A kind of method using the sulfur-containing smoke gas production concentrated sulfuric acid

Info

Publication number: CN105833698B
Application number: CN201510020879.0A
Authority: CN
Inventors: 谢志成; ***; 冯晓霞; 王培功
Original assignee: Hunan China Tianyuan Environmental Engineering Co Ltd
Current assignee: Hunan China Tianyuan Environmental Engineering Co., Ltd.
Priority date: 2015-01-15
Filing date: 2015-01-15
Publication date: 2018-05-25
Anticipated expiration: 2035-01-15
Also published as: CN105833698A

Abstract

The present invention provides a kind of method using the sulfur-containing smoke gas production concentrated sulfuric acid, wherein, this method comprises the following steps：(a) sulfur-containing smoke gas with absorbent is contacted, obtains the flue gas after desulfurization and absorbing liquid；(b) absorbing liquid is imported into bipolar membrane electrodialysis device and carries out electrodialysis, obtain can continue to absorb SO₂The first dialysate and be enriched H₂SO₃The second dialysate；(c) second dialysate is desorbed, obtain stripping liquid and contains SO₂Stripping gas；(d) by the SO in the stripping gas₂It is oxidized to SO₃, the stripping liquid is split into the first stripping liquid and the second stripping liquid, the SO obtained with the first stripping liquid sorption enhanced₃To generate H₂SO₄；The second stripping liquid reuse is enriched with H into the electrodialysis plant₂SO₃.The present invention can be by the SO in flue gas₂The concentrated sulfuric acid is fully converted into, and can realize no effuent discharge substantially, effectively recycles absorbing liquid.

Description

A kind of method using the sulfur-containing smoke gas production concentrated sulfuric acid

Technical field

The present invention relates to field of chemical engineering, and in particular, to a kind of method using the sulfur-containing smoke gas production concentrated sulfuric acid.

Background technology

Flue gas refers to the mixture of gas and flue dust.It is boiler, industrial furnace, thermal power plant, coke oven, cement plant, blast furnace, flat The operation of the chemical industry equipments such as stove, converter, electric furnace and catalytic cracking (FCC) device can all generate substantial amounts of flue gas.It is contained in flue gas The air pollutants such as a large amount of sulfur and nitrogen oxides bring a series of environmental problems.It reduces and contains oxysulfide and nitrogen oxygen The discharge of the air pollutants such as compound is the task of top priority of environmental protection.Such as standard GB/T 13271-91《Boiler air is dirty Contaminate object discharge standard》、GB9078-1996《Industrial furnace atmosphere pollutants emission standards》、GB13223-1996《Thermal power plant's air Pollutant emission standard》、GB16171-1996《Coke oven atmosphere pollutants emission standards》And GB4915-1996《Cement plant is big Gas pollutant emission standard》All define the discharge standard of pollutant in flue gas.Therefore, it is necessary to desulphurization and denitration is carried out to flue gas After dust removal process, it could be discharged.

In the flue gas desulfurization technique of commercial Application, wet desulphurization is one of method the most frequently used and more mature at present. Common FCC regenerated flue gas absorption process have the WGS wet scrubbings of EXXON companies, Uop Inc. THIOPAQ biotechnologys, EDV wet scrubbing technologies of Belco companies etc..The EDV Wet Flue Gas Desulfurization Technologies of wherein Belco companies have become industrial gas Body purifies and SO₂One of main method of recycling.The commercial Application since 1994, EDV Wet Flue Gas Desulfurization Technologies are just shown Go out excellent operability and reliability.So far, mating EDV facilities of more than 90 sets catalytic cracking units, maximum production Can be 5Mt/a.But greatest problem existing for EDV Wet Flue Gas Desulfurization Technologies is that the technology can consume a large amount of water and NaOH As absorbing liquid, and with the SO in flue gas₂It is oxidized to be changed into substantial amounts of sodium sulfate salt solution after reaction, so as to generate The emission problem of a large amount of high-salt wastewaters.

The content of the invention

The object of the present invention is to provide a kind of method, this method is capable of the absorbing liquid conversion of wet desulfurizing and dust collecting system generation For the lye of reusable edible, SO is made full use of₂It produces the concentrated sulfuric acid, realizes no effuent discharge substantially.

It was found by the inventors of the present invention that absorbing liquid is carried out electrodialysis by bipolar membrane electrodialysis device, and make full use of It is enriched H₂SO₃The stripping liquid that is obtained after desorption of dialysate in be unable to the H of Desorption separation₂SO₃With dilute H₂SO₄, it is impossible to The H of Desorption separation₂SO₃With dilute H₂SO₄Also be transferred in the concentrated sulfuric acid, can effectively recycle absorbing liquid and reduce power consumption and It realizes no effuent discharge, and realizes the tail gas zero-emission of Sulphuric acid workshop section, result in the present invention.

To achieve these goals, the present invention provides a kind of method using the sulfur-containing smoke gas production concentrated sulfuric acid, wherein, it should Method includes the following steps：(a) sulfur-containing smoke gas with absorbent is contacted, obtains the flue gas after desulfurization and absorbing liquid；The absorption Agent is alkaline aqueous solution；(b) absorbing liquid is imported into bipolar membrane electrodialysis device and carries out electrodialysis, obtain can continue to absorb SO₂The first dialysate and be enriched H₂SO₃The second dialysate；Using the first dialysate reuse as the part of absorbent Or it is all contacted with flue gas；(c) second dialysate is desorbed, obtain stripping liquid and contains SO₂Stripping gas； (d) by the SO in the stripping gas₂It is oxidized to SO₃, the stripping liquid is split into the first stripping liquid and the second stripping liquid, makes institute State the SO that the water in the first stripping liquid is obtained with oxidation₃Reaction generation H₂SO₄；By the second stripping liquid reuse to the electric osmose H is enriched in analysis apparatus₂SO₃。

Through the above technical solutions, the present invention can be by the SO in flue gas₂The concentrated sulfuric acid is fully converted into, it is particularly abundant It make use of and be enriched H₂SO₃The stripping liquid that is obtained after desorption of dialysate in be unable to the H of Desorption separation₂SO₃With dilute H₂SO₄, will It is unable to dilute H of Desorption separation₂SO₄Also it is transferred in the concentrated sulfuric acid, it is impossible to the H of Desorption separation₂SO₃It is also combined into oxidation and turns Change into sulfuric acid, and can realize no effuent discharge substantially, effectively recycle absorbing liquid.

Other features and advantages of the present invention will be described in detail in subsequent specific embodiment part.

Description of the drawings

Attached drawing is for providing a further understanding of the present invention, and a part for constitution instruction, with following tool Body embodiment is together for explaining the present invention, but be not construed as limiting the invention.In the accompanying drawings：

Fig. 1 is the apparatus structure using the sulfur-containing smoke gas production concentrated sulfuric acid used in a kind of preferred embodiment of the invention Schematic diagram.

Fig. 2 is the structural representation of two compartment bipolar membrane electrodialysis devices used in a kind of preferred embodiment of the invention Figure.

Fig. 3 is the apparatus structure using the sulfur-containing smoke gas production concentrated sulfuric acid used in a kind of preferred embodiment of the invention Schematic diagram.

Fig. 4 is the structural representation of two compartment bipolar membrane electrodialysis devices used in a kind of preferred embodiment of the invention Figure.

Fig. 5 is the structural representation of three compartment bipolar membrane electrodialysis devices used in a kind of preferred embodiment of the invention Figure.

Fig. 6 is the apparatus structure using the sulfur-containing smoke gas production concentrated sulfuric acid used in a kind of preferred embodiment of the invention Schematic diagram.

Reference sign

1 desulfurizing tower

11 smoke inlet, 12 exhanst gas outlet

2 solid-liquid separators

301 2 compartment bipolar membrane electrodialysis device, 302 2 compartment bipolar membrane electrodialysis device

303 3 compartment bipolar membrane electrodialysis devices

31 first alkali room, 32 first salt room

33 second salt room, 34 first sour room

The 3rd salt room of 35 second alkali room 36

37 second sour rooms

4 desorbers

41 flow divider, 42 pipeline

43 pipelines

5 drier, 51 First Heat Exchanger

52 second heat exchanger, 53 SO₂Converter

The 4th heat exchanger of 54 the 3rd heat exchanger 55

56 first sulfuric acid absorption tower, 57 second sulfuric acid absorption tower

58 sulfuric acid dilution devices

581 pipeline, 582 pipeline

583 pipeline, 584 pipeline

585 pipeline, 586 pipeline

6 absorbing liquid circulating pumps

7 filter, 8 liquid drop separator

101 first cathode, 102 first Bipolar Membrane

103 first cation-exchange membrane, 104 second Bipolar Membrane

105 first anode, 106 first salt room exports

107 first salt chamber inlet, 108 first alkali room entrance

109 first alkali rooms export 113 cation-exchange membranes

114 Bipolar Membrane, 130 first pole film

131 second pole film, 136 first sour room exports

137 first sour room entrance, 138 second salt chamber inlet

139 second salt rooms export 140 first anion-exchange membranes

The 3rd Bipolar Membrane of 201 second cathode 202

203 second cation-exchange membrane, 204 second anion-exchange membrane

205 the 4th Bipolar Membrane, 206 second plate

207 second alkali rooms export the outlet of 208 second sour rooms

209 the 3rd salt rooms export 210 the 3rd salt chamber inlets

211 second sour room entrance, 212 second alkali room entrance

223 cation-exchange membrane, 224 anion-exchange membrane

The 3rd pole film of 225 Bipolar Membrane 230

231 quadrupole films

Specific embodiment

The specific embodiment of the present invention is described in detail below in conjunction with attached drawing.It should be appreciated that this place is retouched The specific embodiment stated is merely to illustrate and explain the present invention, and is not intended to limit the invention.

With reference to figure 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5 and Fig. 6, the concentrated sulfuric acid is produced using sulfur-containing smoke gas the present invention provides a kind of Method, this method can be used for the desulfurization process of various sulfur-containing smoke gas in chemical field, and the sulfur-containing smoke gas includes but not limited to By boiler, industrial furnace, thermal power plant, coke oven, cement plant, blast furnace, open hearth, converter, electric furnace and catalytic cracking (FCC) device etc. The sulfur-containing smoke gas that chemical industry equipment generates.In the sulfur-containing smoke gas, by volume, the content of sulfur dioxide can be 500- 3000ppm。

The method using the sulfur-containing smoke gas production concentrated sulfuric acid provided according to the present invention, wherein, this method comprises the following steps： (a) sulfur-containing smoke gas with absorbent is contacted, obtains the flue gas after desulfurization and absorbing liquid；The absorbent is alkaline aqueous solution；(b) The absorbing liquid is imported into bipolar membrane electrodialysis device and carries out electrodialysis, obtains can continue to absorb SO₂The first dialysate and It is enriched H₂SO₃The second dialysate；It is connect the first dialysate reuse as the part or all of and flue gas of absorbent It touches；(c) second dialysate is desorbed, obtain stripping liquid and contains SO₂Stripping gas；It (d) will be in the stripping gas SO₂It is oxidized to SO₃, the stripping liquid is split into the first stripping liquid and the second stripping liquid, makes the water in first stripping liquid With aoxidizing obtained SO₃Reaction generation H₂SO₄；The second stripping liquid reuse is enriched with H into the electrodialysis plant₂SO₃。

Wherein, the sulfur-containing smoke gas can pass through the smoke inlet 11 of desulfurizing tower 1 and enter desulfurizing tower 1, in the desulfurizing tower 1 with Absorbent is contacted, and to obtain desulfurization process, then discharges desulfurizing tower 1 by exhanst gas outlet 12.Wherein, the desulfurization process It can individually carry out, can also be carried out at the same time with the processing of denitration and/or dedusting in desulfurizing tower 1.

Wherein, the type of the desulfurizing tower 1 does not require particularly, as long as contact of the flue gas with absorbent can be completed i.e. Can, include but not limited to plate column, bubble absorbing tower, stirring bubble absorbing tower, injector, Venturi tube, spray tower, packing material absorbing At least one of tower and film-falling absorption tower.

Wherein, it is connected with the absorbing liquid recovery system for including the bipolar membrane electrodialysis device on the desulfurizing tower 1.

Wherein, the absorbent is in alkaline aqueous solution for pH value, and pH value can be more than 8.The absorbent can be with By water come dissolved sulfur dioxide, the absorbent can also increase the uptake to sulfur dioxide by alkaline active ingredient. The alkalescence active ingredient includes but not limited to NaOH, Na₂SO₃, at least one of ammonium hydroxide and water-soluble organic amine.

Wherein, the absorbent can be the aqueous solution containing NaOH；Alternatively, the absorbent can also be containing Na₂SO₃Aqueous solution；Or the absorbent can be not only containing NaOH but also to have contained Na₂SO₃Aqueous solution.The absorption Agent is into smoke contacts, the oxysulfide in flue gas is absorbed by absorbent, and the absorbent after contact is converted into after desulfurizing tower 1 Absorbing liquid is by absorbing liquid outlet discharge.Contain NaHSO in the absorbing liquid of discharge₃、Na₂SO₃And Na₂SO₄, recycled by absorbing liquid The recovery processing of system is converted into absorbent and is recycled.Wherein, bipolar membrane electrodialysis device can be used for the suction of discharge Receive the NaHSO in liquid₃And Na₂SO₃It is separated into NaOH and H₂SO₃.Bipolar membrane electrodialysis device can be used for the absorbing liquid of discharge In NaHSO₃It is separated into NaOH and Na₂SO₃Mixture and H₂SO₃.Desorber 4 can be used for discharging bipolar membrane electrodialysis device H₂SO₃With SO₂Formal solution suction go out.

A kind of preferred embodiment provided according to the present invention, wherein, the bipolar membrane electrodialysis device includes two compartments Bipolar membrane electrodialysis device 301；The two compartments bipolar membrane electrodialysis device 301, which has, is arranged at the first cathode 101 and the first anode Two compartment bipolar membrane electrodialysis film pair of at least one set between 105, the two compartments bipolar membrane electrodialysis film is to including first pair Pole film 102, the first cation-exchange membrane 103 and the second Bipolar Membrane 104, the first Bipolar Membrane 102 and the first cation-exchange membrane 103 Between form the first alkali room 31, the first salt room 32 is formed between the second Bipolar Membrane 104 and the first cation-exchange membrane 103；Wherein, Carrying out the electrodialytic step includes：The absorbing liquid is passed through the first salt room in two compartment bipolar membrane electrodialysis devices 301 32 carry out electrodialysis, obtain can continue to absorb SO in the first alkali room 31₂The first dialysate, in the first salt room 32 It obtains being enriched H₂SO₃The second dialysate.

Wherein, at least one first salt chamber inlet 107 and at least one first salt room can go out on the first salt room 32 Mouth 106.First salt chamber inlet 107 can be exported with the absorbing liquid of desulfurizing tower 1 and connected.It can be imported through the first salt chamber inlet 107 The absorbing liquid that desulfurizing tower 1 is discharged.There can be at least one first alkali room entrance 108 and at least one first in first alkali room 31 Alkali room outlet 109.Water can be imported when device driving enables through the first alkali room entrance 108.In the first cathode 101 and the first sun Under the action of the electric field that pole 105 is formed, OH in the first alkali room 31^-Ion enrichment, H in the first salt room 32⁺Ion enrichment, the first salt Na in room 32⁺Ion enters the first alkali room 31 and and OH through the first cation-exchange membrane 103^-Ion forms NaOH aqueous solutions, The NaOH aqueous solutions of formation are through 109 export of the first alkali room outlet.First alkali room outlet 109 can enter with the absorbent of desulfurizing tower 1 Mouth connection.NaOH aqueous solutions derived from first alkali room outlet 109 can be as absorbent for the desulfurization process in desulfurizing tower 1. HSO in first salt room 32₃ ^-And SO₃ ^2-With H⁺Ion forms H₂SO₃, can be with H₂SO₄Together, 106 are exported by the first salt room Discharge.First salt room outlet 106 can be connected with the entrance of desorber 4.H is contained by 106 discharge of the first salt room outlet₂SO₃ And H₂SO₄Material desorbed in desorber 4, release contain SO₂Stripping gas.There is gas vent and liquid on desorber 4 Outlet.What is discharged after desorption contains SO₂Stripping gas discharged through gas vent.By the SO in the stripping gas of discharge₂Oxidized conversion For SO₃.The SO of release₂Remaining material is discharged as stripping liquid through the liquid outlet on desorber 4 afterwards.Containing residual in stripping liquid The H of amount₂SO₃And H₂SO₄Aqueous solution.The stripping liquid is split into the first stripping liquid and the second stripping liquid, with the described first desorption The SO that liquid sorption enhanced obtains₃To generate H₂SO₄；The second stripping liquid reuse is enriched with H into the electrodialysis plant₂SO₃； And amount of makeup water is no less than by SO into the electrodialysis plant₃It is converted into the water that the concentrated sulfuric acid is consumed.Wherein it is preferred to The second stripping liquid reuse is directed into the first salt room 32 of the electrodialysis plant.Wherein, to the electrodialysis The water of addition is supplemented in device can import in the first salt room 32.

Wherein, the two compartments bipolar membrane electrodialysis device 301, which can have, is arranged at the first cathode 101 and the first anode Multigroup two compartments bipolar membrane electrodialysis film pair between 105；And two group of two adjacent compartment bipolar membrane electrodialysis film centering, it is previous Organize first pair of the second Bipolar Membrane of two compartment bipolar membrane electrodialysis films pair as two compartment bipolar membrane electrodialysis film pair of later group Pole film.For example, two bipolar membrane electrodialysis films pair as shown in Figure 2, the bipolar membrane electrodialysis film on the left of Fig. 2 is to including first pair Pole film 102, the first cation-exchange membrane 103 and the second Bipolar Membrane 104, the first Bipolar Membrane 102 and the first cation-exchange membrane 103 Between form the first alkali room 31, the first salt room 32 is formed between the second Bipolar Membrane 104 and the first cation-exchange membrane 103；Fig. 2 is right The bipolar membrane electrodialysis film of side is to including the second Bipolar Membrane 104, cation-exchange membrane 113 and Bipolar Membrane 114, the second Bipolar Membrane Another the first alkali room 31, shape between Bipolar Membrane 114 and cation-exchange membrane 113 are formed between 104 and cation-exchange membrane 113 Into another the first salt room 32.

Wherein, pole room, 105 and second pole film of the first anode can be formed between the first cathode 101 and the first pole film 130 Pole room can also be formed between 131.Contain pole liquid in pole room.Such as pole liquid can be containing Na₂SO₄Aqueous solution (concentration can be with For 2-3 weight % or so).Wherein, between the first pole film 130 and two compartment bipolar membrane electrodialysis films pair (such as the first pole film 130 Between the first Bipolar Membrane 102) another the first salt room 32 can be formed.Wherein, the second pole film 131 and two compartment Bipolar Membranes electricity (such as between the second pole film 131 and Bipolar Membrane 114) can form another first alkali room 31 between dialyser pair.

Wherein, in above-mentioned preferred embodiment, the Na in absorbing liquid⁺Can by the first cation-exchange membrane 103 by Enter in the first salt room 32 in first alkali room 31.Electrodialytic condition can be controlled to cause in the first salt room 32 Na⁺Concentration maintain below 300ppm, can also the Matter Transfer in the first salt room 32 be repeatedly subjected to electrodialysis, with drop Low Na⁺Concentration.

Another preferred embodiment according to the present invention, with reference to figure 3 and Fig. 4, the bipolar membrane electrodialysis device includes Two compartment bipolar membrane electrodialysis devices 302；The two compartments bipolar membrane electrodialysis device 302, which has, is arranged at the first cathode 101 and the Two compartment bipolar membrane electrodialysis film pair of at least one set between one anode 105, the two compartments bipolar membrane electrodialysis film is to including First Bipolar Membrane 102, the first anion-exchange membrane 140 and the second Bipolar Membrane 104, the first Bipolar Membrane 102 and the first anion are handed over It changes between film 140 and forms the second salt room 33, the first sour room is formed between the second Bipolar Membrane 104 and the first anion-exchange membrane 140 34；Wherein, carrying out the electrodialytic step includes：The absorbing liquid is passed through in two compartment bipolar membrane electrodialysis devices 302 Second salt room 33 carries out electrodialysis, obtains can continue to absorb SO in the second salt room 33₂The first dialysate, described It obtains being enriched H in first sour room 34₂SO₃The second dialysate.Wherein it is preferred to the second stripping liquid reuse is directed into In first sour room 34 of the electrodialysis plant.Wherein, the water of addition is supplemented into the electrodialysis plant to be imported In first sour room 34.

Wherein, the second salt chamber inlet 138 can be exported with the absorbing liquid of desulfurizing tower 1 and connected.It can be through the second salt chamber inlet 138 import the absorbing liquid that desulfurizing tower 1 is discharged.At least one second saline solution outlet is provided on second salt room 33, the second saline solution goes out Mouth can be that the second salt room exports 139.When electrodialysis starts, water can be imported through the first sour room entrance 137.In the first cathode 101 and the first anode 105 formed electric field under the action of, OH in the second salt room 33^-Ion enrichment, H in the first sour room 34⁺、 HSO₃ ^-And SO₃ ^2-Ion enrichment, the NaHSO in the second salt room 33₃And OH^-Ion forms Na₂SO₃Aqueous solution, the Na of formation₂SO₃Water Solution is with NaOH solution through 139 export of the second salt room outlet.Second salt room outlet 139 can be with the absorbent entrance of desulfurizing tower 1 Connection.Contain Na derived from second salt room outlet 139₂SO₃At the desulfurization that can be back in desulfurizing tower 1 with the aqueous solution of NaOH Reason.HSO in first sour room 34₃ ^-And SO₃ ^2-With H⁺Ion forms H₂SO₃, with H₂SO₄Together, 136 rows are exported by the first sour room Go out.First sour room outlet 136 can be connected with the entrance of desorber 4.H is contained by 136 discharge of the first sour room outlet₂SO₃'s Material is desorbed in desorber 4, and release contains SO₂Stripping gas.There is gas vent and liquid outlet on desorber 4.Solution The stripping gas discharged after suction is discharged through gas vent.By the SO in the stripping gas of discharge₂Oxidized be converted into SO₃.Release SO₂Remaining material is discharged as stripping liquid through the liquid outlet on desorber 4 afterwards.H containing residual in stripping liquid₂SO₃With H₂SO₄Aqueous solution.The stripping liquid is split into the first stripping liquid and the second stripping liquid, with the first stripping liquid sorption enhanced Obtained SO₃To generate H₂SO₄；The second stripping liquid reuse is enriched with H into the electrodialysis plant₂SO₃；And to described It is supplemented in electrodialysis plant by SO₃It is converted into the water that the concentrated sulfuric acid is consumed.

Wherein, the two compartments bipolar membrane electrodialysis device 302, which can have, is arranged at the first cathode 101 and the first anode Multigroup two compartments bipolar membrane electrodialysis film pair between 105；And two group of two adjacent compartment bipolar membrane electrodialysis film centering, it is previous Organize first pair of the second Bipolar Membrane of two compartment bipolar membrane electrodialysis films pair as two compartment bipolar membrane electrodialysis film pair of later group Pole film.For example, two bipolar membrane electrodialysis films pair as shown in Figure 4, the bipolar membrane electrodialysis film on the left of Fig. 4 is to including first pair Pole film 102, the first anion-exchange membrane 140 and the second Bipolar Membrane 104, the first Bipolar Membrane 102 and the first anion-exchange membrane 140 Between form the second salt room 33, the first sour room 34 is formed between the second Bipolar Membrane 104 and the first anion-exchange membrane 140；Fig. 4 is right The bipolar membrane electrodialysis film of side is to including the second Bipolar Membrane 104, anion-exchange membrane 141 and Bipolar Membrane 114, the second Bipolar Membrane Another the second salt room 33, shape between Bipolar Membrane 114 and anion-exchange membrane 141 are formed between 104 and anion-exchange membrane 141 Into another the first sour room 34.

Wherein, pole room, 105 and second pole film of the first anode can be formed between the first cathode 101 and the first pole film 130 Pole room can also be formed between 131.Contain pole liquid in pole room.The effect of polar region is exactly to provide direct current to bipolar membrane electrodialysis device Electricity.Such as pole liquid can be containing Na₂SO₄Aqueous solution.Wherein, the first pole film 130 and two compartment bipolar membrane electrodialysis films are to it Between (such as between the first pole film 130 and the first Bipolar Membrane 102) another the first sour room 34 can be formed.Wherein, the second pole film 131 and two between compartment bipolar membrane electrodialysis film pair (such as between the second pole film 131 and Bipolar Membrane 114) other one can be formed A second salt room 33.

Another is preferably carried out mode according to the present invention, with reference to figure 5 and Fig. 6, the bipolar membrane electrodialysis device bag Include three compartment bipolar membrane electrodialysis devices 303；The three compartments bipolar membrane electrodialysis device 303, which has, is arranged at 201 He of the second cathode Three compartment bipolar membrane electrodialysis film pair of at least one set between second plate 206, the three compartments bipolar membrane electrodialysis film is to bag Include the 3rd Bipolar Membrane 202, the second cation-exchange membrane 203, the second anion-exchange membrane 204 and the 4th Bipolar Membrane 205, the 3rd pair The second alkali room 35, the second cation-exchange membrane 203 and anion-exchange membrane are formed between pole film and the second cation-exchange membrane 203 The 3rd salt room 36 is formed between 204, the second sour room 37 is formed between the second anion-exchange membrane 204 and the 4th Bipolar Membrane 205；It will The 3rd salt room 36 that the stripping liquid is passed through in three compartment bipolar membrane electrodialysis devices 5 carries out electrodialysis, in the second sour room 37 To being enriched H₂SO₃The second dialysate, obtain can continue in the second alkali room 35 absorbing SO₂The first dialysate.By described in Stripping liquid splits into the first stripping liquid and the second stripping liquid, the SO obtained with the first stripping liquid sorption enhanced₃With generation H₂SO₄；The second stripping liquid reuse is enriched with H into the electrodialysis plant₂SO₃.Wherein it is possible to it is filled to the electrodialysis Middle supplement water is put, the amount of the water of supplement is no less than by SO₃It is converted into the water that the concentrated sulfuric acid is consumed.Wherein it is preferred to by described Two stripping liquid reuses are directed into second sour room 37 of the electrodialysis plant.

Wherein, the 3rd salt chamber inlet 210 can be exported with the absorbing liquid of desulfurizing tower 1 and connected.It is led through the 3rd salt chamber inlet 210 Enter the absorbing liquid of the discharge of desulfurizing tower 1.When device is driven, it can be imported through the second alkali room entrance 212 and the second sour room entrance 211 Water.Under the action of the electric field formed in the second cathode 201 and second plate 206, OH in the second alkali room 35^-Ion enrichment, second H in sour room 37⁺Ion enrichment, the Na in the 3rd salt room 36⁺Ion enters the second alkali room 35 and and OH^-Ion formation contains NaOH Aqueous solution can continue to absorption SO₂The first dialysate, formation can continue to absorb SO₂The first dialysate through the second alkali 207 export of room outlet.Second alkali room outlet 207 can be connected with the absorbent entrance of desulfurizing tower 1.It leads second alkali room outlet 207 What is gone out can continue to absorption SO₂The first dialysate can be as absorbent for the desulfurization process in desulfurizing tower 1.3rd salt room HSO in 36₃ ^-、SO₃ ^2-And SO₄ ^2-Into the second sour room 37 and and H⁺Ion formation contains H₂SO₃And H₂SO₄Be enriched H₂SO₃ The second dialysate, pass through the second sour room outlet 208 discharge.On 3rd salt room 36 there is the 3rd salt room to export 209, available for arranging The material that goes out in the 3rd salt room 36 is simultaneously recycled into the 3rd salt room 36.

Wherein, the three compartments bipolar membrane electrodialysis device 303, which can have, is arranged at the second cathode 201 and second plate Multigroup three compartments bipolar membrane electrodialysis film pair between 206；And two group of three adjacent compartment bipolar membrane electrodialysis film centering, it is previous Organize the 3rd pair of the 4th Bipolar Membrane of three compartment bipolar membrane electrodialysis films pair as three compartment bipolar membrane electrodialysis film pair of later group Pole film.For example, two bipolar membrane electrodialysis films pair as shown in Figure 5, the bipolar membrane electrodialysis film on the left of Fig. 5 is to including the 3rd pair Pole film 202, the second cation-exchange membrane 203, the second anion-exchange membrane 204 and the 4th Bipolar Membrane 205, the 3rd Bipolar Membrane and the The second alkali room 35 is formed between two cation-exchange membranes 203, between the second cation-exchange membrane 203 and anion-exchange membrane 204 The 3rd salt room 36 is formed, the second sour room 37 is formed between the second anion-exchange membrane 204 and the 4th Bipolar Membrane 205；On the right side of Fig. 5 Bipolar membrane electrodialysis film to including the 4th Bipolar Membrane 205, cation-exchange membrane 223, anion-exchange membrane 224 and Bipolar Membrane 225, The second alkali room 35, cation-exchange membrane 223 and anion exchange are formed between 4th Bipolar Membrane 205 and cation-exchange membrane 223 The 3rd salt room 36 is formed between film 224, the second sour room 37 is formed between anion-exchange membrane 224 and Bipolar Membrane 225.

Wherein, at least one second alkali room outlet 207 can be provided in second alkali room 35；Second sour room 37 On can be provided at least one second sour room outlet 208；The second alkali room outlet 207 and the absorbent entrance of desulfurizing tower 1 Connection, the second sour room outlet 208 are connected with 4 entrance of desorber.

Wherein, pole room, second plate 206 and quadrupole film can be formed between the second cathode 201 and the 3rd pole film 230 Pole room can also be formed between 231.Pole liquid can be contained in pole room.Such as pole liquid can contain Na₂SO₄Aqueous solution.Wherein, (such as between the 3rd pole film 230 and the 3rd Bipolar Membrane 202) can between 3rd pole film 230 and three compartment bipolar membrane electrodialysis films pair To form another the second sour room 37.Wherein, between 231 and three compartment bipolar membrane electrodialysis film pair of quadrupole film (such as the 4th Between pole film 231 and Bipolar Membrane 225) another second alkali room 35 can be formed.

Preferably, it is also associated between the absorbing liquid outlet of the desulfurizing tower 1 and the entrance of the absorbing liquid recovery system Absorbing liquid circulating pump 6.Absorbing liquid circulating pump 6 to desulfurizing tower 1 and/or can inhale the absorbing liquid absorbing liquid pump that desulfurizing tower 1 is discharged Receive liquid recovery system.

Preferably, solid-liquid point is also associated between the absorbing liquid circulating pump 6 and the entrance of the absorbing liquid recovery system From device 2, the absorbing liquid outlet of the desulfurizing tower 1 is connected with the entrance of absorbing liquid circulating pump 6, and the absorbing liquid circulating pump 6 goes out Mouth is connected with the circulating absorption solution entrance of the desulfurizing tower 1 and the entrance of the solid-liquid separator 2；The solid-liquid separator 2 Purified liquor outlet is connected with the absorbing liquid entrance of the desulfurizing tower 1 and the entrance of the absorbing liquid recovery system.It can use described Solid-liquid separator 2 carrys out the solid constituent in separate absorbent liquid.Wherein, the solid-liquid separator 2 can be settling vessel and/or filtering Device.

Preferably, filter 7 and/or liquid drop separator 8 are additionally provided on the exhanst gas outlet of the desulfurizing tower 1.It can make The dust in the flue gas that desulfurizing tower 1 is discharged is removed with the filter 7.It can be de- to remove using the liquid drop separator 8 The drop carried secretly in the flue gas that sulphur tower 1 is discharged.

Wherein, under preferable case, the absorbent contains NaOH and/or Na₂SO₃；By the flow and the absorption that control flue gas The flow of agent so that NaHSO in absorbing liquid₃With Na₂SO₃Molar ratio be (0.1-100):1, more preferably (1-30):1.Its In, theoretically, 1 mole of NaOH can absorb 1 mole of SO₂Obtain 1 mole of NaHSO₃；2 moles of NaOH can absorb 1 Mole SO₂Obtain 1 mole of Na₂SO₃；1 mole of Na₂SO₃1 mole of SO can be absorbed₂Obtain 2 moles of NaHSO₃.Example Such as, for the content of sulfur dioxide is the flue gas of 700-900ppm by volume in FCC flue gases, using 8-12mol/L's In the case that the aqueous solution of NaOH is as absorbent, the flow for controlling flue gas is (40-100) ten thousand m³/ h, the flow of absorbent are 1-20m³/ h, NaHSO in obtained absorbing liquid₃With Na₂SO₃Molar ratio be (7-9):1.

Wherein, under preferable case, the absorbent contains NaOH and/or Na₂SO₃；The content of sodium ion in the absorbent It is preferably 5-15mol/L for 0.2-20mol/L.Wherein, in the absorbent sodium ion source can be NaOH and/or Na₂SO₃.In the present invention, the content of the sodium ion in the absorbent can keep relative constant.

Wherein, under preferable case, by controlling the service condition of bipolar membrane electrodialysis device (including voltage and/or electric osmose Analyse the time), enabling continue to absorb SO₂The first dialysate pH value be higher than 8, preferably more than 10.Wherein it is possible to it is keeping In the case of voltage substantial constant in bipolar membrane electrodialysis device, by adjusting the electrodialysis time, enabling continue to inhale Receive SO₂The first dialysate pH value be more than 8, preferably more than 10.For example, for sulfur dioxide by volume in FCC flue gases Content be 700-900ppm flue gas, in the case where using the aqueous solution of NaOH of 8-12mol/L as absorbent, control The flow of flue gas is (40-60) ten thousand m³/ h, the flow of absorbent is 3-10m³/ h, NaHSO in obtained absorbing liquid₃With Na₂SO₃'s Molar ratio is (7-9):1；Each group of bipolar membrane electrodialysis film is to when the voltage of upper application is 2-3V, the electrodialysis time is 5- 60min can continue to absorb SO₂The first dialysate pH value be 10.0-13.5.

Wherein, under preferable case, the condition of desorption causes the H in stripping liquid₂SO₃Content for 0.01-0.4mol/L, solution SO in air-breathing₂Content is 7-99.9 volumes %.Wherein, desorber can be vacuum column.For example, it is enriched H₂SO₃Second ooze Analyse H in liquid₂SO₃Content for 0.5-1.25mol/L, the tower top temperature of desorption can be 0-100 DEG C, and column bottom temperature can be 0- 100 DEG C, feeding temperature can be 20-35 DEG C, and the tower top pressure of vacuum stripper is 0.01-1Pa, is obtained under the desorption condition H in stripping liquid₂SO₃Content for 0.01-0.04mol/L, the SO in stripping gas₂Content is 7-97 volumes %.

In the present invention, the absorbent is aqueous solution, and contains NaOH, Na₂SO₃, in ammonium hydroxide and water-soluble organic amine extremely Few one kind.Preferably, the absorbent is aqueous solution, and contains NaOH and/or Na₂SO₃.Another as the present invention is implemented Mode, the absorbent is aqueous solution, and contains ammonium hydroxide；Wherein, the concentration of ammonium hydroxide can be 1-10 weight %.As the present invention Another embodiment, the absorbent is aqueous solution, and contains water-soluble organic amine；Wherein, water-soluble organic amine is dense Degree can be 1-50 weight %.Wherein, water-soluble organic amine can include but is not limited to trimethylamine, triethylamine, ethylenediamine and two At least one of methylformamide.

Wherein it is preferred to contact of the sulfur-containing smoke gas with absorbent carries out in desulfurizing tower 1.In order to further improve desulfurization The SO of tower 1₂Absorption efficiency, wherein, it is highly preferred that the lower part of the desulfurizing tower 1 has smoke inlet, the desulfurizing tower 1 Top there is exhanst gas outlet, at least one spraying layer and at least one is disposed in the desulfurizing tower 1 from top to bottom Sieve tray, and the spraying layer and the sieve tray are arranged between the smoke inlet and the exhanst gas outlet, wherein, it is described Spraying layer in be provided with spray element with absorbent pipeline connection, the spray element is included by inorganic porous agglomerated material The atomizer of formation；The absorbent sprays from the atomizer and with being flowed from bottom to up in the desulfurizing tower 1 The sulfur-containing smoke gas contact.

Wherein, the smoke inlet can import sulfur-containing smoke gas in the desulfurizing tower 1, and the exhanst gas outlet can will take off Flue gas after sulphuring treatment is exported from the desulfurizing tower 1, and the flue gas can from bottom to up flow in the desulfurizing tower 1, The spraying layer 2 can spray the absorbent for absorbing the oxysulfide in flue gas, and the sieve tray 3 can slow down the absorbent Flow velocity with the flue gas is so that the absorbent can come into full contact with the flue gas.Pressure on the absorbent is applied to Under the driving of power, can partly or entirely pass through on the atomizer formed by inorganic porous agglomerated material in the absorbent Micropore spray and be atomized.

Wherein, the inorganic porous agglomerated material can be the various inorganic porous burnings for filtering that can be commercially available Tie material；Preferably, the average pore size of the inorganic porous agglomerated material is 1nm-50 μm, porosity 10-70%.

Wherein, it is further preferred that the average pore size of the inorganic porous agglomerated material is 50nm-2 μm.At this preferably In the case of, fume desulfurizing tower of the invention can obtain more good atomizing effect at lower pressures.

Wherein, the material of the inorganic porous agglomerated material does not require particularly, such as the inorganic porous sintering material Material includes at least one of porous metals agglomerated material, porous ceramic film material and porous silicon carbide.Porous ceramic film material can be with Including at least one of silicon oxide ceramics film, alumina ceramic membrane, zirconia ceramics film and titanium oxide ceramics film, in order to reduce Corrosion of the absorbent to ceramic membrane, it is preferable that the porous ceramic film material includes alumina ceramic membrane, zirconia ceramics film and oxygen Change at least one of titanium ceramic membrane.

Wherein, the inorganic porous agglomerated material can be individual layer or multilayer, such as the inorganic porous sintering Material can include porous matrix and key-course, and the average pore size of the key-course is more than the average pore size of the porous matrix.

Wherein, the specification of the porous matrix does not require particularly, as long as the ceramic membrane, example can be supported Such as, the average pore size of the porous matrix can be 100nm-10 μm, and thickness can be 0.5-10mm, and porosity can be 40- 60%.

Wherein, the material of the porous matrix can be conventional selection, it is preferable that the tubular porous matrix is ceramics Porous matrix and/or stainless steel porous matrix.The selection of the material or routine of the key-course, such as the key-course It can be ceramic membrane.

Wherein, the porous matrix can be uniform one layer, it is preferable that the porous matrix includes supporting layer and setting Transition zone between the supporting layer and the key-course, the bore dia of the supporting layer are more than the Kong Zhi of the transition zone Footpath.The transition zone can reduce the hole plug degree of the key-course, and extend the electrodeless porous sintered material uses the longevity Life.Wherein, as a kind of embodiment, it is attached with transition zone on the outer wall of the supporting layer, it is attached on the outer wall of the transition zone Key-course, the absorbent first passes through the supporting layer, using the transition zone, is then sprayed by the key-course Atomization.Wherein, alternatively embodiment, is attached with transition zone on the inner wall of the supporting layer, the transition zone it is interior Key-course is attached on wall, the absorbent first passes through the key-course, using the transition zone, then by the support Layer sprays atomization.

Wherein it is preferred to the bore dia of the supporting layer is 200nm-10 μm, thickness 0.5-10mm, porosity 40- 60%；The bore dia of the transition zone is 100nm-5 μm, and thickness is 20-50 μm, porosity 40-60%.

Wherein, the quantity of the spraying layer and the sieve tray does not require particularly, can be respectively one or more, Preferably, the spraying layer is at least two, and the sieve tray is at least two, and the spraying layer and sieve tray alternating It is arranged in the desulfurizing tower 1.

Wherein it is preferred to deduster is also provided between the exhanst gas outlet and the spraying layer from top to down and is removed Day with fog；Bottom of towe below the smoke inlet is additionally provided with absorption liquid pool, by having between the absorption liquid pool and the spraying layer The pipeline for having absorbing liquid circulating pump connects.

Wherein, the deduster can remove the solid dust in the flue gas, and the demister can be removed in flue gas The mist of entrainment.The deduster can be bag-type dust collector and/or membrane tube filter device.The demister can be silk screen Demister.It is described absorb liquid pool can be collected in the desulfurizing tower 1 contacted with absorbent with sulfur-containing smoke gas after obtained absorption Liquid.Absorbing liquid can be cycled and is pumped into again in the pipeline of the spraying layer by the absorbing liquid circulating pump, and the spray stated described in warp Spray element in layer sprays atomization.

Wherein, it is described spray element can all atomizers formed by inorganic porous agglomerated material, can also portion It is divided into the atomizer formed by inorganic porous agglomerated material, rest part is conventional nozzle.

Wherein, in order to mitigate the stopping state of the atomizer formed by inorganic porous agglomerated material, it is preferable that the spray The first dust filter unit for preventing dust into the spray element is provided between leaching element and the absorbent pipeline.

Wherein, in order to mitigate the stopping state of the atomizer formed by inorganic porous agglomerated material, it is highly preferred that described There is the second dust filter unit for preventing dust from entering the circulating pump between circulating pump and the absorption liquid pool.

Wherein, by the SO in the stripping gas₂It is oxidized to SO₃And obtained with the water in first stripping liquid and oxidation SO₃It reacts to generate H₂SO₄Process can in a manner of one turn of one suction, double-absorption, three-conversion three-absorption or non-stationary transformantion into Row.Wherein, one turn of one suction, the double-absorption, the three-conversion three-absorption and the non-stationary transformantion are sulfuric acid preparation fields In conventional use of process.For example, document (Wang Shijuan etc., sulfuric acid conversion process progress summary, learn by Nantong Vocational College Report, in December, 2001) have been disclosed for the process of one turn of one suction, the double-absorption and the three-conversion three-absorption. There is document (Ji Luo armies etc., the application of low-concentration flue gas non-stationary transformantion acid-making process, sulfuric acid industry, 2006 (6), 5-10) Disclose the process of the non-stationary transformantion.Specifically, the process of one turn of one suction is included SO₂Import SO₂Turn Change and once converted in tower, contain SO to what is be converted into₂And SO₃Converted product once absorbed, then will once inhale Tail gas of the remaining gas as Sulphuric acid after receipts；The process of the double conversion double absorption is included SO₂Import SO₂In converter First time conversion is carried out, contains SO to what is be converted into₂And SO₃The first converted product carry out first time absorption, then by first Remaining gas imports SO again after secondary absorption₂It carries out converting for second in converter, remaining gas after first time is absorbed In SO₂It is converted into SO₃, contain SO to what is be converted into₂And SO₃The second converted product carry out second and absorb, then by the Tail gas of the remaining gas as Sulphuric acid after double absorption.The process of the three-conversion three-absorption is included SO₂Import SO₂Turn Change and first time conversion is carried out in tower, contain SO to what is be converted into₂And SO₃The first converted product carry out first time absorption, then Remaining gas imports SO again after first time is absorbed₂It carries out converting for second in converter, it is remaining after first time is absorbed Gas in SO₂It is converted into SO₃, contain SO to what is be converted into₂And SO₃The second converted product carry out second and absorb, so Remaining gas imports SO again after absorbing for second afterwards₂Third time conversion is carried out in converter, is remained after third time is absorbed SO in remaining gas₂It is converted into SO₃, contain SO to what is be converted into₂And SO₃The 3rd converted product carry out third time absorption, Then remaining gas is as the tail gas of Sulphuric acid after third time is absorbed.Wherein, by SO₂It is converted into SO₃Device and condition can Think conventional selection, details are not described herein by the present invention.Wherein, SO is contained by what is be converted into₂And SO₃Converted product carry out The device and condition of absorption can be conventional selection, and details are not described herein by the present invention.Wherein, the tail gas of above-mentioned Sulphuric acid can be with A part of return to step (a) as sulfur-containing smoke gas carries out the contact with absorbent.

Wherein, the stripping gas is being oxidized to SO₃Before, the stripping gas can be dried to processing to remove State the water carried secretly in stripping gas.

Wherein it is preferred to method of the invention further includes：It is aoxidized with the concentrated sulfuric acid absorption that concentration is 97-99 weight % The SO arrived₃, obtain the first sulfuric acid；The stripping gas is dried with the concentrated sulfuric acid that concentration is 97-99 weight %, to absorb The water in stripping gas is stated, obtains the second sulfuric acid；First sulfuric acid, second sulfuric acid and first stripping liquid are mixed, The condition of mixing so that the concentration of sulfuric acid in the material being mixed to get is 97-99 weight %.

Wherein, first sulfuric acid can be oleum, you can with for SO₃Mass fraction be 1-66 weight % sulphur Acid, the concentration of second sulfuric acid can be less than 97 weight %, it is preferable that the amount and the solution of the water in first stripping liquid It is 97-99 weight % that the summation of the amount of water in air-breathing, which enables to the concentration of the 3rd sulfuric acid,.

Wherein it is preferred to method of the invention further includes：Water is added in into the electrodialysis plant, adds in the amount of water not Less than the summation of the amount of the water in the amount and the stripping gas of the water in first stripping liquid.

Wherein it is preferred to the SO obtained with the water sorption enhanced in the water and the stripping gas in first stripping liquid₃ It reacts to generate H₂SO₄During the exhaust gas that generates carried out and absorbent as a part of return to step (a) of sulfur-containing smoke gas Contact.In the preferred embodiment, preparing the exhaust gas in sulfuric acid stage can return for desulfurization, so as to reduce further sulphur The discharge capacity of oxide.

Wherein it is preferred to which the stripping gas discharged through the gas vent of desorber 4 is imported in drier 5, removed with dry The moisture carried secretly in stripping gas, drier used can be the concentrated sulfuric acid of 97-99 weight % in drier 5,97-99 weight % The concentrated sulfuric acid can be imported through pipeline 583 in the drier 5, after the moisture carried secretly in absorbing the stripping gas, obtain Second sulfuric acid is exported through pipeline 585.

Wherein it is possible to dry stripping gas is successively heated to 400- by the second heat exchanger 52 and First Heat Exchanger 51 440 DEG C, to reach SO₂It is converted into SO₃Reaction temperature, be then introduced into SO₂It is oxidized in converter 53 containing SO₃One The gas that once converts is directed into the first sulfuric acid absorption tower 56 through the second heat exchanger 52 with the concentrated sulfuric acid (concentration by secondary conversion gas 97-99 weight %, preferably 98 weight %) it absorbs, it generates the first sulfuric acid and first and absorbs residual gas.Wherein, the second heat exchanger 52 and First Heat Exchanger 51 be respectively used to SO₂It is converted into SO₃When the heat that generates for the stripping gas after heat drying.

Wherein it is possible to the first absorption residual gas is successively heated to by the 4th heat exchanger 55 and the 3rd heat exchanger 54 400-440 DEG C, to reach SO₂It is converted into SO₃Reaction temperature, be then introduced into SO₂It is oxidized in converter 53 containing SO₃ Secondary conversion gas, the secondary conversion gas is directed into through the 4th heat exchanger 55 in the second sulfuric acid absorption tower 57 and uses the concentrated sulfuric acid (concentration 97-99 weight %, preferably 98 weight %) absorbs, and generates the 3rd sulfuric acid and second and absorbs residual gas.

Wherein it is possible to above-mentioned first sulfuric acid is imported through pipeline 586 in sulfuric acid dilution device 58, by above-mentioned 3rd sulfuric acid through pipe Road 587 is imported in sulfuric acid dilution device 58, second sulfuric acid is imported through pipeline 585 in sulfuric acid dilution device 58, by described first Stripping liquid is imported through pipeline 42 in sulfuric acid dilution device 58.It can be by the amount for the first stripping liquid for controlling importing, to control sulfuric acid Sulfuric acid concentration in diluter 58 is 97-99 weight %, is preferably 98 weight %.97-99 weight % in sulfuric acid dilution device 58 Sulfuric acid can export as finished product sulfuric acid through piping 581, can also be exported through pipeline 582 for dry and SO₃Absorption.Its In, the sulfuric acid for dry 97-99 weight % can be directed into through piping 583 in drier 5, for absorbing SO₃97- The sulfuric acid of 99 weight % can be directed respectively into through piping 584 into the first sulfuric acid absorption tower 56 and the second sulfuric acid absorption tower 57.

Wherein it is possible to the stripping liquid is split by flow divider 41 through the first stripping liquid derived from pipeline 42 and through pipe Derived from road 43 during the second stripping liquid, the ratio between the first stripping liquid and the second stripping liquid can be because in sulfuric acid dilution device 58 Depending on water requirement.

In the present invention, the Bipolar Membrane of two compartment bipolar membrane electrodialysis films pair and three compartment bipolar membrane electrodialysis film centerings, sun Amberplex and anion-exchange membrane can be obtained by buying the film product of commercialization.It such as can be from Zhejiang thousand Autumn environmental protection water process Co., Ltd is commercially available.

The present invention is further described by the following examples.In following embodiment, nitrogen and sulfur dioxide are used Gaseous mixture is tested as the flue gas of simulation, and in the gaseous mixture, by volume, the content of FCC sulfur dioxide in flue gas is 800ppm。

Embodiment 1

With reference to figure 1 and Fig. 2, flue gas enters desulfurizing tower 1 by the smoke inlet 11 of desulfurizing tower 1, with absorbing in desulfurizing tower 1 Agent is contacted, and to obtain desulfurization process, then discharges desulfurizing tower 1 by exhanst gas outlet 12.In the initial period of fume treatment, Absorbent is the sodium hydroxide of 1mol/L.Wherein, the flow for controlling flue gas is 500,000 m³/ h, the flow of absorbent is 4m³/ h, obtains To absorbing liquid in NaHSO₃With Na₂SO₃Molar ratio be 8:1.

Using two compartment bipolar membrane electrodialysis devices 301 as bipolar membrane electrodialysis device, imported through the first salt chamber inlet 107 The absorbing liquid that desulfurizing tower 1 is discharged.In the initial period of fume treatment, water is imported through the first alkali room entrance 108.In the first cathode 101 and the first anode 105 formed electric field under the action of, OH in the first alkali room 31^-Ion enrichment, H in the first salt room 32⁺Ion It is enriched with, the Na in the first salt room 32⁺Ion enters the first alkali room 31 and and OH through the first cation-exchange membrane 103^-Ion is formed NaOH aqueous solutions, formation can continue to absorption SO containing NaOH aqueous solutions₂The first dialysate through the first alkali room export 109 Export.First alkali room outlet 109 is connected with the absorbent entrance of desulfurizing tower 1.It can continue to inhale derived from first alkali room outlet 109 Receive SO₂The first dialysate as absorbent for the desulfurization process in desulfurizing tower 1.HSO in first salt room 32₃ ^-And SO₃ ^2-With H⁺Ion forms H₂SO₃, obtain containing H₂SO₃Be enriched H₂SO₃The second dialysate, be enriched H₂SO₃The second dialysate lead to Cross 106 discharge of the first salt room outlet.Each group of two compartment bipolar membrane electrodialysis films pair in two compartment bipolar membrane electrodialysis devices 301 When the voltage of upper application is 2.5V, the electrodialysis time is 30min, can continue to absorb SO₂The first dialysate pH value for 12, Na in first salt room 32⁺Concentration maintain below 300ppm.

First salt room outlet 106 is connected with the entrance of desorber 4.Pass through being enriched for 106 discharge of the first salt room outlet H₂SO₃The second dialysate desorbed in desorber 4, discharge stripping gas.There is gas vent and liquid outlet on desorber 4. The stripping gas discharged after desorption is discharged through gas vent.The stripping gas of discharge is oxidized to be converted into SO₃.The SO of release₂It is remaining afterwards Material is discharged as stripping liquid through the liquid outlet on desorber 4.The tower top temperature of desorption is 4 DEG C, and column bottom temperature is 95 DEG C, into Material temperature degree is 30 DEG C, and the tower top pressure of vacuum stripper is 0.5Pa, the H in obtained stripping liquid₂SO₃Content be 0.03mol/ L, the SO in stripping gas₂Content is 95 volume %.

The stripping liquid is split into the first stripping liquid and the second stripping liquid, is obtained with the first stripping liquid sorption enhanced SO₃To generate H₂SO₄；The second stripping liquid reuse is enriched with H into the electrodialysis plant₂SO₃；And to the electric osmose It is supplemented in analysis apparatus by SO₃It is converted into the water that the concentrated sulfuric acid is consumed.The second stripping liquid reuse is directed into the electrodialysis In the first salt room 32 of device.Wherein, the water supplemented into the electrodialysis plant is imported in the first salt room 32.

Wherein, the stripping gas discharged through the gas vent of desorber 4 is imported in drier 5, stripping gas is removed with dry The moisture of middle entrainment, drier used is the concentrated sulfuric acid of 98 weight % in drier 5, and the concentrated sulfuric acid of 98 weight % is through pipeline 583 import in the drier 5, after the moisture carried secretly in absorbing the stripping gas, the second sulfuric acid are obtained, through pipeline 585 Export.

Dry stripping gas is successively heated to 420 DEG C by the second heat exchanger 52 and First Heat Exchanger 51, with reach by SO₂It is converted into SO₃Reaction temperature, be then introduced into SO₂It is oxidized in converter 53 containing SO₃Once conversion gas, will described in It once converts gas and is directed into through the second heat exchanger 52 in the first sulfuric acid absorption tower 56 and absorbed with the concentrated sulfuric acid (98 weight % of concentration), it is raw Residual gas is absorbed into the first sulfuric acid and first.Wherein, the second heat exchanger 52 and First Heat Exchanger 51 are respectively used to SO₂Conversion For SO₃When the heat that generates for the stripping gas after heat drying.

First absorption residual gas is successively heated to 420 DEG C by the 4th heat exchanger 55 and the 3rd heat exchanger 54, to reach To by SO₂It is converted into SO₃Reaction temperature, be then introduced into SO₂It is oxidized in converter 53 containing SO₃Secondary conversion gas, will The secondary conversion gas is directed into through the 4th heat exchanger 55 in the second sulfuric acid absorption tower 57 to be inhaled with the concentrated sulfuric acid (98 weight % of concentration) It receives, generates the 3rd sulfuric acid and second and absorb residual gas.

Wherein, above-mentioned first sulfuric acid is imported through pipeline 586 in sulfuric acid dilution device 58, by above-mentioned 3rd sulfuric acid through pipeline 587 import in sulfuric acid dilution device 58, and second sulfuric acid is imported through pipeline 585 in sulfuric acid dilution device 58, described first is solved Imbibition is imported through pipeline 42 in sulfuric acid dilution device 58.By controlling the amount of the first stripping liquid imported, to control sulfuric acid dilution device Sulfuric acid concentration in 58 is 98 weight %.A part in the sulfuric acid of 98 weight % in sulfuric acid dilution device 58 is through piping 581 Finished product sulfuric acid is exported as, another part is through the export of pipeline 582 for dry and SO₃Absorption.Wherein, for 98 dry weights The sulfuric acid of amount % is directed into through piping 583 in drier 5, for absorbing SO₃The sulfuric acid of 98 weight % divide through piping 584 It is not directed into the first sulfuric acid absorption tower 56 and the second sulfuric acid absorption tower 57.

Wherein, the stripping liquid is split by flow divider 41 through the first stripping liquid derived from pipeline 42 and through pipeline 43 During derived second stripping liquid, the ratio between the first stripping liquid and the second stripping liquid is due to the water requirement in sulfuric acid dilution device 58 It is fixed.

Wherein, the second stripping liquid reuse is directed into the first salt room 32 of the electrodialysis plant；Also, to Water is supplemented in one salt room 32, the amount for supplementing water is by SO₃The amount that the concentrated sulfuric acid is consumed is converted into, i.e., in described first stripping liquid Water content.

Embodiment 2

With reference to figure 3 and Fig. 4, flue gas enters desulfurizing tower 1 by the smoke inlet 11 of desulfurizing tower 1, with absorbing in desulfurizing tower 1 Agent is contacted, and to obtain desulfurization process, then discharges desulfurizing tower 1 by exhanst gas outlet 12.In the initial period of fume treatment, Absorbent is the sodium hydroxide of 1mol/L.Wherein, the flow for controlling flue gas is 500,000 m³/ h, the flow of absorbent is 4m³/ h, obtains To absorbing liquid in NaHSO₃With Na₂SO₃Molar ratio be 8:1.

Using two compartment bipolar membrane electrodialysis devices 302 as bipolar membrane electrodialysis device, imported through the second salt chamber inlet 138 The absorbing liquid that desulfurizing tower 1 is discharged.When electrodialysis starts, water is imported through the first sour room entrance 137.In the first cathode 101 and Under the action of the electric field that one anode 105 is formed, OH in the second salt room 33^-Ion enrichment, H in the first sour room 34⁺、HSO₃ ^-And SO₃ ^2- Ion enrichment, formation are enriched H₂SO₃The second dialysate, the NaHSO in the second salt room 33₃And OH^-Ion forms Na₂SO₃Water Solution, formation contain Na₂SO₃Can continue to of aqueous solution and NaOH solution absorbs SO₂The first dialysate exported through the second salt room 139 export.Second salt room outlet 139 is connected with the absorbent entrance of desulfurizing tower 1.Second salt derived from second salt room outlet 139 Liquid is back to the desulfurization process in desulfurizing tower 1.What the first sour room 34 was formed is enriched H₂SO₃The second dialysate, pass through first acid 136 discharge of room outlet.Each group of two compartment bipolar membrane electrodialysis films are to the voltage of upper application in two compartment bipolar membrane electrodialysis devices 3 For 2.5V when, the electrodialysis time be 30min, can continue to absorb SO₂The first dialysate pH value be 12.5.

First sour room outlet 136 is connected with the entrance of desorber 4.Pass through being enriched for 136 discharge of the first sour room outlet H₂SO₃The second dialysate desorbed in desorber 4, discharge stripping gas.There is gas vent and liquid outlet on desorber 4. The stripping gas discharged after desorption is discharged through gas vent.The stripping gas of discharge is oxidized to be converted into SO₃.The SO of release₂It is remaining afterwards Material is stripping liquid, is discharged through the liquid outlet on desorber 4.The tower top temperature of desorption is 3 DEG C, and column bottom temperature is 97 DEG C, into Material temperature degree is 30 DEG C, and the tower top pressure of vacuum stripper is 0.8Pa, the H in obtained stripping liquid₂SO₃Content be 0.03mol/ L, the SO in stripping gas₂Content is 95 volume %.

The stripping liquid is split into the first stripping liquid and the second stripping liquid, is obtained with the first stripping liquid sorption enhanced SO₃To generate H₂SO₄；The second stripping liquid reuse is enriched with H into the electrodialysis plant₂SO₃；And to the electric osmose It is supplemented in analysis apparatus by SO₃It is converted into the water that the concentrated sulfuric acid is consumed.The second stripping liquid reuse is directed into the electrodialysis In first sour room 34 of device.Wherein, the water supplemented into the electrodialysis plant is imported in first sour room 34.

Wherein, the second stripping liquid reuse is directed into first sour room 34 of the electrodialysis plant；Also, to Water is supplemented in one sour room 34, the amount for supplementing water is by SO₃The amount that the concentrated sulfuric acid is consumed is converted into, i.e., in described first stripping liquid Water content.

Embodiment 3

With reference to figure 5 and Fig. 6, flue gas enters desulfurizing tower 1 by the smoke inlet 11 of desulfurizing tower 1, with absorbing in desulfurizing tower 1 Agent is contacted, and to obtain desulfurization process, then discharges desulfurizing tower 1 by exhanst gas outlet 12.In the initial period of fume treatment, Absorbent is the sodium hydroxide of 1mol/L.Wherein, the flow for controlling flue gas is 500,000 m³/ h, the flow of absorbent is 4m³/ h, obtains To absorbing liquid in NaHSO₃With Na₂SO₃Molar ratio be 8:1.

Using three compartment bipolar membrane electrodialysis devices 303 as bipolar membrane electrodialysis device, the 3rd salt chamber inlet 210 and desulfurization The absorbing liquid outlet connection of tower 1.The absorbing liquid of the discharge of desulfurizing tower 1 is imported through the 3rd salt chamber inlet 210.When device is driven, through the Two alkali room entrances 212 and the second sour room entrance 211 import water.In the work for the electric field that the second cathode 201 and second plate 206 are formed Under, OH in the second alkali room 35^-Ion enrichment, H in the second sour room 37⁺Ion enrichment, the Na in the 3rd salt room 36⁺Ion enters Second alkali room 35 and and OH^-Ion is formed can continue to absorption SO containing NaOH aqueous solutions₂The first dialysate, the energy of formation It is enough to continue to absorb SO₂The first dialysate through the second alkali room outlet 207 export.Second alkali room outlet 207 and the absorption of desulfurizing tower 1 Agent entrance connects.It can continue to absorb SO derived from second alkali room outlet 207₂The first dialysate as absorbent be used for desulfurization Desulfurization process in tower 1.HSO in 3rd salt room 36₃ ^-、SO₃ ^2-And SO₄ ^2-Into the second sour room 37 and and H⁺Ion formation contains H₂SO₃And H₂SO₄Be enriched H₂SO₃The second dialysate, pass through the second sour room outlet 208 discharge.Have on 3rd salt room 36 Second salt room outlet 209 available for the material in the 3rd salt room 36 of discharge and is recycled into the 3rd salt room 36.

Second sour room outlet 208 is connected with the entrance of desorber 4.Pass through being enriched for 208 discharge of the second sour room outlet H₂SO₃The second dialysate desorbed in desorber 4, discharge stripping gas.There is gas vent and liquid outlet on desorber 4. The stripping gas discharged after desorption is discharged through gas vent.The stripping gas of discharge is oxidized to be converted into SO₃.The SO of release₂It is remaining afterwards Material is stripping liquid, is discharged through the liquid outlet on desorber 4.The tower top temperature of desorption is 3 DEG C, and column bottom temperature is 97 DEG C, into Material temperature degree is 30 DEG C, and the tower top pressure of vacuum stripper is 0.8Pa, the H in obtained stripping liquid₂SO₃Content be 0.03mol/ L, the SO in stripping gas₂Content is 95 volume %.

The stripping liquid is split into the first stripping liquid and the second stripping liquid, is obtained with the first stripping liquid sorption enhanced SO₃To generate H₂SO₄；The second stripping liquid reuse is enriched with H into the electrodialysis plant₂SO₃；And to the electric osmose It is supplemented in analysis apparatus by SO₃It is converted into the water that the concentrated sulfuric acid is consumed.The second stripping liquid reuse is directed into the electrodialysis In second sour room 37 of device.Wherein, the water supplemented into the electrodialysis plant is imported in second sour room 37.

Wherein, the second stripping liquid reuse is directed into second sour room 37 of the electrodialysis plant；Also, to Water is supplemented in two sour rooms 37, the amount for supplementing water is by SO₃The amount that the concentrated sulfuric acid is consumed is converted into, i.e., in described first stripping liquid Water content.

The preferred embodiment of the present invention has been illustrated in embodiment 1-3, it is seen that the present invention can will be in flue gas SO₂The concentrated sulfuric acid is fully converted into, and can realize no effuent discharge substantially, effectively recycles absorbing liquid.

The preferred embodiment of the present invention is described in detail above in association with attached drawing, still, the present invention is not limited to above-mentioned realities The detail in mode is applied, within the scope of the technical concept of the present invention, a variety of letters can be carried out to technical scheme Monotropic type, these simple variants all belong to the scope of protection of the present invention.

It is further to note that the specific technical features described in the above specific embodiments, in not lance In the case of shield, can be combined by any suitable means, in order to avoid unnecessary repetition, the present invention to it is various can The combination of energy no longer separately illustrates.

In addition, various embodiments of the present invention can be combined randomly, as long as it is without prejudice to originally The thought of invention, it should also be regarded as the disclosure of the present invention.

Claims

A kind of 1. method using the sulfur-containing smoke gas production concentrated sulfuric acid, it is characterised in that：This method comprises the following steps：

(a) sulfur-containing smoke gas with absorbent is contacted, obtains the flue gas after desulfurization and absorbing liquid；The absorbent is water-soluble for alkalescence Liquid；

(b) absorbing liquid is imported into bipolar membrane electrodialysis device and carries out electrodialysis, obtain can continue to absorb SO₂First ooze It analyses liquid and is enriched H₂SO₃The second dialysate；Using the first dialysate reuse as the part or all of and flue gas of absorbent It is contacted；

(c) second dialysate is desorbed, obtain stripping liquid and contains SO₂Stripping gas；

(d) by the SO in the stripping gas₂It is oxidized to SO₃, the stripping liquid is split into the first stripping liquid and the second stripping liquid, The SO that the water in first stripping liquid is made to be obtained with oxidation₃Reaction generation H₂SO₄；By the second stripping liquid reuse to described H is enriched in electrodialysis plant₂SO₃。
2. according to the method described in claim 1, wherein, the bipolar membrane electrodialysis device includes two compartment bipolar membrane electrodialysis Device (301)；The two compartments bipolar membrane electrodialysis device (301) have be arranged at the first cathode (101) and the first anode (105) it Between two compartment bipolar membrane electrodialysis film pair of at least one set, the two compartments bipolar membrane electrodialysis film is to including the first Bipolar Membrane (102), the first cation-exchange membrane (103) and the second Bipolar Membrane (104), the first Bipolar Membrane (102) and the first cation exchange The first alkali room (31) is formed between film (103), is formed between the second Bipolar Membrane (104) and the first cation-exchange membrane (103) One salt room (32)；

Wherein, carrying out the electrodialytic step includes：The absorbing liquid is passed through in two compartment bipolar membrane electrodialysis devices (301) The first salt room (32) carry out electrodialysis, obtain can continue in the first alkali room (31) absorbing SO₂The first dialysate, in institute It states and obtains being enriched H in the first salt room (32)₂SO₃The second dialysate；The second stripping liquid reuse is directed into the electric osmose In the first salt room (32) of analysis apparatus.
3. according to the method described in claim 1, wherein, the bipolar membrane electrodialysis device includes two compartment bipolar membrane electrodialysis Device (302)；The two compartments bipolar membrane electrodialysis device (302) have be arranged at the first cathode (101) and the first anode (105) it Between two compartment bipolar membrane electrodialysis film pair of at least one set, the two compartments bipolar membrane electrodialysis film is to including the first Bipolar Membrane (102), the first anion-exchange membrane (140) and the second Bipolar Membrane (104), the first Bipolar Membrane (102) and the first anion exchange The second salt room (33) is formed between film (140), is formed between the second Bipolar Membrane (104) and the first anion-exchange membrane (140) One sour room (34)；

Wherein, carrying out the electrodialytic step includes：The absorbing liquid is passed through in two compartment bipolar membrane electrodialysis devices (302) The second salt room (33) carry out electrodialysis, obtain can continue in the second salt room (33) absorbing SO₂The first dialysate, It obtains being enriched H in first sour room (34)₂SO₃The second dialysate；The second stripping liquid reuse is directed into described In first sour room (34) of electrodialysis plant.
4. according to the method described in claim 1, wherein, the bipolar membrane electrodialysis device includes three compartment bipolar membrane electrodialysis Device (303)；The three compartments bipolar membrane electrodialysis device (303) have be arranged at the second cathode (201) and second plate (206) it Between three compartment bipolar membrane electrodialysis film pair of at least one set, the three compartments bipolar membrane electrodialysis film is to including the 3rd Bipolar Membrane (202), the second cation-exchange membrane (203), the second anion-exchange membrane (204) and the 4th Bipolar Membrane (205), the 3rd Bipolar Membrane The second alkali room (35), the second cation-exchange membrane (203) and the second anion are formed between the second cation-exchange membrane (203) The 3rd salt room (36), shape between the second anion-exchange membrane (204) and the 4th Bipolar Membrane (205) are formed between exchange membrane (204) Into the second sour room (37)；

Wherein, carrying out the electrodialytic step includes：The absorbing liquid is passed through in three compartment bipolar membrane electrodialysis devices (303) The 3rd salt room (36) carry out electrodialysis, obtain being enriched H in the second sour room (37)₂SO₃The second dialysate, in the second alkali It obtains can continue to absorb SO in room (35)₂The first dialysate；The second stripping liquid reuse is directed into the electrodialysis In second sour room (37) of device.
5. according to the method described in any one in claim 1-4, wherein, the absorbent contains NaOH and/or Na₂SO₃。
6. according to the method described in any one in claim 1-4, wherein, contact of the sulfur-containing smoke gas with absorbent is in desulfurizing tower (1) carried out in, the lower part of the desulfurizing tower (1) has smoke inlet, and the top of the desulfurizing tower (1) goes out with flue gas Mouthful, at least one spraying layer and at least one sieve tray, and the spray are disposed with from top to bottom in the desulfurizing tower (1) Drenching layer and the sieve tray are arranged between the smoke inlet and the exhanst gas outlet, wherein, it is set in the spraying layer There is the spray element with absorbent pipeline connection, the atomization that the spray element includes being formed by inorganic porous agglomerated material is sprayed Mouth；

The absorbent is sprayed from the atomizer and the sulfur-bearing with being flowed from bottom to up in the desulfurizing tower (1) Smoke contacts.
7. according to the method described in any one in claim 1-4, wherein, by the SO in the stripping gas₂It is oxidized to SO₃And The SO obtained with the water in first stripping liquid and oxidation₃It reacts to generate H₂SO₄Process with one turn of one suction, double-absorption, The mode of three-conversion three-absorption or non-stationary transformantion carries out.
8. according to the method described in any one in claim 1-4, wherein, this method further includes：It is 97-99 weights with concentration The concentrated sulfuric acid of amount % absorbs the SO that oxidation obtains₃, obtain the first sulfuric acid；With the concentrated sulfuric acid that concentration is 97-99 weight % to described Stripping gas is dried, and to absorb the water in the stripping gas, obtains the second sulfuric acid；By first sulfuric acid, second sulphur Sour and described first stripping liquid mixing, the condition of mixing so that the concentration of sulfuric acid in the material being mixed to get is 97-99 weight %.
9. according to the method described in any one in claim 1-4, wherein, this method further includes：To the electrodialysis plant Middle addition water, the amount for adding in water are no less than the total of the amount of water in first stripping liquid and the amount of the water in the stripping gas With.
10. according to the method described in any one in claim 1-4, wherein, by the SO in the stripping gas₂It is oxidized to SO₃And The SO obtained with the water in first stripping liquid and oxidation₃It reacts to generate H₂SO₄During the exhaust gas that generates as sulfur-bearing A part of return to step (a) of flue gas carries out the contact with the absorbent.