CN105833698A

CN105833698A - Method for production of concentrated sulfuric acid from sulfur-containing flue gas

Info

Publication number: CN105833698A
Application number: CN201510020879.0A
Authority: CN
Inventors: 谢志成; 刘凯中; 冯晓霞; 王培功
Original assignee: BEIJING ZHONGTIANYUAN 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: 2016-08-10
Anticipated expiration: 2035-01-15
Also published as: CN105833698B

Abstract

The invention provides a method for production of concentrated sulfuric acid from sulfur-containing flue gas. The method comprises the steps of: (a) contacting the sulfur-containing flue gas with an absorbent to obtain desulfurized flue gas and absorption liquid; (b) leading the absorption liquid into a bipolar membrane electrodialysis device to conduct electrodialysis so as to obtain first dialysate able to further absorb SO2 and H2SO3 enriched second dialysate; (c) desorbing the second dialysate to obtain a desorbed solution and SO2 containing desorbed gas; (d) oxidizing SO2 in the desorbed gas into SO3, shunting the desorbed solution into a first desorbed solution and a second desorbed solution, transforming the first desorbed solution to obtain SO3 to produce H2SO4; reusing the second desorbed solution to the electrodialysis device to enrich H2SO3. The method provided by the invention can fully convert the SO2 in the flue gas into concentrated sulfuric acid, also can basically realize zero wastewater discharge, and effectively recovers the desorbed solution.

Description

A kind of method utilizing sulfur-containing smoke gas to produce concentrated sulphuric acid

Technical field

The present invention relates to field of chemical engineering, in particular it relates to a kind of method utilizing sulfur-containing smoke gas to produce concentrated sulphuric acid.

Background technology

Flue gas refers to the mixture of gas and flue dust.Boiler, industrial furnace, thermal power plant, coke oven, cement plant, blast furnace, The operation of the chemical industry equipments such as open hearth, converter, electric furnace and catalytic cracking (FCC) device all can produce substantial amounts of flue gas.Cigarette The air pollutants such as a large amount of sulfur and nitrogen oxides contained in gas bring series of environmental problems.Reduce containing sulfur oxygen The discharge of the air pollutants such as compound and nitrogen oxides is the task of top priority of protection environment.Such as standard GB/T 13271-91 " emission standard of air pollutants for boilers ", GB9078-1996 " industrial furnace atmosphere pollutants emission standards ", GB13223-1996 " fossil-fuel power plant atmospheric pollutant emission standard ", GB16171-1996 " coke oven Air Pollutant Emission Standard " and GB4915-1996 " Airborne Pollutants from Cement Plant discharge standard " all define the discharge mark of pollutant in flue gas Accurate.Therefore, it is necessary to after flue gas is carried out desulphurization and denitration and dust removal process, just can discharge.

In the flue gas desulfurization technique of commercial Application, wet desulphurization is the most the most frequently used and one of more ripe method.Often FCC regenerated flue gas absorption process have the WGS wet scrubbing of EXXON company, the THIOPAQ of Uop Inc. Biotechnology, the EDV wet scrubbing technology etc. of Belco company.The wherein EDV wet process of FGD skill of Belco company Art has become industrial gas purification and SO₂One of main method reclaimed.Commercial Application, EDV is started from 1994 Wet Flue Gas Desulfurization Technology just demonstrates operability and the reliability of excellence.So far, join more than 90 set catalytic cracking units Having overlapped EDV facility, maximum of which production capacity is 5Mt/a.But, the maximum that EDV Wet Flue Gas Desulfurization Technology exists is asked Topic is that this technology can consume a large amount of water and NaOH as absorbing liquid, and with the SO in flue gas₂After reaction, oxidized It is changed into substantial amounts of sodium sulfate salt solution, thus creates the emission problem of a large amount of high-salt wastewater.

Summary of the invention

It is an object of the invention to provide a kind of method, the method can the absorbing liquid that produces of wet desulfurizing and dust collecting system be converted into The alkali liquor of reusable edible, makes full use of SO₂Produce concentrated sulphuric acid, substantially realize no effuent discharge.

It was found by the inventors of the present invention that absorbing liquid is carried out electrodialysis by bipolar membrane electrodialysis device, and take full advantage of It is enriched H₂SO₃The stripping liquid that obtains after desorbing of dialysate in can not the H of Desorption separation₂SO₃With dilute H₂SO₄, will Can not the H of Desorption separation₂SO₃With dilute H₂SO₄Also it is transferred in concentrated sulphuric acid, it is possible to effectively reclaim absorbing liquid and reduce electricity Can consume and realize no effuent discharge, and achieve the tail gas zero-emission of Sulphuric acid workshop section, resulting in the present invention.

To achieve these goals, the invention provides a kind of method utilizing sulfur-containing smoke gas to produce concentrated sulphuric acid, wherein, be somebody's turn to do Method comprises the steps: that sulfur-containing smoke gas is contacted by (a) with absorbent, obtains the flue gas after desulfurization and absorbing liquid；Described Absorbent is alkaline aqueous solution；B described absorbing liquid importing bipolar membrane electrodialysis device is carried out electrodialysis by (), obtaining can Continue to absorb SO₂The first dialysate and be enriched H₂SO₃The second dialysate；Using described first dialysate reuse as Partly or entirely contacting with flue gas of absorbent；C described second dialysate is carried out desorbing by (), obtain stripping liquid and Containing SO₂Stripping gas；D () is by the SO in described stripping gas₂It is oxidized to SO₃, described stripping liquid is split into first Stripping liquid and the second stripping liquid, make the SO that the water in described first stripping liquid obtains with oxidation₃Reaction generates H₂SO₄；Will Described second stripping liquid reuse is enriched with H to described electrodialysis plant₂SO₃。

By technique scheme, the present invention can be by the SO in flue gas₂It is converted into concentrated sulphuric acid fully, the most fully Make use of and be enriched H₂SO₃The stripping liquid that obtains after desorbing of dialysate in can not the H of Desorption separation₂SO₃With dilute H₂SO₄, it is impossible to dilute H of Desorption separation₂SO₄Also it is transferred in concentrated sulphuric acid, it is impossible to the H of Desorption separation₂SO₃Also close And enter oxidation and be transformed in sulphuric acid, and can substantially realize no effuent discharge, effectively reclaim absorbing liquid.

Other features and advantages of the present invention will be described in detail in detailed description of the invention part subsequently.

Accompanying drawing explanation

Accompanying drawing is used to provide a further understanding of the present invention, and constitutes the part of description, concrete with following Embodiment is used for explaining the present invention together, but is not intended that limitation of the present invention.In the accompanying drawings:

The apparatus structure utilizing sulfur-containing smoke gas to produce concentrated sulphuric acid that Fig. 1 is used in a kind of preferred implementation of the present invention shows It is intended to.

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

The apparatus structure utilizing sulfur-containing smoke gas to produce concentrated sulphuric acid that Fig. 3 is used in a kind of preferred implementation of the present invention shows It is intended to.

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

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

The apparatus structure utilizing sulfur-containing smoke gas to produce concentrated sulphuric acid that Fig. 6 is used in a kind of preferred implementation of the present invention shows It is intended to.

Description of reference numerals

1 desulfurizing tower

11 smoke inlet 12 exhanst gas outlets

2 solid-liquid separators

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

303 3 compartment bipolar membrane electrodialysis devices

31 first salt room, alkali rooms 32 first

33 second acid room, salt rooms 34 first

35 second salt room, alkali rooms 36 the 3rd

37 second acid rooms

4 desorbers

41 flow divider 42 pipelines

43 pipelines

5 exsiccator 51 First Heat Exchangers

52 second heat exchanger 53 SO₂Converter

54 the 3rd heat exchanger 55 the 4th heat exchangers

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

58 sulfuric acid dilution devices

581 pipeline 582 pipelines

583 pipeline 584 pipelines

585 pipeline 586 pipelines

6 absorbing liquid circulating pumps

7 filter 8 liquid drop separators

101 first negative electrode 102 first Bipolar Membrane

103 first cation exchange membrane 104 second Bipolar Membrane

105 first anode 106 first salt room outlets

107 first salt chamber inlet 108 first alkali chamber inlets

109 first alkali rooms export 113 cation exchange membranes

114 Bipolar Membrane 130 first pole films

131 second pole film 136 first acid room outlets

137 first acid chamber inlet 138 second salt chamber inlets

139 second salt room outlet 140 first anion exchange membrane

201 second negative electrode 202 the 3rd Bipolar Membrane

203 second cation exchange membrane 204 second anion exchange membrane

205 the 4th Bipolar Membrane 206 second plates

207 second alkali room outlet 208 second acid room outlets

209 the 3rd salt room outlet 210 the 3rd salt chamber inlets

211 second acid chamber inlet 212 second alkali chamber inlets

223 cation exchange membrane 224 anion exchange membrane

225 Bipolar Membrane 230 the 3rd pole films

231 quadrupole films

Detailed description of the invention

Below in conjunction with accompanying drawing, the detailed description of the invention of the present invention is described in detail.It should be appreciated that it is described herein Detailed description of the invention be merely to illustrate and explain the present invention, be not limited to the present invention.

With reference to Fig. 1, Fig. 2, Fig. 3, Fig. 4, Fig. 5 and Fig. 6, the invention provides one and utilize sulfur-containing smoke gas production dense The method of sulphuric acid, the method may be used for the desulfurization of various sulfur-containing smoke gas in chemical field and processes, and described sulfur-containing smoke gas includes But it is not limited to by boiler, industrial furnace, thermal power plant, coke oven, cement plant, blast furnace, open hearth, converter, electric furnace and urges Change the sulfur-containing smoke gas that the chemical industry equipments such as cracking (FCC) device produce.In described sulfur-containing smoke gas, by volume, titanium dioxide The content of sulfur can be 500-3000ppm.

The method utilizing sulfur-containing smoke gas to produce concentrated sulphuric acid provided according to the present invention, wherein, the method comprises the steps: A sulfur-containing smoke gas is contacted by () with absorbent, obtain the flue gas after desulfurization and absorbing liquid；Described absorbent is alkaline aqueous solution； B described absorbing liquid importing bipolar membrane electrodialysis device is carried out electrodialysis by (), obtain can continue to absorb SO₂First ooze Analyse liquid and be enriched H₂SO₃The second dialysate；Using described first dialysate reuse as absorbent partly or entirely with Flue gas contacts；C described second dialysate is carried out desorbing by (), obtain stripping liquid and containing SO₂Stripping gas；(d) By the SO in described stripping gas₂It is oxidized to SO₃, described stripping liquid is split into the first stripping liquid and the second stripping liquid, makes The SO that water in described first stripping liquid obtains with oxidation₃Reaction generates H₂SO₄；By described second stripping liquid reuse to institute State enrichment H in electrodialysis plant₂SO₃。

Wherein, described sulfur-containing smoke gas can enter desulfurizing tower 1 through the smoke inlet 11 of desulfurizing tower 1, in desulfurizing tower 1 Contact with absorbent, to obtain desulfurization process, then discharge desulfurizing tower 1 through exhanst gas outlet 12.Wherein, described Desulfurization processes and can individually carry out in desulfurizing tower 1, it is also possible to carry out with the process of denitration and/or dedusting simultaneously.

Wherein, the particularly requirement of the type of described desulfurizing tower 1, as long as contacting of flue gas and absorbent can be completed, Include but not limited to plate column, bubble absorbing tower, stirring bubble absorbing tower, ejector, Venturi tube, spray tower, filler At least one in absorption tower and film-falling absorption tower.

Wherein, on described desulfurizing tower 1, connection has the absorbing liquid recovery system including described bipolar membrane electrodialysis device.

Wherein, described absorbent is the pH value aqueous solution in alkalescence, and its pH value can be more than 8.Described absorbent Can carry out dissolved sulfur dioxide by water, described absorbent can also increase the suction to sulfur dioxide by alkalescence effective ingredient Receipts amount.Described alkalescence effective ingredient includes but not limited to NaOH, Na₂SO₃, in ammonia and water-soluble organic amine at least A kind of.

Wherein, described absorbent can be the aqueous solution containing NaOH；Or, described absorbent can also be for containing Na₂SO₃Aqueous solution；Or, described absorbent can be not only to contain NaOH but also contain Na₂SO₃Aqueous solution. Described absorbent enter after desulfurizing tower 1 with smoke contacts, the oxysulfide in flue gas is absorbed by absorbent, after contact Absorbent is converted into absorbing liquid and discharges through absorbing liquid outlet.Containing NaHSO in the absorbing liquid discharged₃、Na₂SO₃With Na₂SO₄, by the recycling of absorbing liquid recovery system, it is converted into absorbent and is recycled.Wherein, Bipolar Membrane Electrodialyzer may be used for the NaHSO in the absorbing liquid that will discharge₃And Na₂SO₃It is separated into NaOH and H₂SO₃.Bipolar EDBM device can be used for the NaHSO in the absorbing liquid that will discharge₃It is separated into NaOH and Na₂SO₃Mixture and H₂SO₃.Desorber 4 may be used for the H discharged by bipolar membrane electrodialysis device₂SO₃With SO₂Formal solution suction go out.

A kind of preferred implementation provided according to the present invention, wherein, described bipolar membrane electrodialysis device includes that two compartments are double Pole EDBM device 301；Described two compartment bipolar membrane electrodialysis devices 301 have and are arranged at first negative electrode 101 and the first anode Least one set two compartment bipolar membrane electrodialysis film pair between 105, described two compartment bipolar membrane electrodialysis films are to including first pair Pole film the 102, first cation exchange membrane 103 and the second Bipolar Membrane 104, the first Bipolar Membrane 102 and the exchange of the first cation Form the first alkali room 31 between film 103, between the second Bipolar Membrane 104 and the first cation exchange membrane 103, form the first salt Room 32；Wherein, carry out described electrodialytic step to include: described absorbing liquid is passed through two compartment bipolar membrane electrodialysis devices 301 In the first salt room 32 carry out electrodialysis, obtain can continue in the first alkali room 31 absorbing SO₂The first dialysate, Described first salt room 32 obtains being enriched H₂SO₃The second dialysate.

Wherein, the first salt room 32 can have at least one the first salt chamber inlet 107 and at least one first salt room goes out Mouth 106.First salt chamber inlet 107 can export with the absorbing liquid of desulfurizing tower 1 and be connected.Can be through the first salt chamber inlet 107 Import the absorbing liquid that desulfurizing tower 1 is discharged.At least one first alkali chamber inlet 108 and at least can be had on first alkali room 31 One the first alkali room outlet 109.Water can be imported through the first alkali chamber inlet 108 when device is driven and enabled.At the first negative electrode 101 and the first anode 105 formed electric field effect under, OH in the first alkali room 31^-Ion enrichment, the first salt room 32 Middle H⁺Ion enrichment, the Na in the first salt room 32⁺Ion enters the first alkali room 31 through the first cation exchange membrane 103 And and OH^-Ion forms NaOH aqueous solution, and the NaOH aqueous solution of formation exports 109 derivation through the first alkali room.First Alkali room outlet 109 can be connected with the absorbent entrance of desulfurizing tower 1.The NaOH of the first alkali room outlet 109 derivation is water-soluble Liquid can process as absorbent desulfurization in desulfurizing tower 1.HSO in first salt room 32₃ ^-And SO₃ ^2-With H⁺From Son forms H₂SO₃, can be with H₂SO₄Together, by the first salt room outlet 106 discharge.First salt room outlet 106 can It is connected with the entrance with desorber 4.By first salt room outlet 106 discharge containing H₂SO₃And H₂SO₄Material exist Desorber 4 obtains desorbing, and release is containing SO₂Stripping gas.There is on desorber 4 gas outlet and liquid outlet.Solve After suction release containing SO₂Stripping gas through gas outlet discharge.SO in the stripping gas that will discharge₂Oxidized it is converted into SO₃.The SO of release₂Rear remaining material is discharged as stripping liquid liquid outlet on desorber 4.Stripping liquid contains The H of residual₂SO₃And H₂SO₄Aqueous solution.Described stripping liquid is split into the first stripping liquid and the second stripping liquid, with described The SO that first stripping liquid sorption enhanced obtains₃To generate H₂SO₄；Described second stripping liquid reuse to described electrodialysis is filled Put middle enrichment H₂SO₃；And amount of makeup water is no less than by SO in described electrodialysis plant₃It is converted into concentrated sulphuric acid to be consumed Water.Wherein it is preferred to, described second stripping liquid reuse is directed into the described first salt room 32 of described electrodialysis plant In.Wherein, in described electrodialysis plant, supplement the water added can import in described first salt room 32.

Wherein, described two compartment bipolar membrane electrodialysis devices 301 can have and are arranged at the first negative electrode 101 and the first anode 105 Between many groups of two compartment bipolar membrane electrodialysis films pair；And two group of two adjacent compartment bipolar membrane electrodialysis film centering, previous Organize the second Bipolar Membrane of two compartment bipolar membrane electrodialysis films pair as first pair of later group two compartment bipolar membrane electrodialysis film pair Pole film.Such as, 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 Bipolar Membrane the 102, first cation exchange membrane 103 and the second Bipolar Membrane 104, the first Bipolar Membrane 102 and the first sun from Form the first alkali room 31 between proton exchange 103, formed between the second Bipolar Membrane 104 and the first cation exchange membrane 103 First salt room 32；Bipolar membrane electrodialysis film on the right side of Fig. 2 is to including the second Bipolar Membrane 104, cation exchange membrane 113 and Bipolar Membrane 114, forms another the first alkali room 31, Bipolar Membrane between the second Bipolar Membrane 104 and cation exchange membrane 113 Another the first salt room 32 is formed between 114 and cation exchange membrane 113.

Wherein, room, pole, the first anode 105 and the second pole film can be formed between the first negative electrode 101 and the first pole film 130 Room, pole can also be formed between 131.Containing pole liquid in room, pole.Such as pole liquid can be containing Na₂SO₄Aqueous solution (dense Degree can be about 2-3 weight %).Wherein, the first pole film 130 and two compartment bipolar membrane electrodialysis films between (such as Between first pole film 130 and the first Bipolar Membrane 102) another the first salt room 32 can be formed.Wherein, the second pole film 131 And two compartment bipolar membrane electrodialysis films between (between the such as second pole film 131 and Bipolar Membrane 114) can be formed additionally One the first alkali room 31.

Wherein, the Na in above-mentioned preferred implementation, in absorbing liquid⁺Can by the first cation exchange membrane 103 by Described first salt room 32 enters in described first alkali room 31.Electrodialytic condition can be controlled and make described first salt room Na in 32⁺Concentration maintain below 300ppm, it is also possible to the Matter Transfer in the first salt room 32 is repeatedly carried out electricity Dialysis, to reduce Na⁺Concentration.

According to another preferred embodiment of the present invention, with reference to Fig. 3 and Fig. 4, described bipolar membrane electrodialysis device includes Two compartment bipolar membrane electrodialysis devices 302；Described two compartment bipolar membrane electrodialysis devices 302 have and are arranged at the first negative electrode 101 And the least one set two compartment bipolar membrane electrodialysis film pair between the first anode 105, described two compartment bipolar membrane electrodialysis films To including the first Bipolar Membrane the 102, first anion exchange membrane 140 and the second Bipolar Membrane 104, the first Bipolar Membrane 102 and Formed between one anion exchange membrane 140 second salt room 33, the second Bipolar Membrane 104 and the first anion exchange membrane 140 it Between formed first acid room 34；Wherein, carry out described electrodialytic step to include: described absorbing liquid is passed through two compartments bipolar The second salt room 33 in EDBM device 302 carries out electrodialysis, obtains can continue to absorb in described second salt room 33 SO₂The first dialysate, described first acid room 34 in obtain being enriched H₂SO₃The second dialysate.Wherein, preferably Ground, is directed into described second stripping liquid reuse in the described first acid room 34 of described electrodialysis plant.Wherein, to described Electrodialysis plant supplements the water added can import in described first acid room 34.

Wherein, the second salt chamber inlet 138 can export with the absorbing liquid of desulfurizing tower 1 and be connected.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, the second salt it is provided with on second salt room 33 Liquid outlet can be the second salt room outlet 139.When electrodialysis starts, water can be imported through the first acid chamber inlet 137.? Under the effect of the electric field that the first negative electrode 101 and the first anode 105 are formed, OH in the second salt room 33^-Ion enrichment, first H in acid room 34⁺、HSO₃ ^-And SO₃ ^2-Ion enrichment, the NaHSO in the second salt room 33₃And OH^-Ion forms Na₂SO₃ Aqueous solution, the Na of formation₂SO₃Aqueous solution exports 139 derivation with NaOH solution through the second salt room.Second salt room outlet 139 can be connected with the absorbent entrance of desulfurizing tower 1.Second salt room outlet 139 derivation containing Na₂SO₃And NaOH The desulfurization that can be back in desulfurizing tower 1 of aqueous solution process.HSO in first acid room 34₃ ^-And SO₃ ^2-With H⁺Ion Form H₂SO₃, with H₂SO₄Together, by the first acid room outlet 136 discharge.First acid room outlet 136 can be with solution The entrance inhaling tower 4 is connected.By first acid room outlet 136 discharge containing H₂SO₃Material solved at desorber 4 Inhaling, release is containing SO₂Stripping gas.There is on desorber 4 gas outlet and liquid outlet.The desorbing of release after desorbing Gas is discharged through gas outlet.SO in the stripping gas that will discharge₂Oxidized be converted into SO₃.The SO of release₂Rear residue Material discharge as stripping liquid liquid outlet on desorber 4.Stripping liquid contains the H of residual₂SO₃And H₂SO₄ Aqueous solution.Described stripping liquid is split into the first stripping liquid and the second stripping liquid, obtains with described first stripping liquid sorption enhanced The SO arrived₃To generate H₂SO₄；Described second stripping liquid reuse to described electrodialysis plant will be enriched with H₂SO₃；And Supplement SO in described electrodialysis plant₃It is converted into the water that concentrated sulphuric acid is consumed.

Wherein, described two compartment bipolar membrane electrodialysis devices 302 can have and are arranged at the first negative electrode 101 and the first anode 105 Between many groups of two compartment bipolar membrane electrodialysis films pair；And two group of two adjacent compartment bipolar membrane electrodialysis film centering, previous Organize the second Bipolar Membrane of two compartment bipolar membrane electrodialysis films pair as first pair of later group two compartment bipolar membrane electrodialysis film pair Pole film.Such as, 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 Bipolar Membrane the 102, first anion exchange membrane 140 and the second Bipolar Membrane 104, the first Bipolar Membrane 102 and first the moon from Form the second salt room 33 between proton exchange 140, formed between the second Bipolar Membrane 104 and the first anion exchange membrane 140 First acid room 34；Bipolar membrane electrodialysis film on the right side of Fig. 4 is to including the second Bipolar Membrane 104, anion exchange membrane 141 and Bipolar Membrane 114, forms another the second salt room 33, Bipolar Membrane between the second Bipolar Membrane 104 and anion exchange membrane 141 Another the first acid room 34 is formed between 114 and anion exchange membrane 141.

Wherein, room, pole, the first anode 105 and the second pole film can be formed between the first negative electrode 101 and the first pole film 130 Room, pole can also be formed between 131.Containing pole liquid in room, pole.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 Film between (between the such as first pole film 130 and the first Bipolar Membrane 102) can be formed another first acid room 34.Its In, the second pole film 131 and two compartment bipolar membrane electrodialysis films between (the such as second pole film 131 and Bipolar Membrane 114 it Between) another one the second salt room 33 can be formed.

According to the present invention, another is preferably carried out mode, with reference to Fig. 5 and Fig. 6, described bipolar membrane electrodialysis device bag Include three compartment bipolar membrane electrodialysis devices 303；Described three compartment bipolar membrane electrodialysis devices 303 have and are arranged at the second negative electrode 201 And the least one set three compartment bipolar membrane electrodialysis film pair between second plate 206, described three compartment bipolar membrane electrodialysis films To including the 3rd Bipolar Membrane the 202, second cation exchange membrane the 203, second anion exchange membrane 204 and the 4th Bipolar Membrane 205, Forming the second alkali room 35 between 3rd Bipolar Membrane and the second cation exchange membrane 203, the second cation exchange membrane 203 is with cloudy The 3rd salt room 36, shape between the second anion exchange membrane 204 and the 4th Bipolar Membrane 205 is formed between ion exchange membrane 204 Become the second acid room 37；The 3rd salt room 36 being passed through by described stripping liquid in three compartment bipolar membrane electrodialysis devices 5 carries out electrodialysis, Second acid room 37 obtains being enriched H₂SO₃The second dialysate, obtain can continue in the second alkali room 35 absorbing SO₂The first dialysate.Described stripping liquid is split into the first stripping liquid and the second stripping liquid, with described first stripping liquid The SO that sorption enhanced obtains₃To generate H₂SO₄；Described second stripping liquid reuse to described electrodialysis plant will be enriched with H₂SO₃.Wherein it is possible to supplement water in described electrodialysis plant, the amount of supplementary water is no less than by SO₃It is converted into dense sulfur The water that acid is consumed.Wherein it is preferred to, described second stripping liquid reuse is directed into described the of described electrodialysis plant In diacid room 37.

Wherein, the 3rd salt chamber inlet 210 can export with the absorbing liquid of desulfurizing tower 1 and be connected.Through the 3rd salt chamber inlet 210 Import the absorbing liquid that desulfurizing tower 1 is discharged.When device is driven, can be through the second alkali chamber inlet 212 and the second acid chamber inlet 211 Import water.Under the effect of the second negative electrode 201 and the electric field of second plate 206 formation, OH in the second alkali room 35^-Ion Enrichment, H in the second acid room 37⁺Ion enrichment, the Na in the 3rd salt room 36⁺Ion enters the second alkali room 35 and OH^- Ion formed containing NaOH aqueous solution can continue to absorb SO₂The first dialysate, formation can continue to absorb SO₂ The first dialysate through second alkali room export 207 derivation.Second alkali room outlet 207 can enter with the absorbent of desulfurizing tower 1 Mouth connects.What the second alkali room outlet 207 was derived can continue to absorb SO₂The first dialysate can be used for as absorbent Desulfurization in desulfurizing tower 1 processes.HSO in 3rd salt room 36₃ ^-、SO₃ ^2-And SO₄ ^2-Enter the second acid room 37 and and H⁺Ion is formed containing H₂SO₃And H₂SO₄Be enriched H₂SO₃The second dialysate, by second acid room outlet 208 Discharge.There is on 3rd salt room 36 the 3rd salt room outlet 209, can be used for the material discharged in the 3rd salt room 36 and circulate into Enter in the 3rd salt room 36.

Wherein, described three compartment bipolar membrane electrodialysis devices 303 can have and are arranged at the second negative electrode 201 and second plate 206 Between many groups of three compartment bipolar membrane electrodialysis films pair；And two group of three adjacent compartment bipolar membrane electrodialysis film centering, previous Organize the 4th Bipolar Membrane of three compartment bipolar membrane electrodialysis films pair as the 3rd pair of later group three compartment bipolar membrane electrodialysis film pair Pole film.Such as, 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 3rd Bipolar Membrane the 202, second cation exchange membrane the 203, second anion exchange membrane 204 and the 4th Bipolar Membrane 205, the Form the second alkali room 35 between three Bipolar Membrane and the second cation exchange membrane 203, the second cation exchange membrane 203 with cloudy from Form the 3rd salt room 36 between proton exchange 204, formed between the second anion exchange membrane 204 and the 4th Bipolar Membrane 205 Second acid room 37；Bipolar membrane electrodialysis film on the right side of Fig. 5 is to including the 4th Bipolar Membrane 205, cation exchange membrane 223, the moon Ion exchange membrane 224 and Bipolar Membrane 225, form the second alkali room between the 4th Bipolar Membrane 205 and cation exchange membrane 223 35, form the 3rd salt room 36 between cation exchange membrane 223 and anion exchange membrane 224, anion exchange membrane 224 with The second acid room 37 is formed between Bipolar Membrane 225.

Wherein, described second alkali room 35 can be provided with at least one second alkali room outlet 207；Described second acid room At least one second acid room outlet 208 can be provided with on 37；Described second alkali room outlet 207 and the absorption of desulfurizing tower 1 Agent entrance connects, and described second acid room outlet 208 is connected with desorber 4 entrance.

Wherein, room, pole, second plate 206 and quadrupole film can be formed between the second negative electrode 201 and the 3rd pole film 230 Room, pole can also be formed between 231.Room, pole can be contained pole liquid.Such as pole liquid can contain Na₂SO₄Aqueous solution. Wherein, the 3rd pole film 230 and three compartment bipolar membrane electrodialysis films between (the such as the 3rd pole film 230 and the 3rd Bipolar Membrane Between 202) another the second acid room 37 can be formed.Wherein, quadrupole film 231 and three compartment bipolar membrane electrodialysis films Between to, (such as between quadrupole film 231 and Bipolar Membrane 225) can form another one the second alkali room 35.

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

Preferably, it is also associated with solid-liquid separation between the entrance of described absorbing liquid circulating pump 6 and described absorbing liquid recovery system Device 2, the absorbing liquid outlet of described desulfurizing tower 1 is connected with the entrance of absorbing liquid circulating pump 6, described absorbing liquid circulating pump 6 Outlet be connected with the circulating absorption solution entrance of described desulfurizing tower 1 and the entrance of described solid-liquid separator 2；Described solid-liquid divides It is connected with the entrance of the absorbing liquid entrance of described desulfurizing tower 1 and described absorbing liquid recovery system from the purified liquor outlet of device 2.Can To use described solid-liquid separator 2 to carry out the solid constituent in separate absorbent liquid.Wherein, described solid-liquid separator 2 can be Depositor and/or filter.

Preferably, the exhanst gas outlet of described desulfurizing tower 1 is additionally provided with filter 7 and/or liquid drop separator 8.Can make The dust in the flue gas that desulfurizing tower 1 is discharged is removed with described filter 7.Described liquid drop separator 8 can be used to remove Remove the drop carried secretly in the flue gas that desulfurizing tower 1 discharges.

Wherein, under preferable case, described absorbent contains NaOH and/or Na₂SO₃；By control flue gas flow and The flow of absorbent so that NaHSO in absorbing liquid₃With Na₂SO₃Mol ratio be (0.1-100): 1, more preferably (1-30):1.Wherein, in theory, the NaOH of 1 mole can absorb the SO of 1 mole₂Obtain the NaHSO of 1 mole₃； The NaOH of 2 moles can absorb the SO of 1 mole₂Obtain the Na of 1 mole₂SO₃；The Na of 1 mole₂SO₃Can absorb The SO of 1 mole₂Obtain the NaHSO of 2 moles₃.Such as, for the content of sulfur dioxide by volume in FCC flue gas For the flue gas of 700-900ppm, in the case of using the aqueous solution of NaOH of 8-12mol/L as absorbent, control The flow of flue gas is (40-100) ten thousand m³/ h, the flow of absorbent is 1-20m³/ h, NaHSO in the absorbing liquid obtained₃ With Na₂SO₃Mol ratio be (7-9): 1.

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

Wherein, under preferable case, (include voltage and/or electrodialysis by the service condition controlling bipolar membrane electrodialysis device Time), enabling continue to absorb SO₂The pH value of the first dialysate higher than 8, preferably more than 10.Wherein, may be used In the case of the voltage substantial constant in keeping bipolar membrane electrodialysis device, by the regulation electrodialysis time so that Can continue to absorb SO₂The pH value of the first dialysate be more than 8, preferably more than 10.Such as, for FCC flue gas In the flue gas that content is 700-900ppm of sulfur dioxide by volume, at the aqueous solution of the NaOH using 8-12mol/L In the case of absorbent, the flow controlling flue gas is (40-60) ten thousand m³/ h, the flow of absorbent is 3-10m³/ h, NaHSO in the absorbing liquid obtained₃With Na₂SO₃Mol ratio be (7-9): 1；Each group of bipolar membrane electrodialysis film is to upper applying Voltage when being 2-3V, the electrodialysis time is 5-60min, it is possible to continue to absorb SO₂The pH value of the first dialysate be 10.0-13.5。

Wherein, under preferable case, the condition of desorbing makes the H in stripping liquid₂SO₃Content be 0.01-0.4mol/L, solve SO in air-breathing₂Content is 7-99.9 volume %.Wherein, desorber can be vacuum column.Such as, it is enriched H₂SO₃ The second dialysate in H₂SO₃Content be 0.5-1.25mol/L, the tower top temperature of desorbing can be 0-100 DEG C, at the bottom of tower temperature Degree can be 0-100 DEG C, and feeding temperature can be 20-35 DEG C, and the tower top pressure of vacuum stripper is 0.01-1Pa, this solution H in the stripping liquid obtained under the conditions of suction₂SO₃Content be 0.01-0.04mol/L, the SO in stripping gas₂Content is 7-97 Volume %.

In the present invention, described absorbent is aqueous solution, and containing NaOH, Na₂SO₃, in ammonia and water-soluble organic amine At least one.Preferably, described absorbent is aqueous solution, and containing NaOH and/or Na₂SO₃.As the present invention's Another embodiment, described absorbent is aqueous solution, and containing ammonia；Wherein, the concentration of ammonia can be 1-10 weight Amount %.As another embodiment of the invention, described absorbent is aqueous solution, and containing water-soluble organic amine；Its In, the concentration of water-soluble organic amine can be 1-50 weight %.Wherein, water-soluble organic amine can include but not limited to three At least one in methylamine, triethylamine, ethylenediamine and dimethylformamide.

Wherein it is preferred to, sulfur-containing smoke gas is carried out in desulfurizing tower 1 with contacting of absorbent.In order to improve desulfurization further The SO of tower 1₂Absorption efficiency, wherein, it is highly preferred that the bottom of described desulfurizing tower 1 has smoke inlet, described The top of desulfurizing tower 1 has exhanst gas outlet, is disposed with at least one spraying layer from top to bottom in described desulfurizing tower 1 With at least one sieve tray, and described spraying layer and described sieve tray be arranged on described smoke inlet and described exhanst gas outlet it Between, wherein, described spraying layer is provided with the spray element with absorbent pipeline connection, described spray element include by The atomizer that inorganic porous sintered material is formed；Described absorbent spray in described atomizer and with described desulfurizing tower 1 In flow from bottom to up described sulfur-containing smoke gas contact.

Wherein, sulfur-containing smoke gas can be imported in described desulfurizing tower 1 by described smoke inlet, and described exhanst gas outlet can be by de- Flue gas after sulphuring treatment is derived from described desulfurizing tower 1, and described flue gas can flow in described desulfurizing tower 1 from bottom to up Dynamic, described spraying layer 2 can spray the absorbent of the oxysulfide absorbed in flue gas, and described sieve tray 3 can slow down institute State the flow velocity of absorbent and described flue gas so that described absorbent can be fully contacted described flue gas.It is being applied to described suction Receiving under the driving of the pressure in agent, partly or entirely can pass through in described absorbent is formed by inorganic porous sintered material Atomizer on micropore ejection and be atomized.

Wherein, described inorganic porous sintered material can be the various inorganic porous sintering for filtration that can be commercially available Material；Preferably, the average pore size of described inorganic porous sintered material is 1nm-50 μm, and porosity is 10-70%.

Wherein, it is further preferred that the average pore size of described inorganic porous sintered material is 50nm-2 μm.Excellent at this In the case of choosing, the fume desulfurizing tower of the present invention can obtain better atomizing effect at lower pressures.

Wherein, the material of described inorganic porous sintered material not particularly requirement, the most described inorganic porous sintered material Including at least one in porous metals sintered material, porous ceramic film material and porous silicon carbide.Porous ceramic film material is permissible Including at least one in silicon oxide ceramics film, alumina ceramic membrane, zirconia ceramics film and titanium oxide ceramics film, in order to Reduce the absorbent corrosion to ceramic membrane, it is preferable that described porous ceramic film material includes that alumina ceramic membrane, zirconium oxide are made pottery At least one in porcelain film and titanium oxide ceramics film.

Wherein, described inorganic porous sintered material can be monolayer, it is also possible to be multilamellar, the most described inorganic porous sintering Material can include porous matrix and key-course, and the average pore size of described key-course is more than the average pore size of described porous matrix.

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

Wherein, the material of described porous matrix can be conventional selection, it is preferable that described tubular porous matrix is pottery Porous matrix and/or rustless steel porous matrix.The material of described key-course can also be conventional selection, the most described control Layer can be ceramic membrane.

Wherein, described porous matrix can be uniform one layer, it is preferable that described porous matrix includes supporting layer and setting Transition zone between described supporting layer and described key-course, the bore dia of described supporting layer is more than the Kong Zhi of described transition zone Footpath.Described transition zone can reduce the hole plug degree of described key-course, extends the use of described electrodeless porous sintered material Life-span.Wherein, as a kind of embodiment, the outer wall of described supporting layer is attached with transition zone, outside described transition zone Being attached with key-course on wall, described absorbent first passes through described supporting layer, then through described transition zone, is then passed through described Key-course ejection atomization.Wherein, alternatively embodiment, the inwall of described supporting layer is attached with transition zone, Being attached with key-course on the inwall of described transition zone, described absorbent first passes through described key-course, then through described transition zone, It is then passed through the ejection atomization of described supporting layer.

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

Wherein, the not particularly requirement of the quantity of described spraying layer and described sieve tray, can be the most one or more, Preferably, described spraying layer is at least two, and described sieve tray is at least two, and described spraying layer and described sieve tray It is alternately disposed in described desulfurizing tower 1.

Wherein it is preferred to, it is provided with cleaner unit between described exhanst gas outlet and described spraying layer the most from top to down and except mist Device；Absorption liquid pool it is additionally provided with, by having between described absorption liquid pool and described spraying layer at the bottom of tower below described smoke inlet The pipeline having absorbing liquid circulating pump connects.

Wherein, described cleaner unit can remove the solid dust in described flue gas, and described demister can remove in flue gas and press from both sides The mist of band.Described cleaner unit can be bag-type dust collector and/or membrane tube defecator.Described demister can be silk screen Demister.Described absorption liquid pool can collect the suction obtained after contacting with sulfur-containing smoke gas with absorbent in described desulfurizing tower 1 Receive liquid.Absorbing liquid circulation can be pumped in the pipeline of described spraying layer by described absorbing liquid circulating pump again, and state described in warp Spray element ejection atomization in spraying layer.

Wherein, described spray element can all atomizers formed by inorganic porous sintered material, it is also possible to part For the atomizer formed by inorganic porous sintered material, remainder is conventional nozzle.

Wherein, in order to alleviate the stopping state of the atomizer formed by inorganic porous sintered material, it is preferable that described spray Drench and between element and described absorbent pipeline, be provided with the first dust filter unit preventing dust from entering described spray element.

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

Wherein, by the SO in described stripping gas₂It is oxidized to SO₃And obtain with oxidation with water in described first stripping liquid SO₃Reaction is to generate H₂SO₄Process can be with one turn of one suction, double-absorption, three-conversion three-absorption or the side of non-stationary transformantion Formula is carried out.Wherein, described one turn of one suction, described double-absorption, described three-conversion three-absorption and described non-stationary transformantion are sulphuric acid Conventional use of process in preparation field.Such as, document (Wang Shijuan etc., summarize, southern by sulfuric acid conversion process progress Logical Vocational University journal, calendar year 2001 December) have been disclosed for described one turn of one suction, described double-absorption and described three turn three The process inhaled.Also there are document (Ji Luo army etc., the application of low-concentration flue gas non-stationary transformantion acid-making process, sulphuric acid work Industry, 2006 (6), 5-10) have been disclosed for the process of described non-stationary transformantion.Specifically, described one turn one inhale Process includes SO₂Import SO₂Converter once converts, to be converted into containing SO₂And SO₃'s Converted product once absorbs, and after then once absorbing, remaining gas is as the tail gas of Sulphuric acid；Described two turn two The process inhaled includes SO₂Import SO₂Converter is carried out convert for the first time, to be converted into containing SO₂With SO₃The first converted product carry out absorbing for the first time, after then absorbing for the first time, remaining gas imports SO again₂Convert Tower carries out second time convert, with the SO in remaining gas after absorbing for the first time₂It is converted into SO₃, to being converted into Containing SO₂And SO₃The second converted product carry out second time absorb, then will second time absorb after remaining gas make Tail gas for Sulphuric acid.The process of described three-conversion three-absorption includes SO₂Import SO₂Converter is carried out turn for the first time Change, to be converted into containing SO₂And SO₃The first converted product carry out absorbing for the first time, then will absorb for the first time Rear remaining gas imports SO again₂Converter carries out second time convert, with in remaining gas after absorbing for the first time SO₂It is converted into SO₃, to be converted into containing SO₂And SO₃The second converted product carry out second time absorb, then will After second time absorbs, remaining gas imports SO again₂Converter carries out third time convert, to remain after third time being absorbed Gas in SO₂It is converted into SO₃, to be converted into containing SO₂And SO₃The 3rd converted product carry out third time Absorbing, after then third time being absorbed, remaining gas is as the tail gas of Sulphuric acid.Wherein, by SO₂It is converted into SO₃'s Device and condition can be conventional selection, and the present invention does not repeats them here.Wherein, by be converted into containing SO₂With SO₃Converted product carry out the device that absorbs and condition can be conventional selection, the present invention does not repeats them here.Wherein, The tail gas of above-mentioned Sulphuric acid can return step (a) as a part for sulfur-containing smoke gas to be carried out and the contacting of absorbent.

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

Wherein it is preferred to, the method for the present invention also includes: absorbs with the concentrated sulphuric acid that concentration is 97-99 weight % and aoxidizes The SO arrived₃, obtain the first sulphuric acid；With the concentrated sulphuric acid that concentration is 97-99 weight %, described stripping gas is dried, to inhale Receive the water in described stripping gas, obtain the second sulphuric acid；By described first sulphuric acid, described second sulphuric acid and described first desorbing Liquid mixes, and the condition of mixing makes the concentration of sulphuric acid in the material being mixed to get be 97-99 weight %.

Wherein, described first sulphuric acid can be oleum, can think SO₃The sulfur that mass fraction is 1-66 weight % Acid, the concentration of described second sulphuric acid can be less than 97 weight %, it is preferable that the amount of the water in described first stripping liquid and institute It is 97-99 weight % that the summation of the amount stating the water in stripping gas enables to the concentration of described 3rd sulphuric acid.

Wherein it is preferred to, the method for the present invention also includes: adds water in described electrodialysis plant, adds the amount of water not Summation less than the amount of the water in the amount of the water in described first stripping liquid and described stripping gas.

Wherein it is preferred to, the SO obtained with the water in described first stripping liquid and the water sorption enhanced in described stripping gas₃ Reaction is to generate H₂SO₄During produce waste gas as sulfur-containing smoke gas a part return step (a) carry out with absorb The contact of agent.In this preferred implementation, preparing the waste gas in sulphuric acid stage can return for desulfurization, thus further Reduce the discharge capacity of oxysulfide.

Wherein it is preferred to, the stripping gas that the gas outlet through desorber 4 discharges is imported in exsiccator 5, goes to be dried Except the moisture carried secretly in stripping gas, desiccant used in exsiccator 5 can be the concentrated sulphuric acid of 97-99 weight %, 97-99 The concentrated sulphuric acid of weight % can be in pipeline 583 imports described exsiccator 5, the water carried secretly in absorbing described stripping gas After Fen, obtain the second sulphuric acid, derive through pipeline 585.

Wherein it is possible to dry stripping gas is successively heated to by the second heat exchanger 52 and First Heat Exchanger 51 400-440 DEG C, to reach SO₂It is converted into SO₃Reaction temperature, be then introduced into SO₂Converter 53 is oxidized to Containing SO₃Once conversion gas, by described once convert gas be directed into the first sulfuric acid absorption tower 56 through the second heat exchanger 52 Middle concentrated sulphuric acid (concentration 97-99 weight %, preferably 98 weight %) absorbs, and generates the first sulphuric acid and first and absorbs residue Gas.Wherein, the second heat exchanger 52 and First Heat Exchanger 51 are respectively used to SO₂It is converted into SO₃Time produce heat Stripping gas after heat drying.

Successively it is heated to through the 4th heat exchanger 55 and the 3rd heat exchanger 54 wherein it is possible to absorb residual gas by first 400-440 DEG C, to reach SO₂It is converted into SO₃Reaction temperature, be then introduced into SO₂Converter 53 is oxidized to Containing SO₃Twice transformation gas, described twice transformation gas is directed into the second sulfuric acid absorption tower 57 through the 4th heat exchanger 55 Middle concentrated sulphuric acid (concentration 97-99 weight %, preferably 98 weight %) absorbs, and generates the 3rd sulphuric acid and second and absorbs residue Gas.

Wherein it is possible to by above-mentioned first sulphuric acid in pipeline 586 imports sulfuric acid dilution device 58, by above-mentioned 3rd sulphuric acid warp Pipeline 587 imports in sulfuric acid dilution device 58, by described second sulphuric acid in pipeline 585 imports sulfuric acid dilution device 58, and will Described first stripping liquid is in pipeline 42 imports sulfuric acid dilution device 58.The amount of the first stripping liquid that can be imported by control, Controlling the sulfuric acid concentration in sulfuric acid dilution device 58 is 97-99 weight %, preferably 98 weight %.Sulfuric acid dilution device 58 In the sulphuric acid of 97-99 weight % can export as finished product sulfuric acid through piping 581, it is also possible to derive through pipeline 582 and be used for It is dried and SO₃Absorption.Wherein, the sulphuric acid of 97-99 weight % for being dried can be directed into dry through piping 583 In device 5, it is used for absorbing SO₃The sulphuric acid of 97-99 weight % can be directed respectively into the first sulfuric acid absorption through piping 584 In tower 56 and the second sulfuric acid absorption tower 57.

Wherein it is possible to described stripping liquid is split into the first stripping liquid derived through pipeline 42 and through pipe by flow divider 41 During the second stripping liquid that road 43 is derived, the ratio between the first stripping liquid and the second stripping liquid can be because of sulfuric acid dilution device 58 In water requirement depending on.

In the present invention, two compartment bipolar membrane electrodialysis films to and the Bipolar Membrane of three compartment bipolar membrane electrodialysis film centerings, sun from Proton exchange and anion exchange membrane all can obtain by buying the film product of commercialization.Such as can be from Zhejiang thousand Autumn environment-protective water processes company limited and is commercially available.

Further describe the present invention by the following examples.In following example, use the mixed of nitrogen and sulfur dioxide Closing gas to test as the flue gas simulated, in this gaseous mixture, by volume, the content of FCC sulfur dioxide in flue gas is 800ppm。

Embodiment 1

With reference to Fig. 1 and Fig. 2, flue gas enters desulfurizing tower 1 through the smoke inlet 11 of desulfurizing tower 1, desulfurizing tower 1 in and Absorbent contacts, and to obtain desulfurization process, then discharges desulfurizing tower 1 through exhanst gas outlet 12.At fume treatment Initial period, absorbent is the sodium hydroxide of 1mol/L.Wherein, the flow controlling flue gas is 500,000 m³/ h, absorbent Flow be 4m³/ h, NaHSO in the absorbing liquid obtained₃With Na₂SO₃Mol ratio be 8:1.

Use two compartment bipolar membrane electrodialysis devices 301 as bipolar membrane electrodialysis device, import through the first salt chamber inlet 107 The absorbing liquid that desulfurizing tower 1 is discharged.At the initial period of fume treatment, import water through the first alkali chamber inlet 108.First Under the effect of the electric field that negative electrode 101 and the first anode 105 are formed, OH in the first alkali room 31^-Ion enrichment, the first salt room H in 32⁺Ion enrichment, the Na in the first salt room 32⁺Ion enters the first alkali room through the first cation exchange membrane 103 31 and and OH^-Ion formed NaOH aqueous solution, formation containing NaOH aqueous solution can continue to absorb SO₂? One dialysate exports 109 derivation through the first alkali room.First alkali room outlet 109 is connected with the absorbent entrance of desulfurizing tower 1. What the first alkali room outlet 109 was derived can continue to absorb SO₂The first dialysate as absorbent in the desulfurizing tower 1 Desulfurization processes.HSO in first salt room 32₃ ^-And SO₃ ^2-With H⁺Ion forms H₂SO₃, obtain containing H₂SO₃Richness Collect H₂SO₃The second dialysate, be enriched H₂SO₃The second dialysate by first salt room outlet 106 discharge.Two When each group of two compartment bipolar membrane electrodialysis films in compartment bipolar membrane electrodialysis device 301 are 2.5V to the voltage of upper applying, The electrodialysis time is 30min, it is possible to continue to absorb SO₂The pH value of the first dialysate be 12, in the first salt room 32 Na⁺Concentration maintain below 300ppm.

First salt room outlet 106 is connected with the entrance of desorber 4.By being enriched of the first salt room outlet 106 discharge H₂SO₃The second dialysate obtain desorbing at desorber 4, discharge stripping gas.There is on desorber 4 gas outlet and liquid Body exports.After desorbing, the stripping gas of release is discharged through gas outlet.The stripping gas of discharge is oxidized is converted into SO₃.Release SO₂Rear remaining material is discharged as stripping liquid liquid outlet on desorber 4.The tower top temperature of desorbing is 4 DEG C, Column bottom temperature is 95 DEG C, and feeding temperature is 30 DEG C, and the tower top pressure of vacuum stripper is 0.5Pa, in the stripping liquid obtained H₂SO₃Content be 0.03mol/L, the SO in stripping gas₂Content is 95 volume %.

Described stripping liquid is split into the first stripping liquid and the second stripping liquid, obtains with described first stripping liquid sorption enhanced SO₃To generate H₂SO₄；Described second stripping liquid reuse to described electrodialysis plant will be enriched with H₂SO₃；And to described Electrodialysis plant supplements SO₃It is converted into the water that concentrated sulphuric acid is consumed.Described second stripping liquid reuse is directed into described In the described first salt room 32 of electrodialysis plant.Wherein, the water supplemented in described electrodialysis plant imports described first salt In room 32.

Wherein, the stripping gas that the gas outlet through desorber 4 discharges is imported in exsiccator 5, with dry removal stripping gas In the moisture carried secretly, the concentrated sulphuric acid that desiccant is 98 weight % used in exsiccator 5, the concentrated sulphuric acid of 98 weight % is through pipe Road 583 imports in described exsiccator 5, after the moisture carried secretly, obtains the second sulphuric acid, warp in absorbing described stripping gas Pipeline 585 is derived.

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 SO₂Converter 53 is oxidized to containing SO₃Once conversion gas, Gas is once converted in the second heat exchanger 52 is directed into the first sulfuric acid absorption tower 56 with concentrated sulphuric acid (concentration 98 weight by described Amount %) absorb, generate the first sulphuric acid and first and absorb residual gas.Wherein, the second heat exchanger 52 and First Heat Exchanger 51 It is respectively used to SO₂It is converted into SO₃Time the heat that the produces stripping gas after the heat drying.

Absorb residual gas by first and be successively heated to 420 DEG C through 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 SO₂Converter 53 is oxidized to containing SO₃Secondary turn Activating QI, uses concentrated sulphuric acid (concentration in the 4th heat exchanger 55 is directed into the second sulfuric acid absorption tower 57 by described twice transformation gas 98 weight %) absorb, generate the 3rd sulphuric acid and second and absorb residual gas.

Wherein, by above-mentioned first sulphuric acid in pipeline 586 imports sulfuric acid dilution device 58, by above-mentioned 3rd sulphuric acid through pipeline 587 import in sulfuric acid dilution devices 58, by described second sulphuric acid in pipeline 585 imports sulfuric acid dilution device 58, by described the One stripping liquid is in pipeline 42 imports sulfuric acid dilution device 58.By the amount of the first stripping liquid that control imports, control sulfur Sulfuric acid concentration in acid diluter 58 is 98 weight %.A part in the sulphuric acid of 98 weight % in sulfuric acid dilution device 58 Exporting as finished product sulfuric acid through piping 581, another part is derived for being dried and SO through pipeline 582₃Absorption.Wherein, For the sulphuric acid of 98 dry weight % in piping 583 is directed into exsiccator 5, it is used for absorbing SO₃98 weight % Sulphuric acid be directed respectively into the first sulfuric acid absorption tower 56 and the second sulfuric acid absorption tower 57 through piping 584.

Wherein, described stripping liquid is split into the first stripping liquid derived through pipeline 42 and through pipeline 43 by flow divider 41 During the second stripping liquid derived, the ratio between the first stripping liquid and the second stripping liquid is because of the water requirement in sulfuric acid dilution device 58 Depending on.

Wherein, the second stripping liquid reuse is directed in the described first salt room 32 of described electrodialysis plant；Further, to Supplementing water in first salt room 32, the amount supplementing water is by SO₃It is converted into the amount that concentrated sulphuric acid is consumed, the most described first desorbing Water content in liquid.

Embodiment 2

With reference to Fig. 3 and Fig. 4, flue gas enters desulfurizing tower 1 through the smoke inlet 11 of desulfurizing tower 1, desulfurizing tower 1 in and Absorbent contacts, and to obtain desulfurization process, then discharges desulfurizing tower 1 through exhanst gas outlet 12.At fume treatment Initial period, absorbent is the sodium hydroxide of 1mol/L.Wherein, the flow controlling flue gas is 500,000 m³/ h, absorbent Flow be 4m³/ h, NaHSO in the absorbing liquid obtained₃With Na₂SO₃Mol ratio be 8:1.

Use two compartment bipolar membrane electrodialysis devices 302 as bipolar membrane electrodialysis device, import through the second salt chamber inlet 138 The absorbing liquid that desulfurizing tower 1 is discharged.When electrodialysis starts, import water through the first acid chamber inlet 137.At the first negative electrode 101 Under effect with the electric field of the first anode 105 formation, OH in the second salt room 33^-Ion enrichment, H in the first acid room 34⁺、 HSO₃ ^-And SO₃ ^2-Ion enrichment, is formed and is enriched H₂SO₃The second dialysate, the NaHSO in the second salt room 33₃With OH^-Ion forms Na₂SO₃Aqueous solution, is formed containing Na₂SO₃Aqueous solution can continue to absorption SO with NaOH solution₂ The first dialysate through second salt room export 139 derivation.Second salt room outlet 139 connects with the absorbent entrance of desulfurizing tower 1 Connect.The desulfurization that second saline solution of the second salt room outlet 139 derivation is back in desulfurizing tower 1 processes.First acid room 34 is formed Be enriched H₂SO₃The second dialysate, by first acid room outlet 136 discharge.Two compartment bipolar membrane electrodialysis devices 3 In each group of two compartment bipolar membrane electrodialysis film when being 2.5V to the voltage of upper applying, the electrodialysis time is 30min, it is possible to Continue to absorb SO₂The pH value of the first dialysate be 12.5.

First acid room outlet 136 is connected with the entrance of desorber 4.By being enriched of the first acid room outlet 136 discharge H₂SO₃The second dialysate obtain desorbing at desorber 4, discharge stripping gas.There is on desorber 4 gas outlet and liquid Body exports.After desorbing, the stripping gas of release is discharged through gas outlet.The stripping gas of discharge is oxidized is converted into SO₃.Release SO₂Rear remaining material is stripping liquid, and the liquid outlet on desorber 4 is discharged.The tower top temperature of desorbing is 3 DEG C, Column bottom temperature is 97 DEG C, and feeding temperature is 30 DEG C, and the tower top pressure of vacuum stripper is 0.8Pa, in the stripping liquid obtained H₂SO₃Content be 0.03mol/L, the SO in stripping gas₂Content is 95 volume %.

Described stripping liquid is split into the first stripping liquid and the second stripping liquid, obtains with described first stripping liquid sorption enhanced SO₃To generate H₂SO₄；Described second stripping liquid reuse to described electrodialysis plant will be enriched with H₂SO₃；And to described Electrodialysis plant supplements SO₃It is converted into the water that concentrated sulphuric acid is consumed.Described second stripping liquid reuse is directed into described In the described first acid room 34 of electrodialysis plant.Wherein, the water supplemented in described electrodialysis plant imports described first acid In room 34.

Wherein, the second stripping liquid reuse is directed in the described first acid room 34 of described electrodialysis plant；Further, to Supplementing water in first acid room 34, the amount supplementing water is by SO₃It is converted into the amount that concentrated sulphuric acid is consumed, the most described first desorbing Water content in liquid.

Embodiment 3

With reference to Fig. 5 and Fig. 6, flue gas enters desulfurizing tower 1 through the smoke inlet 11 of desulfurizing tower 1, desulfurizing tower 1 in and Absorbent contacts, and to obtain desulfurization process, then discharges desulfurizing tower 1 through exhanst gas outlet 12.At fume treatment Initial period, absorbent is the sodium hydroxide of 1mol/L.Wherein, the flow controlling flue gas is 500,000 m³/ h, absorbent Flow be 4m³/ h, NaHSO in the absorbing liquid obtained₃With Na₂SO₃Mol ratio be 8:1.

Use three compartment bipolar membrane electrodialysis devices 303 as bipolar membrane electrodialysis device, the 3rd salt chamber inlet 210 and desulfurization The absorbing liquid outlet of tower 1 connects.The absorbing liquid that desulfurizing tower 1 is discharged is imported through the 3rd salt chamber inlet 210.When device is driven, Water is imported through the second alkali chamber inlet 212 and the second acid chamber inlet 211.Formed at the second negative electrode 201 and second plate 206 Electric field effect under, OH in the second alkali room 35^-Ion enrichment, H in the second acid room 37⁺Ion enrichment, the 3rd salt room Na in 36⁺Ion enters the second alkali room 35 and OH^-Ion formed containing NaOH aqueous solution can continue to absorb SO₂The first dialysate, formation can continue to absorb SO₂The first dialysate through second alkali room export 207 derivation. Second alkali room outlet 207 is connected with the absorbent entrance of desulfurizing tower 1.What the second alkali room outlet 207 was derived can continue to inhale Receive SO₂The first dialysate process as absorbent desulfurization in the desulfurizing tower 1.HSO in 3rd salt room 36₃ ^-、 SO₃ ^2-And SO₄ ^2-Enter the second acid room 37 and and H⁺Ion is formed containing H₂SO₃And H₂SO₄Be enriched H₂SO₃? Two dialysates, by the second acid room outlet 208 discharge.There is on 3rd salt room 36 second salt room outlet 209, can be used for Discharge the material in the 3rd salt room 36 and be recycled in the 3rd salt room 36.

Second acid room outlet 208 is connected with the entrance of desorber 4.By being enriched of the second acid room outlet 208 discharge H₂SO₃The second dialysate obtain desorbing at desorber 4, discharge stripping gas.There is on desorber 4 gas outlet and liquid Body exports.After desorbing, the stripping gas of release is discharged through gas outlet.The stripping gas of discharge is oxidized is converted into SO₃.Release SO₂Rear remaining material is stripping liquid, and the liquid outlet on desorber 4 is discharged.The tower top temperature of desorbing is 3 DEG C, Column bottom temperature is 97 DEG C, and feeding temperature is 30 DEG C, and the tower top pressure of vacuum stripper is 0.8Pa, in the stripping liquid obtained H₂SO₃Content be 0.03mol/L, the SO in stripping gas₂Content is 95 volume %.

Described stripping liquid is split into the first stripping liquid and the second stripping liquid, obtains with described first stripping liquid sorption enhanced SO₃To generate H₂SO₄；Described second stripping liquid reuse to described electrodialysis plant will be enriched with H₂SO₃；And to described Electrodialysis plant supplements SO₃It is converted into the water that concentrated sulphuric acid is consumed.Described second stripping liquid reuse is directed into described In the described second acid room 37 of electrodialysis plant.Wherein, the water supplemented in described electrodialysis plant imports described second acid In room 37.

Wherein, the second stripping liquid reuse is directed in the described second acid room 37 of described electrodialysis plant；Further, to Supplementing water in second acid room 37, the amount supplementing water is by SO₃It is converted into the amount that concentrated sulphuric acid is consumed, the most described first desorbing Water content in liquid.

Embodiment 1-3 illustrates the preferred embodiment of the present invention, it is seen that the present invention can be by flue gas SO₂It is converted into concentrated sulphuric acid fully, and can substantially realize no effuent discharge, effectively reclaim absorbing liquid.

The preferred embodiment of the present invention is described in detail above in association with accompanying drawing, but, the present invention is not limited to above-mentioned enforcement Detail in mode, in the technology concept of the present invention, can carry out multiple letter to technical scheme Monotropic type, these simple variant belong to protection scope of the present invention.

It is further to note that each the concrete technical characteristic described in above-mentioned detailed description of the invention, in not contradiction In the case of, can be combined by any suitable means, in order to avoid unnecessary repetition, the present invention is to various Possible compound mode illustrates the most separately.

Additionally, combination in any can also be carried out between the various different embodiment of the present invention, as long as it is without prejudice to this Bright thought, it should be considered as content disclosed in this invention equally.

Claims

1. one kind utilize sulfur-containing smoke gas produce concentrated sulphuric acid method, it is characterised in that: the method include as Lower step:

A sulfur-containing smoke gas is contacted by () with absorbent, obtain the flue gas after desulfurization and absorbing liquid；Described suction Receipts agent is alkaline aqueous solution；

B described absorbing liquid importing bipolar membrane electrodialysis device is carried out electrodialysis by (), be can continue to Absorb SO₂The first dialysate and be enriched H₂SO₃The second dialysate；Described first dialysate is returned It is used as partly or entirely contacting of absorbent with flue gas；

C described second dialysate is carried out desorbing by (), obtain stripping liquid and containing SO₂Stripping gas；

D () is by the SO in described stripping gas₂It is oxidized to SO₃, described stripping liquid is split into the first solution Imbibition and the second stripping liquid, make the SO that the water in described first stripping liquid obtains with oxidation₃Reaction generates H₂SO₄；Described second stripping liquid reuse to described electrodialysis plant will be enriched with H₂SO₃。

Method the most according to claim 1, wherein, described bipolar membrane electrodialysis device includes two Compartment bipolar membrane electrodialysis device (301)；Described two compartments bipolar membrane electrodialysis device (301) have setting Least one set two compartment bipolar membrane electrodialysis between the first negative electrode (101) and the first anode (105) Film pair, described two compartment bipolar membrane electrodialysis films are to including the first Bipolar Membrane (102), the first cation Exchange membrane (103) and the second Bipolar Membrane (104), the first Bipolar Membrane (102) is handed over the first cation Changing and form the first alkali room (31) between film (103), the second Bipolar Membrane (104) is handed over the first cation Change and between film (103), form the first salt room (32)；

Wherein, carry out described electrodialytic step to include: described absorbing liquid is passed through two compartment Bipolar Membrane electricity The first salt room (32) in dialyser (301) carries out electrodialysis, obtains in the first alkali room (31) Can continue to absorb SO₂The first dialysate, obtain being enriched H in described first salt room (32)₂SO₃ The second dialysate；Described second stripping liquid reuse is directed into described first salt of described electrodialysis plant In room (32).

Method the most according to claim 1, wherein, described bipolar membrane electrodialysis device includes two Compartment bipolar membrane electrodialysis device (302)；Described two compartments bipolar membrane electrodialysis device (302) have setting Least one set two compartment bipolar membrane electrodialysis between the first negative electrode (101) and the first anode (105) Film pair, described two compartment bipolar membrane electrodialysis films are to including the first Bipolar Membrane (102), the first anion Exchange membrane (140) and the second Bipolar Membrane (104), the first Bipolar Membrane (102) is handed over the first anion Changing and form the second salt room (33) between film (140), the second Bipolar Membrane (104) is handed over the first anion Change and between film (140), form the first acid room (34)；

Wherein, carry out described electrodialytic step to include: described absorbing liquid is passed through two compartment Bipolar Membrane electricity The second salt room (33) in dialyser (302) carries out electrodialysis, in described second salt room (33) Obtain can continue to absorb SO₂The first dialysate, be enriched in described first acid room (34) H₂SO₃The second dialysate；Described second stripping liquid reuse is directed into described in described electrodialysis plant In first acid room (34).

Method the most according to claim 1, wherein, described bipolar membrane electrodialysis device includes three Compartment bipolar membrane electrodialysis device (303)；Described three compartments bipolar membrane electrodialysis device (303) have setting Least one set three compartment bipolar membrane electrodialysis between the second negative electrode (201) and second plate (206) Film pair, described three compartment bipolar membrane electrodialysis films are 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 pair Forming the second alkali room (35) between pole film and the second cation exchange membrane (203), the second cation is handed over Change formation the 3rd salt room (36), the second anion between film (203) and anion exchange membrane (204) The second acid room (37) is formed between exchange membrane (204) and the 4th Bipolar Membrane (205)；

Wherein, carry out described electrodialytic step to include: described absorbing liquid is passed through three compartment Bipolar Membrane electricity The 3rd salt room (36) in dialyser (303) carries out electrodialysis, obtains in the second acid room (37) It is enriched H₂SO₃The second dialysate, obtain can continue in the second alkali room (35) absorbing SO₂ The first dialysate；Described second stripping liquid reuse is directed into described second acid of described electrodialysis plant In room (37).

5. according to the method described in any one in claim 1-4, wherein, described absorbent contains NaOH and/or Na₂SO₃。

6. according to the method described in any one in claim 1-4, wherein, sulfur-containing smoke gas and absorption The contact of agent is carried out in desulfurizing tower (1), and the bottom of described desulfurizing tower (1) has smoke inlet, The top of described desulfurizing tower (1) has exhanst gas outlet, depends on from top to bottom in described desulfurizing tower (1) Secondary at least one spraying layer and at least one sieve tray of being provided with, and described spraying layer and described sieve tray set Put between described smoke inlet and described exhanst gas outlet, wherein, described spraying layer is provided with and inhales Receiving the spray element of agent pipeline connection, described spray element includes the mist formed by inorganic porous sintered material Change nozzle；

Described absorbent spray in described atomizer and with described desulfurizing tower (1) in from bottom to up The described sulfur-containing smoke gas contact of flowing.

7. according to the method described in any one in claim 1-4, wherein, by described stripping gas SO₂It is oxidized to SO₃And with the water in described first stripping liquid and the SO that obtains of oxidation₃React to generate H₂SO₄Process carry out in the way of one turn of one suction, double-absorption, three-conversion three-absorption or non-stationary transformantion.

8. according to the method described in any one in claim 1-4, wherein, the method also includes: The SO that oxidation obtains is absorbed with the concentrated sulphuric acid that concentration is 97-99 weight %₃, obtain the first sulphuric acid；With dense Described stripping gas is dried, to absorb in described stripping gas by degree for the concentrated sulphuric acid of 97-99 weight % Water, obtains the second sulphuric acid；By described first sulphuric acid, described second sulphuric acid and described first stripping liquid mixing, The condition of mixing makes the concentration of sulphuric acid in the material being mixed to get be 97-99 weight %.

9. according to the method described in any one in claim 1-4, wherein, the method also includes: In described electrodialysis plant, add water, add the amount amount no less than the water in described first stripping liquid of water Summation with the amount of the water in described stripping gas.

10. according to the method described in any one in claim 1-4, wherein, by described stripping gas SO₂It is oxidized to SO₃And with the water in described first stripping liquid and the SO that obtains of oxidation₃React to generate H₂SO₄During produce waste gas as sulfur-containing smoke gas a part return step (a) carry out with described The contact of absorbent.