CN1320946C

CN1320946C - Acid solution spray dry-process flue gas desulfurization and modulating intensification method

Info

Publication number: CN1320946C
Application number: CNB2004100483751A
Authority: CN
Inventors: 陶国龙
Original assignee: Individual
Current assignee: Individual
Priority date: 2004-06-29
Filing date: 2004-06-29
Publication date: 2007-06-13
Anticipated expiration: 2024-06-29
Also published as: CN1593731A

Abstract

The present invention discloses an acid solution-spraying flue gas desulfurization and tempering intensification method of using a dry method, which is suitable for the fields of flue gas desulfurization/denitrification and flue gas tempering by using a dry method. An acid solution with the pH value not more than 5.5 is sprayed into flue gas containing pulverized coal ash/ particulates of a desulfurizing agent in a flue or a desulfurization reactor between the tail of a coal burning boiler and a dust remover in a fog-shaped form so that fog drops effectively catch the pulverized coal ash or the particulates of the desulfurization agent in the flue gas and form a liquid membrane on the surface of the flue gas, the residual liquid membrane has gradually low pH value and strong acidity along with the rapid evaporation of the moisture in the fog drops so as to be favorable for the dissolution of alkali metal ions and transition-state metal ions having catalysis and oxidization, and then the effective desulfurization constituents in the particulates are activated and participate in desulfurization reaction. Therefore, the present invention intensifies the tempering of the flue gas with the reduction of the specific resistance of dust and the oxidization extent to desulfurization by-products, reduces the proportion of unstable sulfite, decreases the consumption of CO2 in the flue gas to a Ca-group desulfurizing agent and enhances the utilization rate and the desulfurization efficiency of the desulfurizing agent of the dry method.

Description

Acid solution spraying dry flue gas desulphurization processing method

Technical field

The present invention relates to flue gas desulfurization or denitrogenation and dedusting field, particularly relate at the dry desulfurization of fire coal boiler fume or the flue gas conditioning processing technology field of denitrogenation and the soot emissions of reduction electric precipitation.

Background technology

Existing coal burning flue gas desulfurization technology can be divided into wet method, semidry method, dry method and special process substantially from the use of desulfurizing agent and the dried wet form of desulfurization product.Wherein, the main flow desulfur technology of high sulfur-bearing fire coal and 300MW and above large-scale coal-fired unit during wet method has become; And semidry method and dry method dry desulfurizing process particularly, because characteristics such as its equipment manufacturing cost is low, technology is simple, operating cost is low, water consumption is little, power consumption is low, take up an area of province, the repair and maintenance workload is little, the flue gas desulfurization of coal-fired and 200MW and following medium and small coal-fired unit of low sulfur-bearing in then comparatively being applicable to especially becomes one of mainstream technology to the fields such as desulfurization transformation that have old unit.

Relate to desulfurization by dry method just like 1. in-furnace calcium spraying afterbody humidification activation sulfur removal technology (week congruence; the activation flue-gas desulfurizing engineering is commented behind ShiShimonoseki power plant in-furnace calcium spraying stove; environmental protection for electric power; 2001; NO.2 P1～7); 2. in-furnace calcium spraying catalytic desulfurization technology (Chinese patent literature ZL01114878.8); 3. the charged dry-type jetting desulfur technology of absorbent (Chen Defang, charged dry sorbent injection desulphurization system, energy research and information; 1999; NO.1, P18～27), 4. coal self desulphurization during combustion and humidification activation technology (Zhou Yuegui etc.; dry type flue gas desulfurizing technical progress and application prospect analysis thereof; energy technology, 2001, NO.3 P18～27); 5. flue gas spray humidification simple desulfurization technology (Tao Guolong; the flue gas spray humidification improves electric cleaner Study on Efficiency and practice, electric precipitation and gas purification, 2003; NO.3, P1～11) etc.

Because coal-fired carbon, nitrogen, the sulfur oxide that produces in combustion process is acid anhydrides, water-soluble back forms acid solution, be based on the recognition, so present dry desulfurizing process generally adopts partial neutral or alkaline water as humidification activation liquid, with in and water absorb the acidity that produces behind the above-mentioned oxide, promote the SO in the flue gas ₂Absorption in the aqueous solution and hydrolysis, expectation is reacted the alkali metal ion as the desulfurization activating substance of its stripping in liquid phase and from desulfurizing agent or flyash, to improve the efficient of desulfurization, therefore the PH of used sometimes humidification activation liquid even up to more than 11, and think and be bound to will influence solution to the SO in the flue gas if adopts acid solution to make humidification activation liquid ₂Absorption so that influence desulfurization rate, thereby cause the desulfurized effect variation.But, following one or more deficiencies of these present dry desulfurizing process ubiquities:

(1) effective rate of utilization of desulfurizing agent is low, thereby causes the large usage quantity of desulfurizing agent.

As above-mentioned 1., 2. disclosed in-furnace calcium spraying sulfur removal technology, the apparent utilization rate of its desulfurization absorbent has only 26～30%, technology in-furnace calcium spraying afterbody humidification activation sulfur removal technology 1. particularly, behind about 15% the relative desulfuration efficiency of rejecting that flyash self produces under the afterbody humidification condition, the practical efficiency of its desulfurizing agent also has only 20～25%.

(2) activation effect of humidification activation link is poor, and desulfuration efficiency is low relatively, generally has only 30～50%.

(3) above-mentioned dry desulfurizing process causes the product of desulfuration in furnace with CaSO except that in-furnace calcium spraying catalytic desulfurization technology owing to added catalytic oxidant in the desulfurizing agent ₄Be that the desulfurization product oxygenation efficiency is low in all the other technologies, unsettled CaSO outside the master ₃Content is far longer than CaSO ₄Thereby, influence the utilization of desulfurization product.

(4) easily cause follow-up electric cleaner dust emission to exceed standard, more and more be subjected to certain restriction in the application of some occasion.

Dry desulfurizing process is because the absorbent utilization rate is low, use the absorbent consumption big, and contain the CaO that has neither part nor lot in reaction in a large number in the desulfurizing byproduct, the dust content that therefore occurs the electric cleaner inlet flue gas inevitably significantly increases, and flue dust increases etc. the situation that is unfavorable for dedusting than resistance.If do not take significantly humidification and be reduced to the cigarette temperature below 80 ℃ and a series of measures such as pre-dedusting, then follow-up electric cleaner dust emission will inevitably increase considerably and exceed standard, both made the above-mentioned measure of having taked, and, also be difficult to guarantee to satisfy≤100mg/Nm for the situation of high specific resistance flue dust ³Even stricter≤50mg/Nm ³Standard-required.

For the problems referred to above, people generally believe it is that the efficient of the desulfurizing agent selected for use is not high, thus attempt to adopt more efficiently desulfurizing agent or oxidation catalyst improving desulfurized effect, but the engineering effect is still not really desirable, and increased processing cost.

The inventor has carried out long term studies to existing dry desulfurizing process, think that it is not to be because the problem of desulfurizing agent itself fully that there is the reason of the problems referred to above in existing dry desulfurizing process, and be also that to a great extent people to humidification activation process understanding deficiency with because of technical prejudice, are emphasizing to adopt the particularly alkaline humidification activation liquid of partial neutral more to help absorbing SO ₂The time, ignored in dry desulfurizing process flyash or desulfurizing agent solid particulate matter neutral and alkali metal ion and have the dissolution rate of desulfurization effective ingredients such as transiting state metal ion of catalysed oxidn and stripping quantity to this key link of restriction of sweetening process.Because, in fact restrict the dry desulfurizing process desulfuration efficiency except SO ₂The absorption rate of dissolution outside, also have a crucial factor, be exactly whether to have the sufficient ion stripping that helps desulfurization to make to guarantee to consume the SO that humidification activation liquid is absorbed ₂If the dissolution rate and the stripping quantity of desulfurization effective ingredient do not catch up with in flyash or the desulfurizing agent solid particulate matter, can not in time consume the SO that drop absorbs ₂, then not only limited the humidification activation drop and further absorbed SO ₂Process, and the SO that in drop, absorbs ₂Can return flue gas again with the liquid evaporation, can reduce the desulfuration efficiency of humidification activation link equally greatly, can not effectively bring into play the effect of humidification activation.This is not a problem in wet method and semi-dry desulfurizing process because desulfurizing agent and flyash are to spray into the form that slurry drips in these two kinds of technologies, in the slurries just stripping enough ions that is used for desulfurization are arranged, and slurries are constantly to recycle.And the stroke from the humidification activation link to follow-up deduster is shorter in dry desulfurizing process, desulfurizing agent, droplet and flue gas to contact the coexistence time very short, generally have only several seconds, in the so short time, the dissolution rate of active ion and stripping quantity just seem particularly important in the solid particle, become the principal element that influences desulfurization rate.Existing dry desulfurizing process has only emphasized exactly that then activating solution is to SO ₂Absorption dissolving, and ignored this key issue of ion stripping.Main because:

(1) since in desulfurizing agent or the flyash the real composition that plays desulfidation and catalysed oxidn be that form with oxide exists, and the spray humidification activating solution that existing spraying desulfurization by dry method adopts generally is the partial neutral or the alkalescence of PH 〉=6, and under this environment, the contained alkaline metal ions Ca that helps desulfurization in desulfurizing agent and the flyash ²⁺, Mg ²⁺, Na ⁺, K ⁺Deng dissolution rate low, dissolution rate is slow; And to SO ₂Transiting state metal ion Fe with catalysed oxidn ³⁺, Fe ²⁺, Mn ²⁺, Ti ²⁺, Zn ²⁺Deng then more being difficult to stripping, and the pH value of humidification activation liquid is high more, and this dissolution characteristic is poor more, when PH 〉=5.5, almost is difficult to stripping, particularly for good catalytic activity and Fe cheap again, that be rich in ³⁺, Fe ²⁺, Mn ²⁺Even micro Fe is arranged ³⁺, Fe ²⁺, Mn ²⁺Stripping, also can be higher because of solution PH, can with solution in OH ^-Reaction generates insoluble precipitation of hydroxide.These reasons have caused the real effective rate of utilization of the favourable active ingredient of desulfurization lower, a large amount of effective ingredients has little time stripping or can't stripping and can not participate in desulfurization chemical reaction, therefore cause in the humidification activation link very poorly, be difficult to bring into play the desulfidation of activation link the activation effect of desulfurizing agent and flyash.

(2) CO in the flue gas ₂Recarbonation generate CaCO ₃Deposit and solution pH value have very confidential relation, and PH is high more, and the recarbonation phenomenon is outstanding more, in the humidification activation environment of higher pH value, and the Ca in the desulfurizing agent ²⁺With dissolve CO in the humidifying liquid ₂The CO that forms ₃ ^2-Very easily form insoluble CaCO ₃, cause Ca in the Ca base desulfurizer ²⁺Very big waste.Because CO in the coal-fired flue-gas ₂Content be generally about 13% and SO ₂Content generally also have only 0.04～0.4%, CO ₂Concentration is SO approximately ₂32～325 times of concentration, and the partial neutral of prior art or alkaline humidification activation liquid very easily absorb a large amount of CO from flue gas ₂Generate CO ₃ ^2-, and then with desulfurizing agent in the Ca of stripping ²⁺Reaction generates CaCO ₃, the CO under this condition in the flue gas ₂A large amount of and SO ₂Ca in the contention desulfurizing agent generates CaCO ₃Precipitation is separated out, and causes the very big waste of desulfurization effective ingredient.For example comparatively typical in-furnace calcium spraying afterbody humidification activation sulfur removal technology is through analyzing discovery to desulfurization product, its afterbody humidification activation link desulfurizing agent and SO ₂The Ca that reacts newly-generated desulfurization product consumption only accounts for 2～3% of total Ca, and and CO ₂React newly-generated CaCO ₃The Ca that consumes accounts for the about more than 30% of total Ca, effective desulfurization composition Ca in the visible desulfurizing agent ²⁺Waste very serious, this also is this type of technology humidification activation link sorbent utilization and desulfuration efficiency one of the main reasons on the low side.

(3) under partial neutral or alkaline humidification activation condition, SO ₃ ^2-Oxidation rate very low, and be difficult for stripping again, thereby cause in the product of dry desulfurization with CaSO owing to play the transiting state metal ion of catalysed oxidn ₃Be main.And CaSO ₃Unstable chemcial property, the one, decompose easily and cause secondary pollution, the 2nd, if CaSO ₃Content is too much, progressively is oxidized to CaSO under atmospheric environment or oxygen sufficiency ₄And be unfavorable for the volumetric expansion used, and then influence the use of desulfurization product or flyash.

Summary of the invention

At existing dry desulfurizing process above shortcomings, the object of the present invention is to provide a kind of acid solution spraying dry flue gas desulphurization processing method, by improving the alkaline metal ions and dissolution characteristic with transiting state metal ion of catalysed oxidn favourable, promote CaSO to desulfurization ₄Generation, to solve the problems referred to above that existing dry desulfurizing process exists pointedly.

Acid solution spraying dry flue gas desulphurization of the present invention and modified intensifying method comprise following process:

(1) flue gas that contains flyash or sorbent particle thing sprayed into vaporific form in flue between the deduster or the desulfurization reactor to the coal-burning boiler afterbody and contain Fe ³⁺, Fe ²⁺, Mn ²⁺, Ti ²⁺, Zn ²⁺The acid solution of one or more ion concentration 〉=20mg/L and PH≤5.5 wherein;

(2) the acid droplet that sprays into is caught flyash in the flue gas or sorbent particle thing and is formed liquid film on its surface, rapid evaporation along with moisture content in the liquid film, it is lower that pH value is tending towards, acidity is stronger, strengthened alkaline metal ions that particle contains and stripping and activation with transiting state metal ion of catalysed oxidn, and with flue gas in SO ₂Desulphurization reaction takes place;

(3) droplet evaporated before particle arrived the deduster inlet in the flue gas, and by the deduster collection and treatment, the effect that reduces dust specific resistance has been strengthened in the evaporation of acid droplet simultaneously to desulfurization product with dry state particle form.

Mechanism of the present invention is: (1) sprays into the acid solution droplet and makes it effectively catch flyash in flue gas or sorbent particle thing and form liquid film on its surface, under normally smoke evacuation condition of coal-fired flue-gas, solvent moisture content has precedence over the solute composition far away and evaporates rapidly in the acid droplet, along with water evaporates, that the PH of droplet, liquid film is tending towards is lower, acidity is stronger, test shows that the stripping reaction that under this condition alkali metal oxide and transiting state metal oxide take place is easy to carry out, so the alkaline metal ions Ca favourable to desulfurization ²⁺, Mg ²⁺, Na ⁺, K ⁺Deng, and to SO ₂Transiting state metal ion Fe with catalysed oxidn ³⁺, Fe ²⁺, Mn ²⁺, Ti ²⁺, Zn ²⁺All higher Deng stripping easily and dissolution rate and dissolution rate, and make these metallic elements be dissolved in the acid liquid film of particle performance with the active ion form, react with oxysulfide or nitrogen oxide in the flue gas, produce preferably desulfurized effect and subsidiary certain denitrification effect arranged; (2) because of the giving full play to and stronger sour environment of the catalysed oxidn of the transiting state metal ion that is dissolved with in the liquid film, make sulfide more with stable SO ₄ ^2-Form exists; (3) more H in the acid solution ⁺Existence, suppressed CO ₂Generation CO soluble in water ₃ ^2-, solubility reduces, and reduces because of CaCO ₃Generation and cause and SO ₂Contention Ca ²⁺Trend, make more Ca ²⁺Participate in desulphurization reaction and be used effectively; (4) before arriving the deduster inlet in the flue gas droplet and the surperficial liquid film of particle all evaporate substantially, and the acid composition that the evaporation of acid droplet and particle surface residue or absorption form, again flue gas is played the gather dust modified effect of reinforcement of the reduction dust specific resistance handled of electric cleaner that helps, final desulfurizing byproduct with the dry state particle by the deduster collection and treatment, thereby realize flue gas being carried out the desulfurization intensive treatment with acid solution spraying dry method.

As further improvement of the present invention, can also in the flue gas that sprays into acid solution and after acid droplet contacts 1 second with flue gas, in flue or desulfurization reactor, contain flyash or sorbent particle thing with the partial neutral or the alkaline solution of PH 〉=6 again, spray into droplet.By combination spraying realize behind the acid atomizing activating the adsorption desulfurize reaction with in, dissolving after the alkalescence spraying absorbs the optimum organization that desulphurization reaction combines and sprays, promptly can give full play to the desulfurized effect and the catalytic oxidation effect of desulfurizing agent in the metal oxide, improve the utilization rate of desulfurizing agent and catalytic oxidant, fully excavate the desulfurization potentiality of flyash/sorbent particle thing, in bringing into play again, alkaline solution dissolves preferably and absorb SO in the flue gas ₂And then with through acid droplet activated particles thing generation desulphurization reaction, have complementary advantages, further improve the utilization rate and the desulfurized effect of flyash or desulfurizing agent from two aspects.

The initial p H value of acid solution should not be too low, should not be lower than 3.0 usually, otherwise can aggravate the corrosion of system, corresponding requirement for anticorrosion meeting is tighter, if the anti-corrosion capability of system is stronger, then the initial p H value of acid solution can be lower, but still should not be too low, otherwise can influence SO ₂In solution, there is a form, is unfavorable for desulfurization on the contrary.

The solution of the preferred PH of described acid solution≤5 obtains the time of strong acidic condition more and contact the advantage that afterwards just can give full play to acid solution at the utmost point in the short time with flyash or sorbent particle thing in the hope of shortening by water evaporates.

Described acid solution is preferably sulfuric acid solution, because acid dew-point temperature is higher than the water dew point temperature far away in the flue gas under the normally smoke evacuation condition of fire coal, the degree of saturation that is to say moisture content in the flue gas is far below the degree of saturation based on the acid composition of oxysulfide, and the boiling point of sulfuric acid exceeds more than 230 ℃ than the boiling point of water, therefore, the evaporation rate of moisture content is higher than the evaporation rate of sulfuric acid composition far away in the acid droplet, after spraying into, make droplet effectively catch flyash in the flue gas or sorbent particle thing and form liquid film on its surface, solution is subjected to the flue gas heating, thereby moisture content evaporation rapidly makes the pH value of solution more and more lower, acidity is more and more stronger, helps the stripping of useful metal ion more; For hydrochloric acid, nitric acid acid solution, because hydrochloric acid and nitric acid volatilize relatively easily and boiling point is lower than the boiling point of water, make the acidity of flyash or sorbent particle surface liquid film be difficult for keeping, its effect will be more than adopting sulfuric acid solution poor.Another of use sulfuric acid is also advantageous in that the sulfuric acid solution of use can use by SO in a small amount of on-the-spot flue gas ₂By absorption and the dilute sulfuric acid produced of hydrolysis, or waste sulfuric acid solution or industrial sulphuric acid are formulated, can reach the effect of the treatment of wastes with processes of wastes against one another simultaneously again.

Described acid solution also can be to contain Fe ³⁺, Fe ²⁺, Mn ²⁺, Ti ²⁺, Zn ²⁺Wherein the acid solution of one or more ion concentration 〉=20mg/L and PH≤4.5 strengthens SO in the flue gas with the catalysed oxidn that utilizes the active metallic ion that contains in the acid solution ₂Catalytic oxidation, make acid solution spray into the back and contact with flue gas and can produce desulfurized effect preferably, prolong its effective desulfurization time.This acid solution can be by leaching from flyash or waste material or with the electrochemical method gained.

Described acid droplet and/or partially in, alkaline droplet size control target is preferably≤100 μ m, to reach preferably dispersion effect and to shorten evaporation time, and guarantee no process waste liquor generation from the spraying link to follow-up deduster inlet by the tissue of spray flow field, enter deduster with front evaporator fully, no liquid collecting, no open fire enters deduster.

Described acid solution spraying dry flue gas desulphurization and modified intensifying method can be that the flue gas that contains fine coal/sorbent particle thing is implemented acid spraying desulfurization/modified; Also can be when implementing acid spraying, spray into the dry desulfurizer particle, to obtain higher desulfuration efficiency.

Acid solution of the present invention spraying dry flue gas desulphurization intensifying method can also be that existing dry desulfurizing process is implemented the acid solution spraying, to strengthen former sulfur removal technology desulfurized effect, to improve sorbent utilization and to the degree of oxidation of desulfurization product.

Advantage of the present invention is:

1. activation effect is strong, gives full play to desulfurization potentiality and the desulfurization potentiality of desulfurizing agent and the catalysed oxidn of catalytic oxidation thing of flyash self.

The Fe that is rich in the flyash that acid solution more helps can be used in desulfurizing agent or the fly ash grain producing after the stripping, particularly coal combustion of the alkaline metal ions of desulfurization and transiting state metal ion ₂O ₃, MnO ₂, TiO ₂, ZnO etc. only o'clock could stripping Fe in PH≤5 ³⁺, Fe ²⁺, Mn ²⁺, Ti ²⁺, Zn ²⁺Deng to SO in the flue gas ₂With NOx the transiting state metal ion of obvious catalysed oxidn is arranged, and acidity is strong more, pH value is low more, temperature is high more, the dissolution rate of these ions and dissolution rate are also high more.Under normally smoke evacuation condition of coal-fired flue-gas, because the acid dew-point temperature of flue gas is higher than the water dew point temperature far away, generally at least about exceeding more than 50 ℃, the boiling point of sulfuric acid exceeds more than 230 ℃ approximately than the boiling point of water simultaneously, therefore after spraying into the formulated acid solution of sulfuric acid with vaporific form to flue gas, droplet is warming up to very soon and approaches 100 ℃, and moisture content wherein has precedence over the sulfuric acid evaporation far away, the acidity of residue droplet is more and more stronger, it is lower that pH value is tending towards, thereby the strong leaching condition that has possessed high temperature and low pH value has more alkaline metal ions and the stripping of transiting state metal ion and participates in removing SO in the flue gas ₂Reaction, strengthened activation effect, given full play to behind the coal combustion desulfurization potentiality of flying dust in the flue gas.And this effect can't realize under common partial neutral or alkaline spray condition.

2. improve degree of oxidation, reduce labile element calcium sulfite CaSO in the desulfurization product desulfurization product ₃Content, improve stable elements calcium sulfate CaSO ₄Ratio.

Low pH value environment is very favourable to the oxidation of sulphite, and test shows that oxidation rate sharply descends when pH value＞5, and the oxidation rate of pH value sulphite in≤5 scope is higher.Therefore acid solution particularly PH≤5 the acid solution spraying and moisture content progressively evaporating course extremely help to be stable sulfate, to reduce labile element CaSO in the desulfurization product significantly sulfite oxidation ₃Ratio.

3. improve the utilization rate of Ca base desulfurizer.

Acid droplet reduces CO greatly ₂Ca generates CaCO in a large amount of consumption desulfurizing agents ₃The degree of the Ca ion waste that causes makes more Ca ions and SO ₂Carry out desulphurization reaction, improve the utilization rate of Ca base absorbant.

4. improve desulfuration efficiency.

Owing to reduced the waste of Ca base desulfurizer, improved utilization rate, the desulfurization potentiality of having brought into play flyash simultaneously preferably are the catalysed oxidn of transiting state metal ion particularly, therefore, under identical sorbent consumption amount situation, can obtain higher desulfuration efficiency.

5. reduce the dust emission of follow-up electric cleaner outlet.

Owing to reduced doctor solution consumption, follow-up electric precipitation inlet dust content is reduced, acid atmosphere can reduce dust specific resistance significantly simultaneously, improves dust-collecting efficiency, thereby reduces the dust emission of electric precipitation outlet.

The mother liquor source of 6. preparing acid solution is easy to get.

SO in the coal-fired flue-gas ₂Because concentration is lower, be difficult to obtain the H of high concentration usually ₂SO ₄Recycled, but with the SO of flue gas ₂The technology that obtains 30% left and right sides concentration dilution heat of sulfuric acid by absorption method is very ripe, this solution is satisfied fully as the mother liquor that the present invention prepares PH≤5.5 acid solutions, and the flue gas consumption is also seldom, general only with boiler combustion produce exhaust gas volumn 0.2%～2% (specifically according to SO in the flue gas ₂Concentration is determined) the minute quantity flue gas just can meet the demands, so the on-the-spot mother liquor that very easily obtains the preparation acid solution.

7. the spraying system non-scaling is avoided the obstruction of pipeline and nozzle.

The alkalescence spraying is easy to cause the obstruction of spraying system fouling and nozzle, the then essentially no scale formation of acid spraying.

8. activate also effectively utilization because the composition quilt that can be used for desulfurization that contains in the flyash is abundant, and the also raising greatly of the utilization rate of desulfurizing agent, so can reduce the consumption of desulfurizing agent, obviously reduce desulphurization cost.

9. suit measures to local conditions the treatment of wastes with processes of wastes against one another.

Make full use of after the boiler combustion SO in the desulfurization effective ingredient of flyash and a small amount of flue gas in the flue gas ₂Realize or strengthen SO in the flue gas ₂Remove, and subsidiary certain effect that removes NOx is arranged, suit measures to local conditions, gather materials on the spot, the treatment of wastes with processes of wastes against one another has embodied resource, minimizing, innoxious recycling economy thought to a certain extent.

Description of drawings

Fig. 1 is for using SO in the flue gas ₂Produce the acid solution mother liquor and existing particle in the flue gas is implemented the schematic diagram of acid atomizing activating;

Fig. 2 is for using SO in the flue gas ₂Produce the acid solution mother liquor and when implementing acid atomizing activating, spray into the schematic diagram of dry state desulfurizing agent;

Fig. 3 is for waste sulfuric acid solution or industrial sulphuric acid being acid solution mother liquor and the schematic diagram of existing particle in the flue gas being implemented acid atomizing activating;

Fig. 4 is for waste sulfuric acid solution or industrial sulphuric acid being acid solution mother liquor and the schematic diagram that sprays into the dry state desulfurizing agent when implementing acid atomizing activating;

Among Fig. 1～Fig. 4:

1, not desulfurization or do not finish the flue gas of desulfurization;

2, relieving haperacidity flue gas;

3, general industry water or waste water;

4, adsorption desulfurize sulphuric acid plant;

5, acid solution;

6, flue or desulfurization reactor;

7, the ash-laden gas after the desulfurization;

8, deduster;

9, the flue gas behind the desulfurization dust separation;

10, desulfurizing byproduct;

11, the flue gas after the relieving haperacidity;

12, chimney;

13, dry state desulfurizing agent;

14, waste sulfuric acid solution or industrial sulphuric acid;

15, dilution buffer container;

The specific embodiment

Below in conjunction with the drawings and specific embodiments content of the present invention is further illustrated.

Embodiment 1:

As shown in Figure 1, desulfurization never or not finish the flue gas that takes a morsel in the flue gas 1 of desulfurization be relieving haperacidity flue gas 2, adsorption desulfurize sulphuric acid plant 4 by prior art and general industry water or waste water 3 utilize SO contained in the relieving haperacidity flue gas 2 ₂Obtain dilute sulfuric acid, and further be diluted to the acid solution 5 of PH=5, acid solution 5 is sprayed into the not desulfurization that contains flyash or sorbent particle thing or do not finish in the flue or desulfurization reactor 6 that the flue gas 1 of desulfurization passes through with vaporific form, fogdrop diameter≤50 μ m, make acid droplet can effectively catch particle in the flue gas by flow field rationalization, rapid evaporation along with moisture in the acid droplet, the acidity of particle surface liquid film is strong more, it is lower that PH is tending towards, make the desulfurization effective ingredient that contains in the particle activate stripping rapidly, and with flue gas in SO ₂Desulphurization reaction takes place, ash-laden gas 7 after the desulfurization is before arriving follow-up deduster 8 inlets, droplet evaporates substantially, dry state dust granules thing is become the desulfurizing byproduct 10 of dry state by deduster 8 separated and collected from flue gas, and the flue gas 11 of the flue gas 9 behind the desulfurization dust separation after relieving haperacidity normally discharges by chimney 12 simultaneously.

Cigarette temperature control after the spraying than acid dew-point temperature high 5 ℃ and more than, calculate spouting liquid and check acid dew-point temperature, correction spouting liquid according to the gentle exhaust gas volumn of the preceding cigarette of spraying with this, calculate the required acid amount of the acid solution of preparing PH≤5 also further according to SO in the flue gas according to required spouting liquid ₂Concentration and adsorption desulfurize sulphuric acid plant remove SO ₂Efficient (generally can reach more than 70%) can determine the relieving haperacidity exhaust gas volumn of required extraction.

Spraying system and spraying link should be considered certain anti-corrosion measure.

Embodiment 2:

As shown in Figure 2, on the basis of embodiment 1, spray into dry state desulfurizing agent 13, to obtain higher desulfuration efficiency to flue or desulfurization reactor 6.

Embodiment 3

As shown in Figure 3, preparation acid solution 5 required mother liquors directly dilute formulated with general industry water or waste water 3 by dilution buffer container 15 with waste sulfuric acid solution or industrial sulphuric acid 14 in the present embodiment, the pH value of acid solution 5 is 5.0, acid solution 5 is sprayed into the not desulfurization that contains flyash or sorbent particle thing or do not finish in the flue or desulfurization reactor 6 that the flue gas 1 of desulfurization passes through with vaporific form, fogdrop diameter≤50 μ m, make acid droplet can effectively catch particle in the flue gas by flow field rationalization, rapid evaporation along with moisture in the acid droplet, the acidity of particle surface liquid film is strong more, it is lower that PH is tending towards, make the desulfurization effective ingredient that contains in the particle activate stripping rapidly, and with flue gas in SO ₂Desulphurization reaction takes place, ash-laden gas 7 after the desulfurization is before arriving follow-up deduster 8 inlets, droplet evaporates substantially, and dry state dust granules thing is become the desulfurizing byproduct 10 of dry state by deduster 8 separated and collected from flue gas, and the flue gas 9 behind the desulfurization dust separation normally discharges by chimney 12 simultaneously.Also available waste nitric acid solution or industrial nitric acid replace waste sulfuric acid solution or industrial sulphuric acid 14, or replace waste sulfuric acid solution or industrial sulphuric acid 14 to remedy the situation of available waste sulfuric acid solution quantity not sufficient with the mixture of waste sulfuric acid solution and waste nitric acid solution.

Embodiment 4:

As shown in Figure 4, on the basis of embodiment 3, spray into dry state desulfurizing agent 13 to flue or desulfurization reactor 6, obtaining higher desulfuration efficiency, identical among other parts and the embodiment 3.

Embodiment 5:

On embodiment 1～4 basis, acid solution 5 is with flyash or waste material leaching, promptly contains Fe with acid solution immersion flyash or other ³⁺, Fe ²⁺, Mn ²⁺, Zn ²⁺, Ti ²⁺In other waste material of inorganic salts or oxide, or contain Fe with what the electrochemical means electrolysis obtained ³⁺, Fe ²⁺, Mn ²⁺, Zn ²⁺, Ti ²⁺Wherein the acid solution of one or more ion concentration 〉=20mg/L and PH=4.0 sprays into by the mode among the embodiment 1～4, to strengthen SO in the flue gas ₂Catalysed oxidn, and subsidiary certain NO that removes arranged _xEffect.

Embodiment 6

In embodiment 1～5, acidity is sprayed and after acid droplet contacts 1 second with flue gas, is sprayed into the partial neutral or the alkaline solution of PH 〉=6 again to the back segment of flue or desulfurization reactor 6.After the acid spraying, along with the rapid evaporation of moisture in the acid droplet, the acidity of particle surface liquid film is strong more, and it is lower that PH is tending towards, and makes the desulfurization effective ingredient that contains in the particle activate stripping rapidly; Partial neutral or alkaline solution spraying then are more prone to, absorb rapidly dissolving SO ₂And then react with the alkaline metal ions and the transiting state metal ion of acid atomizing activating stripping, to obtain the higher desulfuration effect, ash-laden gas 7 after desulfurization droplet before arriving follow-up deduster 8 inlets evaporates substantially and the dry state dust separation that contains in flue gas by deduster 8 is gathered into desulfurizing byproduct 10, and the flue gas behind the desulfurization dust separation 9 passes through chimney 12 and normally discharges simultaneously.

Claims

1, a kind of acid solution spraying dry flue gas desulphurization processing method is characterized in that this method comprises following process:

2, acid solution as claimed in claim 1 spraying dry flue gas desulphurization processing method is characterized in that: spray into droplet in acid solution spraying and the flue gas that contains flyash or sorbent particle thing with the partial neutral or the alkaline solution of PH 〉=6 in flue or desulfurization reactor again after acid droplet contacts 1 second with flue gas.

3, acid solution spraying dry flue gas desulphurization processing method as claimed in claim 1 or 2, it is characterized in that: described acid solution is the acid solution of PH≤5.

4, acid solution spraying dry flue gas desulphurization processing method as claimed in claim 1 or 2, it is characterized in that: described acid solution is to contain Fe ³⁺, Fe ²⁺, Mn ²⁺, Ti ²⁺, Zn ²⁺The solution of wherein one or more ion concentration 〉=20mg/L, and PH≤4.5.

5, acid solution spraying dry flue gas desulphurization processing method as claimed in claim 1 or 2, it is characterized in that: described acid solution is a sulfuric acid solution.

6, acid solution spraying dry flue gas desulphurization processing method as claimed in claim 1 or 2, it is characterized in that: described droplet size is≤100 μ m, and produce to the no process waste liquor of follow-up deduster inlet from the spraying link, droplet evaporates abundant, no liquid collecting before entering deduster, and no open fire enters deduster.

7, acid solution spraying dry flue gas desulphurization processing method as claimed in claim 1 or 2 is characterized in that: when implementing acid spraying, also spray into the dry desulfurizer particle.