WO2008100317A1 - Épurateur pour la désulfuration de courants gazeux - Google Patents

Épurateur pour la désulfuration de courants gazeux Download PDF

Info

Publication number
WO2008100317A1
WO2008100317A1 PCT/US2007/062339 US2007062339W WO2008100317A1 WO 2008100317 A1 WO2008100317 A1 WO 2008100317A1 US 2007062339 W US2007062339 W US 2007062339W WO 2008100317 A1 WO2008100317 A1 WO 2008100317A1
Authority
WO
WIPO (PCT)
Prior art keywords
gas
liquid
scrubbing
gas stream
set forth
Prior art date
Application number
PCT/US2007/062339
Other languages
English (en)
Inventor
Steven F. Meyer
Original Assignee
Mecs, Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Mecs, Inc. filed Critical Mecs, Inc.
Priority to PCT/US2007/062339 priority Critical patent/WO2008100317A1/fr
Publication of WO2008100317A1 publication Critical patent/WO2008100317A1/fr

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/46—Removing components of defined structure
    • B01D53/48—Sulfur compounds
    • B01D53/50—Sulfur oxides
    • B01D53/501—Sulfur oxides by treating the gases with a solution or a suspension of an alkali or earth-alkali or ammonium compound

Definitions

  • the present invention relates generally to treatment of gaseous industrial process streams for the selective removal of sulfur-containing species, and particularly the removal of sulfur dioxide (SO 2 ) , sulfur trioxide (SO3) , H 2 SO 4 and mixtures thereof.
  • SO 2 sulfur dioxide
  • SO3 sulfur trioxide
  • H 2 SO 4 hydrogen fluoride
  • the disclosed invention is useful in removing sulfuric acid mists and/or reducing the opacity exhibited by the treated gas stream.
  • Such processes include, but are not limited to, for example, fossil fuel-fired power plants, natural gas treatment plants, refineries (e.g., fluid catalytic cracking (FCC) units) , sulfur recovery units (SRUs) , sulfuric acid plants, metal roasting operations, cement kilns and synthesis gas plants.
  • FCC fluid catalytic cracking
  • SRUs sulfur recovery units
  • a wet scrubber system is one type of flue gas desulfurization process employed to remove sulfur-containing compounds from such process gas streams.
  • the sulfur compounds present are typically first oxidized to SO 2 and the SO 2 then selectively removed by contacting the gas with an aqueous solution containing an alkaline or basic reagent circulating in a gas-liquid contacting device.
  • Typical reagents include, for example, alkali metal and alkaline earth metal hydroxides, carbonates, bicarbonates, lime (CaO) , hydrated or slaked lime (Ca(OH) 2 ) limestone (CaCOs), and waste streams containing these compounds including, for example, cement kiln dust and soda ash.
  • the SO 2 in the gas is absorbed or dissolved into the scrubbing solution where it reacts with the reagent.
  • the resulting liquid solution containing the reaction products can be purged from the system for disposal or regenerated for recycle.
  • Wet gas scrubbing systems can operate over a wide range of feed conditions, as is often found in refineries and gas plants.
  • CaOH is an example of a reagent commonly used to remove SO 2 in wet scrubbing operations.
  • caustic removes SO 2 according to the following reactions that involve the formation of sodium sulfite (Na 2 SC>3) and/or bisulfite (NaHSO 3 ) :
  • sodium bisulfite in accordance with equation (4) is dependent upon the temperature and total dissolved solids concentration in the scrubbing solution and occurs primarily when the pH of the scrubbing solution is below about 7.
  • the sodium sulfite and bisulfite salts formed in the above reactions are typically further oxidized to sodium sulfate in order to reduce the chemical oxygen demand of the liquid scrubber stream discharged from the system to an acceptable level.
  • Other scrubbing reagents exhibit a similar chemistry.
  • gas streams containing SO 2 also contain SO 3 .
  • Gaseous streams containing SO 3 can create difficulties in the design and operation of a wet scrubber system.
  • SO 3 may be present in the process stream from the base process from which it originates or may be produced during subsequent incineration of the process stream to convert sulfur compounds to SO 2 upstream of the wet scrubber operation.
  • SO3 contacts and reacts with water in the scrubber to form sulfuric acid that can condense and form a sulfuric acid mist.
  • Sulfuric acid mist formed in this fashion exhibits a very small, submicron droplet size, that renders it difficult to remove from the gas stream.
  • mist eliminators collect, coalesce and drain mist droplets entrained in the gas stream exiting the scrubber before it is vented to the atmosphere.
  • mist eliminators add to the cost of a wet scrubber system through increased initial capital cost and increased energy consumption due to the pressure drop associated with the mist eliminator.
  • the present invention is directed to a process for removing at least one sulfur specie selected from the group consisting of SO 3 , H 2 SO 4 and mixtures thereof from a gas stream.
  • the process comprises contacting the gas stream in at least one scrubbing zone of a gas-liquid contacting device with a scrubbing liquid comprising an aqueous solution containing a basic reagent and having a pH of at least about 8.5.
  • SO 3 and/or H 2 SO 4 is absorbed and reacted with the basic reagent in the liquid phase to produce a treated gas stream depleted in the sulfur specie (s) and a spent scrubbing solution comprising the liquid phase reaction product.
  • the gas stream to be treated comprises SO 2
  • the process further comprises simultaneous removal of SO 2 from the gas stream along with S03 and/or H 2 SO 4 .
  • the SO 2 is also absorbed and reacted with the basic reagent in the liquid phase such that the treated gas stream produced is likewise depleted in SO2 and the spent scrubbing solution comprises the liquid phase reaction product of the basic reagent and SO 2 .
  • Fig. 1 shows a plot of the theoretical Na + ion concentration versus pH in a representative aqueous scrubbing solution containing NaOH as the basic reagent as determined at a temperature of about 71°C using electrolyte simulation software.
  • FIG. 2 is a schematic diagram of a wet scrubber system for removing sulfur-containing species and particulate impurities from a gaseous stream in accordance with a preferred embodiment of the present invention utilizing a reverse jet scrubber as a gas-liquid contacting device .
  • a wet scrubber system has been discovered that provides for effective, removal of at least one sulfur specie selected from the group consisting of SO3, H 2 SO 4 and mixtures thereof from a gaseous stream.
  • the removal of SO 3 and/or H 2 SO 4 from gaseous streams in a wet scrubber system employing a scrubbing liquid or medium comprising an aqueous solution of a basic reagent is enhanced by maintaining an elevated pH in the scrubbing liquid contacted with the gaseous stream.
  • the wet scrubber system of the present invention can be used to simultaneously remove SO 2 and at least one other sulfur specie selected from the group consisting of SO 3 , H 2 SO 4 and mixtures thereof from a gaseous stream.
  • Non-limiting examples of the types of sulfur- containing process gas streams that may be treated in the practice of the present invention include those issuing from fossil fuel-fired power plants or other flue gases generated in the combustion of sulfurous fuels, natural gas treatment plants, fluid catalytic cracking (FCC) units, cokers, calciners, incinerators, sulfur recovery units (SRUs) , the sulfur trioxide absorber of a contact sulfuric acid plant, metal roasting operations, synthesis gas plants, cement kilns, and the incinerator of a Claus plant.
  • FCC fluid catalytic cracking
  • SRUs sulfur recovery units
  • the gaseous streams may contain sulfur oxides (SO 2 and SO 3 ) hydrogen sulfide (H 2 S) , carbon disulfide (CS 2 ) , dimethyl sulfide, carbonyl sulfide as well as other sulfur-containing compounds generated in the base process from which it originates.
  • sulfur oxides and other sulfur compounds the gaseous stream to be treated may also contain carbon dioxide, carbon monoxide, water vapor, oxygen, nitrogen and other compounds.
  • the sulfur content may first be oxidized to convert the sulfur compounds present to sulfur oxides, primarily to SO 2 .
  • the gas stream may be fed to a forced draft thermal incinerator or similar apparatus along with sufficient combustion oxygen (e.g., air) and a fuel source for the burners and maintained at a sufficiently high temperature for a given residence time to oxidize the sulfur compounds present.
  • sufficient combustion oxygen e.g., air
  • a fuel source for the burners and maintained at a sufficiently high temperature for a given residence time to oxidize the sulfur compounds present.
  • the gas stream may also be conditioned prior to being introduced into the wet scrubber system, for example, to cool the gas and maintain the desired operating temperature in the scrubber system and/or remove entrained particulate impurities from the gas.
  • Conditioning can include, for example, indirect heat exchange, quenching through contact with a countercurrent flow of water (e.g., by passing the gaseous stream through a reverse jet scrubber of the type sold by MECS, Inc. (Chesterfield, Missouri U.S.A. 63017) under the trademark DYNAWAVE) and removal of particulate impurities from the gas stream in an electrostatic precipitator.
  • composition and temperature of the gaseous stream contacted with the aqueous scrubbing liquid will vary depending upon its origin and any pre-treatment or conditioning measures employed prior to its introduction into the gas-liquid contacting device of the wet scrubber system.
  • the temperature of the gas introduced into the gas-liquid contacting device will be less than about 1,400 0 C, typically from about 100 0 C to about 320 0 C.
  • the gaseous stream introduced into the gas-liquid contacting device will typically comprise, on a dry basis, at least about 500 ppmv SO 2 and up to about 100,000 ppmv SO 2 and at least one other sulfur specie selected from SO3, H 2 SO 4 and mixtures thereof along with various other components such as nitrogen, oxygen, carbon dioxide, carbon monoxide and/or other sulfur compounds.
  • the present invention is also useful in the removal SO3 and/or H 2 SO 4 from gas streams independent of the SO 2 content of the gas and does not require the simultaneous removal of SO 2 from the gas stream.
  • SO2 may be preferentially removed from the gas stream prior to application of the process of this invention such that the gas to be treated comprises a sulfur specie selected from SO 3 , H 2 SO 4 and mixtures thereof without significant SO 2 content.
  • the gas stream contacted with the aqueous scrubbing liquid contains SO 3 and/or H 2 SO 4 at concentrations that might otherwise result in the formation of appreciable quantities of sulfuric acid mist and opacity problems in the treated gas stream exiting the wet scrubber system.
  • the gaseous stream introduced into the gas- liquid contacting device will typically comprise, on a dry basis, a concentration of SO 3 and/or H 2 SO 4 (typically reported as H 2 SO 4 ) of at least about 5 ppmv and up to about 1,000 ppmv, and more typically, from about 10 ppmv to about 200 ppmv, or from about 10 ppmv to about 50 ppmv.
  • a concentration of SO 3 and/or H 2 SO 4 typically reported as H 2 SO 4
  • At least one sulfur specie selected from the group consisting of SO 3 , H 2 SO 4 and mixtures thereof are selectively removed from the gaseous stream.
  • the gaseous stream is contacted with a scrubbing liquid in a scrubbing zone of a suitable gas-liquid contacting device of the wet scrubber system.
  • the scrubbing liquid comprises an aqueous solution containing a basic reagent.
  • aqueous scrubbing liquid absorbs the SO 3 and/or H 2 SO 4 along with any SO 2 present in the gaseous stream into the scrubbing liquid where these components then react with the basic reagent in the liquid phase to produce a treated gas stream depleted in SO 3 and/or H 2 SO 4 and optionally SO 2 as well if present in the gas stream to be treated, and a spent scrubbing solution comprising the liquid phase reaction products.
  • Other components of the gas stream largely pass through the scrubbing zone and are retained in the treated gas stream. Additional basic reagent is added to the spent scrubbing solution to regenerate the scrubbing liquid and the regenerated scrubbing liquid is reintroduced into the scrubbing zone into contact with the gas stream.
  • Suitable basic reagents for use in the practice of the present invention include, for example, but are not limited to, sodium hydroxide, sodium carbonate, sodium bicarbonate, calcium oxide or lime (CaO) , calcium hydroxide or hydrated lime (Ca(OH) 2 ), calcium carbonate or limestone (CaCO 3 ) , calcium bicarbonate, potassium oxide, potassium hydroxide, potassium carbonate, potassium bicarbonate, magnesium oxide, magnesium hydroxide, magnesium carbonate, magnesium bicarbonate, zinc oxide, zinc hydroxide, zinc carbonate, zinc bicarbonate, ammonia, and ammonium hydroxide.
  • the basic reagent can also be suitably derived from materials containing these reagents, such as cement kiln dust and soda ash.
  • the selection of the basic reagent to employ in the aqueous scrubbing zone is based upon a number of factors including, for example, initial capital cost associated with the wet scrubber system, operating cost, cost of the reagent and the composition of the gaseous stream to be treated.
  • the basic reagent used in the process of the present invention comprises sodium hydroxide or caustic (NaOH) or lime (CaO) .
  • the basic reagent comprises NaOH.
  • NaOH sodium hydroxide or caustic
  • CaO lime
  • the basic reagent comprises NaOH.
  • the use of NaOH as the basic reagent in the wet scrubbing operation provides relatively fast reaction times with the absorbed sulfur species and, subsequently, relatively high removal efficiencies. Also, use of NaOH allows for simpler scrubber design and operation because the sulfur-binding reactants are readily soluble in the aqueous scrubbing liquid.
  • the removal of SO 3 and/or H 2 SO 4 from the gaseous stream contacted with the aqueous scrubbing liquid comprising the basic reagent is enhanced by maintaining an elevated pH in the scrubbing liquid contacted with the gaseous stream.
  • the pH of the aqueous scrubbing liquid is controlled by the addition of basic reagent to the spent scrubbing solution used to regenerate the scrubbing liquid prior to recycling the regenerated liquid to the scrubbing zone of the gas-liquid contacting device.
  • the pH of the aqueous scrubbing liquid contacted with the gaseous stream in the scrubbing zone should be maximized in order to effectively remove SO 3 and/or H 2 SO 4 from the gaseous stream, while the pH of the spent scrubbing solution collected in the scrubber sump should be minimized in order to avoid excessive consumption of reagent.
  • the removal of SO 3 and/or H 2 SO 4 is enhanced at relatively high pH . Therefore, in accordance with the present invention the scrubbing liquid contacted with the gas stream in the scrubbing zone of the gas-liquid contacting device generally has a pH of at least about 8.5, preferably at least about 9, and even more preferably at least about 9.5.
  • the pH of the aqueous scrubbing liquid contacted with the gas stream in the scrubbing zone of the gas-liquid contacting device should generally be increased as the concentration of SO 3 and/or H 2 SO 4 as well as any SO 2 in the gas to be treated increases.
  • the scrubbing liquid contacted with the gas stream in the scrubbing zone of the gas-liquid contacting device has a pH of at least about 9.75, at least about 10, at least about 10.25, at least about 10.5, at least about 10.75, more preferably at least about 11, at least about 11.25, at least about 11.5, at least about 11.75, even more preferably at least about 12 or higher when the incoming gas stream to be treated contains appreciable quantities of these sulfur species and/or when a higher removal efficiency is required.
  • the pH of the spent aqueous scrubbing liquid collected from the scrubbing zone of the gas-liquid contacting device is generally maintained from about 6 to about 12, preferably less than about 10, more preferably less than about 9, and even more preferably less than about 8.5.
  • the pH differential between the regenerated scrubbing liquid contacting the gas to be treated in the scrubbing zone of the gas-liquid contacting device and the collected scrubbing liquid from the scrubbing zone is dependent upon a variety of factors including the composition of the incoming gas and the concentration of SO 2 , SO 3 and/or H 2 SO 4 .
  • Fig. 1 shows a plot of the theoretical Na + ion concentration versus pH in a representative aqueous scrubbing solution containing NaOH as the basic reagent as determined at a temperature of about 71°C using electrolyte simulation software. As shown in Fig.
  • the concentration of sodium ion (Na + ) in the aqueous scrubbing solution increases sharply at a pH of at least about 9.
  • absorbed SO3 gas and/or H 2 SO 4 in the liquid phase is much more likely to react with the basic reagent and become bound in a more soluble reaction product (e.g., sodium sulfate (Na 2 SO 4 ) ) during a given residence time within the scrubbing zone and allow more SO3 gas and/or H 2 SO 4 to be absorbed in the liquid phase.
  • the viscosity and/or surface tension characteristics of the scrubbing liquid are more favorable for rapid absorption of SO 3 gas and/or H 2 SO 4 into the scrubbing liquid.
  • the flow of the gas stream to be treated and the aqueous scrubbing liquid through the scrubbing zone of the gas-liquid contacting device may be co-current or countercurrent .
  • the stream is preferably initially contacted countercurrently with the scrubbing liquid in the gas-liquid contacting device.
  • gas-liquid contacting devices may be used in the wet scrubber system including, for example, towers containing means for promoting mass transfer between the gas and liquid phases (e.g., a bed of random packing such as saddles or rings, structured packing or trays) .
  • the incoming gas stream is preferably introduced through an inlet near the bottom of the tower and the aqueous scrubbing liquid is introduced through a liquid inlet near the top of the tower and distributed over a bed of packing or other means for promoting mass transfer.
  • the spent scrubbing solution comprising the liquid phase reaction products collects in the bottom or sump of the tower and the treated gas stream is removed from an outlet near the top of the tower.
  • the amount of scrubbing liquid circulating through the gas-liquid contacting device versus the flowrate of the incoming gaseous stream is referred to as the liquid to gas volumetric ratio, or L/G ratio, and is typically expressed in gallons per minute (gpm) divided by the gas flow through the device in actual cubic feet per minute (acfm) , divided by 1000.
  • the L/G ratio is a key parameter for the scrubbing operation in accordance with the present invention and is preferably sufficiently high to fully quench the incoming gaseous stream (if necessary) and to absorb the SO 2 and other components of the stream gas without unduly suppressing the pH of the aqueous scrubbing solution. In general, higher L/G ratios will provide higher SO 2 removal efficiencies.
  • the removal of SO3 and/or H 2 SO 4 from the gaseous stream and the removal of sulfuric acid mist may be further enhanced by operating the gas-liquid contacting device at high L/G ratios.
  • the gas-liquid contacting device in which the gaseous stream contacts the aqueous scrubbing liquid is preferably capable of operating at high L/G ratios and, in a particularly preferred embodiment, comprises a reverse jet scrubber of the type disclosed in U.S. Patent No. 3,803,805 and sold under the trademark DYNAWAVE by MECS, Inc. (Chesterfield, Missouri U.S.A. 63017). Reverse jet scrubbers are particularly suited for effective separation and removal of particulate and gaseous components from gas streams .
  • the wet scrubber system of Fig. 2 comprises a gas-liquid disengagement vessel 9 with a sump 1 in which the spent aqueous scrubbing solution is collected, a vertical inlet gas duct 2 connected with the vessel through which the gaseous stream is introduced and an outlet gas duct 3 running out of the vessel through which the treated gas stream is discharged.
  • At least one reverse jet nozzle 4 is disposed and arranged within the inlet gas duct 2 for directing a flow of the aqueous scrubbing liquid countercurrent to the direction of the incoming gas flowing vertically downward into the vessel.
  • a pump 5 transfers scrubbing liquid from the sump 1 to the nozzle (s) 4.
  • the wet scrubber system is constructed of materials that are resistant to corrosion caused by continual contact with acidic gases and the basic reagent. If used to treat the gaseous effluent from a Claus sulfur recovery unit, it is preferred that the inlet gas duct 2 be made from a high alloy material, such as for example, AL6XN or DUPLEX 2205.
  • the gas-liquid disengagement vessel 9 can be suitably constructed from 316 stainless steel because of the low level of chloride.
  • use of caustic with higher concentrations of chlorides e.g., diaphragm grade caustic
  • may require the use of more corrosion resistant materials such as DUPLEX 2205 or fiberglass reinforced plastic (FRP) in the construction of the vessel.
  • the reverse jet nozzles 4 are non-atomizing and can operate at relatively low liquid pressures and are manufactured from abrasion resistant material.
  • the wet scrubber system comprises two reverse jet nozzles 4 in series in the inlet gas duct 2.
  • the scrubbing zone(s) or contacting stages in which the countercurrent flows of gas and scrubbing liquid initially collide comprise a "froth zone" 7 and 8, respectively.
  • the froth zone(s) generated by reverse jet scrubbers are characterized by intense mixing and mass transfer from the gas to the liquid phase and operate to simultaneously quench the incoming gas, absorb SO 2 and SO3 and/or H 2 SO 4 in the scrubbing liquid and remove entrained particulates .
  • the flow of gas and liquid exiting the froth zone is co-current, vertically downward and generally along the walls of inlet gas duct 2.
  • the incoming gaseous stream is initially contacted with the scrubbing liquid and provides rapid quenching of the gas stream and an initial absorption of components of the gas stream into the scrubbing liquid.
  • the gas typically exits the first froth zone 7 at its adiabatic saturation temperature (generally less than about 100 0 C) and passes further down inlet gas duct 2 where it again contacts a countercurrent flow of the scrubbing liquid in the second froth zone 8 wherein further absorption of components of the gas stream occurs.
  • adiabatic saturation temperature generally less than about 100 0 C
  • the wet scrubber system of the present invention illustrated in Fig. 2 is typically operated at an overall liquid to gas ratio (L/G) in the range of from about 35 to about 600 gpm of liquid per 1000 acfm of gas.
  • Each reverse jet scrubbing zone or contacting stage of the scrubber system is preferably operated at an L/G ratio in the range of from about 40 to about 200 gpm of liquid per 1000 acfm of gas, more preferably from about 60 to about 200 gpm of liquid per 1000 acfm of gas, even more preferably from about 80 to about 200 gpm of liquid per 1000 acfm of gas.
  • Gas exiting the second froth zone 8 is passed into gas-liquid disengagement vessel 9 where it reverses vertical direction resulting in separation of the spent scrubbing solution from the treated gas stream depleted in SO3 and/or H 2 SO 4 and optionally SO 2 .
  • the spent aqueous scrubbing solution collects in sump 1 and comprises excess reagent, reaction products [sodium sulfite (Na 2 SOs), sodium sulfate (Na 2 SO 4 ) and/or sodium bisulfite (NaHSOs) ] and solid particulates.
  • the treated gas stream optionally passes through a gas/liquid separation device 10 (e.g., a vertical flow chevron demister) to remove larger entrained liquid droplets before it enters the outlet gas duct 3 and is discharged from the vessel.
  • the outlet gas duct 3 can be connected to further gas processing equipment or vented to the atmosphere.
  • it is unnecessary to provide for downstream treatment to remove finer liquid mist particles e.g., conventional fiber bed mist eliminators installed within gas-liquid disengagement vessel 9) since the wet scrubbing process in accordance with the present invention is capable of adequately removing sulfuric acid mists and/or sufficiently reducing the opacity exhibited by the treated gas stream.
  • the treated gas stream may optionally be subjected to additional mist elimination treatment without departing from the scope of the present invention.
  • gas-liquid disengagement vessel 9 of the wet scrubber system may optionally include a further gas-liquid contacting stage 14 comprising a bed of packing material (e.g., 5 cm nominal diameter ceramic saddles or other types of mass transfer packing) , a froth column or similar means for promoting mass transfer between the gas and liquid phases.
  • the scrubber system is further equipped with a distributor 15 to supply scrubbing liquid to the further gas-liquid contacting stage 14. Treated gas flows upwardly through contacting stage 14 countercurrent to the flow of descending scrubbing liquid, wherein additional SO2 and SO3 and/or H 2 SO 4 are absorbed and reacted in the liquid phase.
  • the pH of the spent scrubbing solution collected in sump 1 decreases as NaOH is consumed in the reaction with absorbed SO 2 and SO3 and/or H 2 SO 4 .
  • additional NaOH is added to the spent scrubbing solution to regenerate the scrubbing liquid to the desired pH before it is reintroduced into the scrubbing zone(s).
  • Addition of basic reagent to the circulating scrubbing liquid and pH control can be achieved in various ways. For example, as shown in Fig.
  • NaOH may be metered into the wet scrubber system through reagent feed line 6 into the circulation line connecting the sump with reverse jet nozzles 4 in response to the measured pH of the circulating liquid downstream of the reagent feed line and upstream of the nozzles.
  • the pH of the spent scrubbing solution in the sump is usually lower than the pH of the regenerated scrubbing liquid reintroduced into the scrubbing zone(s), the magnitude of the pH differential being dependent upon the composition of the incoming gas, the L/G ratio in the reverse jet scrubber and other operating parameters .
  • pH control can be attained by measuring the pH at various other locations in the wet scrubber system, such as the pH of the spent scrubbing solution collected in the sump, and additional NaOH can be introduced directly into the sump.
  • the amount of make-up water can be controlled to respond to the liquid level in sump 1.
  • Oxygen, hydrogen peroxide or other suitable oxidizing agent may be introduced into sump 1 through an oxidant inlet 12 to further oxidize the reaction products in the spent scrubbing solution resulting from the reaction between the reagent and absorbed SO 2 and SO3 and/or H 2 SO 4 (e.g., Na 2 SOs) .
  • Oxidation treatment may be used to stabilize the reaction products and reduce the chemical oxygen demand of the spent scrubbing solution to a level acceptable by wastewater treatment facilities.
  • the reaction products (preferably in an oxidized state) and particulate contaminate captured in the spent solution may be removed from the wet scrubber system through purge stream 11.
  • the amount of liquid purged can be controlled in response to changes in particulate solids content. For example, it is preferred that liquid be purged when the spent scrubbing solution in the sump reaches a specific gravity of from about 1.07 to about 1.20.
  • the wet scrubber system operated in accordance with the present invention provides for effective, simultaneous removal of SO 2 and SO3 and/or H 2 SO 4 from a gaseous stream.
  • the proportion of SO 2 and SO 3 and/or H 2 SO 4 removed from the gaseous stream and the concentrations of these components in the treated gas stream will depend upon the composition of the incoming gas and the design parameters established for the wet scrubber system. Typically, at least about 90% and up to about 99% or greater of SO 2 and at least about 50% of SO 3 and/or H 2 SO 4 contained in the gaseous effluent may be removed.
  • the concentration of H 2 SO 4 in the treated gas stream may be reduced to an extent such that the treated gas stream does not exhibit a visible plume. More particularly, the concentration of H 2 SO 4 in the treated gas stream may be reduced such that the opacity of the treated gas stream is less than about 20%, more preferably, less than about 10% (as determined using U.S. EPA Method 9) .
  • a tailgas stream of about 13,500 acfm containing, on a dry basis, about 7,100 ppmv SO 2 and about 20 ppmv acid vapor (SO 3 and/or H 2 SO 4 ) was treated in accordance with the present invention.
  • the wet scrubber system utilized was similar to that shown in Fig. 2 and included two reverse jet (DYNAWAVE) contacting stages and a subsequent packed column contacting stage.
  • the reverse jet stages were each operated at an L/G ratio of about 100 gpm of liquid per 1000 acfm of gas.
  • the aqueous scrubbing solution comprising an aqueous caustic solution of NaOH was collected in the sump of the wet scrubber system.
  • the sump liquid was maintained at a pH range of from about 6.5 to about 10.5.
  • Significant removal of SO 3 and/or H 2 SO 4 from the tailgas was observed during intervals when the pH of the spent scrubbing liquid collected in the sump of the wet scrubber system was in excess of about 9, corresponding to an estimated pH of the regenerated scrubbing liquid fed to the reverse jet contacting stages of at least about 12.
  • the treated gas from the wet scrubber outlet was found to contain about 1 ppmv dry basis SO 2 and less than about 6 ppmv dry basis H 2 SO 4 .
  • the removal efficiency for SO 2 was greater than 99.9% and about

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Health & Medical Sciences (AREA)
  • Biomedical Technology (AREA)
  • Environmental & Geological Engineering (AREA)
  • Analytical Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Treating Waste Gases (AREA)
  • Gas Separation By Absorption (AREA)

Abstract

L'invention concerne un processus d'épuration par voie humide pour le traitement de courants gazeux de traitement industriel contenant du soufre pour l'élimination sélective des espèces contenant du soufre, notamment l'élimination simultanée de dioxyde de soufre (SO2) et d'une espèce de soufre choisie parmi le trioxyde de soufre (SO3), H2SO4 et des mélanges de ceux-ci. Le processus est utile dans l'élimination des brouillards d'acide sulfurique et/ou la réduction de l'opacité présentée par le courant gazeux traité.
PCT/US2007/062339 2007-02-16 2007-02-16 Épurateur pour la désulfuration de courants gazeux WO2008100317A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/US2007/062339 WO2008100317A1 (fr) 2007-02-16 2007-02-16 Épurateur pour la désulfuration de courants gazeux

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US2007/062339 WO2008100317A1 (fr) 2007-02-16 2007-02-16 Épurateur pour la désulfuration de courants gazeux

Publications (1)

Publication Number Publication Date
WO2008100317A1 true WO2008100317A1 (fr) 2008-08-21

Family

ID=38659812

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2007/062339 WO2008100317A1 (fr) 2007-02-16 2007-02-16 Épurateur pour la désulfuration de courants gazeux

Country Status (1)

Country Link
WO (1) WO2008100317A1 (fr)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101915714A (zh) * 2010-08-26 2010-12-15 河南电力试验研究院 一种判断不同石膏脱水性能的方法
CN103349901A (zh) * 2013-06-14 2013-10-16 中国恩菲工程技术有限公司 烟气处理方法及其设备
EP3175907A1 (fr) 2015-12-04 2017-06-07 Lab Sa Installation et procédé d'épuration des fumées d'échappement d'un moteur d'un navire marin
CN107281924A (zh) * 2017-08-09 2017-10-24 安徽理工大学 一种改进的氨法脱硫工艺及系统
CN108176202A (zh) * 2017-12-26 2018-06-19 北京亘源环保有限公司 一种脱硫吸附剂的制备方法及应用
KR101911309B1 (ko) * 2017-05-15 2018-10-24 (주)엔코아네트웍스 폐 황산화물 가스를 이용한 황산나트륨 제조 장치
WO2018218152A1 (fr) * 2017-05-25 2018-11-29 Fisher Agc, Llc Procédés de capture de composés gazeux contenant du soufre à partir d'un gaz naturel contenant du sulfure d'hydrogène
US10315149B2 (en) 2014-01-07 2019-06-11 Mecs Inc Gas inlet system for wet gas scrubber
WO2020014015A1 (fr) 2018-07-11 2020-01-16 Mecs Inc Suppression de panache à l'aide d'échangeurs de chaleur à coque et tubes à thermosiphon
US11395987B2 (en) 2019-10-17 2022-07-26 Veolia North America Regeneration Services, Llc Scrubber system improvement for sulfur containing gas streams
CN114832610A (zh) * 2022-04-02 2022-08-02 徐州宏阳新材料科技股份有限公司 一种竖炉烟气的深度脱硫方法

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3832444A (en) * 1972-05-18 1974-08-27 Trw Inc Recovery of so{11 {11 and so{11 {11 from flue gases
US3944650A (en) * 1972-03-27 1976-03-16 Asahi Glass Company Ltd. Process for removing oxides of sulfur, dust and mist from combustion waste gas
GB1596809A (en) * 1977-03-29 1981-09-03 Kureha Chemical Ind Co Ltd Process for treatment of exhaust gas
US4903756A (en) * 1985-06-26 1990-02-27 Monro Richard J Heat generator
US6060030A (en) * 1998-04-20 2000-05-09 Schwab; James J. Detached plume abatement method
US20030143140A1 (en) * 2002-01-29 2003-07-31 Shuen-Cheng Hwang Process for the removal of impurities from gas streams

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3944650A (en) * 1972-03-27 1976-03-16 Asahi Glass Company Ltd. Process for removing oxides of sulfur, dust and mist from combustion waste gas
US3832444A (en) * 1972-05-18 1974-08-27 Trw Inc Recovery of so{11 {11 and so{11 {11 from flue gases
GB1596809A (en) * 1977-03-29 1981-09-03 Kureha Chemical Ind Co Ltd Process for treatment of exhaust gas
US4903756A (en) * 1985-06-26 1990-02-27 Monro Richard J Heat generator
US6060030A (en) * 1998-04-20 2000-05-09 Schwab; James J. Detached plume abatement method
US20030143140A1 (en) * 2002-01-29 2003-07-31 Shuen-Cheng Hwang Process for the removal of impurities from gas streams

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
STEVEN F MEYER ET AL.: "Dynawave Wet Gas Scrubbing: A New Alternative for Claus Unit Tail Gas Clean-up", 11 August 2006, MECS INC., XP002459089 *

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101915714A (zh) * 2010-08-26 2010-12-15 河南电力试验研究院 一种判断不同石膏脱水性能的方法
CN103349901A (zh) * 2013-06-14 2013-10-16 中国恩菲工程技术有限公司 烟气处理方法及其设备
CN103349901B (zh) * 2013-06-14 2016-07-06 中国恩菲工程技术有限公司 烟气处理方法及其设备
US10315149B2 (en) 2014-01-07 2019-06-11 Mecs Inc Gas inlet system for wet gas scrubber
EP3175907A1 (fr) 2015-12-04 2017-06-07 Lab Sa Installation et procédé d'épuration des fumées d'échappement d'un moteur d'un navire marin
FR3044562A1 (fr) * 2015-12-04 2017-06-09 Lab Sa Installation et procede d'epuration des fumees d'echappement d'un moteur d'un navire marin
KR101911309B1 (ko) * 2017-05-15 2018-10-24 (주)엔코아네트웍스 폐 황산화물 가스를 이용한 황산나트륨 제조 장치
WO2018218152A1 (fr) * 2017-05-25 2018-11-29 Fisher Agc, Llc Procédés de capture de composés gazeux contenant du soufre à partir d'un gaz naturel contenant du sulfure d'hydrogène
US11224835B2 (en) 2017-05-25 2022-01-18 Fisher Agc, Llc Methods for the capture of gaseous sulfur-containing compounds from a natural gas containing hydrogen sulfide
CN107281924A (zh) * 2017-08-09 2017-10-24 安徽理工大学 一种改进的氨法脱硫工艺及系统
CN108176202A (zh) * 2017-12-26 2018-06-19 北京亘源环保有限公司 一种脱硫吸附剂的制备方法及应用
WO2020014015A1 (fr) 2018-07-11 2020-01-16 Mecs Inc Suppression de panache à l'aide d'échangeurs de chaleur à coque et tubes à thermosiphon
US11395987B2 (en) 2019-10-17 2022-07-26 Veolia North America Regeneration Services, Llc Scrubber system improvement for sulfur containing gas streams
CN114832610A (zh) * 2022-04-02 2022-08-02 徐州宏阳新材料科技股份有限公司 一种竖炉烟气的深度脱硫方法

Similar Documents

Publication Publication Date Title
WO2008100317A1 (fr) Épurateur pour la désulfuration de courants gazeux
CN106659971B (zh) 用于从排气中除去污染物的方法和装置
Roy et al. SO2 emission control and finding a way out to produce sulphuric acid from industrial SO2 emission
AU2004220725B2 (en) Improved process for the removal of contaminants from gas
US7052662B2 (en) NOx, Hg, and SO2 removal using alkali hydroxide
US5565180A (en) Method of treating gases
AU2010319665B2 (en) Process for removing contaminants from gas streams
EP1950176B1 (fr) Procédé pour l'élimination d'impuretés de flux gazeux
US5364604A (en) Solute gas-absorbing procedure
JP5000557B2 (ja) 湿式排煙脱硫装置
US20170029343A1 (en) Sulfur enhanced nitrogen production from emission scrubbing
US20020110511A1 (en) Horizontal scrubber system
KR101336874B1 (ko) 가스 내의 오염물의 흡수를 위한 시스템 및 방법
CA2629987A1 (fr) Procede de desulfurisation des gaz de combustion faisant appel au peroxyde d'hydrogene
CA2618778C (fr) Procede d'extraction de contaminants presents dans des flux gazeux
Kumar et al. Advances in absorbents and techniques used in wet and dry FGD: a critical review
RU2698835C2 (ru) Способ и устройство для частичного удаления загрязнений из технологического газового потока
KR100225473B1 (ko) 기류로부터 이산화황과 산화질소를 제거하기 위한 공정
Dehghani et al. FLUE GAS DESULFURIZATION METHODS TO CONSERVE THE ENVIRONMENT.
US20060198778A1 (en) Reduction of NOx in fluid catalytic cracking regenerator off-gas streams
JP3876290B2 (ja) 煙道ガス洗浄方法
Davenport et al. Sulphuric acid manufacture
Dzhonova-Atanasova et al. Current problems and development in flue gas desulfurization
CN109179339B (zh) 中低浓度酸性气的硫磺回收工艺
Matla et al. Factors Effecting Efficiency Prediction of Limestone-gypsum Wet Flue Gas Desulphurization Based on Oxidation Reaction

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 07757139

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 07757139

Country of ref document: EP

Kind code of ref document: A1