JPH03154611A - Gas cleaning method - Google Patents

Abstract

PURPOSE: To separate and remove a target component from a gaseous stream contg. >=1 components by bringing the gaseous stream into contact with a granulated liquid absorbent at a prescribed velocity, then flocculating the adsorbent and bringing the flocculation into contact with the gaseous stream of a prescribed concn. CONSTITUTION: Droplets which are the granulated liquid adsorbent sprayed from a spray head 14 advance in a direction where the droplets flow backward from the gaseous stream contg. the >=1 kinds of components while the forward motion is decelerated. The liquid adsorbent droplets advance from the gas rich in the one component to be removed at a point A to a region where the gas is scarce in the at least one component to be removed. The liquid adsorbent from the wall surface of a conduit 10 is discharged to a receiver 22 arranged below a demister 20. The receiver 22 collects the liquid adsorbent from both of the wall surface and the demister 20. A pipeline 24 removes the flocculated liquid adsorbent from the system.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for removing components from a gas stream by contacting with atomized droplets of a reversible sorbent for the components to be removed.

BACKGROUND OF THE INVENTION Various methods have been proposed for removing components from gas streams, including liquefaction, adsorption, absorption, momentum separation, and the like.

One common procedure is to contact a liquid sorbent to preferentially sorb the components to be separated. Sorption can be divided into physical sorption, where the component is soluble in the liquid sorbent, and chemical sorption, where a chemical reaction occurs with the sorbent. For example, sorption of sulfur dioxide into water Sorption is defined herein as physical sorption, and sorption in which sulfur dioxide forms calcium sulfite with calcium hydroxide is defined herein as chemisorption. Chemisorption is essentially irreversible 0 For example, the reaction of calcium hydroxide and sulfur dioxide to form calcium sulfite is essentially irreversible;
Alternatively, reversible methods include, for example, hydrogen sulfide sorption by alkanolamines. Conventionally reported gas-liquid contact mechanisms include dish towers, bag towers, spray towers, and the like.

Sorption methods have been proposed to remove widely varying components from widely varying gas streams, such as carbon dioxide and/or hydrogen sulfide and/or sulfur dioxide, from natural gas, air, Examples include removal from flue gas and petrochemical streams. Sorption methods can recover volatile catalyst from process streams. In many cases, the industrial feasibility of these sorption methods depends, in part, on the efficiency and capacity of the liquid sorbent, the ability of the liquid sorbent to be regenerated, and the energy consumption of the sorption method. For example, the sorption method should avoid undue pressure drops on the gas to be treated, especially large volumes of gas such as flue gas, and when regenerating the liquid sorbent. , it should be ensured that an unreasonable amount of energy is not wasted.

One type of device that does not cause undue pressure drops is known as a "Waterloo" scrubber and is
“Mist and Dust Manipulation J” by Chem-tec
h, June 1988, pages 364-368). U.S. Pat. No. 4,067,703 discloses a Waterloo scrubber for particle removal. According to the above article, US Patent Application No. 2 related to the use of the Waterloo Scrubber as a chemical reactor.
No. 0963 has been submitted.

The Waterloo scrubber consists of a duct through which the gas to be scrubbed flows and an atomizing nozzle to spray liquid into the passing gas stream. sent to. In this zone, the liquid condenses into large droplets that can be easily separated from the system. An entrainment separation zone can also be provided after the turbulent mixing zone to further recover the liquid.

Because a large portion of the liquid is removed in the turbulent mixing zone, the pressure drop created by the entrainment separation zone is much smaller than if substantially all of the liquid had to be removed in the entrainment separation zone. In the above article, Spink states that ``Waterloo SO scrubbers produce much lower LG (Liqui
d-to-Gas) ratio
can be removed J (stated as 366 basis).

Spink reports the use of ammonia, Mg0-containing lime, sulfite rum liquor and iron oxide slurry as sulfur dioxide removal agents.

Therefore, sorption methods are being sought that effectively utilize the capabilities of liquid sorbents, yet still obtain the benefits of low pressure drop scrubbers such as spray towers and Waterloo scrubbers.

SUMMARY OF THE INVENTION The present invention provides a sorption method for removing components from a gas stream with a small pressure drop and effective use of a liquid sorbent. a liquid sorbent in the form of atomized droplets and a gas outlet containing at least one component capable of being reversibly sorbed by the liquid sorbent; The droplet is assumed to have velocity components parallel and perpendicular to the direction of gas flow. The contact of the droplets is such that some of the droplets have a concentration of at least one component that is greater than the projected vapor-liquid equilibrium concentration under the conditions of the gas at the gas outlet. During a period of time sufficient for at least one component to be sorbed, the droplet has a concentration of at least one component that is a number greater than the calculated gas-liquid equilibrium concentration under the conditions of the gas at the gas outlet. A portion of the droplets aggregates in the contact zone, and then these aggregated droplets have a vapor-liquid equilibrium concentration of the at least one component that is lower than the concentration of the at least one component in the droplet. The gases that have gases are removed from the contact zone before they equilibrate with said gases.

In a preferred aspect of the invention, at least 30% by volume
A droplet of liquid is coagulated under the pressure inside the contact zone, and the specific liquid of the coagulated liquid is
on average at least about 1 greater than that calculated at vapor-liquid equilibrium under the conditions of the gas upon exit from the contacting zone.
In another aspect of the invention, the droplets contain at least one physical sorbent for at least one component and at least one component at a large concentration of at least one component. at least one chemical sorbent for the species components, wherein the chemical sorbent is soluble in the physical sorbent. Advantageously, at least one of the components is sorbed by a physical sorbent prior to chemisorption.

In another preferred aspect of the invention, a gas stream containing sulfur dioxide is contacted with an absorption medium in the form of atomized liquid droplets. The absorbent medium comprises (i) water and (II) about 4.5-7.3, preferably 4.5-6.3 in free form.
pKa of 7 (measured in aqueous medium at 25°C)
* pKa is the negative logarithm of the ionization constant of the conjugate acid of the base. This amine group is herein referred to as the "sorption capacity XJ." The atomized liquid sorbent provides points of larger surface area available for gas-liquid contact between a given volume of gas and the liquid sorbent. Advantages are obtained in the lower pressure drop provided by the droplets, which are often less than about 200 microns in diameter, and to the gas passing through the contacting zone.
For example, between about 5 and 80 microns, and in some cases between 20 and 100 microns.

The droplets can be applied to a spray nozzle, a gas-assisted spray nozzle,
It can be formed by any suitable atomization or spray device including, but not limited to, a Subini/Guzisk atomizer and the like. Often these devices produce a distribution of droplet sizes; usually the particle size distribution is such that at least about 50% by volume of the droplets are within an average droplet size of 20 microns.

Unlike conventional countercurrent spray towers, which use droplets large enough to avoid undue entrainment in the upwardly flowing gas, the atomized droplets used in the process of the present invention are easily fluidized. , or even by a relatively low velocity gas. In the method of the present invention, the velocity of the gas in contact with the atomized droplets is preferably greater than or equal to the critical sedimentation velocity, or greater than or equal to the critical flow velocity. , critical settling velocity or critical flow velocity is the gas velocity at which droplets of average particle size are suspended in a countercurrent vertical vessel with the same cross-sectional shape and dimensions of the contacting zone. Of course, the critical flow velocity varies with the cross-sectional shape and dimensions of the contacting zone, the droplet size, and the droplet density.

Often, the average linear velocity of the gas containing the at least one component to be removed is at least about 1.5 meters per second, such as about 1.5 meters per second or 3 meters to 15 meters or more; And the flow is non-laminar.

The contacting zone can have any suitable cross-sectional shape provided that the droplets of liquid sorbent are sufficiently distributed over the cross-section to effect the desired sorption. The cross sections are circular, oval, square, rectangular, hexagonal, and 8
It can be rectangular, etc. Often the aspect ratio (largest dimension to smallest dimension) of the cross-sectional shape of the contact zone is approximately 3=1.
and 1°C, preferably between 1.5:1 and 1°C.

The cross-sectional area is also selected, in part, based on the ability to distribute appropriate droplets of liquid sorbent across the cross-section. Another consideration is the ability of the atomized droplets to coalesce into large liquid bodies, as explained in detail below. The walls of the contact zone can serve to promote agglomeration and therefore have a cross-sectional area that typically allows a significant portion of the droplets to readily contact the walls upon sorption of the desired amount of at least one component. The cross-sectional area is as follows. The cross-sectional area of the contact zone often ranges from about 100 to 15 or more, so to speak, from about 0.02 to 1 ol K''.

The contact zone can be oriented in any suitable direction. The band is either reverse fL (uP −f10w) gas or forward flow (d
own-f10w) can be vertical or non-vertical with gas. Preferably the zone is substantially horizontal, ie within about 15 degrees, so to speak, within about 10 degrees of the horizontal. In many cases, a substantially horizontal orientation takes advantage of the effects of gravity on the droplet and facilitates the droplet contacting the lower wall of the contact zone.

Micronized droplets of liquid sorbent can be provided by any suitable means in the cross section of the contact zone. - atomized droplets of liquid sorbent are introduced into the membrane from the center of the cross section in the form of a fan spray or a cone spray, the spray being directed into the gas stream containing at least 18 i of the component to be removed; On the other hand, the flow is countercurrent or cocurrent. Therefore, the atomized droplet has a radial velocity component. (Here, the direction of gas flow is defined as being axial). Often the spray form is Fi5-9
0 degrees, so to speak, encompasses angles between 10 and 40 degrees. The angle of the spray form, in particular the angle of the outer portion of the spray form, determines the contact time of the droplets with the gas before they contact the walls of the contact zone. Advantageously, the atomized droplets of liquid sorbent used in the method of the invention increase the approximate rate of sorption due to the high surface area per unit volume of sorbent. Therefore, even during the relatively short residence time of the atomized droplet between its generation and contact with a surface, a substantial amount of at least one component is sorbed. can be done.

- For countercurrent spraying, which is preferred in the membrane, the axial velocity of the atomized droplets is reduced by the gas, eg reversing the axial velocity of the droplets unless they touch a surface.

For co-current spraying, the droplets are entrained in the gas flow and tend to have an axial velocity that is the same as the axial velocity of the gas in the film. In many cases, regardless of which of the above spray forms is used, a substantial portion of the droplets will be in contact with the gas enriched in the at least one component to be removed;
It is then contacted with a gas having a lower concentration of the at least one component to be removed.

Since the liquid sorbent is a reversible sorbent, the concentration of at least one component in the liquid sorbent and in the gas tends toward equilibrium, ie, gas-liquid equilibrium. At equilibrium, the at least la! to be removed! The concentrations of the components of in the liquid sorbent and in the gas are determined by the vapor-liquid equilibrium curve for the system.

According to the method of the invention, the atomized droplets of liquid sorbent are contacted with a gas enriched in at least 111 [components to be removed, and then the at least one component to be removed is come into contact with a gas that has a concentration. Some of the atomized droplets of liquid sorbent in contact with the rich gas coalesce to form large bodies (eg, droplets or films) of liquid sorbent with a low area-to-volume ratio. This low area to volume ratio slows down the rate of sorption and the approximate rate of desorption from the liquid body. Advantageously, the agglomerated liquid, if in the form of droplets, has an average diameter that is at least about 5 times, so to say 10 to 50 times or more, larger than the average diameter of the atomized droplets.

Preferably, at least a portion of the agglomerated droplets form a continuous film or stream that progresses from the contacting zone to the outlet.

Agglomeration of the droplets can be by any suitable means. If pressure drop considerations are important, any means of promoting flocculation should present minimal resistance to gas flow. Conveniently, the walls of the contact zone are used as at least part of the means for agglomerating the atomized droplets. The use of walls minimizes any pressure drop to the gas. Other means of increasing cohesion include providing contact surfaces within the cross-section of the contact zone. - A solid surface within the membrane is preferred, since liquids may tend to dilute the liquid sorbent and make recovery and/or regeneration more difficult.

Frequently, at least 30% by volume of the liquid sorbent aggregates before reaching the outlet of the contact zone. Preferably, a significant portion of the atomized droplets is such that the concentration of at least one component in the liquid sorbent is calculated under conditions of the gas as it exits the contacting zone. ft (pr
The vapor-liquid equilibrium concentration is the concentration of at least one component in the liquid sorbent that is in equilibrium with the concentration of at least one component in the gas. The temperature and pressure of the gas as it exits the contact zone is used to confirm the vapor-liquid equilibrium relationship. The outlet of the contacting zone removes substantially all of the remaining non-agglomerated liquid sorbent from the gas or
or where the gas still contains liquid sorbent, where it is subjected to another unit operation, such as another sorption step, chemical reaction, heat exchange, etc.

In one example, if the atomized droplet has a concentration of at least one component that is at least about 1 ON greater than the calculated vapor-liquid equilibrium concentration under the conditions at the exit of the contacting zone, then the atomized droplet At least about 30% of the droplets aggregate.

In a preferred aspect of the invention, the liquid sorbent comprises both a physical sorbent and a chemical sorbent for the at least one component to be removed.

Without wishing to be bound by theory, it is believed that the use of two sorbents enhances the ability of the liquid sorbent to recover at least one component from the gas. Sorption occurs by first sorbing at least one component into a physical solvent. The at least one component in the physical solvent tends to equilibrate with the at least one component bound to the chemical sorbent. Therefore, if some of the at least one component is desorbed into the ambient gas due to equilibrium requirements, the equilibrium concentration of at least one component bound to the chemical sorbent changes and the reaction proceeds. Some of the components of one species are desorbed from the chemical sorbent; therefore, adding chemisorption to the physical sorption step provides additional time for flocculation to occur. On the one hand, the droplets can have a concentration of at least one component that is greater than or equal to the calculated vapor-liquid equilibrium concentration under the conditions at the outlet of the contacting zone.

Not all of the liquid sorbent is aggregated in the contacting zone; aggregation means are generally provided at the outlet from the contacting zone to remove substantially all residual entrained liquid sorbent from the gas. A suitable agglomeration means is a Demister-1 centrifugal blower,
Includes chevron, etc. The residence time of an atomized droplet in the contact zone varies depending on the axial and radial velocity components of the droplet and the length of travel within the contact zone. Generally, the average contact time is about 2 seconds or less, such as about 0.001 to 1 second, so to speak, about 0.01 seconds.
to 0.5 seconds. Typically some atomized droplets have a much shorter average residence time than other atomized droplets, such as about 60% or less, and others about 150%. or longer residence time.

The ratio of liquid to gas containing at least one component is large (and can vary; factors considered are the amount of the at least one component to be removed, the number of at least one component in the gas to be treated). These include the concentration of the components of the pole, the capacity of the liquid sorbent for the at least one component to be removed, the sorption rate, and the shape of the contacting zone, including the cross-sectional dimensions.

Often the ratio of liquid sorbent to gas is about 0.001 to 5 liters per cubic meter, such as about 0.01 to 1 liter.

Wide range of gases t/1. The method of the present invention can be used for ft processing to remove a wide range of components. Virtually any liquid sorbent method using a reversible sorbent can be used in the method of the present invention. Typical gas streams for processing are natural gas streams (e.g. to remove carbon dioxide or hydrogen sulfide), petrochemical gases (e.g. vaporized catalysts, - carbon oxides, carbon dioxide, polar organics, non-polar organics, (to remove hydrogen sulfide, sulfur dioxide, nitrogen oxides, etc.), combustion gas R, (e.g. to remove nitrogen oxides, carbon dioxide, sulfur dioxide, etc.), and air (e.g., halogenated hydrocarbons such as trichloroethylene; solvents including oxygenated solvents such as acetone, ketones, glycol ethers, etc.; nitrogen oxides; carbon oxides; carbon dioxide; hydrogen sulfide; mercaptans; and methods for removing sulfur dioxide). , the physical solvent is water,
Hydrocarbons (% pentane, hexane, cyclopentane,
cyclohexane/, pen'zene, toluene and hyxile/)
, ethers (e.g. diethyl ether, cryptand,
polyethylene glycol, glyme, tetraglyme, etc.), alcohol (e.g. methanol 1, ethanol,
gropanol, ingropanol, t-phthanol, ethylene glycol and diethylene glycol), and nitrogen compounds (eg, aniline, pyridine, pyrimidine, pyrrolidone, etc.). Chemical sorbents include amines, alkanolamines such as jetanolamine and triethanolamine, alkyl alkanolamines such as methyl jetanol, weak carboxylic acids, Fe%
transition metal ions such as Mo, Cu, Ag, Cr, and CO; aldehydes such as benzaldehyde;
Includes carbonates such as potassium carbonate, halogenated hydrocarbons, urea, and the like. Advantageously, the chemical sorbent is insensitive to Henry's law, ie, the concentration of the at least one component to be removed in the gas and the concentration of the component in the liquid sorbent are The vapor-liquid equilibrium relationship between the concentration of at least one component to be removed is non-linear.For 1M, the vapor-liquid equilibrium curve is at least partially below the linear relationship to He/Lee's law. be.

A particularly preferred application of the process of the invention is the removal of sulfur dioxide from combustion processes and smelter effluent gases.

Preferably used amine sorbents have at least one amine group (sorbed nitrogen) exhibiting a pKa value between approximately 4.5 and 6.7. Because pKa values of amines change with temperature, all pKa measurements were performed at 25° C. in aqueous media for uniformity.

Amine sorbents may be monoamines or may have two or more amines. In a preferred embodiment, the amine has a salt group that is substantially non-renewable under sorption and regeneration conditions.

Salts tend to reduce the vapor pressure of the amine sorbent.

Most conveniently the salt function is provided by at least one other amine group on the amine sorbent.

Generally, in the sorbent medium, the amine salt absorbent constitutes at least about 50 mole percent, preferably at least 70 mole percent, such as 75 mole percent to substantially 100 mole percent, of the total amines capable of absorbing sulfur dioxide.

Diamines are preferred as amine salt absorbers because of their availability and low molecular weight. Diamines are often used because of their commercial availability and generally low viscosity and have a
00 or less, preferably about 250 or less.

Amines, such as diamines, are preferably tertiary amines from the standpoint of their stability. However, if mild oxidizing or thermal conditions exist to minimize solvent chemical reactions, then one or both nitrogens may be primary or secondary, and the critical parameters discussed below Other amines that satisfy the aspect can be used. Often preferred amine salt absorbers have a hydroxyalkyl group as a substituent on the amine group. Preferred compounds for 0% are N, N' where the hydroxy substituent appears to retard the oxidation of sulfite or bisulfite to sulfate.

N'-()dimethyl)-N-(2-hydroxyethyl)
-Ethylenediami7 (pKa = 5.7); N
, Ns N'+ N'-tetramethylethylenediamine (pKa=6.1); N, N, N', N'-tetrakis(2-hydroxyethyl)ethylenediamine (
pm=4.9); N-(2-hydroxyethyl)ethylene di7my (pKa=6J); N, N'-
Dimethylbiherazine (pKa=4.8); Ne
Ns N'* N'-tetrakis(2-hydroxyethyl)-1,a-diaminopropane; and N',
N'-dimethyl-N,N-bis(2-hydroxyethyl)ethylenecyamine. Also included among the useful diamines are piperazine (pKa = 5.8)
It is a heterocyclic compound such as. pKa values are for sorbed nitrogen.

The absorption medium contains at least one mole, and usually more, of water for each mole of sulfur dioxide to be removed from the gas stream. Water acts both as a solvent for the amine and as an absorbent for the sulfur dioxide. The proportion of water present is about 80% by weight of the absorption medium, preferably about 25 to about 50% by weight of the absorption medium.

It is not a requirement that the amine sorbent and water be miscible under any conditions of the process, nor is it a requirement that the amine sorbent be liquid under all conditions of the process. , often the solubility of the amine sorbent in water is at least about 0.01 per liter of water at 25°C.
mole, often about 0.1 mole. Preferably the amine sorbent is miscible with water under the conditions of the process.

The amine sorbent (calculated as free amine) often accounts for at least about 20% by weight of the absorption medium, e.g.
It constitutes 90'M weight %, so to speak, about 25 to 75 weight X.

The amount of amine sorbent is preferably sufficient to provide a waste absorption medium containing at least about 10 of sulfur dioxide per block of absorption medium. However, the amount of amine sorbent should not be so large that it unduly increases the viscosity of the absorption medium and prevents adequate spray droplet size from being obtained, preferably the viscosity of the absorption medium is about 1200 at 25°C. less than centipoise, e.g. about 1 at 25°C
centipoise and about 50 θ centipoise.

The absorption medium may contain a mixture of amine sorbents, such as alkaline salts to retard the oxidation of sulfite or bisulfite, to act as pH-maintaining companions and co-solvents, etc. compounds can be present as additives.

The contacting of the absorption medium with the sulfur dioxide-containing gas stream should be carried out at a temperature up to about 60°C, often from about 10 to about 60°C, preferably from about 10 to about 50°C, and at least sulfur dioxide per kf of absorption medium. 101° preferably about 200~
5 to obtain a sulfur dioxide loading of 4002.

Without wishing to be bound by theory, it is believed that bisulfite ions are produced when sulfur dichloride is dissolved in water. The bisulfite ion then ionically associates with the sorbed nitrogen of the amine sorbent.

For high sulfur dioxide removal and energy efficient regeneration, the pH of the absorption medium should be maintained such that the bisulfite/sulfite equilibrium in the carcass absorption medium is biased toward bisulfite. To a significant extent, amine sorbents having a pKa in the range of about 4.5 to 7.30 tend to buffer the waste absorption media to a pH in the range of about 4 to 6, favoring the presence of bisulfite. be.

The pH of the absorption medium generally ranges from about 4 to about 7.5 during the absorption process; typically the absorption medium has a pH near the upper end of this range, preferably from about 6.5 to about 7.5. pH
The pH moves towards the lower end of the range as sulfur dioxide is absorbed and the solution becomes more acidic.

If the absorption medium has a high pH, sulfur dioxide is absorbed as sulfite ions, thereby making stripping of a significant proportion of the absorbed sulfur dioxide difficult to achieve.

If the pH is too low, will oxidation occur from the dilute sulfur dioxide gas stream normally encountered under normal atmospheric pressure conditions? The yellow color is too small to be absorbed.

1 schematically shows a contacting zone operable according to the method of the invention, suitable for receiving an inflow gas passing in the direction of the arrow, containing at least one component to be removed; FIG. A conduit 10 is provided having an inlet.

The pipe 12 is adapted to transport liquid sorbent to a spray head 14 oriented to spray a conical form 16 of atomized liquid sorbent countercurrently to the gas flow. The dotted line 18 shown in FIG.
Eventually, the particles reverse their axial motion and move in the direction of the gas flow. The path also shows the effect of gravity on this droplet. As shown, the droplet is at point A at least 1. Demister 20 for agglomerating the residual droplets entrained in the gas downstream of the spray nozzle 14, where the gas passes from the gas rich in the at least one component to be removed to the region deficient in the at least one component to be removed. There is.

Liquid sorbent from the wall of the conduit 10 is discharged into a receiver 22 located below the demister 20.

Receiver 22 collects liquid sorbent from both the wall and the demister. Conduit 24 is adapted to remove aggregated liquid sorbent from the system.

In FIG. 2, the same parts as in FIG. 1 are given the same reference numerals as in FIG. In FIG. 2, the spray is cocurrent with the gas flow. Droplet paths 26 and 28 are shown to illustrate the effect of gravity on the droplets.

The following examples are provided by way of further illustration of the invention and are not intended to limit the invention; all parts and percentages of solids are by weight unless otherwise stated. Yes, and parts and percentages of liquid are by volume.

Example 1 Synthetic regenerated absorption medium was prepared from N,N',N'-trimethyl-N
-(2-Hydroxyethyl)ethylenediamine 360 bond (i641#), 98X sulfuric acid 123 bond (56k
p) and steam condensate 1080 Bond (491 kf).

This mixture exhibits a pH value of approximately 7.76.

The above mixture is sprayed into a duct through which a synthetic sulfur dioxide-containing stream is passing. This duct is approximately 12 inches (30,5α) in diameter and has a diameter of approximately 50 bonds/in”
It houses three atomizing nozzles in parallel (nozzle 1 closest to the outlet of the duct) using atomizing air at (gauge pressure) (3.4 atmospheres).

If more than one nozzle is used, the lean solvent is passed through nozzle 1, then the recovered solvent from nozzle l (full vent) is passed through nozzle 2, then through nozzle 2.
to nozzle 3 (if used) to achieve maximum loading of solvent. The atomized droplets have a diameter of approximately 20
It is believed to be between 35 and 35 microns. At the exit end of the duct is a radial blower approximately 30 inches (76 m) in size. Collect waste solvent from the blower casing and downstream removal equipment. Sulfur dioxide at 22°C and relative humidity 40°C
Mix in the air eaves of 96 and pass this flow through the duct 6
Table I summarizes the test experiments, conditions and results. A defrost system [is present after each of nozzle 3 and nozzle 2, and the solvent SO2 loading mentioned in Table I is
Based on the liquid recovered from the device.

Example 2 - In these examples, a $1 Kimre™ Mist Eliminator deploys a circular cross-section conduit having an internal diameter of about 29.2 cm at an incline of about 2 degrees with the inlet end rising above the horizontal plane. -Model 16/96 (Kimre Incorporated, Bellin, Florida, USA)
(obtained from ) at the other end of the conduit. CALDYN
(Trademark) Air Assisted Spray Nozzle C2mtft) (Ca1d71 Apparatebn, Ettlingen, West Germany)
GmbH) is positioned axially within the conduit;
A liquid sorption line and an air line are passed through the nozzle.

In these examples, air is mixed with a metered amount of sulfur dioxide and passed through a conduit at 17° C. at approximately ambient pressure; the air to the nozzle is approximately 60 pounds/in.
and sprayed with a liquid sorption solution containing a synthesis medium as described in Example 1 and as follows. The liquid is metered using a helical gear pump and is at a temperature of approximately 17°C.

The spray cones are about 12-15, the average droplet size is about 50 microns, and the droplet distribution is about 20-15.
00 microns range.

In the counter-current embodiments (Examples 1.2.3.4 and 6), the face of the nozzle is approximately 7-8 cm from the mis-eliminator turn and the water column of the spray is at the nozzle. It has spread to about 85 to 90 countries.

In the co-current embodiment (Example 5), the face of the nozzle is approximately 130-135 a* from the mist eliminator, and the water column of the spray extends to the mist eliminator. The sulfur dioxide concentration in the absorption medium is determined by pH measurements, and the sulfur dioxide in the air is determined by on-line infrared spectroscopy.

These examples are summarized in Amai ■.

In each of these examples, about 40 to
50% contacts and fuses to the wall of the conduit.

[Brief explanation of the drawing]

FIG. 1 is a cylindrical diagram of the apparatus for countercurrent liquid sorption spray used in the method of the present invention, and FIG. 2 is a simplified diagram of the apparatus for cocurrent flow. Approximately 1 Juice Applicant Union, Carnoquid, Canada,
Amendment of engraving procedure for limited drawings F/G. 72/77/2017

Claims (1)

Claims: 1. A gas stream containing at least one component, capable of reversibly sorbing the at least one component and in the form of atomized droplets; contacting with a liquid sorbent, where the velocity of the gas flow is greater than or equal to the critical sedimentation velocity of the droplets in the contact zone, and the contact is for a sufficient time to sorb a portion of the at least one component. Let a portion of the droplets aggregate in the contacting zone, where the droplets have a concentration greater than the concentration calculated (released) in vapor-liquid equilibrium under the conditions of the gas flow upon exiting the contacting zone. said agglomerated droplets having a concentration of at least one component, said agglomerated droplets being contacted with a gas stream, said gas stream having a concentration calculated (released) in vapor-liquid equilibrium under conditions of said agglomerated droplets; and then removing the agglomerated droplets from the contacting zone before the at least one component in the agglomerated droplets equilibrates with the gas flow; A method for separating at least one component contained therein from a gas stream. 2. At least about 30% by volume of the droplets are agglomerated in the contacting zone; and the agglomerated droplets are calculated relative to the gas-liquid equilibrium of the gas stream under the conditions under which the gas stream exits the contacting zone. on average at least about 10
2. The method of claim 1, having a concentration of said at least one component that is mol % greater. 3. The method of claim 2, wherein about 30-70% by volume of the droplets coalesce within the contact zone. 4. The method of claim 3, wherein at least a portion of the droplets are agglomerated by contacting a surface within the contact zone. 5. the droplet has an axial velocity component and a radial velocity component;
5. The method of claim 4, wherein a portion of the droplet contacts an internal surface of the contacting zone prior to exiting the contacting zone. 6. The method of claim 1, wherein the atomized droplets are initially ejected countercurrently to the direction of flow of the gas stream. 7. The method of claim 1, wherein the atomized droplets are first ejected co-currently with respect to the direction of flow of the gas stream. 8. The liquid sorbent includes a sorbent having a nonlinear vapor-liquid equilibrium relationship with respect to at least one component, and the vapor-liquid equilibrium relationship is less than or equal to that predicted by Henry's law. 2. The method of claim 1. 9. Claim 8, wherein the liquid sorbent comprises at least one physical sorbent for at least one component and at least one chemical sorbent for said at least one component.
Method described. 10. The method of claim 1, wherein the liquid sorbent comprises at least one physical sorbent for the at least one component and at least one chemical sorbent for the at least one component. 11. The method of claim 1, wherein the droplets have an average diameter of about 5 to 100 microns. 12. The method of claim 1, wherein the linear velocity of the gas flow in the contacting zone is about 3 to 15 meters per second. 13. The method of claim 1, wherein the contact zone is substantially horizontal. 14. The method of claim 1, wherein at least about 30% by volume of the droplets exit the contacting zone with the gas flow. 15. A method of separating at least one component contained therein from a gas stream, the gas stream containing the at least one component having an average diameter between about 5 microns and about 100 microns. is contacted with a liquid sorbent in the form of atomized droplets having a The sorbent includes at least one physical sorbent on which the at least one component can be reversibly sorbed and at least one physical sorbent on which the at least one component can be reversibly sorbed. of a chemical sorbent, and in this case the velocity of the gas stream is about 1.5 to 15 meters per second, and the contact is calculated at vapor-liquid equilibrium under the conditions of the gas stream at the outlet of the contacting zone ( (emitted) for a sufficient period of time to provide droplets containing at least about 10 mole percent more of the at least one component than the concentration released; about 30 volume percent and 70 volume percent in the contact zone; agglomerating droplets between the contact zone, wherein the droplets contain a concentration of the at least one component greater than the concentration calculated (released) in vapor-liquid equilibrium under the conditions of gas flow at the outlet of the contacting zone. said agglomerated droplets and a gas stream having a concentration of said at least one component less than or equal to the concentration calculated (released) in vapor-liquid equilibrium under the conditions of said agglomerated droplets; contacting; and then removing the agglomerated droplets from the contacting zone before the at least one component in the agglomerated droplets equilibrates with the gas flow. 16. The method of claim 15, wherein the droplets are agglomerated by contacting at least a portion of the droplets with the inner surface of the contact zone. 17. The method of claim 16, wherein the droplet has axial and radial velocity components, and wherein a portion of the droplet is brought into contact with the inner surface of the contacting zone prior to exiting the contacting zone. 18. The method of claim 17, wherein the atomized droplets are first ejected countercurrently to the flow direction of the gas stream. 19. The method of claim 17, wherein the atomized droplets are first ejected co-currently in the flow direction of the gas stream. 20. Claim 20, wherein the liquid sorbent includes a sorbent having a nonlinear vapor-liquid equilibrium relationship with respect to at least one component, and the vapor-liquid equilibrium relationship is less than or equal to that predicted by Henry's law. 17. The method described in 17. 21. A method for removing sulfur dioxide from a sulfur dioxide-containing gas stream, comprising: (i) at least about 1 mole for each mole of sulfur to be absorbed; water in an amount up to about 80% by weight of the absorption medium, and (ii) p in the aqueous medium at 25°C of about 4.5 to 6.7 at temperatures up to about 60°C when in free form.
an amine sorbent having at least one amine group that is a group having a Ka;
wherein the velocity of the gas stream is at least about 1.5 meters per second, and the contact is such that some of the atomized droplets sorb sulfur dioxide as the gas stream exits the contact zone. for a period of time sufficient to provide a concentration of sulfur dioxide in a portion of the liquid droplet that is greater than the vapor-liquid equilibrium concentration calculated (released) under the conditions of the gas stream at; aggregating in the contacting zone a portion of the droplets having a concentration of sulfur dioxide greater than the vapor equilibrium concentration calculated (released) under the conditions of the gas flow as it exits the contacting zone; contacting the droplets with a gas stream having a concentration of sulfur dioxide less than or equal to the vapor-liquid equilibrium concentration calculated (released) under the conditions of the agglomerated droplets; then the sulfur dioxide in the agglomerated droplets is removing the agglomerated droplets from the contacting zone prior to equilibration with the flow. 22. The method of claim 21, wherein the amine sorbent contains a salt group that is stable upon contact. 23. The method of claim 21, wherein the amine group of the amine sorbent comprises a secondary amine or a tertiary amine. 24. The method of claim 23, wherein at least one amine group of the amine absorbent has at least one hydroxyalkyl substituent. 22. The method of claim 21, wherein the method is selected from the group consisting of (2-hydroxyethyl)-ethylenediamine and N,N,N',N'-tetramethylethylenediamine. 26. The method according to claim 21, wherein the diamine is piperazine.