CS214669B2 - Method of removing the soiling agents from the gases - Google Patents

Description

(54) Method of removing pollutants from gases

The present invention relates to a process for wetly removing specific components from gases containing such contaminants. In particular, the invention relates to a process for wetly removing specific components, such as certain gaseous components or certain solid components, from a gas containing said contaminants, using a scrubbing column comprising at least one Morethane tray. .

As used herein, the term " Morethane tray " refers to a perforated tray or grate tray without an overflow and downcomer.

As is known in the art, known methods for wetly removing specific components from gases containing these contaminants include, for example, processes where the gas is treated in countercurrent contact with the scrubbing liquid in a conventional column. with perforated trays having a free area ratio (F _C J of less than 0.30, in a packed column, in a spray scrubbing column, in a bubbling cap tray column, and the like.

With respect to these prior art processes, it is noted that processes using packed columns have the following disadvantages: the formation of channels (so-called channel 2114669) of liquid and gaseous streams in the packed column and clogging or blocking of the packed column during the process in cases where the gas or liquid comprises solids, dust particles and the like. Processes using spray scrubbing columns have the following disadvantages: a large amount of energy is required to spray the liquid, and also entails entrainment of the liquid into the gaseous stream and thus an insufficient absorption capacity.

Processes that use tray columns, such as bubble-capped column trays, conventional perforated tray columns, and the like, also have some disadvantages, particularly with respect to column pressure drop which is relatively high, and the efficiency of these tray trays. Columns are usually low. In addition, the surface gas velocity in these tray columns is generally limited to a velocity ranging from about 0.3 m / s to about 2 m / s in conventional scrubbing columns. Due to this limitation, large column sizes have to be used when processing large flow rates of gas. It is clear from the above that it is necessary to propose and develop wet scrubbing processes with a higher absorption capacity than was the case. in prior art processes.

In an effort to overcome the above drawbacks and difficulties associated with conventional gas scrubbing processes, two of the three inventors of the present invention have proposed a process for removing specific components in the gaseous state and / or in the form of fine dust from contaminated gases. a gaseous component and / or a finely divided dust component, with an upstairs column comprising at least one perforated or slatted tray without overflow and downpipes, the tray having a free area ratio (F _c ) ranging from 0.25 to 0.25 0.60, at the surface velocity of the gas falling within the undulation region, and at the same time the liquid absorbent is passed down the column through said column trays in countercurrent. flow with respect to the upward movement of the gas through said column, wherein the liquid to gas ratio [L / G] is 0.5 or higher. This procedure is disclosed in Japanese Patent Application Publication No. 51-31036 (published September 4, 1976) and also in United Kingdom Patent No. 1,390,163 (published April 9, 1975). The aforementioned term undulation region is also defined in these publications. The following six equations are reported in these publications to determine the Ugm (i.e., the minimum surface velocity of the gas in the undulation range) and the Ugc (the maximum surface velocity of the gas in the undulation range) at a liquid flow rate ranging from 9000 to 110 000 kg / m ² . h. Four of these six equations are as follows:

- * == Fc = 49.14 ° - ³⁰ [X ΙΌ ^{3] '0} · ⁵ [

FcVgi Pi (2) ^Usl! ^ 40 ^ 92 = Fc ^{-0 '30} [X IO ^{3] 1 535} · [

FcVgi Pi (2) = 67.8 χ 10 ³ °

FcVgI ^G Pi _{= 76i} 7 [_L _] - ° .23 ₍ _Pm_ _{χ 10} 3] FeVgI G Pl (3)

1,255 (4) in which g is the gravitational acceleration in m / s ² , .F _{c the} ratio of the free area on the perforated or slatted floor (-),

L liquid flow rate in kg / m ² s, G gas flow rate in kg / m ² s, p _t liquid density in kg / m ³ , p _g gas density in kg / m ³

which is the capillary constant (m), and the surface tension in kg / s ² .

The above equation (1) is applicable to the perforated floor in cases where F _c 0,1 0.16 and ρ _β / ρι X 10 ³ 0,8 0.838, and equation (2) is applicable to the perforated floor in cases where F _c 0 0 , 16 ap _g / p _t XX 10 ³ 0,838, said equations (3) and (4) being applicable to the perforated tray (for F _c s values of 0,16) and to the grate tray in cases where p _g / p] X 10 ³ si ^ iS ^ resp. p _g / pi X 10 ³ <1.20. Í9semo olurn

Y? Íí9V inňvoo ojí lišrjoq nn 9í orí9fI9h9V [J

The remaining two equations are as follows:

_T , ^r - = 7.509 X ΙΟ ² XL · - ⁰ · ⁵⁷⁰⁴

U _gm

- = 3.444 X L 0 - ⁰⁸⁰⁷

Ugm

(6) in which L has the same meaning as in Equations (T) to (4).

The above equations (5) and (6) are applicable to perforated or slatted floors in cases where L values are in the range of L = 6 X 10 ⁴ up to 11 X 10 ⁴ kg / iri ² h, respectively. from L = 10 ⁴ up to L = 6 X 10 ⁴ kg / m ² h.

The aforementioned drawbacks and problems encountered in conventional wet scrubbing processes for gaseous contaminated compositions can be overcome to some extent by contacting the gas with the scrubbing liquid under conditions such as

-Iq io _n ,.

-oh: yboriyv9ti. -ojUububují ji.vx j)) n-.

# Τ4β'6 9

When the surface velocity of the gas is in the range of 9000 to 110 000 kg / m ² h when the process is carried out as described above (hereinafter referred to as the "prior art process"). However, at this point it should be noted that this prior art process is still practically unusable for industrial processes.

In view of the foregoing, it is an object of the present invention to overcome and overcome the above-mentioned drawbacks and problems of conventional techniques and to propose a process capable of removing specific gaseous and / or solid constituents contained in a polluted gas with high efficiency, wherein this process would allow gas scrubbing to be carried out at very high gas flow rates and at high liquid flow rates ranging from 10,000 kg / m ² to 250,000 kg / m ² h.

Other features and advantages of the present invention will become apparent from the following description.

(AND)

Ug _min = 1.60 X ΙΟ ² XL ^-0 ' ⁰⁸⁰⁷ XF _c °' ⁷ _1_

XX 103] -0> 5 χ _t __ L_ J 3

Pl b

According to the present invention, the process of removing specific components from a gas stream containing these pollutants comprises passing the gas through a scrubbing column from the bottom upwards, the scrubbing column having at least one perforated or grate tray without overflow and downpipes, and the trays or the tray has an open area ratio (Fc) ranging from 0.30 to 0.60, and said gas is passed through the scrubbing column at a surface speed in the range of from Ug _min to 8 m / s, scrubbing column scrubbing acid from bottom to bottom at a flow rate of liquid (L) ranging from 10,000 to 250,000 kg / m ² h, with a liquid to gas ratio [L / Gj of at least 0.5 and Ugmin being defined by the following relation:

(1) - perforated floor in the case where the value of L is between L = 10 UI and ^r L = 60 000 kg / m ² h:

x Vgi (7) (in which X 10 ^{3 to} 0.84)

Fri (II)

Ugmin = 1.41 X 10 ² X L- ⁰⁸⁰⁷ XF _c ° ⁷ _ 1

X ['-S- X 103] χ [__L_ J' 3 χ pi b

Vgi ( ^: 8) (in which X 10 ³ <0,84),

Pl (2) - perforated tray in cases where the L value ranges from L = 60 000 to L = 110 000 kg / m ² h.

(AND)

Ugmin = 3.69 X X 10 ⁴ L · ° ^'57 ° _C XF · ⁷ _ ix [χ ίο ^3] - "' X ⁵ [- £ -] ³ x vgl

Pl b (9) (in which —-— X 10 ³ 2 0,84)

Pi (II)

Ugmin = 3.08 ΙΟ X ⁴ X L X ⁵⁷ ° · Fc ^0-7 _ 1

X [X 103] -1.532 χ [—k_] ³ x vTi

Pl b (9)

Pe

Pi (in which χ 10 ³ <0,84) (3) - perforated floor in cases where the L value ranges from L = 110 000 to 250000 kg / m ² h:

(!)

Ug, _nin = 49.14 XF _c ° ' ⁷ X [X 10 ³ ] ⁰ · ⁵ x [1 ³ X Vg 1 (11) (in which —χ 10 ³ and 0.84)

Pi (II)

Ug _min = 40.92 XF _c ° · ⁷ X x 103] -1.535

Ps _ __1_ χ --- ---) ³ χ Vgl (12) (in which - ^p - X 10 ³ <0.84]

Pi (4) - slatted floor in cases where the L value ranges from L = 10 000 to L = 60 000 kg / m ² h:

(AND)

Ug _mi '= 2.33 X ΙΟ ² X L- ° ^08W XF _c

X [- & - X 10 ³ ] - ° ' ⁵⁷⁶ X [—i-] ⁰ ' ²³ X Vgi Pi G (13) (in which ^Ps X 10 ³ and 1.20)

Fri (II)

Ug _m , "= 2.64 X ΙΟ ² XL ^-0 · ⁰⁸⁰⁷ XF _c x [χ ίο ³ ] - ¹ ' ²⁵⁵ x [—B -]" ° · ²³ x g ~ i

Pi G (14) (in which —X 10 ³ <1,20]

Pi (5) - slatted floor · in the case where L value ranges from L = 60 000 to 110 000 kg / m ² h:

(AND)

Ugmin = 5.10 X 104 x L- ⁵⁷ XF _c

X [- ^ - X ΙΟ ^{3] 0576} X (- ^ -] - o 'X ²³ Wi

Pi G (15) (in which - ^p * X 10 ³ and 1,20)

Pi (II)

Ug _mi n = 5.76 X 104 X L - ⁵⁷ XF _c

X [X 10 ³ ] ' ¹ · ²⁵⁵ X [- £ -] - ⁰ · ²³ times higher

Fri L (16)

Ps (in which

Px

X 10 ³ <1.20) (6) - slatted floor in case of rating

L = 250 000 kg / m ² h (AND) Ugmin = 07.8 XF _c X [X 103] -0.576 Pl χ (X VTl (in which —χ 10 ³ > 1.20) Fri (Π) Ugmin = 76.7 _C XF X [X 1O ^{3) 1} · ²⁵⁵ Fri x [θ] ° · ²³ X in g 1 (in which —X 10 ³ <1.20) Fri in which it means

g gravitational acceleration in m / s ² ,

F _c ratio of free area on perforated or slatted floor {-),

L liquid flow rate in kg / m ² s,

G gas flow rate in kg / m ² s, p, liquid density in kg / m ³ , p _g gas density in kg / m ³ = J / —-- capillary constant (mj and surface tension in kg / s ²⁾ .

The term "open area ratio" as used herein refers to the ratio of the total area of openings or slits in square meters per floor to the cross-sectional area of the column in square meters. The above term "surface gas velocity" is defined in this description as the ratio of the instantaneous gas flow rate in m ³ / s of the cross-sectional area of the column in square meters. The unit of said surface gas velocity is therefore m / s.

The operating or working zone of the process of the present invention will be illustrated in detail with reference to the accompanying drawings. It is to be understood, however, that the scope of the present invention is not limited in any way by these figures.

Figure 1 is a graph of the surface gas velocity versus the flow rate of the liquid, showing the working zone A of the process of the present invention when the perforated tray has an F _c value of 0.32 and Figure 2 is a graph of the surface gas flow rate on the flow rate of the liquid, showing the working zone A of the process of the present invention in the case where the perforated tray has an Fc value of 0.52. In Figures 1 and 2, the value of p _s (i.e. gas density) is 1.05 kg / m ³ , and the value of pi (i.e. liquid density)

L ranges from L = 110,000 to (17) (18)

1070 kg./m ³ in FIG. 1, this value in FIG. 2 is a 1000 kg / m ^3.

With the process of the present invention, gases can be efficiently and economically treated with scrubbing liquid at a surface gas velocity ranging from Ug _min to about 8 m / s and in the case of a flow rate of liquid ranging from 10,000 to 110,000 kg / m ² h. The minimum surface velocity of the gas Ug _{mfn of the} present invention is substantially equivalent to the maximum surface velocity of the gas Ugc of the prior art processes. According to the present invention, it has been found that in cases where the gas is treated in countercurrent contact with the scrubbing liquid at a surface gas velocity above Ugc and at a liquid flow rate ranging from 10,000 to 110,000 kg / m ² h in a Morethane tray column having a free area ratio ranging from 0.3 to 0.60, then the specific gaseous component and / or solid component present in said gas can be effectively removed from the gas without rapid pressure drop at the top of the column .

In addition, it should be noted that with the process of the present invention gas can be treated efficiently and economically with scrubbing liquid even in cases where the flow rate of the liquid is greater than 110,000 kg / m ^{2 and} can reach up to 250,000 kg / m ² h, whereas in the prior art the fluid flow rates were limited to between 9000 and 110 000 kg / m ² h. In view of the above, it is clear that the working zone A determined according to the present invention was not known in the prior art, and of the present invention

214999 is therefore a completely unexpected discovery that this zone exists and occurs above the undulation area of prior art processes as well as above said fluid flow rate in prior art processes. That is, the process of the present invention is carried out at a surface gas velocity above the Ugc value above which stable working conditions could not be expected due to the rapid pressure drop increase in Great Britain Patent No. 1,390,163, or according to the present invention to operate in a flow rate range of liquid that is above the values used in the prior art.

The apparatus for carrying out the method, wherein the gas is contacted with the scrubbing liquid, comprises a scrubbing column comprising at least one perforated tray or grate tray having no overflow or downpipes, the ratio of the free area of the tray being in the range of 0 , 30 to 0.60, and preferably from 0.32 to 0.52. The number of trays in the scrubbing column typically ranges from 1 to 7, preferably from 3 to 5, and the spacing of the trays in the column is usually from 0.3 to 5

1.5 m, and preferably 0.5 to 1.2 m. With respect to the floors, there are no requirements for the dimensions of the holes or slots on the trays, but usually the diameter of the holes or the width the slits are selected in the range of 4 to 30 millimeters. The diameter of the shut-off column used to carry out the process of the present invention is typically selected to be 300 millimeters or more, and preferably 500 millimeters or more. In addition, it should be noted that in this case, the upper limit of the purging column diameter is not important and critical. In the practice of the present invention, a scrubbing column having a diameter of approximately 10.3 m was successfully used.

In the case where the ratio of the free area on the trays is less than 0.30, then the surface velocity of the gas in the column is disadvantageously limited by a value of less than 3 m / s since the pressure drop on the palate becomes unacceptably high. This limitation of the surface velocity of the gas, on the other hand, makes it necessary to use disadvantageously large scrubbing columns in the practice of such a procedure. Conversely, if the free area ratio on the palate is greater than 0.60, the tray efficiency is disadvantageously reduced due to the reduced amount of liquid retained on the palate. From a manufacturing point of view, it is also very difficult to produce a tray with a free surface area ratio greater than 0.6.

In the process of the present invention, the flow rate of the liquid to be used as scrubbing liquid is generally in the range of 10,000 to 250,000 kg / m ² h, and preferably in the range of 110 to 250,000 kg / m ² h. 000 to 230 000 kg / m ² h. In a case where the flow amount of liquid that is used as the scrubbing liquid, of less than 10,000 kg / m ² h, the amount of material transferred from the gas into liquid low due to the reduced retention liquids on the floors. On the other hand, if the flow rate of the liquid to be used as scrubbing liquid is greater than 250,000 kg / m ² h, then the pressure drop across the column is relatively high and disadvantageously, a substantial amount of scrubbing liquid is entrained into the gas to be treated.

In carrying out the process according to the invention, the maximum surface velocity of the gas Ug _m and x is about 8.0 m / s, as shown in the attached figures 1 and 2, and preferably 6.0 m / s. When the surface velocity of the gas is greater than 8.0 m / s, not only a disadvantageous pressure drop on the palate drops rapidly, but also the scrubbing liquid tends to entrain the process gas. Under these conditions, a stable continuous process cannot be achieved. Conversely, the minimum surface velocity of the gas Ugmin can be easily calculated according to equations (7) to (18) above, depending on the type of tray used, the flow rate of the liquid and the ratio of density to density of the liquid. In cases where the surface gas velocity is less than Ug _mIn , it is disadvantageous to increase the column diameter in order to process larger quantities of gas on an industrial scale. In cases where the flow rate of the liquid used as scrubbing liquid is in the range of 110,000 to 250,000 kg / m ² h, then the surface gas velocity is usually selected in the range of 2.5 to 8.0 m / s , and preferably in the range of 3.0 to 6.0 m / s, in practice.

In the process of the present invention, the liquid to gas flow ratio [L / G] is typically in the range of 0.5 or more, and preferably in the range of 1.0 above when L value is in the range of 10,000 to L = 60,000 kg / m ² h, further in the range of 2.0 and higher in cases where the L value is in the range of L = 60,000 to L = 110,000

214989 kg / m ^{&lt; 2 &gt};, and in the range of 3.5 and higher in cases where the L value is in the range of L = 110,000 to L = 250,000 kg / m &^lt; ^{2 &gt}; On an industrial scale, the above-mentioned liquid / gas ratio [L / G] in the range of 1 to 17 is preferably selected for the efficient and economical removal of undesirable specific components.

By the process of the present invention, it is possible to treat waste gases containing at least one harmful gaseous and / or solid component selected from the group consisting of sulfur oxides, nitrogen oxides and / or dust particles. Various odorous components can also be treated by the process of the present invention as well as coke oven gas containing various acidic components and / or ammonia gas. The process according to the invention can also be applied to cases in which other types of gaseous components and / or solid components contained in the waste gases must also be removed. The process according to the invention can also be used in cases where the gases are heated or cooled, since a very efficient gas-liquid contact occurs.

The scrubbing or processing liquid used to carry out the process may include all conventional scrubbing solutions or suspensions, all commonly used absorbent solutions or suspensions, and all conventional aqueous solution emulsions. For example, when treating a gas containing sulfur oxides and / or nitrogen oxides, aqueous solutions or suspensions containing alkali metal hydroxides, alkali metal hydroxides or ammonia, such as e.g. sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide or ammonium hydroxide, alkali earth alkaline earth carbonates and ammonium carbonates such as sodium carbonate, potassium carbonate, calcium carbonate, magnesium carbonate or ammonium carbonate, alkali metal sulfites, metal sulfites alkaline earth or ammonium sulfites such as sodium sulfite, potassium sulfite, calcium sulfite, magnesium sulfite, or ammonium sulfite, or the like. The aqueous ammonia solution can be used to remove acidic components from the gas, such as removal of hydrogen sulfide from the coke oven gas. Conversely, in cases where ammonia is removed from the waste gas, sulfuric acid, phosphoric acid, carbolic acid (phenol), acetic acid, oxalic acid, ammonium hydrophosphate or the like can be used for such removal. containing solid particles, such as fine dust or soot particles, then water or water containing any surfactant may be used to physically separate the solid particles from the waste gas. for example sulfur oxides and / or nitrogen oxides, then the above scrubbing or absorbing liquid for removing sulfur oxides and / or nitrogen oxides may act as a solids scrubbing liquid.

The process of the present invention will be further illustrated by the following examples. It should be noted, however, that these examples do not limit the scope of the invention in any way.

He did

The air was countercurrently contacted with water under various conditions, which are shown in Table 1 below, and the contact was made in a column with Morethane trays with a column diameter of 5600 millimeters. and the total number of floors was three, and these floors were without overflow and without downpipes. The free area (F _c ) ratio per floor used in this case was 0.32 or 0.52. The water content of the discharged air from said scrubbing column and the overall pressure drop across said trays were determined under various stable conditions. From the detected water content of the exhaust air, the ratio of the amount of water contained in the exhaust air to the amount of water supplied to the column is calculated. The results obtained are shown in Table 1 below.

214BB9

Table 1

Experiment no.

3

Water flow rate to the column

(kg / m ² h) 40 600 61000 81 200 Free surface area ratio (Fc) 0.32 0.52 0.32 0.52 0.32 0.52 Ratio of the amount of water contained in the discharged air to the amount of water supplied to the column (kg / kg) 0.008 0.008 0.01 0.01 0.03 0.03 Total pressure drop over three floors (Pa) 686.5 1225.9 843.4 1314.1 921.9 1392.6 Surface gas velocity (m / s) 4,5 8.0 4,5 8.0 4,5 8.0 Ugc (m / sec) ⁺ 3.80 6.27 2.96 4.90 2.20 3.67

+ Ugc is calculated from equations (1), (5) and (6) above, where p _g = 1,05 kg / m ³ , pi = 1000 kg / m ³ and 1 = 0, 0038 m.

From the results shown in Table I, it has been found that the surface gas velocities above Ugc (i.e., those above the maximum gas velocity used in the prior art, e.g. U.S. Patent No. 1,390,163) to effect countercurrent contact of gas and liquid on an industrial scale.

Example 2

The procedure was countercurrent with the water under various conditions in Table 2 below, using a scrub column with Morethane trays having a diameter of 5600 millimeters and equipped with four perforated trays without overflow and downpipes. The free floor area ratio used was 0.32 or 0.52. The water content of the discharged air from the scrubbing column, the total pressure drop over the four trays and the surface velocity of the gas in the column were determined under stable operating conditions. From the measured values of the water content of the discharged air, the ratio of the amount of water contained in the discharged air to the amount of water supplied to said scrubbing column was calculated. The results obtained are shown in Table 2.

Water flow rate to the column (kg / m ² h)

Free surface area ratio (Fc)

Ratio of water contained in the discharged air to the quantity of water supplied to the column (kg / kg)

Total pressure drop across four floors (Pa) Surface gas velocity (m / s)

Table 2 Experiment no.

1 2 3 4 5 6 12.2 X 10 ⁴ 16.0 X O 18.0 X 10 ⁴ 0.32 0.52 0.32 0.52 0.32 0.52 0.07 0.08 0.10 0.11 0.24 0.25 186 (3.3 1990,8 2255.6 2304.6 2844,0 2942,1 4,5 8.0 4,5 8.0 4,5 8.0

214869

In addition, further experiments have shown that it is preferable to treat the gas with a liquid under conditions where the surface velocity of the gas is in the range of 2 to 8 m / s and the flow rate of the liquid is in the range of from 110,000 to 170,000 kg / m ² h while achieving more stable process conditions.

Example 3

In this example, 408,000 m ³ / h of contaminated gas was continuously fed from the combustion boiler, which gas contained 1370 ppm of s ^; The column was equipped with four perforated trays with a free-area ratio (Fc) of 0.32, and the diameter of all holes on each floor was about 8.5 millimeters. introduced into the upper end of said scrubbing column 107 60 kg / m ² h of an aqueous absorption liquid containing 0.19 moles / liter of calcium carbonate (CaCos) to countercurrent contact of the sulfur dioxide gas with the carbonate-containing aqueous absorption liquid The surface velocity of the gas in the column was 4.6 m / s and the liquid / gas flow rate [L / G] was 5.7 kg / kg by measuring the sulfur dioxide content of the discharged gases to be treated to determine desulfurization efficiency (i.e. the percentage removed). sulfur dioxide], an average of 90.5%. The total pressure drop across the four trays was 1471.1 Pa. Also, it was observed that there was little entrainment of the absorption liquid and the process could be carried out under stable conditions for a long time.

He attaches

A simulation gas was used which contained approximately 0.4 g / Nm ^{3 of} dust, the dust particles having an average diameter of 20 microns and an actual density of 2.4 g / cm ³ , continuously introduced into the bottom of a 500 millimeter diameter Morethane scrubbing column, the scrubbing column being provided with one perforated tray without overflow and without downcomers. The free area ratio on the palate was 0.34 (Fc) and the diameter of the holes on the palate was approximately 8.5 millimeters. At the same time, 61000 kg / m ² h of water was fed to the upper part of the Morethane scrubbing column, with countercurrent contact of the gas containing the dust particles with water. The surface velocity of the gas in said scrubbing column was 4 m / s and the liquid / gas ratio [L / G] was 3.7 [kg / kg].

The percentage of dust removed from the parent gas was determined from the detected dust content of the treated discharged gas, which was about 99%. The pressure drop on the palate was 343.2 Pa. In addition, it should be noted that only a small amount of water has been observed to be entrained into the discharged gases even though the surface velocity of the gas was above Ugc (i.e. above 3.12 m / s), the maximum gas velocity used for processes according to the prior art.

Example 1 a d 5

In this example, 95,000 m ³ / h of pollutant gas from the combustion boiler, which contained 1700 ppm of sulfur dioxide, continuously fed to the top of a Moretan scrubbing column with a diameter of 2900 millimeters, was provided with four perforated trays without overflow and without downpipes. The free area (Fc) ratio of said perforated trays was 0.52 and the diameter of all holes on said trays was about 10 millimeters. At the same time, 230,000 kg / m ² h of an aqueous absorption liquid solution containing 0.15 g / liter of calcium carbonate (CaCO3) was fed to the top of the scrubbing column to countercurrent contact with the sulfur dioxide gas. , with an aqueous solution of the absorption liquid which contained calcium carbonate. The surface velocity of the gas in said scrubbing column was 4.0 m / s and the ratio of the liquid flow rate L to the gas flow rate G [L / G] was 16 kg / kg.

The desulfurization efficiency was determined from the determined sulfur dioxide content of the discharged process gas, which in this case was 98%. The total pressure drop across the four floors was

1765,3 Pa.

Example 6

600,000 m ³ / h of polluted gas supplied from the iron ore sintering furnace continuously fed to the top of a 10.3 meter Moretan scrubbing column was provided with two perforated trays without overflow and no downpipes, at the same time 90,000 kg / m ² h of an aqueous absorption liquid having a pH of 6.0 containing calcium carbonate (CaCO 3) was continuously fed to the top of said scrubbing column. The free area ratio (F _c ) of said perforated trays in this case was 0.31, and the diameter of the holes on both perforated trays was approximately 8.5 mils (214669 meters). The SO 2 -containing gas was brought in countercurrent contact with the downstream water with an absorption liquid containing CaCO 3 containing the SO 2 from the contaminated gas. The surface velocity of the gas in said scrubbing column was 2.0 m / s and the ratio of the liquid flow rate L to the gas flow rate G [L / G] was 12.5 [kg / kg].

From the measured sulfur dioxide content of the discharged treated gases, the desulfurization efficiency was determined, and in this case the value was 90%. The total pressure drop across the two column trays was in this embodiment

588,4 Pa.

Example 1 a d 7 i:

The procedure was such that 603,000 m ³ / h of polluted gas fed from the iron ore sintering furnace was continuously fed to the top of a 10.3 meter Moretan scrubbing column with two perforated trays without an overflow. without downcomers, at the same time 115 000 kg / m ² h of an aqueous absorption liquid solution having a pH value of 6.0, which contained calcium carbonate CaCO 3, was continuously fed to the top of said scrubbing column. The free area (Fc) ratio on said perforated trays was 0.31 and the diameter of the holes on the two trays was approximately 8.5 millimeters. Sulfur dioxide-containing gas was brought into countercurrent contact with the downstream aqueous solution of the calcium carbonate-containing absorbent liquid to remove the sulfur dioxide contained in the contaminated gas. The surface velocity of the gas in the column was 2.0 m / s and the ratio of liquid flow rate L to gas flow rate G [L / G] was 16 [kg / kg].

The desulfurization efficiency of 93% was determined from the measured sulfur dioxide content of the discharged process gas. The total pressure drop across the two trays was 637.5 Pa. Example 8

In the embodiment of this example, a simulation gas was used which contained approximately 2.4 g / Nm ^{3 of} dust having an average particle diameter of 5.6 microns and an actual density of 3.3 g / cm ³ , which gas was continuously fed to the bottom of a 500 millimeter diameter Morethane scrubbing column, which was provided with three perforated trays with no overflow and no downpipes. The free area ratio (F _c ) on each floor was 0.34 and the diameter of the holes on each floor was about 8 millimeters. At the same time, 123,000 kg / m ² h of water were fed into the upper part of the Moretan column, in which the gas containing the dust particles was countercurrently contacted with water. The surface velocity of the gas in the scrubbing column was 3.73 m / s and the ratio of liquid flow rate to gas flow rate [L / G] was 7.7 [kg / kg].

From the measured dust content of the treated effluent gas, the dust removal ratio was determined to be 92%. The pressure on the palate dropped

1225,9 Pa. In addition, only a small entrainment of water into the discharged gas was observed in the process of this example. ..

Example 1 9

In the embodiment, 408,000 m ³ / h of contaminated gas was supplied from the combustion boiler and containing 1275 ppm of sulfur dioxide continuously fed to the top. the ends of a Moretan scrubbing column with a diameter of 5600 millimeters, equipped with four perforated trays. The individual ratios, the free areas on the above floors were 0.40, 0.32, 0.32 and 0.38, calculated from the bottom. Simultaneously, 130,000 kg / m ^{2 of an} aqueous absorption liquid solution containing 0.08 moles / l calcium carbonate (CaCCb) was fed to the top of the scrubbing column to countercurrently contact the sulfur dioxide-containing gas with the aqueous solution. absorbent liquids containing calcium carbonate. The surface velocity of the gas in the scrubbing column was 4.9 m / s and the ratio of liquid flow rate to gas flow rate [L / G] was 7.0 '[kg / / Kg]. The desulfurization efficiency (i.e. the percentage removal of sulfur dioxide) was determined from the measured sulfur dioxide content of the discharged gases, i.e., the off-gases, and the average value in this case was

93.3%. The total pressure drop across the four floors was 1912.4 Pa. In addition, it has been observed that there is little entrainment of the absorbent liquid and that the process can be carried out under constant conditions for a long time.

Example 10

The process was carried out with 350,000 m &lt; 3 &gt; / h of contaminated gas supplied from the combustion boiler containing 1510 ppm of sulfur dioxide continuously fed to the bottom of a 6600 millimeter diameter Morethane scrubbing column. provided with five perforated floors. The individual open area ratios on the above trays were as follows: 0.32, 0.32, 0.32, 0.32 and 0.35, calculated from the bottom.

Simultaneously, 126,000 kg / m ² h of an aqueous absorption liquid solution containing 0.08 mol / l calcium carbonate (CaCCb) was fed to the top of the scrubbing column to countercurrent contact of the contaminated sulfur dioxide-containing gas with aqueous an absorbent liquid solution containing calcium carbonate. The surface velocity of the gas in said scrubbing column was

2.84 m / s, and the ratio of liquid flow rate to gas flow rate [L / G] was 11.7 [kg / kg]. The desulfurization efficiency of the process was determined from the measured sulfur dioxide content of the treated effluent gases, i.e., flue gases, and was 98.0%. The total pressure drop over the five floors was 1951.6 Pa. In addition, only a small entrainment of the absorbent liquid was observed in the process and could be carried out under stable conditions for a long time.

Claims (4)

OBJECT OF THE INVENTION 1 = y —-—— capillary constant (m) and surface tension in kg / e ² . - ¹ χ t ³ χ Vgl (in which - ^Pg X 10 ³ 0,8 0.84) Fri (Π) Ug _mi '= 40.92 ° _C XF' ⁷ X [- & - X 10 ^{3] 1-535} Pi - ¹ X (—J-1 ^{_ 3} X VgT (in which —- ^IL -X 10 ³ <0.84) Pi - grate deck for cases where the L value ranges from L = 10 000 to L = 60 000 kg / m ² h: (AND) Ug _min = 2.33 X 102 X L-θ ⁰⁸⁰⁷ XF _c < X [- ^ - X ΙΟ ³ ] -θ- ⁵⁷⁶ X [—X Vgl Pi G (in which - X 10 ³ š 1,20) Fri (II) Ugmin = 2.64 X ΙΟ ² X L-0 · ⁰⁸⁰⁷ XF _c X [X 1O ³ ] - ¹ · ²⁵⁵ X [- ^ -] ^ ²³ X fgi pi G (in which —X 10 ³ <1.20) Pi - grate eaitrio for cases where the value of L ranges from L = 60 000 to L = 110 000 kg / m ² h: (AND) Ug _min = 5.10 X 10 4 _X L-0.57 χ _Fc X (- ^ - X 1O ^{3] -0 '576} X [- ^ - ^ϊ'- θ' ²³ X IGL Pl G (in which X ----- 10 ³ 1.20] Fri (II) Ugmin = 5.76 x ΙΟ ⁴ X L- ° ⁵⁷ XF _c X X 103] -1,255 χ [__L _.- J-0.23 χ y-J] Pl G (in which - X 10 ³ <1.20) Piston tray for cases where the value of L ranges from L = 110 000 to L = 250 000 kg / m ² h (AND) Ug _min = 67.8 XF _c X [X 10 ³ ] - ° - ⁵⁷⁶ When χ (-GR ^0-23 χ VTi (in which - ^Pg - ~ X 10 ³ g 1.20) Fri (II) Ug _min = 76.7 XF _C X [X ΙΟ ³ ) - ¹ - ²⁵⁵ Fri X [-1 ~) - o 'νΤι ²³ X (where - ^pg ..... X 10 ³ <1.20) Pi in which g means gravitational acceleration in m / s ² , F _c ratio of free space on perforated floor and on slatted floor (-), L liquid flow rate in kg / m ² s, G gas flow rate in kg / m ² s, Pi density of the liquid in kg / m ³ , p _g density of the gas in kg / m ³ A method for removing contaminants from gases, said components being sulfur oxides, nitrogen oxides, acidic gas components, ammonia gas, dust particles or a mixture thereof, and said gases being, for example, waste gas, coke oven gas, characterized in that the gas is conveyed upward by a scrubbing column with at least one perforated or grate tray without overflow and without downpipes, the free area (Fc) ratio on the palate being in the range of 0.30 to 0.60, and the gas is passed through the scrubbing column at a surface a gas velocity in the range of 8 _min to 8 m / s, and at the same time a scrubbing liquid, which is water or water with a surfactant to physically remove the pollutant, or an absorption liquid for chemical absorption of the pollutants, is fed into the scrubbing column; such as an aqueous solution or suspension of sodium hydroxide, carbonate s potassium hydroxide, potassium carbonate, magnesium hydroxide, magnesium carbonate, calcium hydroxide, calcium carbonate, aqueous ammonia, sulfuric acid, phosphoric acid, carbolic acid, acetic acid, oxalic acid and ammonium phosphate, the liquid flow rate (Lj being in range from 10,000 to 250,000 kg / m ² h, the ratio of liquid flow rate to gas flow rate [L / G] is in the range of 0.5 to 17, and Ugmin is defined by: - perforated floor in cases where the L-value is between L = 10 000 and L = 60 000 kg / m ² h: (AND) Ug _mi '= 1.69 X ΙΟ ² X L- ⁰⁸⁰⁷ XF _c ° · ⁷ X [X 103] -0.5 _xt 3 _χ y ~ [pi G (in which —χ 10 ³ 0,8 0.84} Pi Ug, _nin = 1,41 X ΙΟ ² XL ^-0 - ⁰⁸⁰⁷ XF _c ° - ⁷ _ ¹ χ (χ ίο ³ ] - ¹ ' ⁵³⁵ X ( ³ X VgT pi G (in which —— χ 10 ³ <0, 84), Pi - perforated levels of cases where the L value ranges from L = 60 000 to L - 110 000 kg / m ² h: (AND) Ug, 'in = 3.69 X 104 χ L-0.57 χ p _c o; 7 χ [χ 103] -0.5 χ [_L_] ³ χ y _gl pi g (in which χ 10 ³ g 0.84) Pi (II) Ug = 3.08 _min X ⁴ L ΙΟ ^{-0 '57} ° _C XF - ⁷ __i_ X [X 105] - ¹ - ⁵³⁵ X [- £ -] ³ x Vgl pi G (in which - χ 10 ³ <0.84) Pi - perforated tray for cases where the L value ranges from L = 110 000 to L = 250 000 kg / m ² h: (AND) Ug _mnj = 49.14 XF _c ° - ⁷ X [X 103] -0.5 pl 2. The method of claim 1, wherein the ratio of liquid to gas flow rates [L / G] is in the range of 1 to 17. Method according to claim 1 or 2, characterized in that the upper limit of the surface gas velocity is 6 m / s. 4. Apparatus for carrying out the method according to claims 1 to 3, characterized in that the scrubbing column comprises 3 to 5 perforated or grate trays without overflow and downpipes, the spacing between the individual trays being in the range of 0.5 m to 1.2 m. .