Method for removing particulate matter from an exhaust gas stream

Abstract

The present invention relates to a method for removing particulate matter from a waste gas stream, which comprises a step of treating the waste gas stream by using a scrubbing liquid containing a treatment composition. The treatment composition is a water-soluble polymer-based solution containing a cationic silicate component. The present invention further relates to a scrubbing liquid suitable for use in a wet scrubbing method, which comprises the treatment composition contained in water at a concentration of about 0.01 to about 10 wt / wt%.

Description

Technical Field

[0001] The present invention relates to a method for removing particulate matter from a waste gas stream using a scrubbing liquid comprising a treatment composition comprising a non-water-soluble polymer-based composition containing a cationic silicate component. In particular, the present invention provides a method for removing PM10, PM4, PM2.5, and PM1 particulate matter from a waste gas stream, among other things.

Background Art

[0002] The presence of high levels of particulate matter, particularly fine particulate matter, in the atmosphere is associated with many diseases and even premature death every year. Furthermore, these pollutants have a significant impact on sensitive ecosystems.

[0003] Liquid or solid particles can be removed from a waste gas stream by transferring them to a liquid. The most commonly used liquid is water. Furthermore, it is well known that the particulate collection efficiency of a wet scrubber is directly related to the amount of energy expended in the contact between the waste gas stream and the scrubbing liquid. This, in turn, directly affects the operating cost of a particular scrubbing system.

[0004] Many conventional wet scrubber systems are common in the industry, but there is a need to improve the engagement efficiency between the particles removed from the gas stream and the scrubbing liquid droplets.

[0005] In particular, there is a need to improve these systems for removing fine particulate matter harmful to the human body. There is also a need to improve the efficiency of the scrubbing liquid, thereby reducing the amount of scrubbing liquid used while maintaining or improving the particulate matter removal efficiency.

Summary of the Invention

[0006] According to a first aspect of the present invention, (a) providing a waste gas stream containing particulate matter, and (b) Treating the waste gas stream with a scrubbing liquid to produce a treated gas stream having a particulate matter concentration lower than the particulate matter concentration of the waste gas stream comprising the scrubbing liquid comprising a treatment composition the treatment composition being a polymer-based solution comprising a cationic silicate component There is provided a method for removing particulate matter from a gas stream, wherein the polymer is a water-soluble polymer.

[0007] In one embodiment, the scrubbing liquid is an aqueous solution of the treatment composition.

[0008] In one embodiment, the scrubbing liquid comprises from about 0.01 to about 10 wt / wt% of the treatment composition.

[0009] In another embodiment, the scrubbing liquid comprises from about 90 to about 100 wt / wt% of the treatment composition.

[0010] In a preferred embodiment, the method is a wet scrubbing method, and the wet scrubber device is a device selected from a spray tower, a cyclone spray tower, a dynamic scrubber, a tray tower, a venturi scrubber, and an orifice scrubber.

[0011] In one embodiment, the waste gas stream has a PM10 concentration of from about 5% to about 30 wt / wt% based on the total particulate matter content in the waste gas stream.

[0012] In a preferred embodiment, the removal efficiency of the PM10 fraction is improved by at least 10% compared to the removal efficiency of a method using the same method parameters but without the treatment composition in the scrubbing liquid.

[0013] In a preferred embodiment, the removal efficiency of the PM10 fraction is improved by at least 15%, at least 20%, or at least 30% compared to the removal efficiency of a method using the same method parameters but without the treatment composition in the scrubbing liquid.

[0014] In one embodiment, the waste gas stream has a PM4 concentration of about 5% to about 30 weight / weight% based on the total particulate matter content in the waste gas stream.

[0015] In a preferred embodiment, the removal efficiency of the PM4 fraction is improved by 10% or more compared to the removal efficiency of a method that utilizes the same method parameters but excludes the treatment composition from the scrubbing liquid.

[0016] In a preferred embodiment, the removal efficiency of the PM4 fraction is improved by 15% or more, 20% or more, or 30% or more compared to the removal efficiency of a method that utilizes the same method parameters but excludes the treatment composition from the scrubbing liquid.

[0017] The waste gas stream may be derived from mining operations, grinding operations, general dust control, or incineration or boiling operations.

[0018] In one embodiment, the scrubbing liquid is in a direction opposite to the waste gas stream, in the same direction as the waste gas stream, or perpendicular to the waste gas stream.

[0019] In one embodiment, the treatment composition further comprises a cationic additive component.

[0020] In one embodiment, the cationic additive component is a salt of a compound selected from the group of compound classes comprising thiazole, dithiocarbamate, dithiophosphate, sulfenamide, thiuram sulfide, xanthate, guanidine, and aldehydeamine.

[0021] In one embodiment, the cationic additive component is a salt of a compound selected from the group of compound classes comprising thiazole, dithiocarbamate, dithiophosphate, thiuram sulfide, or combinations thereof.

[0022] In a preferred embodiment, the cationic additive component is a salt of 2-mercaptobenzothiazole (MBT), zinc dibenzyldithiocarbamate (ZBEC), zinc dialkyldithiophosphate (ZBOP), tetrabenzylthiuram disulfide (TBzTD), diisopropylxanthogen disulfide (DIXD) or polysulfide (AS100), or a combination thereof.

[0023] In one embodiment, the salt is a sodium salt or a potassium salt.

[0024] In one embodiment, the cation of the cationic silicate component is a sodium cation or a potassium cation.

[0025] In a preferred embodiment, the water-soluble polymer is an ethylene oxide polymer or a polyvinyl alcohol polymer.

[0026] In a particularly preferred embodiment, the water-soluble polymer is polyethylene glycol.

[0027] In one embodiment, the water-soluble polymer has a molecular weight of 300 g / mol to 10,000,000 g / mol, preferably 500 to 20,000 g / mol, more preferably about 1,000 to 10,000 g / mol.

[0028] According to another aspect of the present invention, there is provided the use of a treatment composition for improving the particulate matter removal efficiency of a wet scrubbing method, the treatment composition comprising a polymer-based solution of a cationic silicate component, the polymer being a water-soluble polymer.

[0029] According to another aspect of the present invention, there is provided a scrubbing liquid suitable for use in a wet scrubbing method, the scrubbing liquid being an aqueous solution of a treatment composition at a concentration of about 0.01 to about 10 weight / weight% of the scrubbing liquid, the treatment composition comprising a polymer-based solution of a cationic silicate component, the polymer being a water-soluble polymer.

Brief Description of the Drawings

[0030] The present invention will be described in more detail below with reference to the following non-limiting embodiments and figures.

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Mode for Carrying Out the Invention

[0031] Hereinafter, the present invention will be more fully described with reference to the accompanying drawings showing some of the non-limiting embodiments of the present invention.

[0032] The present invention described below should not be construed as being limited to the specific embodiments disclosed, and includes certain modifications and other embodiments intended to be included within the scope of the present invention.

[0033] Certain terms are used in this specification, but these are used only in a general and explanatory sense and are not intended for limitation.

[0034] As used in this specification, throughout the specification and the claims that follow, the singular forms "a", "an", and "the" include the plural unless the context clearly indicates otherwise.

[0035] The terms and expressions used in this specification are for purposes of explanation and should not be regarded as limiting. The use of the terms "comprising~", "containing~", "having~", "including~", and their variants as used in this specification means including the items listed thereafter, and their equivalents, as well as additional items.

[0036] As used herein, the term "particulate matter" should be understood to mean a mixture of solid particles and liquid droplets suspended in air, and in particular, in this context, those suspended in an exhaust gas stream.

[0037] As used herein, the terms "PM10", "PM4", "PM2.5", "PM1", and "PM0.5" should be understood to mean particulate matter having a nominal aerodynamic diameter of 10 μm or less, 4 μm or less, 2.5 μm or less, 1 μm or less, and 0.5 μm or less, respectively.

[0038] As used herein, the term "wet scrubber" should be understood to mean an air pollution control device that removes particulate matter and / or acid gas from an exhaust gas stream. The pollutants are mainly removed by collision, diffusion, interception, and / or absorption of the pollutants into liquid droplets. The liquid containing the pollutants is generally recovered for further treatment and / or disposal. The term "wet scrubbing" as used herein should be understood to be a method of removing particulate matter and acid gas from an exhaust gas stream using a wet scrubber, unless the context clearly indicates otherwise.

[0039] As used herein, the term "scrubbing liquid" should be understood to mean a liquid that is used in a wet scrubber or a wet scrubbing process and that interacts with particulate matter and / or acid gas in a waste stream. The scrubbing liquid may contain one or more additives to improve the efficiency of the wet scrubbing system.

[0040] As used herein, the term "water-soluble polymer" should be understood to mean a polymer that dissolves, disperses, or swells in water, including polymers containing hydroxyl groups, such as ethylene oxide type polymers or polyvinyl alcohol polymers.

[0041] As used herein, the term "beta value" should be understood to mean a value for a particular scrubbing system defined as the number of particles exiting the system per 100 particles entering the system. For example, in a system where 15 particles exit the system for every 100 particles entering the system, the beta value is 6.67. Alternatively, the efficiency of the same system may be reported as 85%.

[0042] The present invention provides a method for removing particulate matter from a waste gas stream, the method utilizing a scrubbing liquid comprising a treatment composition. The present invention further relates to such a scrubbing liquid composition.

[0043] The inventors have surprisingly found that a scrubbing liquid comprising a treatment composition comprising a water-soluble polymer-based composition comprising a cationic silicate component improves the particulate matter removal efficiency of the scrubbing liquid, thereby improving the overall method. These treatment compositions have shown surprising and unexpected results as additives to scrubbing liquids used in the removal of particulate matter from waste gas streams or in methods for the removal of particulate matter from waste gas streams.

[0044] The treatment composition can be dissolved in the scrubbing liquid to form a solution of the treatment composition in the scrubbing liquid at a concentration of about 0.01% or more. The treatment composition can be dissolved, for example, in water to form an aqueous solution of the treatment composition at a concentration of about 0.01 weight / weight% to about 10 weight / weight% relative to the scrubbing liquid. Other examples of the treatment composition in the scrubbing liquid depend on the waste gas stream, the source of the particulate matter, and the standard operating parameters of a particular method. Such further examples are defined by routine experimentation by those skilled in the art having the benefit of the teachings of this disclosure.

[0045] The treatment composition may further include a second cationic component that is referred to in this specification as a cationic additive component (in addition to the cationic silicate component), is dissolved in the combination of the cationic silicate-polymer, and is thereby stabilized. The second cationic component, or the cationic additive component, may be, for example, a metal salt of a metal oxide such as zinc oxide, or a cationic nanopowder such as reduced graphene oxide.

[0046] The salt of the cationic additive component may be a salt of a compound selected from the group of compound classes including thiazole, dithiocarbamate, dithiophosphate, sulfenamide, thiuram sulfide, xanthate, guanidine, aldehydeamine, or combinations thereof.

[0047] The polymer in the treatment composition is a water-soluble polymer, for example, an ethylene oxide type polymer, a polyvinyl alcohol polymer, or other polymers containing a hydroxyl group.

[0048] The water-soluble polymer-based treatment composition may be prepared as follows. A suitable cationic silicate component solution is synthesized by dissolving silica powder in a basic solution, such as sodium hydroxide or potassium hydroxide. The obtained cationic silicate component may be added to a water-soluble polymer, such as an ethylene oxide polymer containing polyethylene glycol, and dried to produce a stable ionic solution or ionic liquid of a specific cationic silicate component.

[0049] Instead of an aqueous environment, a specific combination of a cationic silicate component and a polymer, such as polyethylene glycol, enables an appropriately stable ionic solution to be obtained. This means that it enables greater reactivity and potential as a reactive solvent medium and stabilizer for the additional cationic additive component desired in the final treatment composition.

[0050] These combinations or complexes of cationic silicate solutions and the resulting cationic silicate polymers can be prepared by reacting different ratios of selected cations with silica, thereby assuming a change in the surface chemistry and ionic nature of the solution and the resulting treatment composition. In one embodiment of the present invention, a stoichiometric ratio of cation to silica may be used. Alternatively, this ratio may be varied according to the requirements of a particular system and the particulate matter to be removed from the flue gas stream.

[0051] The cationic silicate component may be prepared in water or in a suitable azeotrope of water and alcohol, preferably water and isopropyl alcohol.

[0052] In one embodiment of the present invention, the composition may further comprise, as a cationic additive component, a salt of a compound dissolved in a cationic silicate component and a polymer carrier. The cationic additive complex may be prepared in an aqueous caustic solution, such as a solution of sodium hydroxide or potassium hydroxide. The cationic additive complex may be prepared by dissolving sodium hydroxide or potassium hydroxide in water prior to reacting with the compound.

[0053] The cationic additive complex may be prepared in a suitable azeotrope of water and alcohol. In a preferred method of the present invention, the cationic additive complex is prepared in a water-isopropyl alcohol azeotropic mixture.

[0054] The cationic additive may be based on salts of compounds selected from the group of compound classes including thiazole, dithiocarbamate, dithiophosphate, sulfenamide, thiuram sulfide, xanthate, guanidine, aldehydeamine, or combinations thereof.

[0055] In one embodiment, the compound of the cationic additive is a compound selected from the group of compound classes including thiazole, dithiocarbamate, dithiophosphate, thiuram sulfide, or combinations thereof. Preferably, the salt is the sodium salt or potassium salt of 2-mercaptobenzothiazole (MBT), zinc dibenzyldithiocarbamate (ZBEC), zinc dialkyldithiophosphate (ZBOP), tetrabenzylthiuram disulfide (TBzTD), diisopropylxanthogen disulfide (DIXD) or polysulfide (AS100), or combinations thereof.

[0056] Add the aforementioned cationic additive, or other suitable ionic substances such as metal salts, metal oxides, nano powders, etc. to the cationic silicate solution to prepare a reaction mixture with an aqueous polymer added. Then, dry the resulting reaction mixture to remove the solution medium, especially water from the system. In one embodiment, the mixture may be dried under vacuum, for example, at 100 mBar or less, to remove the solution medium. The resulting composition is a non-aqueous composition based on a water-soluble polymer, such as polyethylene glycol.

[0057] The cationic additive component and the cationic silicate component may constitute about 50% of the total mass of the polymer-based composition, and the aqueous polymer component constitutes the remainder of the scrubbing liquid treatment composition.

[0058] The scrubbing liquid treatment composition is expected to find use in any wet scrubber device including a spray tower, cyclone spray tower, dynamic scrubber, tray tower, venturi scrubber, orifice scrubber, or any combination of the principles underlying these devices. Further, the interaction of the scrubbing liquid and the waste gas stream containing particulate matter can take several configurations. The system can be adapted to interactions in a direction opposite to the waste gas stream, the same direction as the waste gas stream, or a direction perpendicular to the waste gas stream. In the following examples, the interaction was in substantially the same direction as the waste gas stream.

[0059] The configuration of the wet scrubber used in the following embodiments is shown in FIG. 1. Referring to FIG. 1, the waste gas stream enters the wet scrubber 10 at the inlet (or entry point) 12. The scrubbing liquid supply is carried out through port 20, and the particulate matter filter screen 30 is provided downstream of the inlet 12 and the scrubbing liquid port 20. The particulate matter sensors 40, 42, 44 are provided at various locations in the system. Sensor 40 (hereinafter, "ZNeck") is located in the region generally called the neck of the system, after the inlet 12 and before the port 20, sensor 42 (hereinafter, "ZUp") is located upstream of the screen 30, and sensor 44 (hereinafter, "ZDown") is located downstream of the screen 30.

Example

[0060] Next, the present invention will be described in more detail with reference to the following non-limiting examples and experimental results.

[0061] (Experimental Example 1): Preparation of a sodium silicate / polyethylene glycol composite scrubbing liquid treatment composition In a suitable container, 10 g of NaOH was added to 40 mL of water. To this solution, 7.5 g of silica powder was added with stirring. The solution was heated to 60 °C and it was confirmed that dissolution proceeded rapidly (since the reaction is exothermic, heating is not very necessary). The solution was stirred at 60 °C for 5 minutes. This solution becomes transparent when the reaction of NaOH and SiO2 is complete.

[0062] 2NaOH + SiO2 → Na2SiO3(aq) + H2O

[0063] The sodium silicate solution may also be prepared in a suitable azeotropic mixture, for example, a mixture of water and isopropyl alcohol.

[0064] 15 g of polyethylene glycol was added to this solution. The amount of PEG is usually the same mass as the content of the silicate. The solution was stirred at 60 °C for 5 minutes until all the PEG was dissolved. The solution was dried at 105 °C and below 100 mBar to obtain an amber transparent sodium silicate - polyethylene glycol composition.

[0065] In the following examples, the above sodium silicate - polyethylene glycol composition is referred to as "PEGSIL".

[0066] (Experimental Example 2 (Control)): Coal particulate matter control, water only In this control experiment, water was used as the scrubbing liquid. The waste gas stream contained sized coal particulate matter with a particle size cumulative distribution function ("CDF") as shown in Figure 2. The distribution of the coal particulate matter is represented as the CDF, and the CDF in the region specific to the Sensirion sensor (0.5 μm to 10 μm) is shown in Figure 3. The Sensirion particle sensors were placed at the positions of ZNeck, ZUp, and ZDown as described above.

[0067] Regarding the mass flow of coal flowing into the system, the total removal amount of each system is determined by using the known mass distribution of the coal and calibrating the relative counts measured by the downstream sensors. The coal CDF of PM4 was about 15% of the total mass of the coal particulate matter entering the scrubbing system.

[0068] The standard water flow rate was 15 LPM to 33 LPM, and the air flow rate was 30 m / s.

[0069] The results regarding the removal of coal fine particles from the waste gas stream by using water as the scrubbing liquid are shown in Figures 4 and 5. As can be seen from these figures, when comparing the values of ZNeck with ZUp and further with ZDown located downstream of the filter screen, the fractions of PM10, PM4, PM2.5, and PM1 seem to be increasing. Without wishing to be bound by a particular theory, this is presumably due to the coal particles themselves and the result of the collision between the coal particles and the water droplets, which led to an increase in the number of fine particles in these size ranges.

[0070] The total amount of coal discharged from the scrubbing system is about 30% of the total amount of coal entering the system, and the beta value of coal particles in this size range is 3.33 (efficiency 70%).

[0071] (Experimental Example 3): Coal particulate matter control, water with PEGSIL added In this experiment, the scrubbing liquid was water containing PEGSIL as the treatment composition, and the addition amount of PEGSIL to the aqueous system was 0.1% by mass. The waste gas stream contained the same classified coal particulate matter as in Comparative Experiment 1. The Sensirion particle sensor was placed at the positions of ZNeck, ZUp, and ZDown as described above.

[0072] Regarding the mass flow rate of coal flowing into the system, the total removal amount of each system was determined by using the known mass distribution of coal and calibrating the relative count number measured by the downstream sensor. The CDF of PM4 coal was about 15% of the total mass of coal particulate matter entering the scrubbing system.

[0073] The standard scrubbing liquid flow rate was 15 LPM to 33 LPM, and the air flow rate was 21 m / s as measured by an anemometer immediately upstream of the intake fan. The air flow rate was maintained at the normal flow rate for the system to determine the actual volume and intake amount of particulate matter.

[0074] The results of removing coal fine particles from the waste gas stream using water as the scrubbing liquid are shown in FIGS. 6 and 7.

[0075] In Experiment 1 (Figure 4), the particulate screen removed approximately 39% of the PM4 particulates (i.e., particles 4 μm and smaller). As can be seen from Figures 6 and 7, the system using the scrubbing liquid with the treatment composition added reduced the PM4 particulate count before the screen by approximately 35% (comparison of the PM4 values of ZUp in Figures 4 and 5). Although not wishing to be bound by any particular theory, this result is obtained as a result of excellent wetting, and it is considered that the coal particulate matter is removed from the gas stream by gravity. Therefore, it can be seen that the scrubbing liquid added (or doped) with the PEGSIL treatment composition without using a particulate screen is as effective as the particulate screen in a comparative experiment reflecting a standard water scrubbing coal operation. Furthermore, the scrubbing liquid with the PEGSIL treatment composition added reduces the number of particulate matters after the screen by approximately 48.5% compared to the comparative experiment, which is considered to be the result of further interaction and wetting on the screen support. The scrubbing liquid with the PEGSIL treatment composition added reduced the total particulate matter count by 50% compared to the water scrubbing system.

[0076] The total amount of coal exiting the scrubbing system was approximately 15% of the total amount of coal entering the system, and the beta value was 6.66 (efficiency 85%).

[0077] (Experimental Example 4): Polyhalite Scrubbing In this series of experiments, the scrubbing performance of water was compared with the use of water with 0.1 wt / wt% PEGSIL added as the scrubbing liquid. The waste gas stream contained polyhalite, which is a mineral containing hydrated sulfates of potassium, calcium, and magnesium, and has the formula K2Ca2Mg(SO4)4·2H2O.

[0078] The experiments were conducted at 15 L / min (「LPM」), 22 LPM, and 33 LPM. The mass numbers of particulate matters of different particle sizes were measured at ZNeck, ZUp, and ZDown. Subsequently, the beta value and the efficiency Eta were determined.

[0079] Typical graphs measured for the water and PEGSIL addition systems at 33 LPM are shown in Figures 8 and 9, respectively.

[0080] The obtained results and efficiencies of the scrubbing systems with water and PEGSIL added are summarized in Figures 10 and 11. As can be seen from these figures, the system using water with 0.1 wt / wt% PEGSIL-treated composition added as the scrubbing liquid significantly outperformed the standard water scrubbing system.

[0081] The efficiency of each system is represented by the beta values in Table 1 below. As is clear from the beta values shown in Table 1, the PEGSIL addition (or doped) system brings about a significant efficiency improvement over water alone at each flow rate and each particulate matter fraction tested. What this result implies is that by using a scrubbing system with PEGSIL added, it may be possible to significantly reduce the use of water while maintaining the control of particulate matter, or it may be possible to provide more efficient control of particulate matter at the same flow rate as a standard scrubbing system. JPEG2025524188000001.jpg81162

[0082] (Experimental Example 5): Scrubbing of high-silica-containing particulate matter, PEGSIL-added water In this experiment, the scrubbing liquid was again water with PEGSIL added as the treatment composition at a PEGSIL amount of 0.1 wt / wt%. The efficiency of the scrubbing system with PEGSIL added was compared with that of scrubbing using only water. The waste gas stream contained high-silica-containing particulate matter obtained from a gold mining operation in South Africa.

[0083] The particle size distribution of the high-silica-containing particulate matter is shown in Fig. 12. The region important for the wet scrubber is the particulate matter that may float in the air, which is generally a substance with a radius of less than 75 μm called the "floating (or float)" region. As can be seen from Fig. 12 (CDF of silica particulate matter in the floating region), about 11.5% of the particulate matter in this sample was in the respirable range that is toxic to all silica.

[0084] The high-silica-containing particulate matter was introduced as described above, and the system was allowed to reach a steady state. In these experiments, different flushing times with clean water as the scrubber liquid were used to examine the potential effect of PEGSIL on the scrubber mesh. Table 2 below shows the beta values of Tests 1 to 6 conducted in this series of experiments. JPEG2025524188000002.jpg77166

[0085] As can be seen from the results summarized in Table 2, at the complete steady saturation state (Test 4), the beta value when using water with PEGSIL added (0.1 wt / wt%) was much higher than the beta value obtained when using water as the scrubbing liquid. Test 5 shows how the scrubbing performance begins to decline as PEGSIL is washed out of the system, and Test 6 shows the final performance of only the aqueous system where all PEGSIL was washed out of the mesh screen and no longer present in the system. The results of Tests 4, 5, and 6 are summarized in Fig. 13, where Test 6 shows the water baseline and Test 4 shows the optimal operating value for PEGSIL-added scrubbing of high-silica-containing particulate matter.

[0086] Some of the above descriptions of the exemplary embodiments of the present invention are for showing how the present invention can be manufactured and implemented. Those skilled in the art may change various details and thereby reach further embodiments, but it can be seen that many of these embodiments are within the scope of the present invention.

Description of Reference Numerals

[0087] 10 … Wet scrubber 12 … Inlet 20 … Scrubbing liquid port 30 … Particulate matter filter screen 40, 42, 44 … Particulate matter sensor

Claims

1. (a) providing a waste gas stream containing particulate matter, and (b) treating the waste gas stream with a scrubbing liquid to produce a treated gas stream having a particulate matter concentration lower than the particulate matter concentration of the waste gas stream comprising the scrubbing liquid comprising a treatment composition, the treatment composition being a polymer-based solution containing a cationic silicate component, the polymer being a water-soluble polymer, a method for removing particulate matter from a gas stream.

2. The method according to claim 1, wherein the scrubbing liquid is an aqueous solution of the treatment composition.

3. The method according to claim 2, wherein the scrubbing liquid comprises from about 0.01 to about 10 wt / wt% of the treatment composition.

4. The method according to claim 1, wherein the scrubbing liquid comprises from about 90 to about 100 wt / wt% of the treatment composition.

5. The method is a wet scrubbing method, and the wet scrubber device is a device selected from a spray tower, a cyclone spray tower, a dynamic scrubber, a tray tower, a venturi scrubber, and an orifice scrubber. The method according to any one of claims 1 to 4.

6. The method according to any one of claims 1 to 5, wherein the waste gas stream has a PM10 concentration of from about 5% to about 30 wt / wt% based on the total particulate matter content in the waste gas stream.

7. The method according to claim 6, wherein the removal efficiency of the PM10 fraction is improved by 10% or more compared to the removal efficiency of a method using the same method parameters but with the treatment composition removed from the scrubbing liquid.

8. The method according to claim 6, wherein the removal efficiency of the PM10 fraction is improved by 15% or more, 20% or more, or 30% or more compared to the removal efficiency of a method using the same method parameters but with the treatment composition removed from the scrubbing liquid.

9. The method according to any one of claims 1 to 8, wherein the waste gas stream has a PM4 concentration of from about 5% to about 30 wt / wt% based on the total particulate matter content in the waste gas stream.

10. The method according to claim 9, wherein the removal efficiency of the PM4 fraction is improved by 10% or more compared to the removal efficiency of a method using the same method parameters but with the treatment composition removed from the scrubbing liquid.

11. The method according to claim 9, wherein the removal efficiency of the PM4 fraction is improved by 15% or more, 20% or more, or 30% or more compared to the removal efficiency of a method that uses the same method parameters but excludes the treatment composition from the scrubbing liquid.

12. The method according to any one of claims 1 to 11, wherein the waste gas stream is derived from a mining operation, a grinding operation, general dust control, or an incineration or fluidized bed operation.

13. The method according to any one of claims 1 to 12, wherein the scrubbing liquid is in a direction opposite to the waste gas stream, in the same direction as the waste gas stream, or perpendicular to the waste gas stream.

14. Use of a treatment composition for improving the particulate matter removal efficiency of a wet scrubbing method, wherein the treatment composition comprises a polymer-based solution of a cationic silicate component and the polymer is a water-soluble polymer.

15. The use according to claim 14, wherein the treatment composition further comprises a cationic additive component.

16. The use according to claim 15, wherein the cationic additive component is a salt of a compound selected from the group of compound classes comprising thiazole, dithiocarbamate, dithiophosphate, sulfenamide, thiuram sulfide, xanthate, guanidine, and aldehydeamine.

17. The use according to claim 15, wherein the cationic additive component is a salt of a compound selected from the group of compound classes comprising thiazole, dithiocarbamate, dithiophosphate, thiuram sulfide, or combinations thereof.

18. The use according to any one of claims 15 to 17, wherein the cationic additive component is a salt of 2-mercaptobenzothiazole (MBT), zinc dibenzyldithiocarbamate (ZBEC), zinc dialkyldithiophosphate (ZBOP), tetrabenzylthiuram disulfide (TBzTD), diisopropylxanthogen disulfide (DIXD) or polysulfide (AS100), or combinations thereof.

19. The use according to any one of claims 16 to 18, wherein the salt is a sodium salt or a potassium salt.

20. The use according to any one of claims 14 to 19, wherein the cation of the cationic silicate component is a sodium cation or a potassium cation.

21. The use according to any one of claims 14 to 20, wherein the water-soluble polymer is an ethylene oxide polymer or a polyvinyl alcohol polymer.

22. The use according to claim 21, wherein the water-soluble polymer is polyethylene glycol.

23. The use according to any one of claims 14 to 22, wherein the water-soluble polymer has a molecular weight of 300 g / mol to 10,000,000 g / mol, optionally 500 to 20,000 g / mol, and optionally about 1,000 to 10,000 g / mol.

24. A scrubbing liquid suitable for use in a wet scrubbing method, wherein the scrubbing liquid is an aqueous solution of a treatment composition having a concentration of about 0.01 to about 10% by weight / weight of the scrubbing liquid, the treatment composition comprising a polymer-based solution of a cationic silicate component, and the polymer being a water-soluble polymer.

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