KR19990009359A - Granular composite molecular sieve for deodorant and its manufacturing method - Google Patents

Abstract

The present invention relates to a granular composite molecular sieve for a deodorant and a method for manufacturing the same, and more particularly, to a composite molecular sieve composition in which an alkali metal silicate aqueous solution is granulated by granulating a mixture of various types of zeolite and activated carbon, thereby granulating copper, iron, and zinc. And by adsorbing active metals such as aluminum, the adsorption characteristics of adsorption and removal of odor-causing gas is excellent, it is possible to use for a long time by a significant increase in the amount of adsorption, and has a very useful characteristics such as freshness retention function in food use The present invention relates to a granular composite sieve for deodorant and a method for producing the same, which are useful for odor removal and air purification generated in food waste disposal systems, chemical plants and animal kennels.

Description

Granular composite molecular sieve for deodorant and its manufacturing method

The present invention relates to a granular composite molecular sieve for a deodorant and a method for manufacturing the same, and more particularly, to a composite molecular sieve composition in which an alkali metal silicate aqueous solution is granulated by granulating a mixture of various types of zeolite and activated carbon, thereby granulating copper, iron, and zinc. And by adsorbing active metals such as aluminum, the adsorption characteristics of adsorption and removal of odor-causing gas is excellent, it is possible to use for a long time by a significant increase in the amount of adsorption, and has a very useful characteristics such as freshness retention function in food use The present invention relates to a granular composite sieve for deodorant and a method for producing the same, which are useful for odor removal and air purification generated in food waste disposal systems, chemical plants and animal kennels.

In the present invention, the term 'deodorant' refers to hydrogen sulfide, mercaptans, amines, and other irritating gaseous substances defined as odors in the Air Quality Preservation Act to remove an unpleasant odor and disgust. Refers to the material used. Odors are usually caused by a mixture of several compounds, all of which not only cause an unpleasant odor, but also adversely affect the human body.

Known deodorization methods so far known include a method of using a masking agent that exhibits a bad smell concealment effect by spraying a strong aroma to the deodorizing source, a method of neutralizing the odor component by volatilizing the neutralizing agent to a certain concentration in the air, activated carbon, silica gel and The method of adsorb | sucking a deodorizing source using molecular sieves, such as a zeolite, is used.

Among the deodorizing methods, the masking agent may be harmful to the human body due to strong fragrance, and the neutralization method using the volatilization method may have an odor, and the neutralizer itself may have an odor and disappear regardless of the concentration of the target gas. There is a danger of harm. As a typical deodorization method, adsorption using molecular sieve is adopted.

Zeolite as a deodorizing molecular sieve is crystalline aluminosilicate represented by the following formula (1).

M _{x / n} [(AlO ₂ ) _x (SiO ₂ ) _y ] · wH ₂ O

In Formula 1, M is a cation; n is valency; w represents a molecule of crystal water; x and y are constants depending on the crystal structure of the zeolite.

In general, zeolites have a pore diameter of about 3 to 10 Å, which shows a molecular sieve effect. Especially, as a hydrophilic adsorbent, zeolite has strong adsorption to polar molecules such as water, and has excellent adsorption power under low partial pressure and high temperature. Indicates. In addition, the zeolite has an ion exchange ability, so that it can be exchanged with alkali metals, alkaline earth metals, transition metals, and the like in an aqueous solution, and has been used as a catalyst or an ion exchanger in the past because it significantly increases the adsorption capacity when exchanged with these specific components.

On the other hand, activated carbon is produced by activating in a reducing atmosphere during the process of carbonizing coconut shell, coal-based, wood, etc., the form is granular, crushed and powdery form, the pore diameter is 1 ~ 100 ㎚, mostly 2 ㎚ It consists of the following fine pores. Activated carbon is a lipophilic adsorbent, and the adsorption power of nonpolar molecules is strong, and the specific surface area is not particularly limited, but it is most preferable to have 800 to 1400 m 2 / g. Such activated carbon is a typical malodor adsorbent and is known to exhibit a universal adsorption removal effect for a wide range of malodorous caustic gases. However, although adsorption performance is effective for adsorption of nonpolar hydrocarbons such as benzene and toluene, there is a disadvantage in that it does not exhibit sufficient adsorption capacity for odor gas containing low boiling point compounds such as ammonia or polar molecules.

Recently, in order to supplement the mutual adsorption capacity of zeolite, which is a hydrophilic adsorbent, and activated charcoal, which is a lipophilic adsorbent, a method of preparing an adsorbent having a mixed function by using a mixture of zeolite and activated carbon, and an activated carbon, a zeolite, or an analog thereof Many methods have been reported for the preparation of combined or silicate compounds and activated carbon mixed compositions.

For example, Japanese Laid-Open Patent Publication No. 54-53669 discloses a method for producing ozone decomposition products by adding and molding bentonite and sugar to a zeolite and activated carbon mixture, followed by drying and firing. However, since the manufacturing method uses bentonite, which is a natural clay, as an inorganic binder, the impregnated impurities are contained in the product as it is, and since the natural clay-based binder used as the binder is insoluble in water, plasticity is reduced when mixed with water. Since moldability becomes poor, there is a disadvantage in that plasticity is maintained by adding a compound of a water-soluble polymer system, which is an organic binder, in order to mold to a desired shape. In addition, bentonite swells in water, and thus annealing of the composition is prevented. In order to carbonize the sugar component as an organic binder, the bentonite must be dried and calcined under a reducing atmosphere. As a result, complex calcination equipment and enormous energy are required, and manufacturing cost increases, and shrinkage of bentonite due to calcination decreases abrasion resistance of the granular composition, which causes severe dust generation, and decreases specific surface area. Since a large amount of volatile components are generated in the carbonization process to cause air pollution, many problems have been pointed out in the manufacturing process, such as requiring a separate treatment system.

Meanwhile, a method of preparing an oil-absorbing water treatment agent by adding blast furnace slug powder to zeolite is reported in Japanese Patent Application Laid-Open Publication No. 4-4039. This technique causes ecological safety problems of blast furnace slug components and does not have good moldability. There was a problem that the granulation process was not easy and the lipophilic adsorption characteristics were low.

In addition, a method for preparing a filter adsorbent by adding silicate to activated carbon is reported in Japanese Patent Application Laid-Open No. 59-69146. This technique also has a possibility of clogging activated carbon pores by silicate and hydrophilicity due to molecular sieve effect. There was a problem of low adsorption capacity.

In order to solve the problems of the prior art, the present applicant has filed a patent application for a composite molecular sieve incorporating an alkali binder, an alkaline binder, and an organic binder, molasses, in an zeolite and activated carbon mixture to improve product formability and wear resistance. Republic of Korea Patent Application No. 94-18327], this technology also undergoes a sintering process during the process, which is still causing the above problems and there was a limit in the improvement of adsorption capacity and specific surface area.

Therefore, the present inventors have made efforts to develop a deodorant having a wide range of deodorizing performance to improve the above problems, and as a result, a zeolite which adsorbs hydrophilic and polar molecules well and activated carbon having excellent performance in adsorbing lipophilic and nonpolar compounds are properly combined. The present invention was completed by supporting the active metal component on its own or in combination to produce a granular composite molecular sieve for a deodorant that was given a significantly increased adsorption capacity and selectivity for a particular component.

Accordingly, an object of the present invention is to provide a granular composite molecular sieve for a deodorant and a method for producing the same, which have hydrophilic and lipophilic, polar and nonpolar adsorption capacities, and have broad characteristics.

The present invention is a granular composite sieve for deodorant, 10 to 70% by weight zeolite, 10 to 70% by weight activated carbon, 10 to 35% by weight alkaline earth metal silicate, and at least one active metal selected from copper, zinc, iron and aluminum It is characterized by the granular composite molecular sieve for deodorant in which 2 to 30 wt% is granulated.

In addition, the present invention is a method for producing a granular composite molecular sieve for deodorant,

Granulating by injecting and kneading an aqueous alkali metal silicate solution into a mixture of zeolite and activated carbon; And

After the addition of the aqueous alkaline earth metal salt solution to the granulated composition, a method for producing a granular composite molecular sieve for deodorant comprising the step of supporting at least one active metal selected from copper, zinc, iron and aluminum.

Referring to the present invention in more detail as follows.

The present invention granulates the mixture of zeolite and activated carbon using an aqueous alkali metal silicate solution having excellent moldability as an inorganic binder, and granulates the aqueous alkaline earth metal salt solution without drying or calcining and without using a separate organic binder. Water-soluble alkali metal silicate used as an inorganic binder in addition to the above-mentioned composition is converted into alkaline earth metal silicate insoluble to water to increase the wear resistance of the granular composite molecular sieves, to prevent the annealing in the aqueous solution, and the binder itself has adsorption characteristics. At the same time, the zeolite contained in the granulated composition is converted into an alkaline earth metal zeolite, and the specific surface area of the granular composite molecular sieve is significantly increased, and further, copper, iron, zinc, aluminum Active gold In the physical and chemical adsorption characteristics will appear as a combination of polar molecules, as well as exhibits a big absorption capacity or the like of unsaturated fatty acids related to the composite particulate deodorant minutes for the increasing the adsorption capacity of various odor gas itself.

Hereinafter, the method for preparing the granular composite molecular sieve for deodorant according to the present invention will be described in detail for each process.

The first step is granulation by injecting and kneading an aqueous alkali metal silicate solution into a mixture of zeolite and activated carbon.

Zeolite powder and powdered activated carbon were placed in a flow share mixer, sufficiently mixed at a speed of 100 to 300 rpm for 2 to 30 minutes, and subsequently kneaded while spraying an alkali metal silicate aqueous solution through a nozzle, followed by mixing the mixture at 0.2 to 5 Granulate to mm size.

The zeolite used in the present invention can be used in the form of powder, in addition to the 4A type, X, Y and ZSM type zeolites or natural zeolites. The zeolite is preferably used within the range of 10 to 70% by weight based on the total components constituting the granular composite molecular sieve of the present invention. When the amount of the zeolite is less than 10% by weight, the binding strength is weakened and the hydrophilic adsorption characteristics are lowered. If it exceeds%, the lipophilic adsorption characteristic is lowered.

In addition, activated carbon may be produced by using coconut shell as a raw material in powder form having a specific surface area of 1000 m 2 / g or more, preferably 1000 to 1200 m 2 / g, bituminous carbon-based and wood-based activated carbon. Activated carbon is preferably used within the range of 10 to 70% by weight with respect to the total components constituting the granular composite molecular sieve of the present invention. When the amount of the activated carbon is less than 10% by weight, the lipophilic adsorption characteristics are lowered, and 70% by weight is used. If it exceeds, hydrophilic adsorption capacity will fall and it will be difficult to obtain the granular composition which has a desired wear resistance.

As the alkali metal silicate, for example, sodium silicate, potassium silicate and the like are used, but an aqueous solution containing 15 to 38% by weight of sodium silicate having a molar ratio of SiO ₂ / Na ₂ O of 2.2 to 3.8 is preferably used. Alkali metal silicate is preferably used within the range of 10 to 35% by weight with respect to the total components constituting the granular composite molecular sieve of the present invention. When the amount of the alkali metal silicate is less than 10% by weight, the bonding strength is weak and the wear resistance and hardness are weak. If it exceeds 35% by weight, the micropores are blocked and the specific surface area is reduced, thereby decreasing the adsorption characteristics.

In granulating the composition as described above, if the size is less than 0.2 mm, the gas flow resistance is increased after filling the fixed bed adsorption reactor, and the energy loss is large. have.

In the second process, alkaline earth metal salt and active metal were added to the granulated composition, and the mixture was left to stand for 1 to 24 hours while stirring at 100 to 300 rpm. Then, the precipitate was filtered off and 110 ± for 4 hours in a fluidized bed dryer. It is the process of manufacturing the granular composite molecular sieve of this invention by drying at 5 degreeC.

That is, the granulated composition is treated with an alkaline earth metal salt to convert an alkali metal silicate component contained as a binder into an alkaline earth metal silicate that is insoluble in water, and simultaneously converts 4A type zeolite into calcium A type (5A type) zeolite. It is a process for producing granular composite molecular sieves having excellent adsorption characteristics and selectivity for specific components by adding active metals such as copper, iron, zinc and aluminum to it, impregnating them on activated carbon, and ion-exchanging them with zeolite. .

At this time, calcium chloride or magnesium chloride is used as the alkaline earth metal salt, and preferably, an aqueous solution containing 10 to 35% by weight of calcium chloride and more preferably 15 to 30% by weight of calcium chloride is used. Alkaline earth metal salts are preferably used within the range of 10 to 35% by weight with respect to the total components constituting the granular composite molecular sieve of the present invention. If the amount is less than 10% by weight, the ion exchange of the zeolite is insufficient and the specific surface area is When the alkali metal silicate is reduced to alkali earth metal silicate, and when it exceeds 35% by weight, the excess salt concentration in the aqueous solution causes the sodium chloride component formed in the granular composite sieve to not diffuse into the aqueous phase, and the alkali metal silicate is alkali. The conversion to earth metal silicates is reduced.

In addition, the total supported amount of the active metal in the particulate composite molecular sieve of the present invention is most suitably about 2 to 30% by weight, more preferably about 5 to 20% by weight based on the total content. If the supported amount of the active metal is less than 2% by weight, the increase in adsorption amount is slight. If the supported amount is more than 30% by weight, the activated metal and the pore of the zeolite are blocked by the active metal, so there is a risk of adverse effect. Examples of the metal salt solution containing the active metal include an aqueous solution of zinc sulfate (ZnSO ₄ · 6H ₂ O), ferrous sulfate (FeSO ₄ · 7H ₂ O), aluminum sulfate (Al ₂ (SO ₄ ) ₃ · 13H ₂ O), and the like. It can be used, the active metal salt of the present invention is not limited to the sulfate and may be used as long as it is water-soluble.

As the granulation apparatus other than the flow share mixer used in the present invention, any one of a disc granulator, an injection molding granulator, a fluidized bed granulator, and a crushing granulator can be used.

The granular composite molecular sieve of the present invention produced by such a manufacturing process is based on solids 10 to 70% by weight zeolite, 10 to 70% by weight activated carbon, 10 to 35% by weight alkaline earth metal silicate and copper, zinc, iron and aluminum It contains 2 to 30% by weight of one or more active metals selected from. If the content of each of these components is outside the above range, it may be difficult to share lipophilic and hydrophilic adsorption characteristics, or to obtain a granular composite molecular sieve having a desired wear resistance, and the micropores inside the adsorbent may be blocked, resulting in poor adsorption characteristics. It is not preferable because there is a problem of deterioration.

For example, when the particulate composite molecular sieve of the present invention containing zinc sulfate as an active metal salt is used as a deodorant, chemical reactions for harmful gas components and malodorous components can be represented by the following reaction formulas 1 to 4.

Ammonia (NH ₃ ):

(1) ZnSO ₄ (aq) ↔ Zn ²⁺ + SO ₄ ^2-

Zn ²⁺ + 4NH ₃ ↔ Zn (NH ₃ ) ₄ ²⁺

_{(2) NH 3 + H 2} O ↔ NH 4 OH ↔ NH 4 + + OH -

2NH ₄ ⁺ + SO ₄ ^2- → (NH ₄ ) ₂ SO ₄

According to Scheme 1, one mole of zinc sulfate may react with 6 moles of ammonia or ammonium ion. In addition, it can be seen that when a small amount of water molecules are present in the reaction gas, ammonium ions are formed to increase ammonia to be removed.

Amines (RNH ₂ ; R is an alkyl group):

RNH ₂ + 1/2 H ₂ SO ₄ → RNH ₂ 1 / 2H ₂ SO ₄

Hydrogen sulfide (H ₂ S):

_{H 2 S + H 2 O ↔} H + + SH - + H 2 O

_{^{SH - + H 2 O ↔ H}} + + S 2- + H 2 O

Zn²⁺+ S^2-↔ ZnS

Fatty acid (ROOH; R is alkyl group):

RCOOH → RCOO ^{- +} H +

^{Zn 2+ + 2RCOO - → (RCOO} ) 2 Zn

As shown in the above Reaction Schemes 1 to 4, it can be seen that the granular composite molecular sieve on which zinc sulfate is supported is removed by reacting variously with the gas causing odor, and the granular composite molecular sieve on which other active metal salts are supported. In a similar principle, the reaction is carried out with ammonia, amines and hydrogen sulfide.

Such granular composite molecular sieve of the present invention has a specific surface area of 500 m 2 / g or more, ammonia adsorption capacity of 50 mg / g or more, hydrogen sulfide adsorption capacity of 50 mg / g or more, methyl mercaptan adsorption capacity of 60 mg / g or more The iodine adsorption power is 320 mg / g or more, the methylene blue decolorizing power is 65 mg / g or more, and the wear resistance is 99.5% or more.

Although this invention is demonstrated in detail based on an Example, this invention is not limited to an Example.

Example 1

Zeolite 4A powder (5.6 wt% water content, 13 kg) and activated carbon powder (6.2 wt% water content, 6.5 kg) were placed in a 130 liter flow share mixer (Rödige, Germany) and the spindle speed was 200 rpm and the microwave speed was 3600 rpm. After mixing the powder for 6 minutes under the conditions, the solution prepared by mixing sodium silicate aqueous solution (KS standard, water glass No. 3, 12.5 kg) and water (2.5 kg) was kneaded while injecting through a nozzle for 8 minutes and granulated for 15 minutes. To obtain a granular composite molecular sieve having an average particle diameter of 1.2 mm.

Calcium chloride (6.2 kg) was added to water (16.0 kg) and dissolved in the aqueous solution prepared by adding the above granular composite molecular sieve. The mixture was treated at 75 ° C. for 1 hour and then placed in a 60 mesh sieve to discharge the remaining liquid at 70 ° C. Water (15.0 kg) was added twice, washed with water and dried in a fluid bed drier at 90 ° C. to obtain a multifunctional granular composite molecular sieve (4.3 wt% of water content, 24.1 kg). An aqueous solution prepared by dissolving ferrous sulfate (FeSO ₄ · 7H ₂ O, 2.41 kg) in water (24 kg) was added to this granular composite sieve, and the mixture was slowly stirred, treated at 50 ° C. for 24 hours, and then discharged. Water (5 kg) was added twice, washed and dried in a fluid bed drier at 120 ° C. for 3 hours to obtain a granular composite molecular sieve for deodorant loaded with ferrous sulfate.

Example 2

To a solution prepared by adding zinc sulfate (ZnSO ₄ · 6H ₂ O, 2.34 kg) to water (24 kg) and dissolving was added a pretreatment sample treated with calcium chloride in Example 1 and treated in the same manner as in Example 1. A particulate composite molecular sieve for deodorant supported on zinc sulfate was obtained.

Example 3

To the aqueous solution prepared by adding aluminum sulfate (Al ₂ (SO ₄ ) ₃ .13H ₂ O, 2.81 kg) to water (24 kg) and dissolving was added the pretreated sample treated with calcium chloride in Example 1 and The same procedure was followed to obtain a granular composite molecular sieve for deodorant supported on aluminum sulfate.

Example 4

To the aqueous solution prepared by adding and dissolving copper sulfate (1.38 kg) to water (24 kg), a pretreatment sample treated with calcium chloride in Example 1 was added and treated in the same manner as in Example 1, where the granular composite for deodorant carrying copper sulfate was supported. Molecular sieves were obtained.

Experimental Example

For each of the granular molecular sieves prepared in Examples 1 to 4 and Comparative Examples 1 and 2, the specific surface area and the adsorption amount were measured by the following method, and the results are shown in Table 1 below.

Specific surface area measurement

After degassing the sample at about 350 ° C. for a sufficient time, the specific surface area was calculated by applying the BET equation to obtain a nitrogen adsorption isotherm under liquid nitrogen temperature.

Adsorption amount measurement

(1) Ammonia adsorption amount measurement

A gas equipped with a thermal conductivity detector was passed through the gas concentration at the outlet while a sample (1.0 g) was mounted on an adsorption column and a mixed gas prepared to be diluted to 99.95% ammonia in helium to 3.25% by weight was passed at a flow rate of 19.7 kW / min. Analyzed by chromatograph. Adsorption amount was calculated according to the following equation 1 with the point where the concentration corresponding to 2% of the inlet concentration is detected as the breaking point.

(2) hydrogen sulfide adsorption

A sample equipped with a sample (1.0 g) in an adsorption column and a mixed gas prepared by diluting 99.5% hydrogen sulfide in helium to 3.50% by weight at a flow rate of 19.7 kW / min while passing the gas concentration at the outlet through a thermal conductivity detector Analyzed by chromatograph. Adsorption amount was calculated according to Equation 1 using the point where the concentration corresponding to 2% of the inlet concentration is detected as the breaking point.

(3) Adsorption amount measurement of methyl mercaptan

A thermal conductivity detector was attached to the outlet gas concentration while passing a mixed gas prepared by mounting a sample (1.0 g) to an adsorption column and diluting 99.9% of methyl mercaptan to 2.62% by weight in helium at a flow rate of 19.7 kW / min. Analyzed by gas chromatography.

Adsorption amount was calculated according to Equation 1 using the point where the concentration corresponding to 2% of the inlet concentration is detected as the breaking point.

division Specific surface area (m ² / g) Adsorption amount (mg / g) ammonia Hydrogen sulfide Methyl mercaptan Example 1 570 72.7 60.4 65.8 Example 2 565 54.4 52.3 62.5 Example 3 560 98.0 100.9 70.4 Example 4 530 110.4 123.8 107.9 Comparative Example 1 ^a) 1130 3.0 39.2 165 Comparative Example 2 ^b) 515 19.3 3.0 24.3 a) Granular activated carbon (SGF-100, Samchully) b) Granular zeolite 5A (Molecular Sieve 5A, Aldrich)

The granular composite molecular sieve of the present invention is excellent in adsorption to water, organic solvents and toxic gases (ammonia, hydrogen sulfide, methyl mercaptan) due to the development of micropores, and separation of materials using water and sewage treatment and molecular sieve properties. It can be used for the deodorant, freshness retainer and air purifying deodorant filter for refrigerator and the like.

Claims (6)

In the granular composite sieve for deodorant, 10 to 70% by weight of zeolite, 10 to 70% by weight of activated carbon, 10 to 35% by weight of alkaline earth metal silicate and 2 to 30% by weight of one or more active metals selected from copper, zinc, iron and aluminum A granular composite molecular sieve for deodorant, wherein% is granulated. The granular composite sieve has a specific surface area of 500 m 2 / g or more, ammonia adsorption capacity of 50 mg / g or more, hydrogen sulfide adsorption capacity of 50 mg / g or more, and methyl mercaptan adsorption capacity of 60 mg / g or more. Granular composite molecular sieve for deodorant. In the manufacturing method of granular composite molecular sieve for deodorant, Granulating by injecting and kneading an aqueous alkali metal silicate solution into a mixture of zeolite and activated carbon; And And adding an aqueous alkaline earth metal salt solution to the granulated composition, and then carrying one or more active metals selected from copper, zinc, iron, and aluminum. According to claim 3, wherein the alkali metal silicate aqueous solution has a molar ratio of SiO ₂ / Na ₂ O of 2.2 to 3.8 and a solid content of 15 to 38% by weight, based on the solid content of the total component constituting the granular composite molecular sieve 10 to 10 A method for producing a granular composite molecular sieve for deodorant, characterized in that used within the range of 35% by weight. The method of claim 3, wherein the alkaline earth metal salt aqueous solution is an aqueous solution containing 10 to 35 wt% of calcium chloride. The method of claim 3, wherein the active metal is added in the form of sulfate.