JP2010269312A - Zeolite bead molding, and adsorption and removal method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide zeolite formed beads each concurrently having both high physical strength and excellent water adsorption performance, also to provide a production process by which such zeolite formed beads can easily be produced, and further to provide an adsorption/removal process for adsorbing and removing a specific component(s) such as moisture or water in a gas or liquid, by using the zeolite formed beads. <P>SOLUTION: Each of the zeolite formed beads consists of zeolite, kaolin type clay and an inorganic dispersant. The production process of the zeolite formed beads comprises: dispersing powdery zeolite, kaolin type clay and an inorganic dispersant into water to obtain an aqueous dispersion; subjecting the aqueous dispersion to mixing, kneading, forming and drying, to obtain dry beads; and heating and activating the beads. In this adsorption/removal process, the zeolite formed beads are used. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a zeolite bead molded article for drying a CFC refrigerant, and a method for adsorbing and removing water in a CFC refrigerant using the zeolite bead molded article. More specifically, it is widely used industrially for dry dehydration or adsorptive separation, and is useful for removing and removing water in Freon refrigerant by adsorbing and removing it. The present invention relates to a method for adsorbing and removing water using water.

  Usually, a zeolite compact is granulated and formed into a shape suitable for the purpose, such as beads and pellets, by adding a clay binder and a thickener or dispersant as a molding aid to the zeolite powder.

  In adsorbents produced using zeolite crystals and a non-adsorbing component clay-based binder, the key point is how to reduce the binder component in order to exhibit excellent adsorption performance. However, depending on the application of the adsorbent, the required physical properties and characteristics may vary. In particular, in the case of a desiccant application for the purpose of removing moisture, it is used under severe conditions such as vibration and heat regeneration. Therefore, there has been a problem that the performance of the agent becomes insufficient in terms of crushing and cracking due to expansion and contraction of the zeolite lattice in the molded body, peeling due to rubbing of the agent, and powdering.

  In order to improve the physical strength of the molded product, attempts have been made to increase the amount of the binder, and the moisture adsorption amount decreases in proportion to the increase in the amount of the binder. As a result, the binder becomes unsatisfactory and the binder is dispersed non-uniformly, which may result in a molded product having large variations in strength properties and moisture adsorption.

  In general, agents for dry dehydration applications require adsorption capacity rather than adsorption rate, so there is little need for excessively large pore volume, and therefore a smaller amount of binder, a denser and relatively low porosity. What is necessary is just to give a physical strength to a low molded object.

  The type of zeolite used for the drying dehydrating agent is determined by the molecular diameter of the substance to be dried, and A-type zeolite or faujasite-type zeolite is often used industrially. Therefore, 3A-type zeolite having an effective pore diameter of 3 angstroms is effective for adsorbing only water molecules having a molecular diameter of 2.8 angstroms. However, when higher adsorption capacity is required, Jasite-type zeolites are used, and these are selected as an indicator that they do not adsorb the material to be dried.

  Hereinafter, 3A type zeolite will be described as an example.

  The 3A-type zeolite compact is produced as follows. First, synthetic sodium A-type zeolite powder is exchanged in an aqueous potassium chloride solution, and 35% or more of sodium ions in the zeolite are exchanged with potassium ions to obtain 3A-type zeolite powder having an effective pore diameter of 3 angstroms. Next, after washing and filtration, a thickening agent or a dispersing agent is added to the powder as a clay binder and a molding aid, and the powder is molded into a shape suitable for the purpose by a granulation molding method such as rolling or extrusion. . The problem with the 3A-type zeolite molded body produced by such a method is how to uniformly disperse the clay component as a binder with a small addition amount to maintain strength and moisture adsorption performance.

  The present invention overcomes the conventional problems in such a zeolite molded product, and particularly requires 3A-type zeolite, 4A-type zeolite, etc. having strong physical strength and excellent moisture adsorption performance, which are required for dry dehydrating agents. It is also an object of the present invention to provide a molded body in which the zeolite is molded into beads and a method for adsorbing and removing water in the chlorofluorocarbon refrigerant using the zeolite bead molded body.

  As a result of intensive studies to solve the above problems, the present inventors added a condensed phosphate dissolved in water to a zeolite and a clay binder having a primary particle system of 1 μm or less. After kneading and kneading so that the density becomes 0.8 to 1.0 kg / liter, it is molded into beads by the rolling granulation method, then granulated, dried, and then activated to have a high physical strength. In addition, the inventors have found that a zeolite bead molded body excellent in moisture adsorption performance can be easily obtained. Further, by bringing such a zeolite bead compact into contact with a refrigerant such as 1,1,1,2-tetrafluoroethane, the refrigerant itself is hardly decomposed and water contained therein can be efficiently removed. The inventors have found that it can be adsorbed, and finally completed the present invention.

  Hereinafter, the present invention will be described in detail.

  As described above, A-type zeolite is preferably used from the viewpoint of the molecular diameter of the substance to be dried, as the zeolite used for the zeolite bead molded product for drying the refrigerant of the present invention.

  For example, 3A zeolite for ethylene plants, dry dehydration of chlorofluorocarbon refrigerants, 3A or 4A zeolite for removal of water in organic solvents, and forgers for cryogenic separation pretreatment or multi-layer glass. Site-type zeolite is generally used. Conventionally, 3A-type zeolite has been used for CFC refrigerants such as car air-conditioner refrigerant 1,1,1,2-tetrafluoroethane (hereinafter referred to as “HFC-134a”) in consideration of CFC adsorption decomposition. However, the molecular size of HFC-134a is as large as 4.7 × 5.1 × 5.6 Å, and even 4A zeolite having an effective pore size of 4 Å is basically not adsorbed. Therefore, it is considered that the solid acid characteristic or impurity metal cation derived from the clay binder used when adjusting the shape of some shaped body affects. In general, clay minerals represented by acid clay, bentonite, sepiolite, kaolin and the like have solid acid properties, which is considered to cause chlorofluorocarbon decomposition.

  Here, the zeolite bead compact of the present invention will be described by taking a 3A-type zeolite bead compact as an example. Synthetic sodium A-type zeolite powder in potassium chloride aqueous solution and 35% or more of sodium ions in the zeolite 3A-type zeolite powder having an effective pore diameter of 3 angstroms is used as a raw material. The zeolite bead molded body of the present invention is a molded body composed of such a zeolite, a kaolin type clay binder and an inorganic dispersant, and the pressure resistance of the average particle size of the molded body is 8 kgf or more. In addition, the moisture adsorption amount is 20% by weight or more.

  The shape of the zeolite bead molded body of the present invention may be a bead shape, and is not limited in any way, such as a spherical shape or an elliptical shape. Examples of the rolling granulation method include a plate type, a pan type, or an example using a stirring granulator equipped with stirring blades. As a method for producing the zeolite bead compact of the present invention, a blade stirring granulator is used. The method using is preferable. Regarding the bead diameter, any size may be used depending on the purpose of use. In consideration of the fact that the strength of the compact is proportional to the bead diameter, ease of molding, or operability, it is usually an agent for dry dehydration. Then, a molded body having a diameter of about 1.5 to 3.0 mm is preferably used.

  The kaolin-type clay used in the zeolite bead molded body of the present invention is present between the zeolite particles in the molded body as a binder, and in particular to increase the strength of the molded body, the molded body density is high. In order to reduce the ratio of voids present therein, that is, the void ratio, those having a primary particle diameter of 1 μm or less are preferred, and examples thereof include Georgia kaolin clay. These may be used alone or in combination of two or more.

  Furthermore, as the inorganic dispersant, those having high solubility in water and an aqueous solution exhibiting alkalinity are preferably used. Examples of such inorganic dispersants include condensed phosphates, and also sodium pyrophosphate, sodium tripolyphosphate, potassium pyrophosphate, sodium hexametaphosphate, potassium hexametaphosphate, and particularly sodium pyrophosphate and sodium tripolyphosphate. Potassium pyrophosphate is preferably used. These may be used alone or in a mixture of two or more.

  In the present invention, the dispersant is an inorganic condensed phosphate, one of which is the viscosity of the dispersant. For example, lignin sulfonate, which is an organic dispersant described in Japanese Patent Publication No. 39-21821, has many high molecular weight molecular weights of 10,000 or more and is molded because of its high viscosity. In the agitation rolling granulation method in which granulation molding is performed by utilizing the weight of the agent and centrifugal force, a partial mamaco state is likely to be formed, and granulation molding becomes difficult. Further, the molded bead-shaped molded bodies adhere to each other, and the shape becomes distorted, and the adhesion to the molding apparatus becomes severe, which is not preferable. Furthermore, in the process of final firing activation of the compact, not only does it impose a thermal shock on the zeolite due to sudden heat generation due to combustion, but also impairs the adsorption performance, and by forming pores, the compactness of the compact decreases. Strength properties will be impaired. On the other hand, inorganic dispersants are excellent in granulation properties because they are not high in viscosity, and the compactness of the molded products obtained because they remain between the zeolite particles in the molded products even after the firing activation treatment. Also excellent.

In the zeolite bead molded body of the present invention, the ratio of zeolite to kaolin-type clay and condensed phosphate which is an inorganic dispersant is 20 to 30 parts by weight of kaolin-type clay and 100% by weight of condensed phosphate. -10 parts by weight is a preferred range. Note that the condensed phosphate 4-10 parts by weight, an amount corresponding to about 2-5 parts by weight of phosphorus pentoxide _(P 2 _{O 5)} reference.

  Next, the manufacturing method of the zeolite bead compact of the present invention will be described.

  As a production method thereof, a condensed phosphate dissolved in water and dispersed in 20 to 30 parts by weight of kaolin-type clay with respect to 100 parts by weight of zeolite powder on an anhydrous basis and 100 parts by weight of zeolite powder is used. 4 to 10 parts by weight is added to the part, mixed and kneaded so that the bulk density is 0.8 to 1.0 kg / liter, and then formed into beads by a rolling granulation method such as blade stirring.

  The kaolin type clay, which is a clay binder added here, basically has a Si / Al content or a slightly different content of impurities such as alkali metal, alkaline earth metal, and transition metal depending on the type. It is a plate-like aluminosilicate having a molar ratio of 2.0, and in any clay, the granulation moldability and the physical properties of the molded body are the same, which is not a problem.

  The method for producing a zeolite bead molded body of the present invention includes a step of mixing and kneading zeolite powder and kaolin-type clay, and a condensed phosphate dissolved in water, a step of molding the kneaded product into beads, and drying the molded body. , The process of activating the firing is described below in order.

<Mixing and kneading process>
As the zeolite powder used in the method for producing a zeolite bead molded product of the present invention, A-type zeolite is preferably used, and for the purpose of selectively adsorbing and removing only moisture, A of 3A type and 4A type having a small effective pore diameter. Type zeolite is preferably used.

  For example, 3A-type zeolite powder is prepared by a known method, that is, sodium A-type zeolite powder synthesized from sodium aluminate and sodium silicate in an aqueous potassium chloride solution, and 35% or more of sodium ions in the zeolite are replaced with potassium ions. By exchanging, a 3A-type zeolite powder having an effective pore diameter of 3 Å can be obtained.

  Zeolite powder, kaolin-type clay, and inorganic dispersant dissolved with moisture necessary for granulation and molding are mixed and kneaded to be uniform after being put in a container, and the bulk density is 0.8 to 1.0 kg. Thoroughly kneaded to liter / liter. When the bulk density of the mixed and kneaded mixture is smaller than 0.8 kg / liter, the compaction effect is insufficient and air bubbles are present between the mixture particles, which may make it difficult to form a dense molded body.

  The amount of kaolin-type clay used is preferably in the range of 20 to 30 parts by weight with respect to 100 parts by weight of the zeolite powder in order to increase the physical strength of the molded body and maintain a high moisture equilibrium adsorption capacity. When the amount exceeds 30 parts by weight, the amount of zeolite is relatively decreased, and the amount of moisture adsorbed in the resulting molded product may decrease. When the amount is 20 parts by weight or less, the physical strength decreases, It may be difficult to withstand the purpose of use.

  Further, the amount of the condensed phosphate used in the method of the present invention is preferably 2 to 5 parts by weight dissolved in water based on phosphorus pentoxide with respect to 100 parts by weight of zeolite powder.

  The amount of water added to mix and knead the zeolite powder, kaolin-type clay binder, and condensed phosphate varies depending on the properties of the kaolin-type clay binder, etc., or the blending amount. Is preferably in the range of 40-60 parts by weight with respect to 100 parts by weight of zeolite powder. Therefore, when the condensed phosphate exceeds 10 parts by weight, it cannot be dissolved only with the added water, and is mixed in a slurry state, and the mixed kneaded material cannot be uniformly dispersed and a uniform molded body strength cannot be obtained. is there.

  Phosphorus pentoxide in the condensed phosphate is generally used as a drying / dehydrating agent and has moisture adsorption performance, but the accompanying sodium or potassium content is non-adsorbent, so 10 parts by weight. If the amount exceeds 50%, the amount of zeolite will be reduced, and the moisture equilibrium adsorption amount will decrease, which is not preferable. On the other hand, if it is less than 4 parts by weight, the effect of addition may be insufficient and the physical strength may not be satisfactory.

<Molding process>
In the mixing and kneading step, the mixture having been sufficiently kneaded and having a bulk density of 0.8 to 1.0 kg / liter is formed into a bead shape by a rolling granulation method such as blade stirring.

  Here, as the granulation method used in the method of the present invention, a rolling granulation method is preferably used, and a method using blade stirring is preferably used. This is because a strong shearing force is applied by stirring the blades compared to ordinary rolling granulation, and the clay binder dispersed in the condensed phosphate is more uniformly dispersed and adhered to the zeolite particles. This is because it can be formed into a dense molded body by closing the voids.

  The shape of the molded product is not limited as long as it has the characteristics of the present invention, and may be molded into a spherical shape, an elliptical shape, etc., for example, a bead molded body having a size of 7 to 10 mesh and can do. Further, when physical strength, particularly wear strength is required, it is desirable that the molded product is a bead molded product having a high sphericity, and the molded spherical product is subjected to a known method, for example, an arbitrary number of rotations using a Malmerizer molding machine. It is a generally performed method to smooth the surface of the molded body by adjusting the size under time conditions.

  In addition, the diameter of the molded and sized beads can be easily changed depending on the application, and if necessary, the size may be adjusted by classification with a sieve or the like.

<Activation process>
The molded body thus molded is dried, fired and activated, and the added kaolin type clay binder is sintered and moisture is desorbed. As drying and activation methods, known methods can be used. For example, a hot air dryer, an electric muffle furnace, a tubular furnace, a rotary furnace, etc. may be used.

  The firing / activation temperature is at a temperature of 600 ° C. or higher, which is the sintering temperature of kaolin-type clay, in order to stably maintain the physical strength of the obtained molded body and to completely desorb moisture in the molded body. It is preferable to carry out, and it is preferable to carry out at a temperature of 650 to 700 ° C.

  As a method for adsorbing and removing water in the chlorofluorocarbon refrigerant using the zeolite bead molded body of the present invention, the zeolite bead molded body of the present invention may be contacted with the target chlorofluorocarbon refrigerant and removed by a known method. Conditions such as amount and temperature can be appropriately determined. In particular, the zeolite bead molded body of the present invention can be used for a long time because of its excellent strength properties and moisture adsorption characteristics.

  As described above, the zeolite bead molded body obtained by the method of the present invention is widely used for dry dehydration or adsorption separation, for example, HFC-134a which is an chlorofluorocarbon refrigerant for automobiles, a mixed refrigerant containing the same, or an organic solvent. Alternatively, it is useful for applications in the field of adsorptive separation agents such as removal of moisture in the air and adsorption of carbon dioxide, which is an environmental problem of global warming.

  The reason why the physical strength of the zeolite bead molded body of the present invention is strong is that a plate-like kaolin type clay having a primary particle diameter of 1 μm or less is used as a binder, and a condensed phosphate for dispersing the agglomerated clay binder. In addition, the clay binder is further uniformly dispersed by applying a strong shearing force by molding with a blade stirring granulation method. That is, it is considered that the clay binder dispersed in the condensed phosphate is more uniformly dispersed and adhered to the zeolite particles, is present between the zeolite particles, closes the voids, and becomes a dense molded body.

  Further, it is considered that the water equilibrium adsorption performance can be maintained because it is formed with a relatively small amount of clay binder and that phosphorus pentoxide in the inorganic dispersant has a water adsorption ability.

  In addition, it is considered that the excellent point of drying of HFC-134a for car air conditioners is due to the inhibitory effect of inorganic dispersants added with the influence of solid acid characteristics or impurity metal cations in clay binders that are considered to decompose CFCs. It is done.

  However, such a guess does not bind the present invention.

  The present invention has the following effects.

  (1) The zeolite bead molded body of the present invention is a molded body having high adsorbent physical properties and high pressure resistance and moisture equilibrium adsorption amount.

  (2) According to the production method of the present invention, a zeolite bead molded body having excellent performance can be easily obtained.

  (3) The method of adsorbing and removing according to the present invention can efficiently adsorb water contained therein without decomposing the chlorofluorocarbon refrigerant.

  EXAMPLES Hereinafter, although this invention is demonstrated further in detail using an Example, this invention is not limited to these. In addition, each evaluation was implemented by the method shown below.

(1) Bulk density In accordance with the method using an apparent density measuring instrument of JIS-K-3362, the mixture after kneading and kneading is received in a polyethylene cup (W1) having a volume of Vml. After scraping with a spatula, the weight (W2) of the cup containing the mixture was read to the nearest 1 g, and the bulk density was calculated by the following formula.

  Bulk density (kg / liter) = (W2-W1) / V

(2) Pressure resistance After cooling the fired and activated bead molded body, it is quickly sieved with a three-stage sieve of 1.7 to 2.8 mm so as not to adsorb moisture, and the average size (2.0 to 2.4 mm) were measured one by one with a hardness meter (manufactured by Fujiwara Seisakusho, model: KHT-20). The measurement is based on a method of applying a weight to the molded body at a constant speed with an indenter having a diameter of 5 mm. The weight when the molded body is crushed is defined as the pressure strength (kgf), and the average value of the obtained values is measured It was set as the pressure resistance of the examples and comparative examples.

(3) Amount of moisture equilibrium adsorption The fired and activated bead compact was cooled and allowed to stand for 16 hours or more in a desiccator at a temperature of 25 ° C. and a relative humidity of 80% for complete hydration. Subsequently, it baked at 900 degreeC for 1 hour in the muffle furnace, and the water | moisture-content adsorption | suction adsorption amount adsorb | sucked to the molded object was measured.

(4) CFC decomposition test The CFC decomposition rate was evaluated by an accelerated test method called a shield tube test according to the American Refrigeration Association test method (ASRE method). The shield tube test is a sealed glass container with an internal volume of about 40 ml. About 2 g of HFC-134a and about 1 g of desiccant are sealed, heated to 175 ° C. and left for 30 days or more, and then the fluorine ions adsorbed by the agent Was measured to evaluate the decomposition of the refrigerant.

Example 1
Synthetic sodium A-type zeolite powder (manufactured by Tosoh Corporation, SiO ₂ / Al ₂ O ₃ = 2.0) was brought into contact with an aqueous potassium chloride solution to exchange 40% of sodium ions with potassium ions to prepare 3A-type zeolite powder. . 3 parts by weight of sodium pyrophosphate based on P ₂ O ₅ dissolved in 30 parts by weight of Georgia kaolin clay and 50 parts by weight of water with respect to 100 parts by weight of the 3A-type zeolite powder. The mixture was kneaded and kneaded sufficiently using a model manufactured by the company, model: MSG-05S). As a result of measuring the bulk density of the obtained kneaded product by the above method, it was 0.92 kg / liter.

  This kneaded product was stirred and granulated into a bead shape having a diameter of 1.7 mm to 2.8 mm with a blade stirring granulator Henschel mixer (Model: FM-75, manufactured by Mitsui Mining Co., Ltd.) The particles were sized using a NIPOWAL company, model: Q-1000), and then dried.

  Next, using a muffle furnace (manufactured by Advantech Co., Ltd., model: KM-600), the clay was sintered in a 650 ° C. atmosphere for 5 hours under air flow, and the clay was sintered and activated.

  The obtained 3A-type zeolite bead compact was measured for pressure resistance, moisture equilibrium adsorption amount, and CFC decomposability by the above methods. The results are shown in Table 1.

In Table 1, the amount of clay indicates parts by weight with respect to 100 parts by weight of zeolite, and the amount of dispersant indicates parts by weight of P ₂ O ₅ and Al ₂ O ₃ with respect to 100 parts by weight of zeolite. In the type of dispersant used, Na ₄ P ₂ O ₇ represents sodium pyrophosphate, Na ₅ P ₃ O ₁₀ represents sodium tripolyphosphate, and K ₄ P ₂ O 7 represents potassium pyrophosphate.

Examples 2-11
A 3A-type zeolite bead compact was prepared in the same manner as in Example 1 except for the amount of Georgia Kaolin clay shown in Table 1 and the type or amount of inorganic dispersant. The 3A-type zeolite powder used had a SiO ₂ / Al ₂ O ₃ molar ratio of 2.0 and a potassium ion exchange rate of 40%. The bulk density of the obtained kneaded product was measured by the above method. The range was from .88 to 0.99. After granulation molding, the pressure resistance, moisture equilibrium adsorption amount, and CFC decomposability of the obtained 3A-type zeolite bead compact were measured by the above methods. The results are shown in Table 1.

Example 12
P ₂ O dissolved in 30 parts by weight of Georgia kaolin clay and 50 parts by weight of water with respect to 100 parts by weight of synthetic sodium A-type zeolite powder (manufactured by Tosoh Corporation, SiO ₂ / Al ₂ O ₃ = 2.0) _{Based on 5} standards, 4 parts by weight of sodium tripolyphosphate was mixed and kneaded with a MixMuller kneader (manufactured by Shinto Kogyo Co., Ltd., model: MSG-05S), and kneaded sufficiently. As a result of measuring the bulk density of the obtained kneaded product by the above method, it was 0.94 kg / liter.

  This kneaded product was stirred and granulated into a bead shape having a diameter of 1.7 mm to 2.8 mm with a blade stirring granulator Henschel mixer (Model: FM-75, manufactured by Mitsui Mining Co., Ltd.) The particles were sized using a NIPOWAL company, model: Q-1000), and then dried.

  Next, using a muffle furnace (manufactured by Advantech Co., Ltd., model: KM-600), the clay was sintered in a 650 ° C. atmosphere for 5 hours under air flow, and the clay was sintered and activated.

  The pressure resistance, moisture equilibrium adsorption amount, and CFC decomposability of the obtained 4A-type zeolite bead compact were measured by the above methods. The results are shown in Table 2.

In Table 2, the amount of clay indicates parts by weight with respect to 100 parts by weight of zeolite, the amount of aluminum hydroxide indicates parts by weight of Al ₂ O ₃ with respect to 100 parts by weight of zeolite, and the amount of dispersant means 100 parts by weight of zeolite. Parts by weight of P ₂ O ₅ with respect to parts. Further, in the type of dispersing _agent, Na ₅ P _{3 O 10} sodium _{tripolyphosphate,} Na ₄ P 2 _{O 7} shows the sodium pyrophosphate.

Examples 13-16
A 4A-type zeolite bead molded body was prepared in the same manner as in Example 12 except for the addition amount of Georgia kaolin clay shown in Table 2 and the type or addition amount of the inorganic dispersant. The 4A-type zeolite powder used had a SiO ₂ / Al ₂ O ₃ molar ratio of 2.0, and the bulk density of the obtained kneaded product was measured by the above method. As a result, the range was 0.90 to 0.99. Met. After granulation molding, the pressure resistance, moisture equilibrium adsorption amount, and CFC decomposability of the obtained 4A-type zeolite bead compact were measured by the above methods. The results are shown in Table 2.

Comparative Examples 1-5
A 3A-type zeolite bead compact was prepared in the same manner as in Example 1 except that the amount of Georgia Kaolin clay shown in Table 3 and the inorganic dispersant were not used. The 3A-type zeolite powder used had a SiO ₂ / Al ₂ O ₃ molar ratio of 2.0 and a potassium ion exchange rate of 40%. The bulk density of the obtained kneaded product was measured by the above method. The range was from 83 to 0.95. After granulation molding, the pressure resistance, moisture equilibrium adsorption amount, and CFC decomposability of the obtained 3A-type zeolite bead compact were measured by the above methods. The results are shown in Table 3.

  In Table 3, the amount of clay indicates parts by weight with respect to 100 parts by weight of zeolite.

Comparative Examples 6-8
A 3A-type zeolite bead compact was prepared in the same manner as in Example 1 except for the type and amount of dispersant shown in Table 4. The 3A-type zeolite powder used had a SiO ₂ / Al ₂ O ₃ molar ratio of 2.0 and a potassium ion exchange rate of 40%, and 30 parts by weight of Georgia kaolin clay was added and mixed and kneaded. As a result of measuring the bulk density of the obtained kneaded product by the above method, it was in the range of 0.80 to 0.84 kg / liter. After granulation molding, the pressure resistance and water balance of the obtained 3A-type zeolite bead compact were measured by the above methods. The results are shown in Table 4.

  In Example 4, the amount of the dispersant represents the weight part of the dispersant with respect to 100 parts by weight of zeolite, and the sun extract in Table 4 represents sodium lignin sulfonate.

  Comparing the above examples and comparative examples, it can be seen that the pressure resistance strength of the 3A-type or 4A-type zeolite bead compact obtained from the examples is remarkably strong, and the moisture equilibrium adsorption amount is high. In particular, the effect of adding condensed phosphate when the same amount of clay binder is used for the zeolite powder is apparent. The effect was clear when compared with the case where the condensed phosphate was not added or when the organic dispersant sodium lignin sulfonate was added.

  In addition, in the result of carrying out the CFC decomposition test using the zeolite bead molded body obtained in the example, it can be seen that the CFC decomposition rate is very small compared to the result of the comparative example, and CFC is hardly decomposed. .

Claims (8)

  A zeolite bead molded article for drying Freon refrigerant, which is made of zeolite, kaolin-type clay and condensed phosphate, and has a compressive strength of 8.2 kgf or more. The zeolite bead molded body for drying a fluorocarbon refrigerant according to claim 1, wherein the pressure strength is 8.2 kgf or more and 9.5 kgf or less.   The fluorocarbon refrigerant according to claim 1 or 2, comprising zeolite, 20-30 parts by weight of kaolin clay and 4-10 parts by weight of condensed phosphate with respect to 100 parts by weight of the zeolite. Zeolite bead compact for drying.   The zeolite bead molded body for drying a CFC refrigerant according to any one of claims 1 to 3, wherein the zeolite is A-type zeolite.   The fluorocarbon according to any one of claims 1 to 4, wherein the condensed phosphate is one or more selected from the group consisting of sodium pyrophosphate, sodium tripolyphosphate and potassium pyrophosphate. Zeolite bead molded body for refrigerant drying.   The zeolite bead molded body for drying a CFC refrigerant according to any one of claims 1 to 5, wherein the CFC refrigerant is 1,1,1,2-tetrafluoroethane (HFC-134a).   A method for adsorbing and removing water from a chlorofluorocarbon refrigerant using the zeolitic bead molded body for drying the chlorofluorocarbon refrigerant according to any one of claims 1 to 6.   The method for adsorbing and removing water according to claim 7, wherein the chlorofluorocarbon refrigerant is 1,1,1,2-tetrafluoroethane (HFC-134a).