JP4886179B2 - Nitrogen-containing zeolite, production method thereof, adsorbent containing nitrogen-containing zeolite, heat utilization system, adsorption heat pump and cold storage heat system - Google Patents

Description

  The present invention relates to a zeolite containing nitrogen with a specific content (hereinafter referred to as nitrogen-containing zeolite), a production method thereof, an adsorbent containing nitrogen-containing zeolite, a heat utilization system, an adsorption heat pump, and a cold storage heat system.

  Zeolites are widely used as adsorbents, catalysts for acid reactions and oxidation reactions, separation materials, optical materials such as quantum dots and quantum wires, and host materials such as semiconductor fine particles, phosphors, and dyes used as magnetic materials. . Zeolite includes crystalline silicates, crystalline aluminophosphates, and the like according to the provisions of the International Zeolite Association (referred to herein as IZA).

  Zeolite is usually produced by hydrothermal synthesis using a zeolite raw material and a structure-directing agent (also referred to as an organic template), and then removing the organic template by a method such as calcination or extraction. In general, zeolite from which an organic template has been removed as much as possible is used as an industrially useful zeolite for a catalyst, an adsorbent, or the like. The reason for removing the organic template as much as possible is that the zeolite before removal of the organic template obtained by hydrothermal synthesis or the like (referred to as a zeolite precursor in this application) has the space in the pores occupied by the organic template. This is because the reaction substrate or the adsorbed substance cannot enter the pores and the function as a catalyst or an adsorbent is not exhibited. Therefore, industrially useful zeolite is usually in a form in which the organic template is removed from the zeolite precursor as much as possible.

  By the way, in Patent Document 1 below, when a part of the pore structure of zeolite is occupied by an organic template or a decomposition product of the organic template, since the adsorption of moisture in the atmosphere is prevented during storage or transportation, the catalytic activity Does not decrease, and the examples show examples where 8.20% by weight or more of carbon atoms remain. On the other hand, when using zeolite as a catalyst, it is taught that as an activation treatment, firing or combustion treatment is performed in an oxygen-containing atmosphere to completely remove the organic template and the like from the pore structure of the zeolite.

  In addition, as a method for producing iron aluminophosphate using iron as a hetero atom among zeolites, in Patent Document 2 below, when an organic template is removed from a zeolite precursor of iron aluminophosphate, A method is described in which a zeolite precursor is heated under nitrogen flow to decompose and remove the organic template (firing).

Non-Patent Document 1 below describes a silicoaluminophosphate having a GIS structure in which carbon atoms are 3.99 wt% to 6.09 wt% and nitrogen atoms are remaining 4.83 wt% to 6.09 wt%. (SAPO-43) _has, CO _2, H 2 O, are reported to exhibit a selective adsorbability, such as _{H 2} S. However, the zeolite is essentially unstable when the organic template is completely removed, and the crystal structure collapses as the organic template is removed, and the adsorption capacity is almost completely removed when the organic template is completely removed. Has been shown to lose. Further, in the zeolite, the adsorption capacity of the zeolite obtained while maintaining the structure by leaving the organic template was as low as 8% by weight when the adsorbed water was water.
US Pat. No. 6,395,674 US Pat. No. 4,554,143 (Example) RTYang et al., Langmuir, 2003, 19, 2193-2200

  As described above, conventional zeolites have a relatively large amount of organic template or a substance derived from the zeolite remaining in the zeolite, removed as much as possible, or stable when the organic template is completely removed. In the zeolite that cannot be present in the above, the organic template is removed to such an extent that the crystal structure is not completely destroyed.

  Therefore, the conventional zeolite has insufficient adsorption capacity when used as an adsorbent, or has insufficient durability when repeatedly used as an adsorbent when the adsorption capacity is sufficient.

  In contrast, even if the zeolite is stable with the organic template in the zeolite completely removed, the initial adsorption capacity or catalytic activity is high when the organic template in the pores is completely removed. However, it has been found that the powdering of the particles and the destruction of the crystal structure occur with use, and the adsorption performance may be lowered accordingly. On the other hand, if a part of the organic template remains in the pores of the zeolite above a certain content, it is effective to prevent the catalyst activity from being reduced by moisture in the atmosphere during storage. However, it has been found that the adsorption capacity and the like cannot be sufficiently obtained from the initial stage.

  The present invention has been made to solve the above-mentioned problems, and its object is to provide a zeolite with little performance deterioration in repeated use or long-time use, and a method for producing the same, particularly as an adsorbent. In this case, an object of the present invention is to provide a zeolite having a sufficiently large adsorption capacity, and which does not cause pulverization of zeolite particles, crystal structure destruction, and accompanying decrease in adsorption capacity due to repeated use, and a method for producing the zeolite. Another object of the present invention is to provide an adsorbent containing such zeolite, a heat utilization system using the adsorbent, an adsorption heat pump, and a cold storage heat system.

  As a result of intensive studies on the above problems, the present inventors have found that the zeolite is Me (where Me is at least one element selected from the elements of Groups 2A, 7A, 8, 1B and 2B of the periodic table). Aluminophosphate, which may contain the same, and controls the amount of organic template or material derived from the zeolite remaining in the zeolite, resulting in a nitrogen content and carbon content in the zeolite. It has been found that a zeolite whose amount is controlled to a specific amount solves the above-mentioned problems. Furthermore, the present inventors have found that an adsorbent using zeolite with adjusted nitrogen content and carbon content is excellent in durability. Furthermore, the present inventors are effective in using the adsorbent in a heat utilization system or a cold storage heat system, specifically, a cold storage heat system, an adsorption heat pump, a dehumidification or humidification humidity control air conditioner. It has been found that it can be effectively used as an adsorbent for general purpose.

  That is, the zeolite of the present invention that solves the above problems has a nitrogen content of 0.5 wt% or more and 12 wt% or less, a carbon content of 1 wt% or more and 8 wt% or less, and aluminum is partially Me. It is characterized by being an aluminophosphate which may be substituted.

  According to the present invention, the zeolite containing nitrogen and carbon in the above range has a large adsorption capacity when used, for example, as an adsorbent, resulting in the destruction of the crystal structure accompanying repeated use and the accompanying decrease in adsorption capacity. It has an excellent effect of not being.

  In the zeolite of the present invention, the weight ratio of carbon to nitrogen (C / N weight ratio) is preferably 0.8 or more and 6.5 or less, and the C / N weight ratio is 1.0 or more and 4.0. It is particularly preferred that

  In the zeolite of the present invention, it is preferable that each molar ratio of Me, Al, and P constituting the framework structure of the aluminophosphate that may contain Me satisfies the following formulas 1 to 3. More preferably, the molar ratio of Me satisfies the following formula 1 ′.

0 ≦ x ≦ 0.3… 1
(X represents the molar ratio of Me to the sum of Me, Al and P)
0.2 ≦ y ≦ 0.6 2
(Y represents the molar ratio of Al to the sum of Me, Al and P)
0.3 ≦ z ≦ 0.6 3
(Z represents the molar ratio of P to the sum of Me, Al and P)
0.001 ≦ x ≦ 0.3… 1 ′
(X represents the molar ratio of Me to the sum of Me, Al and P)

In the zeolite of the present invention, it is preferred framework density is 10T / nm ³ or more 17.4T / nm ³ or less. Further, the zeolite is preferably one whose structure is maintained in a state where the organic template is completely removed. The skeletal structure is preferably a structure selected from AEI, AFR, AFS, AFT, AFX, ATS, CHA, ERI, LEV, LTA and VFI represented by a code defined by IZA, and in particular, AEI, CHA and A structure selected from LEV is preferred. Me is preferably at least one element selected from Fe, Ni, Co, Mg and Zn, and particularly preferably Fe. The molar ratio of nitrogen to Me is preferably 0.2 or more and 3 or less. Moreover, it is preferable that the skeletal structure before calcination is maintained when the zeolite is calcined to have a carbon content and a nitrogen content of less than 0.3% by weight.

  Moreover, in the zeolite of the present invention, when the repeated durability test of the zeolite is performed according to the following, it is preferable that the crystal structure before the test is maintained. In the present application, the “repetitive durability test” is a test in which the operation of holding the zeolite in a vacuum vessel maintained at 90 ° C. and exposing it to a vacuum state and a saturated steam atmosphere at 90 ° C. for 90 seconds is repeated 500 times. . “Crystal structure is retained” means that the strongest peak intensity after repeated endurance test is repeated endurance when XRD measurement is performed with the same equipment, the same measurement conditions, the same sample holder and the same sample weight. It means 50% or more of the strongest peak intensity before the property test. The peak intensity is the peak height and is defined by subtracting the background count from the peak top count.

  A method for producing a zeolite according to the present invention that solves the above-mentioned problems is a method for producing the above-mentioned zeolite, and is obtained by hydrothermally synthesizing at least a metal element compound constituting the zeolite in the presence of a structure indicating material. The obtained zeolite precursor is calcined in an atmosphere having an oxygen concentration of 0.1 vol% or more and 20 vol% or less.

  In the invention of this production method, the temperature at which the zeolite precursor is calcined is preferably 300 ° C. or higher and 440 ° C. or lower. Further, the zeolite precursor is hydrothermally synthesized in the presence of two or more kinds of structure indicating materials, and the structure indicating materials are (1) an alicyclic heterocyclic compound containing nitrogen, (2) cycloalkyl. It is desirable to be selected from two or more groups consisting of an amine having a group and (3) an amine having an alkyl group. Also, the zeolite precursor is morpholine, cyclohexylamine, triethylamine, isopropylamine, N, N-diisopropylethylamine, N-methyl-n-butylamine, isobutylamine, hexamethyleneimine, N, N-diethylethanolamine and N, N -It is desirable to be synthesized in the presence of at least one nitrogen-containing organic compound selected from dimethylethanolamine as a structure indicating material.

  According to the inventions of these production methods, the zeolite of the present invention that exhibits the above effects can be produced stably.

  The adsorbent of the present invention that solves the above-described problems includes the above-described nitrogen-containing zeolite of the present invention.

In this adsorbent invention, (i) zeolite is an adsorbed material when the relative vapor pressure changes by 0.15 in the range of the relative vapor pressure of 0.01 to 0.5 on the adsorption isotherm measured at 25 ° C. It is preferable to have a relative vapor pressure region in which the change in the adsorption amount of 0.1 g / g or more. Further, the adsorbent of the present invention is (ii) a heat utilization system that uses adsorption heat generated by adsorption of the adsorbent on the adsorbent, and / or latent heat of vaporization that is generated when the adsorbent is evaporated from the adsorbent. preferably used in the heat utilization system, utilizing, (iii) the heat utilization system, the configuration for desorbing the adsorbed material was supplied to the adsorbent: (a) waste heat, (b-1 ) Configuration to supply the heat of adsorption generated when the adsorbed material is adsorbed to the adsorbent, and / or (b-2) generated when the adsorbed material evaporates from the adsorbent. that it is preferable as the structure for supplying a cooling medium circulating through the cooling refrigeration machine the evaporation latent heat, a cold storage heat system with. Further, the adsorbent of the present invention is (iv) an adsorbent used in the cold storage heat system, and the zeolite contained in the adsorbent is at an adsorption isotherm measured at 55 ° C. with a relative vapor pressure of 0. It is desirable to have a relative vapor pressure region where the adsorption amount change of the adsorbed material is 0.05 g / g or more when the relative vapor pressure is changed by 0.05 in the range of 0.02 to 0.1. In the present invention, it is preferable that (v) the heat utilization system is an adsorption heat pump.

  According to the inventions of these adsorbents, the zeolite constituting the adsorbent has suitable characteristics that the crystal structure is not broken and the adsorbing capacity is reduced due to repeated use. Has excellent durability. Therefore, this adsorbent can be preferably used in a heat utilization system, an adsorption heat pump, or a cold storage heat system.

  The present invention for solving the above-described problems comprises a heat utilization system, an adsorption heat pump, and a cold storage heat system using the adsorbent described above.

  According to this invention, since the adsorbent excellent in durability containing the zeolite of the present invention described above is used, the durability of the system is excellent.

  As described above, according to the zeolite of the present invention, since it contains the predetermined amount of nitrogen and carbon, especially when used as an adsorbent, the adsorption capacity is large and the particles are pulverized with repeated use, It has an excellent effect that the crystal structure is not destroyed and the adsorption capacity is not lowered.

  Moreover, the heat utilization system using the adsorbent containing the zeolite of the present invention has an effect that the durability of the system is excellent by using the adsorbent containing the zeolite of the present invention.

  Hereinafter, the nitrogen-containing zeolite of the present invention (in the present application, sometimes simply referred to as “zeolite”), a production method thereof, an adsorbent containing nitrogen-containing zeolite, a heat utilization system, an adsorption heat pump, and a cold storage heat system are sequentially described. To do.

(Nitrogen-containing zeolite)
The zeolite according to the present invention contains 0.5 wt% or more and 12 wt% or less of nitrogen, and contains 1 wt% or more and 8 wt% or less of carbon. For example, when used as an adsorbent, the zeolite is used repeatedly. There is a feature that it has an excellent effect that the accompanying crystal structure is not destroyed and the accompanying adsorption capacity is not reduced.

  The zeolite of the present invention exhibiting such characteristics has a structure belonging to crystalline silicates, crystalline aluminophosphates, etc. according to the classification of International Zeolite Association (International Zeolite Association: IZA), and will be described later. From the viewpoint of durability as an adsorbent and adsorption characteristics, aluminum in the aluminophosphate may be partially substituted with a heteroatom (in this application, represented by Me) (Me-) aluminophosphate. It is. Here, Me is at least one element selected from elements of Groups 2A, 7A, 8, 1B, and 2B of the periodic table. In the following, the aluminophosphate that may contain Me may be represented by “(Me−) aluminophosphate”.

  In the (Me-) aluminophosphate, it is preferable that each molar ratio of Me, Al and P constituting the skeleton structure satisfies the following formulas 1 to 3. At this time, it is more preferable that the molar ratio of Me satisfies the following formula 1 '.

0 ≦ x ≦ 0.3… 1
(X represents the molar ratio of Me to the sum of Me, Al and P)
0.2 ≦ y ≦ 0.6 2
(Y represents the molar ratio of Al to the sum of Me, Al and P)
0.3 ≦ z ≦ 0.6 3
(Z represents the molar ratio of P to the sum of Me, Al and P)
0.001 ≦ x ≦ 0.3… 1 ′
(X represents the molar ratio of Me to the sum of Me, Al and P)

  When x indicating the molar ratio of Me is larger than the upper limit of the above range, impurities tend to be mixed. On the other hand, even if x is 0, the effect of the present invention is obtained. However, when the lower limit is close to 0, the amount of adsorption in the region where the pressure of the adsorbent is low or the synthesis is reduced when used as an adsorbent. Therefore, the lower limit of x is preferably 0.001 as shown by the above formula 1 ′. Further, when y indicating the molar ratio of Al and z indicating the molar ratio of P are out of the above ranges, the synthesis becomes difficult.

  About each molar ratio of Me, Al, and P, it is more preferable to satisfy the following formulas 4 to 6, and the synthesis of (Me-) aluminophosphate is further facilitated, contamination of impurities is suppressed, and further desired It becomes easy to obtain the adsorption characteristics.

0.01 ≦ x ≦ 0.3… 4
(X represents the molar ratio of Me to the sum of Me, Al and P)
0.3 ≦ y ≦ 0.5 5
(Y represents the molar ratio of Al to the sum of Me, Al and P)
0.4 ≦ z ≦ 0.5 ... 6
(Z represents the molar ratio of P to the sum of Me, Al and P)

  Me may be at least one element selected from the elements of Group 2A, Group 7A, Group 8, Group 1B, and Group 2B of the periodic table, and may be included in two or more. Preferable Me is an element (Mg) belonging to the third period of the periodic table and an element (Ca, Mn, Fe, Co, Ni, Cu, Zn) belonging to the fourth period. Among these, those having an ionic radius of 0.3 to 0.8 in the divalent state (Mn, Fe, Co, Ni, Cu, Zn, Mg) are preferable, and more preferably, they are divalent. In addition, in the four-coordinate state, the ion radius is 0.4 to 0.7 (Fe, Co, Cu, Zn, Mg). Among these, from the viewpoint of easy synthesis and adsorption characteristics, one or two elements selected from Fe, Co, Mg, and Zn are preferable, and Fe is particularly preferable. 1Å is a unit converted to 10 nm.

  The (Me-) aluminophosphate having the above-described configuration may include a component having a cation species capable of ion exchange with other cations, in addition to the component constituting the skeleton structure. Examples of such cationic species include protons, alkaline elements such as Li, Na, and K, alkaline earth elements such as Mg and Ca, rare earth elements such as La and Ce, and transition metal elements such as Fe, Co, and Ni. . Among these, protons, alkali elements, and alkaline earth elements are preferable.

Zeolites of the present invention, the framework density, it is usually preferable 10T / nm ³ or more 17.4T / nm ³ or less. If the framework density is less than the lower limit of the above range, the structure of the zeolite tends to be unstable, whereas if the framework density exceeds the upper limit of the above range, the amount of adsorption tends to be small. Such framework density, more preferably 12T / nm ³ or more, more preferably 13T / nm ³ or more. On the other hand, the framework density is more preferably 16T / nm ³ or less, and more preferably 15T / nm ³ or less. Here, T is an atom other than oxygen atoms constituting the skeleton of the zeolite, and T / nm ³ is a unit indicating the number of T atoms (framework density) present per nm ³ .

  The framework structure of the zeolite according to the present invention is a code determined by IZA, and is a structure selected from AEI, AFR, AFS, AFT, AFX, ATS, CHA, ERI, LEV, LTA and VFI. Among these, from the viewpoint of adsorption characteristics and structural stability, a structure selected from AEI, CHA, and LEV is preferable, and CHA is particularly preferable.

  The (Me-) aluminophosphate, which is a zeolite according to the present invention, retains the skeletal structure before calcination when the carbon content and the nitrogen content are both less than 0.3% by weight. Are preferred. Here, when both the carbon content and the nitrogen content are less than 0.3% by weight, the skeleton structure before firing is maintained. This means that the (Me-) aluminophosphate-specific skeleton structure is maintained. When the following (1) or (2) is satisfied, the inherent skeleton structure is considered to be retained, and preferably both the following (1) and (2) are satisfied It is. Hereinafter, (1) and (2) will be described.

  (1) An ideal water vapor adsorption amount assuming that an ideal skeleton structure is maintained is Qi, and after firing until both the carbon content and the nitrogen content are less than 0.3% by weight. When the water vapor adsorption amount (25 ° C., relative vapor pressure 0.5) is Qc, Qc / Qi is 0.4 or more. However, Qi is determined according to the following (1-1) or (1-2). Note that the structural skeleton here refers to a code defined by IZA, and even if the elements constituting the skeleton are different, those described with the same code are regarded as the same skeleton structure.

  (1-1) When structural analysis of the framework structure of zeolite in a hydrated state has been made; the ratio of the contained water to the formula weight of the crystal in the hydrated state is defined as Qi.

  (1-2) If the skeletal structure of the hydrated zeolite has not been analyzed; DWBreck, "ZEOLITE MOLECULAR SIEVES: STRCTURE, CHEMISTRY, AND USE", A WILEY-INTERSCIENCE PUBLICATION, 1974- In page 50 and Table 2.4, the Void Fraction of the zeolite having the corresponding structure is defined as Qi.

  (2) In the powder X-ray diffraction pattern, among the peaks measured in the state before firing, at least one of the three peaks having a large intensity ratio derived from the corresponding crystal structure is carbon content and nitrogen content by firing. Even after setting both of these to less than 0.3% by weight, it has a peak height of 50% or more before firing. In addition, the measurement of peak intensity shall be performed with the same sample weight using the same sample holder.

  The peak intensity is measured by the following method (A) or (B) from the viewpoint of measurement accuracy.

  (A) When an internal standard is not used: Measure under the same conditions and compare the absolute values of the peak intensities of the samples to be measured. When the same sample is measured before and after measuring the peak intensity of the sample to be measured, the change in absolute value of the peak intensity is preferably 10% or less.

  (B) When using an internal standard substance: Mix the internal standard substance at a certain weight ratio, measure the peak intensity of the sample to be measured and the peak intensity of the internal standard substance (peak intensity ratio), Compare peak intensity ratios.

  More specifically, for example, the following methods can be mentioned.

  (A) Using the same apparatus, the sample is pulverized well manually with a mortar or the like, the measurement sample amounts are the same, and the measurement is performed under the same conditions. At this time, it is desirable that the measurements of the samples for comparing the intensities are as close as possible in time. In addition, in order to keep the state of the X-ray source as constant as possible, a well-known consideration shall be given to those who perform general XRD measurements. In addition, the same sample is measured before and after the comparative measurement to confirm that the change in diffraction intensity is 10% or less.

  (B) If the same device cannot be used, or if the X-ray source state may change significantly even in the same device, add the same internal standard substance to the measurement sample at a constant weight ratio, and mortar After mixing well, etc., XRD measurement is performed. Comparison of peak intensities between samples is performed by a ratio of the intensity of a diffraction peak derived from an internal standard substance and the diffraction peak intensity derived from zeolite. The internal standard substance is selected with knowledge known to those skilled in the art, such as not having a diffraction peak at the diffraction peak position derived from the zeolite whose intensity is to be compared.

  In addition, the indicator that both the carbon content and the nitrogen content are less than 0.3% by weight after firing is an indicator that indicates a state in which the organic template used for the production of (Me-) aluminophosphate is removed. It is a value determined by the detection limit.

  Moreover, as a calcination condition in the case where both the carbon content and the nitrogen content are less than 0.3% by weight by calcination, for example, it can be 450 ° C. or more and 2 hours in an oxygen-containing atmosphere.

  In the case of (Me-) aluminophosphate that does not retain the pre-firing skeletal structure after firing, due to the skeletal structure, for example, when repeatedly used as an adsorbent, the crystal structure tends to break down and the adsorption characteristics are reduced. Tend to.

  As described above, the zeolite according to the present invention contains 0.5% by weight to 12% by weight of nitrogen and 1% by weight to 8% by weight of carbon. Zeolite containing nitrogen and carbon in this range has an excellent effect that, for example, when used as an adsorbent, the crystal structure is not broken and the adsorbing capacity is lowered due to repeated use. In particular, the crystal structure is hardly broken and the durability is improved. Therefore, it can be preferably applied to various practical uses. Examples of practical applications include a heat utilization system, an adsorption heat pump, and a cold storage heat system described later.

  When the nitrogen content and the carbon content exceed the upper limits of the above ranges, the adsorption amount decreases particularly when used as an adsorbent, and the performance as an adsorbent becomes insufficient. On the other hand, when the nitrogen content and the carbon content are less than the lower limit of the above range, there may be a problem in durability due to repeated use, particularly when used as an adsorbent.

  The nitrogen content is preferably 0.5% by weight or more, more preferably 0.8% by weight or more, and particularly preferably 1.0% by weight or more. Further, the nitrogen content is preferably 5% by weight or less, and particularly preferably 3% by weight or less. On the other hand, the carbon content is preferably 1.5% by weight or more, and more preferably 2% by weight or more. Further, the carbon content is preferably 6% by weight or less, and particularly preferably 5% by weight or less.

  The reason why the durability of zeolite containing nitrogen and carbon in this range is improved is not clear enough, but the change in crystal structure, change in lattice constant, and change in bonding state during adsorption / desorption are all small. It is believed that there is.

  In the zeolite of the present invention, the weight ratio of carbon to nitrogen (C / N weight ratio) is preferably 0.8 or more and 6.5 or less, 1.0 or more, 4 or less, particularly 3.5 or less. More preferably. If this C / N weight ratio is within the above range, the durability tends to be high and the adsorption capacity tends to be large. On the other hand, when the C / N weight ratio is less than 0.8, the durability tends to decrease.

  When Me is contained in the zeolite, the molar ratio of nitrogen to Me (N / Me ratio) is preferably 0.1 or more and 10 or less. Especially, it is preferable that N / Me ratio is 0.2 or more, and it is especially preferable that it is 0.5 or more. On the other hand, the N / Me ratio is preferably 5 or less, and particularly preferably 2 or less. When the N / Me ratio exceeds the upper limit of the above range, the adsorption amount tends to decrease, and when the N / Me ratio is less than the lower limit of the above range, the durability tends to decrease.

  In the zeolite according to the present invention, the proportion of the portion where the adsorbed substance (sometimes referred to as an adsorbate) can enter and leave the pore structure (the pore utilization rate defined by the following formula 7) is 0. It is preferable that it is .6 or more and 0.99 or less. The pore utilization rate is more preferably 0.7 or more, and particularly preferably 0.8 or more. On the other hand, the pore utilization rate is more preferably 0.95 or less, and particularly preferably 0.93 or less.

Pore utilization factor = Q1 / Qs ... 7
Here, Qs is the water vapor adsorption amount when the structure indicating material is completely removed, and Q1 is the water vapor adsorption amount of the zeolite according to the present invention. However, this water vapor adsorption amount represents the water vapor adsorption capacity per unit weight at a relative vapor pressure of 0.5 and room temperature (25 ° C.).

  When the zeolite of the present invention is subjected to a repeated durability test according to the following, it is preferable that the crystal structure before the repeated durability test is maintained.

  In the present application, the “repetitive durability test” is a test in which the operation of holding the zeolite in a vacuum vessel maintained at 90 ° C. and exposing it to a vacuum state and a saturated steam atmosphere at 90 ° C. for 90 seconds is repeated 500 times. It is. Here, “the crystal structure is retained” means that the strongest peak intensity after the repeated durability test is performed when the XRD measurement is performed with the same apparatus, the same measurement conditions, the same sample holder and the same sample weight. It means that it is 50% or more of the strongest peak intensity before the repeated durability test. The peak intensity is the peak height, and is defined by subtracting the background count from the peak top count.

  Further, when the zeolite of the present invention is subjected to repeated durability tests in the same manner as described above, the amount of water vapor adsorption at 25 ° C. and a relative vapor pressure of 0.5 is preferably 80% or more before the test.

  Further, the zeolite of the present invention preferably has a weight reduction rate (g1) of from 0 wt% to 3 wt% when heated from 200 ° C. to 350 ° C. The smaller weight loss rate (g1) is preferred, and the upper limit thereof is preferably 2% by weight, more preferably 1.5% by weight. When the weight reduction rate (g1) is too large, the thermal stability becomes insufficient.

  On the other hand, the weight reduction rate (g2) when the zeolite of the present invention is heated from 350 ° C. to 700 ° C. is preferably 2% by weight or more and 9.5% by weight or less. The weight loss rate (g2) is preferably 2.5% by weight or more, more preferably 3% by weight or more, and preferably 5.5% by weight or less. If the weight reduction rate (g2) is too small, the durability tends to be inferior, and if the weight reduction rate (g2) is too large, the amount of adsorption tends to be insufficient when zeolite is used as the adsorbent.

  The weight reduction rate is calculated by the following formulas 8 and 9, where w1 at 200 ° C., w2 at 350 ° C., and w3 at 700 ° C.

Weight reduction rate (g1) = (w1-w2) / w1 × 100 ... 8
Weight reduction rate (g2) = (w2-w3) / w1 × 100 ... 9

(Method for producing nitrogen-containing zeolite)
Next, the manufacturing method of the nitrogen containing zeolite of this invention is demonstrated.

  A method for producing a zeolite according to the present invention is a method for producing a zeolite according to the present invention having the above-mentioned composition and structural characteristics, wherein at least a compound of a metal element constituting the zeolite is used as a structure indicating material. It is produced by hydrothermal synthesis in the presence and calcining the obtained zeolite precursor in an atmosphere having an oxygen concentration of 0.1 vol% or more and 20 vol% or less.

  First, constituent raw materials for producing the zeolite according to the present invention will be described. As the constituent materials used, an aluminum source, a Me source (particularly preferably an iron source), a phosphorus source, and an organic template as a structure indicating material are used. And after mixing these each raw material, a zeolite precursor is obtained by carrying out hydrothermal synthesis.

  Aluminum source: The aluminum source is not particularly limited, and aluminum alkoxides such as pseudoboehmite, aluminum isopropoxide, aluminum triethoxide, aluminum hydroxide, alumina sol, sodium aluminate and the like are usually used. Among these, pseudoboehmite is preferably used from the viewpoint of ease of handling and reactivity.

  Me source; Me source that may be used is not particularly limited, and usually, inorganic acid salts such as sulfate, nitrate, phosphate, chloride, bromide, organic acids such as acetate, oxalate, citrate, etc. Organic metal compounds such as salts, pentacarbonyl and ferrocene are used. Of these, inorganic acid salts or organic acid salts are preferably used from the viewpoint of solubility in water. In some cases, a colloidal oxide may be used. As the Me source, those having a valence of Me of 2 are preferred. The type of Me is as described above.

  Phosphorus source: Phosphoric acid is usually used as the phosphorus source, but aluminum phosphate may be used.

  Organic template: As an organic template having a role as a structure indicating material in hydrothermal synthesis, amine, imine, and quaternary ammonium salt can be used. Preferably, (1) an alicyclic heterocycle containing nitrogen as a hetero atom It is preferable to use at least one compound selected from the group consisting of a compound, (2) an amine having a cycloalkyl group, and (3) an amine having an alkyl group. They are easy to obtain and inexpensive, and also have the effect that the (Me-) aluminophosphate produced is easy to handle and structural destruction is less likely to occur.

  Here, each said amine preferably used as an organic template is demonstrated in more detail.

  An alicyclic heterocyclic compound containing nitrogen as a heteroatom; The alicyclic heterocyclic compound containing nitrogen as a heteroatom is usually a 5- to 7-membered ring, preferably a 6-membered ring. The number of heteroatoms contained in the heterocycle is usually 3 or less, preferably 2 or less. The type of heteroatoms contained is not particularly limited except for nitrogen, but those containing oxygen in addition to nitrogen are preferred from the viewpoint of ease of synthesis. The positions of the heteroatoms are not particularly limited, but those in which the heteroatoms are not adjacent to each other are preferable from the viewpoint of ease of synthesis. The molecular weight is 250 or less, preferably 200 or less, more preferably 150 or less from the viewpoint of ease of synthesis.

  Examples of such alicyclic heterocyclic compounds containing nitrogen as a heteroatom include morpholine, N-methylmorpholine, piperidine, piperazine, N, N′-dimethylpiperazine, 1,4-diazabicyclo (2,2,2) octane. , N-methylpiperidine, 3-methylpiperidine, quinuclidine, pyrrolidine, N-methylpyrrolidone, hexamethyleneimine and the like. Of these, morpholine, hexamethyleneimine, and piperidine are preferred from the viewpoint of ease of synthesis, and morpholine is particularly preferred.

  An amine having a cycloalkyl group; In an amine having a cycloalkyl group, the number of cycloalkyl groups is preferably 2 or less, more preferably 1 per amine molecule. The cycloalkyl group usually has 5 to 7 carbon atoms, preferably 6 carbon atoms. The number of cycloalkyl cyclo rings is not particularly limited, but usually one is preferred. Moreover, it is preferable from the point of easiness of a synthesis | combination that the cycloalkyl group has couple | bonded with the nitrogen atom of the amine compound. The molecular weight is 250 or less, preferably 200 or less, more preferably 150 or less from the viewpoint of ease of synthesis.

  Examples of the amine having such a cycloalkyl group include cyclohexylamine, dicyclohexylamine, N-methylcyclohexylamine, N, N-dimethylcyclohexylamine, and cyclopentylamine, and cyclohexylamine is particularly preferable.

  An amine having an alkyl group; in an amine having an alkyl group, any number of alkyl groups may be contained in one amine molecule, but preferably three. The number of carbon atoms of the alkyl group is preferably 4 or less, and more preferably the total number of carbon atoms of all alkyl groups in one molecule is 10 or less. The molecular weight is 250 or less, preferably 200 or less, more preferably 150 or less from the viewpoint of ease of synthesis.

  Examples of amines having such alkyl groups include di-n-propylamine, tri-n-propylamine, tri-isopropylamine, triethylamine, triethanolamine, N, N-diethylethanolamine, N, N-dimethylethanol. Amine, N-methyldiethanolamine, N-methylethanolamine, di-n-butylamine, neopentylamine, di-n-pentylamine, isopropylamine, t-butylamine, ethylenediamine, di-isopropyl-ethylamine, N-methyl-n -Butylamine and the like, di-n-propylamine, tri-n-propylamine, tri-isopropylamine, triethylamine, di-n-butylamine, isopropylamine, t-butylamine, ethylenediamine, di-isopropyl Le - ethylamine, preferably in that N- methyl -n- butylamine synthetic ease, N, N- diethylethanolamine, N, N- dimethylethanolamine, triethylamine is more preferable. Most preferred are N, N-diethylethanolamine and triethylamine.

  The (1) alicyclic heterocyclic compound containing nitrogen as a hetero atom, (2) an amine having a cycloalkyl group, and (3) an amine having an alkyl group are preferably used alone or in combination of two or more. You may use together. When one of the above amines is used, from the viewpoint of ease of synthesis, (1) a morpholine in an alicyclic heterocyclic compound containing nitrogen as a hetero atom or (2) a cycloalkyl group Of the amines, cyclohexylamine is preferable, and morpholine is particularly preferable.

  On the other hand, in order to synthesize a desired composition with high purity, it is preferable to use a combination of two or more amines. Among these, as a preferable combination, as an organic template, (1) an alicyclic heterocyclic compound containing nitrogen as a hetero atom, (2) an amine having a cycloalkyl group, and (3) an amine having an alkyl group, It is preferable to use one or more compounds from two or more groups. By combining in this way, there is an advantage that it is easy to synthesize zeolite having a desired element ratio or high crystallinity. Among these, (1) in the case of a combination of two or more containing an alicyclic heterocyclic compound containing nitrogen as a heteroatom, a compound having a desired element ratio and a zeolite with high crystallinity are easily synthesized. As a specific preferred combination, a combination of two or more of morpholine, triethylamine or N, N-diethylethanolamine and cyclohexylamine, more preferably a combination of two or more containing morpholine is more preferable.

  The mixing ratio of each group of these organic templates needs to be selected as appropriate according to the conditions, but the molar ratio of the two organic templates to be mixed is in the range of 1:20 to 20: 1, and the desired element ratio From the viewpoint of ease of synthesis of zeolites having high crystallinity and high crystallinity, 1:10 to 10: 1 is preferable. In addition, although other organic templates may be contained, in that case, the molar ratio is usually preferably 20% or less, and more preferably 10% or less. These organic templates are advantageous in that they are inexpensive and easy to handle and less corrosive than conventional organic templates (eg, tetraethylammonium hydroxide).

  In the method for producing zeolite of the present invention, it is produced by using a plurality of organic templates in combination, and further by selecting the production conditions, (i) the crystallization speed in the zeolite synthesis process can be improved, ii) It is possible to easily produce a zeolite having a desired structure while suppressing the generation of impurities, and (iii) to produce a zeolite having a stable structure which is difficult to break.

  In the method for producing a zeolite of the present invention, an organic template obtained by combining a plurality of compounds selected from the above-described compounds (1) to (3) is preferably used, and a single organic template is produced by a synergistic action exhibited by these organic templates. There is an advantage that the effects (i) to (iii) which cannot be obtained by the above can be obtained.

  Next, hydrothermal synthesis in the method for producing zeolite according to the present invention will be described. Below, the case where Me is contained is demonstrated.

  First, an aqueous gel is prepared by mixing constituent materials consisting of a Me source, an aluminum source, a phosphoric acid source, an organic template and water. The order of mixing the constituent raw materials is not limited, and may be appropriately selected depending on the conditions to be used. Usually, however, first a phosphoric acid source and an aluminum source are mixed in water, and a Me source and an organic template are mixed therewith.

The composition of the aqueous gel affects the ease of synthesis of the desired one. When the aluminum source, the Me source, and the phosphate source are expressed by the molar ratio of the oxide, the value of MeO / Al ₂ O ₃ is usually larger than 0. 1.0 or less, preferably 0.02 or more, preferably 0.9 or less, more preferably 0.8 or less. The ratio of P ₂ O ₅ / Al ₂ O ₃ affects the ease of synthesis of the desired product, and is usually 0.6 or more, preferably 0.8 or more, more preferably 1 or more. It is 8 or less, preferably 1.7 or less, more preferably 1.6 or less.

The total amount of the organic template, affects the ease of synthesis and economics of desired ones, in a molar ratio of organic templates for P ₂ O ₅ (organic template / P 2 _{O 5),} usually 0.2 or more, preferably 0. 5 or more, more preferably 1 or more, and usually 4 or less, preferably 3 or less, more preferably 2.5 or less. In addition, the mixing ratio of two or more organic templates affects the ease of synthesis of the desired one and needs to be appropriately selected according to the conditions. As described above, for example, when morpholine and triethylamine are used, morpholine / Triethylamine molar ratio is 0.03 to 20, preferably 0.05 to 10, more preferably 0.1 to 9, and most preferably 0.2 to 4.

  The order of mixing one or more organic templates selected from each of the two or more groups is not particularly limited, and may be mixed with other substances after preparing the organic template. The mixture may be formulated after mixing with other substances.

The lower limit of the proportion of water, relative to _Al 2 _{O 3,} and at at least 3 molar ratio (water / _Al 2 _{O 3),} preferably 5 or more from the viewpoint of ease of synthesis, more than 10 Is more preferable. The upper limit of the ratio of water is 200 or less in terms of molar ratio (water / Al ₂ O ₃ ), preferably 150 or less, and more preferably 120 or less from the viewpoint of ease of synthesis and high productivity.

The pH of the aqueous gel is 4 to 10, preferably 5 to 9 and more preferably 5.5 to 7.5 from the viewpoint of ease of synthesis. The pH is adjusted by adjusting the amount of organic template added or by adding an acid such as hydrochloric acid or sulfuric acid. In addition, in order to improve the solubility of a raw material or the role of a mineralizer etc., you may coexist components other than the above in aqueous gel. Examples of such components include hydrophilic organic solvents such as hydroxides and salts of alkali metals and alkaline earth metals, and alcohols. The ratio of the coexisting component affects the ease of synthesis of the desired compound. In the case of a hydroxide or salt of an alkali metal or alkaline earth metal, the molar ratio with respect to Al ₂ O ₃ (coexisting component / Al ₂ O ₃ ) is usually 0.2 or less, preferably 0.1 or less, and in the case of a hydrophilic organic solvent such as alcohol, it is usually 0.5 or less, preferably 0.3 or less, in molar ratio to water. .

  Under such conditions, hydrothermal synthesis is performed by placing the aqueous gel in a pressure-resistant container and maintaining a predetermined temperature under stirring or standing under self-generated pressure or gas pressure that does not inhibit crystallization.

  The reaction temperature of hydrothermal synthesis affects the ease of synthesis of the desired product, and is usually 100 ° C. or higher, preferably 120 ° C. or higher, more preferably 130 ° C. or higher, and usually 300 ° C. or lower, preferably 250 ° C. or lower. More preferably, it is 180 ° C. or lower.

  The reaction time affects the ease of synthesis of the desired product, and is usually 2 hours or more, preferably 3 hours or more, more preferably 5 hours or more, and usually 30 days or less, preferably 10 days or less, more preferably 4 days or less. The reaction temperature may be constant during the reaction for this time or may be changed stepwise.

  After the hydrothermal synthesis, the product is separated. The method for separating the product is not particularly limited. Usually, the product is separated by filtration or decantation, washed with water, dried at a temperature of room temperature (25 ° C.) to 150 ° C. and below, and the zeolite containing the organic template as the product The precursor can be separated.

  Next, the firing step in the method for producing zeolite according to the present invention will be described.

  The calcining step is a process in which the zeolite precursor hydrothermally synthesized and separated as described above is heat-treated under predetermined conditions under a flow of air or the like diluted with nitrogen or under reduced pressure. Of the present invention containing the nitrogen and carbon.

  In this calcination step, the calcination conditions are controlled, and the removal of the organic template containing nitrogen is controlled to produce a zeolite containing a predetermined amount of nitrogen and carbon. In addition, after completely removing the organic template by firing, a predetermined amount of nitrogen and carbon is contained by adsorbing organic compounds such as organic amines such as methylamine and ethylamine in the pores after the organic template is completely removed. Zeolite may be produced. At this time, the organic template molecule containing nitrogen may remain in the zeolite while maintaining its structure, but the organic template remains in a structure in which at least a part of carbon or hydrogen is removed by causing a chemical reaction. It is preferable. The nitrogen-containing compound remaining in the zeolite preferably has a high nitrogen content relative to carbon as compared with the original organic template. For example, about 1.0 to 3.5 in terms of the C / N weight ratio. It is preferable that Whether or not the organic template remains can be confirmed by an analysis means such as CHN elemental analysis, thermogravimetric-mass spectrometry (TG-MASS), or the like.

  The firing temperature is usually 200 ° C. or higher and 800 ° C. or lower, preferably 250 ° C. or higher, more preferably 280 ° C. or higher, and particularly preferably 300 ° C. or higher. On the other hand, 700 ° C. or lower is preferable, 500 ° C. or lower is more preferable, and 440 ° C. or lower is still more preferable. By setting the firing temperature to 300 ° C. or higher and 440 ° C. or lower, there is an effect that the control of the carbon and nitrogen contents is easy. The firing time is a maximum temperature holding time of 1 minute to 15 hours, preferably 2 minutes to 10 hours, and more preferably 5 minutes to 8 hours. The pressure at the time of firing may be reduced pressure or increased pressure, but is usually performed at or near atmospheric pressure.

  Firing is usually performed in a gas containing oxygen in an inert gas. The lower limit of the oxygen concentration in the case where oxygen is contained in the gas is 0.1 vol%, preferably 0.5 vol% or more, more preferably 1 vol% or more, and further preferably 2 vol% or more. On the other hand, the upper limit of the oxygen concentration to be contained is 20 vol%, preferably 15 vol% or less, and more preferably 10 vol% or less. By containing oxygen in the gas and controlling the oxygen concentration in the gas within this range, there is an effect of suppressing the heat generation of the organic template during firing and facilitating the control of firing. Moreover, in order to avoid the rapid heat_generation | fever accompanying the oxidative decomposition | disassembly of an organic template, after baking in inert gas flow, such as nitrogen, it can also bake in oxygen-containing gas flow. In this case, since a part of the organic template is removed during firing in the inert gas, heat generation during firing in the second stage oxygen-containing gas can be suppressed. It becomes easy to control. As the gas other than oxygen, an inert gas such as nitrogen, argon, or helium is used, but in some cases, water vapor or nitrogen oxide may be mixed up to 10% by volume.

  In determining the firing conditions for obtaining the zeolite according to the present invention, it is preferable to verify the thermal decomposability of the zeolite precursor in advance and perform the firing at a temperature close to the temperature at which thermal decomposition starts and at a lower temperature. Therefore, in the above temperature range, it is preferable to adopt a relatively low temperature and to perform in the presence of a gas having a relatively low oxygen content from the viewpoint of improving durability.

  The zeolite having the characteristics of the present invention is produced by selecting from the above firing conditions based on the kind of constituent elements of the desired zeolite, the constituent ratio, the framework density, and the like. Among them, the above preferred structure indicating material is used, the firing temperature is set to 300 to 440 ° C., the firing time is set to 2 to 8 hours, and the conditions under an inert gas atmosphere containing oxygen in the ratio described in the preferred range are selected. There is a tendency to be obtained. As preferable baking conditions for producing the zeolite having the characteristics of the present invention, for example, in an inert gas containing 3 to 7 vol% of oxygen, a reaction condition of a baking temperature of 300 to 440 ° C. and a baking time of 4 to 8 hours is used. Can be mentioned.

  Further, when the zeolite having the characteristics of the present invention contains Me as an essential constituent element, the tendency to be obtained by performing in an inert gas atmosphere containing oxygen in a proportion described in the above preferred range as the firing condition. Furthermore, by performing firing at a relatively low temperature (for example, 300 to 400 ° C.) in the above firing temperature range in an inert gas atmosphere containing oxygen at a ratio described in the above preferred range. There is a tendency to be obtained.

The calcining gas may or may not be circulated in the calcining apparatus, but when it is circulated, the space velocity (GHSV) relative to the zeolite precursor to be calcined is within a predetermined range. It is preferable. As the space velocity (GHSV), 10 hr ^-1 or more, preferably 10000 hr ^-1 or less, 20 hr ^-1 or more, 3000 hr ^-1 or less is more preferable. If the GHSV is too small, removal of the organic template is delayed, and if the GHSV is too high, the gas flow rate required for firing is too large, which is economically undesirable. As a baking apparatus, arbitrary heating apparatuses, such as a muffle furnace, a tubular furnace, and a kiln, can be used, and it carries out in a fixed bed or a fluidized bed format. Here, GHSV is represented by “flowing gas volume / zeolite precursor volume” per unit time.

  By the above method, the zeolite according to the present invention containing a predetermined amount of nitrogen and carbon is produced.

(Use of nitrogen-containing zeolite)
The zeolite according to the present invention is widely used as a host for adsorbents, catalysts for acid reactions and oxidation reactions, separation materials, optical materials such as quantum dots and quantum wires, and semiconductor fine particles, phosphors and dyes that serve as magnetic materials. be able to. In particular, it is suitably used as an adsorbent because the crystal structure is hardly destroyed by repeated use and the deterioration of adsorption characteristics is small.

(Use as adsorbent)
The zeolite according to the present invention is preferably used as an adsorbent that is used repeatedly because it is excellent in durability, such as hardly causing structural destruction.

  In particular, it is preferably used as an adsorbent for a heat utilization system. For example, the adsorption heat generated by adsorption of an adsorbent on the adsorbent and / or the latent heat of vaporization of the adsorbent generated by evaporation of the adsorbent It can be suitably used as an adsorbent for the heat utilization system to be utilized. Note that the heat utilization system here refers to the use of thermal energy recovered as adsorption heat as a heat source for heating other substances and / or other thermal energy (cold heat) recovered as latent heat of evaporation. This means a system that is used as a heat source for cooling the substance, and specifically includes a cold storage heat system, an adsorption heat pump, a humidity control air conditioner for dehumidification and humidification, and the like.

  The zeolite of the present invention itself has an adsorption performance, but when used in the above heat utilization system, as its adsorption characteristic, a relative vapor pressure of 0.01 or more and 0.5 in an adsorption isotherm measured at 25 ° C. It is preferable that the adsorption amount change of the adsorbing substance (for example, water) when the relative vapor pressure changes by 0.15 in the following range has a relative vapor pressure region of 0.1 g / g or more. That is, a relatively hydrophilic material that can be desorbed at a relative vapor pressure of 0.01 or more and can be adsorbed at a relative vapor pressure of 0.5 or less is suitable. In the heat utilization system, a heat source having a high temperature of 150 ° C. or higher can be used depending on the system, and the relative humidity required for desorption can be sufficiently reduced. However, in the case of adsorption, since it is affected by the environment such as the outside air temperature, it is difficult to make the relative humidity larger than 0.5 necessary for the adsorption.

  Here, the operating vapor pressure range of the heat utilization system is determined by the desorption side relative vapor pressure (φ1a) and the adsorption side relative vapor pressure (φ2a). φ1 and φ2 can be calculated by the following formulas 10 and 11, and the range between φ1a and φ2a is an operable relative vapor pressure range.

Desorption side relative vapor pressure (φ1a) = Equilibrium vapor pressure (Tlow1) / Equilibrium vapor pressure (Thigh)… 10
Adsorption side relative vapor pressure (φ2a) = Equilibrium vapor pressure (Tcool) / Equilibrium vapor pressure (Tlow2)… 11

  Here, the equilibrium vapor pressure (Tlow1), the equilibrium vapor pressure (Thigh), the equilibrium vapor pressure (Tcool) and the equilibrium vapor pressure (Tlow2) mean the equilibrium vapor pressure at the temperature of Tlow1, Thigh, Tcool and Tlow2, respectively. . In this equation, Thigh (high temperature heat source temperature) is the temperature of the heating medium that is heated when the adsorbent is desorbed from the adsorbent and regenerated, and Tlow1 (low temperature heat source temperature) is the adsorbent of the condenser. Tlow2 (low temperature heat source temperature) is the temperature of the heat medium that cools the regenerated adsorbent when it is subjected to adsorption, and Tcool (cold heat generation temperature) is the temperature of the adsorbed material in the evaporator, that is, the generation The temperature of the cold. The equilibrium vapor pressure can be obtained from the temperature using the equilibrium vapor pressure curve of the adsorbed substance.

  In the adsorption process of the heat utilization system described above, the lower the low-temperature heat source temperature Tlow2, the greater the relative humidity necessary for adsorption and the wider the relative humidity that can be used. However, in practice, it is difficult to completely remove the heat of adsorption generated when the adsorbent adsorbs the adsorbed material, and it is also affected by environmental factors such as outside temperature. It is difficult to keep the temperature Tlow2 below 20 ° C. That is, when the adsorbed material is water, for example, when trying to obtain a cold heat generation temperature Tcool of 10 ° C., an operating relative water vapor pressure range greater than a relative humidity of 0.52 when the low temperature heat source temperature Tlow 2 is 20 ° C. It is not suitable for a heat utilization system.

  On the other hand, in the desorption process of the heat utilization system described above, the higher the high temperature heat source temperature Thigh, the smaller the relative humidity necessary for desorption and the wider the relative humidity that can be used. Depending on the system, it is possible to obtain a heat source having a high temperature heat source temperature Thigh of 100 ° C. or higher, and in some cases 120 ° C. or higher, or near 200 ° C. In this case, for example, when the low-temperature heat source temperature Thigh is 200 ° C. even if it is assumed that the low-temperature heat source temperature Tlow1 rises due to heat removal failure or environmental factors, and the low-temperature heat source temperature Tlow1 becomes 50 ° C. The relative humidity is about 0.01.

  From the above, in the heat utilization system of the present invention, it is preferable to use, as an adsorbent, the zeolite according to the present invention having an adsorption characteristic in which the amount of adsorption changes within a relative humidity range of 0.01 to 0.5. .

  The change in the amount of adsorption of the adsorbed material when the relative vapor pressure changes by 0.15 is 0.1 or more. This means that the adsorbed material (for example, water) suddenly changes with a relatively narrow relative vapor pressure change in the relative vapor pressure range. ) Changes in the adsorption amount. This amount of change means that the change in adsorption amount is large in a relatively narrow relative vapor pressure range, so the amount of adsorbent required to obtain an equivalent adsorption amount under the same conditions can be reduced, and the cooling heat source Even if the temperature difference between the heat source and the heating heat source is small, the heat utilization system can be driven.

Such adsorption properties, of the zeolites of the present invention, relatively framework intended density of small, e.g. 17.4T / nm ³ or less, preferably includes those 16T / nm ³ or less.

  When the zeolite of the present invention is used as an adsorbent, it may be used as a molded body. In the case of forming a molded body, care should be taken not to reduce the adsorption characteristics of the zeolite of the present invention as much as possible. Other components such as binders such as known binders for adsorbents and zeolites of the present invention can be used. It can be molded with a mixture in which other adsorbing substances are mixed. Examples of the binder include inorganic binders such as alumina, silica, and clay. The mixture is granulated by agitation granulation, granulation by spray granulation or the like, or a molding method (CIP) by hydrostatic pressure, and processed into a molded body. Moreover, you may crush a molded object as needed.

  The content of the zeolite of the present invention contained in the adsorbent is 60% by weight or more, preferably 70% by weight or more, and may be 100%. The case of 100% is a case where the adsorbent is composed of only the zeolite of the present invention as a constituent material.

(Application to cold storage system)
Next, the aspect which applied the adsorbent which consists of or contains the zeolite of this invention to the cool storage heat system is demonstrated.

  FIG. 1 is a conceptual diagram showing an example of a cold storage heat system of the present invention. The regenerative heat storage system 11 of the present invention includes an adsorption regenerative heat storage device that mainly includes a circulating water supply device 12, an adsorption / desorption device 13, and an evaporator / condenser 14. Here, the adsorption / desorption device 13 is an apparatus that includes an adsorbent and is supplied with an adsorbing substance (for example, water) from the evaporator / condenser 14 or supplies the adsorbing substance to the evaporator / condenser 14. The evaporator / condenser 14 is an apparatus that combines an evaporator for evaporating the adsorbed material and supplying it to the adsorption / desorption device 13, and a condenser for condensing the adsorbed material supplied from the adsorption / desorption device 13. . The circulating water supply device 12 is a device that supplies high temperature water A or low temperature water B to the adsorption / desorption device 13.

  The cold storage heat system 11 is configured to desorb an adsorbed substance (for example, water) from the adsorbent by supplying (configuration a) waste heat (circulated water of the circulating water supply device 12) to the adsorbent (in the adsorption / desorption device 13). And (configuration b-1) a configuration for supplying heat (adsorption heat) generated when the adsorbed material supplied from the evaporator / condenser 14 is adsorbed to the adsorbent to a device that requires a warm-up operation, And / or (configuration b-2) The latent heat of vaporization of the adsorbed material generated when the adsorbed material supplied from the evaporator / condenser 14 is adsorbed to the adsorbent is supplied to the cooling medium circulating in the cooling refrigerator. And a system.

  The adsorption-type regenerative heat storage device using the function of the adsorbent uses the ability of the adsorbent to adsorb and desorb the adsorbed material as a drive source. In the adsorption-type regenerative heat storage device, water, ethanol, acetone, or the like can be used as an adsorbent, but water is most preferable from the viewpoint of safety, price, and latent heat of vaporization, and the adsorbent is adsorbent as water vapor. To be adsorbed.

  As described above, the adsorbent comprising the zeolite itself of the present invention or the adsorbent containing it has mechanical characteristics and adsorption characteristics with excellent structural strength during repeated use. It can be suitably used as an adsorbent for use. Among them, an adsorbent having an adsorption characteristic with a large change in adsorption amount in a narrow relative vapor pressure range is particularly preferable because it can reduce the amount of adsorbent necessary to obtain an equivalent adsorption amount under the same conditions, and cooling. Even if the temperature difference between the heat source and the heating heat source is small, there is an advantage that the cold storage heat device can be driven.

(Application to adsorption heat pump)
Next, the aspect which applied the adsorption material which consists of or contains the zeolite of this invention to the adsorption heat pump is demonstrated.

  FIG. 2 is a conceptual diagram showing an example of the adsorption heat pump of the present invention. The adsorption heat pump 21 of the present invention includes an adsorbent, an adsorbent that adsorbs and desorbs the adsorbent, and adsorbers 22 and 23 that are filled with the adsorbent and transmit heat generated by the adsorption and desorption of the adsorbent to the heat medium. The evaporator 24 is mainly composed of an evaporator 24 for taking out the cold heat obtained by the evaporation of the adsorbing substance, and a condenser 25 for releasing the hot heat obtained by the condensation of the adsorbing substance to the outside. High-temperature water or low-temperature water is supplied to the adsorption / desorption devices 22 and 23 from the circulating water supply devices 26 and 27, and open / close valves 28 to 28 are provided between the adsorption / desorption devices 22 and 23, the evaporator 24, and the condenser 25. 31 is attached.

  The operating principle of the adsorption heat pump is, for example, (1) Open / close valves 29 and 30 are open, low temperature water is supplied to the adsorption / desorption device 22 from the circulating water supply device 26, and circulating water is supplied to the adsorption / desorption device 23. When high-temperature water is supplied from the vessel 27, (i) in the adsorption / desorption device 22, the adsorbent adsorbs the adsorbed substance (for example, water) supplied from the evaporator 24, and the adsorption heat generated during the adsorption is used. Hot water is obtained, and (ii) in the adsorber / desorber 23, the adsorbent desorbs the adsorbed material, and cold water is obtained by the latent heat of evaporation generated during the desorption. On the other hand, (2) the open / close valves 28 and 31 are open, high temperature water is supplied to the adsorption / desorption device 22 from the circulating water supply device 26, and low temperature water is supplied to the adsorption / desorption device 23 from the circulation water supply device 27. (I) in the adsorption / desorption device 22, the adsorbent desorbs the adsorbed material, and cold water is obtained by the latent heat of evaporation generated during the desorption, and (ii) in the adsorption / desorption device 23, the adsorbent is evaporated. The adsorbing substance (for example, water) supplied from the vessel 24 is adsorbed, and hot water is obtained by the adsorption heat generated during the adsorption.

  The adsorption heat pump 21 is a heat utilization system that can always obtain cooling water by repeating these two operations by operating an on-off valve. More detailed contents about the configuration and operating principle of such an adsorption heat pump are described in, for example, JP-A-2002-372332.

  The adsorption heat pump of the present invention is an adsorption heat pump to which the adsorbent comprising the zeolite of the present invention or an adsorbent containing the adsorbent is applied, and the adsorbent has excellent structural strength during repeated use as described above. Since it has mechanical characteristics and adsorption characteristics, it can be suitably used as an adsorbent for adsorption heat pumps. Among them, an adsorbent having an adsorption characteristic with a large change in adsorption amount in a narrow relative vapor pressure range is particularly preferable because it can reduce the amount of adsorbent necessary to obtain an equivalent adsorption amount under the same conditions, and cooling. There is an advantage that the adsorption heat pump can be driven even if the temperature difference between the heat source and the heating heat source is small.

(Application to dehumidifying air conditioner)
Next, the aspect which applied the adsorbent which consists of or contains the zeolite of this invention to the dehumidification air conditioner is demonstrated.

  FIG. 3 is a conceptual diagram showing an example of the dehumidifying air conditioner of the present invention. The dehumidifying air conditioner 61 of the present invention includes an adsorbent capable of adsorbing and desorbing an adsorbing substance (for example, water), an adsorption / desorption device 61 provided with the adsorbent, and a mechanism 63 for regenerating the adsorbent. It is. The dehumidifying air conditioner 61 is supplied with an air path (not shown) for circulating air 62 (also referred to as humidity conditioning air) for conditioning the humidity if necessary, or air after humidity conditioning. A device (not shown) for forced exhaust may be provided.

  The adsorber / desorber 61 only needs to have a shape that allows the adsorbent and the humidity control air 62 to be in sufficient contact. Examples of the shape include a rotor shape having a honeycomb structure.

  The mechanism 63 for regenerating the adsorbent may be any heat supply mechanism that can supply heat of about 80 ° C. necessary for the regeneration of the adsorbent to the adsorption / desorption device 61 in the case of (i) dehumidifying use. . Further, (ii) when heat is generated by electric heating or the like inside the apparatus, a heat source such as a heater or a heating coil, or a mechanism such as a blower for sufficiently transferring the heat to the adsorption / desorption device 61 may be used. Further, (iii) when a heat source is obtained from the outside of the apparatus, a mechanism such as a pipe for supplying the high-temperature gas may be used. The heat source from the outside at this time is not particularly limited like the adsorption heat pump, and examples thereof include cogeneration equipment such as a gas engine and a gas turbine, and a fuel cell. In the case of (iv) humidification applications, any route may be used as long as high-humidity air for reabsorption is circulated.

  An example of the humidity control method using the dehumidifying air conditioner will be specifically described with reference to FIG. 4, but is not limited thereto.

  FIG. 4 is a conceptual diagram of an example of a desiccant air conditioner that is a dehumidifying air conditioner. The desiccant air conditioner 70 includes a processing air path 71, a regeneration air path 72, a desiccant rotor 73 with adsorbent attached thereto, two sensible heat exchangers 74 and 75, a heat supply mechanism 76 from a heating source, The humidifier 77 is a main component. The processing air is dehumidified by the desiccant rotor 73 and the temperature rises due to the moisture adsorption heat of the desiccant. Thereafter, the treated air is cooled by exchanging heat with the regenerated air in the first sensible heat exchanger 74, then humidified by the humidifier 77, and supplied to the conditioned space 78. On the other hand, the regenerative air is taken in from the external space, heat-exchanged with the processing air in the first sensible heat exchanger 74 and heated, and then heated by the heat supply mechanism 76 to reduce the relative humidity. Passing through the desiccant rotor 73, the moisture of the desiccant rotor 73 is desorbed and regenerated. The sensible heat of the regenerated air after regeneration is recovered by exchanging heat with the regenerated air before heating by the second sensible heat exchanger 75 and then discharged to the outside 79.

  By applying the adsorbent comprising the zeolite of the present invention or an adsorbent containing the same to this dehumidifying air conditioner, the adsorbent has mechanical properties with excellent structural strength during repeated use as described above. And adsorbing properties, it can be suitably used as an adsorbent for a dehumidifying air conditioner.

  In accordance with the above principle, for example, it is possible to perform humidification by supplying the regenerated air in which moisture is adsorbed from the adsorbent into the room.

(Application and adsorption properties)
The heat utilization system using the zeolite of the present invention as an adsorbent uses the thermal energy recovered as adsorption heat as a heat source for heating other substances and / or the thermal energy recovered as latent heat of vaporization ( This is a system that uses (cold heat) as a heat source for cooling other substances. Specifically, as described above, a cold storage heat system, an adsorption heat pump, a humidity control air conditioner for dehumidification and humidification, and the like.

  In such a heat utilization system, an adsorbent (for example, water) is adsorbed on the adsorbent as a vapor, and the adsorbent is preferably a material having a large change in the amount of adsorbent adsorbed in a narrow relative vapor pressure range. This adsorption characteristic differs somewhat depending on the application for which the adsorbent is used.

  First, preferable adsorption characteristics when the adsorbent of the present invention is applied to an adsorption heat pump will be described.

  The adsorbent applied to the adsorption heat pump is the relative vapor pressure of the zeolite of the present invention contained in the adsorbent in the range of relative vapor pressure of 0.05 to 0.30 on the adsorption isotherm measured at 25 ° C. It is desirable that the change in the amount of adsorption of water as an adsorbent has a relative vapor pressure range of 0.1 g / g or more when the value changes by 0.15. At this time, the change in the amount of water adsorbed is preferably 0.12 g / g or more, more preferably 0.15 g / g or more, and still more preferably 0.18 g / g or more.

  The reason why such adsorption characteristics are preferable will be described in the case where the adsorption heat pump is driven by utilizing the relatively low temperature gas engine cogeneration at 100 ° C. or lower, the solid polymer fuel cell, or the exhaust heat of the automobile engine. The operation vapor pressure range when water is used as an adsorbent will be described.

  When an adsorption heat pump is driven using exhaust heat from a relatively low temperature gas engine cogeneration of 100 ° C. or lower, a polymer electrolyte fuel cell or an automobile engine, for example, the high temperature heat source temperature is 80 ° C. and the low temperature heat source temperature is In the case of 30 ° C., the operating vapor pressure range (φ1a to φ2a) is 0.09 to 0.29. Similarly, when the high temperature heat source temperature is 60 ° C. and the low temperature heat source temperature is 30 ° C., the operating relative water vapor pressure range (φ1a to φ2a) is 0.21 to 0.29. Further, when the case where an adsorption heat pump is driven using exhaust heat of an automobile engine based on the description in JP-A-2000-140625, the high-temperature heat source temperature is about 90 ° C. and the low-temperature heat source temperature is 30 ° C. In this case, the operation relative water vapor pressure range (φ1a to φ2a) is 0.06 to 0.29.

  Accordingly, when the adsorption heat pump is driven using the exhaust heat, the operation relative water vapor pressure range (φ1a to φ2a) is 0.05 to 0.30, more preferably 0.06 to 0.29. Become. Therefore, when regenerating the adsorbent by lowering the relative water vapor pressure by heating, use an adsorbent having an adsorption characteristic that completes desorption when the relative water vapor pressure is in the range of 0.05, preferably 0.06 or more. Is preferred. On the other hand, in terms of adsorption, it is preferable to use an adsorbent having an adsorption characteristic capable of obtaining a sufficient adsorption amount within a relative water vapor pressure of 0.30, preferably 0.29 or less.

  In view of the above, a material having a large change in the adsorption amount in the applied operating humidity range is preferred, and the relative water vapor pressure is generally 0.05 to 0.30, preferably 0.06 to 0.29. Thus, a material whose adsorption amount varies greatly is preferable.

  The adsorbent having the above adsorbing characteristics may be selected from adsorbents comprising or containing the zeolite of the present invention, and in particular, an alumino containing at least one kind of Me element selected from Fe, Ni, Co, Mg and Zn. Phosphate is preferred, and among them, Me is particularly preferred. Note that the skeleton structure is preferably a structure selected from AEI, CHA, and LEV, and the ratio of Me metal contained is the molar ratio of Me to the entire elements other than oxygen ((Me) / (Me + Al + P)) is 0.01 to 0.15, preferably 0.02 to 0.1.

  Next, preferable adsorption characteristics when the adsorbent of the present invention is applied to a cold storage heat system will be described.

  The adsorbent applied to the cold storage heat system has an adsorption amount of 0.15 g of the adsorbed substance at a relative vapor pressure of 0.02 on the adsorption isotherm measured at 55 ° C. in the zeolite of the present invention contained in the adsorbent. / G or less, the amount of adsorbed material adsorbed at a relative vapor pressure of 0.1 is 0.10 g / g or more, and the relative vapor pressure is 0.05 or more and 0.1 or less and the relative vapor pressure is 0.05. It is desirable to have a relative vapor pressure region where the amount of adsorption of the adsorbed material when changed is 0.05 g / g or more. Further, in the adsorption isotherm measured at 55 ° C., the adsorption amount of the adsorbent at a relative vapor pressure of 0.02 is 0.12 g / g or less, and the adsorption amount of the adsorbent at a relative vapor pressure of 0.1 is 0. .13 g / g or more, and relative vapor pressure at which the adsorption amount change of the adsorbed material becomes 0.08 g / g or more when the relative vapor pressure is changed by 0.05 in the range of relative vapor pressure of 0.02 or more and 0.1 or less. It is more desirable to have a pressure region. Further, the adsorption amount of the adsorbing substance at a relative vapor pressure of 0.02 is 0.04 g / g or less, and the adsorption amount of the adsorbing substance at a relative vapor pressure of 0.1 is 0.15 g / g or more. It is particularly desirable to have a relative vapor pressure region in which the adsorption amount change of the adsorbed material is 0.10 g / g or more when the relative vapor pressure is changed by 0.05 within a pressure range of 0.02 to 0.1.

  The reason why such an adsorption characteristic is preferable will be described with reference to a cold storage system installed in an automobile.

  In a cold storage heat system mounted on an automobile, the adsorption / desorption device is heated to about 90 ° C. by hot water heated at about 90 ° C., and the adsorbent in the heated adsorption / desorption device desorbs the adsorbed substance, The refrigerant circulating in the cooler is cooled by the latent heat of evaporation generated at that time, and the condenser is cooled to about 10 ° C. At this time, since the relative vapor pressure between them is about 0.02, it is preferable that the adsorption amount of the adsorbed substance at the relative vapor pressure 0.02 is small. When the temperature of the adsorption / desorption device is a low temperature of 90 ° C. or lower (for example, about 60 to 85 ° C.), or the temperature of the condenser is higher than 10 ° C. (for example, about 15 to 30 ° C.). Since the relative vapor pressure between them becomes larger than 0.02, it is necessary that sufficient desorption is performed at a relative vapor pressure higher than 0.02. Therefore, it is preferable that the adsorption amount of the adsorbed material under the condition of the relative vapor pressure of 0.02 is smaller.

  In automobiles and the like, the temperature of the adsorption / desorption device may be about 45 to 60 ° C. by the cooling water cooled by the radiator, and the temperature of the evaporator may be about 10 ° C. by the heat exchanger. In this case, since the relative vapor pressure between the adsorption / desorption device and the evaporator is about 0.10, it is preferable that the adsorption amount of the adsorbed substance at the relative vapor pressure 0.10 is large. That is, it is preferable to use an adsorbent having a large change in the amount of adsorption within this operating humidity range.

  The adsorbent having the above adsorbing characteristics may be selected from adsorbents comprising or including the zeolite according to the present invention, and in particular, (Me-) aluminophosphate, and iron aluminophosphate whose Me is Fe. It is desirable to be. The skeleton structure is preferably a CHA structure, and the ratio of the Me metal contained is 0.03 or more in terms of the molar ratio of Me to the entire elements other than oxygen forming the skeleton structure ((Me) / (Me + Al + P)). It is 0.25 or less, preferably 0.04 or more and 0.20 or less.

  As described above, the relationship between the heat utilization system and the adsorption characteristics taking the adsorption heat pump and the cold storage heat system as an example has been described, but when the zeolite having the above preferred adsorption characteristics is selected and the adsorbent containing the same is used, In addition to the durability of the adsorbent due to the performance of the zeolite of the present invention, as compared with the conventional adsorbent, the adsorption process occurs under a lower relative vapor pressure condition, and the desorption process is a higher relative vapor pressure condition. Will happen below. As a result, the adsorption amount changes due to a slight change in relative humidity, so an adsorption heat pump mounted on a car that has a problem that waste heat is generated and the fuel consumption further decreases by using an air conditioner, It can be preferably applied as an adsorbent for a cold storage heat system.

  As described above, the zeolite of the present invention and the adsorbent containing the same are used repeatedly, particularly when used as an adsorbent that repeatedly adsorbs and desorbs adsorbed substances because the carbon content is within a predetermined range. It has a preferable characteristic that the deterioration of the adsorption performance due to is small. Therefore, a heat utilization system that uses the adsorption heat generated by adsorption of the adsorbed substance on the adsorbent and / or the latent heat of vaporization of the adsorbed substance generated by evaporation of the adsorbed substance, specifically, a cold storage heat system, It has a beneficial effect of being able to withstand use under severe conditions such as adsorption heat pumps and dehumidifying air conditioners that perform adsorption and desorption, for example, several hundred thousand times or more.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. In addition, this invention is not limited at all by the following examples.

  First, each physical property in Examples and Comparative Examples was performed under the following measurement conditions.

<Powder X-ray diffraction (XRD) measurement conditions>
X-ray source: Cu-Kα ray (λ = 1.54Å)
Output setting: 40 kV, 30 mA
Optical conditions during measurement: Divergent slit = 1 °
Scattering slit: 1 °
Receiving slit: 0.2mm
Diffraction peak position: 2θ (diffraction angle)
Measurement range: 2θ = 4-50 °
Sample: About 100 mg of a sample pulverized manually using an agate mortar, and using a sample holder of the same shape, the amount of the sample was made almost constant.

<CN analysis>
PERKIN ELMER 2400 SeriesII CHNS / O Analyzer was used.

<Elemental analysis>
The sample was calcined at 550 ° C. for 6 hours under air flow, dissolved in hydrochloric acid, and then subjected to composition analysis by the ICP method.

<Weight reduction rate measurement>
The sample was subjected to thermogravimetric analysis under the conditions of a heating rate of 10 ° C./min and a sample of about 10 mg under a flow of air of 10 ml / min. From the weights of 200 ° C., 350 ° C. and 700 ° C., the weight reduction rate (g1) The weight reduction rate (g2) was determined.

<Adsorption characteristics (25 ° C.)>
The water vapor adsorption amount at 25 ° C. was measured with a water vapor adsorption amount measuring device (Belsorb 18: manufactured by Nippon Bell Co., Ltd.).

Air temperature chamber: 50 ° C
Adsorption temperature: 25 ° C
Initial introduction pressure: 3.0 torr
Introduced pressure setting points: 0
Saturated vapor pressure: 23.755 torr
Equilibrium time: 500 seconds Sample: Measured after evacuation at 120 ° C. for 5 hours.

<Adsorption characteristics (55 ° C.)>
The water vapor adsorption amount at 55 ° C. was measured by a water vapor adsorption amount measuring device (Belsorb 18: manufactured by Nippon Bell Co., Ltd.) by the following method.

Air temperature chamber: 60 ° C
Adsorption temperature: 55 ° C
Initial introduction pressure: 3.0 torr
Introduced pressure setting points: 0
Saturated vapor pressure: 118.11 torr
Equilibrium time: 500 seconds Sample: Measured after evacuation at 120 ° C. for 5 hours.

<Durability test # 1>
About 0.5 g of sample is placed in a glass container with an inner diameter of about 20 mm (opening inner diameter of about 15 mm) and a height of about 40 mm, and installed in an environment maintained at 25 ° C. and humidity of 60% in an oven capable of temperature programming. Put it in. As the temperature cycle in the oven, after holding at 40 ° C. for 20 minutes, the temperature is raised to 100 ° C. at 2 ° C./minute, held at 100 ° C. for 20 minutes, and then cooled to 40 ° C. at 2 ° C./minute. This cycle was repeated 100 times.

<Durability test # 2>
The operation of holding the sample in a vacuum vessel maintained at 90 ° C. and exposing it to a vacuum state and a saturated steam atmosphere at 90 ° C. for 90 seconds was repeated 500 times.

Example 1
Hydrothermal synthesis and calcination were performed to produce a nitrogen-containing zeolite as follows.

  First, 11.53 g of 85% phosphoric acid was added to 28.05 g of water, and 5.44 g of pseudoboehmite (containing 25% water, manufactured by Condea) was slowly added thereto and stirred. This was designated as liquid A. Separately from Liquid A, a liquid was prepared by mixing 5.56 g of ferrous sulfate heptahydrate, 4.35 g of morpholine, 5.06 g of triethylamine and 29 g of water. This was slowly added to the liquid A and stirred for 3 hours to obtain a gel-like starting reaction product having the following composition.

_{0.4FeSO 4: 0.8Al 2 O 3:} P 2 O 5: 1.0 morpholine: 1.0 triethyl amine: 70H ₂ O

  The obtained starting reaction product was charged into a 200 cc stainless steel autoclave containing a Teflon (registered trademark) inner cylinder and allowed to react at 180 ° C. for 1 day in a stationary state. After the reaction, the reaction mixture was cooled and the supernatant was removed by decantation to collect a precipitate. The precipitate was washed three times with water, filtered, and dried at 120 ° C. to obtain a zeolite precursor. The zeolite precursor was identified by powder X-ray diffraction (XRD) and found to have a pure CHA structure.

  Thermogravimetric analysis was performed using a part (13 mg) of the dried zeolite precursor. Thermogravimetric analysis was performed at 10 ° C from room temperature (25 ° C) to 700 ° C while circulating air (oxygen concentration 7 vol%) diluted with helium at 30 mL / min using a thermogravimetric analyzer (Shimadzu Corporation TGA-50). The temperature was raised at / min. The result is shown in FIG.

Next, 3 g was collected from the obtained zeolite precursor, put into a vertical quartz fired tube, and 0.35 air was circulated through a mixed gas (oxygen concentration 7 vol%) of 175 mL / min and nitrogen 325 mL / min. The temperature was raised to 350 ° C. at a rate of 350 ° C./minute, and the calcination was carried out for 6 hours at 350 ° C. (this temperature is a temperature near the decomposition temperature by thermogravimetric analysis shown in FIG. 5). I got a thing. This fired product was identified by XRD. FIG. 6 shows the obtained diffraction pattern, which was found to be a pure CHA structure (framework density 14.5 T / nm ³ ).

  According to CN analysis of the fired product, carbon was 2.3% by weight, nitrogen was 1.1% by weight, and the C / N weight ratio was 2.12. The results of elemental analysis were Al: 37.8 mol%, P: 50 mol%, and Fe: 12.2 mol% in terms of the constituent ratio (molar ratio) of each component with respect to the total of Al, P, and Fe. The water vapor adsorption amount (25 ° C.) was 27% by weight. The adsorption isotherm as shown in FIG. 7 was obtained by measuring the adsorption characteristics (55 ° C.) of the fired product. The pore utilization rate determined from the above formula 7 was 0.9. The water vapor adsorption amount after the durability test # 1 of the fired product was 27% by weight at 25 ° C. and relative vapor pressure P / Ps = 0.5, and no decrease was observed. FIG. 8 is an XRD pattern after the durability test # 1 of the fired product, in which a CHA structure was confirmed and no significant decrease in crystallinity was observed. At this time, the weight of the XRD measurement sample before and after repetition was substantially constant. As a result of observing the particles before and after durability test # 1 of the fired product, the particles were not crushed. FIG. 9 is an XRD pattern after the durability test # 2 of the fired product, and a CHA structure was confirmed. The amount of water vapor adsorbed at 25 ° C. and a relative vapor pressure of 0.5 in the fired product after the durability test # 2 was 27% by weight. Further, the weight reduction rate (g1) and the weight reduction rate (g2) of the fired product were measured. These results are shown in Table 1.

(Example 2)
In Example 1, a calcined product that was a nitrogen-containing zeolite was obtained in the same manner as in Example 1 except that the calcining temperature was 340 ° C. and the oxygen concentration in the flow gas was 5 vol%.

  The obtained fired product had a nitrogen content of 1.7% by weight, a carbon content of 3.1% by weight, and a C / N weight ratio of 1.83. From the XRD pattern measured in the same manner as in Example 1, it was found to be a pure CHA structure. The water vapor adsorption amount (25 ° C.) was 27% by weight. The pore utilization rate determined from the above formula 7 was 0.9. When durability test # 1 was performed, no decrease in the amount of adsorption was observed, and there was no change in crystallinity. Further, the weight reduction rate (g1) and the weight reduction rate (g2) of the fired product were measured. The results are shown in Table 1.

(Example 3)
In Example 1, a calcined product that was a nitrogen-containing zeolite was obtained in the same manner as in Example 1 except that the calcining temperature was 400 ° C. and the oxygen concentration in the flow gas was 0.2 vol%.

The obtained fired product had a nitrogen content of 1.7% by weight, a carbon content of 5.0% by weight, and a C / N weight ratio of 2.86. From the XRD pattern measured in the same manner as in Example 1, it was found to be a pure CHA structure (framework density 14.5 T / nm ³ ). The water vapor adsorption amount (25 ° C.) was 23% by weight. The pore utilization factor obtained from the above formula 7 was 0.77. When durability test # 1 was performed, no decrease in the amount of adsorption was observed, and there was no change in crystallinity. Further, the weight reduction rate (g1) and the weight reduction rate (g2) of the fired product were measured. The results are shown in Table 1.

  In addition, in any of the nitrogen-containing zeolites of Examples 1 to 3, the skeletal structure before calcination is maintained when the calcination is performed so that the carbon content is less than 0.3% by weight. . The nitrogen-containing zeolite obtained in Examples 1 to 3 retains the crystal structure before the repeated durability test when the repeated durability test is performed according to the following.

  <Repeated durability test>: The operation of holding the zeolite in a vacuum container maintained at 90 ° C. and exposing it to a vacuum state and a saturated steam atmosphere at 90 ° C. for 90 seconds is repeated 500 times.

  Further, when the repeated durability test is performed according to the above, the water vapor adsorption amount at 25 ° C. and the relative vapor pressure of 0.5 is 80% or more before the repeated durability test.

(Comparative Example 1)
In Example 1, a fired product that was iron aluminophosphate was obtained in the same manner as in Example 1 except that the firing temperature was 550 ° C.

The obtained fired product had a nitrogen and carbon content of less than the lower limit of measurement (0.3% by weight). From the XRD pattern measured in the same manner as in Example 1, it was found to be a pure CHA structure (framework density 14.5 T / nm ³ ). The water vapor adsorption amount (25 ° C.) was 30% by weight. The pore utilization rate obtained from the above formula 7 was 1. When durability test # 1 was performed, the amount of adsorption after the test was greatly reduced to 15% by weight. 10 and 11 show XRD patterns before and after the durability test # 1, and a decrease in crystallinity after the test was observed. Further, the weight reduction rate (g1) and the weight reduction rate (g2) of the fired product were measured. The results are shown in Table 1.

(Comparative Example 2)
11.5 g of 85% phosphoric acid was added to 26 g of water, and 5.44 g of pseudoboehmite (containing 25% water, manufactured by Condea) was slowly added thereto and stirred for 2 hours. A solution prepared by dissolving 8.3 g of ferrous sulfate heptahydrate in 26 g of water was added thereto, and a solution obtained by mixing 2.18 g of morpholine and 7.43 g of cyclohexylamine was slowly added thereto, followed by further stirring for 2 hours. And the gel-like starting reaction material which has the following compositions was obtained.

_{0.6FeSO 4: 0.8Al 2 O 3:} P 2 O 5: 0.5 morpholine: 1.5 cyclohexylamine: 60H ₂ O

  The obtained starting reaction product was charged into a 0.2 L stainless steel autoclave containing a Teflon (registered trademark) inner cylinder and allowed to react at 200 ° C. for 12 hours in a stationary state. After the reaction, the reaction mixture was cooled and the supernatant was removed by decantation to collect a precipitate. The precipitate was washed with water three times, filtered off and dried at 120 ° C. The obtained solid was fired in the same manner as in Comparative Example 1 to obtain a fired product that was iron aluminophosphate.

The obtained fired product had a nitrogen and carbon content of less than the lower limit of measurement (0.3% by weight). As a result of elemental analysis, the constituent ratio (molar ratio) of each component with respect to the total of Al, P and Fe was Al: 36.9 mol%, P: 50 mol%, Fe: 13.1 mol%. The XRD pattern revealed a pure CHA structure (framework density 14.5 T / nm ³ ). The water vapor adsorption amount (25 ° C.) was 30% by weight. The pore utilization rate obtained from the above formula 7 was 1. As a result of durability test # 1, the amount of adsorption after the test was greatly reduced to 10% by weight. 12 and 13 are XRD patterns before and after the durability test, and a decrease in crystallinity after the test was observed. Further, when the particles after the durability test were observed, they were completely pulverized. Further, the weight reduction rate (g1) and the weight reduction rate (g2) of the fired product were measured. The results are shown in Table 1.

(Comparative Example 3)
Hydrothermal synthesis, drying and firing were performed in the same manner as in Comparative Example 1. 1 g of the obtained solid was filled in a Pyrex (registered trademark) tube having an inner diameter of 6 mm and treated at 300 ° C. for 2 hours under a flow of He gas of 500 mL / hr. After allowing to cool to room temperature (25 ° C.) under He flow, the flow gas was switched to He gas containing 10 vol% of ammonia (NH ₃ ) at 500 mL / hr and treated at room temperature (25 ° C.) for 2 hours. Thereafter, the flow gas was switched to He gas and purged at room temperature (25 ° C.).

As a result of CN analysis of the obtained solid, nitrogen was 11.5% by weight and carbon was less than the lower limit of detection (0.3% by weight). After the solid was evacuated at 80 ° C. for 3 hours, the water vapor adsorption amount at 30 ° C. and a relative vapor pressure of 0.5 was 30% by weight. The pore utilization rate obtained from the above formula 7 was 1. FIG. 14 is an XRD pattern of a solid treated with NH ₃ and was found to have a CHA structure (framework density 14.5 T / nm ³ ). FIG. 15 is an XRD pattern after durability test # 1 of a solid treated with NH ₃ , and it was confirmed that the solid was amorphous. From these results, it is clear that the pore structure of the zeolite is almost completely destroyed and the water vapor adsorption amount is greatly reduced. Further, the weight reduction rate (g1) and the weight reduction rate (g2) of the fired product were measured. The results are shown in Table 1.

(Comparative Example 4)
A solid was obtained in the same manner as in Example 1 except that the firing gas was nitrogen and the firing temperature was 325 ° C.

  As a result of CN analysis, nitrogen was 2.7% by weight and carbon was 10.0% by weight, which were outside the scope of the present invention. The water vapor adsorption amount (25 ° C.) of this solid was 7.1% by weight. The pore utilization factor obtained from the above formula 7 was 0.24. It is clear that the amount of adsorption is inferior compared to the amount of water vapor adsorption (27% by weight) of the zeolite of Example 1 within the scope of the present invention. Further, the weight reduction rate (g1) and the weight reduction rate (g2) of the fired product were measured. The results are shown in Table 1.

(Comparative Example 5)
An iron aluminophosphate with a nitrogen content below the lower limit of the scope of the present invention was synthesized according to Example 11 of US Pat. No. 4,554,143.

  11.6 g of 85% phosphoric acid was added to 32 g of water, and 16.4 g of aluminum isopropoxide was slowly added thereto, followed by stirring for 3 hours. To this, 5.6 g of ferrous sulfate heptahydrate was added, and a solution prepared by mixing 42.1 g of a 35 wt% tetraethylammonium hydroxide (TEAOH) aqueous solution was further added, followed by further stirring for 3 hours. A gel-like starting reaction product having the following composition was obtained.

_{0.4FeSO 4: 0.8Al 2 O 3:} P 2 O 5: 2.0TEAOH: 68H 2 O

  The obtained starting reaction product was charged into a 0.2 L stainless steel autoclave containing a Teflon (registered trademark) inner cylinder, and allowed to react at 200 ° C. for 42 hours in a stationary state. After the reaction, the reaction mixture was cooled and the precipitate was collected by a centrifuge. The precipitate was washed with water, filtered off and dried at 120 ° C. The solid after drying was found to have a CHA structure from the XRD pattern. According to elemental analysis, the constituent ratio (molar ratio) of each component with respect to the total of Al, P and Fe was Al: 44.7 mol%, P: 50 mol%, and Fe: 4.3 mol%.

  A part of the obtained template-containing zeolite was sampled and calcined in the same manner as in Example 1 except that the calcining temperature was 450 ° C., the flow gas was nitrogen, and the calcining time was 2 hours.

The solid after firing was found to have a CHA structure (framework density 14.5 T / nm ³ ) by XRD measurement. The nitrogen content of the zeolite obtained by calcination was less than the lower limit of measurement (0.3 wt%), and the carbon content was about 10 wt%, which was outside the scope of the present invention. The water vapor adsorption amount of the obtained solid at 25 ° C. and relative vapor pressure 0.5 was 20% by weight.

  Durability test # 2 was performed on the obtained solid. The amount of water vapor adsorption at 25 ° C. and a relative vapor pressure of 0.5 after the test was 10% by weight, which was reduced to 50% before the test. Further, the weight reduction rate (g1) and the weight reduction rate (g2) of the fired product were measured. The results are shown in Table 1.

It is a conceptual diagram which shows an example of the cool storage heat system of this invention. It is a conceptual diagram which shows an example of the adsorption heat pump of this invention. It is a conceptual diagram which shows an example of the dehumidification air conditioner of this invention. It is a conceptual diagram of an example of the desiccant air conditioner which is a dehumidification air conditioner. 2 is a result of thermogravimetric analysis of the zeolite precursor obtained in Example 1. FIG. It is a XRD pattern before the durability test # 1 of the baked product obtained in Example 1. 2 is a water vapor adsorption isotherm at 55 ° C. of the fired product obtained in Example 1. FIG. It is an XRD pattern after durability test # 1 of the fired product obtained in Example 1. It is an XRD pattern after durability test # 2 of the fired product obtained in Example 1. It is an XRD pattern before the durability test # 1 of the baked product obtained in Comparative Example 1. It is an XRD pattern after durability test # 1 of the fired product obtained in Comparative Example 1. It is a XRD pattern before durability test # 1 of the baked product obtained in Comparative Example 2. It is an XRD pattern after durability test # 1 of the fired product obtained in Comparative Example 2. It is an XRD pattern before the durability test # 2 of the baked product obtained in Comparative Example 3. It is a XRD pattern after durability test # 2 of the baked product obtained in Comparative Example 3.

Explanation of symbols

11 Cold storage heat system 12, 26, 27 Circulating water supply 13, 22, 23 Adsorption / desorption device 14 Evaporator / condenser 21 Adsorption heat pump 24 Evaporator 25 Condenser 28, 29, 30, 31 Open / close valve 61 Dehumidifying air conditioner 62 Air 63 Adsorbent regeneration mechanism 70 Desiccant air conditioner 71 Processing air path 72 Regeneration air path 73 Desiccant rotor 74, 75 Sensible heat exchanger 76 Heat supply mechanism 77 Humidifier 78 Air conditioning space 79 External

Claims (25)

  The nitrogen content is 0.5 wt% or more and 12 wt% or less, the carbon content is 1 wt% or more and 8 wt% or less, and the aluminum is Me (where Me is the periodic table group 2A, 7A group, 8 group) Zeolite characterized by being an aluminophosphate that may be partially substituted with at least one element selected from Group 1B and Group 2B elements.   2. The zeolite according to claim 1, wherein the weight ratio of carbon to nitrogen (C / N weight ratio) is 0.8 or more and 6.5 or less.   The zeolite according to claim 2, wherein the C / N weight ratio is 1.0 or more and 4.0 or less. The molar ratio of Me, Al, and P constituting the skeleton structure of the aluminophosphate that may contain Me satisfies the following formulas 1 to 3. The zeolite according to item 1.
0 ≦ x ≦ 0.3… 1
(X represents the molar ratio of Me to the sum of Me, Al and P)
0.2 ≦ y ≦ 0.6 2
(Y represents the molar ratio of Al to the sum of Me, Al and P)
0.3 ≦ z ≦ 0.6 3
(Z represents the molar ratio of P to the sum of Me, Al and P) The zeolite according to claim 4, wherein the molar ratio of Me satisfies the following formula 1 '.
0.001 ≦ x ≦ 0.3… 1 ′
(X represents the molar ratio of Me to the sum of Me, Al and P) Framework density 10T / nm ³ or more 17.4T / nm ³ zeolite according to any one of claims 1 to 5, wherein the less. The skeletal structure is a structure selected from AEI, AFR, AFS, AFT, AFX, ATS, CHA, ERI , LEV, LTA and VFI represented by a code defined by IZA. The zeolite according to any one of the above.   The zeolite according to any one of claims 1 to 6, wherein the skeleton structure is a structure selected from AEI, CHA, and LEV represented by a code defined by IZA.   The zeolite according to any one of claims 1 to 8, wherein Me is at least one element selected from Fe, Ni, Co, Mg and Zn.   The zeolite according to any one of claims 1 to 8, wherein Me is Fe.   The zeolite according to any one of claims 4 to 10, wherein a molar ratio of nitrogen to Me is 0.2 or more and 3 or less. The zeolite according to any one of claims 1 to 11, wherein when a repeated durability test of the zeolite is conducted according to the following, the crystal structure before the test is maintained.
The “repetitive durability test” is a test in which the operation of holding the zeolite in a vacuum vessel maintained at 90 ° C. and exposing it to a vacuum state and a saturated steam atmosphere at 90 ° C. for 90 seconds is repeated 500 times. “Crystal structure is retained” means that when XRD measurement is performed with the same equipment, the same measurement conditions, the same sample holder and the same sample weight, the strongest peak intensity after the repeated durability test is the repeated durability test. It means 50% or more of the previous strongest peak intensity. However, the peak intensity is the peak height, and is obtained by subtracting the background count from the peak top count. A method for producing a zeolite according to any one of claims 1 to 12,
Hydrothermal synthesis of at least a metal element compound constituting the zeolite in the presence of a structure indicating material, and the obtained zeolite precursor is calcined in an atmosphere having an oxygen concentration of 0.1 vol% or more and 20 vol% or less. A method for producing zeolite.   The method for producing a zeolite according to claim 13, wherein the temperature at which the zeolite precursor is calcined is 300 ° C or higher and 440 ° C or lower.   A zeolite precursor is hydrothermally synthesized in the presence of two or more kinds of structure indicating materials, and the structure indicating material includes (1) an alicyclic heterocyclic compound containing nitrogen, and (2) a cycloalkyl group. The method for producing a zeolite according to claim 13 or 14, wherein the zeolite is selected from two or more of the group consisting of: an amine having an amine; and (3) an amine having an alkyl group.   Zeolite precursors are morpholine, cyclohexylamine, triethylamine, isopropylamine, N, N-diisopropylethylamine, N-methyl-n-butylamine, isobutylamine, hexamethyleneimine, N, N-diethylethanolamine and N, N- The method for producing a zeolite according to claim 13 or 14, which is synthesized in the presence of at least one nitrogen-containing organic compound selected from dimethylethanolamine as a structure indicating material.   An adsorbent comprising the zeolite according to any one of claims 1 to 12.   In the adsorption isotherm measured at 25 ° C., the adsorption amount change of the adsorbed material is 0.1 g / g when the relative vapor pressure changes 0.15 in the range of the relative vapor pressure 0.01 to 0.5. The adsorbent according to claim 17, which has the above relative vapor pressure region.   To be used in a heat utilization system that uses adsorption heat generated by adsorption of an adsorbent on the adsorbent and / or a heat utilization system that uses latent heat of evaporation generated when the adsorbent evaporates from the adsorbent. The adsorbent according to claim 17 or 18, wherein:   The heat utilization system includes (a) a structure for supplying waste heat to the adsorbent and desorbing the adsorbent, and (b-1) warming up the adsorption heat generated when the adsorbent is adsorbed on the adsorbent. A configuration for supplying equipment that needs operation, and / or (b-2) a configuration for supplying latent heat of evaporation generated when the adsorbed material evaporates from the adsorbent to a cooling medium circulating in the cooling refrigerator; The adsorbent according to claim 19, wherein the adsorbent is a cold storage heat system.   The adsorbent used in the cold storage heat system, wherein the zeolite contained in the adsorbent has a relative vapor pressure in the range of relative vapor pressure of 0.02 to 0.1 on the adsorption isotherm measured at 55 ° C. 21. The adsorbent according to claim 20, wherein the adsorbent has a relative vapor pressure region in which a change in the amount of adsorption of the adsorbed substance when 0.05 changes is 0.05 g / g or more.   The adsorbent according to claim 19, wherein the heat utilization system is an adsorption heat pump.   The heat utilization system using the adsorbent according to any one of claims 17 to 19, wherein the heat utilization system using adsorption heat generated by adsorption of the adsorbent on the adsorbent and / or the adsorbent A heat utilization system, characterized by being a heat utilization system that utilizes latent heat of vaporization that evaporates from an adsorbent.   An adsorption heat pump using the adsorbent according to any one of claims 17 to 19.   A cold storage heat system using the adsorbent according to any one of claims 17 to 19.

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