(12) United States Patent
`Zones et al.
`
`111111
`
`1111111111111111111111111111111111111111111111111111111111111
`US006709644B2
`
`(10) Patent No.:
`(45) Date of Patent:
`
`US 6, 709,644 B2
`Mar.23,2004
`
`(54) SIVIALL CRYSTALLITE ZEOLITE CHA
`
`(56)
`
`References Cited
`
`(75)
`
`Inventors: Stacey I. Zones, San Francisco, CA
`(US); Lun-Teh Yuen, San Francisco,
`CA (US); Stephen J. Miller, San
`Francisco, CA (US)
`
`(73) Assignee: Chevron U.S.A. Inc., San Ramon, CA
`(US)
`
`( *) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 154(b) by 331 days.
`
`(21) Appl. No.: 09/943,723
`
`(22) Filed:
`
`Aug. 30, 2001
`
`(65)
`
`Prior Publication Data
`
`US 2003/0069449 A1 Apr. 10, 2003
`
`(51)
`
`Int. Cl? ........................... COlB 39/48; C07C 4/00;
`C07C 209/16; BOlD 53/02
`(52) U.S. Cl. ....................... 423/706; 423/712; 423/716;
`423/213.2; 423/213.5; 423/239.2; 95!90;
`564/474; 564/479; 585/640
`(58) Field of Search ................................. 423/706, 712,
`423/716, 213.2, 213.5, 239.2; 95!90; 564/474,
`479; 585/640
`
`U.S. PATENT DOCUMENTS
`
`10/1985 Zones
`4,544,538 A
`4/1988 Abrams eta!.
`4,737,592 A
`5,191,141 A * 3/1993 Barger eta!. ............... 585/640
`2003/0104931 A1 * 6/2003 Mertens eta!. ............. 502/214
`
`OTHER PUBLICATIONS
`
`Szostak, Handbook of Molecular Sieves, Van Nostrand
`Reinhold, 1992, pp. 117-124.
`Szostak, Handbook of Molecular Sieves, Van Nostrand
`Reinhold, 1992, pp. 448-449.
`
`* cited by examiner
`
`Primary Examiner-David Sample
`(74) Attorney, Agent, or Finn-Richard J. Sheridan
`
`(57)
`
`ABSTRACT
`
`The present invention relates to zeolites having the crystal
`structure of chabazite (CHA) and having small crystallite
`size, to processes using the small crystallite CHA as a
`catalyst, and to gas separation processes using the small
`crystallite CHA.
`
`21 Claims, No Drawings
`
`Umicore AG & Co. KG
`Exhibit 1004
`Page 1 of 5
`
`

`
`US 6,709,644 B2
`
`1
`SMALL CRYSTALLITE ZEOLITE CHA
`
`BACKGROUND OF THE INVENTION
`
`FIELD OF THE INVENTION
`
`The present invention relates to crystalline zeolite SSZ-62
`that has the CHA crystal structure, a mole ratio greater than
`10 of silicon oxide to aluminum oxide and has a crystallite
`size of 0.5 micron or less. The present invention also relates
`to a method for preparing SSZ-62 using specific sources of
`silicon and aluminum, and a N,N,N-trimethyl-1-
`adamantammonium cation templating agent, to processes
`employing SSZ-62 as a catalyst, and to processes using
`SSZ-62 to separate gasses.
`
`SUMMARY OF THE INVENTION
`
`2
`The present invention further provides a process for
`producing dimethylamine comprising reacting methanol
`and/or dimethyl ether and ammonia in the gaseous phase in
`the presence of a catalyst comprising a zeolite having the
`5 CHA crystal structure, a mole ratio greater than about 10 of
`silicon oxide to aluminum oxide and having a crystallite size
`of 0.5 micron or less.
`Further provided by the present invention is an improved
`process for separating gasses using a membrane containing
`10 a zeolite, the improvement being the use in the membrane of
`a zeolite having the CHA crystal structure, a mole ratio
`greater than about 10 of silicon oxide to aluminum oxide and
`having a crystallite size of 0.5 micron or less.
`DETAILED DESCRIPTION OF THE
`INVENTION
`In preparing SSZ-62 zeolites, a N,N,N-trimethyl-1-
`adamantammonium cation is used as a crystallization tem(cid:173)
`plate or structure directing agent ("SDA"). In general,
`SSZ-62 is prepared by contacting an aluminum hydroxide
`20 gel dried to about 50 wt. % Al2 0 3 with a slight alkalinity and
`the ability to absorb C02 and solubilize rapidly in water,
`precipitated silica with a water content of about 5-15 wt. %
`with the SDA in an aqueous solution.
`SSZ-62 is prepared from a reaction mixture having the
`25 composition shown in Table A below. Silicon- and
`aluminum-containing reactants are expressed as Si02 and
`~03, respectively.
`
`15
`
`The present invention is directed to a family of crystalline
`molecular sieves with unique properties, referred to herein
`as ''zeolite SSZ-62" or simply "SSZ-62". Preferably, SSZ-62
`is obtained in its aluminosilicate form. As used herein, the
`term "aluminosilicate" refers to a zeolite containing both
`alumina and silica.
`In accordance with this invention, there is provided a
`zeolite having the CHAcrystal structure, a mole ratio greater
`than about 10 of an oxide of a first tetravalent element to an
`oxide of a second tetravalent element which is different from
`said first tetravalent element, trivalent element, pentavalent
`element or mixture thereof and having a crystallite size of
`0.5 micron or less.
`In accordance with the present invention, there is also
`provided a zeolite having the CHA crystal structure, a mole
`ratio greater than about 10 of silicon oxide to aluminum
`oxide, and having a crystallite size of 0.5 micron or less.
`Also provided in accordance with the present invention is
`a method of preparing a aluminosilicate crystalline material
`having the CHA crystal structure and a crystallite size of 0.5
`micron or less, said method comprising contacting under
`crystallization conditions an aluminum hydroxide gel dried 40
`to about 50 wt. % ~03 with a slight alkalinity and the
`ability to absorb C02 and solubilize rapidly in water, pre(cid:173)
`cipitated silica with a water content of about 5-15 wt. %, and
`a templating agent comprising a N,N,N-trimethyl-1-
`adamantammonium cation.
`This invention also provides a process for converting
`lower alcohols and other oxygenated hydrocarbons compris(cid:173)
`ing contacting said lower alcohol or other oxygenated
`hydrocarbon under conditions to produce liquid products
`with a catalyst comprising a zeolite having the CHA crystal 50
`structure, a mole ratio greater than about 10 of silicon oxide
`to aluminum oxide and having a crystallite size of about 0.5
`micron or less.
`Also provided by the present invention is an improved
`process for the reduction of oxides of nitrogen contained in 55
`a gas stream in the presence of oxygen wherein said process
`comprises contacting the gas stream \vith a zeolite, the
`improvement comprising using as the zeolite a zeolite
`having the CHA crystal structure, a mole ratio greater than
`about 10 of silicon oxide to aluminum oxide and having a 60
`crystallite size of 0.5 micron or less. The zeolite may contain
`a metal or metal ions (such as cobalt, copper or mixtures
`thereof) capable of catalyzing the reduction of the oxides of
`nitrogen, and may be conducted in the presence of a sto(cid:173)
`ichiometric excess of oxygen. In a preferred embodiment,
`the gas stream is the exhaust stream of an internal combus-
`tion engine.
`
`30
`
`35
`
`TABLE 1
`
`Reaction Mixture
`
`Typical
`
`20-50
`0.15-D.40
`0.10-D.35
`0.05-D.20
`10-25
`
`Preferred
`
`25-40
`0.25-DAO
`0.18-D.22
`0.12-D.18
`12-20
`
`Si02/Al2 03
`OH-/Si02
`Q/Si02
`}vf2 m/Si02
`H2 0/Si02
`
`45
`
`where Q is the SDA, M is alkali metal or alkaline earth
`metal, and n is the valence of M.
`In practice, SSZ-62 is prepared by a process comprising:
`(a) preparing an aqueous solution containing an aluminum
`hydroxide gel dried to about 50 wt. % Al2 0 3 \vith a
`slight alkalinity and the ability to absorb C02 and
`solubilize rapidly in water, precipitated silica with a
`water content of about 5-15 wt. % and a N,N,N(cid:173)
`trimethyl-1-adamantammonium cation having an
`anionic counterion which is not detrimental to the
`formation of SSZ-62;
`(b) maintaining the aqueous solution under conditions
`sufficient to form crystals of SSZ-62; and
`(c) recovering the crystals of SSZ-62.
`The source of silicon is precipitated silica with a water
`content of about 5-15 wt. %. An example of such a material
`is HiSil 233 available from PPG Industries, Inc.
`The source of aluminum is an aluminum hydroxide gel
`dried to about 50 wt. % Al20 3 . The gel has slight alkalinity
`and is able to absorb C02 . It is rapidly soluble in water. The
`aluminum hydroxide has a particle density of less than about
`1.0 g/cm 3
`, preferably less than about 0.9 g/cm3
`, more
`preferably less than about 0.8 g/cm3 and most preferably in
`the range of about 0.1 g/cm3 to about 0.8 g/cm3
`. An example
`of such a material is Reheis F-2000 available from Reheis
`65 Chemical Co.
`The aluminum hydroxide, as added to the reaction
`mixture, further has an average particle size of less than
`
`Umicore AG & Co. KG
`Exhibit 1004
`Page 2 of 5
`
`

`
`US 6,709,644 B2
`
`10
`
`3
`about 40 microns, preferably less than about 25 microns,
`more preferably less than about 15 microns, still more
`preferably less than about 10 microns, and most preferably
`within the range of about 0.1 to 10 microns, with preferably
`less than about 25% of the particulates having a particle size 5
`outside the range of about 0.1 to 40 microns. In a more
`preferred embodiment, less than about 25%, even more
`preferably less than 10% of the particles have a particle size
`outside the range of about 0.1 to about 25 microns.
`The aluminum hydroxide gel has a low alkali level before
`it is added to the reaction mixture. The gel contains less than
`about 0.12 wt. % and preferably less than 0.10 wt. % alkali.
`It is most preferred that the gel have an alkali content in the
`range of about 0.01 wt. % to about 0.10 wt. % where alkali
`may be one or more of the Group lA elements.
`Typically, an alkali metal hydroxide and/or an alkaline 15
`earth metal hydroxide, such as the hydroxide of sodium,
`potassium, lithium, cesium, rubidium, calcium, and
`magnesium, is used in the reaction mixture; however, this
`component can be omitted so long as the equivalent basicity
`is maintained. The templating agent may be used to provide 20
`hydroxide ion. Thus, it may be beneficial to ion exchange,
`for example, the halide for hydroxide ion, thereby reducing
`or eliminating the alkali metal hydroxide quantity required.
`The alkali metal cation or alkaline earth cation may be part
`of the as-synthesized crystalline oxide material, in order to 25
`balance valence electron charges therein.
`The SDA used to prepare SSZ-62 is a N,N,N-trimethyl-
`1-adamantammonium cation having the following structure:
`
`4
`separation techniques such as filtration. The crystals are
`water-washed and then dried, e.g., at 90° C. to 150° C. for
`from 8 to 24 hours, to obtain the as-synthesized SSZ-62
`zeolite crystals. The drying step can be performed at atmo(cid:173)
`spheric pressure or under vacuum.
`SSZ-62 as prepared has a mole ratio of silicon oxide to
`aluminum oxide of greater than 10. SSZ-62 can also be
`made with a mole ratio of silicon oxide to aluminum oxide
`of at least 30.
`The crystallite size of SSZ-62, as determined by 1EM, is
`less than 0.5 micron, preferably less than 0.1 micron.
`Crystalline SSZ-62 can be used as-synthesized, but pref(cid:173)
`erably will be thermally treated (calcined). Usually, it is
`desirable to remove the alkali metal cation by ion exchange
`and replace it \Vith hydrogen, ammonium, or any desired
`metal ion. The zeolite can be leached with chelating agents,
`e.g., EDTA or dilute acid solutions, to increase the silica to
`alumina mole ratio. The zeolite can also be steamed; steam(cid:173)
`ing helps stabilize the crystalline lattice to attack from acids.
`The zeolite can be used in intimate combination with
`hydrogenating components, such as tungsten, vanadium
`molybdenum, rhenium, nickel cobalt, chromium,
`manganese, or a noble metal, such as palladium or platinum,
`for those applications in which a hydrogenation(cid:173)
`dehydrogenation function is desired.
`Metals may also be introduced into the zeolite by replac-
`ing some of the cations in the zeolite with metal cations via
`standard ion exchange techniques (see, for example, U.S.
`Pat. No. 3,140,249 issued Jul. 7, 1964 to Plank et al.; U.S.
`Pat. No. 3,140,251 issued Jul. 7, 1964 to Plank et al.; and
`30 U.S. Pat. No. 3,140,253 issued Jul. 7, 1964 to Plank et al.).
`Typical replacing cations can include metal cations, e.g.,
`rare earth, Group lA, Group IIA and Group VIII metals, as
`well as their mixtures. Of the replacing metallic cations,
`cations of metals such as rare earth, Mn, Ca, Mg, Zn, Cd, Pt,
`35 Pd, Ni, Co, Ti, AI, Sn, and Fe are particularly preferred.
`The hydrogen, ammonium, and metal components can be
`ion-exchanged into the SSZ-62. The zeolite can also be
`impregnated with the metals, or, the metals can be physically
`and intimately admixed with the zeolite using standard
`40 methods known to the art.
`Typical ion-exchange techniques involve contacting the
`synthetic zeolite with a solution containing a salt of the
`desired replacing cation or cations. Although a wide variety
`of salts can be employed, chlorides and other halides,
`45 acetates, nitrates, and sulfates are particularly preferred. The
`zeolite is usually calcined prior to the ion-exchange proce(cid:173)
`dure to remove the organic matter present in the channels
`and on the surface, since this results in a more effective ion
`exchange. Representative ion exchange techniques are dis-
`50 closed in a wide variety of patents including U.S. Pat. No.
`3,140,249 issued on Jul. 7, 1964 to Plank et al.; U.S. Pat. No.
`3,140,251 issued on Jul. 7, 1964 to Plank et al.; and U.S. Pat.
`No. 3,140,253 issued on Jul. 7, 1964 to Plank et al.
`Following contact with the salt solution of the desired
`55 replacing cation, the zeolite is typically washed with water
`and dried at temperatures ranging from 65° C. to about 200°
`C. After washing, the zeolite can be calcined in air or inert
`gas at temperatures ranging from about 200° C. to about
`800° C. for periods of time ranging from 1 to 48 hours, or
`60 more, to produce a catalytically active product especially
`useful in hydrocarbon conversion processes.
`Regardless of the cations present in the synthesized form
`of SSZ-62, the spatial arrangement of the atoms which form
`the basic crystal lattice of the zeolite remains essentially
`65 unchanged.
`SSZ-62 can be formed into a wide variety of physical
`shapes. Generally speaking, the zeolite can be in the form of
`
`CH3
`
`I @
`
`CH3-r\-CH3
`
`The anion (X-) associated with the cation may be any anion
`which is not detrimental to the formation of the zeolite.
`Representative anions include halogen, e.g., fluoride,
`chloride, bromide and iodide, hydroxide, acetate, sulfate,
`tetrafiuoroborate, carboxylate, and the like. Hydroxide is the
`most preferred anion.
`The reaction mixture is maintained at an elevated tem(cid:173)
`perature until the crystals of the SSZ-62 zeolite are formed.
`The hydrothermal crystallization is usually conducted under
`autogenous pressure, at a temperature between 100° C. and
`200° C., preferably between 135° C. and 160° C. The
`crystallization period is typically greater than 1 day and
`preferably from about 3 days to about 20 days.
`Preferably, the zeolite is prepared using mild stirring or
`agitation.
`During the hydrothermal crystallization step, the SSZ-62
`crystals can be allowed to nucleate spontaneously from the
`reaction mixture. The use of SSZ-62 crystals as seed mate(cid:173)
`rial can be advantageous in decreasing the time necessary
`for complete crystallization to occur. In addition, seeding
`can lead to an increased purity of the product obtained by
`promoting the nucleation and/or formation of SSZ-62 over
`any undesired phases. When used as seeds, SSZ-62 crystals
`are added in an amount between 0.1 and 10% of the weight
`of silica used in the reaction mixture.
`Once the zeolite crystals have formed, the solid product is
`separated from the reaction mixture by standard mechanical
`
`Umicore AG & Co. KG
`Exhibit 1004
`Page 3 of 5
`
`

`
`US 6,709,644 B2
`
`6
`Typically, the SSZ-62 is used as a component in a membrane
`that is used to separate the gasses.
`
`EXAMPLES
`
`The following examples demonstrate but do not limit the
`present invention.
`
`Example 1
`
`Synthesis of SSZ-62
`In a Teflon cup for a Parr 23 ml stainless steel reactor, a
`solution is formed by adding 7 grams of a 0.61 M solution
`of N ,N ,N- trimethy 1-1-adamantammonium hydroxide
`(prepared as described in U.S. Pat. No. 4,544,538, issued
`Oct. 1, 1985 to Zones, the disclosure of which is incorpo(cid:173)
`rated by reference in its entirety), 0.18 gram of solid NaOH,
`and 0.112 gram of Reheis F-2000 aluminum hydroxide gel
`(dried, 50-53 wt. % Al2 0 3 ). After a clear solution is
`obtained, 1.63 grams of HiSil 233 silica source is stirred in.
`The reactor is closed and mounted onto a spit operating
`within a Blue M convection oven. The spit is rotated at 45
`RPM and the reaction mixture is heated at 160° C. for six
`days. Analysis by SEM shows that a product, with very
`small crystals, seems to have formed. The XRD powder data
`for this product shows the product to have the chabazite
`structure v.rith noticeable line broadening over conventional
`SSZ-13 (also with the chabazite structure). Analysis by TEM
`shows a large, homogeneous distribution of crystals aver(cid:173)
`aging 0.05 to 0.1 micron on edge. Typical SSZ-13 products
`have been 0.5 to 1.0 micron in length (the crystals are close
`to cubic in morphology). The silica/alumina mole ratio of
`the SSZ-62 product is 22.
`
`Comparative Examples
`
`Some comparative examples are also run using the pro-
`cedure of Example 1. Using greater or lesser mole ratios of
`water/silica (ratios of 44, 8, 3.5 as compared v.rith 16 above)
`results in products \vith larger crystals. Replacing the HiSil
`233 silica source with Cabosil M5 fumed silica available
`from Cabot Corporation al<>o produces larger crystals.
`
`Example 2
`
`10
`
`35
`
`40
`
`5
`a powder, a granule, or a molded product, such as extrudate
`having a particle size sufficient to pass through a 2-mesh
`(Tyler) screen and be retained on a 400-mesh (Tyler) screen.
`In cases where the catalyst is molded, such as by extrusion
`with an organic binder, the aluminosilicate can be extruded 5
`before drying, or, dried or partially dried and then extruded.
`SSZ-62 can be composited with other materials resistant
`to the temperatures and other conditions employed in
`organic conversion processes. Such matrix materials include
`active and inactive materials and synthetic or naturally
`occurring zeolites as well as inorganic materials such as
`clays, silica and metal oxides. Examples of such materials
`and the manner in which they can be used are disclosed in
`U.S. Pat. No. 4,910,006, issued May 20, 1990 to Zoneset al.,
`and U.S. Pat. No. 5,316,753, issued May 31, 1994 to
`Nakagawa, both of which are incorporated by reference 15
`herein in their entirety.
`Condensation of Alcohols
`SSZ-62 can be used to condense lower aliphatic alcohols
`having 1 to 10 carbon atoms to a gasoline boiling point
`hydrocarbon product comprising mixed aliphatic and aro- 20
`matic hydrocarbon. The process disclosed in U.S. Pat. No.
`3,894,107, i<>sued Jul. 8, 1975 to Butter et al., describes the
`process conditions used in this process, which patent is
`incorporated totally herein by reference.
`The catalyst may be in the hydrogen form or may be base 25
`exchanged or impregnated to contain ammonium or a metal
`cation complement, preferably in the range of from about
`0.05 to 5% by weight. The metal cations that may be present
`include any of the metals of the Groups I through VIII of the
`Periodic Table. However, in the case of Group IA metals, the 30
`cation content should in no case be so large as to effectively
`inactivate the catalyst, nor should the exchange be such as
`to eliminate all acidity. There may be other processes
`involving treatment of oxygenated substrates where a basic
`catalyst is desired.
`Preparing Dimethylamine
`SSZ-62 can also be used as a catalyst to prepare dim(cid:173)
`ethylamine. Dimethylamine is generally prepared in indus(cid:173)
`trial quantities by continuous reaction of methanol (and/or
`dimethylether) and ammonia in the presence of a silica(cid:173)
`alumina catalyst. The reactants are typically combined in the
`vapor phase, at temperatures in the range of 300° C. to 500°
`C., and at elevated pressures. Such a process is disclosed in
`U.S. Pat. No. 4,737,592, issued Apr. 12, 1988 to Abrams et
`al., which is incorporated by reference in its entirety.
`The catalyst, i.e., SSZ-62, is used in its acid form. Acid
`forms of zeolites can be prepared by a variety of techniques,
`such as those described above. Preferably, the SSZ-62 used
`to prepare dimethylamine will be in the hydrogen form, or
`have an alkali or alkaline earth metal, such as Na, K, Rb, or 50
`CS, ion-exchanged into it.
`The process of the present invention involves reacting
`methanol and/or dimethylether and ammonia in amounts
`sufficient to provide a carbon/nitrogen (C/N) ratio from
`about 0.2 to about 1.5, preferably about 0.5 to about 1.2. The 55
`reaction is conducted at a temperature from about 250° C. to
`about 450° C., preferably about 300° C. to about 400° C.
`Reaction pressures can vary from about 7-7000 kPa
`(1-1000 psi), preferably about 70-3000kPa (10-500 psi). A
`methanol and/or dimethylether space time of about 0.01-80 60
`hours, preferably 0.10-1.5 hours, is typically used. This
`space time is calculated as the mass of catalyst divided by
`the mass flow rate of methanol!dimethylether introduced
`into the reactor.
`Gas Separation
`SSZ-62 can also be used to separate gasses. For example,
`it can be used to separate carbon dioxide from natural gas.
`
`Calcination of SSZ-62
`The material from Example 1 is calcined in the following
`manner. A thin bed of material is heated in a muffie furnace
`45 from room temperature to 120° C. at a rate of 1 o C. per
`minute and held at 120° C. for three hours. The temperature
`is then ramped up to 540° C. at the same rate and held at this
`temperature for 5 hours, after which it is increased to 594°
`C. and held there for another 5 hours. A 50!50 mixture of air
`and nitrogen is passed over the zeolite at a rate of 20
`standard cubic feet per minute during heating.
`The product of the calcination is analyzed with nitrogen
`using a Micrometries Digisorb instrument. The product has
`a micropore volume of 0.28 cc/g and a surface area of near
`700m2/g.
`
`Example 3
`
`NH4 Exchange
`Ion exchange of calcined SSZ-62 material (prepared in
`Example 2) is performed using NH4 N0 3 to convert the
`zeolite from its Na+ form to the NH4 +form, and, ultimately,
`the H+ form. Typically, the same mass ofNH4 N03 as zeolite
`is slurried in water at a ratio of 25-50:1 water to zeolite. The
`exchange solution is heated at 95° C. for 2 hours and then
`65 filtered. This procedure can be repeated up to three times.
`Following the final exchange, the zeolite is washed several
`times with water and dried. This NH4 + form of SSZ-62 can
`
`Umicore AG & Co. KG
`Exhibit 1004
`Page 4 of 5
`
`

`
`US 6,709,644 B2
`
`7
`then be converted to the H+ form by calcination (as
`described in Example 9) to 540° C.
`
`Example 4
`Use of SSZ-62 To Convert Methanol
`The zeolite of Example 3, after heating to 540° C. to
`convert NH4 + to H+, is pelletized at 2-3 KPSI, then crushed
`and meshed to 20-40. 0.50 Gram is loaded into a % inch
`stainless steel reactor tube with alundum on the side of the
`zeolite bed where the feed is introduced. The reactor is
`heated in a Lindberg furnace to 1000° F. for 3 hours in air,
`and then the temperature is reduced to 330° C. in a stream
`of nitrogen at 20 cc/min. A 22.1% methanol feed (22.1 g
`methanol/77.9 g water) is introduced into the reactor at a rate
`of 1.31 cc/hr.
`The catalyst gives greater than 90% selectivity for C2-C4
`ole fins and does not show methanol breakthrough for greater
`than 15 hours. Prior art catalysts with larger crystallite sizes
`than SSZ-62 (like SSZ-13 with a crystallite size of about 1.2
`microns and a silica/alumina mole ratio of about 9 or 18)
`show breakthrough at about 5 hours on stream under these
`conditions. The smaller crystallite SSZ-62 gives superior
`performance in this application.
`What is claimed is:
`1. A zeolite having the CHA crystal structure, a mole ratio
`greater than about 10 of an oxide of a first tetravalent
`element to an oxide of a second tetravalent element which is
`different from said first tetravalent element, trivalent
`element, pentavalent element or mixture thereof and having
`a crystallite size of 0.5 micron or less.
`2. A zeolite having the CHA crystal structure, a mole ratio
`greater than about 10 of silicon oxide to aluminum oxide,
`and having a crystallite size of 0.5 micron or less.
`3. A zeolite according to claim 2 wherein the mole ratio
`of silicon oxide to aluminum oxide is at least 30.
`4. A zeolite according to claim 2 wherein the crystallite
`size is 0.1 micron or less.
`5. A zeolite according to claim 1 wherein said zeolite is
`predominantly in the hydrogen form.
`6. A zeolite according to claim 1 wherein said zeolite is
`substantially free of acidity.
`7. A method of preparing an aluminosilicate crvstalline
`~ate rial havi~g the CHA crystal structure and a c;ystallite
`~1ze of 0.5 m1cron or less, said method comprising contact(cid:173)
`mg under crystallization conditions an aluminum hydroxide
`gel dried to about 50 wt. % Al 2 0 3 , precipitated silica with a
`water ~~ntent of about 5-15 wt. % and a templating agent
`~ompnsmg a N,N,N-trimethyl-1-adamantammonium cat(cid:173)
`Ion.
`
`5
`
`10
`
`15
`
`8
`. 8. The met~od of claim 7 wherein the aluminum hydrox(cid:173)
`Ide has a partlcle density of less than about 1.0 gicm3
`.
`9. The method of claim 7 wherein the aluminum hvdrox(cid:173)
`ide has a particle size of less than about 40 microns:
`10. The method of claim 7 wherein the aluminum hydrox(cid:173)
`ide has an alkali content of less than about 0.12 wt. %.
`11. A process for converting lower alcohols and other
`oxygenated hydrocarbons comprising contacting said lower
`alcohol or other oxygenated hydrocarbon under conditions
`to p_roduce. liquid products with a catalyst comprising a
`zeohte havmg the CHA crystal structure, a mole ratio greater
`than abou.t 10 ?f silicon oxide to aluminum oxide and having
`a crystallite s1ze of about 0.5 micron or less.
`12. The process of claim 11 wherein the lower alcohol is
`methanol.
`13. In a process for the reduction of oxides of nitrogen
`contained in a gas stream in the presence of oxygen wherein
`said process comprises contacting the gas stream with a
`zeolite, the improvement comprising using as the zeolite a
`zeolite having the CHAcrystal structure, a mole ratio greater
`than about 10 of silicon oxide to aluminum oxide and having
`a crystallite size of 0.5 micron or less.
`14. The process of claim 13 wherein said zeolite contains
`a metal or metal ions capable of catalyzing the reduction of
`the oxides of nitrogen.
`15. The p.rocess of claim 14 wherein the metal is copper,
`cobalt or m1xtures thereof.
`16. The process of claim 14 wherein the gas stream is the
`exhaust stream of an internal combustion engine.
`17: A process for prod~cing dimethylamine comprising
`reactmg methanol and/or d1methvl ether and ammonia in the
`gase?us p~ase in the presence ~f a catalyst comprising a
`zeolite havmg the CHAcrystal structure, a mole ratio greater
`than about 10 of silicon oxide to aluminum oxide and having
`a crystallite size of 0.5 micron or less.
`18. The process of claim 17 wherein the methanol and/or
`dimethylether and ammonia are present in amounts suffi(cid:173)
`cient to provide a carbon/nitrogen ratio from about 0.2 to
`about 1.5.
`19. The process of claim 17 conducted at a temperature of
`40 from about 250° C. to about 450° C.
`20. In a process for separating gasses using a membrane
`containing a zeolite, the improvement comprising using a
`zeolite having the CHA crystal structure, a mole ratio greater
`than about 10 of silicon oxide to aluminum oxide and having
`45 a crystallite size of 0.5 micron or less.
`21. The process of claim 20 wherein the process separates
`carbon dioxide from natural gas.
`* * * * *
`
`20
`
`25
`
`30
`
`35
`
`Umicore AG & Co. KG
`Exhibit 1004
`Page 5 of 5