144 results about "Chabazite" patented technology

The synthesis of a crystalline material, in particular, a high silica zeolite, comprising a chabazite-type framework molecular sieve is conducted in the presence of an organic directing agent having the formula:

[R¹R²R³N—R⁴]⁺Q⁻

wherein R¹ and R² are independently selected from hydrocarbyl groups and hydroxy-substituted hydrocarbyl groups having from 1 to 3 carbon atoms, provided that R¹ and R² may be joined to form a nitrogen-containing heterocyclic structure, R³ is an alkyl group having 2 to 4 carbon atoms and R⁴ is selected from a 4- to 8-membered cycloalkyl group, optionally, substituted by 1 to 3 alkyl groups each having from 1 to 3 carbon atoms; and a 4- to 8-membered heterocyclic group having from 1 to 3 heteroatoms, said heterocyclic group being, optionally, substituted by 1 to 3 alkyl groups each having from 1 to 3 carbon atoms and the or each heteroatom in said heterocyclic group being selected from the group consisting of O, N, and S, or R³ and R⁴ are hydrocarbyl groups having from 1 to 3 carbon atoms joined to form a nitrogen-containing heterocyclic structure; and Q⁻ is a anion.

The synthesis of a crystalline aluminophosphate or silicoaluminophosphate molecular sieve having a chabazite-type framework type is conducted in the presence of an organic directing agent having the formula (I)

[R¹R²R³N—R⁴]⁺X⁻  (I)

wherein R¹, R² and R³ are independently selected from the group consisting of alkyl groups having from 1 to 3 carbon atoms and hydroxyalkyl groups having from 1 to 3 carbon atoms; R⁴ is selected from the group consisting of 4- to 8-membered cycloalkyl groups, optionally substituted by 1 to 3 alkyl groups having from 1 to 3 carbon atoms; 4- to 8-membered heterocyclic groups having from 1 to 3 heteroatoms, said heterocyclic groups being optionally substituted by 1 to 3 alkyl groups having from 1 to 3 carbon atoms and the heteroatoms in said heterocyclic groups being selected from the group consisting of O, N, and S; and aromatic groups optionally substituted by 1 to 3 alkyl groups, said alkyl groups having from 1 to 3 carbon atoms; and X⁻ is an anion.

A cementitious composition for cementing an oil or gas well and which exhibits, when cured, increased flexural strength and a flexural strength to compressive strength ratio between from about 0.29 to about 0.80, contains a hydraulically-active cementitious material, such as Portland cement, and substantially spherical zeolite. Representative zeolites include natrolite, heulandite, analcime, chabazite, stilbite, and clinoptilolite. The weight percent of zeolite in the cement composition is generally less than or equal to 15 percent. In practice, a well bore may be cemented by pumping the activated slurry and pumping it within the well bore to a pre-selected location and allowing it to solidify.

A method of adsorbing mercury includes the use of silver nanodots formed on chabazite as a sorbent. The silver nanodots may be formed on chabazite by ion-exchange followed by activation.

There is disclosed a method to synthesize microporous crystalline material comprising a metal containing chabazite having a crystal size greater than 0.5 microns and a silica-to-alumina ratio (SAR) between 5 and 15, wherein the method is carried out without the use of an organic structural directing agent and without requiring calcination. There is also disclosed a large crystal organic free chabazite made according to the disclosed method. In addition, there are disclosed methods of using the disclosed crystalline material, such as in the selective catalytic reduction of NO_x in exhaust gases.

The synthesis of a crystalline material, in particular a high silica zeolite, having a chabazite-type framework is aided by the addition to the synthesis mixture of seeds of an AEI framework-type material. The chabazite-type product has a relatively small crystal size and exhibits activity and selectivity in the conversion of methanol to lower olefins, especially ethylene and propylene.

A crystalline material substantially free of framework phosphorus and comprising a CHA framework type molecular sieve with stacking faults or at least one intergrown phase of a CHA framework type molecular sieve and an AEI framework type molecular sieve, wherein said material, in its calcined, anhydrous form, has a composition involving the molar relationship:

(n)X₂O₃:YO₂,

wherein X is a trivalent element; Y is a tetravalent element; and n is from 0 to about 0.5. The material exhibits activity and selectivity in the conversion of methanol to lower olefins, especially ethylene and propylene.

A method is taught for capturing organoleptic odor. Where a functional additive has odors from a plurality of organolepic sources, and is blended with an odor control agent and a resin to produce a blend, where the blend exhibits at least a 5% reduction in odor based on a standardized odor test SAE-J1351. The odor control agent is selected from the group but not limited to: nepheline syenite, silica gel, hydrogels, hard and soft clays, bentonite, clinoptilolite, hectorite, cationic exchanged clinoptilolites, cerium, cesium, chabazite, faujasite, gmelinite, brewsterite, calcium silicate, hydrotalcites, zinc or magnesium aluminum hydroxy carbonates, zinc oxide, zinc hydroxide, zinc carbonate, calcium oxide, calcium hydroxide, calcium carbonate, potassium meta phosphate, silver oxide, magnesium hydroxide, magnesium oxide, copper oxide, ferric and ferrous oxides, sorbitol, glucitol, mannitol, glucose, dextrose, dextrin, allophanes, silica, sodalite, silicon oxide, aluminum oxide, natural zeolites, manganese dioxide, nano zinc oxide and nano titanium and combination thereof.

A catalyst composition includes a heterobimetallic zeolite characterized by a chabazite structure loaded with copper ions and at least one trivalent metal ion other than Al³⁺. The catalyst composition decreases NO_x emissions in diesel exhaust and is suitable for operation in a catalytic converter.

In a method of synthesizing a mostly CHA-type silicoaluminophosphate sieve, a reaction mixture comprises sources of water, silicon, aluminum, phosphorus, and a template. In one aspect, the inorganic phosphorus and silicon sources are first combined to form a primary mixture that is aged. Then, the aluminum source is added, followed optionally by any organic phosphorus source, and then the template, to form the synthesis mixture. After heating at <10° C./hr to induce crystallization, in this aspect, both the crystallized sieve has an average crystal size ≦1.5 μm and/or is recovered in a yield of ≧10.0 wt %. In another aspect, when the synthesis mixture Si/Al₂ ratio is <0.33, crystallization is induced. Advantageously, the sieve so crystallized has a template efficiency of ≧0.5 and/or is recovered in a yield of ≧10.0 wt %. The molecular sieve from both aspects can be used in a hydrocarbon (oxygenates-to-olefins) conversion process.

Problems on catalyst production and catalyst performance with respect to conventional 8-oxygen-membered ring micropore-containing crystalline silicoaluminophosphate molecular sieves as non-equilibrium methylamine synthesis catalysts, are resolved. A chabazite type crystalline silicoaluminophosphate molecular sieve having high purity and high crystallinity and having, on a crystal grain surface, an amorphous oxide layer whose Si/Al atomic ratio is greater than that of the whole crystal grain can be stably produced with high yield with the use of a small amount of structure directing agents by the present method characterized in that hydrothermal treatment conducted in the production of 8-oxygen-membered ring micropore-containing crystalline silicoaluminophosphate sieves is controlled under specified treating conditions. The thickness and composition of the amorphous oxide layer, which exert marked influence on the yield of dimethylamine synthesis, can be easily controlled and reproduced under the conditions of catalyst synthesis according to the invention. Thus, the catalyst of high performance can be stably supplied by the present invention at a low cost with reduced output of waste.

An iron-zeolite chabazite (CHA) catalyst is provided as an SCR catalyst for reducing nitrogen oxides (NO_x) from vehicle engine exhausts. The catalyst is formed by incorporating iron during synthesis of the chabazite zeolite, which eliminates the need for a post-synthesis ion-exchange step and which results in the incorporation of iron into the (CHA) zeolite crystal lattice structure. The resulting catalyst exhibits good high temperature activity at temperatures greater than 550° C. and exhibits good thermal stability.

Disclosed are processes for the preparation of copper containing molecular sieves with the CHA structure wherein the copper is exchanged into the Na+-form of the Chabazite, using a liquid copper solution wherein the concentration of copper is in the range of about 0.001 to about 0.4 molar. Also described are copper containing molecular sieves with the CHA structure, catalysts incorporating molecular sieves, systems and methods for their use.

Cu-exchanged zeolite catalysts with a chabazite structure containing selected concentrations of alkali ions or alkaline-earth ions and a lower concentration of (Cu) ions are described and a sequential process for making. Catalysts of the present invention reduce light-off temperatures providing enhanced low-temperature conversion of NOx gases. Catalysts of the present invention also exhibit high selectivity values compared to conventional NOx reduction catalysts.

The invention provides a method for synthesizing a zeolite molecular sieve with a chabasite structure. The preparation method includes the step of adding organic weak base to obtain the aluminosilicate zeolite molecular sieve with the chabasite structure without adding organic template agents or chabasite seed crystals in chabasite synthesizing reaction under hydrothermal conditions. The molar ratio of framework silicon-aluminum atoms ranges from 4 to 40, and reaction raw materials are prepared according to the molar ratio of Na2O:K2O:the organic weak base Al2O3:SiO2:H2O=(1-20):(2-30):(0.05-8.0):1:(8-80):(150-800). According to the method, the zeolite molecular sieve with the chabasite structure can be stably synthesized without the template agents, fluorinated compounds and the seed crystals.

In a method of synthesizing a silicoaluminophosphate or aluminophosphate molecular sieve comprising a CHA framework-type material, a synthesis mixture is provided comprising a source of aluminum, a source of phosphorus, optionally a source of silicon and at least one organic template of formula (I):

[R¹R²R³R⁴N]⁺ X⁻  (I)

wherein each of R¹, R², R³, and R⁴ is independently an acyclic alkyl group having at least one carbon atom, the total number of carbon atoms in said alkyl groups R¹, R², R³, and R⁴ is greater than 8 but less than 16, and X⁻ is an anion. The synthesis mixture can then be crystallized to produce the desired molecular sieve.

The present invention relates to zeolitic compositions of at least one A, X, Y zeolite and/or chabazite and at least one clinoptilolite type of zeolite.

These zeolitic compositions can be used in adsorption methods for removing H₂O and/or CO₂ and/or H₂S present in gas or liquid mixtures, particularly for purifying natural gas, acid gases, alcohols and mercaptans.

The present invention relates to a chabazite zeolite membrane with a controlled pore size and a production method thereof, wherein the sizes of pore space and pore mouth of the chabazite zeolite membrane are finely controlled through chemical vapor deposition. Through the chemical vapor deposition, defects present in the chabazite zeolite membrane are eliminated, and the pore size is effectively controlled. Thus, unlike hydrophilic membranes showing excellent CO₂/N₂ separation performance under a dry condition, the chabazite zeolite membrane with a controlled pore size according to the present invention has a hydrophobic surface, and thus can maintain excellent CO₂/N₂ separation performance even under a wet condition. Accordingly, the chabazite zeolite membrane of the present invention can effectively capture carbon dioxide from nitrogen under various environmental conditions.