The invention concerns a process for preparing a copper-comprising SAPO material with AFX structure, comprising at least the steps of mixing, in an aqueous medium, at least one aluminum source, at least one silicon source, at least one copper source, at least one phosphorus source, a TETA complexing agent and a TMHD structuring agent, in order to obtain a gel, and hydrothermal treatment of said gel with a shear rate of less than 50 s.sup.−1 in order to obtain crystallization of said copper-comprising SAPO material with AFX structure.

A process of making a silica-alumina composition having improved properties is provided. The process includes (a) mixing an aqueous solution of a silicon compound and an aqueous solution of an aluminum compound and an acid, while maintaining a pH of the mixed solution in a range of 1 to 3, and obtaining an acidified silica-alumina sol; (b) adding an aqueous solution of a base precipitating agent to the acidified silica-alumina sol to a final pH in a range of 5 to 8, and co-precipitating a silica-alumina slurry, wherein the base precipitating agent is selected from ammonium carbonate, ammonium bicarbonate, and any combination thereof; (c) optionally, hydrothermally aging the silica-alumina slurry to form a hydrothermally aged silica-alumina slurry; and (d) recovering a precipitate solid from the silica-alumina slurry or the hydrothermally aged silica-alumina slurry, wherein the precipitate solid comprises the silica-alumina composition.

The present invention provides a catalyst for aromatization of a long-carbon chain alkane and a preparation method thereof. In the present invention, a molecular sieve containing a BEA structure is taken as an active component and mixed with a carrier, and then the mixture is formed, dried and calcined to obtain the catalyst for aromatization of a long-carbon chain alkane. The active component is prepared by taking a Naβ molecular sieve as a raw material and modifying through the following steps of: first obtaining an Hβ molecular sieve through ammonium ion-exchange, and then conducting dealumination and silicon insertion treatment of the Hβ molecular sieve through first hydrothermal treatment; forming a mesoporous structure in a molecular sieve framework through second hydrothermal treatment; reducing the acidity of the catalyst by potassium ion exchange, and finally using metal modification to improve the capability of the catalyst for catalyzing the aromatization of the long-carbon chain alkane and enhancing the toluene selectivity. The catalyst provided by the present invention shows high stability in the aromatization of the long-chain alkane and has a service life up to 170 h or above and aromatic hydrocarbon selectivity up to 80%, and the selectivity to toluene in aromatic hydrocarbon products can reach 85.5%.

The present invention provides a catalyst for aromatization of a long-carbon chain alkane and a preparation method thereof. In the present invention, a molecular sieve containing a BEA structure is taken as an active component and mixed with a carrier, and then the mixture is formed, dried and calcined to obtain the catalyst for aromatization of a long-carbon chain alkane. The active component is prepared by taking a Naβ molecular sieve as a raw material and modifying through the following steps of: first obtaining an Hβ molecular sieve through ammonium ion-exchange, and then conducting dealumination and silicon insertion treatment of the Hβ molecular sieve through first hydrothermal treatment; forming a mesoporous structure in a molecular sieve framework through second hydrothermal treatment; reducing the acidity of the catalyst by potassium ion exchange, and finally using metal modification to improve the capability of the catalyst for catalyzing the aromatization of the long-carbon chain alkane and enhancing the toluene selectivity. The catalyst provided by the present invention shows high stability in the aromatization of the long-chain alkane and has a service life up to 170 h or above and aromatic hydrocarbon selectivity up to 80%, and the selectivity to toluene in aromatic hydrocarbon products can reach 85.5%.

Compositions of manganese accumulating plants.

Compositions of manganese accumulating plants.

The present application relates to a method for synthesizing nanozeolite Y crystals, nanozeolite Y crystals obtainable by said method, and the use of the synthesized nanozeolite Y crystals in cracking hydrocarbons, as molecular sieves or as ion-exchangers.

The present application relates to a method for synthesizing nanozeolite Y crystals, nanozeolite Y crystals obtainable by said method, and the use of the synthesized nanozeolite Y crystals in cracking hydrocarbons, as molecular sieves or as ion-exchangers.

Improved alkylation catalysts, alkylation methods, and methods of making alkylation catalysts are described. The alkylation method comprises reaction over a solid acid, zeolite-based catalyst and can be conducted for relatively long periods at steady state conditions. The alkylation catalyst comprises a crystalline zeolite structure, a Si/Al molar ratio of 20 or less, less than 0.5 weight percent alkali metals, and further having a characteristic catalyst life property. Some catalysts may contain rare earth elements in the range of 10 to 35 wt %. One method of making a catalyst includes a calcination step following exchange of the rare earth element(s) conducted at a temperature of at least 575° C. to stabilize the resulting structure followed by an deammoniation treatment. An improved method of deammoniation uses low temperature oxidation.

Improved alkylation catalysts, alkylation methods, and methods of making alkylation catalysts are described. The alkylation method comprises reaction over a solid acid, zeolite-based catalyst and can be conducted for relatively long periods at steady state conditions. The alkylation catalyst comprises a crystalline zeolite structure, a Si/Al molar ratio of 20 or less, less than 0.5 weight percent alkali metals, and further having a characteristic catalyst life property. Some catalysts may contain rare earth elements in the range of 10 to 35 wt %. One method of making a catalyst includes a calcination step following exchange of the rare earth element(s) conducted at a temperature of at least 575° C. to stabilize the resulting structure followed by an deammoniation treatment. An improved method of deammoniation uses low temperature oxidation.