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.

The present invention relates to a process for preparing zeolite crystals continuously, comprising the continuous introduction of a composition capable of generating zeolite crystals into at least one crystallization reaction zone subjected to stirring means, giving said composition a flow characterized by a relative Reynolds number Re.sub.r of between 40 and 50 000, and the continuous recovery of the crystals formed according to a flow characterized by a net Reynolds number Re.sub.n of between 1 and 1500.

A method for synthesizing a supported molecular sieve membrane by microwaves includes the steps of aging, heating and synthesizing. The aging step is to make a support in contact with a synthetic liquid at 25 C. to 70 C. for 10 hours to 24 hours; the heating step is to raise a temperature of an aged system from an aging temperature to a synthesis temperature within 1 minute to 10 minutes; and the synthesizing step is to synthesize at 80 C. to 120 C. for 2 minutes to 15 minutes. The steps of heating and synthesizing are powered by microwaves.

A method for synthesizing a supported molecular sieve membrane by microwaves includes the steps of aging, heating and synthesizing. The aging step is to make a support in contact with a synthetic liquid at 25 C. to 70 C. for 10 hours to 24 hours; the heating step is to raise a temperature of an aged system from an aging temperature to a synthesis temperature within 1 minute to 10 minutes; and the synthesizing step is to synthesize at 80 C. to 120 C. for 2 minutes to 15 minutes. The steps of heating and synthesizing are powered by microwaves.

A hydrocarbon adsorbent having high hydrocarbon adsorbing properties even after exposed to a high temperature/high humidity reducing atmosphere, includes a FAU type zeolite having in ESR measurement a spin concentration of a least 1.010{circumflex over ()}19 (spins/g) and a ratio of a peak intensity at a magnetic field of at least 260 mT and at most 270 mT to a peak intensity at a magnetic field of at least 300 mT and at most 320 mT of at least 0.25 and at most 0.50 and containing bivalent copper. The hydrocarbon adsorbent may be used for a method for adsorbing hydrocarbons to be exposed to a high temperature/high humidity environment, and may be used particularly for a method for adsorbing hydrocarbons in an exhaust gas of an internal combustion engine, such as an automobile exhaust gas.

A hydrocarbon adsorbent having high hydrocarbon adsorbing properties even after exposed to a high temperature/high humidity reducing atmosphere, includes a FAU type zeolite having in ESR measurement a spin concentration of a least 1.010{circumflex over ()}19 (spins/g) and a ratio of a peak intensity at a magnetic field of at least 260 mT and at most 270 mT to a peak intensity at a magnetic field of at least 300 mT and at most 320 mT of at least 0.25 and at most 0.50 and containing bivalent copper. The hydrocarbon adsorbent may be used for a method for adsorbing hydrocarbons to be exposed to a high temperature/high humidity environment, and may be used particularly for a method for adsorbing hydrocarbons in an exhaust gas of an internal combustion engine, such as an automobile exhaust gas.

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.

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.