A system for recovering rare earth elements from coal ash includes a leaching reactor, an ash dryer downstream of the leaching reactor, and a roaster downstream of the ash dryer that is cooperatively connected to both the leaching reactor and the ash dryer. Coal ash is mixed with an acid stream such that rare earth elements present in the coal ash are dissolved in the acid stream, thereby creating (i) a leachate containing the rare earth elements and (ii) leached ash. The leachate is heated to obtain acid vapor and an acid-soluble rare earth concentrate. Mixing of the coal ash with the acid stream can occur in a leaching reactor and heating of the leachate can occur in a roaster. The acid-soluble rare earth concentrate can be fed to a hydrometallurgical process to separate and purify the rare earth elements.

Methods and systems for production of consistently-sized BEA zeolite nano-crystals, the method including mixing an emulsion, the emulsion comprising a surfactant and an organic solvent; heating the emulsion; mixing a zeolite solution, the zeolite solution comprising a silicon-containing compound and an aluminum-containing compound; heating the zeolite solution; adding the emulsion to the zeolite solution drop-wise over time to create an zeolite emulsion solution mixture; heating the zeolite emulsion solution mixture; and precipitating the consistently-sized BEA zeolite nano-crystals.

Methods and systems for production of consistently-sized BEA zeolite nano-crystals, the method including mixing an emulsion, the emulsion comprising a surfactant and an organic solvent; heating the emulsion; mixing a zeolite solution, the zeolite solution comprising a silicon-containing compound and an aluminum-containing compound; heating the zeolite solution; adding the emulsion to the zeolite solution drop-wise over time to create an zeolite emulsion solution mixture; heating the zeolite emulsion solution mixture; and precipitating the consistently-sized BEA zeolite nano-crystals.

Provided are a hydrocarbon adsorbent, an exhaust gas purifying catalyst, and an exhaust gas purifying system, which are capable of adsorbing hydrocarbons, storing the adsorbed hydrocarbons up to a relatively high temperature, and desorbing the adsorbed and stored hydrocarbons at a relatively high temperature.

The hydrocarbon adsorbent contains a multipore zeolite containing, outside the zeolite framework, at least one metal selected from the group consisting of transition metals belonging to Groups 3 to 12 in the periodic table, amphoteric metals belonging to Groups 13 and 14 in the periodic table, alkali metals, and alkaline earth metals; and has a content ratio of the metal of 9% by mass or less relative to the multipore zeolite containing the metal.

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.

The present disclosure generally provides catalysts, catalytic articles and catalyst systems including such catalytic articles. In particular, the catalyst composition includes a zeolite having a chabazite (CHA) crystal structure ion-exchanged with iron and copper. Methods of making and using the catalyst composition are also provided, as well as emission treatment systems containing a catalyst article coated with the catalyst composition. The catalyst article present in such emission treatment systems is useful to catalyze the reduction of nitrogen oxides in gas exhaust in the presence of a reductant.

The present disclosure generally provides catalysts, catalytic articles and catalyst systems including such catalytic articles. In particular, the catalyst composition includes a zeolite having a chabazite (CHA) crystal structure ion-exchanged with iron and copper. Methods of making and using the catalyst composition are also provided, as well as emission treatment systems containing a catalyst article coated with the catalyst composition. The catalyst article present in such emission treatment systems is useful to catalyze the reduction of nitrogen oxides in gas exhaust in the presence of a reductant.

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.