The present invention relates to a process for preparing zeolite crystals having a multimodal particle size distribution, and the sizes of which are between 0.02 μm and 20 μm, said process comprising a first introduction of one or more seeding agents into the tubular reactor or upstream of the tubular reactor, and at least one second introduction of one or more, identical or different, seeding agents into the tubular reactor.

The present invention provides a treatment method of a radioactive iodine-containing fluid, comprising passing the radioactive iodine-containing fluid through an adsorbent for iodine consisting of a silver-containing binderless zeolite molded body having a silver content of 50 mass % or less, to adsorb the radioactive iodine on the adsorbent for iodine.

The present invention provides a treatment method of a radioactive iodine-containing fluid, comprising passing the radioactive iodine-containing fluid through an adsorbent for iodine consisting of a silver-containing binderless zeolite molded body having a silver content of 50 mass % or less, to adsorb the radioactive iodine on the adsorbent for iodine.

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.

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.

The present invention relates to a process for preparing a pulverulent, porous crystalline metal silicate, comprising the following steps: a) hydrothermal synthesis in an aqueous mixture comprising (A) at least one silicon source, (B) at least one metal source and (C) at least one mineralizer to obtain an aqueous suspension comprising a porous crystalline metal silicate as reaction product; and b) calcination of the reaction product, characterized in that the calcination is conducted by means of flame spray pyrolysis at an adiabatic combustion temperature within a range of 450-2200° C., wherein the suspension having a solids content of 70% by weight which is obtained in step a) is sprayed into a flame generated by combustion of a fuel in the presence of oxygen to form a pulverulent, porous crystalline metal silicate.

Catalysts and methods for use in conversion of glycerides and free fatty acids to biodiesel are described. A batch or continuous process may be used with the catalysts for transesterification of triglycerides with an alkyl alcohol to produce corresponding mono carboxylic acid esters and glycerol in high yields and purity. Similarly, alkyl and aryl carboxylic acids and free fatty acids are also converted to corresponding alkyl esters. Catalysts are capable of simultaneous esterification and transesterification under same process conditions. The described catalysts are thermostable, long lasting, and highly active.

The present invention relates to a process for preparing zeolite crystals having a multimodal particle size distribution, and the sizes of which are between 0.02 μm and 20 μm, said process comprising a first introduction of one or more seeding agents into the tubular reactor or upstream of the tubular reactor, and at least one second introduction of one or more, identical or different, seeding agents into the tubular reactor.

The present invention relates to a process for preparing zeolite crystals having a multimodal particle size distribution, and the sizes of which are between 0.02 μm and 20 μm, said process comprising a first introduction of one or more seeding agents into the tubular reactor or upstream of the tubular reactor, and at least one second introduction of one or more, identical or different, seeding agents into the tubular reactor.

A catalyst includes LTA zeolite including copper ions, wherein a Si/Al ratio of the LTA zeolite is 2 to 50. The catalyst is coated on a honeycomb carrier or a filter. The catalyst removes NOx from a reaction gas at 100° C. or above. The catalyst has an NOx conversion rate of 80% at 450° C. or above.