摘要:
An in-extrudate reaction mixture to be effectively crystallized is effectively crystallized to produce zeolitic or non-zeolitic molecular sieves. The reaction mixture is heated within a slowly rotating, double-walled reactor vessel wherein a heated medium is conducted within a space formed between the double walls of the vessel. Thus, the reaction mixture is contacted by a uniformly heated wall while being gently tumbled at low speed. The tumbling action serves to uniformly distribute the heat within the reaction mixture without subjecting the mixture to such shearing that could damage shaped particles. A relatively high quantity of reaction mixture can be handled in that way to maximize the production volumes and reduce production costs.
摘要:
Process for the preparation of a crystalline solid comprising at least one zeolitic material, in which the solid is crystallized from at least one precursor compound and the reaction discharge of the crystallization is fed directly to a drying stage.
摘要:
The invention is directed to a method of synthesizing aluminophosphate and silicoaluminophosphate molecular sieves and in particular to the synthesis of aluminophosphate and silicoaluminophosphate molecular sieves using the synthesis templates that contain two dimethylamino moieties in combination with hydrogen fluoride. The use of this template in combination with hydrogen fluoride results in good quality SAPO molecular sieves of CHA framework type with low levels of silicon that are produced in relatively short crystallization times.
摘要:
Applicants have developed a continuous process for synthesizing various molecular sieves. The process enables one to control both the particle size and particle size distribution. Any of the molecular sieves represented by the empirical formula on an anhydrous basis: rR2O:(SixAlyPz)O2, where R is at least one structure directing agent, “r”, “x”, “y” and “z” are the mole fractions of R, Si, Al and P respectively, can be prepared using this process. The process involves continuously adding separate streams comprising reactive sources of at least each framework element into a continuous crystallization reactor. Either interstage backmixing is introduced or the number of stages is adjusted in order to control particle size.
摘要:
This invention relates to the synthesis of large pore composite molecular sieves and to the synthetic large pore composite molecular sieves so produced. The molecular sieves of the invention have the same general utilities of the comparable molecular sieves of the prior art but have been found to be superior catalysts and absorbents. This invention relates to a hydrothermal synthesis of large pore molecular sieves from nutrients, at least one of which contains an amorphous framework-structure, and which framework-structure is essentially retained in the synthetic molecular sieve. This invention stems from a discovery that the intrinsic porosity characteristics of a nutrient that possesses an amorphous cation oxide-framework can be substantially retained in the final molecular sieve containing product formed by a hydrothermal process by carefully controlling the conditions under which the hydrothermal process is conducted. For example, the invention contemplates retention of the particle size in a final molecular sieve-containing product that corresponds with that of an amorphous cation oxide-framework nutrient used in its manufacture. This invention drives the selection of process conditions to achieve one or more of macro and meso porosity (“large pore composite porosity”) in the final molecular sieve product as a direct product of the hydrothermal reaction producing the molecular sieve. The invention allows the production of a molecular sieve that is in situ incorporated in the framework morphology of a solid cation oxide-framework used in the molecular sieve's manufacture.