CONTROLLING THE PARTICLE SIZE AND PARTICLE SIZE DISTRIBUTIONIN A PROCESS FOR CONTINUOUS SYNTHESIS OF MOLECULAR SIEVES

摘要

Molecular sieves represented by the empirical formula on an anhydrous basis: rR2O : (Si x Al y P z)O2, (where R is at least one templating agent, "r" "x" "y" and "z" are the mole fractions of R, Si, Al and P respectively) are continuously synthesized while simultaneously controlling both the particle size and/or particle size distribution by continuously adding reactive sources of the desired components along with a structure directing agent into a continuous crystallization reactor and using either interstage backmixing or an adjustment to the number of stages in order to control particle size. One especially preferred way to control particle size distribution is to split the product stream into at least two streams and flowing each stream to a wet miller operated at different severity and then reblending to obtain at least a bimodal distribution.