preparation of olefin via methanol on sapo-34 using organic functionalized sapo-18 as a seed

Sapo-34 with hierarchical porosity has been synthesised by a new synthesis strategy, based on disturbing the growth of the sapo-34 crystals by functionalization of the milled sapo-18 seeds with triethyleamine (tea) and ethylene glycol in order to prohibit their further association and agglomeration.. the crystalline structures of the modified sapo-34 materials with different concentrations of organo functionalized seeds were certified by x-ray diffraction. the morphology and textural properties of the materials was confirmed by fe-sem, and brunauer-emmett-teller surface areas. the acidity of the catalyst was studied by nh3 temperature programmed desorption. according to the n2 adsorption-desorption and the fe-sem of the catalysts produced by maximum amount of modified seed(8%) exhibited smaller and more uniform crystal size(between 200-450nm), a larger surface area ( about 650m2/g) than those produced by lower percent of seed or without modified seed. nh3-tpd analysis indicated partially the increased weak and strong acidity in the catalyst by maximum amount of seed. a high activity and selectivity to light olefins (c2= + c3= +c4=) were obtained from the catalyst synthesized by this new strategy. at the industrial reaction condition in fix bed reactor( temperature and mass ratio water to methanol equal 425c and 1:2.5), the methanol conversion approached 100% and the ethylene–propylene selectivity, light olefins selectivity and the lifetime of the catalyst reached maximums of 82%, 90% and 500 min, respectively.