| 摘要 |
<p>Process for increasing the mol. ratio SiO2/Al2O3 in the crystal lattice of zeolites, by the removal of water using air or inert gases and then treatment at high temp. with gases contg. chlorine cpds. The novelty is the use of a reactor provided with at leat one opening and in which zeolites with mol. ratio SiO2/Al2O3 below 5 are heated to min. 400 degrees C. in the presence of air or inert gases, and are then subjected to flowing gases, contg. Cl2 or HCl, at 400-700 degrees C. The initial zeolites pref. have a mol. ratio below 4.75, and the treatment is pref. undertaken at a total pressure above 1 absolute atmos. The pref. zeolites are employed in their alkali(ne earth) form, possibly with partial or complete replacement by hydrogen ions. Zeolites rich in SiO2 have improved high temp. stability and better acid resistance; they are very suitable as catalysts for the alkylation or isomerisation of hydrocarbons, or the adsorption of acid gases.</p> |
