| 摘要 |
PURPOSE:To efficiently obtain ZSM-type zeolite having improved catalyst life and performance, by treating an organic compound-containing ZSM-type zeolite prepared by hydrothermal reaction with an aqueous solution of an alkali hydroxide in a specific concentration or above. CONSTITUTION:Respective raw material components consisting of a silica source, alumina source, alkali (earth) metal source, etc., are mixed with a crystallizing agent consisting of a quaternary alkylammonium salt, etc. Water or an aqueous medium consisting of water is subsequently added to the resultant mixture to provide an aqueous mixture, which is hydrothermally reacted to afford zeolite having a ZSM-type crystal structure. The resultant ZSM-type zeolite containing NH3 as the crystallizing gent and organic compounds is then suitably dried, then treated with an aqueous solution of an alkali hydroxide in >=0.3 N concentration, washed with water, dried and fired to provide the desired ZSM-type zeolite having improved catalyst life. In this case, the crystallizing agent and other organic compounds are decomposed to disappear. |
