公开(公告)号：DE502004011507D1

公开(公告)日：2010-09-23

申请号：DE502004011507

申请日：2004-01-16

Applicant: BASF SE

Inventor： KUHRS CHRISTIAN ,  DANZ ECKEHARD ,  STEINER WOLFGANG ,  RAHN RALF-THOMAS ,  GRASSLER THOMAS ,  GEIER REINER ,  HARTH KLAUS ,  HOELZLE MARKUS

IPC: C07D251/60

公开(公告)号：AT477247T

公开(公告)日：2010-08-15

申请号：AT04702691

申请日：2004-01-16

Applicant: BASF SE

Inventor： KUHRS CHRISTIAN ,  DANZ ECKEHARD ,  STEINER WOLFGANG ,  RAHN RALF-THOMAS ,  GRASSLER THOMAS ,  GEIER REINER ,  HARTH KLAUS ,  HOELZLE MARKUS

IPC: C07D251/60

Abstract: The present invention relates to a process for the catalytic preparation of melamine by decomposition of urea over particular solid catalysts using a main reactor and an after-reactor. A catalyst having a low Lewis acidity is used in the main reactor and a catalyst having an equal or preferably higher Lewis acidity is used in the after-reactor.