Apparatus for preparing hydrazo-dicarbonamide using urea as starting material
First Claim
1. An apparatus for preparing hydrazodicarbonamide comprising:
- a pyrolysis furnace to obtain biuret and ammonia by pyrolyzing urea;
a recrystallization reactor to purify the biuret obtained from the pyrolysis furnace;
a first reactor to obtain an metal monohalobiuret salt by reacting the biuret with metal hypohalogen compound or with halogen and base;
a second reactor to synthesize the hydrazodicarbonamide by reacting the monohalobiuret metal salt with ammonia; and
an ammonia evaporator to separate the excess ammonia from hydrazodicarbonamide and to supply the separated ammonia to an ammonia concentrator, wherein wherein the ammonia concentrator is to concentrate the excess ammonia and ammonia obtained at the pyrolysis furnace, and is to supply the concentrated ammonia to the second reactor.
1 Assignment
0 Petitions
Accused Products
Abstract
The present invention relates to a method and apparatus for preparing hydrazodicarbonamide using urea as starting material economically and environmentally desirably. The apparatus includes a pyrolysis furnace to obtain biuret and ammonia by pyrolyzing urea; a recrystallization reactor to purify the biuret obtained from the pyrolysis furnace; a first reactor to obtain an metal monohalobiuret salt by reacting the biuret with metal hypohalogen compound or with halogen and base; a second reactor to synthesize the hydrazodicarbonamide by reacting the monohalobiuret metal salt with ammonia; and an ammonia evaporator to separate the excess ammonia from hydrazodicarbonamide and to supply the separated ammonia to an ammonia concentrator.
11 Citations
3 Claims
-
1. An apparatus for preparing hydrazodicarbonamide comprising:
-
a pyrolysis furnace to obtain biuret and ammonia by pyrolyzing urea; a recrystallization reactor to purify the biuret obtained from the pyrolysis furnace; a first reactor to obtain an metal monohalobiuret salt by reacting the biuret with metal hypohalogen compound or with halogen and base; a second reactor to synthesize the hydrazodicarbonamide by reacting the monohalobiuret metal salt with ammonia; and an ammonia evaporator to separate the excess ammonia from hydrazodicarbonamide and to supply the separated ammonia to an ammonia concentrator, wherein wherein the ammonia concentrator is to concentrate the excess ammonia and ammonia obtained at the pyrolysis furnace, and is to supply the concentrated ammonia to the second reactor. - View Dependent Claims (2, 3)
-
Specification
-
- Resources
-
Current AssigneeDongjin Semichem Co., Ltd.
-
Original AssigneeJ-Chemical Corporation
-
InventorsHan, Sang-Jin, Lee, Chun-hyuk
-
Primary Examiner(s)Griffin; Walter D.
-
Assistant Examiner(s)YOUNG, NATASHA E
-
Application NumberUS11/747,596Publication NumberTime in Patent Office487 DaysField of Search422/187, 422/189, 564/34US Class Current422/609CPC Class CodesC07C 281/06 Compounds containing any of...
