Title:
尿素製造方法
Document Type and Number:
Japanese Patent JP4358428
Kind Code:
B2
Abstract:
A urea synthesis process with improved heat economy, wherein a urea synthesis solution obtained by removing most of the unreacted ammonium carbamate by stripping with carbon dioxide at a pressure approximately equal to a urea synthesis pressure is subjected to a high and low pressure decomposition. The gas mixture obtained from the high-pressure decomposition is condensed in at least two steps. Gases obtained from the stripping of the urea synthesis solution, after an initial condensation may be alternatively routed into the high-pressure decomposition column thus facilitating the decomposition of unreacted ammonium carbamate; may be mixed with off-gases from the high-pressure decomposition column and routed to an indirect heat-exchanger for concentrating the aqueous urea solution and facilitating the condensation of the off-gases from the high pressure decomposition column; or may be routed to a condenser for the gas mixture obtained from the high-pressure decomposition after it has underwent indirect heat-exchange with the aqueous urea solution, thus facilitate the further condensation of these gases.
Inventors:
Kinichi Yoshida
Kenji Yoshimoto
Yasuhiko Kojima
Kenji Yoshimoto
Yasuhiko Kojima
Application Number:
JP2000334395A
Publication Date:
November 04, 2009
Filing Date:
November 01, 2000
Export Citation:
Assignee:
Toyo Engineering Corporation
International Classes:
C07C273/04; C07C275/00
Domestic Patent References:
| JP10182587A | ||||
| JP58067661A | ||||
| JP57050954A | ||||
| JP56110662A |
Attorney, Agent or Firm:
Akio Miyazaki
Nobuyuki Kaneda
Ishibashi Masayuki
Nobuyuki Kaneda
Ishibashi Masayuki