Appeal No. 1997-2353 Page 2
Application No. 08/405,912
BACKGROUND
Appellants' invention relates to a method of producing
urea with the aim of increasing the production capacity while
reducing energy consumption (specification, page 2). An
understanding of the invention can be derived from a reading
of exemplary claim 1, which is reproduced below.
1. A continuous process of producing urea comprising
the steps of:
- reacting ammonia and carbon dioxide in a first reaction
space at high temperature and pressure, the ammonia/carbon
dioxide ratio being less than 3;
- effecting a gas stripping with said carbon dioxide of a
first reaction mixture leaving said first reaction space;
- feeding the stripped first reaction mixture to a first
urea recovery section;
- feeding high purity ammonia and carbon dioxide to a
second reaction space;
- feeding a second reaction mixture including urea,
carbamate and unreacted ammonia leaving said second reaction
space, to a second recovery section;
- separating urea, carbamate and unreacted ammonia in
said second recovery section;
- recycling the carbamate and unreacted ammonia leaving
said second recovery section respectively to said first and
second reaction spaces.
The prior art references of record relied upon by the
examiner in rejecting the appealed claims are:
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