| 摘要 |
The invention relates to a process for increasing the capacity of an existing urea process comprising, in the high-pressure section of the process, a reactor in which carbon dioxide and ammonia react to form urea, a thermal stripper in which the process stream from the reactor is stripped by supplying heat or an ammonia stripper in which the process stream from the reactor is stripped by supplying heat with the aid of ammonia as stripping gas and a condenser in which the stripping gases are condensed, whereupon the condensate formed is returned to the reactor, in which process the N/C ratio in the reactor is between 2.8 and 3.3 mol/mol, the pressure in the high-pressure section of the process is between 13.5 and 16.0 Mpa, at least a portion of the process stream from the reactor is stripped in a CO-stripper in which the process stream from the reactor is stripped by supplying heat and with the aid of carbon dioxide as stripping gas and the condensing capacity in the high-pressure section of the process is increased. |
