1933 Hetherington 1937116 Urea Process
This invention describes a process to recycle carbamate in liquid form, thus possible by means of pumps. This can be realized by adding a substance in which ammonium carbamate dissolves or lowers the melting point of it. These substances can be urea, ammonium formate or formamide, or water. To limit the decomposition of urea, the temperature should be limited to 150 degC and the residence time should be small.
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