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US 7,001,490 B2Granted
Purification of ammonia by distillation
AssigneeBASF SE
InventorsKarl-Heinz Wostbrock, Gerd Kaibel, Christian Tragut, Gabriele Anken
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AssigneeBASF SE
InventorsKarl-Heinz Wostbrock, Gerd Kaibel, Christian Tragut, Gabriele Anken
Estimating the term…
Crude ammonia is separated into a low boiler fraction, a high boiler fraction and an intermediate-boiling pure fraction by continuous fractional distillation in a distillation apparatus configured either as a dividing wall column or as a system of thermally coupled distillation columns. In the process of the present invention, the low boiler fraction is taken off at the top of the distillation apparatus. The intermediate-boiling pure fraction is obtained at a side offtake which is preferably provided with droplet precipitators. In addition, the gas loading of the distillation column is restricted so that the operating pressure is in the range from 2 to 30 bar and the F factor does not exceed 2.0 Pa0.5.
A process for the continuously operated fractional distillation of crude ammonia to give a low boiler fraction, a high boiler fraction and an intermediate-boiling pure fraction in a distillation apparatus configured either as a dividing wall column or as a system of thermally coupled distillation columns, wherein the low boiler fraction is taken off at the top of the distillation apparatus, the intermediate-boiling pure fraction is obtained at a side offtake and the gas loading of the distillation column is restricted so that the operating pressure is in the range from 2 to 30 bar and the measure of the loading due to the gas stream in the column, as defined by unit length per unit time multiplied by the root of the total density of the gas, does not exceed 2.0 Pa0.5.
A distillation apparatus configured either as a dividing wall column or as a system of thermally coupled distillation columns for carrying out a process for the continuously operated fractional distillation of crude ammonia to give a low boiler fraction, a high boiler fraction and an intermediate-boiling pure fraction wherein the low boiler fraction is taken off at the top of the distillation apparatus, the intermediate-boiling pure fraction is obtained at a side offtake which is provided with droplet precipitators and the gas loading of the distillation column is restricted so that the operating pressure is in the range from 2 to 30 bar and the measure of the loading due to the gas stream in the column as defined by unit length per unit time multiplied by the root of the total density of the gas, does not exceed 2.0 Pa0.5.
Dependencies are inferred from the claim text.