Why is a pure nitrogen tower installed in the air separation main tower?
Thread Content
The purity of liquid nitrogen at the top of the air separation tower already meets the requirements; then why is it still necessary to install a pure nitrogen tower at the top of the air separation tower?
First, to produce oxygen, two-stage distillation is required. Second, in order to achieve a higher oxygen extraction rate, it is necessary to reduce the oxygen content in nitrogen; that is, high-purity nitrogen must be produced in the upper column~~
To increase the amount of nitrogen gas produced more effectively, washing the rising steam with the reflux liquid can yield a greater quantity of nitrogen gas
It is related to the plant’s processing technologies; generally, less nitrogen is required in methanol production, so there is no need for a pure nitrogen tower, whereas urea fertilizer production demands high purity of nitrogen, thus a pure nitrogen tower is necessary.