Start of gas phase operation
Thread Content
After starting up gas fractionation and completing nitrogen purging for airtightness, is it necessary to perform dry gas purging?
The question is rather vague. What does it mean by starting gas fractionation? Is it an air separation unit that uses cryogenic methods? What does it mean to achieve airtightness through nitrogen purging? What does dry gas refer to? (Dry gas, including dry air, dry nitrogen, and other dry gases). Please specify, to facilitate discussion.
C3-:C4 separation, with dry gas being methane.
I work in air separation, but there is one thing that can be applied here. Based on the physicochemical properties of the medium used in production, it is determined whether nitrogen could become an impurity in the product or cause contamination of the production equipment after manufacturing; from this perspective, it is decided whether gas purging with dry gas is necessary. For reference.
It is necessary, as nitrogen is a non-condensable gas that affects the operating pressure of the tower.
It is also necessary to consider whether there is any contamination of the product and whether it affects the product’s purity, etc
Not necessary; release nitrogen to maintain a slight positive pressure for material displacement.
We reduced the pressure of nitrogen to a slight positive level; indeed, nitrogen, being a non-condensable gas, affects the cooling effect. I slightly opened the bypass line of the safety valve and used the pressure increase process to discharge the nitrogen into the low-pressure gas network and then to the flare.