Assertion: nitrogen | /r/HasProperty | separated by distillation
Facets:
value: usually
type: TEMPORAL
value: from air
type: TRANSITIVE-OBJECT
Source sentences:
text: If the gas is exposed to air it will pick up moisture, although I don't know how this would be done because I believe nitrogen is usually separated from air by distillation and water would become ice and be separated from other gases before the nitrogen was isolated.