Q1: Fertiliser plants get their N₂ requirements

ANS:A - by fractionation of liquified air.

Fertilizer plants typically obtain their nitrogen (N2) requirements from fractionation of liquefied air. Nitrogen is an essential element for plant growth and is a major component of fertilizers. In industrial fertilizer production, nitrogen is commonly sourced from the air through a process known as cryogenic air separation. This process involves cooling and compressing atmospheric air to liquefy it, then separating the various components of air through fractional distillation. Nitrogen, which accounts for about 78% of air volume, can be isolated as a pure gas through this process. While other methods such as dissociation of oxides of nitrogen or using coal gas (coke oven gas) and producer gas can potentially provide nitrogen, they are less commonly used compared to fractionation of liquefied air, especially in large-scale fertilizer production. Fractionation of liquefied air offers a reliable and efficient method for obtaining nitrogen on a commercial scale, making it the preferred choice for fertilizer plants.