Primarily used in food packaging, food preservation, pharmaceutical packaging, pharmaceutical gas replacement, and pharmaceutical gas transportation. The produced nitrogen usually undergoes treatments such as sterilization, dust removal, and dehydration to meet the specific requirements of these industries. The food industry does not have high demands for nitrogen purity; many applications can be met with a purity of 98% or higher. In contrast, the pharmaceutical industry typically requires nitrogen with a purity of 99.9%. For small-scale nitrogen usage in the food industry, membrane separation is commonly employed, while pressure swing adsorption is preferred for larger-scale applications.

Filling fruits, vegetables, tea, and other products with nitrogen for storage and preservation is also one of the most advanced methods. This technique slows down the metabolic processes of fruits, vegetables, and tea leaves by placing them in a high-nitrogen, low-oxygen environment, inducing a state similar to hibernation and inhibiting ripening, thereby enabling long-term preservation. According to experiments, apples stored with nitrogen remain crisp and refreshing even after eight months. Food preservation applications include nitrogen storage and preservation of grains, fruits, and vegetables; nitrogen packaging for meat, cheese, pickled vegetables, tea, and coffee; nitrogen displacement of oxygen to preserve juices, edible oils, and jams; and purification and coverage of various bottled alcoholic beverages.

Using nitrogen to keep grains in a dormant and oxygen-deprived state slows down their metabolism, effectively preventing insect infestation, mold growth, and spoilage while ensuring the grains remain uncontaminated. Storing grains such as rice, wheat, barley, corn, and paddy by replacing air with nitrogen can prevent insect damage, overheating, and mold formation, ensuring quality preservation through the summer. This method involves tightly sealing the grains with plastic sheeting, first creating a low vacuum, and then filling it with nitrogen of about 98% purity until internal and external pressures are balanced. This reduces oxygen levels in the grain pile, slows down the grains' respiratory activity, inhibits microbial reproduction, and kills all pests within 36 hours due to oxygen deprivation. This oxygen reduction method for pest control not only saves significant costs but also maintains the freshness and nutritional value of the grains while preventing bacterial contamination and chemical pollution.