What is the primary function of a molecular sieve in oxygen concentrators?

The primary function of a molecular sieve in oxygen concentrators is to absorb nitrogen and trace gases from the air. The molecular sieve, typically made of zeolite material, operates on the principle of selective adsorption, where it preferentially adsorbs nitrogen molecules while allowing oxygen molecules to pass through.

This process is vital because the atmospheric air is composed of approximately 78% nitrogen and 21% oxygen, along with trace amounts of other gases. By removing the nitrogen, the concentrator enriches the remaining gases in oxygen, which can then be delivered to the patient at a higher concentration. This efficient separation is crucial for therapeutic applications, where high-purity oxygen is necessary for effective treatment.

The focus on nitrogen absorption is what differentiates the molecular sieve's function from the other choices. Instead of absorbing oxygen or increasing pressure, the sieve specifically targets nitrogen to optimize the output of oxygen-rich air. Additionally, while the filtering of impurities might occur through different system components, the molecular sieve's role is strictly in the absorption of specific gases, making its primary function distinct.