The maximum oxygen concentration obtained using a conventional single-stage pressure swing adsorption unit is ca. 95% balanced mostly with argon. However, there are several applications requiring simple and compact units for producing high-purity oxygen (>= 99%), such as medical, military, or aerospace. This article studies a single-stage vacuum pressure swing adsorption (VPSA) unit, loaded with silver-based zeolite AgLiLSX, for producing ca. 1 L-STP.min(-1) of high-purity oxygen. The unit was designed on the basis of the experimental and simulation results obtained with a lab-scale unit. For a product concentration of 99.0%, the recovery obtained was ca. 8.0% with a productivity of 9.0 m(3).h(-1).ton(-1).