The ASPEN plant is a medium sized air separation plant designed to produce liquid nitrogen, oxygen and, as an option, liquid argon by cryogenic distillation of atmospheric air. In addition, when operating in maximum oxygen mode, gaseous nitrogen is also available, if required, when there is a pipeline or other on-site nitrogen requirement or to liquefy for additional liquid nitrogen capacity. Capacities range from 15 to 35 metric tons per day. The ASPEN plant is designed to minimize shipping and allow for rapid installation by providing the plant in four distinct modules: the main air compressor, the air treatment module, the recycle compressor, and the cold box. The plant system is self-contained and can be completely installed outdoors. The plants require a source of cooling water, power supply and a simple foundation.

The ASPEN plants are designed to meet the most severe operating conditions. Over 35 ASPEN plants have been deployed producing liquid oxygen, nitrogen and argon for medical, industrial, oil field and military applications in some of the most remote regions of the world.