Lithium hydroxide (LiOH) absorbent is used for both active CO2 absorption (powered scrubber systems) and passive CO2 absorption (hanging sheets) and where cold temperatures are common, such as in submarines. These ExtendAir® cartridges have the same cylindrical form as our calcium-based CO2 products, but are typically larger in diameter and length. With storage space being critical on submarines, ExtendAir® cartridges provide 55% increase in absorbent weight per given storage volume over lithium granules. What this means to the submarine crew is increased life support duration without sacrificing the limited space available.

The US Navy and British Royal Navy recently approved ExtendAir® lithium hydroxide CO2 absorbent as their emergency CO2 control solution in the event of a Disabled Submarine (DISSUB). The Royal Navy retrofit is almost complete and the US Navy has started the retrofit process for the Virginia-class submarine. Our national stock number for the US Navy product is NSN 6810-01-560-3015, Micropore part number RM-0601C. In a direct comparison at the US Naval Submarine Medical Research Laboratory (NSMRL) of hanging curtains of ExtendAir® absorbents and granule absorbents, ExtendAir® absorbents rate of CO2 absorption was 2 to 5 times better than the granule curtains. See this link for more information on the Royal Navy’s decision process to outfit ExtendAir® curtains for their fleet.

Micropore’s technology improves both active mode and passive mode CO2 scrubbing performance with minimal modifications to the existing scrubbers. In addition, the ExtendAir® LiOH cartridges have substantially less powdering associated with handling, proven by passing stringent MIL-STD shock and vibration acceptance tests, and can be deployed for passive absorption without significant risk of breathing lithium hydroxide powder.

An alternative packaging choice by many NATO submarine fleets for passive CO2 filtration has been the ExtendAir® LiOH pre-cut curtains. In this form factor, fanfold sheets of our absorbent are fastened to either a scrim material or sandwiched in between a non-woven curtain material. This fan fold is sealed in heavy foil bags and then placed into final outer packaging, either a metal ‘ammo’ style container or soft fire/stain resistant pouch. Our most popular curtain in this configuration is the OM-0612K as it provides the highest density of absorbent yielding lowest installed footprint on the submarine. Click on this link to review our ‘family’ of LiOH absorbent solutions.

For daily use, active filtration, we have introduced the ExtendAir® PowerCube™. This product replaces the plastic container granule-filled products found on many diesel/electric submarines around the world. The PowerCube™ system comprises of a specially made canister designed to fit in the current scrubber frame systems and a cube of our standard ExtendAir® CO2 absorbent. This system is 33% more efficient than the granule scrubbers and has improved absorption rate permitting larger crew size. Follow this link for more details.

We are ready to evaluate your specific needs from prototyping to system retrofit. If you have an application, contact Micropore with your requirements.



In a DISSUB situation, maintaining the quality of your atmosphere with the ExtendAir® curtains is vital to survival. Knowing when to deploy the curtains is just as critical. The Analox Sub MkIIP portable hyperbaric monitor continuously monitors oxygen, carbon dioxide, pressure and temperature in the escape compartment and is the only continuous analyzer compliant with NATO STANAG 1320.

Link: http://www.analox.net/proddetail.php?productid=69&ref=79