SBIR-STTR Award

Separation of trace quantities of species from gas and liquid streams is a major problem for both defense and commercial applications. The motivation for removal varies greatly in different applications. Examples include; safety (gas masks and protective clothing in chemical warfare and hazardous industrial environments), higher semiconductor yields (particularly for deep UV lithography), drinking water clean-up (such as lead), and production of UHP chemicals for electronics. Separations for these and other applications are growing rapidly as a result of increasing environmental, safety and energy regulation as well as the increased risk of chemical warfare by terrorist organizations. For the separation of species from dilute streams, the most preferred method is adsorption. Activated carbons are the preferred adsorbent because of their very high surface area and low costs. However, it is difficult to change surface chemistry of carbons to achieve enhanced selectivity, greater adsorbent capacity, greater retention and possible catalytic decomposition toxic compounds. This project explores the use of novel surface modification schemes using chemical weapons simulants and ammonia/amines as sample toxic gases/vapor. The improvement in absorber performance as a function of surface modification, base activated carbon, and water content will be demonstrated.

Separation of trace quantities from streams is a major problem for both defense and commercial applications. Examples include; safety (gas masks), higher semiconductor yields (deep-UV lithography), drinking water clean-up (lead), and production of UHP chemicals for electronics. Separations for these and other applications are growing rapidly as a result of increasing environmental, safety and energy regulation as well as the risk of chemical warfare. For the separation of species from dilute streams, the preferred method is adsorption with activated carbon because of their very high surface area and low cost. However, it is difficult to change surface chemistry to achieve enhanced selectivity and greater capacity. In Phase I, we demonstrated surface modification of activated carbons which led to a 20 times improvement in specific adsorption of CK gas at low pressure. However, the extent of treatment and surface area loss was found to be a function of carbon pore size. In Phase II, we will modify a series of different carbon forms (activated carbon granules, activated carbon fibers, activated carbon powder in polymer fibers, carbon monoliths) with both acid and base groups. This will demonstrate not just adsorption uptake but rather all required aspects of adsorber performance (pressure drop, kinetics, etc.). Demonstration adsorbers will be produced and tested for both gas masks and for the removal of ammonia for the IC industry. These prototypes will be tested against conventional adsorbents.