2012 R&D 100 Winner
One of the biggest challenges for engineers of naval submarines is guaranteeing a supply of oxygen for the sailors. Existing carbon dioxide scrubbing techniques use a liquid monoethanol amine (MEA) solution. A 50-year-old technology, MEA systems are bulky, heavy, corrosive, malodorous, and short lived.

The emergence of functional self-assembled nanoporous materials has opened the door to a cleaner, more efficient, and more reliable method for scrubbing carbon dioxide. The Advanced Carbon Dioxide Removal Unit (ACRU), an invention of researchers at Pacific Northwest National Laboratory, Richland, Wash., and Steward Advanced Materials, Chattanooga, Tenn., employs an amine-functionalized granular version of self-assembled monolayers on mesoporous supports (SAMMS) technology, which is noted for its ability to form strong chemical bonds with targeted materials.

Based on technology to remove heavy metals from waste streams, the highly porous silica substrate maximizes the density of chemically active sites, allowing facile diffusion through the domains of the sorbent material. The SAMMS sorbent can capture carbon dioxde directly from the atmosphere and then release it controllably and on demand when a modest amount of heat and/or vacuum is applied.

These characteristics give the ACRU extended lifespan, functionality free of hazardous byproducts or volatile organic compounds, and rapid sorption kinetics not compromised by the diffusion limitations that hinder competing technologies.

Technology
Carbon dioxide scrubbing material

Developers
Pacific Northwest National Laboratory
Steward Advanced Materials

Development Team

Capt. Mario J. Bagaglio, Jr.	Tim Bays	Kenneth Buxton

Dustin Caldwell	April Carman	Glen Fryxell

Dennis Mullen	Kenneth G. Rappe	Jake Tucker

Jesse Willett	Thomas Zemanian

The Advanced Carbon Dioxide Removal Unit Development Team
Thomas S. Zemanian, Principal Developer, Pacific Northwest National Laboratory
Mario J. Bagaglio, Pacific Northwest National Laboratory (retired)
Tim Bays Pacific, Northwest National Laboratory
Kenneth Buxton, Pacific Northwest National Laboratory
Dustin Caldwell, Pacific Northwest National Laboratory
April J. Carmen, Pacific Northwest National Laboratory
Keith Eischeid, Steward Advanced Materials
Glenn E. Frywell, Pacific Northwest National Laboratory (former)
Dennis Mullen, Pacific Northwest National Laboratory
Kenneth Rappe, Pacific Northwest National Laboratory
Jake Tucker, Pacific Northwest National Laboratory
Jesse Willett, Pacific Northwest National Laboratory