APPLICATIONS OF TECHNOLOGY:
- Active air filtration for residential and commercial buildings and industry
- Passive air filtration (e.g., paint, coatings, wall board)
- HVAC systems
ADVANTAGES: Compared to existing, state-of-the-art materials:
- Enables lower energy expenditure for ventilation
- More efficient removal of formaldehyde from air (80% removed) with formaldehyde completely decomposed
- Longer operational life
- Compatible with existing HVAC systems
- Demonstrated scalability
Scientists at Berkeley Lab have developed a catalyst and deployment devices to improve indoor air quality and reduce ventilation energy needs. The catalyst, a manganese oxide (MnOx), can be synthesized inexpensively from commercially available chemicals. It catalyzes the oxidation of several volatile organic compounds (VOCs), most notably formaldehyde and acetaldehyde, to carbon dioxide and water. The MnOx can be applied with off-the-shelf hardware to a particle filter, which may then be placed in a heating, ventilation, and air conditioning (HVAC) system to reduce VOCs in indoor air.
The scientists have also developed systems for using activated carbon fiber (ACF) filters to remove additional VOCs from gas streams. The catalyst and ACF can be used separately or together. Used together, the first filter removes particles, the catalyst efficiently removes aldehydes and a specific range of VOCs, and the ACF filter adsorbs remaining VOCs and removes ozone. The ACF can be periodically regenerated in-situ with heated air (at 150°C) to drive off adsorbed VOCs and vent them to the outdoors. Such a system can effectively clean air while consuming 15-20% of the typical energy needed for ventilation with outdoor air.
In an ongoing field test, a particle filter treated with the catalyst has been placed in an existing office building HVAC system. Under conditions with a normal air stream velocity, these filters have reduced the formaldehyde and acetaldehyde content of indoor air by 80% and reduced the content of other VOCs in indoor air by smaller amounts.
In a laboratory building, the catalyst has been used continuously for more than 65 days with only a small drop in formaldehyde removal performance. Further tests show that high humidity conditions do not adversely affect the performance of the catalyst or the ACF system. In addition, the catalyst may be applicable in passive air cleaning, by incorporating it into wallboard or coatings on indoor surfaces, including within ducts and on heating or cooling coils.
In most buildings, VOCs are removed by flushing out indoor air with outdoor air. However, this process increases energy use significantly because the supplied outdoor air must be heated or cooled, and dehumidified, depending on weather conditions. Alternative air cleaning systems contain granular activated carbon or chemisorbents (e.g., sodium permanganate), but they are infrequently used because of their expense, weight, volume, airflow resistance, and need for regular replacement. The Berkeley Lab technologies overcome these limitations, providing a cost- and energy-efficient means for cleaning air of VOCs and ozone.
- Field-tested prototype of particle filter with catalyst.
- Bench prototype for production of catalyst and its application to particle filters.
- Bench scale tests of ACF system and of use of the catalyst in conjunction with the ACF system.
STATUS: Patent pending. Available for licensing or collaborative research.
FOR MORE INFORMATION:
Sidheswaran, M.A., Destaillats, H., Sullivan, D.P., Larsen, J., Fisk, W.J. "Quantitative room-temperature mineralization of airborne formaldehyde using manganese oxide catalysts," Applied Catalysis B: Environmental 107 (2011) 34-41.
SEE THESE OTHER BERKELEY LAB TECHNOLOGIES IN THIS FIELD:
REFERENCE NUMBER: IB-2970