Grantee Research Project Results
Final Report: Catalytic Control of Low Concentration Complex Emissions
EPA Contract Number: 68D00253Title: Catalytic Control of Low Concentration Complex Emissions
Investigators: Yadav, Tapesh , Miremadi, Bijan
Small Business: Nanomaterials Research Corporation
EPA Contact:
Phase: I
Project Period: September 1, 2000 through March 1, 2001
Project Amount: $70,000
RFA: Small Business Innovation Research (SBIR) - Phase I (2000) RFA Text | Recipients Lists
Research Category: Air Quality and Air Toxics , SBIR - Air Pollution , Small Business Innovation Research (SBIR)
Description:
Low concentration complex emissions, i.e. a mixture of volatile organic compounds (VOCs) and toxic air pollutants (TAPs), are of significant concern. They are emitted by fuel storage facilities, paint booths, small shops, defense/paramilitary facilities, and other entities. Often these sources are located close to densely populated or neighborhoods. Control of low concentration complex emissions is needed to reduce the adverse impact of low concentration complex emissions. This would reduce smog and pollution and improve environmental health. This EPA Phase I focussed on the treatment of complex low concentration emissions of methylethylketone (MEK), toluene, and iso-octane or from a mixture of these compounds, utilizing field assisted catalysis. This report presents results suggesting electrically activated catalysis to be a promising technology for the treatment of VOCs at low concentrations.Many technologies have been and are being developed to treat VOCs. Some of the more important processes are,
Adsorption: uses activated carbon to adsorb VOCs. The process often requires expensive pretreatment. The process is driven by thermodynamic factors and in most cases does not result in a processed stream that has low levels of VOCs. The process has limited life and requires regular replacement of the adsorbent. Finally, the process does remove VOCs from air, but creates another waste that is the spent adsorbent with VOCs.
Incineration: uses heat and high temperatures to decompose VOCs. This technology is practical mostly at high concentrations; even there, the energy penalty is excessive, selectivity poor, and the byproducts formed are of significant concern as pollutants.
Scrubbing: utilizes solvents that actively absorb and chemically react with the VOCs. Once again, the solvent-related costs are high, secondary pollutants are formed, and above all the fate of VOCs is still far from benign.
In summary, none of the alternative processes meet all the needs for a commercially viable process for low concentration complex emissions control. A breeakthrough is needed.
Recently, Nanomaterials Research Corporation team made a
serendipitous and significant discovery relating to the field of catalysis.
These results have been reproduced at MIT and University of Colorado, Boulder
and were, in September, 2000 published by Chemical Communications (Low-temperature hydrogen production using electrically activated
catalysts
Bijan Miremadi, Tapesh Yadav, Jun Zhang and John Falconer. Chem.
Comm., 19, September (2000) 1875). We discovered that certain nanoscale
forms of base metal catalysts show unusual catalytic behavior in the presence of
electric field. In particular it was observed that when electric current passes
through catalysts such as metal oxide and perovskites, the materials show useful
chemical reactions at low temperatures and ambient pressures. Figure 1
schematically shows the process.
Figure 1. Field Assisted Catalysis. The active element is the gas phase heterogeneous catalyst with electrode. The feed and product streams are fluids.
In early work, we experimented with 10 to 10,000 ppm of VOC as feed in air. The specific VOC which we experimented with include Toluene, Methane, Propanol, Ethanol, and Methanol. Remarkably, we observed 25% to 80% conversion of feed stream in a stirred type reactor at low temperatures and near ambient pressures. It is known to those in the art, that reactor engineering and further optimization could yield more desirable results. The concentration of the VOC treated is in the range of interest for complex emissions. Given that electrical energy is readily available, field assisted catalysis may offer a unique opportunity for complex emissions treatment.
The innovation here is to use field assisted catalysis so as to develop low-cost complex emissions treatment for air quality improvements. The specific focus of this effort is to treat octane, MEK, and toluene in air.
Summary/Accomplishments (Outputs/Outcomes):
This effort used base metal oxide nanopowder catalysts in combination with electrical current to treat common VOCs such as MEK, toluene, and gasoline (iso-octane). We found that electrically activated catalysis offers a convenient method for treatment commonly found VOCs in low concentrations. The key advantage of this technology are the low cost, simplicity, desirable byproducts (carbon dioxide and water), and the ability to rapidly start up and shut down.Conclusions:
Electrically activated catalysis offers a convenient method for treatment commonly found VOCs in low concentrations.Supplemental Keywords:
Electrically Activated, Catalysis, VOC Treatment, Low Concentration Emissions., RFA, Scientific Discipline, Air, Toxics, Sustainable Industry/Business, air toxics, cleaner production/pollution prevention, Sustainable Environment, Chemistry, VOCs, Technology for Sustainable Environment, New/Innovative technologies, tropospheric ozone, Engineering, Engineering, Chemistry, & Physics, air pollutants, control, volatile air toxics, air pollution control, pollution control technologies, toxic emissions, smog, catalysts, air pollution, pollution control, treatment, pollutants, Volatile Organic Compounds (VOCs), cost effective, VOC treatment, air emissions, pollution preventionThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.