An Investigation into the Effectiveness of Dielectric Barrier Discharge Plasma for the Transformation of Linear Siloxanes from Gas to Solid Phase

M.M. Tahiyat, T.I. Farouk, S. Hoque
EPA P3: University of South Carolina,
United States

Keywords: DBD (dielectric barrier discharge), siloxane, plasma, Renewable, efficiency, cost-effective

Summary:

Currently, siloxane from landfill gases is removed through adsorption on activated carbon filters, which have limited regeneration ability. Silica gel and alumina adsorbents potentially possess longer lifecycles but require high temperature for desorption. Polyacrylic acid-based polymer adsorbents have improved regenerative ability but are hindered by low adsorption capacity. Water has limited effectiveness due to its low solubility of silicon compounds and the constant need for recycling at elevated temperature, incurring a high overhead cost. Thus, all existent techniques suffer from poor efficacy or contribute to the waste cycle in the long run. It has been demonstrated that the proposed DBD systems is capable of dissociating volatile organosilicate contaminant (VOSC) in gas phase from a carrier stream and recombine the dissociated molecules to a polymerized form: polydimethylsiloxane (PDMS) in solid phase, thus, removing the contaminant from the carrier stream. The removal of VOSC is accomplished without the usage of any adsorbent or adsorbate and at atmospheric pressure and temperature. One of the exciting features of the proposed technology is that DBD reactor cells are considered very robust and do not require periodic replacement and regeneration like conventional filters and adsorbents. This will be financially beneficial as it will greatly eliminate capital expenditure in replacement and regular maintenance of conventional equipment required for removal of volatile organosilicate compounds. Moreover, the byproduct from the proposed method is polydimethylsiloxane, which has commercial importance in industrial, medical and industrial applications. This could serve as a potential opportunity for revenue for funding agencies.