The potential use of sorbents to manage emissions of ultrafine metal nuclei from residual oil combustion was investigated by using an 82-kW-rated laboratory-scale refractory-lined combustor. Without sorbent addition, baseline measurements of the fly ash particle size distribution (PSD) and chemical composition indicate that most of the metals contained in the residual oil form ultrafine particles (∼0.1 μm diameter). These results are consistent with particle formation via mechanisms of ash vaporization and subsequent particle nucleation and growth. Equilibrium calculations predict metal vaporization at flame temperatures and were used to define regions above the dew point for the major metal constituents (iron [Fe], nickel [Ni], vanadium [V], and zinc [Zn]) where vapor-phase metal and solidphase sorbents could interact. The addition of dispersed kaolinite powder resulted in an approximate 35% reduction in the ultrafine nuclei as determined by changes to the PSDs as well as the size-dependent chemical composition.
Bibliographical noteFunding Information:
Portions of this work were conducted under EPA Purchase Order No. 1 CR183NASA with J.O.L. Wendt and EPA Contract 68-C-99-201 with ARCADIS Geraghty & Miller, Inc. This work was also partially supported by the KEMCO academic research fund, No. 2002CCT03P01, in Korea. The authors would like to thank EPAs Shirley Wasson for her kind assistance with the XRF analysis. The research described in this article has been reviewed by the Air Pollution Prevention and Control Division, U.S. EPA, and approved for publication. The contents of this article should not be construed to represent Agency policy nor does mention of trade names or commercial products constitute endorsement or recommendation for use.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)