title: Selenium Partitioning and Removal Across a Wet FGD Scrubber at a Coal-Fired Power Plant.
abstract: Selenium has unique fate and transport through a coal-fired power plant because of high vapor pressures of oxide (SeO2) in flue gas. This study was done at full-scale on a 900 MW coal-fired power plant with electrostatic precipitator (ESP) and wet flue gas desulfurization (FGD) scrubber. The first objective was to quantify the partitioning of selenium between gas and condensed phases at the scrubber inlet and outlet. The second objective was to determine the effect of scrubber operation conditions (pH, mass transfer, SO2 removal) on Se removal in both particulate and vapor phases. During part of the testing, hydrated lime (calcium hydroxide) was injected upstream of the scrubber. Gas-phase selenium and particulate-bound selenium were measured as a function of particle size at the inlet and outlet of the scrubber. The total (both phases) removal of Se across the scrubber averaged 61%, and was enhanced when hydrated lime sorbent was injected. There was evidence of gas-to-particle conversion of selenium across the scrubber, based on the dependence of selenium concentration on particle diameter downstream of the scrubber and on thermodynamic calculations.
authors.affiliation: ADA-ES, Inc., 9135 S. Ridgeline Blvd., Suite 200, Highlands Ranch, Colorado 80129, United States.
authors.forename: Constance L
authors.initials: CL
authors.lastname: Senior
authors.affiliation: Southern Research, 2000 Ninth Avenue South, Birmingham, Alabama 35205, United States.
authors.forename: Corey A
authors.initials: CA
authors.lastname: Tyree
authors.affiliation: Southern Company Services, Inc. Research & Environmental Affairs, 600 North 18th Street 14N-8195, Birmingham, Alabama 35203, United States.
authors.forename: Noah D
authors.initials: ND
authors.lastname: Meeks
authors.affiliation: Southern Company Services, Inc. Research & Environmental Affairs, 600 North 18th Street 14N-8195, Birmingham, Alabama 35203, United States.
authors.forename: Chethan
authors.initials: C
authors.lastname: Acharya
authors.affiliation: Southern Research, 2000 Ninth Avenue South, Birmingham, Alabama 35205, United States.
authors.forename: Joseph D
authors.initials: JD
authors.lastname: McCain
authors.affiliation: Southern Research, 2000 Ninth Avenue South, Birmingham, Alabama 35205, United States.
authors.forename: Kenneth M
authors.initials: KM
authors.lastname: Cushing
mesh_terms: D017610:Calcium Compounds / Q000737:chemistry; D003031:Coal; D003247:Conservation of Natural Resources; D005740:Gases / Q000032:analysis; D006813:Humidity; D008628:Mercury; D010087:Oxides / Q000737:chemistry; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis; D011210:Power Plants; D015203:Reproducibility of Results; D012643:Selenium / Q000302:isolation & purification*; D013455:Sulfur / Q000737:chemistry*
chemical_list: D017610:Calcium Compounds; D003031:Coal; D005740:Gases; D010087:Oxides; D052638:Particulate Matter; D013455:Sulfur; C016538:lime; D008628:Mercury; D012643:Selenium