Conversion of Sulfur Dioxide to Sulfur Trioxide in Gas Turbine Exhaust

Abstract

Acid dewpoints were calculated from SO2-to-SO3 conversion in gas turbine exhaust. These data can be used as guidelines in setting feedwater temperatures in combined-cycle systems. Accurate settings can prevent corrosion of heat-exchanger (boiler) tubes, thus extending their life time. This study was done using gas turbine engines and a laboratory generator set. The units burned marine diesel or diesel No. 2 fuel with sulfur contents up to 1.3 percent. The exhaust from these systems contained an excess of 20 percent oxygen, and 3–10 percent water vapor. Exhaust temperatures ranged from 728 to 893 K (455 to 620°C).

Kinetic modeling of the CO/H2O/O2/NO/SO2 system: Implications for high-pressure fall-off in the SO2 + O(+M) = SO3(+M) reaction

“…The observed inhibition due to SO 2 was significantly reduced through the addition of NO, an effect not understood in the context of their reaction mechanism. As we have shown previously for NO X [13] and CH 4 [18,19], kinetic interactions between perturbing species and the CO/H 2 O/O 2 system are highly pressure sensitive due to compositional changes in the radical pool. In addition, important radical recombination reactions are in the fall-off region between their lowand high-pressure limits at pressures and temperatures relevant for practical combustion applications.…”

“…Under fuel-lean conditions, a small percentage of the SO 2 is typically oxidized to SO 3 , which, at low temperatures, readily reacts with water to form sulfuric acid. In industrial power plants, this conversion of fuel sulfur to S(VI) (SO 3 and H 2 SO 4 ) leads to the deposition of corrosive condensates that adversely affect efficiency and durability [4]. Aircraft emissions of S(VI) have also received considerable interest as these species apparently serve as important precursors to sulfate aerosols [5].…”

Production of sulfate aerosol precursors in the turbine and exhaust nozzle of an aircraft engine

“…Indeed, several modeling studies suggest that <1%-2% gas-phase oxidation to H2SO 4 can be expected within the near-field plume (<10 ms to 1 s after emission) for a range of aircraft engine configurations, physical approximations, and chemical assump- As with oxidation outside of the engine, the extent of internal activity is uncertain. One ground-based measurement indicates sulfur oxidation of >0.4% at the early plume stage [Frenzel and ArnoM, 1994], and measurement of land-based, marine, and laboratory test gas turbines burning diesel fuel demonstrate oxidation to SO3 of between 2% and 22% [Harris, 1990]. Limited one-dimensional (i-D) modeling investigations have consistently pointed to significant sulfur activity within the engine, reporting up to 6% oxidation within the combustor for both aircraft [Brown et al, 1996b] and industrial applications [Hunter, 1982] and continued activity up to 6% oxidation depending on the amount of fuel sulfur assumed within the turbine and exhaust nozzle [Brown et al, 1996b].…”

Chemical ionization mass spectrometric measurements of SO2 emissions from jet engines in flight and test chamber operations

“…However, SO2 also reacts with atomic oxygen within the engine combustors to form SO3 [Harris, 1990]. Recent calculations of the ratio s : [SO31o/ [SOx]o, where the subscript o refers to exit plane concentrations and where SOx = SO2 + SO3, indicate that as much as 10% of SOx is emitted as SO3 [Brown et al, 1996a].…”