SO3/ Sulfur Condensables Measurement Technology
Breen Energy Solutions has developed a patented technology to measure the concentration and Dewpoint temperature of SO3 and other Sulfur derived condensable species in combustion flue gases.
Sulfur in fossil fuels oxidizes during combustion to form Sulfur-Dioxide (SO2). A portion of this SO2 further oxidizes to Sulfur-Trioxide (SO3). The SO2 to SO3 oxidation occurs in the furnace, across the ash deposits in the convective pass and across the Selective Catalytic Reduction (SCR) catalyst, if present for NOx removal. Typically, about 1% of the SO2 converts to SO3 in the furnace and convective pass. A further 0.5 to 3 % conversion can occur across the SCR subject to catalyst design and operating temperatures. The SO3 in the gas phase combines with moisture (H2O) to form Sulfuric Acid (H2SO4). This conversion starts at 800 DegF and is completed below 400 DegF where all the SO3 is now H2SO4. The H2SO4 can further react with elements and compounds such as Ammonia (NH3) to form Ammonium Bisulfate (NH4HSO4) and Sodium (Na) to form Sodium Bisulfate (NaHSO4) which are also condensable compounds. The H2SO4 may also react with Ash-Alkali to form non-condensing compounds such as Ammonium Sulfate, Sodium Sulfate, Potassium sulfate among others.
A condensable, by definition, is a compound that when presented with a surface that is at a temperature below its dewpoint will form a condensate on that surface. This dewpoint temperature is also called as the equilibrium dewpoint (DPe). However, in the presence of time-varying temperatures and gas velocity, the temperature at which these compounds condense can be considerably lower than the equilibrium dewpoint. We call this the Kinetic Formation Temperature (FTk). And the temperature necessary to completely re-volatilize any condensed deposits will be higher than the equilibrium dewpoint. We call this the Kinetic Evaporation Temperature (ETk).
The AbSensor - SO3/AbS measurement device measures the phenomenon of condensable condensation on a highly polished glass surface with embedded electrodes. As the temperature of this surfaces approaches the FTk, material condenses and the temperature is recorded. As this temperature is raised, it passes through the DPe, that temperature is also recorded. And finally as the temperature exceeds the ETk temperature, the deposit is vaporized as evidenced by the lack of current and this temperature is recorded.
The result of the measurement device is these three temperatures: FTk, DPe and ETk. From these device outputs further outputs are derived such as the SO3 concentration in PPM. These temperatures can then be used as an input to control strategies designed to solve plant BOP issues such as: SCR Minimum Operating Temperature (MOT), reduction of NH3 slip, Air Heater Fouling Mitigation, Average Cold End Temperature Control (ACET), Electo-Static Precipitator (ESP) Optimization, Blue Plume Mitigation and control of Alkali Injection systems for SO3 Mitigation.
Breen Energy Solutions has developed a patented technology to measure the concentration and Dewpoint temperature of SO3 and other Sulfur derived condensable species in combustion flue gases.Sulfur in fossil fuels oxidizes during combustion to form Sulfur-Dioxide (SO2). A portion of this SO2 further oxidizes to Sulfur-Trioxide (SO3). The SO2 to SO3 oxidation occurs in the furnace, across the ash deposits in the convective pass and across the Selective Catalytic Reduction (SCR) catalyst, if present for NOx removal. Typically, about 1% of the SO2 converts to SO3 in the furnace and convective pass. A further 0.5 to 3 % conversion can occur across the SCR subject to catalyst design and operating temperatures. The SO3 in the gas phase combines with moisture (H2O) to form Sulfuric Acid (H2SO4). This conversion starts at 800 DegF and is completed below 400 DegF where all the SO3 is now H2SO4. The H2SO4 can further react with elements and compounds such as Ammonia (NH3) to form Ammonium Bisulfate (NH4HSO4) and Sodium (Na) to form Sodium Bisulfate (NaHSO4) which are also condensable compounds. The H2SO4 may also react with Ash-Alkali to form non-condensing compounds such as Ammonium Sulfate, Sodium Sulfate, Potassium sulfate among others.
A condensable, by definition, is a compound that when presented with a surface that is at a temperature below its dewpoint will form a condensate on that surface. This dewpoint temperature is also called as the equilibrium dewpoint (DPe). However, in the presence of time-varying temperatures and gas velocity, the temperature at which these compounds condense can be considerably lower than the equilibrium dewpoint. We call this the Kinetic Formation Temperature (FTk). And the temperature necessary to completely re-volatilize any condensed deposits will be higher than the equilibrium dewpoint. We call this the Kinetic Evaporation Temperature (ETk).
The AbSensor - SO3/AbS measurement device measures the phenomenon of condensable condensation on a highly polished glass surface with embedded electrodes. As the temperature of this surfaces approaches the FTk, material condenses and the temperature is recorded. As this temperature is raised, it passes through the DPe, that temperature is also recorded. And finally as the temperature exceeds the ETk temperature, the deposit is vaporized as evidenced by the lack of current and this temperature is recorded.
The result of the measurement device is these three temperatures: FTk, DPe and ETk. From these device outputs further outputs are derived such as the SO3 concentration in PPM. These temperatures can then be used as an input to control strategies designed to solve plant BOP issues such as: SCR Minimum Operating Temperature (MOT), reduction of NH3 slip, Air Heater Fouling Mitigation, Average Cold End Temperature Control (ACET), Electo-Static Precipitator (ESP) Optimization, Blue Plume Mitigation and control of Alkali Injection systems for SO3 Mitigation.