Mercury and SO3 measurements on the fabric filter at the Callide Oxy-fuel Project during air and oxy-fuel firing transitions. (April 2016)

• Record Type: Journal Article
• Authors: Stanger, Rohan; Belo, Lawrence; Ting, Timothy; Spero, Chris; Wall, Terry
• Is Part Of: International journal of greenhouse gas control. Volume 47(2016:Apr.)
• Page Start: 221
• Page End: 232
• Publication Date: 2016-04
• Subjects: Oxy-fuel combustion -- Mercury -- Fabric filter -- SOx; Greenhouse gases -- Environmental aspects -- Periodicals; Air -- Purification -- Technological innovations -- Periodicals; Gaz à effet de serre -- Périodiques; Gaz à effet de serre -- Réduction -- Périodiques; Air -- Purification -- Technological innovations; Greenhouse gases -- Environmental aspects; Periodicals; 363.73874605
• DOI: 10.1016/j.ijggc.2016.01.049
• Languages: English
• ISSNs: 1750-5836

Abstract

Highlights: Mercury and SO3 emissions were measured at the Callide Oxy-fuel Project. Measurements were taken during transitions between air and oxy-firing. The use of low NO x burners significantly reduced mercury emissions. Mercury capture rates were estimated at 92–99% in oxy-firing. Low SO3 values were suggested due to acid condensation in a prior heat exchanger. Abstract: The Callide Oxy-fuel Project is the world's largest operating oxy-fuel plant. This work details an experimental test campaign at the Callide Oxy-fuel Project monitoring mercury and SO3 levels exiting the fabric filter during transitions between air and oxy firing conditions. The measurements were taken using two custom built probes; the first allowing combined collection of SO3 and mercury over short time intervals; the second allowing on-line measurements of Hg total and Hg 0 with SO x removal. Total mercury emissions in oxy-firing measured a maximum of 6–7 μg/m 3 of which 89% was in oxidised form (Hg 2+ ). The use of low NO x burners had an overriding influence on the mercury measurements reducing the total mercury levels to 0.13 and 0.15 μg/m 3 (air, oxy respectively) with no Hg 2+ being measured. The SO3 concentrations were also lower than expected, estimated at ∼0.5–0.8 ppm (based on a practical estimate of 1% conversion of SO2 ). Overall mercury capture in either operating mode was estimated at 92–93% for the existing burners and 98–99% with the low NO x burners used (being 2 of the 4 burners operating). Total SO x captured from the flue gas was 16% in oxy-mode and 19% in air firing. These findings suggest that operational conditions have a primary impact on capture of Hg and SO x during transitions with a secondary impact of firing mode (i.e. air or oxy).