https://nova.newcastle.edu.au/vital/access/ /manager/Index ${session.getAttribute("locale")} 5 https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:19400 tot), elemental (Hg⁰) and oxidized (Hg) mercury as well as SO₃ concentrations was obtained before and after the combustion rig's baghouse filter for in total 14 air and oxy-fuel experiments with 3 Australian coals. Based on this data, an assessment in respect to Hg oxidation, SO₂/SO₃ conversion and Hg and SO₃ capture on the test rig's filter was performed. The air and the oxy-fuel experiments with different extents of recycle gas cleaning, revealed differences in the Hg and SO₃ formation and capture behavior: the Hg/Hg^tot ratios in the flue gas are higher during oxy-fuel combustion compared to air-firing. This effect is even more pronounced at the filter outlet, after flue gas has passed through the filter ash. In some experiments, even a net oxidation of Hg⁰ entering the filter to Hg was observed. The Hg capture by ash in the baghouse filter has been found to reduce the Hg emissions considerably. However, the Hg capture was altered by the different oxy-fuel recycle configurations, leading to decreased Hg capture efficiencies on the filter for one of the coals. A coal-specific trend of increased SO₂/SO₃ conversion ratios with increased flue gas SO₂ levels was observed that could be related to the ash composition of the three different coals. This and the higher SO₂ concentrations in the flue gas lead to considerably higher SO₃ levels in oxy-fuel combustion with SO₂ recycling. During the experiments, also a considerable capture of SO₃ in the baghouse filter was observed (up to 80% under air- and up to 66% under oxy-fired conditions). A reduction of the SO₃ capture on the filter under oxy-fuel conditions may be related to the higher SO₃ levels in this process.]]> Wed 11 Apr 2018 13:19:47 AEST ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:20831 Sat 24 Mar 2018 08:05:53 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:20478 tot), elemental (Hg⁰), and oxidized (Hg²⁺) mercury concentrations was measured for various air and oxy-fuel combustion conditions. These data enable an evaluation of process parameters that influence the Hg emissions of an oxy-fuel combustion process. A theoretical mass balance between Hg fed to the process (fuel and Hg⁰ injection) and Hg measured before the filter matched well, indicating that no mercury was captured by fly ash at high temperatures. The capture of Hg⁰ and oxidized Hg²⁺ by ash in a baghouse filter has been determined for all experiments. Measured Hg concentrations show an increase when switching from air to oxy-fuel operation for all investigated coals and oxy-fuel settings, even when no additional Hg⁰ is injected to the oxidant gas. Moreover, the Hg²⁺/Hg^tot ratios in the flue gas are higher during oxy-fuel combustion. The Hg capture by ash in the baghouse filter has been found to reduce the Hg emissions considerably. Reduction rates in a range between 18 and 51% for air and between 11 and 29% for oxy-fuel combustion were observed.]]> Sat 24 Mar 2018 07:59:08 AEDT ]]> https://nova.newcastle.edu.au/vital/access/ /manager/Repository/uon:27365 Fri 21 Apr 2017 11:04:06 AEST ]]>