Reduction in Dioxin Emissions by the Addition of Urea as Aqueous Solution to High-temperature Combustion Gas

Effects of gaseous NH3 and SO2 on the concentration profiles of PCDD/F in flyash under post-combustion zone conditions

“…However, some mechanisms also involve the reaction of the nitrogen-based additives and their degradation products with PCDD/F precursors. For example, during combustion NH i and CN radicals may form and can become attached to potential aromatic rings or may even be inserted into the rings forming aromatic amines, nitriles and pyridine-like structures (Kasai et al, 2008). Recently, Marie-Rose et al (2009) proposed that PCDD/F could be removed from flue gas via oxidation by NO 2 , produced from the prior oxidation of the ammonia additive.…”

“…These could include the type and configuration of plant (Addink et al, 1996), the concentration and form of application of the particular additive (Furrer et al, 1998;Bechtler et al, 1998;Ruokojarvi et al, 2004;Kuzuhara et al, 2005), the point of application within the plant (Kasai et al, 2008), the operating temperature of the plant (Jansson, 2008;Weber et al, 1999;2002;Lundin, 2007;Cunliffe and Williams, 2007) as well as composition of the fuels.…”

Modeling Sintering Process of Iron Ore

“…Finally, this scenario was compared with the actual operation with regard to the emissions of dioxin (PCDD-Poly Chlorinated Di-benzene Dioxin) and furans(PCDF -Poly Chlorinated Di-benzene Furan). The sintering process have been strongly requested to reduce polychlorinated substances emissions, therefore, new technologies need to be compared not only from the point of view of economics but also from the environmental load (Castro et al 2005, Cieplik et al 2003, Kasai et al 2008. Figure 9 and 10 show the comparisons of PCDD and PCDF distributions within the sinter strand for actual operation and case 6.…”

“…In addition, in this machine concept , part of the process gas is reutilized in a pre-combustion chamber with natural gas with ignition burners to keep heat supplying on the surface of the sinter strand and enlarge the heat affected zone. The physicochemical and thermal phenomena involved in this process are complex and numerous ( Nakano et al, 2010, Kamijo et al 2009, Kasai et al 2008. Special mention is made to the phenomena of gas flow through the porous bed, gas-solid heat transfer, drying, vaporization and several chemical reactions and phase transformations (Umekage et al 2009, Cieplik, 2003, Cores et al 2010.…”

Recent Research Trends on the Dioxin Emissions in High Temperature Process

“…Effect of urea addition to the splayed water of cooling tower of a solid waste incinerator on the toxic concentration of dioxin in the waste gas 18) .…”