Energietechnik 4.0

On the Impact of Non‐CHO Elements on Fuel Properties in Waste Incineration

“…Experiments by Belo et al [16] have shown that homogeneous conversion of SO 2 to SO 3 is not relevant at temperatures below 900 °C, but the reaction can be catalyzed by fly ashes to obtain peak conversion rates at a temperature of about 700 °C. In typical combustion systems, the relevant 'stop temperature' is about 1000 °C, as suggested by Müller [17], but if fly ash with catalyzing components are present, as it is typically the case in waste incinerators, the resulting effective 'stop temperature' of can be lower, e.g., around 900 °C [12,18]. A further conversion of SO 2 into SO 3 even below this 'stop temperature' can occur in the presence of chlorine via the chlorine Griffin reaction: SO 2 + Cl 2 + H 2 O SO 3 + 2 HCl [9] (see also discussion in the next section).…”

“…The basic reaction sequence may be illustrated for chlorine: The primary product of combustion is HCl, which can be oxidized under fuel-lean conditions via HCl + (H,O,OH) → Cl + (H 2 ,OH,H 2 O) and subsequent recombination of Cl atoms to Cl 2 [15]. As suggested by Müller [17], a 'stop temperature' of about 1000 °C may be assumed, but if fly ash with catalyzing components is present, as it is typically the case in waste incinerators, the effective 'stop temperature' of the chlorine Deacon reaction (2HCl…”