2.2. Procedures
The test solution used for this experiment was a 1.6 m (molal:
mol kgH2O1
) total NH3, 0.2 m SO4
2, pH 10 solution (2.4 wt.%
NH3 and 2 wt.% H2SO4). This solution is consistent with the inorganic
concentrations in the feed which led to the SCWO reactor
failure described in the introduction. The flow rate of the ammoniacal
solution was 15 mL/min. Oxidant was delivered in the form of
hydrogen peroxide (H2O2). Homogeneous peroxide decomposition
occurs readily in ammoniacal alkaline solutions especially as temperature
is increased – the half life of hydrogen peroxide is approximately
9 min in 1.9 M NH3 at 80 C [5]. Heterogeneous catalysis of
hydrogen peroxide decomposition on Fe oxides is also known to
0