The catalyst consisted of a metallic monolith, onto which a Pt/
Al2O3 active phase was wash-coated. As with analogous catalysts
used for automotive application, the catalyst was housed in a container
with matting to provide vibration resistance. The catalyst
was divided into two equivalent sections.
The seawater scrubber contained three main abatement sections:
a Venturi scrubber for PM abatement and two tray towers
to promote intimate contact between the gas phase and the scrubbing
water. The first of these towers was designed mainly for
abatement of gas phase species (SOx and NOx). In fact, the exhaust
gas was emitted from the system at this stage, through the use of
an extractor fan. The second tray tower was designed for oxidation
of aqueous species, such as SO2 dissolved in the scrubbing water,
by the addition of air.
The pilot-plant set-up and piping is illustrated schematically in
Fig. 2. Measurement points for various parameters – gas phase
composition, temperature, pressure, gas flow and water flow –
were positioned throughout the system.