Granular-bed filtration was investigated theoretically
and experimentally with the view to its applicability to
gaseous trace element removal at high temperatures.
Granular-bed filters have received a great deal of
attention recently as an alternative to the more
conventional gas cleanup devices such as cyclones,
electrostatic precipitators (ESP) and bag-filters. None
of these conventional devices is capable of operating
efficiently at high temperatures, (800-900 °C) typical of
combined cycle power generation plants. Moreover, a
sizeable proportion of the volatilised trace metals will
exit from the reactor in the vapour phase and these
purification devices are not generally designed to remove
the gaseous species.
In an atmospheric test rig, trace elements of concern
were removed in a fixed granular-bed filter at 800-900 °C
temperature range using sorbent particles (such as
limestone) as the unbonded filter medium. Two
configurations of the experimental apparatus were
employed to enable an accurate determination of the
removal efficiency of various sorbent particles.
The results show that volatilised trace elements can be
effectively removed from hot flue gases by passing them
through a fixed bed of suitably selected solid sorbents.
Removal efficiencies of higher than 99 % were achieved
with solid sorbent particles in the 0.3-3.0 mm size
range, operating at 800-900 °C.
|Place of Publication||Espoo|
|Publisher||VTT Technical Research Centre of Finland|
|Number of pages||78|
|Publication status||Published - 1989|
|MoE publication type||D4 Published development or research report or study|
|Series||Valtion teknillinen tutkimuskeskus. Tutkimuksia - Research Reports|
- hot gas cleanup
- trace elements
- granular bed filters