Annual Report 2006 - Plataforma Solar de Almería

PLATAFORMA SOLAR DE ALMERÍA
adequate for coating sensitive substrates. In addition stabilized suspensions
of commercial powdered TiO 2 will be also used for comparison. Dip-coating
and an innovative electrospray deposition technique will be utilized for photocatalysts
preparation. Photocatalytic activity and catalyst stability with each of
the different preparation variables will be studied for the degradation of three
representative organic pollutants: trichloroethylene, toluene and formic acid.
Achievements in 2006: CIEMAT activity during this period was mainly focused
on the synthesis of TiO 2 -coated materials of different porosity and transparency:
non-porous transparent supports, like borosilicate glass and organic
polymers (PET, cellulose acetate), and opaque ceramic substrates (natural
magnesium silicate plates calcined at different temperatures, which were prepared
in the ICP-CSIC), which present mesoporosity.
100
Conversion, %
90
80
70
60
50
3TiO 2 _G5_Sep800ºC
TiO 2 50_Sep50_500ºC
3TiO 2 _G5_porta350ºC
0 2 4 6 8 10
Area/F, s/cm
Figure 4.12
Trichloroethylene conversion as a function of the
illuminated area to flow ratio (Area/F) for three
different photocatalyts: TiO 2 coating on the silcate, a
50:50 W/w TiO 2 /silicate mixture and a TiO 2 layer on
a glass plate. Initial pollutant concentration 10 ppmv
An example of the of the efficiency of the obtained materials is shown in
Figure 4.12, which compare the performance of the same TiO 2 deposited as
layer on a porous ceramic or on a dense glass plate, with a bulk photocatalyst
formed by a mixture of TiO 2 and silicate. These results reveal that porosity is
beneficial for the TCE degradation but the TiO 2 coating is more efficient, very
likely due to a better exposure to the light. On the other hand, TiO 2 sol-gel
deposited on transparent supports, like those shown in Figure 4.11, have also
proved to be very efficient for VOC abatement. Nevertheless, polymeric supports
may suffer radiation damage and several strategies to increase their
durability have been tested, including the formation of a SiO 2 protective barrier
layer.
4.3.2 (DETOX-H2S)
Development of a new system for the elimination of air
borne toxic and corrosive compounds generated in sewage
treatment plants
Participants: CIEMAT, ICP-CSIC, ICV-CSIC and UNED (Spain); USACH (Chile)
and Univ. of Wisconsin (USA).
Contact:
Dr. B. Sánchez; benigno.sanchez@ciemat.es
Funding: CAM funded project, cost shared: 700 k€
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