II International Symposium on Carbon for Catalysis ABSTRACTS

OP-I-10
NOVEL CARBON BASED CATALYST FOR THE REDUCTION OF NO WITH
COKE PETROLEUM ASHES AS ACTIVE PHASE: SYNTHESIS,
CHARACTERIZATION AND APPLICATIONS
Boyano A., Gálvez M.E., García-Bordejé E., Lázaro M.J., Moliner R.
Instituto de Carboquímica, CSIC, Miguel de Luesma Castán 4, 50018 Zaragoza, Spain
e-mail: xalicia@carbon.icb.csic.es
Selective catalytic reduction (SCR) in the presence of ammonia has become lately one of the
most outstanding technologies for the removal of nitrogen oxides. This process has been
widely studied, commercialised and successfully applied [1]. However, in the high
temperature range (300-500ºC) where commercial catalysts operate, SO 2 and particle
poisoning of commercial TiO 2 based catalysts are very serious drawbacks. To circumvent
these problems in NO x stationary sources, an attractive option is to place the SCR unit
downstream of the desulfuration device and particle removal equipment where both SO 2 and
ashes have been removed [2]. Since the temperature at this point is typically below 200ºC, it
is necessary to develop novel low-temperature SCR catalysts to avoid reheating of the flue
gas and thus decreasing the cost of the process.
With this objective in mind, a wide range of low-temperature SCR catalysts under different
forms and compositions have been prepared like powder catalysts (0.2-0.5mm), briquettes
(10.5x13.5 mm) and carbon-coated monoliths (10x50 mm). All these catalysts are based on
carbonaceous materials which are widely recognised as effective support precursors under
suitable operating conditions. The use of carbon as a support precursor presents advantages
over other catalysts like the simplicity of the preparation process, potentially low cost, easy
availability of coal, possibility of obtaining samples with proper geometry, good mechanical
resistance and finally an efficient performance at low temperature in the NO reduction.
For the preparation of the powder catalysts and the briquettes, a ground sieved Spanish lowrank
coal was used as carbon support precursor. In both cases, the coal was pyrolyzed and
subsequently activated with CO 2 or steam in a batch-mode fluidized bed reactor. The
monoliths were prepared by coating cordierite monoliths with a blend of two polymers, viz.
furan resin and polyethylene glycol (PEG). The coated monoliths were pyrolyzed and
56