Abstract :
[en] Emissions of Volatile Organic Compounds (VOCs) are one of the greatest contributors to air pollution. They are responsible for several environmental problems, such as the ozone layer depletion and the formation of tropospheric ozone, while also being dangerous to human health. Since legislation has restricted the limits for VOC emissions, the existent abatement techniques must be improved to meet the new requirements. Among these, catalytic oxidation is a well-known technique in which the VOC is oxidized into CO2 and water, using one of two types of catalysts: supported noble metal and metal oxide-based catalysts. Although the former presents higher activity, the availability and low cost of the latter make them a suitable and energetically advantageous alternative.
While many studies are made in the development and test of new materials, the majority is performed at laboratory scale only. [1]. To assess viability for industrial applications tests of mixtures at pilot scale are required. In this work the performance of a mixed oxide catalyst Co-Al-Ce (pellets) [2] is studied at a pilot scale unit (reactor volume: 0.5 L ; 400.7 g of catalyst) for the oxidation of n-Butanol and Toluene and their mixtures which are representative of automobile industry emissions . Light-off curves were obtained for concentrations between 1000 and 2000 ppm and air flowrates of 22 and 44 NL/min (Figure 1). The catalyst enables complete oxidation of n-Butanol at low temperature (230°C), while providing a very good selectivity for Toluene's oxidation. Three mixtures were studied using an air flow rate of 44 NL/min (Figure 2). It was found that the presence of n-Butanol promotes the oxidation of Toluene.
References:
[1] H. Sedjame et al., 'Applied Catalysis B : Environmental On the promoting effect of the addition of ceria to platinum based alumina catalysts for VOCs oxidation,' 'Applied Catal. B, Environ., vol. 144, pp. 233-242, 2014.
[2] J. Brunet et al., 'Co-Al-Ce Mixed Oxide Materials Prepared by Hydrotalcite Way for VOCs Total Oxidation in Micro- and Semi-Pilot Scale,' Mater. Today Proc., vol. 3, no. 2, pp. 188-193, 2016.
