Powder and Monolith-Supported Sulphur Trap Materials Based on Modified Hydrotalcite-Derived Supports

Abstract

SO x traps were prepared using hydrotalcite materials of different composition and their SO x storage properties were monitored during temperature cycling (50-600°C) under continuous feed streams (50 ppm SO 2 , 6 vol.% O 2 , 5 vol.% CO 2 , 100 ppm NO) at a space velocity of 144,000 L/(kg h). A comparison is made with non-hydrotalcite mixed oxide supports as well as pure alumina. The most promising material NaMnO x /Al 2 O 3 was wash-coated on a cordierite core and its SO x trap capacity was compared with the performance of the powder and the slurry. The slurry as well as the monolith-supported material showed an SO 2 uptake of 93% over 7 h time-onstream corresponding to 20 wt.% sulphate. DRIFT spectroscopy revealed the prevailing sulphate formation on Mn-related sites and Na. Regeneration of the trap with CO/ H 2 (k = 0.99) at 600°C was not completely possible.