Low-temperature catalytic conversion of lignite: 2. Recovery and reuse of potassium carbonate supported on perovskite oxide in steam gasification

Catalytic recovery after repeated uses of unsupported K2CO3 or K2CO3 supported on 3 kinds of perovskites (LaMn0.8Cu0.2O3, LaMn0.8Cu0.2O3/γ-alumina, and La0.9K0.1MnO3) was investigated during steam gasification of an Indonesian lignite (Adaro) at 700 °C. Perovskite supports effectively retained K2CO3 and maintained higher catalytic activity than K2CO3 alone. The supported catalysts were recovered from the ash after gasification based on their size and ferromagnetism. Quartz and alumina accumulation on the catalyst poisoned the ash due to reactivity with potassium. Catalytic activity as high as 90% carbon conversion was maintained up to seven cycles, and separation from the ash after gasification regenerated the activity.