Use of CuO/MgAl₂O₄ and La0.8Sr0.2FeO₃/γ‐Al₂O₃ in chemical looping reforming system for tar removal from gasification gas

Biomass gasification gas contains condensable hydrocarbons usually referred to as “tars.” The use of chemical‐looping reforming (CLR) has been proposed as a downstream technology for tar removal. The tar removal capabilities and the regeneration properties of two particularly promising bed materials, CuO/MgAl 2 O 4 and La 0.8 Sr 0.2 FeO 3 /γ‐Al 2 O 3 , were investigated using C 2 H 4 , C 6 H 6 , and C 7 H 8 as tar surrogates. The material La 0.8 Sr 0.2 FeO 3 /γ‐Al 2 O 3 exhibited high levels of conversion of all tar surrogates investigated, whereas CuO/MgAl 2 O 4 showed less promising behavior. For this material, the C 2 H 4 conversion in the absence of aromatic compounds was very high, but in the presence of monoaromatic compounds, the conversion of aromatics and C 2 H 4 was poor. This indicates that monoaromatic compounds hinder the conversion of C 2 H 4 effectively. Therefore, C 2 H 4 may not always be a good choice as a tar surrogate and its suitability may depend on the mechanism of hydrocarbon conversion on the bed material surface in question.