Use of CuO/MgAl₂O₄ and La_0.8Sr_0.2FeO₃/γ‐Al₂O₃ in chemical looping reforming system for tar removal from gasification gas

Abstract

in Wiley Online Library (wileyonlinelibrary.com)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 /c-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 /c-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. Composition 40 wt % CuO, 60 wt % MgAl 2 O 4 (Baikowski S30CR) 10 wt %. La 0.8 Sr 0.2 FeO 3 , 90 wt % c-Al 2 O 3 (Puralox NWa155) Production parameters Spray drying, calcined for 4 h @ 10308C Impregnation, calcined for 2 h @ 11008C BET surface area (m 2 /g) 7.85 47.03

Experimental Investigation of Fe–Ni–Al Oxygen Carrier Derived from Hydrotalcite-like Precursors for the Chemical Looping Gasification of Biomass Char

“…Also, the mechanical strength and antisintering of the oxygen carrier need to be concerned . Up to now, metallic oxides including Cu, Fe, Co, Ni, and Mn − as well as nonmetallic oxides such as CaSO 4 , have been widely studied as oxygen and heat carriers in chemical looping combustion (CLC) or CLG process. Among them, Ni-based oxygen carriers have attracted much attention due to their higher redox activity and catalytic effect to decompose tar.…”

Utilization of Promising Calcium Manganite Oxygen Carriers for Potential Thermochemical Energy Storage Application

“…It is known that B-site dopant will have a higher impact than the A-site dopant on vacancy creation, which is related to the oxygen release ability of the compound . However, the effect of MgO addition to the B site was tested for a CLOU application. , A study revealed that MgO-doped CaMnO 3 showed good stability in a 50-cycle test and a small increase in reactivity was also observed . Both in thermal analysis and fluidized bed experiments (Figures and for CMM1 and CMM2, respectively), the reduction peak temperature was observed around 975–985 °C for both MgO-doped CaMnO 3 .…”

Chemical looping reforming: process fundamentals and oxygen carriers

“…Both supports and promoters have been tested to alleviate the sintering problem. The addition of inert supports such as Al 2 O 3 [133,[296][297][298], TiO 2 [133,297,299], and MgAl 2 O 4 [300] can slow down the sintering problem of copper oxide, but the addition of Al 2 O 3 , an acidic support, leads to the aggravation of carbon deposition [301]. As a result, Alirezaei et al [193] incorporated ZrO 2 into Al 2 O 3 , which promoted the dispersion of copper oxide and adjusted the mechanical properties of oxygen carriers.…”