Chemical-looping auto-thermal reforming of biomass using Cu-based oxygen carrier

Highlights: • Using Cu-based OC (oxygen carrier) in CLR of biomass is feasible, with heat balance in fuel reactor. • The presence of Cu-based OC can evidently promote the biomass conversion. • The presence of Cu-based OC is beneficial to tar removal and C₂H_m decrease. - Abstract: Chemical-looping reforming (CLR) of biomass, which utilizes active lattice oxygen from oxygen carrier (OC), provides a novel route to convert biomass into synthesis gas. This research utilized Cu-based OC rather than commonly-used Fe- or Ni-based OC in the process. The possible advantage is the exothermic reactions between CuO and gasification products are beneficial to auto-thermal reforming of biomass in fuel reactor. Batch fluidized bed experiments with different carriers (silica sand, Fe-based or Cu-based OCs) were conducted at different temperatures. It was found that when using Cu-based OCs, the gas yield and carbon conversion efficiency increased significantly, but the gasification efficiency and low heating value decreased accordingly, which are ascribed to the high-reactivity Cu-based OCs prompt the carbon conversion and also consume more reducible gases. The presence of Cu-based OCs help reduce C₂Hm and tar in syngas. Additionally, the tar content decreased with temperature increase, while C₂H_m content first increased then decreased.