MSW pyro-gasification using high-temperature CO2 as gasifying agent: Influence of contact mode between CO2, char and volatiles on final products

•MSW pyro-gasification performed with HT-CO2 gasifying char and volatiles.•Contact modes of HT-CO2, char and volatiles assessed to capitalize on char catalyst.•The maximum gas yield of 0.71 Nm3/kgMSW and highest CGE obtained in M3.•The char contacting HT-CO2 alone firstly in M3 contributed its highest activity.•HT-CO2 and volatiles contact must be delayed when design a reforming reactor.