Physical properties and reactivity of char obtained from downdraft gasification of sorghum and eastern red cedar

•Studied properties and reactivity of downdraft gasification-based char.•Downdraft gasifier produced char with higher quality than fluidized-bed gasifier.•Micropores and mesopores were dominant in both sorghum and red cedar chars.•Sorghum char contained more aromatic carbon than red cedar char.•The gasification reactivity of red cedar char was higher than that of sorghum char.