Abstract Relationships between char preparation conditions and CO 2 -gasification conversions have been examined using a wire-mesh, a fluidised-bed and a ‘hot-rod’ (fixed-bed) reactor. Conversions from the direct gasification of untreated coal have been compared with those from the gasification of chars prepared: (i) in-situ under helium in each reactor, before switching over to CO 2 ; and (ii) from gasification in all three reactors of a char sample, pre-prepared in the fixed bed reactor. Conversions from direct gasification were slightly higher than experiments where samples were first pyrolysed in situ and gasified under CO 2 in the same reactor. In some cases, conversions were within experimental error. Under these conditions and within several percentage points, the pyrolysis and gasification steps may be considered as additive. Lower overall conversions observed in the hot-rod reactor have been attributed to the combined effect of: (i) formation of a low reactivity char—owing to tar-solids contact leading to secondary char deposition; and (ii) poor contact between char and the reactive gas. In the wire-mesh and the fluidised-bed reactors, direct CO 2 -gasification conversions were considerably larger than those determined using the common sample of char, pre-prepared in the hot-rod (fixed-bed) reactor. This sharp drop in overall conversion shows that care must be taken in interpreting reactivity data from ‘two-reactor, two-step’ procedures where char preparation conditions are not identical to those of the gasification step. A broadly linear relationship has been observed between conversions from a pilot plant reactor and direct CO 2 -gasification in the bench-scale high-pressure wire-mesh reactor. Despite differences between operating parameters in the two reactors, the results suggest that data from the wire-mesh reactor may be successfully used to compare relative coal reactivities under pilot-plant gasification conditions.