For achieving CO
2 thermal reduction, a technology combining solid carbon activation and high-temperature CO
2 reduction was proposed, named as activated-reduction technology. In this study, this technology is realized by using a circulating fluidized bed and downdraft reactor. Reduced agent parameters (O
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For achieving CO
2 thermal reduction, a technology combining solid carbon activation and high-temperature CO
2 reduction was proposed, named as activated-reduction technology. In this study, this technology is realized by using a circulating fluidized bed and downdraft reactor. Reduced agent parameters (O
2/C and CO
2 concentration) greatly affect the reduction effect of CO
2. In addition, the effect of the activation process on different carbon-based materials can help to broaden the range of carbon-based materials used for CO
2 reduction, which is also an important issue. The following three points have been studied through experiments: (1) the influence of the characteristics of the reduced agent (CO
2 concentration and O
2/C) on CO
2 reduction; (2) the performance of different chars in CO
2 reduction; and (3) the activation effect of solid carbon. The activation process can develop the pore structure of coal gasification char and transform it into activated char with higher reactivity. The CO concentration in the tail gas is a crucial factor limiting the effectiveness of CO
2 reduction, with an experimentally determined upper limit of around 55% at 1200 °C. If CO concentration is far from the upper limit, temperature becomes the significant influencing factor. When the reduced agent O
2/C is 0.18, the highest net CO
2 reduction of 0.021 Nm
3/kg is achieved at 60% CO
2 concentration. When the reduced agent CO
2 concentration is 50%, the highest net CO
2 reduction of 0.065 Nm
3/kg is achieved at 0.22 O
2/C. Compared with CPGC, YHGC has higher reactivity and is more suitable for CO
2 reduction. The activation process helps to reduce the differences between raw materials.
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