The powder flow was influenced by carrier gas in the unit operation, such as pneumatic conveying and hopper discharge, in the pressurized entrained flow gasification technology. Carrier gases play a vital role in fluidization/ defluidization of powders. In this paper, we investigate the fluidization/ defluidization of absorbent Fluid Catalytic Cracking (FCC) and non-absorbent glass bead with two different carrier gases, N-2 and CO2. The flowability of aerated powders with different carrier gases were obtained in the fixed bed region whose superficial gas velocity was lower than minimum fluidization gas velocity and fluidization region. The powder flowability was characterized by basic flow energy, flowability rate index and aeration energy with the help of FT4 powder Rheometer. The influence of different carrier gases on fluidization/ defluidization of powder bed was further discussed. Transition line of A/C powders with different carrier gases was revealed. Effect of gas type and inter-particle force were calculated, compared with the flowability of aerated powder bed. In addition, combined with bed stress analysis, different bed fluidization mechanism with different gas velocities were revealed. Our findings might help people understand the influence of carrier gases on the fluidization/ defluidization of powders in the relative chemical unit operations. (C) 2020 Elsevier B.V. All rights reserved.