The CaO-based pellets were fabricated using extrusion-spheronization method for calcium looping thermochemical heat storage under the fluidization. The effects of adhesive

biomass-based pore-forming agent

binder and particle size on the heat storage performance and mechanical property of the CaO-based pellets were investigated in a bubbling fluidized bed reactor. The addition of 2% (mass) polyvinylpyrrolidone as an adhesive not only helps granulate

but also improves the heat storage capacity of the pellets. All biomass-templated CaO-based pellets display higher heat storage capacity than biomass-free pellets

indicating that the biomass-based pore-forming agent is beneficial for heat storage under the fluidization. Especially

bagasse-templated pellets show the highest heat storage conversion of 0.61 after 10 cycles. Moreover

Al

2

O

3

as a binder for the pellets helps obtain high mechanical strength. The CaO-based pellets doped with 10% (mass) bagasse and 5% (mass) Al

2

O

3

reach the highest heat storage density of 1621 kJ·kg

-1

after 30 cycles and the highest crushing strength of 4.98 N. The microstructure of the bagasse-templated pellets app

ears more porous than that of biomass-free pellets. The bagasse-templated CaO-based pellets doped with Al

2

O

3

seem promising for thermochemical heat storage under the fluidization

owing to the enhanced heat storage capacity

excellent mechanical strength

and simplicity of the synthesis procedure.