The need to capture CO2 emission, the major factor in global warming, from stationary plant is crucial for Malaysia. Cement manufacturing contribute a significant amount of this emission due to its calcination process of the limestone. In this study, this CO2 emission was used to activate the oil-palm shell (OPS), which is an abundance waste from palm oil refinery plant. The efficiency of the C-CO2 reaction of the synergetic process was calculated to determine the amount of CO2 emission being used in activating the OPS. The carbonized OPS was heated with CaCO3 in the furnace. The remaining CaCO3 and the generated oil palm shell activated carbon (OPSAC) weight were measured. The column test was used to determine the adsorption capability of the generated OPSAC. It was found that the CO2 is released slowly at higher than permissible calcination temperature of 848 oC and increased rapidly as the temperature increased. High C-CO2 reaction efficiencies above 70 % are attained at 850 oC or with equal weight ratio between CaCO3 and carbonized OPS. The highest experimental adsorption capability at 31.38 mg/g was achieved using 45g CaCO3 at 950 oC, compared to 18 mg/g using commercial activated Oil Palm Shell activated carbon (OPSAC). The Scanning Electron Microscopy (SEM) verified the increment of the pore area thus the surface area of the generated activated carbon. The experiment proved that the CO2 emission from the calcination can be eliminated by activating the oil palm shell waste.