The production of activated carbon is influenced by several factors that may affect its characteristics such as particle size, temperature and heating rate. Activated carbon exhibits a large surface area and very narrow pores. If you expose bodies of activated carbon of a size of some mm's to a flow of carbon dioxide, it will take you unmeasurable periods of time to replace the gas atmosphere within the narrow pores with carbon dioxide and remove the oxygen. The synthesis of activated carbon is generally divided into two main pathways: (1) physical and (2) chemical activation. These two methods are often influenced by the type of chemical activator used during the production, impregnation time, carbonization temperature and duration, chemical composition. The latter strongly depends on the activating agent (carbon dioxide, air or steam) But air and oxygen avoided because Oxygen in the purge gas reduces the life span of activated carbon. Increasing regeneration temperature can increase heel build-up on activated carbon. The pore structure can collapse and the surface area can seriously have decreased when the oxygen content of pitch precursor is too high however oxygen has faster reaction kinetics with carbon than steam and carbon dioxide, the addition of oxygen as an activation agent had been found to be more efficient to reduce the processing time

It is an uneconomical process and requires studies and experiments on air pollution