Fluid Catalytic Cracking (FCC) unit is a process of cracking heavy oil products into light high value-added products. Usually, atmospheric and vacuum oil products produced by atmospheric and vacuum distillation units of refinery are used as raw materials of the FCC unit, and which are creaked into high value-added products such as Liquefied Petroleum Gas (LPG), gasoline and diesel oil at high temperature. In the cracking process, dry gas and slurry of low value-added products are also formed, and some raw materials become coke during cracking, which burns and generates heat during catalyst regeneration.