Removal of Mercury from Simulated Natural Gas by SO₂ Activated Petroleum Coke

Abstract A preparation method based on the carbon-thermal reduction reaction was proposed to make petroleum coke-based mercury adsorbent. The effects of activation agent flow rate, time and inlet mercury concentration on mercury removal were investigated. Mercury adsorption experiments were carried out on a fixed-bed reactor system under simulated natural gas atmosphere. Meanwhile, the mercury removal mechanism was put forward based on the characterization results, including surface area and micropore structure, element contents and active chemical functional groups. The results show that the raw petroleum coke (RPC) has almost no mercury removal capacity while the mercury removal efficiency of the sulfur activated petroleum coke (SPC) is greatly improved. After activation, specific surface area and micropores increased significantly. The sulfur content increased as well. Meanwhile, the relative content of non-oxidative sulfur forms and oxygen functional groups of SPC are significantly higher than RPC. The optimum parameters of activation agent flow rate and time of 100 mL/min and 1.5 h are reached in this experiment, respectively.