Removal of Elemental Mercury from Simulated Flue Gas over Peanut Shells Carbon Loaded with Iodine Ions, Manganese Oxides, and Zirconium Dioxide
journal contributionposted on 28.11.2017, 00:00 by Jiawen Zeng, Caiting Li, Lingkui Zhao, Lei Gao, Xueyu Du, Jie Zhang, Le Tang, Guangming Zeng
A low-cost material with high adsorption and oxidation ability for Hg0 capture is needed, whereas it is hard to prepare by present methods. Here, halide ions (I–) and metal oxides (MnOx and ZrO2) were both loaded on peanut shells carbon to synthesize 6Mn-6Zr/PSC-I3. Various characterizations and experiments were used to investigate the physiochemical properties and Hg0 removal performances. The sample exhibited an abundant pore structure and the active components dispersed well on its surface. The excellent total Hg0 removal efficiency (more than 90%) was obtained in a wide reaction temperature range (150–300 °C) under a N2 + 6% O2 atmosphere. Moreover, the Hg0 adsorption capacity in 1440 min was 5587.0 μg·g–1 and the Hg0 oxidation efficiency after reaching adsorption equilibrium was more than 30%. Further, the reaction mechanism at 150 °C was proposed. The main chemical adsorption sites of carbon-iodine groups dominate Hg0 removal at the initial reaction stage. As reaction progresses, chemical adsorption is weakened due to the gradual saturation of adsorption sites, whereas catalytic oxidation caused by lattice oxygen and hydroxyl oxygen substitutes chemical adsorption and dominates Hg0 removal at the final reaction stage. Thus, the 6Mn-6Zr/PSC-I3 with economic and environmental benefits has a promising prospect in industrial applications.