Adsorption of gas-phase elemental mercury by sulphonitrided steel sheet. Effect of hydrogen treatment

Abstract Coal combustion, which is one of the most important energy sources of electricity generation, produces airborne pollutants: NO x , CO 2 , SO 2 , particulates and Hg°. A range of technologies is being developed to reduce the environmental impact of coal-fired power stations. No optimal technology that can be broadly applied exists as yet, but sorption of mercury is considered a promising approach. We report a novel adsorbent, which shows an extraordinary mechanical resistance and high adsorption capacity of mercury vapour. These adsorbent samples were synthesized in the gas sulphonitriding process using steel sheets. The chemisorption capacity of the sorbent materials, the process of the thermal desorption of mercury and the effect of the hydrogen activation treatment have been investigated in the work. It has been established that the capacity of mercury chemisorption increased more than twice after the heating treatment of the adsorbent in H 2 atmosphere at 500 °C in comparison with the non-activated one. The mechanism of activation has been elucidated in the paper. For the purpose of comparison, activated carbon was also investigated.