A sulfur-resistant CuS-modified active coke for mercury removal from municipal solid waste incineration flue gas

Adsorption is a typical method for air pollutant removal from flue gas. A CuS-modified active coke (CuS/AC) sorbent was developed to improve the elemental mercury removal efficiency from municipal solid waste incineration (MSWI) flue gas. The influences of the loading amount of CuS, reaction temperature, and flue gas components including O₂, SO₂, H₂O, and HCl on Hg⁰ removal efficiency were investigated, respectively. The results showed that the mercury adsorption capacity of CuS/AC_(20%) sorbent was about 7.17 mg/g with 50% breakthrough threshold, which is much higher than that of virgin active coke. The analysis of XPS indicated that HgS was the main species of mercury on spent CuS/AC, which implied that adsorption and oxidation were both included in Hg⁰ removal. S₂²⁻ played a vital role in the oxidation of physically adsorbed Hg⁰. Meanwhile, the common components of MSWI flue gas exhibited no significant inhibition effect on Hg⁰ removal by CuS/AC sorbent. CuS/AC sorbent is a promising sorbent for the mercury removal from MSWI flue gas.