Effects of Coal-Fired Flue Gas Components on Mercury Removal by the Mechanochemical S-Modified Petroleum Coke.

In this work, the effects of coal-fired flue gas components (O, CO, SO, and NO) on the Hg removal by the promising mercury removal adsorbent mechanochemical S-modified petroleum coke were characterized and analyzed in terms of the Hg removal efficiency, mercury adsorption capacity, and mercury mass balance. The results show that the mechanochemical S-modified petroleum coke with a theoretical sulfur content of 21% (named TSC-21) is the best candidate for mercury removal based on the Hg removal efficiency, Hg removal capacity, and difference ratio of Hg removal capacity (anti-interference ability) in the basic and full-component simulated flue gas atmosphere (N + O + CO, N + O + CO + SO + NO). The maximum value (MV) and stable value (SV) of the Hg removal efficiency of TSC-21 in the basic simulated flue gas atmosphere are 99.25% (MV) and 91.17% (SV), respectively. O, CO, and NO all promote the Hg removal by the adsorbent, but they benefit the Hg oxidation while inhibiting the Hg adsorption. The promoting effect of O on the Hg removal by TSC-21 is affected by the reaction time, which is especially obvious after 1 min. The presence of SO inhibits the oxidation and adsorption of Hg, which in turn reduces the Hg removal performance of the adsorbent. The improving effects on the oxidative escape of Hg by CO is higher than that by NO and O. TSC-21 acts more as an oxidant than an adsorbent for Hg removal.