Binary mineral sulfides sorbent with wide temperature range for rapid elemental mercury uptake from coal combustion flue gas

Developing efficient sorbents with rapid kinetics is the main challenge encountered for Hg-0 capture from coal combustion flue gas in a sorbent injection scenario. Binary mineral sulfide-based materials combining copper sulfide (CuS) and zinc sulfide (ZnS) to exert their capabilities for Hg-0 capture at the low- and high-temperature was for the first time reported for Hg-0 removal to realize a wide temperature range sorbents. When the molar ratio between CuS and ZnS was 10%, the as-synthesized 10Cu-Zn nanocomposite exhibited excellent Hg-0 uptake rate at 150 degrees C that could degrade 40 mu g/m(3) of Hg-0 to undetectable level at the end of a 60-s experiment with the dosage of only 1 mg. This Hg-0 uptake rate is folds higher compared to that when bare CuS or ZnS was adopted alone at this specific temperature. The typical flue gas atmospheres had negligible effect on Hg-0 removal over 10Cu-Zn in a short contact time, which further suggests that the binary sorbents were proper to be injected before the electrostatic precipitator system. Moreover, it is found that, by adjusting the ratio between CuS and ZnS, it is potential to develop binary sorbent suiting any temperature conditions that may achieve an exceedingly high Hg-0 capture performance. Thus, this work not only justified the candidature of 10Cu-Zn as a promising alternative to traditional activated carbon for Hg-0 capture from coal combustion flue gas but also guided the future development of multi-component mineral sulfide-based sorbents for Hg-0 pollution remediation from various industrial flue gases.

Automated summary

Developing efficient sorbents with rapid kinetics is the main challenge for Hg-0 capture from coal combustion flue gas. A binary mineral sulfide-based material combining copper sulfide and zinc sulfide was reported for the first time for Hg-0 removal over a wide temperature range, showing promising potential as an alternative to traditional activated carbon for Hg-0 capture.