One-step synthesis of renewable magnetic tea-biochar derived from waste tea leaves for the removal of Hg0 from coal-syngas

Elemental mercury (Hg-0) is becoming more alarming toxic pollutant due to its high persistence in the environment. However, advanced oxidation/adsorption techniques could be the major routes of Hg-0 removal by a suitable adsorbent. For this purpose, a highly competitive and regenerable magnetic tea biochar (MTBC) was developed by one-step pyrolysis of Fe(NO3)(3) laden waste tea leaves at 500 degrees C and characterized by analytical techniques such as BET, XRD, VSM, SEM, TGA, and XPS. The Hg-0 removal mechanism via adsorption/oxidation from simulated syngas was investigated under a wide reaction temperature range (60.-300 degrees C). Results revealed that the MTBC with an optimal loading of 0.46 mol/L Fe(NO3)(3), attained an approximately >= 95% of Hg-0 removal efficiency (eta(T)) at 180. under simulated syngas (10% CO, 10% H-2, and 400 H2S). The TBCFe 0.46 exhibited high H2O resistance under simulated syngas, although a slight decrease was received in.T at 10 vol% H2O. After six repeated adsorption/regeneration cycles, the eta(T) value was still above 90%. Consequently, the waste tea derived regenerable sorbent TBCFe 0.46 with high Hg-0 adsorption performance makes it an inexpensive, excellent recyclable catalyst to control mercury emission from coal syngas.