Mercury Control and Mercury Stability in Byproducts - Mercury Emission and its Control in Chinese Coal-Fired Power Plants - page 106

needful to obtain an economic and efficient adsorbent for mercury control in the
coal-fired flue gas.
Through experiments on sorbents and chemically modified sorbents, those with
good Hg 0 adsorption abilities were identified. These include activated carbon (AC),
AC-MnO 2 , ZS-MnO 2 , PT-MnO 2 , FS-MnO 2 , AC-FeCl 3 , ZS-FeCl 3 , and activated
carbon treated by sulphurization at different temperatures (AC-S).

5.3.1 Hg 0 Adsorption Ability of Normal Sorbents

The Hg 0 adsorption ability of fly ash, calcium-based sorbents (hydrated lime, lime,
MFC), zeolite, bentonite, vermiculite, bimomass semicoke, activated carbon, etc.
were studied on the bench-scale test of the mercury controlling mechanism in
simulated flue gas (BL).

5.3.1.1 Hg 0 Adsorption Ability of Fly Ash

Fly ash can remove some mercury from coal-fired flue gas through adsorption.
Carbon-in-ash is one of the factors influencing Hg 0 adsorption by fly ash. Experi-
ments were conducted under the same conditions (Hg 0 concentration: 19.4 g/m 3 ;
simulated gas: BL; temperature: 125 °C; flow: 1 L/min; fly ash: 70 mg). The ad-
sorption kinetic curves of Hg 0 by 3 kinds of fly ash (FA, LFA1 and LFA2) with
different carbon content are shown in Fig. 5.2.

5

FA

LFA1

LFA2

4

3

2

1

0

0 10 20 30 40 50 60 70

Time (min)

Fig. 5.2 Hg 0 adsorption by three kinds of fly ash
According to a previous research, the mercury adsorption ability of fly ash is
related to its carbon residue content; however, carbon content alone cannot deter-
mine the mercury adsorption ability of fly ash [14] . As shown in Fig. 5.2, the Hg 0