Mercury content in woody biomass and its removal in the torrefaction process

Isotopic Fractionation Characteristics of Speciated Mercury from Local Biomass Combustion in the Tibetan Plateau

“…This result is partly explained by the fact that the Hg content of plant leaves is usually higher than that of plant stems, for leaves act as the major pathway of Hg uptake from air via leaf stomata. ,, Only the woody stem was used for wood combustion in this study, whereas grass leaves served as the major food source for yak with a dry matter digestibility of 55%, resulting in Hg accumulation in the produced dung . The Hg content of wood was within the range of concentrations measured in woody biomass (7.0 ± 6.6 to 12.4 ± 7.7 μg/kg) collected across China, ,, while the Hg concentrations of yak dung and wood were substantially lower than those previously reported for coal (260 ± 160 μg/kg). , …”

“…The emission ratios of Hg from yak dung and wood combustion varied in the range of 99.10–99.34%, implying that almost all the Hg stored in biomass is released into the atmosphere during combustion. The EF values of Hg from yak dung and wood combustion were 46.16 ± 29.93 and 8.91 ± 3.80 μg (Hg)/kg, respectively, which were considerably higher than prior reported values (0.1–4.5 μg (Hg)/kg). , In addition, the EF from local biomass combustion in the TP was far higher than those measured in industrial coal combustion emissions after the air pollution control device combinations of the electrostatic precipitator and wet flue gas desulfurization (1.19–1.54 μg (Hg)/kg) but was considerably lower than those from residential coal combustion (30.33–112.15 μg (Hg)/kg (coal)) with no air pollution control device …”

“…23,30,31 Only the woody stem was used for wood combustion in this study, whereas grass leaves served as the major food source for yak with a dry matter digestibility of 55%, resulting in Hg accumulation in the produced dung. 32 The Hg content of wood was within the range of concentrations measured in woody biomass (7.0 ± 6.6 to 12.4 ± 7.7 μg/kg) collected across China, 23,33,34 while the Hg concentrations of yak dung and wood were substantially lower than those previously reported for coal (260 ± 160 μg/ kg). 19,35 The emission ratios of Hg from yak dung and wood combustion varied in the range of 99.10−99.34%, implying that almost all the Hg stored in biomass is released into the atmosphere during combustion.…”

“…The EF values of Hg from yak dung and wood combustion were 46.16 ± 29.93 and 8.91 ± 3.80 μg (Hg)/kg, respectively, which were considerably higher than prior reported values (0.1−4.5 μg (Hg)/kg). 31,34 In addition, the EF from local biomass combustion in the TP was far higher than those measured in industrial coal combustion emissions after the air pollution control device combinations of the electrostatic precipitator and wet flue gas desulfurization (1.19−1.54 μg (Hg)/kg) 36 but was considerably lower than those from residential coal combustion (30.33−112.15 μg (Hg)/kg (coal)) with no air pollution control device. 37 For the combustion products (Figure 1b), the total concentrations of TGM and PBM emitted from yak dung combustion and wood combustion were 621.1 ± 236.0 and 173.3 ± 68.2 ng/m 3 , respectively, which were three to five orders of magnitude higher than the background ambient concentrations in the TP (1.3 ± 0.2 ng/m 3 for TGM and 48.7 ± 60.3 pg/m 3 for PBM).…”

Review and Perspectives on Mercury Release and Migration during Chemical Looping Combustion of Solid Fuels

“…As for biomass, some biomass contains an even higher level of mercury than coal. 69 In fact, biomass combustion is a significant source of atmospheric mercury pollution, accounting for more than 500 tons of global mercury emissions annually. 70 Therefore, the mercury issue of other solid fuels could not be overlooked.…”