Mercury emissions from industrial sources in China

Transcription

1 Mercury emissions from industrial sources in China Xinbin Feng 1, David Streets 2, Jiming Hao 3, Ye Wu 3, Guanghui Li 1 1 State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences 2. Decision and Information Sciences Division, Argonne National Laboratory, Argonne, IL 60439, USA 3. Department of Environmental Sciences and Engineering, Tsinghua University, Beijing , China

2 Major industrial sources in China Fuel oil for stationary sources (e.g., power plants, industrial use) Gasoline, diesel and kerosene Biofuel combustion Grassland/ savanna burning Waste and residue burning Cement production Iron and steel production Caustic soda production Non-ferrous metal smelting (Zn, Pb, Cu, and Au) Mercury mining Battery and fluorescent lamp production.

3 Model used to calculate mercury emissions from different industrial sources (Streets et al., 2005) Et= [ef i,j,t A i,j,t F RELj,t (1-F REMj,t )] (1) i j where Et is the mercury emission; ef i,j,t is emission factor for other fuels or noncombustion processes; A i,j,t is the amount of fuel consumption or production yield of noncombustion processes; F RELj,t is the fraction of mercury to the atmosphere; F REMj,t is the fraction of mercury removed by emission control devices; j is the combustor type with/without control devices; i is the province; and t is the year.

4 Mercury emission factors from industrial sources in China Studies on mercury emissions from industrial sources are rare in China. Mercury emission factors from most source categories were obtained according to measurement date conducted in Europe and North America.

5 Case studies on mercury emissions from industrial sources in China Mercury emission from artisanal mercury smelting Mercury emission from artisanal zinc smelting Mercury emission from large scale zinc smelting

6 Case studies on mercury emissions from industrial sources in China Mercury emission from artisanal mercury smelting Mercury emission from artisanal zinc smelting Mercury emission from large scale zinc smelting

7 Artisanal mercury smelting site in Wuchuan

8 The procedure of mercury smelting

9 Final product-liquid mercury

10 Smelting residues

11 F ( O S) W P 10 6 P 100% F: mercury emission factor (%) O: Hg concentration in ore (mg/kg) S: Hg concentration in calcine (mg/kg) W: Total consumption of Hg ore per day (kg) P: Daily mercury production (kg)

12 Mercury emission factors in different mining areas in Wuchuan (Li et al., 2008) Site O (mg/kg) S (mg/kg) W (kg) P (kg) F (%) YQG LX TB Average 20.5

13 Annual Hg emission in Wuchuan Hgmining areas (Li et al., 2008) Site YQG LX TB Total Number of furnaces Annual Hg production (t) Annual Hg emission (t)

14 Case studies on mercury emissions from industrial sources in China Mercury emission from artisanal mercury smelting Mercury emission from artisanal zinc smelting Mercury emission from large scale zinc smelting

15 Artisanal zinc smelting in Xinguanzhai area in Guizhou

16 Artisanal zinc smelting in Henizhai area

17 Zinc smelting in Haozidong

18 Zinc smelting furnace 2ZnCO 3 + C 2Zn + 3CO 2

19 2ZnS + 2C + 5O 2 2 ZnCO 3 + 2SO 2 Desulphurization process

20 Table 1 Mercury concentrations in zinc ores, smelting residue, coal and coal ash. Hg concentration (mg kg -1 ) Min Max Average SD n Sulfide ore Oxide ore Desulfurized ore Smelting residue Coal Coal bottom ash

21 Hg emission factors from artisanal zinc smelting average mercury emission factor from Zn smelting using sulfide ores is 155 with a range from 83 to 359 g Hg t -1 of Zn produced; average mercury emission factor of Zn smelting using oxide ores is 79 with a range from 8 to 388 g Hg t -1 of Zn produced

22 Hg emission(t) Year Estimation of annaul Hg emission from Zn smelting (Feng et al., Atmospheric Environment, 2004)

23 Case studies on mercury emissions from industrial sources in China Mercury emission from artisanal mercury smelting Mercury emission from artisanal zinc smelting Mercury emission from large scale zinc smelting

24 Investigated smelters 1.Zhuzhou, Hunan province ( Electrolytic process ) 2.Huludao, Liaoning province (Retort process) 3.Shaoguan, Guangdong province (Imperial Smelting Process (ISP)) 4.Jinding, Yunnan province ( Electrolytic process )

25 Zn Smelter at Zhuzhou Zinc Smelter at Shaoguan Zn smelter at Huludao Zn smelter at Jinding

26 Mass Balance Method Mercury input=mercury output Input:Mercury in zinc ores Output: I Mercury in ashes Ⅱ Mercury in acidic waste water III Mercury in wet dust IV Mercury recovered from flue gas Ⅴ Mercury in sulfuric acid Ⅵ Mercury in flue gas

27 Mercury emission factors from Zn smelters Smelting process Emission factor(g t -1 ) Electrolytic process, with mercury recover Electrolytic process, without mercury recover Retort process 34 Imperial Smelting Process (ISP) 122

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29 Annual Zn production reached tons in Shimian

30 Total gaseous mercury (TGM) concentrations in ambient air at Moxi sampling site, Southwestern China (Fu and Feng et al., 2008)

31 Annual Zn production reached tons in Shimian

32 TGM concentration (ng m -3 ) Spatial distributions of TGM concentrations in Mt. Gongga area th percentile th percentile Mean Median 25th percentile 5th percentile 10 1 C1 C2 C3 T1 V1 V2 V3 V4 R1 R2 R3 R4 R5 R6 Sampling site

33 TGM concentration (ng m -3 ) Short term measurement of TGM concentrations in ambient air in Shimian city (Fu et al., in review) Shi mi an : : : :00 Time

34 Wind frequency distribution and wind directional dependence of TGM concentration at Moxi sampling site Wind frequency (%) TGM concentration (ng m -3 )

35 Table 1. Emission factors for total Hg from industrial sources in China Source category Unit Emission factor 1. Fuel oil for stationary sources g t -1 oil a 2. Gasoline, diesel, and kerosene g t -1 oil a 3. Biofuel combustion g t -1 biofuel b 4. Grassland/savanna burning g t c 5. Waste and residue burning Agricultural residue Household waste g t -1 residue g t -1 waste d 2.80 e 6. Cement production g t -1 cement f 7. Iron and steel production g t -1 steel 0.04 g 8. Caustic soda production g t h 9. Non-ferrous metal smelting Zinc (Zn) Copper (Cu) Lead (Pb) Gold (Au): large-scale production Gold (Au): artisanal production g t -1 Zn g t -1 Cu g t -1 Pb t t -1 Au t t -1 Au i 9.6 j 43.6 j 0.79 j 15.0 k 10. Mercury mining kg t -1 Hg 45.0 k 11. Battery and fluorescent lamp production t t -1 Hg used 0.05 k

36 Speciation of total mercury for each major source type (as fraction of the total) (Pacyna and Pacyna, 2002; Friedli et al. (2001, 2003a, b) ) Source category Hg 0 Hg 2+ Hg p 1. Fuel oil for stationary sources (e.g., power plants, industrial use) a 2. Gasoline, diesel, and kerosene combustion a b Biofuel combustion b Grassland/savanna burning b Waste and residue burning b Cement production a Iron and steel production a Caustic soda production a Non-ferrous metal smelting a Mercury mining c Battery and fluorescent lamp production c

37 Mercury emissions from industrial sources in China in 1999 (tons) Source category Fuel consumption Hg Hg 0 Hg 2+ Hg p or material yield Fuel oil for stationary sources t a Gasoline, diesel, and kerosene t a Biofuel combustion t b Grassland/savanna burning t c Waste and residue burning Agricultural residue t c Household waste t d Cement production t e Iron and steel production t e Caustic soda production t d Non-ferrous metal smelting Zinc (Zn) t f 73 Total (66%) 3.65 Copper (Cu) t f Zn Lead (Pb) t f Gold (Au): large scale 20.4 t d Cu Gold (Au): artisanal 1.9 t g Pb Mercury mining t f Battery/fluorescent lamp production Au 44.6 ( ) t h Total

38 Mercury emission (ton) Mercury emission trends from industrial sources from 1995 to Total a) Hg0 b) Hg2+ c) Hgp Year

39 Mercury emissions (ton) Mercury emission trends from non-ferrous metal smelting sector from 1995 to Nonferrous metals smelting Zn Cu Pb Au: large scale Au: artisanal Year

40 Mercury emissions (ton) Mercury emission trends from Cement production and battery/fluorescent lamp production sectors from 1995 to Battery/fluorescent lamp production Cement production Year

41 Uncertainties Emission factor Activity level

42 95% confidence interval (+/-) Figure 1. Uncertainty (%) in Hg emission estimates by sector (95% confidence intervals, ±, modified from Streets, et al., 2005). 500% 450% 400% 350% 300% 250% 200% 150% 100% 50% 0% Fuel oil for stationary use Gasoline, diesel, kerosene Biofuels Grassland/savanna burning Forest burning Ag residue burning Household waste burning Coal mines spontaneous burning Cement production Iron and steel production Caustic soda production Zinc smelting Copper smelting Lead smelting Gold smelting: large scale Gold smelting: artisanal Mercury mining Battery/lamp production

43 Research recommendation Surveys are needed to evaluate mercury contents in raw materials of different industrial categories. Mercury balance studies are necessarily needed for representative plants of different industrial sources to determine mercury emission factors. The speciation of mercury emissions from different industrial sources are also urgently needed in order to better understand the atmospheric fate of mercury emitted from these sources.