Mercury Transformation and Distribution Across a Polyvinyl Chloride (PVC) Production Line in China

Ren, Wen; Duan, Lei; Zhu, Zhenwu; Du, Wei; An, Zhongyi; Xu, Lizhe; Zhang, Chi; Zhuo, Yuqun; Chen, Changhe

doi:10.1021/es404147c

Cited by 31 publications

(34 citation statements)

References 8 publications

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“…However, knowledge gaps in the emission estimates in China remain for the source categories whose emission factors have not been verified. Hg emissions related to the production, consumption and recycling of Hg in artisanal mercury and gold production, polyvinyl chloride (PVC) production, mercury batteries, mercury sphygmomanometers, and mercury thermometers, are potentially large Hg sources in China but have not been well evaluated Ren et al, 2014;Minschwaner et al, 2010). Other reasons causing earlier underestimation include natural emissions and conversion of GOM and/or PBM to GEM in the stack or in the plume during transit (Jaffe et al, 2005).…”

Section: Inferences On Hg Emissions In Chinamentioning

confidence: 99%

Observations of atmospheric mercury in China: a critical review

et al. 2015

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Abstract. China presently contributes the largest amount of anthropogenic mercury (Hg) emission into the atmosphere in the world. Over the past decade, numerous studies have been conducted to characterize the concentration and forms of atmospheric Hg in China, which provide insights into the spatial and temporal distributions of atmospheric Hg through ground-based measurements at widely diverse geographical locations and during cruise and flight campaigns. In this paper, we present a comprehensive review of the state of understanding in atmospheric Hg in China. Gaseous elemental mercury (GEM) and particulate-bound mercury (PBM) measured at the remote sites in China are substantially elevated compared to the background values in the Northern Hemisphere. In Chinese urban areas, the highly elevated GEM, PBM and gaseous oxidized mercury (GOM) were mainly derived from local anthropogenic Hg emissions, whereas regional anthropogenic emissions and long-range transport from domestic source regions are the primary causes of the elevated GEM and PBM concentrations at remote sites. Using 7-9 years of continuous observations at a remote site and an urban site, a slight increase in atmospheric GEM (2.4-2.5 % yr −1 ) was identified (paired samples test: p < 0.01), which is in agreement with the increasing domestic anthropogenic emissions. Anthropogenic GEM emission quantity in China estimated through the observed GEM / CO concentration ratios ranged from 632 to 1138 t annually over the past decade, 2-3 times larger than published values using emission activity data. Modeling results and filed measurements show dry deposition is the predominant process for removing Hg from the atmosphere, 2.5-9.0 times larger than wet deposition, due to the elevated atmospheric GEM and PBM concentrations that facilitate dry deposition to terrestrial landscapes. Further studies to reconcile the observed and simulated Hg concentrations, to understand the impact of domestic emission reduction on Hg concentration and deposition and to delineate the role of Hg emission and deposition of China in the global Hg biogeochemical cycle, are needed.

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Section: Inferences On Hg Emissions In Chinamentioning

confidence: 99%

Observations of atmospheric mercury in China: a critical review

et al. 2015

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“…Mercury chloride catalyst waste (HgCl 2 ) spontaneously forms through catalyst erosion in the presence of hydrogen chloride and acetylene during PVC manufacturing . It can further transform into different chemical species of mercury . Although PVC is produced from acetylene without direct involvement of calcium carbide, the manufacturing processes are frequently combined to facilitate their optimization .…”

Section: Sustainable Access Usage and Recycling Of Calcium Carbidementioning

confidence: 99%

Calcium‐Based Sustainable Chemical Technologies for Total Carbon Recycling

2019

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Calcium carbide, a stable solid compound composed of two atoms of carbon and one of calcium, has proven its effectiveness in chemical synthesis, due to the safety and convenience of handling the C≡C acetylenic units. The areas of CaC2 application are very diverse, and the development of calcium‐mediated approaches resolves several important challenges. This Review aims to discuss the laboratory chemistry of calcium carbide, and to go beyond its frontiers to organic synthesis, life sciences, materials and construction, carbon dioxide capturing, alloy manufacturing, and agriculture. The recyclability of calcium carbide and the availability of large‐scale industrial production facilities, as well as the future possibility of fossil‐resource‐independent manufacturing, position this compound as a key chemical platform for sustainable development. Easy regeneration and reuse of the carbide highlight calcium‐based sustainable chemical technologies as promising instruments for total carbon recycling.

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“…The production of polyvinyl chloride (PVC) with the calcium carbide process utilizes a catalyst containing large amounts of mercury. Ren et al (2014) conducted on-site measurements in a PVC production line and found that 71.5 % of the total mercury was lost from the catalyst, most of which was recovered by the mercury remover, accounting for 46 % of the total mercury. The total mercury emitted to the atmosphere only accounted for less than 1 % of the total mercury in the catalyst.…”

Section: Mercury Speciation and Transformation In Flue Gas From Pvc Pmentioning

confidence: 99%

Mercury transformation and speciation in flue gases from anthropogenic emission sources: a critical review

et al. 2016

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Abstract. Mercury transformation mechanisms and speciation profiles are reviewed for mercury formed in and released from flue gases of coal-fired boilers, non-ferrous metal smelters, cement plants, iron and steel plants, waste incinerators, biomass burning and so on. Mercury in coal, ores, and other raw materials is released to flue gases in the form of Hg 0 during combustion or smelting in boilers, kilns or furnaces. Decreasing temperature from over 800 • C to below 300 • C in flue gases leaving boilers, kilns or furnaces promotes homogeneous and heterogeneous oxidation of Hg 0 to gaseous divalent mercury (Hg 2+ ), with a portion of Hg 2+ adsorbed onto fly ash to form particulate-bound mercury (Hg p ). Halogen is the primary oxidizer for Hg 0 in flue gases, and active components (e.g., TiO 2 , Fe 2 O 3 , etc.) on fly ash promote heterogeneous oxidation and adsorption processes. In addition to mercury removal, mercury transformation also occurs when passing through air pollution control devices (APCDs), affecting the mercury speciation in flue gases. In coal-fired power plants, selective catalytic reduction (SCR) system promotes mercury oxidation by 34-85 %, electrostatic precipitator (ESP) and fabric filter (FF) remove over 99 % of Hg p , and wet flue gas desulfurization system (WFGD) captures 60-95 % of Hg 2+ . In non-ferrous metal smelters, most Hg 0 is converted to Hg 2+ and removed in acid plants (APs). For cement clinker production, mercury cycling and operational conditions promote heterogeneous mercury oxidation and adsorption. The mercury speciation profiles in flue gases emitted to the atmosphere are determined by transformation mechanisms and mercury removal efficiencies by various APCDs. For all the sectors reviewed in this study, Hg p accounts for less than 5 % in flue gases. In China, mercury emission has a higher Hg 0 fraction (66-82 % of total mercury) in flue gases from coal combustion, in contrast to a greater Hg 2+ fraction (29-90 %) from non-ferrous metal smelting, cement and iron and/or steel production. The higher Hg 2+ fractions shown here than previous estimates may imply stronger local environmental impacts than previously thought, caused by mercury emissions in East Asia. Future research should focus on determining mercury speciation in flue gases from iron and steel plants, waste incineration and biomass burning, and on elucidating the mechanisms of mercury oxidation and adsorption in flue gases.

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Mercury Transformation and Distribution Across a Polyvinyl Chloride (PVC) Production Line in China

Cited by 31 publications

References 8 publications

Observations of atmospheric mercury in China: a critical review

Observations of atmospheric mercury in China: a critical review

Calcium‐Based Sustainable Chemical Technologies for Total Carbon Recycling

Mercury transformation and speciation in flue gases from anthropogenic emission sources: a critical review

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