scholarly journals Perfluorocarbons in the global atmosphere: tetrafluoromethane, hexafluoroethane, and octafluoropropane

2010 ◽  
Vol 10 (11) ◽  
pp. 5145-5164 ◽  
Author(s):  
J. Mühle ◽  
A. L. Ganesan ◽  
B. R. Miller ◽  
P. K. Salameh ◽  
C. M. Harth ◽  
...  
Keyword(s):  
Primary Aluminum ◽  
Anthropogenic Sources ◽  
Aluminum Production ◽  
Emission Sources ◽  
Atmospheric Gases ◽  
Atmospheric Measurements ◽  
Top Down ◽  
Metal Production ◽  
D 12 ◽  
Global Emissions

Abstract. We present atmospheric baseline growth rates from the 1970s to the present for the long-lived, strongly infrared-absorbing perfluorocarbons (PFCs) tetrafluoromethane (CF4), hexafluoroethane (C2F6), and octafluoropropane (C3F8) in both hemispheres, measured with improved accuracies (~1–2%) and precisions (<0.3%, or <0.2 ppt (parts per trillion dry air mole fraction), for CF4; <1.5%, or <0.06 ppt, for C2F6; <4.5%, or <0.02 ppt, for C3F8 within the Advanced Global Atmospheric Gases Experiment (AGAGE). Pre-industrial background values of 34.7±0.2 ppt CF4 and 0.1±0.02 ppt C2F6 were measured in air extracted from Greenland ice and Antarctic firn. Anthropogenic sources are thought to be primary aluminum production (CF4, C2F6, C3F8), semiconductor production (C2F6, CF4, C3F8) and refrigeration use (C3F8). Global emissions calculated with the AGAGE 2-D 12-box model are significantly higher than most previous emission estimates. The sum of CF4 and C2F6 emissions estimated from aluminum production and non-metal production are lower than observed global top-down emissions, with gaps of ~6 Gg/yr CF4 in recent years. The significant discrepancies between previous CF4, C2F6, and C3F8 emission estimates and observed global top-down emissions estimated from AGAGE measurements emphasize the need for more accurate, transparent, and complete emission reporting, and for verification with atmospheric measurements to assess the emission sources of these long-lived and potent greenhouse gases, which alter the radiative budget of the atmosphere, essentially permanently, once emitted.

scholarly journals Perfluorocarbons in the global atmosphere: tetrafluoromethane, hexafluoroethane, and octafluoropropane

2010 ◽  
Vol 10 (3) ◽  
pp. 6485-6536 ◽  
Author(s):  
J. Mühle ◽  
A. L. Ganesan ◽  
B. R. Miller ◽  
P. K. Salameh ◽  
C. M. Harth ◽  
...  
Keyword(s):  
Primary Aluminum ◽  
Anthropogenic Sources ◽  
Aluminum Production ◽  
Emission Sources ◽  
Atmospheric Gases ◽  
Atmospheric Measurements ◽  
Top Down ◽  
Metal Production ◽  
D 12 ◽  
Global Emissions

Abstract. We present atmospheric baseline growth rates from the 1970s to the present for the long-lived, strongly infrared-absorbing perfluorocarbons (PFCs) tetrafluoromethane (CF4), hexafluoroethane (C2F6), and octafluoropropane (C3F8) in both hemispheres, measured with improved accuracies (~1–2%) and improved precisions (<0.3%, or <0.2 ppt (parts-per-trillion), for CF4; <1.5%, or <0.06 ppt, for C2F6; <4.5%, or <0.02 ppt, for C3F8) within the Advanced Global Atmospheric Gases Experiment (AGAGE). Pre-industrial background values of 34.7±0.2 ppt CF4 and 0.1±0.02 ppt C2F6 were measured in air extracted from Greenland ice and Antarctic firn. Anthropogenic sources are thought to be primary aluminum production (CF4, C2F6, C3F8), semiconductor production (C2F6, CF4, C3F8) and refrigeration use (C3F8). Global emissions calculated with the AGAGE 2-D 12-box model are significantly higher than most previous emission estimates. The sum of CF4 and C2F6 emissions estimated from aluminum production and non-metal production are lower than observed global top-down emissions, with gaps of ~6.4–7.6 Gg/yr CF4 in recent years. The significant discrepancies between previous CF4, C2F6, and C3F8 emission estimates and observed global top-down emissions estimated from AGAGE measurements emphasize the need for more accurate, transparent, and complete emission reporting, and for verification with atmospheric measurements to assess the emission sources of these long-lived and potent greenhouse gases, which alter the radiative budget of the atmosphere essentially permanently once emitted.

Global budget of trace metal sources

1995 ◽  
Vol 3 (2) ◽  
pp. 145-159 ◽  
Author(s):  
Jozef M. Pacyna ◽  
M. Trevor Scholtz ◽  
Y.-F. (Arthur) Li
Keyword(s):  
Trace Metals ◽  
Large Body ◽  
Global Scale ◽  
Anthropogenic Sources ◽  
Metal Production ◽  
Terrestrial Environment ◽  
Anthropogenic Inputs ◽  
Global Emission ◽  
Global Budgets ◽  
Global Emissions

Global emission inventories, being the key information for the global budgets of trace metals, have become available only recently. The latest information on emissions and sources of trace metals on a global scale is presented in this paper. As the global assessments are prepared on the basis of estimates of regional emissions, these latter data are also reviewed here. A comparison of the worldwide atmospheric emissions from natural and anthropogenic sources suggests that various human activities are the dominant source of many trace metals, including As, Cd, Pb, and Zn. A comparison of the atmospheric and aquatic emissions indicates that, for most of the trace metals, the annual anthropogenic inputs into water exceed the quantities emitted to the atmosphere. However, the largest quantities of trace metals are discharged to the terrestrial environment. So far, the Pb budget seems to be the most accurate owing to a large body of information available on this element. The largest emissions of Pb were estimated for gasoline combustion, contributing about two thirds of the total emissions to the atmosphere. Emissions from nonferrous metal production contributed about one quarter. Emissions from the European and Asian sources contributed each about one third of the global emissions, followed by emissions from sources in North America. A spatial distribution of the global Pb emissions is presented within a 1 × 1° grid system.Key words: trace metals, lead, global emission, emission map.

scholarly journals Unexpected nascent atmospheric emissions of three ozone-depleting hydrochlorofluorocarbons

2021 ◽  
Vol 118 (5) ◽  
pp. e2010914118
Author(s):  
Martin K. Vollmer ◽  
Jens Mühle ◽  
Stephan Henne ◽  
Dickon Young ◽  
Matthew Rigby ◽  
...  
Keyword(s):  
Early Stage ◽  
Stratospheric Ozone ◽  
Montreal Protocol ◽  
Atmospheric Gases ◽  
Chemical Production ◽  
Atmospheric Measurements ◽  
Harmful Emissions ◽  
End Use ◽  
Effective Development ◽  
Global Emissions

Global and regional atmospheric measurements and modeling can play key roles in discovering and quantifying unexpected nascent emissions of environmentally important substances. We focus here on three hydrochlorofluorocarbons (HCFCs) that are restricted by the Montreal Protocol because of their roles in stratospheric ozone depletion. Based on measurements of archived air samples and on in situ measurements at stations of the Advanced Global Atmospheric Gases Experiment (AGAGE) network, we report global abundances, trends, and regional enhancements for HCFC-132b (CH2ClCClF2), which is newly discovered in the atmosphere, and updated results for HCFC-133a (CH2ClCF3) and HCFC-31 (CH2ClF). No purposeful end-use is known for any of these compounds. We find that HCFC-132b appeared in the atmosphere 20 y ago and that its global emissions increased to 1.1 Gg⋅y−1 by 2019. Regional top-down emission estimates for East Asia, based on high-frequency measurements for 2016–2019, account for ∼95% of the global HCFC-132b emissions and for ∼80% of the global HCFC-133a emissions of 2.3 Gg⋅y−1 during this period. Global emissions of HCFC-31 for the same period are 0.71 Gg⋅y−1. Small European emissions of HCFC-132b and HCFC-133a, found in southeastern France, ceased in early 2017 when a fluorocarbon production facility in that area closed. Although unreported emissive end-uses cannot be ruled out, all three compounds are most likely emitted as intermediate by-products in chemical production pathways. Identification of harmful emissions to the atmosphere at an early stage can guide the effective development of global and regional environmental policy.

Evaluation of the reactivity of treated spent pot lining from primary aluminum production as cementitious materials

2021 ◽  
Vol 170 ◽  
pp. 105584
Author(s):  
Victor Brial ◽  
Hang Tran ◽  
Luca Sorelli ◽  
David Conciatori ◽  
Claudiane M. Ouellet-Plamondon
Keyword(s):  
Primary Aluminum ◽  
Cementitious Materials ◽  
Aluminum Production ◽  
Primary Aluminum Production

Seasonal changes in the mineral compositions of tropospheric dust in the industrial region of Upper Silesia, Poland

2003 ◽  
Vol 67 (6) ◽  
pp. 1231-1241 ◽  
Author(s):  
M. Jablonska ◽  
J. Janeczek ◽  
F. J. M. Rietmeijer
Keyword(s):  
Electron Microscopy ◽  
Seasonal Changes ◽  
Anthropogenic Sources ◽  
Emission Sources ◽  
Upper Silesia ◽  
Industrial Dust ◽  
Transmission Electron ◽  
High Emission ◽  
Analytical Scanning Electron Microscopy ◽  
Winter Time

AbstractThe tropospheric dust loading in Upper Silesia (Poland) shows a steady, annually averaged supply of minerals from natural and anthropogenic sources, industrial dust emitters, domestic heating, transportation, but with superimposed seasonal changes for some dust types. Samples of airborne and deposited particles were collected at monthly intervals between 1996 and 2001 in several cities of Upper Silesia. Dust samples were examined by X-ray powder diffraction, analytical transmission electron microscopy, analytical scanning electron microscopy, and electron microprobe microanalysis. The most common dust included quartz, gypsum, coke, soot, hematite, magnetite, wüstite, bassanite, graphite and various K-, Fe- and Mg-bearing aluminosilicates, in order of decreasing abundance. Minor phases included α-iron, sulphur, sphalerite, halite, sylvite, hercynite, franklinite, baryte, dolomite, ankerite, apatite, olivine and feldspars. Quartz, and specific industrial minerals, e.g. spinels, sphalerite, olivine and iron, occurred throughout the year in almost constant abundances. The amounts of all other dust components show seasonal variations; gypsum, baryte and other sulphates are particularly abundant in winter. In general, minerals related to low-emission sources are abundant in the winter time, while both natural dusts and dust from high-emission sources are predominant during the summer.

Deactivation of Red Mud by Primary Aluminum Production Wastes

2021 ◽  
Vol 1040 ◽  
pp. 109-116
Author(s):  
V.Yu. Piirainen ◽  
A.A. Barinkova ◽  
V.N. Starovoytov ◽  
V.M. Barinkov
Keyword(s):  
Carbon Dioxide ◽  
Red Mud ◽  
Negative Impact ◽  
Waste Product ◽  
Primary Aluminum ◽  
Raw Material ◽  
Aluminum Production ◽  
Environmentally Safe ◽  
Primary Aluminum Production ◽  
Knowledge Intensive

Current global environmental challenges and, above all, global warming associated with a change in the carbon balance in the atmosphere has led to the need for urgent and rapid search for ways to reduce greenhouse gas emissions into the atmosphere, which primarily include carbon dioxide as a by-product of human activity and technological progress. One of these ways is the creation of industries with a complete cycle of turnover of carbon dioxide. Aluminum is the most sought-after nonferrous metal in the world, but its production is not environmentally safe, so it constantly requires the development of knowledge-intensive technologies to improve the technological process of cleaning and disposal of production waste, primarily harmful emissions into the atmosphere. Another environmental problem related to aluminum production is the formation and accumulation in mud lagoon of huge amounts of so-called highly alkaline "red mud," which is a waste product of natural bauxite raw material processing into alumina - the feedstock for aluminum production. Commonly known resources and technological methods of neutralizing red mud and working with it as ore materials for further extraction of useful components are still not used because of their low productivity and cost-effectiveness. This article describes the negative impact of waste in the form of "red" mud and carbon dioxide of primary aluminum production on the environment. The results showed that thanks to carbonization of red mud using carbon dioxide, it is possible to achieve rapid curing and its compact formation for safer transportation and storage until further use. Strength tests of concrete samples filled with deactivated red mud were also carried out, which showed the prospects of using concrete with magnesia binder.

scholarly journals Inverse modelling of CF<sub>4</sub> and NF<sub>3</sub> emissions in East Asia

2018 ◽  
Vol 18 (18) ◽  
pp. 13305-13320 ◽  
Author(s):  
Tim Arnold ◽  
Alistair J. Manning ◽  
Jooil Kim ◽  
Shanlan Li ◽  
Helen Webster ◽  
...  
Keyword(s):  
South Korea ◽  
East Asia ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Atmospheric Gases ◽  
Atmospheric Measurements ◽  
Small Uncertainty ◽  
Measurement Location ◽  
Atmospheric Transport Model ◽  
Good Agreement

Abstract. Decadal trends in the atmospheric abundances of carbon tetrafluoride (CF4) and nitrogen trifluoride (NF3) have been well characterised and have provided a time series of global total emissions. Information on locations of emissions contributing to the global total, however, is currently poor. We use a unique set of measurements between 2008 and 2015 from the Gosan station, Jeju Island, South Korea (part of the Advanced Global Atmospheric Gases Experiment network), together with an atmospheric transport model, to make spatially disaggregated emission estimates of these gases in East Asia. Due to the poor availability of good prior information for this study, our emission estimates are largely influenced by the atmospheric measurements. Notably, we are able to highlight emission hotspots of NF3 and CF4 in South Korea due to the measurement location. We calculate emissions of CF4 to be quite constant between the years 2008 and 2015 for both China and South Korea, with 2015 emissions calculated at 4.3±2.7 and 0.36±0.11 Gg yr−1, respectively. Emission estimates of NF3 from South Korea could be made with relatively small uncertainty at 0.6±0.07 Gg yr−1 in 2015, which equates to ∼1.6 % of the country's CO2 emissions. We also apply our method to calculate emissions of CHF3 (HFC-23) between 2008 and 2012, for which our results find good agreement with other studies and which helps support our choice in methodology for CF4 and NF3.

Introduction to Aluminum

2019 ◽  
Author(s):  
Alexey Sverdlin
Keyword(s):  
Ferrous Metal ◽  
Primary Aluminum ◽  
Aluminum Production ◽  
The World ◽  
Annual Consumption

Aluminum is the most heavily consumed non-ferrous metal in the world with an annual consumption of approximately 24 million tons of which it is estimate that 75% of this total amount is primary aluminum (aluminum extracted from ore). This article provides an overview of aluminum ores and their composition, reduction of aluminum, production of commercial quality aluminum, extraction, refinement and the production of ultrapure aluminum.

Carbothermic Reduction Methods for Alumina

2019 ◽  
Author(s):  
Efthymios Balomenos ◽  
Dimitrios Gerogiorgis
Keyword(s):  
Carbothermic Reduction ◽  
Energy Savings ◽  
Greenhouse Gas Emission ◽  
Industrial Process ◽  
Primary Aluminum ◽  
Aluminum Carbide ◽  
Aluminum Production ◽  
Capital Costs ◽  
Reduction Methods ◽  
The 19Th Century

The Hall–Héroult process for the electrolytic reduction of alumina was developed at the end of the 19th century and is still currently the only industrial process for the production of primary aluminum. Today, this process is ranked among the most energy- and CO2intensive industrial processes. Direct carbothermic reduction of alumina has been proposed as an alternative process, which can substantially improve the sustainability of primary aluminum production, leading to energy savings of up to 21% and reduction in greenhouse gas emission of up to 52%, while plant capital costs can be reduced up to 50%. However, processes developed so far suffer from low aluminum yields, primarily due to aluminum carbide and oxycarbide formation and aluminum vaporization phenomena. This article presents a thermodynamic study of the Al–C–O system and a review on the alumina carbothermic processes developed so far.

First year of real-time VOC measurements at the SIRTA facility (Paris region, France): diurnal and seasonal variabilities, impact of lockdowns on air quality

2021 ◽  
Author(s):  
Leïla Simon ◽  
Valérie Gros ◽  
Jean-Eudes Petit ◽  
François Truong ◽  
Roland Sarda-Esteve ◽  
...  
Keyword(s):  
Air Quality ◽  
Atmospheric Chemistry ◽  
Seasonal Variability ◽  
Anthropogenic Sources ◽  
First Year ◽  
Good Representation ◽  
Atmospheric Measurements ◽  
Paris Region ◽  
The Impact

&lt;p&gt;Volatile Organic Compounds (VOCs) have direct influences on air quality and climate. They also play a key role in atmospheric chemistry, as they are precursors of secondary pollutants, such as ozone (O&lt;sub&gt;3&lt;/sub&gt;) and secondary organic aerosols (SOA).&lt;/p&gt;&lt;p&gt;Long-term datasets of in-situ atmospheric measurements are crucial to characterize the variability of atmospheric chemical composition. Online and continuous measurements of O&lt;sub&gt;3&lt;/sub&gt;, NO&lt;sub&gt;x&lt;/sub&gt; and aerosols have been achieved at the SIRTA-ACTRIS facility (Paris region, France), since 2012. Regarding VOCs, they have been measured there for several years thanks to bi-weekly samplings followed by offline Gas Chromatography analysis. However, this method doesn&amp;#8217;t provide a good representation of the temporal variability of VOC concentrations. To tackle this issue, online VOC measurements using a Proton-Transfer-Reaction Quadrupole Mass-Spectrometer (PTR-Q-MS) have been started in January 2020.&lt;/p&gt;&lt;p&gt;The dataset acquired during the first year of online VOC measurements is analyzed, which gives insights on VOC seasonal variability. The additional long-term datasets obtained from co-located measurements (O&lt;sub&gt;3&lt;/sub&gt;, NO&lt;sub&gt;x&lt;/sub&gt;, aerosol physical and chemical properties, meteorological parameters) are also used for the sake of this study.&lt;/p&gt;&lt;p&gt;Due to Covid-19 pandemic, the year 2020 notably comprised a total lockdown in France in Spring, and a lighter one in Autumn. Therefore, a focus can be made on the impact of these lockdowns on the VOC variability and sources. To this end, the diurnal cycles of VOCs considered markers for anthropogenic sources are carefully investigated. Results notably indicate that markers for traffic and wood burning sources behave quite differently during the Spring lockdown in comparison to the other periods. A source apportionment analysis using positive matrix factorization allows to further document the seasonal variability of VOC sources and the impacts on air quality associated with the lockdown measures.&lt;/p&gt;

Sign in / Sign up

Export Citation Format

Share Document