Volatile Organic Compounds in Headspace over Electrical Components at 75 to 200°C – Part 1. Identification of Constituents and Emission Rates

2012 ◽  
Vol 9 (2) ◽  
pp. 89-98
Author(s):  
N. D. Paz ◽  
J. E. Rodriguez ◽  
G. A. Eiceman
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Emission Rates ◽  
Volatile Organic ◽  
Electrical Components

scholarly journals Fluxes and concentrations of volatile organic compounds from a South-East Asian tropical rainforest

2010 ◽  
Vol 10 (17) ◽  
pp. 8391-8412 ◽  
Author(s):  
B. Langford ◽  
P. K. Misztal ◽  
E. Nemitz ◽  
B. Davison ◽  
C. Helfter ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Tropical Forests ◽  
Atmospheric Chemistry ◽  
Carbon Flux ◽  
Tropical Rainforest ◽  
East Asian ◽  
Emission Rates ◽  
Reactive Carbon ◽  
Volatile Organic

Abstract. As part of the OP3 field study of rainforest atmospheric chemistry, above-canopy fluxes of isoprene, monoterpenes and oxygenated volatile organic compounds were made by virtual disjunct eddy covariance from a South-East Asian tropical rainforest in Malaysia. Approximately 500 hours of flux data were collected over 48 days in April–May and June–July 2008. Isoprene was the dominant non-methane hydrocarbon emitted from the forest, accounting for 80% (as carbon) of the measured emission of reactive carbon fluxes. Total monoterpene emissions accounted for 18% of the measured reactive carbon flux. There was no evidence for nocturnal monoterpene emissions and during the day their flux rate was dependent on both light and temperature. The oxygenated compounds, including methanol, acetone and acetaldehyde, contributed less than 2% of the total measured reactive carbon flux. The sum of the VOC fluxes measured represents a 0.4% loss of daytime assimilated carbon by the canopy, but atmospheric chemistry box modelling suggests that most (90%) of this reactive carbon is returned back to the canopy by wet and dry deposition following chemical transformation. The emission rates of isoprene and monoterpenes, normalised to 30 °C and 1000 μmol m−2 s−1 PAR, were 1.6 mg m−2 h−1 and 0.46mg m−2 h−1 respectively, which was 4 and 1.8 times lower respectively than the default value for tropical forests in the widely-used MEGAN model of biogenic VOC emissions. This highlights the need for more direct canopy-scale flux measurements of VOCs from the world's tropical forests.

Selected problems concerning volatile organic compounds emission reduction from thick-veneer pine plywood

2020 ◽  
Vol 111 ◽  
pp. 131-20
Author(s):  
Martyna Dyrwal ◽  
Piotr Borysiuk
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Carbonyl Compounds ◽  
Emission Reduction ◽  
Caproic Acid ◽  
Emission Rates ◽  
Wood Material ◽  
Soaking Time ◽  
Volatile Organic ◽  
Higher Temperature

Selected problems concerning volatile organic compounds emission reduction from thick-veneer pine plywood. The paper presents results of research conducted on volatile organic compounds emissions, considering two different production parameter sets for thick-veneer pine plywood, manufactured in industrial conditions. Both types of plywood were produced from raw wood material, which was hydrothermally treated under two different variants of parameters (I – 47˚C, 19 h; II – 55˚C, 24 h). Based on the results it was stated that severe hydrothermal treatment of raw wood material (longer soaking time, higher temperature) had impact on reduction of plywood VOC emission rates. Main VOCs emitted from pine plywood were monoterpenes and carbonyl compounds. Of the monoterpenes, α-pinene and 3-carene had the highest emission. Of the carbonyl group of compounds, the highest emission had hexanal and caproic acid.

First Comprehensive Measurements of Emission Rates of Greenhouse Gases, Volatile Organic Compounds and Reduced Sulfur Compounds from a Tailings Pond in the Alberta Oil Sands

2020 ◽  
Author(s):  
Ralf Staebler ◽  
Samar Moussa ◽  
Yuan You ◽  
Hayley Hung ◽  
Maryam Moradi ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Oil Sands ◽  
Regulatory Compliance ◽  
Sulfur Compounds ◽  
Emission Rates ◽  
Reduced Sulfur Compounds ◽  
Volatile Organic ◽  
Reduced Sulfur

<p>Canada’s Oil Sands Region in northern Alberta contains the world’s largest deposits of commercially exploited bitumen. Extraction of synthetic crude oil from these deposits is a water intensive process, requiring large ponds for water recycling and/or final storage of tailings, already covering a total of over 100 km<sup>2</sup> of liquid surface area in the Athabasca Oil sands. The primary extraction tailings ponds primarily contain sand, silt, clay and unrecovered bitumen, while a few secondary extraction ponds also receive solvents and inorganic and organic by-products of the extraction process. Fugitive emissions of pollutants from these ponds to the atmosphere may therefore be a concern, but until recently, data on emission rates for many pollutants, other than a few reported under regulatory compliance monitoring, were sparse. We present here the results from a comprehensive field campaign to quantify the emissions from a secondary extraction pond to the atmosphere of 68 volatile organic compounds (VOCs), 22 polycyclic aromatic compounds (PACs), 8 reduced sulfur compounds as well as methane, carbon dioxide and ammonia. Three micrometeorological flux methods (eddy covariance, vertical gradients and inverse dispersion modeling) were evaluated for methane fluxes to ensure their mutual comparability. Methane and carbon dioxide fluxes were similar to previous results based on flux chamber measurements. Emission rates for 12 PACs, alkanes and aromatic VOCs, several sulfur species, and ammonia were found to be significant. PACs were dominated by methyl naphthalenes and phenanthrenes, while diethylsulfide and  and n-heptane were the dominant reduced sulfur and VOC species, respectively. The role of these previously unavailable emission rates in regional pollutant budgets will be discussed.</p>

scholarly journals From emissions to ambient mixing ratios: on-line seasonal field measurements of volatile organic compounds over a Norway spruce dominated forest in central Germany

2013 ◽  
Vol 13 (11) ◽  
pp. 30187-30232 ◽  
Author(s):  
E. Bourtsoukidis ◽  
J. Williams ◽  
J. Kesselmeier ◽  
S. Jacobi ◽  
B. Bonn
Keyword(s):  
Volatile Organic Compounds ◽  
Norway Spruce ◽  
Organic Compounds ◽  
Atmospheric Chemistry ◽  
Temperature Dependency ◽  
Emission Rates ◽  
Temperature Dependent ◽  
Central Germany ◽  
Mixing Ratios ◽  
Volatile Organic

Abstract. Biogenic volatile organic compounds (BVOC) are substantial contributors to atmospheric chemistry and physics and demonstrate the close relationship between biosphere and atmosphere. Their emission rates are highly sensitive to meteorological and environmental changes with concomitant impacts on atmospheric chemistry. We have investigated seasonal isoprenoid and oxygenated VOC (oxVOC) fluxes from a Norway spruce (Picea abies) tree in Central Germany and explored the emission responses under various atmospheric conditions. Emission rates were quantified by using dynamic branch enclosure and Proton Transfer Reaction–Mass Spectrometry (PTR-MS) techniques. Additionally, ambient mixing ratios were derived through application of a new box model treatment on the dynamic chamber measurements. These are compared in terms of abundance and origin with the corresponding emissions. Isoprenoids govern the BVOC emissions from Norway spruce, with monoterpenes and sesquiterpenes accounting for 50.8 ± 7.2% and 19.8 ± 8.1% respectively of the total emissions. Normalizing the VOC emission rates, we have observed a trend of reduction of carbon containing emissions from April to November, with an enhancement of oxVOC. Highest emission rates were observed in June for all measured species, with the exception of sesquiterpenes that were emitted most strongly in April. We exploit the wide range of conditions experienced at the site to filter the dataset with a combination of temperature, ozone and absolute humidity values in order to derive the emission potential and temperature dependency development for the major chemical species investigated. A profound reduction of monoterpene emission potential (E30) and temperature dependency (β) was found under low temperature regimes, combined with low ozone levels (E30MT, LTLO3=56 ± 9.1 ng g(dw)−1 h−1, βMT,LTLO3=0.03±0.01 K−1) while a combination of both stresses was found to alter their emissions responses with respect to temperature substantially (E30MT,HTHO3=1420.1 ± 191.4 ng g(dw)−1 h−1, βMT,HTHO3=0.15 ± 0.02 K−1). Moreover, we have explored compound relationships under different atmospheric condition sets, addressing possible co-occurrence of emissions under specific conditions. Finally, we evaluate the temperature dependent algorithm that seems to describe the temperature dependent emissions. Highest emission deviations were observed for monoterpenes and these emission fluctuations were attributed to a fraction which is triggered by an additional light dependency.

scholarly journals Surface–atmosphere fluxes of volatile organic compounds in Beijing

2020 ◽  
Vol 20 (23) ◽  
pp. 15101-15125
Author(s):  
W. Joe F. Acton ◽  
Zhonghui Huang ◽  
Brian Davison ◽  
Will S. Drysdale ◽  
Pingqing Fu ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Emission Inventory ◽  
Central Area ◽  
High Reactivity ◽  
Emission Rates ◽  
Voc Emissions ◽  
Formation Potential ◽  
Surface Atmosphere ◽  
Volatile Organic

Abstract. Mixing ratios of volatile organic compounds (VOCs) were recorded in two field campaigns in central Beijing as part of the Air Pollution and Human Health in a Chinese Megacity (APHH) project. These data were used to calculate, for the first time in Beijing, the surface–atmosphere fluxes of VOCs using eddy covariance, giving a top-down estimation of VOC emissions from a central area of the city. The results were then used to evaluate the accuracy of the Multi-resolution Emission Inventory for China (MEIC). The APHH winter and summer campaigns took place in November and December 2016 and May and June 2017, respectively. The largest VOC fluxes observed were of small oxygenated compounds such as methanol, ethanol + formic acid and acetaldehyde, with average emission rates of 8.31 ± 8.5, 3.97 ± 3.9 and 1.83 ± 2.0 nmol m−2 s−1, respectively, in the summer. A large flux of isoprene was observed in the summer, with an average emission rate of 5.31 ± 7.7 nmol m−2 s−1. While oxygenated VOCs made up 60 % of the molar VOC flux measured, when fluxes were scaled by ozone formation potential and peroxyacyl nitrate (PAN) formation potential the high reactivity of isoprene and monoterpenes meant that these species represented 30 % and 28 % of the flux contribution to ozone and PAN formation potential, respectively. Comparison of measured fluxes with the emission inventory showed that the inventory failed to capture the magnitude of VOC emissions at the local scale.

scholarly journals Emissions of isoprenoids and oxygenated biogenic volatile organic compounds from a New England mixed forest

2010 ◽  
Vol 10 (11) ◽  
pp. 28565-28633
Author(s):  
K. A. McKinney ◽  
B. H. Lee ◽  
A. Vasta ◽  
T. V. Pho ◽  
J. W. Munger
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Forest Canopy ◽  
Emission Rate ◽  
Mixed Forest ◽  
Emission Rates ◽  
Biogenic Volatile Organic Compounds ◽  
Methanol Production ◽  
Short Period ◽  
Volatile Organic

Abstract. Fluxes of biogenic volatile organic compounds, including isoprene, monoterpenes, and oxygenated VOCs measured above a mixed forest canopy in western Massachusetts during the 2005 and 2007 growing seasons are reported. Measurements were made using proton transfer reaction mass spectrometry (PTR-MS) and converted to fluxes using the disjunct eddy covariance technique. Isoprene was by far the predominant BVOC emitted at this site, with summer mid-day average fluxes of 5.3 and 4.4 mg m−2 h−1 in 2005 and 2007, respectively. In comparison, mid-day average fluxes of monoterpenes were 0.21 and 0.15 mg m−2 h−1 in each of these years. On short times scales (days), the diel pattern in emission rate compared well with a standard emission algorithm for isoprene. The general shape of the seasonal cycle and the observed decrease in isoprene emission rate in early September was, however, not well captured by the model. Monoterpene emission rates exhibited dependence on light as well as temperature, as determined from the improved fit to the observations obtained by including a light-dependent term in the model. The mid-day average flux of methanol from the canopy was 0.14 mg m−2 h−1 in 2005 and 0.19 mg m−2 h−1 in 2007, but the maximum flux was observed in spring (29 May 2007), when the flux reached 1.0 mg m−2 h−1. This observation is consistent with enhanced methanol production during leaf expansion. Summer mid-day fluxes of acetone were 0.15 mg m−2 h−1 during a short period in 2005, but only 0.03 mg m−2 h−1 averaged over 2007. Episodes of negative fluxes of oxygenated VOCs, particularly acetone, were observed periodically, especially in 2007. Thus, deposition within the canopy could help explain the low season-averaged flux of acetone in 2007. Fluxes of species of biogenic origin at mass-to-charge (m/z) ratios of 73 (0.05 mg m−2 h−1 in 2005; 0.03 mg m−2 h−1 in 2007) and 153 (5 μg m−2 h−1 in 2007), possibly corresponding to methyl ethyl ketone and an oxygenated terpene, respectively, were also observed.

Sign in / Sign up

Export Citation Format

Share Document