scholarly journals Online measurements of the emissions of intermediate-volatility and semi-volatile organic compounds from aircraft

2013 ◽  
Vol 13 (15) ◽  
pp. 7845-7858 ◽  
Author(s):  
E. S. Cross ◽  
J. F. Hunter ◽  
A. J. Carrasquillo ◽  
J. P. Franklin ◽  
S. C. Herndon ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Volatile Organic Compounds ◽  
Gas Phase ◽  
Organic Compounds ◽  
Operating Conditions ◽  
Organic Vapors ◽  
Pyrolysis Products ◽  
Volatile Organic ◽  
Online Measurements ◽  
Unburned Fuel

Abstract. A detailed understanding of the climate and air quality impacts of aviation requires measurements of the emissions of intermediate-volatility and semi-volatile organic compounds (I/SVOCs) from aircraft. Currently both the amount and chemical composition of aircraft I/SVOC emissions remain poorly characterized. Here we characterize I/SVOC emissions from aircraft, using a novel instrument for the online, quantitative measurement of the mass loading and composition of low-volatility organic vapors. Emissions from the NASA DC8 aircraft were sampled on the ground 143 m downwind of the engines and characterized as a function of engine power from idle (4% maximum rated thrust) through 85% power. Results show that I/SVOC emissions are highest during engine idle operating conditions, with decreasing but non-zero I/SVOC emissions at higher engine powers. Comparison of I/SVOC emissions with total hydrocarbon (THC) measurements, VOC measurements, and an established emissions profile indicates that I/SVOCs comprise 10–20% of the total organic gas-phase emissions at idle, and an increasing fraction of the total gas-phase organic emissions at higher powers. Positive matrix factorization of online mass spectra is used to identify three distinct types of I/SVOC emissions: aliphatic, aromatic and oxygenated. The volatility and chemical composition of the emissions suggest that unburned fuel is the dominant source of I/SVOCs at idle, while pyrolysis products make up an increasing fraction of the I/SVOCs at higher powers. Oxygenated I/SVOC emissions were detected at lower engine powers (≤30%) and may be linked to cracked, partially oxidized or unburned fuel components.

scholarly journals Online measurements of the emissions of intermediate-volatility and semi-volatile organic compounds from aircraft

2013 ◽  
Vol 13 (3) ◽  
pp. 8065-8100
Author(s):  
E. S. Cross ◽  
J. F. Hunter ◽  
A. J. Carrasquillo ◽  
J. P. Franklin ◽  
S. C. Herndon ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Volatile Organic Compounds ◽  
Gas Phase ◽  
Organic Compounds ◽  
Operating Conditions ◽  
Organic Vapors ◽  
Pyrolysis Products ◽  
Volatile Organic ◽  
Online Measurements ◽  
Unburned Fuel

Abstract. A detailed understanding of the climate and air quality impacts of aviation requires detailed measurements of the emissions of intermediate-volatility and semi-volatile organic compounds (I/SVOCs) from aircraft. Currently both the amount and chemical composition of aircraft I/SVOC emissions remain poorly characterized. Here we characterize I/SVOC emissions from aircraft, using a novel instrument for the online, quantitative measurement of the mass loading and composition of low-volatility organic vapors. Emissions from the NASA DC8 aircraft were sampled on the ground, 143 m downwind of the engines and characterized as a function of engine power from ground idle (~4% maximum rated thrust) through 85% power. Results show that I/SVOC emissions are highest during engine-idle operating conditions, with decreasing but non-zero I/SVOC emissions at higher engine powers. Comparison of I/SVOC emissions with total hydrocarbon (THC) measurements, VOC measurements, and an established emissions profile indicates that I/SVOCs comprise 10–20% of the total organic gas phase emissions at idle, and an increasing fraction of the total gas phase organic emissions at higher powers. Positive matrix factorization of online mass spectra is used to identify three distinct types of I/SVOC emissions: aliphatic, aromatic and oxygenated. The volatility and chemical composition of the emissions suggest that unburned fuel is the dominant source of I/SVOCs at idle, while pyrolysis products make up an increasing fraction of the I/SVOCs at higher powers. Oxygenated I/SVOC emissions were detected at lower engine powers (≤30%) and may be linked to cracked, partially oxidized or unburned fuel components.

scholarly journals Considering the future of anthropogenic gas-phase organic compound emissions and the increasing influence of non-combustion sources on urban air quality

2018 ◽  
Vol 18 (8) ◽  
pp. 5391-5413 ◽  
Author(s):  
Peeyush Khare ◽  
Drew R. Gentner
Keyword(s):  
Air Quality ◽  
Chemical Composition ◽  
Volatile Organic Compounds ◽  
Gas Phase ◽  
Organic Compounds ◽  
Motor Vehicles ◽  
Ozone Formation ◽  
Life Cycle Approach ◽  
Volatile Organic ◽  
Emissions Inventories

Abstract. Decades of policy in developed regions has successfully reduced total anthropogenic emissions of gas-phase organic compounds, especially volatile organic compounds (VOCs), with an intentional, sustained focus on motor vehicles and other combustion-related sources. We examine potential secondary organic aerosol (SOA) and ozone formation in our case study megacity (Los Angeles) and demonstrate that non-combustion-related sources now contribute a major fraction of SOA and ozone precursors. Thus, they warrant greater attention beyond indoor environments to resolve large uncertainties in their emissions, oxidation chemistry, and outdoor air quality impacts in cities worldwide. We constrain the magnitude and chemical composition of emissions via several bottom-up approaches using chemical analyses of products, emissions inventory assessments, theoretical calculations of emission timescales, and a survey of consumer product material safety datasheets. We demonstrate that the chemical composition of emissions from consumer products as well as commercial and industrial products, processes, and materials is diverse across and within source subcategories. This leads to wide ranges of SOA and ozone formation potentials that rival other prominent sources, such as motor vehicles. With emission timescales from minutes to years, emission rates and source profiles need to be included, updated, and/or validated in emissions inventories with expected regional and national variability. In particular, intermediate-volatility and semi-volatile organic compounds (IVOCs and SVOCs) are key precursors to SOA, but are excluded or poorly represented in emissions inventories and exempt from emissions targets. We present an expanded framework for classifying VOC, IVOC, and SVOC emissions from this diverse array of sources that emphasizes a life cycle approach over longer timescales and three emission pathways that extend beyond the short-term evaporation of VOCs: (1) solvent evaporation, (2) solute off-gassing, and (3) volatilization of degradation by-products. Furthermore, we find that ambient SOA formed from these non-combustion-related emissions could be misattributed to fossil fuel combustion due to the isotopic signature of their petroleum-based feedstocks.

The rate of photocatalytic oxidation of aromatic volatile organic compounds in the gas-phase

2008 ◽  
Vol 42 (34) ◽  
pp. 7844-7850 ◽  
Author(s):  
Aikaterini K. Boulamanti ◽  
Christos A. Korologos ◽  
Constantine J. Philippopoulos
Keyword(s):  
Volatile Organic Compounds ◽  
Gas Phase ◽  
Organic Compounds ◽  
Photocatalytic Oxidation ◽  
Volatile Organic

Development and validation of a cryogen-free automatic gas chromatograph system (GC-MS/FID) for online measurements of volatile organic compounds

2014 ◽  
Vol 6 (23) ◽  
pp. 9424-9434 ◽  
Author(s):  
Ming Wang ◽  
Limin Zeng ◽  
Sihua Lu ◽  
Min Shao ◽  
Xinglong Liu ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Gas Chromatograph ◽  
Volatile Organic ◽  
Online Measurements ◽  
Development And Validation

A cryogen-free, automatic gas chromatograph system was developed for online measurements of volatile organic compounds in the atmosphere.

Optimisation of secondary electrospray ionisation (SESI) for the trace determination of gas-phase volatile organic compounds

The Analyst ◽  
2010 ◽  
Vol 135 (2) ◽  
pp. 306 ◽  
Author(s):  
Leonard A. Dillon ◽  
Victoria N. Stone ◽  
Laura A. Croasdell ◽  
Peter R. Fielden ◽  
Nicholas J. Goddard ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Gas Phase ◽  
Organic Compounds ◽  
Trace Determination ◽  
Electrospray Ionisation ◽  
Volatile Organic

scholarly journals Aerosol mass yields of selected biogenic volatile organic compounds – a theoretical study with nearly explicit gas-phase chemistry

2019 ◽  
Vol 19 (22) ◽  
pp. 13741-13758
Author(s):  
Carlton Xavier ◽  
Anton Rusanen ◽  
Putian Zhou ◽  
Chen Dean ◽  
Lukas Pichelstorfer ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Gas Phase ◽  
Organic Compounds ◽  
Chemical Mechanism ◽  
Biogenic Volatile Organic Compounds ◽  
Gas Phase Chemistry ◽  
Mass Load ◽  
Volatile Organic ◽  
Phase Chemistry ◽  
Good Agreement

Abstract. In this study we modeled secondary organic aerosol (SOA) mass loadings from the oxidation (by O3, OH and NO3) of five representative biogenic volatile organic compounds (BVOCs): isoprene, endocyclic bond-containing monoterpenes (α-pinene and limonene), exocyclic double-bond compound (β-pinene) and a sesquiterpene (β-caryophyllene). The simulations were designed to replicate an idealized smog chamber and oxidative flow reactors (OFRs). The Master Chemical Mechanism (MCM) together with the peroxy radical autoxidation mechanism (PRAM) were used to simulate the gas-phase chemistry. The aim of this study was to compare the potency of MCM and MCM + PRAM in predicting SOA formation. SOA yields were in good agreement with experimental values for chamber simulations when MCM + PRAM was applied, while a stand-alone MCM underpredicted the SOA yields. Compared to experimental yields, the OFR simulations using MCM + PRAM yields were in good agreement for BVOCs oxidized by both O3 and OH. On the other hand, a stand-alone MCM underpredicted the SOA mass yields. SOA yields increased with decreasing temperatures and NO concentrations and vice versa. This highlights the limitations posed when using fixed SOA yields in a majority of global and regional models. Few compounds that play a crucial role (>95 % of mass load) in contributing to SOA mass increase (using MCM + PRAM) are identified. The results further emphasized that incorporating PRAM in conjunction with MCM does improve SOA mass yield estimation.

scholarly journals Importance of biogenic volatile organic compounds to acyl peroxy nitrates (APN) production in the southeastern US during SOAS 2013

2019 ◽  
Vol 19 (3) ◽  
pp. 1867-1880 ◽  
Author(s):  
Shino Toma ◽  
Steve Bertman ◽  
Christopher Groff ◽  
Fulizi Xiong ◽  
Paul B. Shepson ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Gas Phase ◽  
Organic Compounds ◽  
Model Simulation ◽  
Statistical Correlation ◽  
Organic Nitrates ◽  
Biogenic Volatile Organic Compounds ◽  
The North ◽  
Southeastern Us ◽  
Volatile Organic

Abstract. Gas-phase atmospheric concentrations of peroxyacetyl nitrate (PAN), peroxypropionyl nitrate (PPN), and peroxymethacryloyl nitrate (MPAN) were measured on the ground using a gas chromatograph electron capture detector (GC-ECD) during the Southern Oxidants and Aerosols Study (SOAS) 2013 campaign (1 June to 15 July 2013) in Centreville, Alabama, in order to study biosphere–atmosphere interactions. Average levels of PAN, PPN, and MPAN were 169, 5, and 9 pptv, respectively, and the sum accounts for an average of 16 % of NOy during the daytime (10:00 to 16:00 local time). Higher concentrations were seen on average in air that came to the site from the urban NOx sources to the north. PAN levels were the lowest observed in ground measurements over the past two decades in the southeastern US. A multiple regression analysis indicates that biogenic volatile organic compounds (VOCs) account for 66 % of PAN formation during this study. Comparison of this value with a 0-D model simulation of peroxyacetyl radical production indicates that at least 50 % of PAN formation is due to isoprene oxidation. MPAN has a statistical correlation with isoprene hydroxynitrates (IN). Organic aerosol mass increases with gas-phase MPAN and IN concentrations, but the mass of organic nitrates in particles is largely unrelated to MPAN.

Chemical composition and production of ethanol and other volatile organic compounds in sugarcane silage treated with chemical and microbial additives

2019 ◽  
Vol 59 (4) ◽  
pp. 721
Author(s):  
Lucas Ladeira Cardoso ◽  
Karina Guimarães Ribeiro ◽  
Marcos Inácio Marcondes ◽  
Odilon Gomes Pereira ◽  
Kirsten Weiß
Keyword(s):  
Chemical Composition ◽  
Volatile Organic Compounds ◽  
Lactobacillus Plantarum ◽  
Organic Compounds ◽  
Dry Matter ◽  
Production Systems ◽  
Propionibacterium Acidipropionici ◽  
Pediococcus Pentosaceus ◽  
Ester Formation ◽  
Volatile Organic

Sugarcane silage can be used in animal production systems; however, it is important to apply additives to improve its chemical composition and fermentative quality. We evaluated the effect of chemical (urea and calcium oxide (CaO)) and microbial (Lactobacillus buchneri (LB), Lactobacillus plantarum, Pediococcus pentosaceus, and Propionibacterium acidipropionici) additives on chemical composition, fermentation profile, microorganism population, and production of ethanol and other volatile organic compounds in sugarcane silage. Treatments studied were silage without inoculant (SS), SS with LB, SS with Lactobacillus plantarum and Pediococcus pentosaceus, SS with Lactobacillus plantarum and Propionibacterium acidipropionici, SS with 5 g CaO/kg fresh material (FM) (5CaO), SS with 10 g CaO/kg FM (10CaO), SS with 5 g urea/kg FM (5urea), and SS with 10 g urea/kg FM (10urea). The highest crude protein content (P = 0.001) and the lowest N-linked to fibre content (P = 0.001) occurred when applying urea. None of the treatments reduced the presence of yeast (P = 0.054), but a trend was detected of treatments based on CaO as promising in this Control. The silages treated with CaO had lower ethyl ester and ethanol (average for CaO-based treatments of 0.012 g/kg dry matter and 0.695 g/kg dry matter, respectively), and silages treated with 10urea had less acetone (P = 0.001) and methanol (P = 0.001). The sugarcane silages treated with chemical additive CaO reduced ethanol production and ester formation. There was a high correlation (r = 0.984) between ethyl acetate + ethyl lactate and ethanol contents.

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