Quantification of stack emissions from marine vessels

Ship emission data from fixed and mobile platforms were obtained during 5 weeks in October and November of 2015. The main objective was to study the "real life" ship emissions of gases and particles in different modes of ship operation in the vicinity of the harbor, from open sea to berth. These emissions can be used to calculate the impact of shipping activities on air quality in the LA basin. Since ships are supposed to run on low sulfur fuel it is interesting how the new low sulfur fuel impacts also emissions of particles, in addition to sulfur. During the project we found several ships running on high sulfur fuel. During the presentation we will describe the method and show example of data from the project

Quantification of stack emissions from marine vessels

Ship emission data from fixed and mobile platforms were obtained during 5 weeks in October and November of 2015. The main objective was to study the "real life" ship emissions of gases and particles in different modes of ship operation in the vicinity of the harbor, from open sea to berth. These emissions can be used to calculate the impact of shipping activities on air quality in the LA basin. Since ships are supposed to run on low sulfur fuel it is interesting how the new low sulfur fuel impacts also emissions of particles, in addition to sulfur. During the project we found several ships running on high sulfur fuel. During the presentation we will describe the method and show example of data from the project

Remote Quantification of Stack Emissions from Marine Vessels

Stationary and mobile (on-vessel) measurements of ship specific emission factors and total emission were carried out in the port of Los Angeles and Long Beach. The measurement techniques developed to characterize individual ship emissions were presented. The data were obtained with a zenith DOAS technique for NO 2 and "in-situ" sniffer technique for SO 2 , NO x , CO 2 , and particulates. The measured particle properties corresponded to particulate number, particulate mass, and black and organic carbon. Total emissions of NO 2 from the harbors were also obtained through mobile optical zenith sky measurements. The potential VOC emissions were investigated when fueling the ships and other VOC sources in the harbor using techniques like the Solar Occultation Flux technique. This is an abstract of a paper presented at the A & WMA\u27s 109th Annual Conference & Exhibition (New Orleans, LA 6/20-23/2016)

Mobile optical measurements of emissions and fenceline concentrations from oil and gas production

The mobile measurement platform and optical methods used in the SQAMD project1 allowed for mapping concentrations and measuring fluxes from a large number of sources and source types, and provided very useful information on the relative contribution of small stationary sources to alkane and BTEX emissions in the SCAB. Sources ranged from single oil wells to large tank farms, refineries, and off shore installations. Note that these sources are not subjected to the same regulatory requirements as larger industrial facilities. Future studies aimed at improving the emission estimates in SCAB should include a larger subset of units from all major source categories, and a better characterization of their spatial and temporal variability

Measurements of fugitive emissions of vocs from stationary sources using the SOF method - Standardization efforts and results from recent studies in California

The Solar Occultation Flux (SOF) method is used to screen and quantify VOC emissions from industrial conglomerates down to sub-areas in individual plants, such as a few tank process area or water treatment areas. The SOF method has been applied in several larger campaigns in both Europe and in the US (Mexico City 2006, Texas 2006/2009/2011/2012; Le Havre 2008, Rotterdam 2008/2010 and Antwerp 2010/2016, California 2013/20T5, Tianjin China 2016) and in more than 100 individual plant surveys over the world. The technique has been validated by comparison to other methods and tracer gas releases and it typically has an uncertainty of 30%, mostly due to uncertainties in the wind field. In the various campaign studies it has been found that the measured emissions obtained with SOF are 3–10 times higher than the reported emission obtained by calculations. The SOF method is Best Available Technology in Europe for quantitative measurements of diffuse emissions from refineries and the chemical sector. The technique is presently being standardized by the European CEN

Nitrous acid formation in a snow-free wintertime polluted rural area

Nitrous acid (HONO) photolysis is an important source of hydroxyl radicals (OH) in the lower atmosphere, in particular in winter when other OH sources are less efficient. The nighttime formation of HONO and its photolysis in the early morning have long been recognized as an important contributor to the OH budget in polluted environments. Over the past few decades it has become clear that the formation of HONO during the day is an even larger contributor to the OH budget and additionally provides a pathway to recycle NOx. Despite the recognition of this unidentified HONO daytime source, the precise chemical mechanism remains elusive. A number of mechanisms have been proposed, including gas-phase, aerosol, and ground surface processes, to explain the elevated levels of daytime HONO. To identify the likely HONO formation mechanisms in a wintertime polluted rural environment we present LP-DOAS observations of HONO, NO2, and O3 on three absorption paths that cover altitude intervals from 2 to 31, 45, and 68 m above ground level (a.g.l.) during the UBWOS 2012 experiment in the Uintah Basin, Utah, USA. Daytime HONO mixing ratios in the 2–31 m height interval were, on average, 78 ppt, which is lower than HONO levels measured in most polluted urban environments with similar NO2 mixing ratios of 1–2 ppb. HONO surface fluxes at 19 m a.g.l., calculated using the HONO gradients from the LP-DOAS and measured eddy diffusivity coefficient, show clear upward fluxes. The hourly average vertical HONO flux during sunny days followed solar irradiance, with a maximum of (4.9 ± 0.2)  ×  1010 molec. cm−2 s−1 at noontime. A photostationary state analysis of the HONO budget shows that the surface flux closes the HONO budget, accounting for 63 ± 32 % of the unidentified HONO daytime source throughout the day and 90 ± 30 % near noontime. This is also supported by 1-D chemistry and transport model calculations that include the measured surface flux, thus clearly identifying chemistry at the ground as the missing daytime HONO source in this environment. Comparison between HONO surface flux, solar radiation, NO2 and HNO3 mixing ratios, and results from 1-D model runs suggest that, under high NOx conditions, HONO formation mechanisms related to solar radiation and NO2 mixing ratios, such as photo-enhanced conversion of NO2 on the ground, are most likely the source of daytime HONO. Under moderate to low NO2 conditions, photolysis of HNO3 on the ground seems to be the main source of HONO