HR: 1330h
AN: A52C-0819    [PDF]
TI: Use of Sulphur and Boron Isotopes to Identify Natural Gas Processing Emissions Sources
AU: * Bradley, C E
EM: c.erin@shaw.ca
AF: Department of Engineering, University of Calgary 2500 University Dr. NW, Calgary, AB T2N 1N4 Canada
AU: Norman, A
EM: annlisen@phas.ucalgary.ca
AF: Department of Physics & Astronomy, University of Calgary 2500 University Dr. NW, Calgary, AB T2N 1N4 Canada
AU: Wieser, M E
EM: mwieser@ucalgary.ca
AF: Department of Physics & Astronomy, University of Calgary 2500 University Dr. NW, Calgary, AB T2N 1N4 Canada
AB: Natural gas processing results in the emission of large amounts of gaseous pollutants as a result of planned and / or emergency flaring, sulphur incineration, and in the course of normal operation. Since many gas plants often contribute to the same air shed, it is not possible to conclusively determine the sources, amounts, and characteristics of pollution from a particular processing facility using traditional methods. However, sulphur isotopes have proven useful in the apportionment of sources of atmospheric sulphate (Norman et al., 1999), and boron isotopes have been shown to be of use in tracing coal contamination through groundwater (Davidson and Bassett, 1993). In this study, both sulphur and boron isotopes have been measured at source, receptor, and control sites, and, if emissions prove to be sufficiently distinct isotopically, they will be used to identify and apportion emissions downwind. Sulphur is present in natural gas as hydrogen sulphide (H$_{2}$S), which is combusted to sulphur dioxide (SO$_{2}$) prior to its release to the atmosphere, while boron is present both in hydrocarbon deposits as well as in any water used in the process. Little is known about the isotopic abundance variations of boron in hydrocarbon reservoirs, but Krouse (1991) has shown that the sulphur isotope composition of H$_{2}$S in reservoirs varies according to both the concentration and the method of formation of H$_{2}$S. As a result, gas plants processing gas from different reservoirs are expected to produce emissions with unique isotopic compositions. Samples were collected using a high-volume air sampler placed directly downwind of several gas plants, as well as at a receptor site and a control site. Aerosol sulphate and boron were collected on quartz fibre filters, while SO$_{2}$ was collected on potassium hydroxide-impregnated cellulose filters. Solid sulphur samples were taken from those plants that process sulphur in order to compare the isotopic composition with atmospheric measurements. A method was developed to extract and concentrate boron for isotope analysis. Isotopic composition and concentrations of both sulphur and boron were measured in order to determine whether emissions have distinct sulphur and/or boron isotopic compositions. Preliminary results of SO$_{2}$ and solid sulphur analysis show values that range from +3 to +30 \permil.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0345 Pollution--urban and regional (0305)
DE: 0394 Instruments and techniques
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting