Browsing by Subject "emission factor"
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Item Development of an ammonia emission protocol and preliminary emission factor for a central Texas dairy(Texas A&M University, 2004-09-30) Rose, Adam JosephA protocol was developed to measure ammonia emission concentrations from dairies using an isolation flux chamber. A hybrid dairy in Comanche county, Texas, was measured for one week each during August 2002 and January 2003. Sixty total ammonia samples were taken from the free stall barn, open lot, mixing tank, separated solids, compost, and two lagoons using the developed protocol. The ammonia concentration measurements were made using a chemiluminescence analyzer located inside a mobile laboratory. From the emission concentrations recorded, it was estimated that 9.68 metric tons of ammonia were produced from this dairy per year. An emission factor of 13.34 ? 28.80 kilograms per day per thousand head of cattle (kg/day/1000 head) was estimated for this dairy (?95% confidence intervals) during summer conditions. For winter conditions the emission factor was 12.05 ? 12.89 kg/day/1000 head. The 11% difference of the emission factors from summer to winter conditions was predominantly from the change in ambient and control volume temperatures (a mean difference of approximately 25 degrees Celsius), differences in source temperatures, and seasonal variability in husbandry. The adsorption of ammonia onto different polymer tubing used in pollutant stream conveyance was researched for possible systematic losses. Teflon and low density polyethylene (LDPE) were tested for ammonia losses with treatments of: temperature, length, and inlet concentration. Inlet concentration and temperature were significant factors used to describe ammonia adsorption for Teflon, whereas LDPE was also affected by tubing length. These factors were used to create a model to correct the summer dairy measurements for ammonia losses, resulting in an emission factor increase of 8.3% over the original value obtained from the flux chamber. A nitrogen mass balance was performed to estimate the amount of nitrogen available for ammonia formation as excreted - 177.5 kilograms per year per animal (wet basis). The amount of ammonia excreted per year was also estimated to be 26.63 kilograms per year. The measured ammonia emitted from the dairy was five times less than the ammonia excreted and thirty-six times less than the total nitrogen excreted.Item Errors associated with particulate matter measurements on rural sources: appropriate basis for regulating cotton gins(Texas A&M University, 2004-09-30) Buser, Michael DeanAgricultural operations across the United States are encountering difficulties complying with current air pollution regulations for particulate matter (PM). PM is currently regulated in terms of particle diameters less than or equal to a nominal 10 ?m (PM10); however, current legislation is underway to regulate PM with diameters less than or equal to a nominal 2.5 ?m (PM2.5). The goals of this research were to determine the biases and uncertainties associated with current PM10 and PM2.5 sampling methods and to determine the extent to which these errors may impact the determination of cotton gin emission factors. Ideally, PM samplers would produce an accurate measure of the pollutant indicator; for instance, a PM10 sampler would produce an accurate measure of PM less than or equal to 10 ?m. However, samplers are not perfect and errors are introduced because of the established tolerances associated with sampler performance characteristics and the interaction of particle size and sampler performance characteristics. Results of this research indicated that a source emitting PM characterized by a mass median diameter (MMD) of 20 ?m and a geometric standard deviation (GSD) of 1.5 could be forced to comply with a 3.2 and 14 times more stringent regulation of PM10 and PM2.5, respectively, than a source emitting PM characterized by a MMD of 10 ?m and a GSD of 1.5. These estimates are based on both sources emitting the same concentrations of true PM or concentrations corresponding to the particle diameters less than the size of interest. Various methods were used to estimate the true PM10 and PM2.5 emission factors associated with cotton gin exhausts and the extent to which the sampler errors impacted the PM regulation. Results from this research indicated that current cotton gin emission factors could be over-estimated by about 40%. This over-estimation is a consequence of the relatively large PM associated with cotton gin exhausts. These PM sampling errors are contributing to the misappropriation of source emissions in State Implementation Plans, essentially forcing Air Pollution Regulatory Agencies to require additional controls on sources that may be incorrectly classified has high emitters.