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Show A165E713.T 2 temperature threshold under which natural gas combustion is incomplete leading to increased emission levels of CO and formaldehyde. INTRODUCTION Title ill of the 1990 Clean Air Act Amendments (CAAA) designates 189 chemicals or groups of chemicals as hazardous air pollutants (HAPs), and requires the Environmental Protection agency (EPA) to promulgate emission standards based upon maximum achievable control technology for all new and existing industrial major sources of HAPs. As part of Title V of the 1990 CAAA, each major source of regulated air pollutants must also characterize each regulated pollutant that it emits as part of its operating permit. As defmed in the CAAA, a major source of HAPs is any single source, or group of sources, located within a contiguous area and under common control, that emits, or has the potential to emit, 10 tons per year (tpy) or more of anyone listed HAP, or 25 tpy or more of any combination of listed HAPs. A major source of criteria pollutants emits, or has the potential to emit, 100 tpy of a single criteria pollutant (e.g., NOx, CO, S02, VOCs, particulate matter). Under Title ill, electric utility generating stations are to be reviewed separately based upon utility reports which characterize air toxic emissions and health risks posed to the pUblic. The current paper focuses on the results obtained from two natural gas fued combustion turbines used in electric generation and seven turbines used in natural gas pipeline transmission applications. The emissions measurements presented for the utility combustion turbines were performed by Caroot in 1993 for the Electric Power Research Institute's (EPRI) Gas PISCES (Power Plant Integrated Chemical Emissions Study) field measurement project. The Gas PISCES program measured emissions of HAPs from natural gas-fued utility boilers and combustion turbines in response to the three-year utility air emissions study mandated by Title ill of the CAAA. The program was jointly sponsored by EPRI and the Gas Research Institute (GRI). The emissions measurements for the industrial gas turbines were performed by Caroot on behalf of a natural gas pipeline transmission company. In late 1993, Caroot was performing an air emissions characterization program for this pipeline company in order to allow them to prepare emissions inventories for Title V operating permit applications, and to develop compliance monitoring strategies. The air emissions characterization program evaluated selected HAP, VOC and criteria pollutant emissions from a cross section of the transmission company's gas turbines under various operating conditions. As a follow-up to the Gas PISCES program, GRI sponsored the emission measurements on one of the industrial gas turbines owned by the natural gas pipeline company. This turbine was equipped with a dry-low NOx combustor and represented a gas turbine utilizing a NOx control technology for which HAP emissions measurements were previously not characterized. OBJECTIVES The goals and objectives of the air toxics assessment were to: |