METHOD 204B-VOLATILE ORGANIC COMPOUNDS EMISSIONS IN CAPTURED STREAM 1. Scope and Application 1.1 Applicability. This procedure is applicable for determining the volatile organic compounds (VOC) content of captured gas streams. It is intended to be used in the development of a gas/gas protocol for determining VOC capture efficiency (CE) for surface coating and printing operations. The procedure may not be acceptable in certain site-specific situations [e.g., when: (1) directfired heaters or other circumstances affect the quantity of VOC at the control device inlet; and (2) particulate organic aerosols are formed in the process and are present in the captured emissions]. 1.2 Principle. The amount of VOC captured (G) is calculated as the sum of the products of the VOC content (CG), the flow rate (QGj), and the sample time (c) from each captured emissions point. 1.3 Sampling Requirements. A CE test shall consist of at least three sampling runs. Each run shall cover at least one complete production cycle, but shall be at least 3 hours long. The sampling time for each run need not exceed 8 hours, even if the production cycle has not been completed. Alternative sampling times may be used with the approval of the Administrator. analyzer. The sample line must be heated to prevent condensation. 4.1.4 Sample Pump. A leak-free pump, to pull the sample gas through the system at a flow rate sufficient to minimize the response time of the measurement system. The components of the pump that contact the gas stream shall be constructed of stainless steel or Teflon. The sample pump must be heated to prevent condensation. 4.1.5 Sample Flow Rate Control. A sample flow rate control valve and rotameter, or equivalent, to maintain a constant sampling rate within 10 percent. The flow rate control valve and rotameter must be heated to prevent condensation. A control valve may also be located on the sample pump bypass loop to assist in controlling the sample pressure and flow rate. 4.1.6 Organic Concentration Analyzer. An FIA with a span value of 1.5 times the expected concentration as propane; however, other span values may be used if it can be demonstrated to the Administrator's satisfaction that they would provide equally accurate measurements. The system shall be capable of meeting or exceeding the following specifications: 4.1.6.1 Zero Drift. Less than ±3.0 percent of the span value. 4.1.6.2 Calibration Drift. Less than 13.0 percent of the span value. 4.1.6.3 Calibration Error. Less than £5.0 percent of the calibration gas value. 4.1.6.4 Response Time. Less than 30 seconds. 4.1.7 Integrator/Data Acquisition System. An analog or digital device, or computerized data acquisition system used to integrate the FIA response or compute the average response and record measurement data. The minimum data sampling frequency for computing average or integrated values is one measurement value every 5 seconds. The device shall be capable of recording average values at least once per minute. 4.2 Captured Emissions Volumetric Flow Rate. 4.2.1 Method 2 or 2A Apparatus. For determining volumetric flow rate. 4.2.2 Method 3 Apparatus and Reagents. For determining molecular weight of the gas stream. An estimate of the molecular weight of the gas stream may be used if approved by the Administrator. 4.2.3 Method 4 Apparatus and Reagents. For determining moisture content, if nec essary. 5. Reagents and Standards 5.1 Calibration and Other Gases. Gases used for calibration, fuel, and combustion air (if required) are contained in compressed gas cylinders. All calibration gases shall be traceable to National Institute of Standards and Technology standards and shall be certified by the manufacturer to +1 percent of |