Section 117.8130 - Ammonia MonitoringWhen required by this chapter, one of the following ammonia monitoring procedures must be used to demonstrate compliance with the applicable ammonia emission specifications of this chapter for gas-fired or liquid-fired units that inject urea or ammonia into the exhaust stream for nitrogen oxides (NOX) control.
(1) Mass balance. Ammonia emissions are calculated as the difference between the input ammonia, measured by the ammonia injection rate, and the ammonia reacted, measured by the differential NOX upstream and downstream of the control device that injects urea or ammonia into the exhaust stream. The ammonia emissions must be calculated using the following equation. Attached Graphic
(2) Oxidation of ammonia to nitric oxide (NO). Convert ammonia to NO using a molybdenum oxidizer and measure ammonia slip by difference using a NO analyzer. The NO analyzer must be quality assured in accordance with the manufacturer's specifications and with a quarterly cylinder gas audit with a 10 parts per million by volume (ppmv) reference sample of ammonia passed through the probe and confirming monitor response to within ± 2.0 ppmv.(3) Stain tubes. Measure ammonia using a sorbent or stain tube device specific for ammonia measurement in the 5.0 to 10.0 ppmv range. The frequency of sorbent/stain tube testing must be daily for the first 60 days of operation. After the first 60 days of operation, the frequency may be reduced to weekly testing if operating procedures have been developed to prevent excess amounts of ammonia from being introduced in the control device and when operation of the control device has been proven successful with regard to controlling ammonia slip. Daily sorbent or stain tube testing must resume when the catalyst is within 30 days of its useful life expectancy. Every effort must be made to take at least one weekly sample near the normal highest ammonia injection rate.(4) Other methods. Monitor ammonia using another continuous emissions monitoring system or predictive emissions monitoring system procedure subject to prior approval of the executive director.30 Tex. Admin. Code § 117.8130
The provisions of this §117.8130 adopted to be effective June 14, 2007, 32 TexReg 3206