NOx emission issues have been of significant interest to the glass industry in recent years. The glass industry recognises that it must provide reasonable assurance that their facilities comply with established NOx emissions standards imposed by air pollution control agencies, but wish to avoid continuous emission monitoring systems (CEMS) because of their significant capital investment and high operating and maintenance costs. This paper reviews the industry's alternative predictive emission monitoring system (PEMS) approach, which can meet the requirements imposed on CEMS, minimizing the additional purchase and maintenance costs. Appropriate furnace parameters are selected for predictive calculations of NOx emissions developed from the periodic monitoring with a portable chemical cell gas analyser. Commercial portable analysers now have the ability to provide precise and accurate measurements similar to CEMS when properly operated according to approved test protocols. The systems effectiveness for each operation furnace can be validated by comparing emission test method data with simultaneous parameter monitoring data. Resultant predictive calculations have been accepted by air emission control agencies for demonstrating regulation compliance.
