Pollution control is a critical global challenge. Governments across the world have legislated clean air requirements for stationary and mobile engines in cars, trucks, trains, and marine vessels. Facilities such as power plants, manufacturing buildings, incinerators, etc. emit significant amounts of pollutants from their smoke stacks. Evaluating the exhaust from these stacks is vital to ensure compliance with air quality laws and regulations.
Locomotive Engine Testing monitors traditional and nontraditional diesel combustion gases from locomotive engines in less than a second. There are few products that can monitor locomotive engine diesel exhaust in a time frame and level necessary to be practical.
Locomotive engine regulations from United States and other governments and environmental locomotive exhaust concerns have lead locomotive engine manufacturers to monitor and test locomotive diesel exhaust. To address the demand for fast, accurate locomotive engine emission analysis, FTIR analyzers can measure exhaust gas generated by locomotive engines, and current versions are fast and sensitive enough to perform continuous locomotive exhaust analysis.
Historically, combustion exhaust is analyzed for species such as O2, SO2, CO2, CO, total hydrocarbons, NO, and NO2 using multiple single gas analyzers. These individual analyzers have a high initial cost, continuing maintenance cost and cannot measure wet sample streams, so sample condition systems must be installed to remove moisture. The conditioning process can affect the measurement quality and remove compounds of interest. In addition, current combustion analyzers cannot monitor all combustion by-products suggested or required by changes in environmental regulations, including formaldehyde, which has traditionally been difficult to monitor in real time.
Tightening regulations on NOx emissions from stationary combustion sources has brought about the development of Selective Catalytic Reduction (SCR) technologies. These technologies are driving NOx emissions to low single digit ppm levels or below. This reduction is not without some drawbacks to emissions in that ammonia is commonly used by the SCR. Normally, ammonia levels can vary from tens of ppm to tens of ppb, but if not balanced correctly the process results in significant ammonia slip. One current method to monitor ammonia relies on catalytic conversion of NH3 to NO, which is then analyzed using traditional chemiluminescence NOx analyzers. This indirect measurement of ammonia adds a significant level of complexity and uncertainty, and current analyzers have limited accuracy below a ppm. New technology needs to be provided that will provide 100 ppb NH3 monitoring directly and in real-time.