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.
Engine manufacturers conduct emissions reduction research using test equipment that feeds a simulated automotive exhaust stream through candidate emissions abatement technologies. Once it has passed through the abatement system, the gas stream is analyzed to determine the efficiency with which the technology eliminates pollutants. Electronic mass flow controllers (MFCs) are used to produce the different gas mixtures that simulate the exhaust gas composition for a wide range of conditions. Precise knowledge of the independent operating parameters in an engine, the fuel formulation, and the chemical composition of the exhaust gas stream before and after the abatement technology enables the development of chemometric models that can be used to minimize engine emissions while maintaining acceptable performance. Robust chemometric modeling is only enabled if there are very low levels of variation in the controlled inputs. This demands precise, accurate and reproducible MFC calibration.
Mass Flow Control
The MKS G-Series Mass Flow Controller Platform provides the reproducibility and low calibration variability that is required by emission reduction catalyst manufacturers, engine OEMs, universities, and government agencies. This is directly due to the G-Series MFC’s fully traceable automated calibration process with 6 sigma process capability.
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.
As a locomotive emission analyzer, the MultiGas™ 2030 measures combustion gases by incorporating a fast scanning FTIR capable of providing high resolution locomotive exhaust data. It allows locomotive exhaust to flow through at high rates to prevent diffusion and measurement delay. The software and computer hardware provided with each system are optimized to allow for 20-plus gases to be quantified simultaneously and reported for continuous locomotive emissions 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.
The MultiGas 2030 is an FTIR-based gas analyzer capable of directly measuring ppm to ppb levels of CO, NO, NO2 , CH2O (formaldehyde), NH3 , SO2 , N2 O, methane and other hydrocarbons, in sample streams containing up to 30% H2O and CO2 . This enables complete exhaust gas measurement on wet streams with minimal sample conditioning. The 2030 provides simultaneous analysis and display of more than 30 gases in real-time that include ppm to sub-ppm levels of both formaldehyde and ammonia. For example, the MultiGas 2030 can detect 100 ppb ammonia from SCR scrubbers, even in gas streams with high % levels of H2O and CO2. The ability to simultaneously detect most combustion byproducts, allows for the replacement of several single gas analyzers racks into a single compact instrument. Also, the permanently stored spectral calibration data, for each gas species, reduces the need for continuous calibration checks and the quantity of gas cylinders.