TransForum Vol. 9, No. 2

Facility Spotlight: Fourier Transform Infrared Spectrometer (FTIR)
A Nimble Tool Repurposed

The FTIR can provide detailed real-time measurements for up to 25 different exhaust components at the same time.

Chemists have traditionally used the Fourier Transform Infrared (FTIR) Spectrometer System on the chemical benchtop to measure hydrocarbons, ammonia and nitrogen oxides. Argonne’s creative transportation engineers have now found a new use for this instrument in the Laboratory’s Advanced Powertrain Research Facility to measure vehicle exhaust emissions as well.

"This tool is needed to test new fuels, to determine if a new fuel is practical and not toxic,” said Henry Ng, mechanical engineer and chief fuels researcher. “This is an optical measurement instrument that can analyze up to 25 different exhaust components simultaneously, including measuring nitrogen oxide (NOx) in the presence of ammonia.”

Since plug-in hybrid electric vehicle emissions are lower than emissions from gasoline powered vehicles, a specialized tool that can measure the smaller amounts is needed. “The main advantage is that the FTIR can measure raw, undiluted exhaust at a much lower, granular level,” said Ng. “More groups of chemicals are collected with the raw exhaust, since they haven’t been diluted out. These include greenhouse gases—especially nitrous oxide—as well as hydrocarbons, nitrogen oxides, aldehydes and ammonia.”

The portable FTIR is on casters and can be moved to various test cells as needed. It has also been used to measure the engine exhaust emissions of butanol and ethanol. In addition, two other Argonne test facilities are using the FTIR: the Engine Research Facility has used it to measure emissions from natural gas combustion, and the Locomotive Engine Research Facility successfully used it to measure NOx in the presence of ammonia.

October 2009