Gas composition using THz spectroscopy

Purpose and goal:

Spectroscopic experiments were performed within 0.050 to 1.280 THz on gases typical of the metallurgical industry. Spectra were measured at different concentrations and at different temperatures from room temperature up to 900 ° C. The spectroscopic experiments began with theoretical simulations of spectra compared with the experimental results.

Spectra could be detected for carbon monoxide and water vapor at different temperatures. There were also hopes of being able to measure oxygen and nitric oxide, but spectra are not obtained for those gases. Expected results and effects:

Spectra of carbon monoxide could be detected at different temperatures and concentrations. Spectra were also obtained from water vapor. When oxygen was not detected, the oxygen potential could not be determined.

There was a hope that the content of carbon monoxide and oxygen together with the temperature could give the total amount of carbon in a process gas. In order for this to be fulfilled, a method of detecting oxygen or directly detecting carbon dioxide must be found. Then the amount of carbon in a process gas can be used as a control parameter for process optimization and energy saving.

Approach and implementation:

Proposal began by finding a suitable instrument for the THz waves and identifying the possibility of rebuilding a suitable furnace for gas heating and spectrometer mounting. At the same time as the conversion was carried out, theoretical simulations of molecular spectra were performed on gases that are typical of the metallurgical industry and of importance in terms of process control and resource efficiency.

The planned experiments were performed and the experimental results were compared with theoretical simulations.