"In-situ" Analysis of High Temperature Gases by Infrared Spectroscopy and Its Application

Abstract

A technique for the "in-situ" analysis of the high temperature gases containing CO, CO₂, H₂O and SiO at 800-1 600°C was developed. The gas in the furnace was monitored by a newly developed infrared optical sensor with Fourier Transform Infrared Spectrometer (FTIR). The sensor was of a water cooled probe with various infrared light guide.
The experimental results could be summarized as follows;
(1) Partial pressure of CO, CO₂ and H₂O could be measured at 800-1600°C by the infrared optical sensor. The maximum sensitivity of this technique was as high as 0.0001atm (100ppm) of CO gas with optical depth of 200mm at 1 550°C.
(2) Infrared absorption spectrum of unstable SiO gas was measured by the infrared optical sensor demonstrating the possibility of measuring the partial pressure of SiO.
(3) It was demonstrated that those gas species evolved during the reduction of cold-bonded pellet by CO or H₂ gas was quantitatively analyzed.
(4) "In-situ" analysis technique was applied to the pilot plant scale combustion test furnace. Change of gas composition with pulverized coal injection could be accurately monitored in the combustion furnace.