Carbon Monoxide Sensor for Combustion Feedback Control

Abstract

A sensor for carbon monoxide detection based on broadband absorption spectroscopy with a gas correlation filter is developed using a miniaturized light source and detector without the need of a mechanical chopper to alternate between two gas correlation cells into the optical path. Measurements were conducted using calibrated CO/N 2 mixtures and sampled combustion products from a diffusion flame. The detection sensitivity was found to be 100 ppm for the measured range of 100 to 500 ppm. The sensor can be used to control individual burners in small scale combustion systems in order to maintain combustion efficiency and minimize pollutant emissions during their operation life cycle.

Review of Dissolved CO and H2 Measurement Methods for Syngas Fermentation

“…Interference occurs when other chemicals also absorb infrared radiation at the same wavelength for CO measurement. Therefore, NDIR sensors require narrowband infrared filters [ 100 ] or gas filter correlation techniques [ 109 ] to exclude infrared radiations outside the CO detection wavelength from broadband infrared sources.…”

“…Nondispersive infrared (NDIR) sensors are designed to compare the incident and transmitted infrared radiation through gas samples to measure CO concentration [ 100 ]. Double beam design [ 110 ] and single beam design with the gas correlation filter [ 109 ] were the mostly reported sensor configurations ( Figure 2 ).…”

“…Thus, the time required for gas extraction can be shorter when only a tiny amount of liquid sample is analyzed. Nondispersive infrared (NDIR) sensors and photoacoustic sensors were reported with inferior detection limits at the ppm level [ 100 , 226 ], but they can be applicable when the gas extraction system can handling large volume of sample in short time, such as system built with a hollow fiber membrane contactor [ 147 , 227 ].…”

“…Common infrared spectroscopy instruments include dispersive spectrometers, Fourier transform infrared (FTIR) spectroscopy, nondispersive infrared (NDIR) sensors, and tunable diode laser absorption spectroscopy (TDLAS) sensors [98]. NDIR and TDLAS sensors are dedicate instruments to measure the attenuation of infrared radiation at certain, narrow spectra range, which makes them the most prevailing CO infrared measurement techniques due to their simplicity, robustness, and accuracy [99][100][101]. Dispersive and FTIR spectrometers can measure multiple gases simultaneously as they are capable to obtain infrared absorption spectra in a wide spectral range [102][103][104].…”

“…where I o represents the intensity (W/sr) of incident infrared radiation, I represents the intensity (W/sr) of infrared radiation transmitted through the gas cell, ε represents the gas's molar attenuation coefficient (cm −1 mol −1 •L), and L represents the optical pathlength (cm) of the gas cell. − Nondispersive Infrared Sensors Nondispersive infrared (NDIR) sensors are designed to compare the incident and transmitted infrared radiation through gas samples to measure CO concentration [100]. Double beam design [110] and single beam design with the gas correlation filter [109] were the mostly reported sensor configurations ( Figure 2).…”