Simultaneous Quantitative Detection of HCN and C2H2 in Combustion Environment Using TDLAS

Abstract

Emission of nitrogen oxides (NOx) and soot particles during the combustion of biomass fuels and municipal solid waste is a major environmental issue. Hydrogen cyanide (HCN) and acetylene (C2H2) are important precursors of NOx and soot particles, respectively. In the current work, infrared tunable diode laser absorption spectroscopy (IR-TDLAS), as a non-intrusive in situ technique, was applied to quantitatively measure HCN and C2H2 in a combustion environment. The P(11e) line of the first overtone vibrational band v1 of HCN at 6484.78 cm−1 and the P(27e) line of the v1 + v3 combination band of C2H2 at 6484.03 cm−1 were selected. However, the infrared absorption of the ubiquitous water vapor in the combustion environment brings great uncertainty to the measurement. To obtain accurate temperature-dependent water spectra between 6483.8 and 6485.8 cm−1, a homogenous hot gas environment with controllable temperatures varying from 1100 to 1950 K provided by a laminar flame was employed to perform systematic IR-TDLAS measurements. By fitting the obtained water spectra, water interference to the HCN and C2H2 measurement was sufficiently mitigated and the concentrations of HCN and C2H2 were obtained. The technique was applied to simultaneously measure the temporally resolved release of HCN and C2H2 over burning nylon 66 strips in a hot oxidizing environment of 1790 K.

Application and algorithm research of TDLAS

“…The micro TDLAS system was placed on fixed-wing and multi-rotor, the absolute percentage difference between the measurements of the fixed-wing long-term UAV was below 16%, and the average error was 6%, which proved the adaptability of hypersensitized micro-spectrometer in defining CH4 discharge [13]. Wubin Weng et al used infrared-TDLAS (IR-TDLAS) as the non-invasive in-situ measurement means and determine hydrogen cyanide and ethyne in combustion environments [14].…”

Quantification of Elevated Hydrogen Cyanide (HCN) Concentration Typical in a Residential Fire Environment Using Mid-IR Tunable Diode Laser

“…These measurement methods utilize HCN absorption lines in the near infrared region of the electromagnetic spectrum. [24][25][26][27] With the increased availability of tunable diode lasers in the mid-infrared (mid-IR) region, it has become possible to utilize the much stronger fundamental vibration bands of HCN in the mid-IR region. Absorption lines from the fundamental C-H stretching band have been used to quantify HCN using various mid-IR spectroscopy techniques such as mid-IR polarization spectroscopy in atmospheric pressure flames 28 and mid-IR degenerate four-wave mixing in gasified biomass pellets.…”

Research on Improved Quantitative Identification Algorithm in Odor Source Searching Based on Gas Sensor Array

“…In today’s era of rapid development of various technologies, the quantitative detection and analysis of gas have broad application prospects in the fields of food science, environmental science, public security, and national defense and military [ 1 , 2 , 3 ]. Due to the widespread disadvantages of cross sensitivity and selectivity difference, it is difficult to realize the detection and analysis of mixed gases with a single sensor [ 4 ].…”