Mid-infrared fiber-coupled laser absorption sensor for simultaneous NH3 and NO monitoring in flue gases

Duan, Kun; Ji, Yongbin; Wen, Daxin; Lü, Zhimin; Xu, Ke; Ren, Wei

doi:10.1016/j.snb.2022.132805

Cited by 24 publications

(9 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The composition of the exhaust gas in industrial systems was typically monitored using flue gas analyzers, [5][6][7] gas chromatography (GC), 8,9 and tunable diode laser absorption spectroscopy (TDLAS). [10][11][12][13][14][15][16] In flue gas analyzers, the concentration of gas entering the sensor through a sampling tube is estimated by an electrochemical sensor array, while in GC, the concentration of each gas that make up the sample is measured with a detector after being separated by a porous column. These methods, i.e., Fourier transform infrared spectroscopy and GC, can measure concentrations of various gases simultaneously, but require gas sampling, making real-time measurements difficult.…”

Section: Introductionmentioning

confidence: 99%

Carbon Dioxide Concentration Estimation in Nonuniform Temperature Fields Based on Single-Pass Tunable Diode Laser Absorption Spectroscopy

Choi,

Bong,

Yoo

et al. 2023

Appl Spectrosc

View full text Add to dashboard Cite

We propose a novel technique to accurately predict carbon dioxide (CO2) concentrations even in flow fields with temperature gradients based on a single laser path absorption spectrum measurement and machine learning. Concentration measurements in typical tunable diode laser absorption spectroscopy are based on a ratio of two integrated absorbances, each from a spectral line with different temperature dependence. However, the inferred concentrations can deviate significantly from the actual concentrations in the presence of temperature gradients. Furthermore, it is also difficult to find an analytical expression to compensate for the effect of nonuniform temperature profiles on concentration measurements. In this study, the entire absorption feature was considered since its shape and peak intensities vary with temperature and concentration. Specifically, a predictive model is obtained in a data-driven manner that can identify and compensate for the effect of a nonuniform temperature field on the spectrum. Despite a very detailed understanding of the CO2 absorption spectrum, it is nearly impossible to collect sufficient spectra for model acquisition by varying all temperature gradient conditions. Therefore, the model was obtained using only simulated data, much like the concept of a “digital twin”. Finally, the predictive performance of the acquired model was verified using experimental data. In all test cases, the predictive performance of the model was superior to that of the two-line method. Additionally, a gradient-weighted regression activation mapping analysis confirmed that the model utilizes both the peak intensities as well as the change in the shape of absorption lines for prediction.

show abstract

Section: Introductionmentioning

confidence: 99%

Carbon Dioxide Concentration Estimation in Nonuniform Temperature Fields Based on Single-Pass Tunable Diode Laser Absorption Spectroscopy

Choi,

Bong,

Yoo

et al. 2023

Appl Spectrosc

View full text Add to dashboard Cite

show abstract

“…In addition, accurate measurement of NO using LAS is also challenging because the candidate NO absorption features were contributed by many multifold transitions, [27][28][29] introducing the difficulty in accurate fitting of the absorption feature with high efficiency. 30 In this work, a mid-infrared laser-based sensor was developed for calibration-free and minimally intrusive measurement of NO in methane-ammonia cofired flames. An interband cascade laser was adopted to cover the spectra of NO centered at 1900.07 cm −1 .…”

Section: Introductionmentioning

confidence: 99%

“…It is important to mention that extended sampling time while using the MPGC will contribute to distorted results as NO can react with O 2 . In addition, accurate measurement of NO using LAS is also challenging because the candidate NO absorption features were contributed by many multifold transitions, 27–29 introducing the difficulty in accurate fitting of the absorption feature with high efficiency 30 …”

Section: Introductionmentioning

confidence: 99%

A mid‐infrared laser absorption sensor for calibration‐free measurement of nitric oxide in laminar premixed methane/ammonia cofired flames

Jiang

Wang

et al. 2023

Micro & Optical Tech Letters

View full text Add to dashboard Cite

An interband cascade laser (ICL)‐based absorption sensor was developed for calibration‐free and high‐fidelity measurement of nitric oxide (NO) in laminar premixed methane/ammonia cofired flames using a combination of a micro‐probe and a low‐pressure, high‐temperature gas cell. The developed sensor, which has been shown to be particularly suitable for kinetic studies of ammonia combustion, used a tunable, continuous, narrow‐linewidth, free‐space ICL operating at ~5.2 μm to target the optimal NO transition centered at 1900.07 cm−1. A direct absorption spectroscopy technique with a reduced line model was implemented for calibration‐free measurements. Comprehensive experiments were first conducted to evaluate the sensor performance against the standard gas mixture at varied pressure from 20 to 101 kPa at 393 K, showing a relative difference of ≤2.5% and a measurement uncertainty of ≤2.0%. Such a sensor shows a minimum detection limit of ~2 ppm at the integration time of 1 s. The sensor was then applied for investigating the NO formation in ammonia‐methane cofiring flames with various ammonia blending ratios; the acquired experimental data was further used as benchmark data for evaluation of literature chemical mechanisms for ammonia combustion. The developed sensor system was demonstrated to be capable of providing quantitative and spatially resolved measurement of NO in ammonia‐methane cofired flames.

show abstract

“…A QEPAS sensor for detecting H 2 S gas in the mid-infrared (MIR) region was established, which achieved a high sensitivity of the ppb level of H 2 S gas in the N 2 background . The absorption coefficient of the gas in the fundamental frequency region is 3 orders of magnitude higher than that in the overtone region . However, the high cost and low maturity of MIR lasers restrict their application.…”

mentioning

confidence: 99%

“…16 The absorption coefficient of the gas in the fundamental frequency region is 3 orders of magnitude higher than that in the overtone region. 17 However, the high cost and low maturity of MIR lasers restrict their application. In 2015, Dong and co-workers developed an enhanced QEPAS sensor for H 2 S in the N 2 background detection using a QTF with a bifurcated spacing of 800 μm and an erbium-doped fiber amplifier (EDFA).…”

mentioning

confidence: 99%

Multi-pass Differential Photoacoustic Sensor for Real-Time Measurement of SF₆Decomposition Component H₂S at the ppb Level

et al. 2023

View full text Add to dashboard Cite

We designed and implemented a photoacoustic (PA) sensor for H 2 S detection in SF 6 background gas based on a multi-pass differential photoacoustic cell (MDPC) and a near-infrared distributed feedback (DFB) laser. In the MDPC apparatus, two resonators with identical geometric parameters were vertically and symmetrically embedded. The differential processing algorithm of two phase-reversed signals realized the effective enhancement of the PA signal and suppressed the flow noise in the dynamic sampling process. In addition, the λ/4 buffer chamber in the MDPC was utilized as a muffler to further reduce the flow noise and realize the dynamic detection of H 2 S. The collimated excitation light was reflected 30 times in a multi-pass structure constituted of two gold-plated concave mirrors, and an absorption path length of 4.92 m was achieved. Due to the high gas density of SF 6 , the relationship between the signal-to-noise ratio (SNR) and the gas flow was different between SF 6 and N 2 background gases. The maximum flow rate of the characteristic gas components detected in the SF 6 background is 150 standard cubic centimeters per minute (SCCM), which is lower than 350 SCCM in N 2 . The linearity property was analyzed, and the results show that the sensitivity of the sensor to H 2 S in the SF 6 background was 27.3 μV/ppm. With the structure, parameters, temperature, gas flow, and natural frequency of the MDPC been optimized, a minimum detection limit (MDL) of 11 ppb was reached with an averaging time of 1000 s, which furnished an effective preventive implement for the safe operation of gas insulation equipment.

show abstract

Mid-infrared fiber-coupled laser absorption sensor for simultaneous NH3 and NO monitoring in flue gases

Cited by 24 publications

References 36 publications

Carbon Dioxide Concentration Estimation in Nonuniform Temperature Fields Based on Single-Pass Tunable Diode Laser Absorption Spectroscopy

Carbon Dioxide Concentration Estimation in Nonuniform Temperature Fields Based on Single-Pass Tunable Diode Laser Absorption Spectroscopy

A mid‐infrared laser absorption sensor for calibration‐free measurement of nitric oxide in laminar premixed methane/ammonia cofired flames

Multi-pass Differential Photoacoustic Sensor for Real-Time Measurement of SF₆Decomposition Component H₂S at the ppb Level

Contact Info

Product

Resources

About

Mid-infrared fiber-coupled laser absorption sensor for simultaneous NH3 and NO monitoring in flue gases

Cited by 24 publications

References 36 publications

Carbon Dioxide Concentration Estimation in Nonuniform Temperature Fields Based on Single-Pass Tunable Diode Laser Absorption Spectroscopy

Carbon Dioxide Concentration Estimation in Nonuniform Temperature Fields Based on Single-Pass Tunable Diode Laser Absorption Spectroscopy

A mid‐infrared laser absorption sensor for calibration‐free measurement of nitric oxide in laminar premixed methane/ammonia cofired flames

Multi-pass Differential Photoacoustic Sensor for Real-Time Measurement of SF6Decomposition Component H2S at the ppb Level

Contact Info

Product

Resources

About

Multi-pass Differential Photoacoustic Sensor for Real-Time Measurement of SF₆Decomposition Component H₂S at the ppb Level