|
|
|
|
|
|
The Online Monitoring System of VOCs Emitted by Stationary Pollution Source Based on FTIR |
Lü Shi-long1, ZHAO Hui-jie1, REN Li-bing2, WANG Xin3, WEI Hao-yun1, LI Yan1* |
1. State Key Laboratory of Precision Measurement Technology and Instruments, Department of Precision Instruments, Tsinghua University, Beijing 100084, China
2. Wuhan Tianhong Environmental Protection Industry Co., Ltd., Wuhan 430223, China
3. College of Mechanical Engineering and Applied Electronics Technology, Beijing University of Technology, Beijing 100124, China |
|
|
Abstract VOCs (Volatile organic compounds) not only cause global environmental pollution, but also have negative impact on people’s daily life. Efficient and accurate monitoring of VOCs has become a hot issue in China’s atmospheric environment governance. Compared with other gaseous pollutants, VOCs are more volatile and easily react with other gaseous pollutants. The complexity of their physical and chemical characteristics sets higher requirements on existing detection methods. Among various gas detection methods, spectral detection technology has been widely used due to its advantages of convenience, rapidity, and accuracy. As an important spectrum detection technology, FTIR (Fourier transform infrared spectroscopy) is multi-channel, which could analyze hundreds of pollutants and calculate real-time pollutant concentrations as well, solving the problems caused by the complex nature of VOCs gas. This paper has tested the online monitoring system of VOCs emitted by stationary pollution source, which is based on FTIR. The infrared interference signal emitted by the interferometer is absorbed by the target gas in the 10-m path length gas pool and subjected to Fourier Transform to obtain the infrared spectrum containing the characteristic absorption peak of the gas. In addition, the comparison between the infrared spectrum and standard database helps with identification of the target gas and concentration measurement. This system covers a spectral range of 650~4 000 cm-1. Since most VOCs have relatively independent absorption peaks in the mid-infrared fingerprint area, the analysis of multiple gases can be completed with a spectral resolution of 1 cm-1 and a concentration detection range of 1.6~319.47 mg·m-3 (Take Benzene as an example). What’s more, the system analyzes and tests dozens of VOCs, such as toluene, acetone, and ethyl acetate, obtaining infrared spectra of different gases, which coincides well with the standard database and can be differentiated according to the absorption peaks of different gases. In order to obtain the exact gas concentration, instruments need calibration as well as to reduce the adsorption of gas in the inner chamber and the mirror and control the water vapor content, a temperature control system is added to monitor the temperature of the gas pool in real time. Meanwhile, with xylene standard gas with different concentrations inflated, this experiment uses the five-point calibration method to obtain the relationship between the analytical concentration and the standard concentration, leading to a relative deviation of the analytical concentration less than 0.06%. To verify the performance of the system in actual working scenario, this paper selects a coating workshop to monitor the VOCs pollution caused by volatilization of solvents and diluents in coating process for one week obtaining concentration changes of benzene, methyl ethyl ketone, isopropyl alcohol and ethyl acetate. Concentration safety threshold is set to guarantee safe operations. From the long-time data analysis, the system MTBF (Mean Time Between Failure) is as long as 1 000 h, which provides a lasting, stable and reliable real-time monitoring.
|
Received: 2018-04-19
Accepted: 2018-08-08
|
|
Corresponding Authors:
LI Yan
E-mail: liyan@mail.tsinghua.edu.cn
|
|
[1] Griffiths A D, Houwing A F. Applied Optics, 2005, 44(31): 6653.
[2] Gieseler H, Kessler W J, Finson M, et al. Journal of Pharmaceutical Sciences, 2007, 96(7): 1776.
[3] Witzel O, Klein A, Meffert C, et al. Opt. Express, 2013, 21:19951.
[4] Witzel O, Klein A, Wagner S, et al. Applied Physics B, 2012, 109(3):521.
[5] Svensson T, Lewander M, Svanberg S. Optics Express, 2010, 18(16): 16460.
[6] Chaffin C T, Marshall T L, Combs R J, et al. Proc. SPIE, Optical Sensing for Environmental and Process Monitoring, 1995, 2365: 302(doi: 10.1117/12.210804).
[7] Modiano S H, Mcnesby K L, Marsh P E, et al. Applied Optics, 1996, 35(21):4004.
[8] Piccot S D, Masemore S S, Ringler E S, et al. Air & Waste Management Association, 1994, 44: 3, 271(doi: 10.1080/1073161X.1994.10467254).
[9] Speitel L C. Journal of Fire Sciences, 2002, 20(5): 349.
[10] Griffiths P R, Haseth J A D. Fourier Transform Infrared Spectrometry, 2nd ed. New Jersey: John Wiley & Sons. Inc., 2007.
[11] LIU Wen-qing, LIU Jian-guo, XU Liang, et al(刘文清,刘建国,徐 亮,等). Modern Scientific Instruments(现代科学仪器), 2016, 6:10.
[12] WANG Jun-bo, WANG Xin, WEI Hao-yun, et al(王君博,王 昕,尉昊赟,等). Laser Technology(激光技术), 2017, 41(2): 163.
[13] REN Li-bing, WEI Hao-yun, LI Yan(任利兵,尉昊赟,李 岩). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2011, 31(4):997. |
[1] |
YANG Wen-feng1, LIN De-hui1, CAO Yu2, QIAN Zi-ran1, LI Shao-long1, ZHU De-hua2, LI Guo1, ZHANG Sai1. Study on LIBS Online Monitoring of Aircraft Skin Laser Layered Paint Removal Based on PCA-SVM[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2023, 43(12): 3891-3898. |
[2] |
HU Yun-you1, 2, XU Liang1*, XU Han-yang1, SHEN Xian-chun1, SUN Yong-feng1, XU Huan-yao1, 2, DENG Ya-song1, 2, LIU Jian-guo1, LIU Wen-qing1. Adaptive Matched Filter Detection for Leakage Gas Based on Multi-Frame Background[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2022, 42(10): 3307-3313. |
[3] |
ZHA Ling-ling1, 2, 3, WANG Wei2*, XIE Yu1, SHAN Chang-gong2, ZENG Xiang-yu2, SUN You-wen2, YIN Hao2, HU Qi-hou2. Observation of Variations of Ambient CO2 Using Portable FTIR
Spectrometer[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2022, 42(04): 1036-1043. |
[4] |
HU Guo-qing1, 2, GUAN Ying-chun1, 2, 3*. Research Progress of Spectral Measurement on the On-Line Monitoring of Laser Processing[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2021, 41(08): 2343-2356. |
[5] |
HU Rong1,2,LIU Wen-qing2,XU Liang2*,JIN Ling2,YANG Wei-feng2,SHEN Xian-chun2,CHENG Xiao-xiao2, WANG Yu-hao2,HU Kai2,LIU Jian-guo2. Near Infrared Spectroscopic Modeling Method for Cement Raw Meal Components by Eliminating Background Moisture[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2020, 40(04): 1051-1055. |
[6] |
CHEN Yu-nan1,2,3, YANG Rui-fang1,3, ZHAO Nan-jing1,3*, ZHU Wei1, 2,3, HUANG Yao1,2,3, ZHANG Rui-qi1,2,3, CHEN Xiao-wei1,2,3. Experimental Study on Quantitative Detection of Oil Slick Thickness Based on Laser-Induced Fluorescence[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2019, 39(11): 3646-3652. |
[7] |
XIAO Hu-ying1, YANG Fan1, XIANG Liu1, HU Xue-jiao2*. Jet Vacuum Enhanced Tunable Diode Laser Absorption Spectroscopy[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2019, 39(10): 2993-2997. |
[8] |
CHEN Ying1, HE Lei1, CUI Xing-ning1, HAN Shuai-tao1, ZHU Qi-guang2, ZHAI Ying-jian3, LI Shao-hua3. Study on Mixed Prediction Model of Nitrate Concentration in Water Based on Ultraviolet Spectroscopy[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2019, 39(05): 1489-1494. |
[9] |
XU Xing-wei1, 2, WANG Wei1*, LIU Cheng3, SHAN Chang-gong4, SUN You-wen1, HU Qi-hou1, TIAN Yuan1, HAN Xue-bing1, YANG Wei1. Observations of Total Columns of CO Based on Solar Absorption Spectra[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2018, 38(05): 1329-1334. |
[10] |
ZHAO Yan1*, WANG An-lin1, CHENG Nian-shou2, LI Zhong-yan1, ZHU Chang-wei1, CAI Chuan-jie1 . Quantitive Analysis of Contents in Yogurt and Application Research with FTIR Spectroscopy [J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2016, 36(12): 3937-3940. |
[11] |
SHI Lei1,LIU Jia2,GAO Wu1,ZHANG Qian-xuan1,WANG Wei1. The Design of an ATR Probe for Online Monitoring of Biological Process[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2016, 36(06): 1954-1958. |
[12] |
LI Dan1, FENG Wei-wei2*, CHEN Ling-xin2, ZHANG Jun1* . An On-Line Monitoring System for Nitrate in Seawater Based on UV Spectrum[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2016, 36(02): 442-444. |
[13] |
WAN Fu, CHEN Wei-gen, GU Zhao-liang, ZOU Jing-xin, DU Ling-ling, QI Wei, ZHOU Qu . Measurement of Trace C2H6 Based on Optical-Feedback Cavity-Enhanced Absorption Spectroscopy[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2015, 35(10): 2792-2796. |
[14] |
XIE Fei, WU Qiong-shui*, ZENG Li-bo* . Biological Process Oriented Online Fourier Transform Infrared Spectrometer[J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2015, 35(08): 2357-2361. |
[15] |
ZHAO An-xin1, 2, TANG Xiao-jun1*, WANG Er-zhen1, ZHANG Zhong-hua1, 3, LIU Jun-hua1 . Quantitative Analysis of Transformer Oil Dissolved Gases Using FTIR [J]. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2013, 33(09): 2407-2410. |
|
|
|
|