Dong Wei, Sugai Yuichi, Wang Yongjun, Zhang Hemeng, Zhang Xiaoming, Sasaki Kyuro
Department of Earth Resources Engineering, Kyushu University, Fukuoka 819-0395, Japan.
College of Safety Science and Engineering, Liaoning Technical University, Huludao 125105, China.
ACS Omega. 2024 Apr 26;9(18):19956-19967. doi: 10.1021/acsomega.3c09769. eCollection 2024 May 7.
An optical sensing approach that balances portability with cost efficiency has been designed for the reliable monitoring of fugitive methane (CH) emissions. Employing a LiTaO-based pyroelectric detector integrated with micro-electro-mechanical systems and a broad infrared source, the developed gas sensor adeptly measured CH concentrations with a low limit of detection of about 5.6 ppm and showed rapid response times with consistently under 3 s. Notably, the novelty of our method lies in its precise control and reduction of CH levels, enhanced by wavelet denoising. This technique, optimized through meticulous grid search, effectively mitigated noise interference noticeable at CH levels below 10 ppm. Postdenoising, nonlinear regression analyses based on the modified Beer-Lambert equation returned values of 0.985 and 0.982 for the training and validation sets, respectively. In conclusion, this gas sensor has been shown to be able to meet the requirements for early warning of CH leakage on the surface in various carbon capture, utilization, and storage projects such as enhanced oil or gas recovery projects using CO injection.
一种兼顾便携性与成本效益的光学传感方法已被设计用于可靠监测逃逸性甲烷（CH）排放。所开发的气体传感器采用集成了微机电系统的基于钽酸锂的热释电探测器和宽红外源，能够以约5.6 ppm的低检测限精确测量CH浓度，且响应时间迅速，始终在3秒以内。值得注意的是，我们方法的新颖之处在于通过小波去噪实现了对CH水平的精确控制和降低。该技术通过细致的网格搜索进行优化，有效减轻了在CH水平低于10 ppm时明显的噪声干扰。去噪后，基于修正的比尔-朗伯方程的非线性回归分析在训练集和验证集上分别得到了0.985和0.982的值。总之，这种气体传感器已被证明能够满足在各种碳捕获、利用和存储项目（如使用CO注入的强化石油或天然气开采项目）中对地表CH泄漏进行早期预警的要求。
