Drone-Assisted Fourier-Transform Spectroscopy for Fugitive Emission Sensing

用于逸散发射传感的无人机辅助傅里叶变换光谱

基本信息

批准号：
ST/P00699X/1
负责人：
Derryck Reid
金额：
$ 38.19万
依托单位：
Heriot-Watt University
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2017
资助国家：
英国
起止时间：
2017 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=ST%2FP00699X%2F1
关键词：
Drone Assisted Fourier Transform Spectroscopy

项目摘要

This project is a joint proposal between researchers in Photonics (Reid, Heriot-Watt University) and Robotics (Ramamoorthy, University of Edinburgh). It is a cross-disciplinary collaboration, which is necessary in order to tackle in a new and exciting way the problem of fugitive emissions of methane and volatile hydrocarbons from installations such as refineries, petrochemical plants, carbon-capture and storage facilities and landfill sites. These emissions cost the energy sector up to $5B per year, account for 12% of greenhouse gas emissions and jeopardise worker safety and public health. Our idea uses mid-infrared laser light to sense the presence of hydrocarbons by looking for characteristic absorptions at wavelengths specific to individual chemical species. Such "gas absorption spectroscopy" is far from new, but we will implement it in a radically different way to conventional approaches. Normally, optical gas detection works by transmitting a single-wavelength through a gas and looking for an intensity change. For fugitive emissions sensing, this is implemented using a technique called DIAL, which shines an intense beam into the air and detects the weak backscattering of this light from particles in the air (Mie scattering). By looking for small differences in the backscattered intensity between two closely-spaced wavelengths, DIAL can sense the presence of one (and only one) chemical species. Its main drawbacks are the weakness of the returned light (after all, air is a very poor reflector!) and its sensitivity only to one chemical species in any given set-up.The gold standard for lab-based chemical identification is Fourier-transform spectroscopy (FTS), which uses a source similar to a filament light-bulb to explore absorptions over a massive wavelength range all at once. Sadly, such thermal light sources have very poor beam quality, so cannot be transmitted over the long distances appropriate to environmental sensing. In 2004, Heriot-Watt demonstrated that broadband laser light could be used for FTS, combining the wavelength coverage of a thermal source with the beam quality of a laser. This is a game changer for implementing FTS over a long path length as required in environmental sensing, but (for reasons of signal-to-noise) is incompatible with a geometry in which the returned light is very weak. Unmanned aerial vehicle (UAV, or drone) technology has now reached a level of maturity that we can conceive of flying a retroreflector on a UAV to provide a highly efficient means of returning the laser light to a ground-based detector. This concept, which we call DRone-Assisted FTS (DRAFTS), immediately offers improved capabilities over the current state-of-the-art including: 1. Acquisition of concentration and flux maps of multiple chemicals, enabled by using broadband mid-infrared light and allowing correlations to be established and causal effects to be inferred.2. Sensing with greater range and in diverse atmospheric conditions, since the UAV-mounted retroreflector eliminates the reliance on airborne particles and offers 10,000 times greater efficiency.3. Deployment in a wider range of scenarios, exploiting the compactness of solid-state lasers, such as using a travelling laser source tracked by the UAV to survey emissions along a road or pipeline.Working with two key partners -- NPL (a leader in fugitive emissions sensing) and Chromacity (a femtosecond laser manufacturer) -- we aim to evaluate DRAFTS and develop it to a level where we can prove its utility in a simulated fugitive emissions field trial. Our partners are contributing £85K toward the project, and span the supply chain from manufacturer to end-user, thus providing critical opportunities for early commercialization of the DRAFTS concept.

该项目是光子学（里德，赫瑞瓦特大学）和机器人学（拉马莫西，爱丁堡大学）研究人员的联合提案，这是一项跨学科合作，为了以一种新的、令人兴奋的方式解决这个问题是必要的。炼油厂、石化厂、碳捕获和储存设施以及垃圾填埋场等设施的甲烷和挥发性碳氢化合物的无组织排放问题每年给能源部门造成高达 50 亿美元的损失。 12% 的温室气体排放并危及工人安全和公共健康，我们的想法是使用中红外激光通过寻找特定化学物质波长的特征吸收来感知碳氢化合物的存在，这种“气体吸收光谱”远非如此。新的，但我们将以与传统方法完全不同的方式来实现它。通常，光学气体检测的工作原理是通过气体传输单波长并寻找强度变化，对于逸散排放传感，这是使用DIAL 技术将强光束照射到空气中，并检测空气中粒子的微弱反向散射（米氏散射），通过寻找两个紧密间隔的波长之间的反向散射强度的微小差异，DIAL 可以感知空气中的粒子。其主要缺点是返回光较弱（毕竟空气是一种非常差的反射体！），并且在任何给定设置中仅对一种化学物质敏感。标准为基于实验室的化学鉴定是傅里叶变换光谱 (FTS)，它使用类似于灯丝灯泡的光源来同时探索大波长范围内的吸收，但遗憾的是，此类热光源的光束质量非常差。 2004 年，Heriot-Watt 证明宽带激光可用于 FTS，将热源的波长覆盖范围与激光的光束质量相结合。用于在环境传感中实现长路径长度上的 FTS 的变换器，但（由于信噪比的原因）与返回光非常弱的无人机（UAV 或无人机）技术不兼容。现在已经达到了成熟的程度，我们可以设想在无人机上安装后向反射器，以提供一种将激光返回地面探测器的高效方法，我们将其称为 DRone 辅助 FTS。（DRAFTS），立即提供了超越当前最先进技术的改进功能，包括： 1. 通过使用宽带中红外光来获取多种化学品的浓度和通量图，并允许建立相关性并确定因果效应2. 由于安装在无人机上的后向反射器消除了对空气中颗粒物的依赖，并且效率提高了 10,000 倍，因此可在更大的范围内和不同的大气条件下进行传感。3.更广泛的场景，利用固态激光器的紧凑性，例如使用无人机跟踪的行进激光源来调查道路或管道沿线的排放。与两个主要合作伙伴合作——NPL（逃逸排放传感领域的领导者） Chromacity（一家飞秒激光器制造商）——我们的目标是评估 DRAFTS 并将其开发到可以在模拟逸散排放现场试验中证明其实用性的水平，我们的合作伙伴将为该项目捐款 8.5 万英镑。跨越从制造商到最终用户的供应链，从而为 DRAFTS 概念的早期商业化提供了关键机会。