Development of a low cost, lightweight imaging FTIR to detect and differentiate between biogenically and thermogenically derived hydrocarbon gas.

甲烷气体排放的检测和量化是广泛的环境科学进程和应用的关键组成部分。获取具有基本空间和时间分辨率和探测灵敏度的采样数据集，以满足关键科学问题、气候模型和商业用户的要求，是一项重大的环境挑战，并构成关键的市场需求。不同的研究人员、利益集团、商业和监管组织要求在从点源到景观尺度的空间尺度上检测、量化和区分碳氢气体(甲烷、丙烷、丁烷和乙烷)。识别甲烷的来源和进入大气的通量是气候变化研究的关键组成部分。准确量化甲烷贡献的一个重大挑战是许多环境过程的甲烷排放的时空变异性，例如北部泥炭地融化，再加上受影响地区的面积特别大。大量的商业和监管组织也对甲烷的逸散排放非常感兴趣。垃圾填埋场的气体排放是议会和环保局面临的共同环境问题，而管道泄漏对从国内供应到大型石化设施的许多商业组织来说是一个非常昂贵和不便的问题。探测到陆上微渗漏是碳氢化合物地球科学家勘探的关键目标，因为它们高度指示着富含碳氢化合物的盆地的存在。微渗漏的特征是排放热源衍生的碳氢化合物气体，通常含有大量的乙烷、丙烷、丁烷和凝析油。热成因气体地球化学不同于生物成因气体，后者几乎完全由甲烷组成，这为微渗漏的识别提供了一种直接的、远程的方法。这种探测能力还可以用来量化开采非常规天然气矿藏(页岩气和煤层气)对环境的影响。从井场排放的逃逸热源碳氢化合物气体的数量、组成和持续时间知之甚少。连续、完整、准确地测量整个井场的碳氢化合物排放量可以为环境影响的讨论提供信息，并影响对未来开发的决策。所有这些应用都需要获得从场地到景观的范围内长时间(夜间和白天)烃类气体排放的准确、连续的测量。基于遥感的方法提供了一种潜在的解决方案，但现有的方法要么不准确(如反射光谱)，要么昂贵且不切实际(如LiDAR)。现有的基于成像的气体监测仪器不能对烃类气体进行足够准确的解析。成像傅里叶变换干涉仪(FTIR)具有探测和量化碳氢化合物排放的潜力，但目前成像FTIR的设计使得它们昂贵得令人望而却步，并且对于环境科学家的操作部署来说是繁琐的。该项目的目的是开展一项实验室研究，以开发和验证一种低成本、轻巧、紧凑的傅里叶变换红外光谱仪，具有足够的光谱分辨率和辐射灵敏度，以探测、量化和区分生物来源和热源来源的碳氢化合物气体。

The detection and quantification of methane gas emissions is a critical component of a wide range of environmental science processes and applications. Acquisition of sampling datasets with the essential spatial and temporal resolution and detection sensitivity to address the requirements of the key science questions, climate models and commercial users is a significant environmental challenge and poses a critical market need. A diverse range of researchers, interest groups, commercial and regulatory organisations require the detection, quantification and differentiation of hydrocarbon gases (methane, propane, butane, & ethane) at spatial scales ranging from point source to landscape scale.Identification of the sources and fluxes of methane into the atmosphere is a critical component of climate change research. A significant challenge to accurately quantifying the methane contribution is the spatial and temporal variability in methane emissions of many of the environmental processes, e.g. melting of boreal peatland, combined with the exceptionally large size of the affected areas. Fugative methane emissions are also of critical interest to a wide range of commercial and regulatory organisations. Gas emissions from landfill sites are a common environmental issue faced by councils and the environment agency while fugitive emissions from pipelines are a very expensive and inconvenient problem for many commercial organisations ranging from domestic supply to large-scale petro-chemical facilities.Detection of on-shore microseeps is a key objective of exploration hydrocarbon geoscientists as they are highly indicative of the presence of a hydrocarbon-rich basin. Microseeps are characterised by the emission of thermogenically derived hydrocarbon gas which usually contains significant concentrations of ethane, propane, butanes and condensate. Thermogenic gas geochemistry differs from biogenic gas, which consists almost entirely of methane, providing a direct, remote methodology for microseep identification. This detection capability could also be utilised to quantify the environmental impact of the exploitation of unconventional gas deposits (shale gas & coalbed methane). The volume, composition and duration of fugitive thermogenic hydrocarbon gas emissions from well sites is poorly understood. Continuous, complete, accurate measurements of hydrocarbon emissions over the entire well site could inform discussion of the environmental impact and influence decisions on future developments. All these applications require the acquisition of accurate, continuous measurements of hydrocarbon gas emissions over prolonged periods (night and day) over scales ranging from site to landscape. Current field-based methods for detecting hydrocarbon gas emissions cannot meet the requirements of researchers and users as they are time-consuming, costly and produce very sparse spatial datasets Remote-sensing based methods offer a potential solution however current techniques are either inaccurate (e.g. reflectance spectroscopy) or very costly and impractical (e.g. LiDAR).Currently available imaging based gas monitoring instruments are not capable of resolving the hydrocarbon gases with sufficient accuracy. Imaging Fourier Transform Interferometers (FTIRs) have the potential to detect and quantify hydrocarbon emissions but the current design of imaging FTIRs make them prohibitively expensive and cumbersome for operational deployment by environmental scientists.There is an urgent need for the development of a low-cost, highly portable, highly sensitive imaging system. The aim of this project is to undertake a laboratory-based study to develop, and validate a low cost, lightweight, compact imaging Fourier Transform InfraRed (FTIR) spectrometer with sufficient spectral resolution and radiometric sensitivity to detect, quantify and differentiate between biogenically and thermogenically derived hydrocarbon gas.