Development of a low cost, field portable 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过程和应用的关键组成部分。获取具有基本的空间和时间分辨率和检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，也是一项关键的市场需求。各种各样的研究人员、利益集团、商业和监管机构需要在从点源到景观尺度的空间尺度上对碳氢化合物气体（甲烷、丙烷、丁烷和乙烷）进行检测、定量和区分。识别甲烷的来源和进入大气的通量是气候变化研究的一个关键组成部分。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空间和时间可变性，例如北方泥炭地的融化，加上受影响地区的面积非常大。散逸性甲烷排放也引起了广泛的商业和监管组织的极大兴趣。垃圾填埋场的气体排放是议会和环境署面临的常见环境问题，而管道的无组织排放对于从家庭供应到大型石油化工设施的许多商业组织来说是一个非常昂贵和不便的问题。陆上微渗漏的检测是勘探碳氢化合物地球科学家的一个关键目标，因为它们高度指示富碳氢化合物盆地的存在。微渗漏的特征是排放生热衍生的烃类气体，其通常含有显著浓度的乙烷、丙烷、丁烷和冷凝物。热成因天然气地球化学不同于几乎完全由甲烷组成的生物成因天然气，为微渗漏识别提供了直接、远程的方法。这种检测能力也可用于量化非常规天然气矿床（页岩气和煤层气）开采对环境的影响。对井场挥发性生热烃气体排放的体积、成分和持续时间了解甚少。对整个井场的碳氢化合物排放进行连续、完整、准确的测量，可以为环境影响的讨论提供信息，并影响未来开发的决策。所有这些应用都需要在从现场到景观的范围内长时间（昼夜）获得准确、连续的碳氢化合物气体排放测量值。目前用于检测烃类气体排放的基于场的方法不能满足研究人员和用户的要求，因为它们耗时，基于遥感的方法提供了一种潜在的解决方案，但目前的技术要么不准确，（例如反射光谱）或非常昂贵且不切实际目前可用的基于成像的气体监测仪器不能以足够的精度分辨烃气体。成像傅里叶变换干涉仪（FTIRs）具有检测和量化碳氢化合物排放的潜力，但是目前的成像FTIRs的设计使得它们对于环境科学家的操作部署来说过于昂贵和笨重，迫切需要开发低成本、高度便携、高度灵敏的成像系统。该项目的目的是进行一项实验室研究，以开发和验证一种低成本、轻便、紧凑的成像傅里叶变换红外光谱仪，该光谱仪具有足够的光谱分辨率和辐射灵敏度，可检测、量化和区分生物成因和热成因烃类气体。

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.