Development of a low cost, field portable, Imaging Fourier Transform Interferometer for gas leak detection in the Petrochemical industry

作为英国的主要雇主和出口国，石化业对英国来说非常重要。石化设施覆盖非常大的区域，拥有广泛、复杂的基础设施，可以在高温和高压下运输和储存化学品和气体。工人和附近居民的健康和安全是最重要的，英国石油等公司付出了相当大的努力，并花费了大量资金，以确保他们的石化设施尽可能安全。目前石化设施的健康、安全和污染监测方法包括在石化设施周围部署大量气体探测器作为关键位置。这些气体探测器虽然非常准确，但它们可以检测到气体排放的区域范围有限。除了漏失气体泄漏外，点式探测器不能识别指示应力或约束物质减弱的基础设施中的图案，现有的基于成像的气体监测仪器不能满足石化行业的基本要求。带有过滤器的热像仪和基于过滤器的快照系统都可以检测到大量气体物种的高浓度存在，但灵敏度非常低，无法区分不同物种和复杂气体，并且受到大气中存在的水蒸气的严重影响。成像傅里叶变换干涉仪(FTIR)有可能克服这些其他技术的灵敏度和精度限制，但当前的系统非常昂贵、非常笨重，并且对电源的要求非常高，从而严重影响了便携式和在危险气体泄漏环境中的部署。因此，迫切需要开发一种低成本、高度便携的成像FTIR系统，该系统能够以石化行业所需的灵敏度区分和量化气体物种。拟议的仪器将是中红外傅里叶变换光谱仪的发展，它基于卢瑟福·阿普尔顿实验室(RAL)开发的一种新的静态光学配置。这种仪器被称为微型傅里叶变换光谱仪(MicroFTS)，它使用一种简单的光学装置来分解光，然后将其重新组合，形成复杂的调制干涉图案(称为干涉图)。该仪器结构紧凑(50 mm×50 mm×30 mm)，重量轻(约0.9 kg)，具有很高的数据采集时间速率(~1×10-4 S-1)。该项目的另一个重要组成部分是开发一个易于使用的气体识别和分析软件包，它将使微型FTS数据能够被处理成图像，显示对石化行业最重要的气体物种的存在和浓度。该项目将涉及与国家物理实验室(NPL)的合作。该项目将利用NPL最先进的新分析设施，全面评估新的微型FTS仪器在各种温度(气体和背景)、浓度和混合物下检测对石化行业最重要的气体物种(例如甲烷、一氧化碳、二氧化碳、氨、醋酸)的灵敏度。该项目还将涉及与英国石油公司的广泛合作。将在英国石油公司位于赫尔城附近的Salend工厂开展一系列基于现场的微FTS仪器评估活动。将有机会在正常大气条件下在实际情况下评估仪器的设计和性能，以确保在项目结束时生产的仪器是工业界希望使用的仪器

The Petrochemical Industry is very important to the United Kingdom both as a major employer and exporter. Petrochemicalfacilities extend over very large areas and have extensive, complex infrastructure to transport and store chemicals and gasesunder high temperatures and pressures. The health and saftey of the workers and of nearby residents is of paramountimportance and companies such as BP extend considerable effort and spend very large sums of money to ensure that theirpetrochemical facilities are as safe as possible. The current health & safety and pollution monitoring approaches at Petrochemical facilities involves the deployment of a large number of gas detectors as key locations around the petrochemical facility. These gas detectors while being extremely accurate are limited in the extent of the area that they can detect gas emissions coming from. Apart from missing gas leaks point-based detectors do not have the capability of identification patternson infrastructure indicative of stress or weakening of restraining material.Currently available imaging based gas monitoring instruments are not capable of meeting the essential requirements of thePetrochemical industry. Both Thermal cameras with filters and filter-based snapshot systems can detect the presence of high concentrations of a number of gas species but have very poor sensitivity, they cannot differentiate different species from a complex gas and are severely affected by the presence of water vapour in the atmosphere. Imaging Fourier Transform Interferometers (FTIRs) have the potential to overcome the sensitivity and accuracy limitations of these other technologies but current systems are very expensive, very heavy and have a very high power supply requirement with consequent severe effects on the portability and deployment in environments with hazardous leaking gas. There is therefore an urgent need for the development of a low-cost, highly portable imaging FTIR system that can differentiate and quantify gas species at the sensitivity required by the Petrochemical industry. The proposed instrument will be a development of a mid-infrared Fourier Transform Spectrometer, based on a novel static optical configuration, that has been developed at the Rutherford Appleton Laboratory (RAL). This instrument, known as the micro Fourier Transform Spectrometer (microFTS), employs a simple optical arrangement to split and then recombine light to form a complex modulated interference pattern (known as an interferogram). The instrument is compact (50 mm by 50 mm by 30 mm), lightweight (~0.9 kg) and has a very high data acquisition time rate (~1 x 10-4 s-1). An important, additional component of theproject will be the development of an easy-to-use gas identification and analysis software package which will enable the microFTS data to be processed into images showing both the presence and the concentration of the gas species of most importance to the Petrochemical industry.This project will involve collaboratoration with the National Physical Laboratory (NPL). The project will utilise new, state-of-the-art analytical facilities at NPL which will enable a comprehensive evaluation of the sensitivity of the new microFTS instrument in detecting the gas species of most importance to the Petrochemical industry (e.g. methane, carbon monoxide, carbon dioxide, ammonia, acetic acid), at a range of temperatures (both gas and background), concentrations and mixtures.The project will also involve extensive collaboration with BP. A series of extensive field-based evaluation campaigns of the microFTS instrument will be carried out at the BP facilities at Saltend, near Hull. The opportunity to evaluate the design and capabilities of the instrument in real situations under normal atmospheric conditions will be enbale to ensure that the instrument produced at the end ofproject is an instrument that industry would wish to uti