Real-time detection of naphtha using photothermal cantilever deflection spectroscopy

石脑油是一种稀释剂，用于从油砂中加工沥青，由低分子量脂肪族和芳香族烃组成。其它石脑油组分包括异链烷烃和环烷烃。在油砂加工过程中，几乎所有的石脑油都被回收。 然而，在优化的加工条件下，小于1%的石脑油损失到尾矿流中是不可避免的。目前，石脑油的监测是通过每隔6小时手动收集样品并运送到实验室通过GC-质谱仪进行分析来进行的，这是庞大的、昂贵的并且需要训练有素的人员。任何可能泄漏到尾渣流中的石脑油都不会被检测到，直到下一次预定的手动测试。本提案的目的是设计和开发一种微型、高灵敏度的传感器，能够实时检测尾矿流和尾矿池中的石脑油。石脑油是碳氢化合物的混合物;基于界面化学的传感方法将遭受误报。在这里，我们提出了一种新的传感器，可以提供“分子指纹”的石脑油在真实的时间。 该技术结合了微悬臂梁作为物理（位移）传感器的灵敏度与中红外光谱的选择性。中红外区通常被称为“分子指纹区”，具有独特的振动峰，没有泛音。这种方法克服了悬臂梁化学传感平台的缺点（缺乏选择性）以及传统的中红外光谱，包括缺乏灵敏度，体积庞大，和成本的考虑。所提出的设备将是微型的，高度敏感的，非常有选择性的，和廉价的。此外，该技术适合于大规模生产和大规模部署，这使得其对于工业实施非常可行。

Naphtha, a diluent, used in processing bitumen from oil sands, consists of low molecular weight aliphatic and aromatics hydrocarbons. Other naphtha constituents include iso-paraffins and naphathenes. During oil sands processing, almost all the naphtha is recovered. However, under optimized processing conditions less than 1% naphtha loss to the tailings stream is inevitable. At present naphtha is monitored by manually collecting samples at 6 hr intervals and transported to a lab for analysis by GC-mass spectrometer, which is bulky, expensive and requires trained personal. Any possible leak of naphtha to the tailings stream will go undetected until the next scheduled manual test. The objective of this proposal is to design and develop a miniature, highly sensitive sensor capable of real-time detection of naphtha in the tailings stream and tailings pond. Naptha is a mixture of hydrocarbons; sensing approaches based on interfacial chemistry will suffer from false positives. Here we propose a novel sensor that can provide "molecular fingerprints" of naphtha in real time. The proposed technique combines the sensitivity of a micro cantilever as a physical (displacement) sensor with the selectivity of mid infrared spectroscopy. Mid infrared region is often called "molecular finger print regime" has unique vibrational peaks that is free from overtones. This approach overcomes the disadvantages of cantilever chemical sensing platform (lack of selectivity) as well as of the conventional mid infrared spectroscopy which includes the lack of sensitivity, bulky, and cost considerations. The proposed device will be miniature, highly sensitive, very selective, and inexpensive. Furthermore, this technique is amenable for mass production and mass deployment which makes it excellently feasible for industrial implementations.