Matoug Mohamed M, Gordon Reuven
Department of Electrical and Computer Engineering, University of Victoria, P.O. Box 1700, STN CSC, Victoria B.C. V8W 2Y2, Canada.
ACS Omega. 2018 Mar 21;3(3):3406-3412. doi: 10.1021/acsomega.8b00017. eCollection 2018 Mar 31.
Terahertz time-domain spectroscopy (THz-TDS) was used to study the asphaltenes in different crude oils. THz-TDS has a feature of measuring the amplitude and time delay and consequently the refractive index and absorption coefficient spectra simultaneously. Our approach was based on measuring the THz signal from neat crude oil samples and comparing it with the THz signal after removing the asphaltene from the oil samples (maltene). The results show that the differences in the time delay and the peak amplitude between the neat oil and the maltene have a linear relation with the asphaltene content. The refractive index spectra of the asphaltene show variation in the low THz frequencies and comparable spectra in the higher frequencies. The absorption of the asphaltene was mild, and no distinctive absorption feature was observed except for some narrow absorption peaks that we attributed to water molecules adsorbed on the asphaltene.
太赫兹时域光谱（THz-TDS）被用于研究不同原油中的沥青质。太赫兹时域光谱具有同时测量振幅和时间延迟，进而同时测量折射率和吸收系数光谱的特点。我们的方法基于测量纯原油样品的太赫兹信号，并将其与从油样中去除沥青质（软沥青质）后的太赫兹信号进行比较。结果表明，纯油和软沥青质之间的时间延迟和峰值振幅差异与沥青质含量呈线性关系。沥青质的折射率光谱在低太赫兹频率下表现出变化，而在较高频率下光谱具有可比性。沥青质的吸收较弱，除了一些我们归因于吸附在沥青质上的水分子的窄吸收峰外，未观察到明显的吸收特征。
