Recent Advances in the Characterization of Gaseous and Liquid Fuels by Vibrational Spectroscopy

Abstract

Most commercial gaseous and liquid fuels are mixtures of multiple chemical compounds. In recent years, these mixtures became even more complicated when the suppliers started to admix biofuels into the petrochemical basic fuels. As the properties of such mixtures can vary with composition, there is a need for reliable analytical technologies in order to ensure stable operation of devices such as internal combustion engines and gas turbines. Vibrational spectroscopic methods have proved their suitability for fuel characterization. Moreover, they have the potential to overcome existing limitations of established technologies, because they are fast and accurate, and they do not require sampling; hence they can be deployed as inline sensors. This article reviews the recent advances of vibrational spectroscopy in terms of infrared absorption (IR) and Raman spectroscopy in the context of fuel characterization. The focus of the paper lies on gaseous and liquid fuels, which are dominant in the transportation sector and in the distributed generation of power. On top of an introduction to the physical principles and review of the literature, the techniques are critically discussed and compared with each other.

A prototype of an optical sensor for the identification of diesel oil adulterated by kerosene

“…Liquid fuel adulteration, for example, mixing of diesel oil by kerosene has several far-reaching impacts such as environmental pollution. Optical spectroscopy is a useful tool for testing the quality of liquid fuels, and typically it is based on spectral fingerprints identification of organic molecules in the infrared spectral range [1,2]. Usually, one can measure either transmission or reflection spectrum from liquid samples.…”

Optics and Spectroscopy for Fluid Characterization

“…The large number of review articles that are frequently published in these areas is evidence of this. Recent examples have focused on applications of optical diagnostics to gas phase environments [1][2][3][4][5], liquids [1,4,6,7], and multiphase systems [7][8][9][10]. A key feature of such light-based methods is that they are usually non-intrusive, and hence they do not notably affect the system under investigation.…”

Nanofotónica en el análisis de biocombustibles

“…Con este artículo queda en evidencia que una herramienta nanofotónica puede ser una solución complementaria al reto global para la determinación del contenido porcentual de biodiésel en diésel. Es aquí donde las técnicas basadas en la interacción de la luz con la materia son de gran utilidad [7][8][9][10][11].…”

“…La utilidad de esta técnica se debe principalmente a su sensibilidad para dar información sobre la identidad química o molecular [17][18][19], estados de carga [7,12], procesos en interfaces, orden estructural [7,[12][13][14][15][16][17][18][19][20]. Es por esto que la espectroscopia Raman proyecta un gran mercado para aplicaciones de análisis en medicina/ nanomedicina [18], tecnología de alimentos [20], industria química y petroquímica [20], industria de materiales [16,21], biocombustibles [7,9,22,23]. Pese al gran potencial, actualmente hay una necesidad de concebir sistemas de análisis Raman de fácil uso, económicos y portátiles [17].…”