Fuel Property Determination of Biodiesel-Diesel Blends By Terahertz Spectrum

Abstract

The frequency-dependent absorption characteristics of biodiesel and its blends with conventional diesel fuel have been researched in the spectral range of 0.2-1.5 THz by the terahertz time-domain spectroscopy (THz-TDS). The absorption coefficient presented a regular increasing with biodiesel content. A nonlinear multivariate model that correlating cetane number and solidifying point of bio-diesel blends with absorption coefficient has been established, making the quantitative analysis of fuel properties simple. The results made the cetane number and solidifying point prediction possible by THz-TDS technology and indicated a bright future in practical application.

Industrial Applications of Terahertz Sensing: State of Play

“…As in crude oil, THz TDS was applied to identifying fuel grades, additives, and contaminants. A particularly important aspect of fuel analysis is the ability to distinguish and quantify its octane number [147,148,149,150,151,152,153]. This has been demonstrated in several studies: in gasoline and diesel [147], in mixtures of gasoline and diesel [148], in mixtures of 90# and 97# octane gasoline (Figure 21) [149,150], in gasoline of 87#, 89#, and 90# octane [151], and in derv fuel oils [152].…”

“…Likewise, it is highly useful to identify and quantify the common additives that are used to augment fuel and to improve its performance [151,153,154]. Evaluation of the cetane number was demonstrated in biodiesel-diesel blends [153], and in ethanol-gasoline mixtures the content of ethanol was determined with 1% accuracy [154,155]. Ethanol being a polar liquid, its addition strongly increases both the refractive index and the absorption coefficient of the mixture compared with those of pure gasoline.…”

Increasing the resolution of the reconstructed image in terahertz pulse time-domain holography

“…Although it can be time consuming, point-by-point object scanning with the focused THz TDS beam allows for spectrally resolved THz imaging. This approach, first demonstrated in 1996 4,5 , has been successfully applied to numerous applications, including: (i) in vitro and in vivo tissue characterization on the cellular level for ophtalmology 6 , dentistry 7,8 and cancerous cell detection 9–13 ; (ii) non-contact monitoring of parcels and luggage contents for concealed metals or chemical/biological threats 14–17 ; (iii) quality control and identification of harmful substances in food products 18–20 ; (iv) defect testing in materials 21–25 ; (v) chemical composition analysis for oils and fuels 26–28 ; and (vi) non-destructive composition analysis of high-value art objects and antiquities 29–32 . All of these examples involve point-by-point scanning with THz TDS setups, and would greatly benefit from immediate detection of transverse complex amplitude spatio-temporal distribution in the wavefront cross-section.…”

Characterization of Inclusions in Evolution of Sodium Sulfate Using Terahertz Time-domain Spectroscopy

“…11 In recent decades, because of these unique properties, THz-TDS has attracted more attention and has been employed in various fields, such as biochemistry, safety, medicine quality control, food, petroleum and geological evolution. [12][13][14][15][16] In this paper, THz-TDS was applied to measure sodium sulfate crystals with different growth temperatures. The change of fluid inclusion and its influence on the evolution of sodium sulfate were characterized by terahertz optical parameters, which was verified by XRD and polarizing microscopy.…”