Biodiesel spectroscopy

G.F. Ghesti, J. Lemos de Macedo, I.S. Resck, J.A. Dias and S.C.L. Dias, ET-Raman spectroscopy quantification of biodiesel in a progressive soybean oil transesterification reaction and its correlation with H NMR spectroscopy methods, Energ. Fuel, 21, 2475-2480 (2007). 

Environmental issues are a current topic that strongly motivates many students and that gets much attention in the news. Several new experiments were devoted to environmental topics. We have already mentioned a laser lab devoted to the study of the kinetics of ozone formation (26). Other new experiments studied the thermochemistry of biodiesel (135), the use of spectroscopy to estimate the average temperature of the earth s atmosphere... 

Chemical analyses of biodiesel may be accomplished through standard methods as recommended by ASTM and other organizations, but these measures do not determine all aspects of biodiesel chemistry (20, 21). Knothe (21) extensively described methods of measuring frawi-esterification progress and assuring biodiesel quality, and suggested that no single test could assure quality. Online methods, such as NIR (near infrared spectroscopy), could be used to rapidly screen products to... 

Several spectroscopic methods have been used to monitor the levels of heavy metals in man, fossil fuels and environment. They include flame atomic absorption spectrometry (AAS), atomic emission spectroscopy (AES), graphite furnace atomic absorption sp>ectrometry (GFAAS), inductively coupled plasma-atomic emission sp>ectroscopy (ICP/AES), inductively coupled plasma mass spectrometry (ICP/MS), x-ray fluorescence sp>ectroscopy (XRFS), isotope dilution mass spectrometry (IDMS), electrothermal atomic absorption spectrometry (ETAAS) e.t.c. Also other spectroscopic methods have been used for analysis of the quality composition of the alternative fuels such as biodiesel. These include Nuclear magnetic resonance spectroscopy (NMR), Near infrared spectroscopy (NIR), inductively coupled plasma optical emission spectrometry (ICP-OES) e.t.c. 

In Experiment 27A, coconut oil is converted into biodiesel, and other oils are converted into biodiesel in Experiment 27B. In Experiment 27C, the biodiesel is analyzed by infrared spectroscopy, NMR spectroscopy, and gas chromatography-mass spectrometry (GC-MS). The heat of combustion of biodiesel can also be determined in Experiment 27C. 

Spectroscopy. Obtain an infrared spectrum using salt plates (see Technique 25, Section 25.2). Determine the proton NMR spectrum using 3-4 drops of your biodiesel in 0.7 mL of deuterated chloroform. Since biodiesel consists of a mixture of different molecules, it is not helpful to perform an integration of the area imder the peaks. Compare the NMR spectrum of biodiesel to the spectrum of vegetable oil shown here. Finally, analyze your sample using gas chromatography-mass spectrometry (GC-MS). Your instructor will provide you with instructions on how to do this. 

Morgenstem M, Cline J, Meyer S, Cataldo S. Determination of the kinetics of biodiesel production using proton nuclear magnetic resonance spectroscopy ( H-NMR). Energy Fuels 2006 20 1350-1353. 

D73 71 Biodiesel (FAME) content in diesel fuel by mid infrared spectroscopy EN 14105 Free and total glycerol, acylglycerols by CC... 

Zhang, W.-B., 2012. Review on analysis of biodiesel with infrared spectroscopy. Renew. Sustainable Energy Rev. 16 (8), 6048-6058. 

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