When I hear biofuels and biodiesel, I think attempts to save the planet from political and environmental problems that can be catastrophic. Testing biofuels is done to ensure the products are of high quality, safe, and will not damage engines. Attached are four application notes for analysis of biodiesel using gas chromatography. GC is not the only necessary tool in testing biofuels. Ion chromatography, FTIR, UV, and ICP are also used. Below you will find relevant application notes for all of these techniques.
The GC application notes with complete consumable information are
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Determination of Free and Total Glycerin in B-100 Biodiesel via Method ASTM D6584. Free and bonded glycerin content of the finished biodiesel product indicates the quality of the product. A high glycerin content may cause problems in a fuel system that can lead to injector clogging and formation of deposits in injector nozzles, pistons, and valves. The American Society for Testing and Materials (ASTM) has designated certain standards for the amount of free and total glycerin content in a finished biodiesel B100 product. Through this method, the analyst can determine the amount of free and total glycerin in the range of 0.005 to 0.05 mass % and 0.05 to 0.5 mass %, respectively. Analyzing the amount of free and total glycerin in the form of mono-, di- or triglycerides during the esterification process is mandatory when manufacturing biodiesel. ASTM has determined a cutoff value of 0.240% by mass as the amount of total glycerin that can be present in B100. ASTM D 6584 specifies the use of a gas chromatograph (GC) equipped with a cold on-column injector and an FID detector. In this application, we demonstrate the use of the Thermo Scientific TRACE GC Ultra™ and a PTV injector in simulated on-column mode to obtain rapid and accurate results when using the ASTM specifications. Download application note here, Total Glycerin in B-100 by ASTM D6584
- Determination of Total FAME and Linolenic Acid Methyl Ester in Pure Biodiesel (B100) by GC in Compliance with EN 14103. This application note relates to the determination of total FAME and linolenic acid methyl ester in biodiesel according to EN 14103. The cetane number of biodiesel, designation of combustion quality, depends on the distribution of fatty acids in the original oil. Thus a reliable characterization of FAME is essential for a more accurate calculation of the cetane index. EN 14103 is a standard method for determination of esters and linolenic acid methyl ester and can be applied to biodiesel analysis. EN 14103 requires GC analysis with a split/splitless (SSL) or a programmable temperature vaporizing (PTV) injector and a wax column for a detailed separation of FAMEs. This GC analysis provides verification that the esters content in B100 biodiesel is greater than 96.5% m/m and the linolenic acid methyl ester content is lower than 12% m/m, in accordance with the specifications reported in EN 14214:2003, while also allowing the characterization of FAME composition. Calculation of the percentage of FAME is achieved with internal standard calibration. This method is suitable for FAMEs which contain methyl esters between C14 and C24. Download application note here, Total FAME and Linolenic Acid Methyl Ester in B-100 by EN 14103
- Determination of Free and Total Glycerin in Pure Biodiesel (B100) by GC in Compliance with EN 14105. Free and bonded glycerin content is an indicator of the biodiesel quality. Low levels of total glycerin ensure high conversion of the oil, while high levels of glycerin and glycerides can cause injector deposits, clogged fuelling systems, and poor cold weather operation. The determination of glycerin levels provides verification that the free glycerin, mono-glycerides, di-glycerides, tri-glycerides, and total glycerin contents in B100 are lower than the limits shown in Table 1, in accordance with the specifications reported in EN 14214:2003. Download application note here, Free and Total Glycerin in B-100 by EN 14105
- Determination of Methanol Content in Pure Biodiesel (B100) by Headspace-GC in Compliance with EN 14110. This application note relates to the determination of methanol in biodiesel according to EN 14110. Monitoring residual methanol in B100 is a matter of safety since even small amounts of this material can reduce the flash point of the biodiesel. Moreover, residual methanol can affect fuel pumps, seals and elastomers and can result in poor combustion properties. EN 14110 requires a headspace GC method, based on either polar or non-polar columns, and is applicable for a concentration range from 0.01% m/m to 0.5% m/m of methanol (MeOH). The method is not applicable to mixtures of FAME that contain other low boiling components, although the use of the Thermo Scientific TRACE™ TR-BIODIESEL column allows for good separation of methanol from most of these volatiles, producing reliable results. EN 14214:2003 standard specifications require the methanol content to be < 0.2% m/m. Download application note here, Methanol Content in B-100 by EN 14110
There are a few other techniques needed in a lab for more complete characterization of biofuels. Staying with the chromatography techniques here are a few using ion chromatography.
- Assay of Fuel-Grade Butanol for Total and Potential Sulfate and Total Chloride Per ASTM D7328-07.Download application note here, ASTM D7328-07
- Determination of Total and Potential Sulfate and Total Chloride in Fuel-Grade Butanol Per ASTM D7319-09, download application note here, ASTM D7319-09
Below are links to other applications using other techniques that further complete the analysis of biodiesel and biofuels.
- Determination of Sulfur in ULSD, Biodiesel and Jet Fuel using a Thermo Scientific iPRO 5000 Series Analyzer According to ASTM D5453. Application note, https://fscimage.thermoscientific.com/images/D20133~.pdf
- Biodiesel (FAME) Analysis by FT-IR. Application note, https://fscimage.thermoscientific.com/images/D10291~.pdf
- Petrochemical Series – Analysis of Biodiesel using the iCAP 6000 series ICP. Application note, https://fscimage.thermoscientific.com/images/D10231~.pdf
- Determination of Free Glycerol in Biodiesel with the Evolution Array UV-Visible Spectrophotometer. Application note, https://fscimage.thermoscientific.com/images/D10977~.pdf
- Trace Contaminant Analysis in Biodiesel with an Antaris II FT-NIR Analyzer. Application note, https://fscimage.thermoscientific.com/images/D14201~.pdf
- SOLA II — Trace Sulfur Analysis in the Production of Biofuels. Application note, https://fscimage.thermoscientific.com/images/D10356~.pdf