Fast two‐dimensional gas chromatography applied in the characterization of bio‐oil from the pyrolysis of coconut fibers

Abstract

The goal of this paper is the evaluation of fast two‐dimensional gas chromatography applied to bio‐oil samples. Bio‐oils are complex matrixes that usually are analyzed by conventional gas chromatography, involving long columns, long time of analysis due to slow heating rates, and consequently, high cost associated to time consumed. Fast gas chromatography techniques are based on the use of narrow capillary columns that allow the achievement high‐speed separations for complex samples, maintaining excellent resolution. Firstly, the two‐dimensional gas chromatography method was optimized varying the heating rate (10, 15 and 20°C min−1) and achieving the optimal separation at 15°C min−1. This method allies a good separation of bio‐oil constituents with shorter time analysis. The developed method and the traditional conventional two‐dimensional gas chromatography method (used in previous studies) were applied in the analysis of a mixture of 30 standard compounds. Despite coelutions of short retention time peaks (compounds with very similar physical‐chemical properties), the fast two‐dimensional gas chromatography method showed an increase in chromatographic signal and a noise reduction. Good results were also obtained in the real bio‐oil sample. Fast two‐dimensional gas chromatography maintained all the chromatographic information from conventional two‐dimensional gas chromatography, reducing drastically the total time of analysis.

Two-Dimensional Gas Chromatography Characterization of Pyrolysis Bio-oils: A Review

“…Typical primary column dimensions in the normal-phase configuration were 30–60 m × 0.25 mm × 0.25–0.50 μm; see Table . In some cases, only 10 m long with an internal diameter of 0.18 mm thick columns were applied as primary columns for fast GC × GC applications. − The typical stationary phases of primary columns were nonpolar phases such as 100% poly­(dimethylsiloxane) (PDMS), 5% phenyl–95% PDMS, or their equivalents. Characteristic parameters of secondary columns were 1–2.15 m × 0.10–0.25 mm × 0.10–0.50 μm.…”

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“…The information about the impact of the detector scanning rate on qualitative and quantitative data is presented in Section . Schena et al studied the influence of primary oven temperature ramp rate on the separation. Optimal separation of a bio-oil sample was achieved at a temperature ramp rate of 15 °C/min, which allowed a faster analysis (∼20 min) when compared to conventional heating rates (∼3 min) used in the GC × GC studies of the bio-oils .…”

“…Schena et al studied the influence of primary oven temperature ramp rate on the separation. Optimal separation of a bio-oil sample was achieved at a temperature ramp rate of 15 °C/min, which allowed a faster analysis (∼20 min) when compared to conventional heating rates (∼3 min) used in the GC × GC studies of the bio-oils . However, it must be pointed out that such fast GC × GC would likely be suitable just for some specific less complex bio-oil samples.…”

Advanced mono‐ and multi‐dimensional gas chromatography–mass spectrometry techniques for oxygen‐containing compound characterization in biomass and biofuel samples

“…The authors claimed that comprehensive 2D‐GC‐MS could allow enhanced diagnostics for process performances or risk management in the current contest of the new gas and bioenergy industry [65]. In the past 5 years, GC×GC‐MS methodology has been widely employed for the characterization FAMEs, phenols and ketones and other oxygenated compounds in bio‐oil from the pyrolysis of different biomass feedstock, such as coffee waste, [66,67], coconut fibers [68], rice straw [69,70], tropical seeds [71], residue of vegetable oil [72], as well as in the characterization of creosote from wood coal tars [73], and the hydrogenation products of bio‐crude obtained from hydrothermally liquefied algal biomass [74].…”