Hilaire F, Basset E, Bayard R, Gallardo M, Thiebaut D, Vial J
UMR CBI, Laboratoire des Sciences Analytiques, Bioanalytiques et Miniaturisation, ESPCI Paris, PSL Research University, 10 rue Vauquelin, 75231 Paris Cedex 05, France.
ENGIE, Research and Technologies Division, CRIGEN, 361 av. du Président Wilson, BP 33, 93211 St-Denis-la-Plaine Cedex, France.
J Chromatogr A. 2017 Nov 17;1524:222-232. doi: 10.1016/j.chroma.2017.09.071. Epub 2017 Sep 29.
The gas industry is going to be revolutionized by being able to generate bioenergy from biomass. The production of biomethane - a green substitute of natural gas - is growing in Europe and the United-States of America. Biomethane can be injected into the gas grid or used as fuel for vehicles after compression. Due to various biomass inputs (e.g. agricultural wastes, sludges from sewage treatment plants, etc.), production processes (e.g. anaerobic digestion, municipal solid waste (MSW) landfills), seasonal effects and purification processes (e.g. gas scrubbers, pressure swing adsorption, membranes for biogas upgrading), the composition and quality of biogas and biomethane produced is difficult to assess. All previous publications dealing with biogas analysis reported that hundreds of chemicals from ten chemical families do exist in trace amounts in biogas. However, to the best of our knowledge, no study reported a detailed analysis or the implementation of comprehensive two-dimensional gas chromatography (GC×GC) for biogas matrices. This is the reason why the benefit of implementing two-dimensional gas chromatography for the characterization of biogas and biomethane samples was evaluated. In a first step, a standard mixture of 89 compounds belonging to 10 chemical families, representative of those likely to be found, was used to optimize the analytical method. A set consisting of a non-polar and a polar columns, respectively in the first and the second dimension, was used with a modulation period of six seconds. Applied to ten samples of raw biogas, treated biogas and biomethane collected on 4 industrial sites (two MSW landfills, one anaerobic digester on a wastewater treatment plant and one agricultural biogas plant), this analytical method provided a "fingerprint" of the gases composition at the molecular level in all biogas and biomethane samples. Estimated limits of detection (far below the μgNm) coupled with the resolution of GC×GC allowed the comparison of the real samples considered. This first implementation of GC×GC for the analysis of biogas and biomethane demonstrated unambiguously that it is a promising tool to provide a "fingerprint" of samples, and to monitor trace compounds by families.
通过利用生物质来生产生物能源，天然气行业将发生变革。生物甲烷（天然气的绿色替代品）的产量在欧洲和美国都在不断增长。生物甲烷经压缩后可注入燃气网络或用作车辆燃料。由于生物质的输入种类繁多（如农业废弃物、污水处理厂的污泥等）、生产工艺多样（如厌氧消化、城市固体废弃物填埋）、存在季节性影响以及净化工艺不同（如气体洗涤器、变压吸附、用于沼气提纯的膜），所产生的沼气和生物甲烷的成分及质量难以评估。以往所有关于沼气分析的出版物都报道，沼气中确实存在来自十个化学族的数百种痕量化学物质。然而，据我们所知，尚无研究报道对沼气基质进行详细分析或采用全面二维气相色谱法（GC×GC）。这就是评估采用二维气相色谱法对沼气和生物甲烷样品进行表征的益处的原因。第一步，使用了一种由属于十个化学族的89种化合物组成的标准混合物，这些化合物代表了可能存在的物质，用于优化分析方法。采用分别在第一维和第二维使用一根非极性柱和一根极性柱的组合，调制周期为6秒。将这种分析方法应用于在4个工业场所收集的10个原始沼气、处理后沼气和生物甲烷样品（两个城市固体废弃物填埋场、一个污水处理厂的厌氧消化器以及一个农业沼气厂），该方法在分子水平上提供了所有沼气和生物甲烷样品气体成分的“指纹图谱”。估计的检测限（远低于μg/Nm³）加上GC×GC的分辨率使得能够对所考虑的实际样品进行比较。GC×GC首次用于沼气和生物甲烷分析明确表明，它是一种很有前景的工具，可提供样品 “指纹图谱” 并按族监测痕量化合物。
