Department of Thematic Studies - Environmental Change, Linköping University, Linköping 581 83, Sweden.
Tekniska Verken AB, Linköping 581 15, Sweden.
Environ Sci Technol. 2024 Feb 27;58(8):3766-3775. doi: 10.1021/acs.est.3c06810. Epub 2024 Feb 14.
Open storages of organic material represent potentially large sources of the greenhouse gas methane (CH), an emissions source that will likely become more common as a part of societal efforts toward sustainability. Hence, monitoring and minimizing CH emissions from such facilities are key, but effective assessment of emissions without disturbing the flux is challenging. We demonstrate the capacity of using a novel high-resolution hyperspectral camera to perform sensitive CH flux assessments at such facilities, using as a test case a biofertilizer storage tank for residual material from a biogas plant. The camera and simultaneous conventional flux chamber measurements showed emissions of 6.0 ± 1.3 and 13 ± 5.7 kg of CH h, respectively. The camera measurements covered the whole tank surface of 1104 m, and the chamber results were extrapolated from measurements over 5 m. This corresponds to 0.7-1.4% of the total CH production at the biogas plant (1330 N m h corresponding to 950 kg h). The camera could assess the entire tank emission in minutes without disturbing normal operations at the plant and revealed additional unknown emissions from the inlet to the tank (17 g of CH h) and during the loading of the biofertilizer into trucks (3.1 kg of CH h during loading events). This study illustrates the importance of adequate measurement capacity to map methane fluxes and to verify that methane emission mitigation efforts are effective. Given the high methane emissions observed, it is important to reduce methane emissions from open storage of organic material, for example by improved digestion in the biogas reactor, precooling of sludge before storage, or building gastight storage tanks with sealed covers. We conclude that hyperspectral, ground-based remote sensing is a promising approach for greenhouse gas monitoring and mitigation.
有机物质的开放式储存是甲烷（CH）这种温室气体的潜在重要来源，随着社会向可持续发展努力，这种排放源可能会变得更加普遍。因此，监测和尽量减少这些设施的 CH 排放是关键，但在不干扰通量的情况下进行有效的排放评估是具有挑战性的。我们展示了使用新型高分辨率高光谱相机在这些设施中进行敏感 CH 通量评估的能力，以沼气厂剩余物料的生物肥料储存罐为例。相机和同时进行的常规通量室测量分别显示出 6.0 ± 1.3 和 13 ± 5.7 kg CH h 的排放量。相机测量覆盖了 1104 m 的整个罐体表面，而腔室结果是从 5 m 以上的测量中推断出来的。这相当于沼气厂总 CH 产量的 0.7-1.4%（对应 950 kg h 的 1330 N m h）。相机可以在不干扰工厂正常运行的情况下，在几分钟内评估整个罐体的排放情况，并揭示从罐体入口到罐体（17 g CH h）和在生物肥料装入卡车期间（装载过程中 3.1 kg CH h）的未知排放。本研究说明了具有适当测量能力以绘制甲烷通量图并验证甲烷减排努力是否有效的重要性。鉴于观察到的高甲烷排放量，减少有机物质开放式储存的甲烷排放非常重要，例如通过在沼气反应器中进行更好的消化、在储存前对污泥进行预冷或建造带有密封盖的气密式储存罐。我们得出结论，基于地面的高光谱遥感是温室气体监测和缓解的一种很有前景的方法。
