Jakober Chris A, Mara Steve L, Hsu Ying-Kuang, Herner Jorn D
a Research Division , California Air Resources Board , Sacramento , CA , USA.
J Air Waste Manag Assoc. 2015 Apr;65(4):404-12. doi: 10.1080/10962247.2014.996269.
Measuring greenhouse gas (GHG) source emissions provides data for validation of GHG inventories, which provide the foundation for climate change mitigation. Two Toyota RAV4 electric vehicles were outfitted with high-precision instrumentation to determine spatial and temporal resolution of GHGs (e.g., nitrous oxide, methane [CH4], and carbon dioxide [CO2]), and other gaseous species and particulate metrics found near emission sources. Mobile measurement platform (MMP) analytical performance was determined over relevant measurement time scales. Pollutant residence times through the sampling configuration were measured, ranging from 3 to 11 sec, enabling proper time alignment for spatial measurement of each respective analyte. Linear response range for GHG analytes was assessed across expected mixing ratio ranges, showing minimal regression and standard error differences between 5, 10, 30, and 60 sec sampling intervals and negligible differences between the two MMPs. GHG instrument drift shows deviation of less than 0.8% over a 24-hr measurement period. These MMPs were utilized in tracer-dilution experiments at a California landfill and natural gas compressor station (NGCS) to quantify CH4 emissions. Replicate landfill measurements during October 2009 yielded annual CH4 emissions estimates of 0.10±0.01, 0.11±0.01, and 0.12±0.02 million tonnes of CO2 equivalent (MTCO2E). These values compare favorably to California GHG Emissions Inventory figures for 2007, 2008, and 2009 of 0.123, 0.125, and 0.126 MTCO2E/yr, respectively, for this facility. Measurements to quantify NGCS boosting facility-wide emissions, during June 2010 yielded an equivalent of 5400±100 TCO2E/yr under steady-state operation. However, measurements during condensate transfer without operational vapor recovery yield an instantaneous emission rate of 2-4 times greater, but was estimated to only add 12 TCO2E/yr overall. This work displays the utility for mobile GHG measurements to validate existing measurement and modeling approaches, so emission inventory values can be confirmed and associated uncertainties reduced.
Measuring greenhouse gas (GHG) source emissions provides data and validation for GHG inventories, the foundation for climate change mitigation. Mobile measurement platforms with robust analytical instrumentation completed tracer-dilution experiments in California at a landfill and natural gas compressor station (NGCS) to quantify CH4 emissions. Data collected for landfill CH4 agree with the current California emissions inventory, while NGCS data show the possible variability from this type of facility. This work displays the utility of mobile GHG measurements to validate existing measurement and modeling approaches, such that emission inventory values can be confirmed, associated uncertainties reduced, and mitigation efforts quantified.
测量温室气体（GHG）源排放可为温室气体清单的验证提供数据，而温室气体清单是缓解气候变化的基础。两辆丰田RAV4电动汽车配备了高精度仪器，以确定温室气体（如一氧化二氮、甲烷[CH₄]和二氧化碳[CO₂]）以及排放源附近发现的其他气态物质和颗粒物指标的空间和时间分辨率。在相关测量时间尺度上确定了移动测量平台（MMP）的分析性能。测量了污染物通过采样配置的停留时间，范围为3至11秒，从而能够对每种分析物的空间测量进行适当的时间校准。在预期的混合比范围内评估了温室气体分析物的线性响应范围，结果表明在5、10、30和60秒采样间隔之间的回归和标准误差差异最小，并且两个MMP之间的差异可忽略不计。温室气体仪器漂移在24小时测量期内显示偏差小于0.8%。这些MMP被用于加利福尼亚州一个垃圾填埋场和天然气压缩站（NGCS）的示踪剂稀释实验，以量化CH₄排放。2009年10月对垃圾填埋场的重复测量得出，每年CH₄排放量估计为0.10±0.01、0.11±0.01和0.12±0.02百万吨二氧化碳当量（MTCO₂E）。这些值与该设施2007年、2008年和2009年加利福尼亚州温室气体排放清单中的数字0.123、0.125和0.126 MTCO₂E/年相比具有优势。2010年6月，为量化NGCS增压设施全范围排放而进行的测量得出，在稳态运行下相当于5400±100 TCO₂E/年。然而，在没有运行中的蒸汽回收的凝析液转移过程中的测量得出，瞬时排放率高出2至4倍，但估计总体上每年仅增加12 TCO₂E。这项工作展示了移动温室气体测量在验证现有测量和建模方法方面的实用性，因此可以确认排放清单值并减少相关不确定性。
测量温室气体（GHG）源排放可为温室气体清单提供数据和验证，而温室气体清单是缓解气候变化的基础。配备强大分析仪器的移动测量平台在加利福尼亚州的一个垃圾填埋场和天然气压缩站（NGCS）完成了示踪剂稀释实验，以量化CH₄排放。为垃圾填埋场CH₄收集的数据与当前加利福尼亚州的排放清单一致，而NGCS的数据显示了这类设施可能存在的变异性。这项工作展示了移动温室气体测量在验证现有测量和建模方法方面的实用性，这样可以确认排放清单值、减少相关不确定性并量化缓解措施。
