温室气体全球变暖潜值的实验法评测

摘要

本文通过搭建模拟温室气体与大气中OH自由基等活性物种反应的实验装置,研究其大气化学特性,进而对全球变暖潜值(GWP)等环境影响指标进行评测.采用此装置,通过相对速率法测定了常见制冷剂1,1-二氟乙烷(R152a)与OH自由基在298 K和272 K的反应速率常数分别为(2.0±0.1)×104 m3/(mol.s)和(1.37±0.02)×104 m3/(mol·s),同时得到其红外吸收光谱.根据测试结果并利用现有计算模型得到大气寿命为1.4a,辐射效率(RE)为8.4×10-12 W/(m2·kg),20、100、500 a GWP分别为:474、129、37,与IPCC-AR5报告中的数据差异小于7％(测试误差范围内).%At present,the international communlty pays more attention on global warming issue caused by the increased emissions of greenhouse gases.In this study,we establish a set of simulated atmospheric experimental devices to investigate the reactions of greenhouse gases with OH radicals or other atmospheric oxidants and evaluate their atmospheric chemistry implications,e.g.,global warming potential (GWP).To estimate the accuracy of the experimental devices,the reaction rate constants of 1,l-difluoroethane (R152a) with OH radicals is measured using the relative rate method,and the infrared spectrum is obtained.The k,of R152a with OH radicals are found to be (2.0 ±0.1) × 104 m3/(mol·s) at 298 K and (1.37 ± 0.02) × 104 m3/(mol·s) at 272 K.The atmospheric lifetime and radiative efficiency (RE) are then estimated as 1.4 years and 8.4 × 10-12 W/(m2-kg),respectively.The GWPs (time horizons of 20,50,and 100 years) are estimated at 474,129,and 37,respectively.Our GWP values are in good agreement with those from IPCC-AR5 (discrepancy is less than 7％),which indicates the high reliability of our experimental apparatus.