概括
1,1-二-2,2,2-三乙烯 (CFC-123) 是CFC-11的一个潜在替代品. 它的主要大气沉是与OH激素的反应,与CFC-11相比,导致寿命显著缩短,并减少了平流层注入量.
科学领域:
- 大气化学 大气化学
- 环境科学 环境科学
- 化学工程是化学工程的重要组成部分.
背景情况:
- 由于臭氧层和气候影响,三化甲 (CFC-11) 的使用受到限制.
- 1,1-二chloro-2,2,2-trifluoroethane (CFC-123) 被提议作为CFC-11的工业替代品.
- CFC-123是一种吸收红外线的化合物,预计在大气中不如CFC-11稳定.
研究的目的:
- 为了计算大气中CFC-123的化学破坏率.
- 确定CFC-123.3的主要大气沉降和寿命.
- 为了比较CFC-123与CFC-11在大气中的行为.
主要方法:
- 利用一个三维的全球大气模型.
- 通过各种大气过程计算CFC-123的化学破坏率.
- 估计了基于OH激素反应速率常数的稳定状态寿命.
主要成果:
- 碳-123的主要沉积点是热带层 (在12公里以下) 的OH激素的破坏,占其损失的88%.
- 最高的破坏率发生在2公里以下的赤道地区.
- 在稳定状态下,CFC-123的计算寿命为1.5年.
结论:
- 与CFC-11相比,CFC-123在大气中的寿命要短得多.
- 对于相同的排放率,CFC-11导致大气中的摩尔含量和平流层注入量明显高于CFC-123.
- CFC-123的热层OH基反应是其主要的去除途径,限制了平流层的影响.
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