摘要

Short-chain haloolefins are being introduced as replacements for saturated halocarbons. The unifying chemical feature of haloolefins is the presence of a double bond which causes the atmospheric lifetimes to be significantly shorter than for the analogous saturated compounds. We discuss the atmospheric lifetimes, photochemical ozone creation potentials (POCPs), global warming potentials (GWPs), and ozone depletion potentials (ODPs) of haloolefins. The commercially relevant short-chain haloolefins CF3CF=CH2 (1234yf), trans-CF3CH=CHF (1234ze(Z)), CF3CF=CF2 (1216), cis-CF3CH=CHCl (1233zd(Z)), and trans-CF3-CH=CHCl (1233zd(E)) have short atmospheric lifetimes (days to weeks), negligible POCPs, negligible GWPs, and ODPs which do not differ materially from zero. In the concentrations expected in the environment their atmospheric degradation products will have a negligible impact on ecosystems. CF3CF=CH2 (1234yf), trans-CF3CH=CHF (1234ze(Z)), CF3CF=CF2 (1216), cis-CF3CH=CHCl (1233zd(Z)), and trans-CF3-CH=CHCl (1233zd(E)) are environmentally acceptable.

  • 出版日期2015-6