Abstract
The vapors which are generated during storage, transportation and handling of volatile organic compounds (VOC) such as organic solvents and gasoline are contributing factors to the development of photochemical smog (oxidants) when released to the atmosphere. A number of other environmental problems are also attributed to VOC emissions, and the adoption of membrane processes has been finding increasing public acceptance as the best available emission control technology.
In this article, the legislation trends which are affected by the growing public awareness of environmental issues caused by VOC emissions will be surveyed. The characteristics of the composite membranes and membrane modules for VOC emission control, which have been developed by Nitto Denko (Japan), MTR (USA) and GKSS (Germany), will be reported. Various membrane processes for VOC removal and recovery will be summarized, and the processes applied to the following commercialized plants will be described : 1) gasoline vapor recovery system by membrane-absorption, 2) gasoline vapor recovery system by absorption-membrane combined with activated carbon PSA, 3) condensation-membrane system to recover HCFC-123 or CFC-12 etc., and other examples.
