Environmental Assessment of Waste-Solvent Treatment Options

Part II: General Rules of Thumb and Specific Recommendations


  • Christian Capello,

    1. Environmental sciences at the time the article was written. Currently, he works as a researcher in the Safety and Environmental Technology Group, ETH Zurich, Zurich, Switzerland
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  • Stefanie Hellweg,

    1. Safety and Environmental Technology Group, ETH Zurich, and is now professor of ecological systems design at the Institute of Environmental Engineering, ETH Zurich
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  • Konrad Hungerbühler

    1. Safety and Environmental Technology Group, ETH Zurich
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Address correspondence to:
Christian Capello
Safety and Environmental Technology Group
ETH Zurich, Wolfgang-Pauli Str. 10, HCI
CH-8093 Zurich, Switzerland


A comparison of various waste-solvent treatment technologies, such as distillation (rectification) and incineration in hazardous-waste-solvent incinerators and cement kilns, is presented for 45 solvents with respect to the environmental life-cycle impact. The environmental impact was calculated with the ecosolvent tool that was previously described in Part I of this work. A comprehensive sensitivity analysis was performed, and uncertainties were quantified by stochastic modeling in which various scenarios were considered. The results show that no single treatment technology is generally environmentally superior to any other but that, depending on the solvent mixture and the process conditions, each option may be optimal in certain cases. Nevertheless, various rules of thumb could be derived, and a results table is presented for the 45 solvents showing under which process conditions and amount of solvent recovery distillation is environmentally superior to incineration. On the basis of these results and the ecosolvent tool, an easily usable framework was developed that helps decision makers in chemical industries reduce environmental burdens throughout the solvent life cycle. With clear recommendations on the environmentally optimized waste-solvent treatment technology, the use of this framework contributes to more environmentally sustainable solvent management and thus represents a practical application of industrial ecology.