Solvents define a major part of the environmental performance of processes in chemical industry and also impact on cost, safety and health issues. The idea of ''green'' solvents expresses the goal to minimize the environmental impact resulting from the use of solvents in chemical production.Here the question is raised of how to measure how ''green'' a solvent is. We propose a comprehensive framework for the environmental assessment of solvents that covers major aspects of the environmental performance of solvents in chemical production, as well as important health and safety issues. The framework combines the assessment of substance-specific hazards with the quantification of emissions and resource use over the full life-cycle of a solvent. The proposed framework is demonstrated on 26 organic solvents. Results show that simple alcohols (methanol, ethanol) or alkanes (heptane, hexane) are environmentally preferable solvents, whereas the use of dioxane, acetonitrile, acids, formaldehyde, and tetrahydrofuran is not recommendable from an environmental perspective. Additionally, a case study is presented in which the framework is applied for the assessment of various alcohol-water or pure alcohol mixtures used for solvolysis of p-methoxybenzoyl chloride. The results of this case study indicate that methanol-water or ethanol-water mixtures are environmentally favourable compared to pure alcohol or propanolwater mixtures. The two applications demonstrate that the presented framework is a useful instrument to select green solvents or environmentally sound solvent mixtures for processes in chemical industry. The same framework can also be used for a comprehensive assessment of new solvent technologies as soon as the present lack of data can be overcome.

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Distillation is one of the most important processes in the chemical industry. An environmental assessment of distillation processes is difficult because of the highly specific features of each distillation process. Life-cycle inventory (LCI) information is therefore scarce. The goal of this paper is to provide reliable data ranges for inventory flows of waste solvent distillation (i.e. amount of recovered distillate, consumption of steam, electricity, nitrogen, cooling water and ancillary product, and the generation of organic waste, wastewater, and outlet air). For this purpose, we collected data from approximately 150 waste solvent distillation processes from chemical industry and analyzed them statistically. The results of the statistical analysis compose generic data ranges for each LCI parameter. Where appropriate, the data of each LCI parameter have been subdivided according to the distillation technology or the waste solvent composition. Additionally, probability distributions have been fitted to the data of each LCI parameter, thus enabling quantitative uncertainty analysis (e.g. Monte Carlo Simulation). In a case study we illustrate the application of the inventory data ranges according to situations of differing data availability.