Synthesis design using mass related metrics, environmental metrics, and health metrics

The efforts to integrate environmental aspects, health aspects as well as safety aspects into chemical production has led to the development of measurable and thus objectifying metrics. The application of these metrics is considered to be most promising, especially during the earliest phases of synthesis design. However, the operability in daily work suffers from the lack of available data, or a large variety of data, and the complexity of data processing. If a life cycle assessment is not practical in the early development phase, environmental factor and process mass intensity can give a quick and reliable overview. I will show that this often says the same in advance as a subsequently prepared life cycle assessment. Readers will realise that, based on preparative descriptions, they can quickly determine these metrics for individual syntheses or extensive synthesis sequences applying the available software support. Environmental relevance in terms of persistence, bioaccumulation and toxicity (PBT) can be presented using a modification of the European ranking method ‘DART’ (Decision Analysis by Ranking Techniques). Based on corresponding PBT data, readers can determine a hazard score between 0 and 1 for any substance using the spreadsheet file provided, with which the mass of (potentially emitted) substances can be weighted. Occupational health can be represented using a modification of the recognized ‘Stoffenmanager’. Both concepts are presented and spreadsheet files are offered. This article is based on a presentation which was given at the Green Chemistry Postgraduate Summer School in Venice, 6th–10th July 2020.

Life cycle assessment of CO2 capture and utilization: a tutorial review

Capturing CO2 and using it as an alternative carbon feedstock for chemicals, fuels and materials has the potential to reduce both CO2 emissions and fossil resource depletion. To assess the actual environmental benefits of CO2 capture and utilization (CCU), life cycle assessment (LCA) is considered as suitable metric. To enhance the use of LCA of CCU, this tutorial review gives a jargon-free introduction of LCA of CCU directed at LCA novices. Nine particularly important aspects for conducting an LCA of CCU are identified and illustrated with CCU examples. These aspects, phrased as action items, can serve LCA novices as a checklist through all steps in LCA of CCU: from defining the LCA purpose and the system boundaries, over data collection and environmental impact computation, to interpretation and sensitivity analysis of the results. Finally, in the context of CCU, an outlook is given on recent developments in LCA that aim to cover all pillars of sustainability (people, planet, and profit).