Towards a new, green and dynamic scoring tool, G2, to evaluate products and processes

Companies are progressively engaging to reduce the environmental footprint of their manufacturing processes, operations, and products. Today, there is still a gap between the need and the commitment to adopt green chemistry postures, those wanting to implement green chemistry require operative tools and methodologies to assess how green a process is with tangible metrics. The quantitative framework for measuring greenness and/or sustainability of chemical products and processes requires a method that evaluates the design and subsequently monitors the implementation and running of continuous chemical processes. This work introduces a green chemistry table/grid named “G2: greenness grid” and scale. The methodology develops along four steps: (i) for each principle of green chemistry a set of formulae are proposed to obtain values that quantify the principle, (ii) new principles are introduced and proposed (iii) the values derived from each principle are integrated/normalized into values between 0 and 1. (iv) The sum of all values yields an index score readable in the scale. To evaluate the G2 greeness grid a case study was analysed applying different green chemistry tools methodologies and results were compared: G2, LCA, Green Design, Green Motion, Chem21 and Green Chemistry Metric. The conclusion coming from this work supports that G2 was the tool able to integrate more green chemistry dimensions (15), to achieve a normalized score for the process studied and to establish a green Index outcome classifying it on a scale. According to the score of 8.82 obtained, the process under study was denominated “on Path” according to the qualitative scale herein proposed. The outcome shows the chemistry mechanisms that need to be improved to push the process to greener standards (score 15) and for consistent improvement.