(194f) Multiple Criteria Decision Making for Sustainable Chemical Process Design

Sustainability is not just a rallying slogan, instead, it urgently calls upon engineers to think and act differently. In engineering design, the key to make a reality of the sustainability concept is to properly handle its complex nature and deeply rooted conflicts. Therefore, Multiple Criteria Decision Analysis (MCDA) is proposed as a general methodological framework, via which the “fuzzy” and “debatable” goal of sustainability can be practically achieved. The implementation of this framework takes a lot more than “filling a scorecard.” A four-step procedure needs to be first performed to formulate a sustainability-oriented design into a “standard” Multiple Criteria Decision Making (MCDM) problem. The attainment of a final “sustainable” design relies on making appropriate decisions that adapt to the specific problem situation. A solvent selection example is finally presented in order to demonstrate a proper way to explicitly handle the inherent conflicts in essentially all design problems for sustainability.

Chemical engineers, perhaps more than other practitioners, have been under enormous pressure to contribute to sustainability. In recent years, solutions to sustainability in chemical engineering have been flooded with all sorts of buzzwords, such as green chemistry, green engineering, cleaner production, industrial ecology, renewable energy, life cycle analysis, 3R (recycle, reuse, reduce), 4 or 10 factors, responsible care, waste minimization, eco-efficiency, eco-design, and a lot more. In literature, a myriad of techniques/methods/procedures/tools have been claimed to be capable of leading to a somewhat “sustainable” design.

In this paper, Multiple Criteria Decision Analysis (MCDA) is proposed to fill this vacancy. The rest will elaborate on the concept of sustainability as well as some underpinning challenges to be conquered in achieving a “sustainable” design. Details of the two critical steps in applying MCDA, namely, the formulation step that converts a sustainability-oriented design to a standard Multiple Criteria Decision Making (MCDM) problem and the solution step that aims to produce a final sustainable design by solving this MCDM will be shown and a solvent selection example, which showcases a justifiable way of handling the conflicts inherent in essentially all the design problems for sustainability will be discussed.