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Integrated sustainability assessment and design of processes, supply chains, ecosystems and economy using life cycle modeling methods

Ghosh, Tapajyoti

Abstract Details

2019, Doctor of Philosophy, Ohio State University, Chemical Engineering.
Sustainable process design (SPD) has employed life cycle assessment (LCA) methods for determining the environmental impact while designing manufacturing technologies. However, deficiencies in LCA propagate to the design problem, resulting in suboptimal solutions. For example, despite the wide use of LCA for environmental profiling, the approach for determining the system boundary continues to be subjective and lacking in mathematical rigor. As a result, life cycle models are often developed in an ad-hoc manner, making it difficult to compare results across different studies. Significant environmental impacts may be inadvertently left out and ensuring inclusion of the most important activities in the selected system boundary is difficult to guarantee. Furthermore, conventional SPD has mostly ignored the supply and limits of ecological system services such as resource availability and pollution remediation among others. Not including flows to and from ecosystems in engineering has resulted in designs that exceed nature’s carrying capacity leading to unintended environmental degradation. Studies have already demonstrated that engineering designs incorporating ecosystems can be environmentally and economically superior to conventional techno-centric designs. However, spatial variability of ecosystems has not been considered in these studies. One more significant drawback of SPD is that it does not consider market components such as supply demand elasticities, changing taxes and prices which may have a significant effect on design decisions as well as on the environmental impacts. Conventional LCA directly compares a functional unit of a new technology with a base technology and determines which one is environmentally superior. It does not consider the introduction of this technology into society, its acceptance and the ripple effects that might occur due to such a technology in the real world. Such a problem can be thought of as being analogous to a chemical engineering design problem in a laboratory (attributional LCA) versus a full-sized industry (real world impacts). First, the thesis describes a simple application of LCA for determining the environmental benefit of carbon fiber composites over steel for producing vehicle components and point out the most important factors for multiplying their benefit. Next the thesis expands the application of LCA using a multiscale framework for multiobjective process optimization and engineering design of a bioethanol process. It develops a method for integrating byproduct flows between scales in the design framework. This thesis addresses the system boundary problem while designing processes by describing an algorithm for multiscale (hybrid) life cycle model generation and paves the way for a general mathematical procedure for combining data of different quality being used in a model at different resolutions and demonstrate the effect of parametric uncertainty on the final results. Next, the thesis provides an answer to the definition of sustainability by incorporating nature’s carrying capacity bounds on the engineering design of supply chains and processes. Using the novel Process-to-planet Techno ecological synergy framework, process design, supply chain design is performed in a multiscale approach while incorporating flows to and from ecosystems at different spatial scales. Ultimately, the thesis explores the conveniently ignored areas of economics, market effects, prices, elasticities of substitution and consequences by SPD. Consequently, a novel multiscale process design framework is developed that integrates economic equilibrium models with process design models to capture these unintended effects on process optimization and operation. Such an approach extends the bounds of engineering design to capture concealed phenomena such as Jevons paradox.
Bhavik R. Bakshi (Advisor)
306 p.

Recommended Citations

Citations

  • Ghosh, T. (2019). Integrated sustainability assessment and design of processes, supply chains, ecosystems and economy using life cycle modeling methods [Doctoral dissertation, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1563480013206943

    APA Style (7th edition)

  • Ghosh, Tapajyoti. Integrated sustainability assessment and design of processes, supply chains, ecosystems and economy using life cycle modeling methods. 2019. Ohio State University, Doctoral dissertation. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1563480013206943.

    MLA Style (8th edition)

  • Ghosh, Tapajyoti. "Integrated sustainability assessment and design of processes, supply chains, ecosystems and economy using life cycle modeling methods." Doctoral dissertation, Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1563480013206943

    Chicago Manual of Style (17th edition)