(606c) Sustainable Process Intensification Using Building Blocks

Growing demands for chemical products and increasing competition in the global market pose new challenges on the chemical process industry. Chemical processes need to produce more with less raw materials and utilities while generating less waste and reduced emissions. New projects are also required to consider sustainability of the process besides the economics throughout the project life-time. Process intensification (PI) provides means for more sustainable, cost effective, smaller and safer designs compared to their conventional counterparts [1]. Several systematic process intensification methods have been developed in the past that considers the trade-offs between sustainability and economics in process design [2-5]. These trade-offs can be illustrated through optimal Pareto fronts which, for given design alternatives, often describe the limits of our design achievements.

In this work, we ask whether systematic process intensification can provide novel solutions that are not bounded with these trade-offs and lead simultaneously more sustainable and economic designs. To this end, our recently proposed building block-based approach [6-9] provides several unique advantages towards incorporating both economic and sustainability objectives in process synthesis and intensification. Unlike traditional synthesis approaches that require superstructures with pre-postulated unit operation alternatives, our building block-based superstructure relies on physicochemical phenomena to automatically generate optimal intensified flowsheets. It is formed by building blocks positioned on a two-dimensional grid. A mixed-integer nonlinear optimization (MINLP)-based model is used to describe the superstructure. With this, novel intensified flowsheets can be generated through minimizing/maximizing several different objectives, e.g. economics, waste generation, utility consumption, etc. Specifically, we will introduce sustainability considerations through multi-objective optimization and search for pareto-optimal intensified flowsheet variants. This provides a unique approach for process design and intensification in which the effects of intensification on the process economics as well as on the sustainability can be observed. We will demonstrate the benefits of this design approach through several case studies with special focus on energy-intensive separations and reactive separation processes.

References:

1. Stankiewicz, A. I., Moulijn, J. A. (2000). Process Intensification: Transforming Chemical Engineering. Chemical Engineering Progress 1, 22–34.
2. Demirel, S. E., Li, J., & Hasan, M. M. F. (2019). Systematic process intensification. Current Opinion in Chemical Engineering. https://doi.org/10.1016/j.coche.2018.12.001
3. Tian, Y., Demirel, S. E., Hasan, M. M. F., Pistikopoulos, E. N. (2018). An Overview of Process Systems Engineering Approaches for Process Intensification: State of the Art. Chemical Engineering and Processing: Process Intensification, 133, 160-210.
4. Tula, A. K., Babi, D. K., Bottlaender, J., Eden, M. R., Gani, R. (2017). A computer-aided software-tool for sustainable process synthesis-intensification. Computers & Chemical Engineering, 105, 74-95.
5. El-Halwagi, M. M. (2017). A return on investment metric for incorporating sustainability in process integration and improvement projects. Clean Technologies and Environmental Policy, 19(2), 611-617.
6. Demirel, S. E., Li, J., and Hasan, M. M. F. (2017). Systematic Process Intensification using Building Blocks, Computers and Chemical Engineering, 105, 2-38.
7. Li, J., Demirel, S. E., & Hasan, M. M. F. (2018). Process integration using block superstructure. Industrial & Engineering Chemistry Research, 57(12), 4377-4398.
8. Li, J., Demirel, S.E. and Hasan, M.M.F. (2018). Process synthesis using block superstructure with automated flowsheet generation and optimization. AIChE Journal, 64(8), 3082-3100.
9. Demirel, S. E., Li, J., and Hasan, M. M. F. (2019). A General Framework for Process Synthesis, Integration, and Intensification. Industrial & Engineering Chemistry DOI: 10.1021/acs.iecr.8b05961.