(421g) Systematic Process Design and Innovation Using Building Blocks

Discovery of novel chemical processes often requires creativity and “out-of-the-box” thinking as innovative solutions may lie outside the boundaries of the prevailing design paradigm. An example is process intensification that aims to outperform the existing processes with drastic improvement in performance metrics such as size, energy efficiency, cost, operability and safety [1-2]. However, identification of such intensified solutions at the conceptual design stage is a challenging task as there can be myriad of candidate process configurations. While optimization-based process synthesis approaches provide methodical tools for process design, they request pre-postulated superstructures with fixed connectivity and equipment types. This limits their scope for the discovery of unconventional design solutions.

To this end, building block-based process synthesis [3-6] offers significant advantages over classic superstructure-based process synthesis, as it relies on fundamental phenomena and tasks that constitute most chemical processes. In this work, first we will describe how a single block-based representation of these phenomena and tasks in a two-dimensional grid can be formulated, modeled using an MINLP and applied to solve wide ranges of process synthesis, integration and intensification problems. We will also discuss how this new representation can be used to generate novel process configurations without postulating the unit operations a priori. Each block in the grid can be assigned with a reaction operation and separation operations are represented via two neighboring blocks separated by a separation boundary. When linear split models are translated into block-variable (e.g. composition) dependent non-linear split models, rigorous separation models (e.g. tray-by-tray models) can be formulated within the same functional form. This enables systematic identification of the synergy between different operations (e.g. reaction and separation). We will demonstrate the benefits of the proposed approach via several problems and show that systematic process innovation and novel process discovery can be made possible via utilization of the building block-based superstructure.

[1] Stankiewicz, A. I., Moulijn, J. A. (2000). Process Intensification: Transforming Chemical Engineering. Chemical Engineering Progress, 1, 22–34.

[2] Lutze, P., Gani, R., Woodley, J. M. (2010). Process intensification: a perspective on process synthesis. Chemical Engineering Processing: Process Intensification, 49 (6), 547–558.

[3] Demirel, S. E., Li, J., and Hasan, M. M. F., (2017). Systematic Process Intensification using Building Blocks, Computers and Chemical Engineering, 105, 2-38.

[4] Li, J.; Demirel, S.E.; Hasan, M.M.F. Process Synthesis using Block Superstructure with Automated Flowsheet Generation and Optimization. AIChE Journal, 2018, under review.

[5] Li J., Demirel S.E., Hasan M.M.F. Process Integration using Block Superstructure. Industrial & Engineering Chemistry Research, 2018, 57: 4377–4398.

[6] Li J., Demirel S.E., Hasan M.M.F. Fuel Gas Network Synthesis Using Block Superstructure. Processes. 2018, 6(3): 23.