(503a) Innovative Design and Systematic Process Intensification Using Building Blocks

Process intensification addresses the development of techniques that leads to substantially smaller, cleaner, safer, and more energy-efficient technologies. It also enables the innovative design of novel multi-functional units (e.g., Eastman Chemical methyl acetate process that performs extractive distillation, reactive distillation, reaction and distillation within a single column [1,2]). Intensification methodologies have been developed in the past, several of which are described in [3-8]. In this work, we address the following design and intensification challenges for both steady-state and dynamic processes: (i) how to systematically select and combine multiple phenomena to create new opportunities and obtain “out-of-the-box” design solutions, (ii) how to systematically identify intensified equipment and, at the same time, generate process flowsheets containing these equipment, (iii) how to select optimal configurations of intensified equipment and process flowsheets, and (iv) how to incorporate process intensification into process synthesis and optimization without a priori postulation of intensification alternatives. To address these questions within a single framework, we depart from the classical unit operation-based representation of process units, flowsheets and superstructures, and propose a new representation using finite building blocks [9]. In this representation, a physiochemical phenomenon, a processing task or a function can be represented using a single block or using two neighboring blocks and their boundaries. Other representations also exist in literature, including the modular [10,11] and phenomena building blocks (PBBs) [6,7]. Here, we propose a novel and general process superstructure which is an ensemble of only building blocks in two dimensions. Each block is denoted by its coordinate within the superstructure. A block can have entering and outgoing streams in both horizontal and vertical directions. An assembly of blocks of the same type obtains a classical unit, while an assembly of blocks with different types results in an intensified unit. The block superstructure encompasses numerous process equipment and flowsheet alternatives, and can be used to design, synthesize and intensify a chemical process without a priori postulation of these alternatives. The overall problem is formulated using a single mixed-integer nonlinear optimization (MINLP) model.

For dynamic intensification of multi-functional and periodic/cyclic processes, we propose a similar block superstructure, where each block represents a specific material performing a specific task for a specific time step. The superstructure is specifically suitable for the design of integrated, multi-functional and modular adsorption-reaction systems embedded within a single column while exploiting the dynamic interactions and trade-offs between different phenomena. Again, from the same superstructure, one can systematically generate variants of adsorption-reaction systems, including single- or multi-layered packed adsorption columns, reactors, pressure/temperature swing adsorption (PSA/TSA) processes, pressure and temperature swing adsorption (PTSA) processes, sorption-enhanced reaction processes (SERP), simulated moving bed chromatography (SMB) processes, and reactive SMB processes. Using this method, various intensified and modular processes can be designed for the utilization of both conventional and unconventional resources including stranded natural gas, contaminated shale gas, fuel gas or landfill gas to produce sustainable fuels and chemicals [12].

References:

[1] Agreda, V.H., Partin, L.R. (1984). Reactive distillation process for the production of methyl acetate. U.S. Patent 4,435,595.

[2] Siirola, J. J., (1996). Industrial applications of chemical process synthesis. Advances in Chemical Engineering 23, 1–62.

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

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

[5] Reay, D., Ramshaw, C., Harvey, A. (2013). Process Intensification: Engineering for Efficiency, Sustainability and Flexibility. Butterworth-Heinemann, Waltham, MA.

[6] Babi, D. K., Cruz, M. S., Gani, R. (2016). Fundamentals of process intensification: a process systems engineering view. In: Segovia-Hernández, J.G., Bonilla-Petriciolet, A. (Eds.), Process Intensification in Chemical Engineering., http://dx.doi.org/10.1007/978-3-319-28392-0 2.

[7] 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. http://doi.org/10.1016/j.compchemeng.2017.01.001.

[8] Baldea, M. (2015). From process integration to process intensification. Computers & Chemical Engineering, 81, 104-114.

[9] Demirel, S. E., Li, J., and Hasan, M. M. F., 2017. Systematic Process Intensification using Building Blocks, Computers and Chemical Engineering, http://dx.doi.org/10.1016/j.compchem eng.2017.01.04

[10] Papalexandri, K. P., Pistikopoulos, E. N. (1996). Generalized modular representation framework for process synthesis. AIChE Journal, 42(4), 1010-1032.

[11] Ismail, S. R., Proios, P., Pistikopoulos, E. N. (2001). Modular synthesis framework for combined separation/reaction systems. AIChE Journal, 47(3), 629-649.

[12] Iyer, S. S., Bajaj, I., Balasubramanian, P., Hasan, M. M. F. Modular Process Intensification of Carbon Capture and Conversion to Syngas. Submitted.