(503c) A Study on Capacity Expansion Scenarios of Intensified Ethylene Oxide Process

There is significant ongoing research on process intensification, which has the potential to offer large reductions in energy and/or feedstock use in various chemical processes [1]. Reactors are integral unit operations in chemical conversion processes and their intensification provides significant opportunities for improving the overall process performance in terms of economics, safety, and environmental impact, however adequate downstream purification and feed pre-processing are vital to realizing those advantages. So in addition to reactor intensification, there may be a need for significant modification of the rest of the process, depending on the overall intensification objective.

Ethylene oxide (EO) is a large-volume chemical raw material used in a wide range of commodity products. It is produced through a highly exothermic partial oxidation reaction. Incidentally, ethylene oxide production is one of the most energy-intensive and inefficient processes in the chemical process industry [2]. Microfibrous Entrapped Catalyst (MFEC) is a highly conductive catalyst support that has been proven to effectively intensify reactors through conductive rather than convective heat transport and large surface area [3-5]. Significant reactor intensification is possible while controlling the ignition conditions inside the reactor in the conventional ethylene oxide process [6].

In this study, we assess the impact of reactor intensification on various capacity expansion scenarios such as greenfield, brownfield, and retrofitting of the downstream separation process for ethylene oxide production. We previously reported MFEC based reactors can have higher per-pass conversion resulting in a 19% reduction in overall production cost while keeping the reactor specification the same as the conventional process [6]. Further enhancement of the MFEC reactor has been achieved through the reduction of inerts, which reduced the reactor cost and dramatically increased the capacity of the process plant. We compared different capacity expansion ranges and corresponding expansion scenarios. Our results reveal that process retrofitting is a favorable option in medium expansion scenarios and greenfield construction in large expansion scenarios.

References

[1] Tian, Y., Demirel, S. E., Hasan, 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.

[2] Brueske, S., Kramer, C., & Fisher, A. (2015). Bandwidth Study on Energy Use and Potential Energy Saving Opportunities in US Chemical Manufacturing (No. DOE/EE-1229). Energetics.

[3] Cheng, X., Yang, H., & Tatarchuk, B. J. (2016). Microfibrous entrapped hybrid iron-based catalysts for Fischer–Tropsch synthesis. Catalysis Today, 273, 62-71.

[4] Choudhury, H. A., Cheng, X., Afzal, S., Prakash, A. V., Tatarchuk, B. J., & Elbashir, N. O. (2020). Understanding the deactivation process of a microfibrous entrapped cobalt catalyst in supercritical fluid Fischer-Tropsch synthesis. Catalysis Today, 343, 112-124.

[5] Sheng, M., Gonzalez, C. F., Yantz Jr, W. R., Cahela, D. R., Yang, H., Harris, D. R., & Tatarchuk, B. J. (2013). Micro scale heat transfer comparison between packed beds and microfibrous entrapped catalysts. Engineering Applications of Computational Fluid Mechanics, 7(4), 471-485.

[6] Mukta, C.B., Cremaschi, S., Eden, M. R., Tatarchuk, B. J. (2022). Techno-Economic Study of Intensified Ethylene Oxide Production Using High Thermal Conductivity Microfibrous Entrapped Catalyst. Computer Aided Chemical Engineering (Vol. 51, pp.1 Elsevier.