Ethylene Furnace Optimization for Efficiency, Run Length and NOx Emissions

Though research on process intensification has brought about many promising technologies including reactive distillation, divided wall columns, membrane reactors and task integrated columns, there is a lack of systematic methods for the identification and optimization of intensification alternatives at the flowsheet and equipment levels. Current superstructure-based process synthesis relies on pre-specified configurations and is unable to automatically construct novel equipment configurations for intensification. In this work, we depart from the classical unit operation-based representation of process units, flowsheets and superstructures and propose a new representation using fundamental building blocks which leads to a systematic method for simultaneous process design, synthesis and intensification. These building blocks can be associated with different process phenomena. 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. This allows to systematically identify and incorporate many intensification pathways using a general block-based superstructure at the equipment and flowsheet levels. We obtain the intensified process by optimizing a performance metric for given raw materials and product specifications, material properties and bounds on flow rates. The overall intensification problem is formulated using a single mixed-integer nonlinear optimization (MINLP) model which is solved using commercial solvers. In this presentation, we will demonstrate the applicability of our approach using several process design and intensification case studies.

References:

[1] Demirel, S.E., Li, J., Hasan, M.M.F. Systematic Process Intensification using Building Blocks. Submitted to Computers & Chemical Engineering.