Development of a Conceptual Framework for Evaluating the Flexibility of Future Chemical Processes

Abstract

Incorporating (operational) flexibility into process design has been a key approach to cope with uncertainties. The increasing penetration of renewables and the need for developing new low-carbon technologies will increase the demand for flexibility in chemical processes. This paper presents a state-ofthe-art review focusing on the origin, definition, and elements of flexibility in the chemical engineering context. The article points out a significant overlap in terminology and concepts, making it difficult to understand and compare flexibility potential and constraints among studies. Further, the paper identifies a lack of available metrics for assessing specific types of flexibility and the need for developing indicators for exploring the potential flexibility of novel chemical processes. The paper proposes a classification of flexibility types and provides an overview of design strategies that have been adopted so far to enable different types of flexibility. Finally, it offers a conceptual framework that can support designers to evaluate specific types of flexibility in early-stage assessments of novel chemical processes.

Integrated e-Methanol and Drop-in Fuels Hydrothermal Liquefaction Platform─Techno-Economic and GHG Emissions Assessment for Grid-Connected Plants under Flexible BECCU(S) Operation

“…In this, the ability of a process to vary throughput can be understood as a "volume" type of flexibility, in which equipment is designed to handle peaks in flow rates, and parallel units/ process lines can be switched on/off to adjust production level. 15 In the present study, these flexibility elements are present given that the process alternates between two operation modes; still, the aim is to evaluate the potential of such a concept without delving into process dynamics, which remain out the scope of the paper. Early assessment of flexibility in process design have been identified as crucial for the adoption of novel chemical processes, 15 but until now have remained unexplored in the field of HTL.…”

“…15 In the present study, these flexibility elements are present given that the process alternates between two operation modes; still, the aim is to evaluate the potential of such a concept without delving into process dynamics, which remain out the scope of the paper. Early assessment of flexibility in process design have been identified as crucial for the adoption of novel chemical processes, 15 but until now have remained unexplored in the field of HTL.…”

“…Flexibility in chemical processes has been approached from multiple perspectives in the literature. A recent review paper by Luo et al indicates a significant overlap in terminology and concepts, based on which a classification is proposed. In this, the ability of a process to vary throughput can be understood as a “volume” type of flexibility, in which equipment is designed to handle peaks in flow rates, and parallel units/process lines can be switched on/off to adjust production level .…”

“…A recent review paper by Luo et al indicates a significant overlap in terminology and concepts, based on which a classification is proposed. In this, the ability of a process to vary throughput can be understood as a “volume” type of flexibility, in which equipment is designed to handle peaks in flow rates, and parallel units/process lines can be switched on/off to adjust production level . In the present study, these flexibility elements are present given that the process alternates between two operation modes; still, the aim is to evaluate the potential of such a concept without delving into process dynamics, which remain out the scope of the paper.…”

Novel Reformulations for Modeling Uncertainty and Variations in a Framework for Chemical Process Design

“…In order to quantify a system's ability to cope with uncertainties, several metrics were suggested in the 1980s, including the flexibility index developed by Swaney and Grossmann 19 which has gained much attention in the literature, and is still subject to research (see, e.g., Di Pretoro et al, 20 da Silva et al, 21 and Luo et al 22 ). The flexibility index is a scalar value that expresses the share of the expected uncertainty space that is feasible.…”