Reactive distillation (RD) is a process intensification technique that offers major advantages over conventional technologies by enabling the integration of reaction and separation into a single apparatus. This integration introduces and exploits complex interaction between mass transfer, chemical reaction and hydrodynamics within an RD column; however, these complexities can hinder the adoption of RD by industry. Many approaches have been developed by the scientific community to advance understanding and to expedite the initialization of RD design at the conceptual level. This paper critically discusses recent developments in conceptual methods for synthesizing RD processes. This review paper is the first to consider the range of available approaches for assessing the technical feasibility, controllability, economic viability, and sustainability of RD units by taking into account various configurations in which RD is treated as a new unit operation, and as part of process synthesis in a different way of designing processes based on functions. The review also addresses complex configurations, such as advanced RD technologies. Special attention is paid to process modeling and simulation as well as to education. Knowledge gaps to be filled by further research are indicated.

This study is the first to provide a systematic approach to assessing the potential of advanced reactive distillation technologies to expand the applicability of reactive distillation. The work presented here focuses on the synthesis of advanced reactive distillation technologies, proposing a conceptually based methodology for early-stage screening. The methodology uses basic thermodynamic and kinetic data to navigate a decision-making flowchart in four steps: compositions and splits, basic properties and operating windows, kinetics, and phase equilibria. The results qualify advanced reactive distillation technologies as advantageous, technically feasible, or not applicable. Five industrially relevant case studies illustrate the application of the methodology to develop preliminary process flowsheets. The proposed methodology aims to guide technology selection using basic data while providing flexibility to meet the objectives of the design problem. This methodology contributes to integrating a technology-oriented approach normally followed in process intensification studies into a process systems engineering approach by developing a conceptual flowsheet in the early stages of process design.

Advanced reactive distillation technologies (ARDT) are often overlooked during process synthesis due to their complexity. This work proposes the use of operating windows with additional features to identify suitable operating limits for ARDT. Data needed to construct the operating windows are thermodynamic properties, kinetic parameters, constraints of materials and experimental methods, and heuristics. In addition, two new concepts are proposed to represent complex features: representative components and a sliding window. Results include the identification of suitable operating limits for ARDT to help assess their feasibility early in process design. The proposed approach is demonstrated by case studies. Methyl acetate production can be carried out at low pressures (0.5–3.6 atm), while lactic acid purification requires vacuum conditions (0.3–0.8 atm) to avoid thermal degradation. Tert-amyl methyl ether production was evaluated in two scenarios where the effect of side reactions is evidenced in a reduction of the reaction window due temperature limits to favour the main reaction over side reaction. This study is the first to evaluate advanced reactive distillation technologies using a graphical representation in an operating window to aid process synthesis, where the results provide key selection insights.