Reactive distillation: Stepping up to the next level of process intensification

Reactive distillation (RD) is an efficient process intensification technique that integrates chemical reaction and distillation in a single apparatus. The process is also known as catalytic distillation when a solid catalyst is used. RD technology has many key advantages such as reduced capital investment and significant energy savings, as it can surpass equilibrium limitations, simplify complex processes, increase product selectivity and improve separation efficiency. However, RD is also constrained by thermodynamic requirements (related to volatility differences and heat of reaction), the need to align the reaction and distillation operating conditions, and the availability of catalysts that are active, selective and with sufficient longevity. This paper is the first to provide insights into novel integrated reactive distillation technologies that combine RD principles with other intensified distillation technologies – e.g. dividing-wall column (DWC), cyclic distillation, HiGee distillation, heat-integrated distillation column (HIDiC), and membrane-, microwave- or ultrasound-assisted distillation – potentially leading to the development of new processes and applications.