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Anthropogenic climate change due to, among other causes, unhindered CO2 emissions is a major concern worldwide. The post combustion capture (PCC) process using a solvent, known as chemical absorption, is currently the most effective way to reduce CO2 emissions from large point sources. However, high capital investment costs when using the conventional packed bed absorber/desorber technology and high energy requirements during solvent regeneration are the primary obstacles for its large-scale implementation. Different process intensification (PI) technologies to desorb CO2 from the solvent have been introduced to mitigate the energy consumption compared to the conventional packed bed technology. This work reviews different technologies for intensification of CO2 desorption. In this context, rotating packed beds, microreactors, and membrane contactors have been explored as potential alternatives to intensify the desorption because of their superior mass and heat transfer. Alternative energy sources like ultrasound and microwaves have also been used to improve the desorption performance of conventional equipments. PI can also be realized by using novel solvents with improved desorption kinetics in combination with intensification equipment. Thus in this review, a comprehensive assessment of different existing PI technologies based on regeneration energies and regeneration efficiencies relative to conventional technology is presented. The intensification of mass transfer for the different technologies is compared, and a new parameter, named the regeneration factor, is proposed to evaluate the performance of PI equipment. This study outlines the advances in process intensification of CO2 desorption technologies to date and presents an overview of the merits and limits of all technologies.

The use of intensified equipment, heavily advocated by academia, encounters several hurdles to break through in the chemical industry. This has several reasons, such as the high capital expenditures and the associated long depreciation times, the strong focus on robustness/availability, preferably 8000 h per year, or the fact that benefits are only incremental. Next to the fact that all chemical companies are anxious to be the first to demonstrate new technology, a methodology or a road map for process intensification implementation in the chemical industry is beneficial. The presented work makes an attempt to bridge this gap by proposing a methodology perspective based on coupling: (1) lab-scale fundamental experiments, (2) computational fluid dynamics simulations & optimization, and (3) process simulations & assessment. This could enable low-cost process intensification innovation and help to bring the targeted process intensification technology to technology readiness level 5 and higher at a faster pace.

To develop cost-effective CO2 capture technology process intensification will play a vital role. In this work, the capabilities of a gas-liquid vortex reactor (GLVR) as novel process intensification equipment are evaluated by studying its interphase mass transfer parameters to build up the fundamentals for its future application to for example, CO2 capture. The NaOH-CO2 chemisorption system and Danckwerts' model are applied to obtain the effective interfacial area and liquid-side mass transfer coefficient. Results show that the gas-liquid contact in the GLVR is capable of both generating a large interfacial area in a small reactor volume and creating a region with high-energy dissipation to improve mass transfer. A comparison of the volumetric mass transfer coefficients with data reported in literature for conventional and intensified reactor types confirms a superior mass transfer efficiency and, most importantly, a favorable energetic efficiency of the GLVR.