Colloquia

Samenvatting

Carbon dioxide (CO₂) is one of the leading contributors to global warming due to its strong greenhouse effect. Its concentration has increased from approximately 260 ppm in pre-industrial times to over 410 ppm today. Solid-based carbon capture technologies, particularly those using amine-based sorbents like polyethylenimine (PEI), offer promising solutions for removing CO₂ from industrial gas streams. However, one of the key limitations in current carbon capture systems is the lack of direct, real-time indication of sorbent saturation. Instead, industries depend on indirect sensor data such as pressure, temperature, and humidity, which can often be misleading due to factors like low flow rates, minor pressure drops, and minimal mass uptake. Additionally, not all sorbents exhibit the mechanical stability required for use in various reactor types. This research explores the development and implementation of self-visualizing sorbents, functional materials that visibly change color upon CO₂ adsorption, enabling direct visualization of saturation levels. The study investigates the chemical integration of pH-sensitive indicators with PEI to achieve reliable and reversible visual signals upon exposure to CO₂. These functionalized particles were fabricated using in-air microfluidics, a technique that enables the continuous production of uniform sorbent particles with controlled morphology and embedded chemical functionality. The choice of indicators was guided by a combination of literature review and experimental testing to ensure effective response under realistic operating conditions. To evaluate the performance of these self-visualizing sorbents, a lab-scale transparent fixed-bed reactor was designed and constructed. This reactor allows for direct observation of CO₂ adsorption dynamics, making it possible to correlate visual saturation indicators with key process parameters such as mass uptake, pressure drop, and flow behavior. Additionally, mathematical modeling using standard fluid flow equations was applied to simulate and validate the reactor’s behavior under various configurations. The ultimate goal of this research is to develop a sorbent system that not only captures CO₂ efficiently but also provides a real-time visual indication of its operational state, thereby improving diagnostic accuracy and process control in carbon capture systems.