Hot potassium carbonate-based CO2 capture with vacuum solvent regeneration: pilot plant experimental tests and process simulation

Carbon capture technologies have become crucial in reducing greenhouse gas emissions, combatting climate change, and reaching carbon neutrality while transitioning away from fossil fuels and petroleum-based industries. The hot potassium carbonate (HPC) process has emerged as an extremely promising solution among these technologies due to its effectiveness in capturing carbon dioxide (CO2) from a broad range of industrial flue gases. Offering potential advantages such as being environmentally friendly and requiring lower energy consumption at the regeneration stage, potassium carbonate (K2CO3) is being proposed as a greener alternative to the more established amine-based methods. However, the K2CO3 process also faces challenges that necessitate additional research to ensure high CO2 absorption capacity and promote its wider application at the industrial level. This master’s thesis investigates the performance of a hot potassium carbonate-based CO2 capture process with vacuum solvent regeneration through pilot plant experimental tests and process simulation. The first chapter provides a comprehensive review of the existing CO2 capture technologies, emphasising the benefits and drawbacks of potassium carbonate-based techniques. The feasibility and efficiency of the proposed process are evaluated by carrying out a pilot plant experimental campaign. The flexible structure of the pilot plant enables the configuration of many different process layouts, encompassing a wide range of operating parameters, to investigate the process's performance under different conditions. Given the scope of the thesis, three levels of stripping pressures were examined while modifying the other two parameters, namely the absorber pressure and the solvent flowrate, which were studied at two and four distinct levels, respectively. The second chapter discusses the experimental design and technique, while the third summarises the main findings. The thesis concludes with a process simulation using Aspen Plus® software to compare experimental and simulated results, providing useful insights into the influence of process variables on the overall carbon capture performance. The outcomes of this research contribute to the ongoing efforts in developing sustainable CO2 capture technologies and provide a solid basis for further process optimisation, potentially paving the way for the use of HPC-based CO2 capture in industrial settings.