Energy and Pressure Drop Analysis of an Amine-Based CO2 Capture Pilot

Abstract

This thesis focuses on the energy study of an amine-based post-combustion capture pilot plant, as well as the analysis of a carbon capture test using a 30 wt% solution of monoethanolamine (MEA).

The pilot plant was constructed and is operated by the CRM Group in collaboration with the Universities of Liège and Mons, as well as industrial partners including AGC, Aperam, Carmeuse Technologies, and Prayon.

The pilot operates based on operating points defined by simulations from the University of Liège, and the flue gases are characterized by the gas compositions found in the industrial partners' processes.

The performance is evaluated by assessing the heat losses in the main components, such as the columns, the reboiler, and the heat exchangers, as well as in the many smaller components, such as pipes, valves, and sensors. Unaccounted thermal losses throughout the process create significant inefficiencies in pilot and industrial installations. For CO2 capture systems to be more viable overall and integrate more quickly into the current industrial infrastructure, their specific energy consumption must be decreased. To find inefficiencies and improve system performance, a precise measurement of heat losses is essential.

In addition, pressure losses are evaluated across the different sections of the installation. This enables precise evaluation of the energy usage related to fluid movement through the process equipment. The necessary pumping or compression work, as well as the overall process efficiency, are directly impacted by pressure drops. It is possible to determine which crucial parts or areas of the installation are mainly responsible for the pressure drop by measuring these losses at the pilot scale.

The objective is to set a benchmark for the anticipated pressure and heat losses in an industrial-scale carbon capture facility of comparable technology.

The total energy losses for a flue gas composition of 80% N2, 12% O2, and 8% CO2 (dry basis) were estimated at 9.69 kW and the pressure losses are equal to 1522.83 mbar. A specific reboiler duty of 8.4 GJ/ton CO2 was computed for a solvent flow rate of 1340 kg/h, flue gas flow rate of 662 kg/h, and reboiler duty of 67 kW.