Performance of formulated solvent in handling of enriched CO2 flue gas stream

Carbon dioxide is considered to be one of the main contributors of the world climate change and flue gases from power plants emit the most CO2. To reduce the carbon footprint, CO2 capturing from flue gas becomes increasingly unavoidable to meet the CO2 emission requirements. CO2 removal with amine solvent has been gaining more and more attention as it may be the only feasible approach technically and economically. Formulated amine solvents are promising over traditional amine solvents to enhance the CO2 absorption considerably, Kohl and Nielsen (1997) [1]. It can be seen as a challenge for a CO2 removal unit to handle flue gas with a variety of CO2 concentrations, especially when the power plant is upgraded, in which its flue gas becomes enriched with CO2.In this paper, a comparison study is carried out to demonstrate the economic potential of capturing CO2 from enriched and non-rich CO2 flue gas stream with Monoethanolamine (MEA) and HTC formulated amine solvent, which is based on mixed amines. Flue gas from combined heat and power plant with 3.5 mol.% CO2 is used as a base case and enriching it with CO2 up to 9.2 mol.% is done to simulate the gas turbine exhaust gas recycling. The study shows that it is advantageous to use HTC formulated solvent over the conventional MEA solvent mainly due to its lower steam consumption, circulation rate, power requirements, and cooling water requirements. The study also shows that the working capacity of the HTC formulated solvent is higher than the MEA solvent. These findings result in significant operating cost savings when processing enriched CO2 flue gas stream using HTC formulated solvent.