Analysis of Energy Consumption Characteristics of Carbon Capture System in Coupled Membrane Condenser

Abstract

Aiming at the high energy consumption of coal fired units integrated with post-combustion CO2 capture systems, a carbon capture system integrated with membrane condenser based on the recovery potential of low-grade heat in flue gas by membrane condenser was proposed. Based on the chemical process simulation software Aspen plus and Tarong conventional carbon capture system as a reference, a comparative analysis was conducted on the changes in cold and hot load of carbon capture before and after the membrane condenser was used for process transformation, providing a basis for the design and operation of the device. When the carbon capture rate is 90%, the regeneration energy consumption of the new system is reduced to 4.275 MJ/kg CO2 compared with 4.341 MJ/kg CO2 of the conventional carbon capture system. Changing the key parameters of the new system, it is found that when the flue gas temperature and CO2 capture rate of the inlet and outlet of the membrane condenser are constant, the recovery rate of flue gas water increases and the regeneration energy consumption decreases. When the outlet flue gas temperature, flue gas water recovery rate and CO2 capture rate of membrane condenser are constant, the inlet flue gas temperature increases and the regeneration energy consumption decreases. In addition, the cooling load decreases with the increase of water recovery and increases with the increase of heat recovery.

Keywords

• carbon capture
• alcohol amine solution
• membrane condenser
• regeneration energy consumption