Thermal Integration of a Flexible Calcium Looping CO₂ Capture System in an Existing Back-Up Coal Power Plant

Area of Science:

• Chemical Engineering
• Environmental Science
• Energy Systems

Background:

• Backup power plants, often utilizing older technology, contribute significantly to CO2 emissions.
• Existing CO2 capture technologies can be costly and inefficient, especially for intermittent operations.

Purpose of the Study:

• To develop and assess a flexible calcium looping system for efficient CO2 capture from backup power plants.
• To minimize the economic impact of CO2 capture by integrating with existing power plant infrastructure.

Main Methods:

• Integration of a calcium looping system with an existing backup power plant, including an oxy-fired calciner and carbonator.
• Utilizing the power plant's steam cycle for heat recovery from carbonator and calciner streams.
• Process simulation using Aspen Hysys for mass and heat balance calculations and thermal integration.

Main Results:

• Achieved 90% CO2 capture efficiency as CaCO3.
• Reduced the thermal input to the power plant by 12% through heat recovery.
• Calculated a net capture efficiency of 28% for CO2 from backup power plants.

Conclusions:

• The proposed flexible calcium looping system effectively captures CO2 from backup power plants.
• Heat integration significantly reduces capture costs and maintains power output.
• The system offers a viable solution for reducing emissions from essential but intermittently operating power facilities.