Oxycombustion for coal power plants: Advantages, solutions and projects

• Oxycombustion has become competitive for CO2 capture on coal power plants.
• Air Liquide developed specific Air Separation and Cryogenic Purification Units.
• Advantages include high efficiency and capture rate, flexibility and low emissions.
• Innovative solutions were developed such as energy storage and membrane combination.
• Projects updates include Total Lacq, CIUDEN, Callide Oxyfuel and FutureGen 2.0.

In recent years oxycombustion has emerged as one competitive option for CO2 capture on coal power plants.Air Liquide has been a key contributor to this evolution by developing technology blocks essential to the technical feasibility, flexibility and economic competitiveness of oxycombustion. This concerns in particular the ASU (Air Separation Unit) and the CPU (Cryogenic Purification Unit) which represent the largest CO2 capture costs (Fig. 1).The development carried out with boiler companies made oxycombustion potentially the most attractive carbon capture option for coal power plants. In addition to the highest efficiency, other advantages have become apparent:
• Its performances including:○cost effective CO2 recovery above 95%○CO2 purity greater than 99.99%○Low water usage○Near Zero Air emissions and in particular zero chemicals emissions○Very limited liquid and solid wastes
• Its flexibility in design and operation including potential for energy storage through cryogenic liquids
• A “Non chemical” routeThe paper illustrates innovative solutions and experiences developed to overcome technical challenges and to provide new capabilities to the oxycombustion route. It also provides updates of oxycombustion projects under way including a few retrofit projects: Total Lacq, CIUDEN, Callide Oxyfuel and FutureGen 2.0.