Thermal Integration of CO₂ Compression Processes with Coal-Fired Power Plants Equipped with Carbon Capture

Technical Report · Mon Oct 01 04:00:00 EDT 2012

DOI:https://doi.org/10.2172/1064410· OSTI ID:1064410

Levy, Edward ^[1]

---

1. Lehigh Univ., Bethlehem, PA (United States); Lehigh University

Coal-fired power plants, equipped either with oxycombustion or post-combustion CO₂ capture, will require a CO₂ compression system to increase the pressure of the CO₂ to the level needed for sequestration. Most analyses show that CO₂ compression will have a significant effect on parasitic load, will be a major capital cost, and will contribute significantly to reduced unit efficiency. This project used first principle engineering analyses and computer simulations to determine the effects of utilizing compressor waste heat to improve power plant efficiency and increase net power output of coal-fired power plants with carbon capture. This was done for units with post combustion solvent-based CO₂ capture systems and for oxyfired power plants, firing bituminous, PRB and lignite coals. The thermal integration opportunities analyzed for oxycombustion capture are use of compressor waste heat to reheat recirculated flue gas, preheat boiler feedwater and predry high-moisture coals prior to pulverizing the coal. Among the thermal integration opportunities analyzed for post combustion capture systems are use of compressor waste heat and heat recovered from the stripper condenser to regenerate post-combustion CO₂ capture solvent, preheat boiler feedwater and predry high-moisture coals. The overall conclusion from the oxyfuel simulations is that thermal integration of compressor heat has the potential to improve net unit heat rate by up to 8.4 percent, but the actual magnitude of the improvement will depend on the type of heat sink used and to a lesser extent, compressor design and coal rank. The simulations of a unit with a MEA post combustion capture system showed that thermal integration of either compressor heat or stripper condenser heat to preheat boiler feedwater would result in heat rate improvements from 1.20 percent to 4.19 percent. The MEA capture simulations further showed that partial drying of low rank coals, done in combination with feedwater heating, would result in heat rate reductions of 7.43 percent for PRB coal and 10.45 percent for lignite.

• Research Organization: Lehigh Univ., Bethlehem, PA (United States)
• Sponsoring Organization: USDOE
• DOE Contract Number: FE0002146
• OSTI ID: 1064410
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
20 FOSSIL-FUELED POWER PLANTS
54 ENVIRONMENTAL SCIENCES