postCombustionCO2CaptureVerfahren

Post-combustion refers to processes that remove pollutants from exhaust gas after combustion. In carbon capture and storage, post-combustion carbon capture (PCC) targets CO2 in flue gases from burning fossil fuels or biomass. PCC is typically used to retrofit existing plants and to complement other capture approaches.

The most mature PCC technology uses solvent-based chemical absorption. Flue gas passes an aqueous amine solution in an absorber; CO2 is captured by the solvent and released in a stripper by heating. The regenerated solvent recirculates. The most studied solvents are monoethanolamine (MEA) and diethanolamine (DEA) or mixtures. Other approaches include solid sorbents (amine-functionalized materials, zeolites) and membranes.

Key equipment includes absorber and stripper towers, heat exchangers, and CO2 compression units. Energy demand is dominated by solvent regeneration, creating an energy penalty that can reduce net plant output. Challenges include solvent degradation and corrosion, solvent losses to the environment, and the need for pretreatment of flue gas to remove particulates and acidic gases.

Applications include retrofitting coal- or gas-fired power plants and some cement and refinery installations. Advantages are compatibility with existing combustion facilities and the ability to remove CO2 from post-combustion gas streams without altering the flame. Limitations are high capital costs, energy penalties, solvent management, and long payback times in some cases.

Status and outlook: PCC is among the most mature CCS options, with pilots and some commercial-scale deployments. Ongoing research focuses on reducing energy use, improving sorbents and solvents, and lowering overall costs to enable broader deployment alongside other decarbonization strategies.