Amine scrubbing has been used to separate carbon dioxide (CO2) from natural gas and hydrogen since 1930. It is a robust technology and is ready to be tested and used on a larger scale for CO2 capture from coal-fired power plants. The minimum work requirement to separate CO2 from coal-fired flue gas and compress CO2 to 150 bar is 0.11 megawatt-hours per metric ton of CO2. Process and solvent improvements should reduce the energy consumption to 0.2 megawatt-hour per ton of CO2. Other advanced technologies will not provide energy-efficient or timely solutions to CO2 emission from conventional coal-fired power plants.

In recent years, Carbon Capture and Storage (Sequestration) (CCS) has been proposed as a potential method to allow the continued use of fossil-fuelled power stations whilst preventing emissions of CO 2 from reaching the atmosphere. Gas, coal (and biomass)-fired power stations can respond to changes in demand more readily than many other sources of electricity production, hence the importance of retaining them as an option in the energy mix. Here, we review the leading CO 2 capture technologies, available in the short and long term, and their technological maturity, before discussing CO 2 transport and storage. Current pilot plants and demonstrations are highlighted, as is the importance of optimising the CCS system as a whole. Other topics briefly discussed include the viability of both the capture of CO 2 from the air and CO 2 reutilisation as climate change mitigation strategies. Finally, we discuss the economic and legal aspects of CCS.

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A thermodynamically consistent model was developed for representing vapor-liquid equilibria in the acid gas (H2S, COJ-alkanolamine-water system. The model accounts for chemical equilibria in a rigorous manner. Activity coefficients are represented, with the Electrolyte-NRTL equation treating both long-range ion-ion interactions and local interactions between all true liquid-phase species. Both water and alkanolamine are treated as solvents. Adjustable parameters of the Electrolyte-NRTL equation, representing short-range binary interactions, were fitted on binary and Previous ModelsBecause of the difficulty in representing activity coefficients in concentrated electrolyte solutions, early VLE models for weak electrolyte models adopted empirical approaches that did not account for physical interactions. Van Krevelen et al. (1949) proposed a method for representing H2S, COz, and NH3 equilibrium partial pressures over aqueous solutions. In equations governing chemical equilibria, they used "apparent" equilibrium constants related to component concentrations rather than activities. In effect, they set, activity coefficients of all species to unity. Apparent equilibrium constants were fitted on experimental data to functions of ionic strength. Dankwerts and McNeil (1967) used this method to calculate vapor-and liquid-phase compositions in amine-C02-H20 systems.Kent and Eisenberg (1976) used a similar approach to represent H2S and COP equilibrium partial pressures over aqueous solutions of MEA and DEA. They also employed

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