Combustion of fossil fuels like coal, oil, or natural gas and also of biomass, bio-oil, and biogas with air implies combustion of hydrocarbons and results in flue gases consisting mainly of carbon dioxide, water vapor, nitrogen, and oxygen surplus [1][2][3][4]. Of course, pollutants like sulfur and nitrogen oxides and fly ash may also be contained in the flue gas, corresponding to the contents of the fuel. These gases and the fly ash have to be separated mainly before or in some cases also after the CO 2 separation to obtain CO 2 in the purity necessary for sequestration. These processes will be neglected in this chapter because such processes are already used in power plants.The amount of energy involved in absorption or adsorption and desorption is the same though not on the same temperature or pressure level. In addition, as CO 2 does not represent the overall minimum energy, there are further exothermal reactions possible, such as carbonate formation. This means that in addition to the amount of energy delivered by the combustion an additional amount of about 50% of the heating value is released by carbonate formation.Therefore, in principle, it should be possible to separate CO 2 from the flue gas without energy losses or even with a gain of additional energy if minerals for carbonate formation are available.Generally speaking to avoid losses and reach highest efficiencies it is necessary not only to combine known processes but to integrate them.
CO 2 -Emission Dependency on Fuel and Cycle EfficiencyThe CO 2 emission of power plants depends on both the fuel and the overall plant efficiency.The combustion of the mass of brown coal releasing 1 kWh th thermal energy simultaneously produces about m spCO2th ¼ 400 g-CO 2 per kWh th specific CO 2 -emisHandbook of Combustion Vol.5: New Technologies Edited by
