A novel approach for treatment of CO2 from fossil fired power plants, Part A: The integrated systems ITRPP

The environmental issues, due to the global warming caused by the rising concentration of greenhouse gases in the atmosphere, require new strategies aimed to increase power plants efficiencies and to reduce CO2 emissions. This two-paper work focuses on a different approach for capture and reduction of CO2 from flue gases of fossil fired power plant, with respect to conventional post-combustion tech- nologies. This approach consists of flue gases utilization as co-reactants in a catalytic process, the tri-reforming process, to generate a synthesis gas suitable in chemical and energy industries (methanol, DME, etc.). In fact, the further conversion of syngas to a transportation fuel, such as methanol, is an attractive solution to introduce near zero- emission technologies (i.e. fuel cells) in vehicular applications. In this Part A, integrated systems for co-generation of electrical power and synthesis gas useful for methanol production have been defined and their performance has been investigated considering different flue gases compositions. In Part B, in order to verify the environmental advantages and energy suitability of these systems, their comparison with conventional technology for methanol production is carried out. The integrated systems (ITRPP, Integrated Tri-Reforming Power Plant) consist of a power island, based on a thermal power plant, and a methane tri-reforming island in which the power plants’ exhausts react with methane to produce a synthesis gas used for methanol synthesis. As power island, a steam turbine power plant fuelled with coal and a gas turbine combined cycle fuelled with natural gas have been considered. The energy and environmental analysis of ITRPP systems (ITRPP-SC and ITRPP-CC) has been carried out by using thermochemical and thermodynamic models which have allowed to calculate the syngas composition, to define the energy and mass balances and to estimate the CO2 emissions for each ITRPP configuration. The repowering of the base power plants (steam turbine power plant and gas turbine combine cycle) is very high because of the large amount of steam produced in the tri- reforming island (in the ITRPP-SC is about of 64%, while in the ITRPP-CC is about of 105%). The reduction in the CO2 emissions has been estimated in 83% (15.4 vs. 93.4 kg/GJFuelinput) and 84% (8.9 vs. 56.2 kg/GJFuelinput) for the ITRPP-SC and ITRPP-CC respectively