No abstract

In this paper, the mentioned cycle has been transformed in a CO2 regenerative Ericsson-like cycle and therefore is named E-MATIANT. The removed CO2 can still be available at a pressure higher than the critical one (73 bar). When optimising the cycle, the calculated optimum pressure will be around 60 bar; this makes the technical issues easier to deal with than when using a supercritical fluid, namely the material strains and corrosion behavior. A sensitivity analysis is performed with respect to the CO2 delivery pressure in order to evaluate the performance changes. The fuel flexibility is an important asset of the newly designed cycle: mixtures of CO and H2 produced either in gasification or steam reforming processes can indeed be burnt in the combustion chamber. In a future work, the combination of a solid oxide fuel cell (SOFC) and this cycle both fed by a CO and H2 mixture will be considered as an option for the improvement of the global efficiency. If not fixed in a chemical or biological system, the delivered CO2 can be used in industry or in the enhancement of fossil fuels recovery from their deposits, with a marginal compression consumption work. In this paper, CO2 injection is used to enhance methane recovery from coal seams by some 20 to 30%, in comparison with water pumping. The depleted seam can afterwards be used as the host site for long run CO2 sequestration. As a conclusion, the combination of quasi-zero emission power plants with CO2 geological storage and enhanced fuel recovery provides a CO2 flow, otherwise considered as a waste or a byproduct, with an exergetic and a commercial added value. This makes this option a serious alternative to other CO2 control technologies.