(135b) Development of a CO2 Post Combustion Capture Technology Tailored for Gas Turbine Exhaust Using Solid Sorbents

In a joint development with JERA (Japan’s largest power generation company) and RITE (Research Institute of Innovative Technology for the Earth, Japanese center of excellence committed to research environmental issues), Chiyoda Corporation is developing a solid sorbent based CO₂ post combustion capture technology especially tailored for gas turbine exhaust under the fund of Japanese government (fund agent NEDO: New Energy and Industrial Technology Development Organization). Due to the low CO₂ concentration in gas turbine flue gas (3-5 vol%), although it has been technically possible to remove the CO₂ using conventional liquid amine based technology, the barrier of economic feasibility has been very high to implement such process to thermal power plants. The project aim is to halve the cost needed to remove the CO₂ from such dilute flue gas and be commercially ready by 2031.

In the project, we are scheduling a bench scale plant followed by few 10 tCO₂/day slip stream demonstration at JERA’s natural gas fired combined cycled power plant along with a joint demonstration of CO₂ utilization using the captured CO₂. We are still in the midst of deciding the CO₂ utilization technology, which could pose an opportunity to demonstrate their technology in Japan.

Amine based solvents has been the standard technology to capture and remove CO₂ from point source exhaust gas. However, due to amine’s viscosity and corrosiveness, amine has to be used in solution usually below 50 wt%. Since the temperature difference in the absorber and the regenerator is what drives the CO₂ to separate from the amine, this results in considerable amount of energy input to the water (sensible and latent heat) that accounts for more than half of the solution. A different approach is required to dramatically reduce the utility consumption. Our approach is to impregnate porous material with amine, which enables to avoid the use of water solution while gaining the benefit of using amine as the capture agent. The amine is being developed especially tailored to peak its absorption capacity at CO₂ partial pressure 4-5 kPa, which combined with the large surface area of porous carrier, enables the heat of absorption /desorption to be lowered.

From the process side of view, since the CO₂ content in the flue gas is dilute, the energy requirement per unit CO₂ removed for flue gas blower/fan is considerable, thus we have looked into low pressure loss structure of the absorber/desorber to reducing the electricity consumption of the process.

In the presentation, development activity regarding the solid sorbent and post combustion capture process will be discussed along with a project overview.