Читать книгу Engineering Solutions for CO2 Conversion - Группа авторов - Страница 23

The MCFC can be used to separate CO₂ thanks to the functional reactions that occur inside the cell. By sending flue gas from a power plant to the cathode, the CO₂ from the flue gas is selectively separated and concentrated at the anode, in a mixture of water and small amounts of unreacted hydrogen and methane. The “cleaner flue gas” is delivered to the atmosphere with up to 70% less CO₂ content, which is transferred to the MCFC anode exhaust stream where it can be separated much more effectively, resulting in a high‐purity CO₂ flow. The main advantage in this process is that extra power is generated because the MCFC will be fueled and operated normally to carry out the separation, and it increases the overall efficiency of the power plant and compactness of the post‐combustion unit, while reduces the energy penalty. The modularity feature of MCFC systems allows to tailor the installation to the capture needs or gradually increases the size of the capture unit.

Figure 1.10 Superstructure of SOFC – CO₂ capture process configurations.

Source: Adams et al. [40].

One example of an MCFC and CO₂ capture system was developed by Fuel Cell Energy (FCE), namely, the Combined Electric Power and Carbon‐dioxide Separation (CEPACS). In the process of capturing >90% CO₂. In this configuration, the system can generate up to 351 MWe additional power (net AC), after compensating for the auxiliary power requirements of CO₂ capture and compression.⁵