Process integration of solar thermal energy with natural gas combined cycle carbon capture

This project aims to investigate the effects of adding carbon capture to natural gas combined cycle (NGCC) power plants and to study the effect of solar thermal energy on the energy penalty associated with carbon capture for such a system. The gas turbine used in this study is the ALSTOM GT26, having dual combustion chambers. The capture process uses a 30%wt promoted K₂CO₃ solvent system. Alongside the standard case, other cases include an exhaust gas recirculation (EGR) and a pre-combustion case that utilises EGR with the capture taking place after the compression stage of the gas turbine. The solar thermal technology used in these simulations is a solar tower system capable of reaching 1000°C. The integration of the solar energy is used to provide heat to the first of the two combustion chambers in the gas turbine. The processes were modeled using ASPEN Plus® simulation software. Cases are optimized for 75% capture. For a standard NGCC (no solar) it was found that using EGR decreased the specific energy penalty as well as capture energy penalty. The pre-combustion case showed a reduction in the energy penalty over both the standard and EGR cases but at a reduced capture rate. The addition of solar thermal to these cases shows a reduction in the total energy penalty for the system. This is due to a reduction in the total CO₂ produced in the system and hence a reduction in the total amount of CO₂ captured.