Chemical Engineering Transactions (Sep 2012)
Energy Integration in an NGCC Plant with Post-Combustion CO<sub>2</sub> Capture – Systematic Methodology for Evaluating Process Alternatives
Abstract
Natural gas combined cycles (NGCC) with post-combustion CO2 capture is expected to be an important part of the solution in the future low-emission energy scenario. An overview of the literature shows that until recently there has been no effort to develop systematic methods to integrate the different units in the process. The CO2 capture process cannot be optimized without considering its integration into the power plant and the adaptation of existing process units to the new requirements defined by the CO2 capture process. With this in mind, a systematic energy integration methodology is presented in this work that evaluates the energy targets prior to design. The Sequential Framework for heat exchanger network synthesis is modified to develop the heat exchanger networks including the heat recovery steam generator. Process and component considerations when integrating steam extraction from the bottoming cycle are also discussed. Application of the methodology results in an improvement in efficiency of the overall process by 0.4 % points.