Energy, Vol.167, 828-840, 2019
Theoretical assessment of integration of CCS in the Mexican electrical sector
This research evaluates the current most advanced and proven Gas Turbine (GT) technologies in a 1 x 1 scheme (400 MW on average) for their application in CO2 capture schemes. It has been demonstrated that the minimum energy required for the separation of CO2 is higher in a Natural Gas Combined Cycle (NGCC) than in a coal-fired power plant. Therefore, existing schemes were evaluated to assess the increased CO2 content in the Exhaust Gases (EG) for a NGCC in order to help reduce the energy penalty and the investment cost in CO2 capture systems. The schemes analyzed were: Exhaust Gas Recirculation (EGR), Evaporative Gas Turbine (EvGT), Supplementary Firing Combustion (SFC), External Firing combustion (EFC) and alternating systems with Selective Exhaust Gas Recycle (S-EGR) and hybridization. The most common GTs used in Mexico: Mitsubishi (15%), Siemens (41%) and General Electric (GE) (44%) including M - 501 GAC, SGT6-8000H and GE7HA.01 models were evaluated in Thermoflex 26 (R). For these, Levelized Costs of Electricity (LCOE) of 31.46, 31.18 and 31.05 USD/MWh, respectively, were obtained. GE offers the lowest LCOE and the EGR system presented the lowest energy penalty when the CO2 capture system was modeled in HYSYS V8.6 (R). Implementation of EGR helped to improve the energy efficiency of the NGCC and increased the content of CO2 from 4.2 to 7.1 mol% at 40%EGR. Similarly, EGR helped to reduce the LCOE in the integrated system with CO2 Capture by 10 USD/MWh. (C) 2018 Elsevier Ltd. All rights reserved.