Centralized power generation with carbon capture on decommissioned offshore petroleum platforms

In this work, an offshore central power station is designed for supplying the electricity required during the lifetime of four identical productive floating, production, storage and offloading units (FPSO), aiming to increase the efficiency and alleviate the environmental burden that the business-as-usual utility systems are responsible for in offshore oil and gas activities. However, in face of the conflicting targets, intrinsic to offshore power generation systems (e.g. weight, area, cost and efficiency), along with prolonged offdesign operating conditions, a techno-economic assessment and optimization is necessary in order to determine the optimal configuration of power hub. By using a combined thermodynamic, environmental and economic analysis, together with space and weight allowance quantification, this work sheds light on the feasibility of offshore central power stations without or with carbon capture units and intended to be installed on decommissioned FPSOs, a novel proposal that reduces the initial investment cost. As a result, the advanced utility systems may provide higher overall power generation efficiencies (>35%) than existing simple cycle gas turbine (SCGT) configurations (about 30%), even at tenfold lower CO2 emissions. Moreover, envisaging future carbon taxation scenarios, an incremental economic analysis has found that the advanced power generation systems may also economically outperform the conventional offshore power plants for moderate carbon taxations. Lastly, the effect of the peak of electricity demand on the initial investment cost and the overall exergy efficiency of the power hub are briefly discussed in light of the delay in entry of operation between FPSOs.