THERMODYNAMIC ANALYSIS OF ENERGY RECOVERY TECHNOLOGIES IN A COGENERATION SYSTEM AIMING TO REDUCE CO2 EMISSIONS IN FPSO OFFSHORE PLATFORM
FPSO are floating vessels designed for extraction and processing of oil and natural gas from deep and ultradeep water regions.The facility’s self-sufficiency is achieved by the cogeneration plant, which is the main source of CO2 emissions and in this study will be object of work focusing on performance improvement and emissions reduction.In order to thermal and electrical supplying, the main cogeneration plant originally disposes of 3 main and 1 backup aeroderivative GE LM2500+ turbogenerator, which operational loads vary according to oil and gas separation and pumping processes. Additionally to the main cogeneration power plant, there is a secondary CO2 compression plant driven by 1 main and 1 backup aeroderivative GE LM2000 gas turbine, which drive CO2 reinjection process in oil well.Thermal and electrical demands vary according to crude oil composition and consequently, turbogenerators operational conditions are highly influenced not only by demand fluctuations but also by onsite atmospheric conditions. This work proposes, in possession of production and thermal and electrical demand curves, a thermodynamic analysis of original and alternative configurations under real operational conditions. Turbine Inlet Air Cooling system (TIAC) and Organic Rankine Cycle (ORC) were assumed to be simulated in order to improve exergetic efficiency and to reduce global CO2 emissions. Results point to both efficiency and emissions reduction gains, ranging up to 12 and 19%, respectively. On the other side, total weight and occupied area analysis show that unintended dimensions might be achieved.