COLD ENERGY UTILIZATION FROM LNG REGASIFICATION PROCESS

• Main Author: ., Khuong Minh Cam Tu
• Format: Final Year Project
• Language: English
• Published: UNIVERSITI TEKNOLOGI PETRONAS 2012
• Subjects: TP Chemical technology
• Online Access: http://utpedia.utp.edu.my/6093/1/KHUONG%20MINH%20CAM%20TU%2012963_FYP%20THESIS_CHE.pdf; http://utpedia.utp.edu.my/6093/

Energy savings becomes one of the important effects to reduce the effect of global warming. Effective utilization of the cryogenic energy associated with LNG regasification gains more and more important to this energy issue. LNG regasification plant operates in combined cycle mode comprising ammonia Rankine cycle and a Brayton power cycle of combustion gas, open LNG cycle, interconnected by the heat transfer process in the recuperation system. LNG at low temperature of - 162oC and atmosphere pressure is gasified by absorbing heat from hot fluid of Rankine cycle. Typically ammonia is used as the working fluid for Rankine cycle. Then the LNG will be superheated by exhaust gas of Brayton cycle evaporation system as the cycle cold sink, the cycle condensation process can be achieved at a temperature much lower than ambient without consuming additional power. By using this thermal sink in a combined cycle plant that produces both power and gas, it is possible to recover cold energy from vaporization of LNG. Energy equilibrium equations and exergy equilibrium equation of each equipment in the cascading power cycle are established. Taken some operating parameters as key parameters, influences of these parameters on thermal efficiency and exergy efficiency of the cascading power cycle were analyzed. The net power overall after optimization is obtained at 22099.45kw compared to initial value which is only at 20175.41kW. The project objectives have been achieved. The research shows that it is able to identify the opportunity for cold energy recover from LNG regasification process by electricity generation and the optimization of heat recovery system is successfully achieved.