Study and Design of Flare Reduction Initiative in the Region: A Case Study of Gas Flaring Reduction at Oman Liquefied Natural Gas Company
Ahmed Al-Quwaitai
Department of M and IE, Process Operation and Maintenance Programme, Al-Hail, P.O.Box 2322, CPOSeeb111 Muscat, Sultanate of Oman
Pradeep Kumar Krishnan *
Department of Mechanical and Industrial Engineering, Caledonian College of Engineering, Al-Hail, P.O.Box 2322, CPOSeeb111 Muscat, Sultanate of Oman
*Author to whom correspondence should be addressed.
Abstract
In this paper examines the feasibility of eliminating flaring at Oman LNG Company by capturing the CO2present in the incoming gas during LNG ship gassing up operation. The gas containing CO2 is flared to prevent CO2 ice up and blockage at lower temperature. The project proposes a design and installation of two exchangers to cool the CO2 present to de-sublimation temperature of -132°C at which 99% of CO2solidifies on the heat exchanger fins which then direct the free CO2 gas to fuel gas system. A stream of cold LNG product available at -161°C on loading line was utilized as cooling medium to achieve the target temperature. The design takes into consideration energy optimization and efficiency of the system by which a multi-passes stream exchanger is used to pre-cool the incoming gas before it’s further cooled to CO2frosting point in the main exchanger.
A Honeywell UniSim software was used to simulate the process and the outputs were outlined. The results were found to be optimistic and targeted temperatures for 99% removal of CO2 were found to be achievable. The 7% of the total flaring responsible by gassing up operation can be eliminated.
Keywords: Gassing-up, flaring, de-sublimation, UniSim, frosts