HOW CAN WAVES SIGNIFICANTLY IMPACT THE PERFORMANCE OF AN AMINE UNIT INSTALLED ON A FLNG?

摘要

Among the challenges to overcome and complete successfully a FLNG project, the design of the acid gas removal unitrnmight be of great importance: the experts shall address the question “What effect does the motion of the ship cause onrnthe gas sweetening process?”. It is necessary to build up accurate knowledge of the impact of the movements on therntowers operation, to first secure then to optimize the design of the processing units. Indeed both flooding and internalsrnefficiency significantly impacts towers sizing (diameter and height) and thus the whole FLNG project.rnTaking into account the multitude of factors such as liquid viscosity, height of packing, diameter of column,rnacceleration, liquid/gas flowrate, type of packing, and motions imposed on the system for columns design is veryrncomplex. Thus, Total, Prosernat and IFP Energies nouvelles have conducted a four-year research and developmentrnprogram at Heriot-Watt University to model mass transfer and hydraulics of a tilting and moving tower. In order tornbetter understand the impact of the column diameter on the results and to be able to scale-up the results, two differentrncolumn sizes were used and will be described.rnThe first phase of tests included static and pitch tests with varying periods and angles, at different liquid loads to maprnthe distortion of liquid distribution at several heights of packing. The data acquired have showed, depending onrnoperating conditions, a significant impact on liquid distribution in the packing bed, leading to well differentiated wettedrnzones. This work will give some examples to illustrate the impact of this phenomenon on the tower efficiency and therncorresponding impact on towers design.rnIn perspective, a second test phase has been launched at the beginning of 2015 with a column installed on a hexapod.rnThe machine, which has six degrees of freedom, will allow quantifying the impact of accelerations and 3D motions onrnthe hydraulics and mass transfer of a gas/liquid contacting tower, especially under surge and heave.