Floating Production Storage and Offloading (FPSO) and Floating Liquefied Natural Gas (FLNG) systems are concepts that proved suitable for development of small or remote oil and gas fields in deeper water [1]. These floating systems are able to readily move to various hydrocarbon extraction sites in the far offshore and operate giant and marginal oil and gas fields [2]. The mixed phases of gas and oil extracted from the under-sea reservoir are separated, treated and packed on the deck into secure modules.

Packed beds are classical multiphase reactors widely employed for onboard oil and gas treatment owing to their simplicity in construction and large production volumes and reduced sloshing and rocking effect. In recent years, cyclic (or periodic/unsteady state) operation of trickle bed reactors (TBR) has achieved a lot of attention among researchers due to its substantial effect on improved reaction rate and reactor operational life [3]. Nevertheless, the implementation of the cyclic operation on offshore facilities and the investigation of the effect by marine swells on the hydrodynamic characteristics have not been addressed yet. From a pragmatic viewpoint, the TBR inclination and motion may have detrimental or beneficial effects on the performance of the reactor operating in the cyclic mode. To enlighten such effects, this study’s focus will be on the performance of a TBR (in terms of liquid distribution, wave propagation and attenuation, pressure drop) operating in the cyclic mode and subjected to simulated translational (heave, surge, and sway) and rotational (roll, pitch, and yaw) motions of floating systems. The motions are induced by means of a Hexapod robot ship motion simulator on which the TBR is secured while three capacitance wire mesh sensors (WMS) positioned at various heights of the TBR provide local and cross-correlated information on the hydrodynamic behavior under different strategies of cyclic operation. Various parameters such as propagation, attenuation, velocity, breakthrough amplitude, breakthrough time, plateau time, and decay time of wave are investigated in slow/fast mode and compared with the stationary vertical (onshore) and inclined configurations.

[1] Shimamure, Y; FPSO/FSO: State of the art; J Mar Sci Technol (2002) 7:59-70.

[2] GU, Y. and JU, Y.; LNG-FPSO: Offshore LNG solution; Front. Energy Power Eng. China 2008, 2(3): 249-255.

[3] Atta, A., Roy, S., Larachi, F., Nigam, K.D.P.; Cyclic operation of trickle bed reactors: A review; Chemical Engineering Science 115 (2014) 205-214.