Assessment of the Resilience against Liquid Maldistribution of Monolith Packings under Offshore Floating Conditions

Abstract

The study provides insights for adapting commercially available packings to work on floating vessels in the marine context aiming at preserving performances similar to land-based packed-bed reactors. Specifically, liquid distribution for cocurrent gas–liquid downflow (U g = 0.0065–0.131 m/s and U l = 0.001–0.0078 m/s) inside monolith packings embarked on a hexapod emulator was compared against glass-bead containing trickle bed and open-cell foam packings using wire-mesh sensors under vertical, inclined, and rolling column conditions. Sensitivity of the tested internals with regard to liquid maldistribution was diagnosed and analyzed in terms of a maldistribution factor for the vertical/inclined and rolling columns. Liquid maldistribution was found to prevail at high gas and low liquid superficial velocities for the tested three packings regardless of column conditions. Monolith packed beds demonstrated superior robustness to counteract liquid maldistribution induced by bed static inclinations and roll motions. The glass-bead packed bed was susceptive to column inclination and rolling and suffered appreciable gas/liquid stratified flow leading to a loss of transverse liquid uniformity. Open-cell coarse foams equally failed as they were unable to preserve a homogeneous liquid distribution due to their poor radial spreading.

Mass Transfer Performance and Hydrodynamics of a Bubble Column Reactor at Offshore Floating Conditions

“…It is well known that sea swells can strongly impact the hydrodynamics and thus the performance of these reactors . So far, studies on the effect of sea swells mainly concerned floating packed beds and fluidized beds. − The authors of these studies embarked packed beds on a hexapod ship motion simulator to expose flow structure changes relevant to offshore floating applications. Spatially and time-resolved measurement techniques, such as wire-mesh sensors (WMS), were applied to quantify the gas–liquid distribution and liquid saturation.…”

Influence of Rotational and Translational Oscillations on the Drainage of Liquid in Floating Packed Beds

“…Reproducing offshore sea/swell movements under laboratory conditions is an essential step to ensure reliably functional unit-operation systems once commissioned for seagoing vessels. , As an example, marine applications of gas/oil processing have shaken up habits by contemplating gas–liquid-packed beds beyond their traditional use as stationary geometrical objects. Hence, the assessment of the scope of divergence in their operation under nonstationary/unstable sea conditions − has arisen as a legitimate query. Indeed, unlike their land-based analogs, the incessant movements induced by the erratic marine conditions inflict performance losses to the on-board fixed beds, depending on the extent of the oscillations of their host vessels in response to the swell and wind dynamics. ,− Safety considerations for emergency shutdown to be met in unfriendly sea areas with extreme weather conditions are an important aspect of the operation of packed-bed reactors. , Therefore, a key step to temporarily secure the processing units and to avert accidents onboards cannot afford to ignore the liquid drainage dynamics and how long it takes to free up in time the reactor fluid inventory.…”

Spreading of point‐source liquid spills in a thin rectangular packed bed under simulated marine conditions

“…Son et al [17][18][19] implemented an electrical resistance tomography technique to compare the liquid distribution and holdup for permanent inclination and roll motion of a column equipped with a structured packing. Zhang et al 26 compared through wire-mesh sensor measurements the transverse liquid distribution in oscillating beds, consisting of randomly packed beds, and open-cell foam and monolith units.…”