Mitigation against crude oil wax solidification using TES fin

Abstract

Crude oil stored in a cold subsea compartmented metal storage tank is constantly undergoing undesirable phase change. Thus, the prevention of the immobile wax formation for the ease of transportation in liquid phase becomes a daunting challenge. We hypothesize that a significant amount of thermal energy could be stored and discharged immediately after complete wax melting via embedded metallic fin(s) in retarding paraffin solidification process and to facilitate sustainable heating and shipment. This study employs the 2D enthalpy-based lattice Boltzmann method (LBM) that is capable of naturally capturing the innate propagation of mushy solid–liquid interface to explore the possibility of using thermal energy storage (TES) fin(s) in reducing the paraffin solidification process within a storage tank. In particular, the effects of cold wall cooling on compartment walls, selected adiabatic material, as well as TES-fin(s) positions and the corresponding aspect ratios to slow down paraffin solidification are discussed. Results show that the present optimized TES-fin configuration is capable of prolonging paraffin solidification by 94% immediately after complete melting. Interestingly, the mushy interface zone propagation rate during the paraffin wax solidification is reduced to a minimum, once the dimensionless length-to-width aspect ratio of TES-fin approaches 1.15 and most importantly, it is strongly position dependent. Overall, the present findings may serve as guidance for the long-term sustainable development in addressing the existing logistic issues on sustainable crude oil shipment from oil platforms.