Thermal regeneration of amines in vertical, inclined and oscillating CO2 packed-bed strippers for offshore floating applications

Abstract

CO2-monoethanolamine desorption process performance was studied for standard vertical, static inclined, and symmetric/asymmetric oscillating packed-bed columns via a dynamic three-dimensional model which links the macroscopic volume-averaged continuity, momentum, energy and species balance equations in the liquid and gas phases with the purpose to describe the stripping packed-bed columns aboard floating production, storage and offloading platforms. CO2 thermal desorption process is negatively impacted in static inclined and asymmetric oscillating packed-bed columns because of secondary liquid flow, generated by the buoyancy force in the radial and tangential directions, and its consequence on two-phase flow hydrodynamics and temperature fields. The continual variation of the extent of reverse secondary flow in symmetric oscillating packed-bed columns induces a symmetrical oscillatory two-phase flow follows by time-dependent waves for thermal fields and CO2 thermal desorption performance in the vicinity of the standard vertical stripper steady-state solution. Operation with extra heat allows to obtain higher CO2 desorption rates and avoids the deterioration of CO2 desorption performance in static inclined and asymmetric oscillating packed-bed columns. The extra heat is considerable when the inclined and asymmetric oscillating packed-bed columns are operated at elevated reboiler heat duty in the vertical state.