Application of Computational Fluid Dynamics (CFD) Modeling to the Gas-to-Liquid (GTL) Process on Offshore Plants | AIChE

Application of Computational Fluid Dynamics (CFD) Modeling to the Gas-to-Liquid (GTL) Process on Offshore Plants


Mendoza, J. A. - Presenter, Inha University
Hwang, S., Inha University
Since its inception, the definition of process intensification (PI) has been broadened from apparatus-centric ‘miniaturisation’ to the development of processing techniques that offer a drastic reduction in spatial- and energetic-requirements as well as in waste production. With the resulting enhancements in mixing, heat/mass transfer and all other benefits due to PI, many processes involving gas and liquid systems are becoming more proficient in performance and efficiency. On the other hand, the lack of focus in PI for processes involving solids handling has been attributed to the perception of fouling or blockage potentials in micro channels which have often been the technology of choice for miniaturisation. To address this, a clear understanding of industrially-relevant solids handling processes must be undertaken for proper equipment design, thereby remediating the aforementioned hindrances and hence, help facilitate the implementation of PI. These processes have been classified as precipitation/crystallisation, separation, granulation, mixing, particle coating, milling/grinding, catalytic reactions, particle classification, drying, thermal processing and bioprocessing.

In this presentation, five relevant powders- and solids-handling PI technologies are highlighted: (1) The Spinning Disk Reactor (SDR) applies a high centrifugal acceleration to liquids flowing on its surface, forming an extremely thin wavy film with a high surface area to volume ratio. This results in a rapid micro-mixing, creating high supersaturation levels, suitable for precipitation. (2) The Oscillatory Baffled Reactor (OBR) involves a fluidic oscillation in tubes equipped with baffles, resulting in enhanced mixing and heat/mass transfer. This technology has been applied for continuous crystallisation, particle suspension and catalytic reactions. (3) The Taylor-Couette reactors (TCRs) are composed of two differentially rotating concentric cylinders which are separated by a small gap. Flow within the annular space of the Taylor-Couette device experiences a sequence of hydrodynamic instabilities, from laminar Taylor vortex to turbulent regimes, as the rotational speed of the cylinder increased. This flow dynamics is usually characterised by the rotational Reynolds number or Taylor number. The vortex structure in various regimes of hydrodynamic instabilities could be exploited for various potential applications, including particles classification, crystallisation and granulation. (4) Microfluidics deal with the behaviour, precise control and manipulation of fluids that are geometrically constrained to a small scale, typically sub-millimetre. Micro-fluidized beds, for example, utilise the excellent mass and heat transfer characteristics in many applications e.g. kinetics measurement in solid catalysed reactions, detection of infectious bacteria, etc. (5) Twin screw granulator (TSG) is set to transform pharmaceutical processing by offering continuous granulation of drug formulations (currently carried out in batch), thus complying with Quality-by-Design concept, which highlights an automated real-time quality monitoring and control in tablet production.

For these and other solids-related PI technologies investigated in the Intensified-by-Design (IbD) project (funded by the EU Horizon 2020), detailed processing, control and fouling data are compiled in a cloud-based platform. The platform includes built-in design modules, which output datasets for users to facilitate reactor design and assembly, as well as a holistic process optimisation i.e. upstream and downstream intensified unit operations, solids handling capability, cleaning methods and the expected economic and environmental quantitative impacts.