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The intermediate fluid vaporizer (IFV) owns various advantages over the other types of liquefied natural gas (LNG) vaporizers. Research findings related to the design of an IFV, including the configurational variations, selection of candidate working fluids, one-dimensional steady-state thermal model, computational fluid dynamics (CFD) model for thermal dynamic analysis and cold energy recovery, have been reviewed. It is proposed that further updates to the current one-dimensional thermal model are needed. A three-dimensional unsteady CFD model should be established for the instantaneous flow and heat transfer analysis. Integrating the LNG re-gasification and cold energy recovery will bring more complexity in the process design, optimization and operation.

Pressurized pipelines are the most reliable and cost-effective option for the long-distance transportation of CO2 from an emitter to an onshore storage site. Propagating or unstable factures are considered catastrophic pipeline failures, resulting in a massive escape of inventory within a short period of time. The decompression curve for CO2 exhibits a large drop in decompression wave speed at the phase transition pressure, leading to a higher driving force for crack propagation. The study of fracture control plans is very important for assessing the possibility of fracture propagation and preventing unstable fracturing along CO2 pipelines. Three full-bore rupture (FBR) experiments were performed using an industrial-scale (258 m long, 233 mm inner diameter) CO2 pipeline with initial CO2 states of gaseous, dense and supercritical phases, respectively. The relation between the decompression velocity and the pipeline fracture propagation velocity was analyzed during the process of buried CO2 pipeline release. A fracture propagation criterion was established for the buried CO2 pipeline. For the gaseous CO2 leakage, the pressure plateau corresponding to the decompression wave velocity only appeared near the closed end of the pipeline. For the dense CO2 leakage, the pressure plateau corresponding to the decompression wave velocity was observed near the saturation pressure after rapid decompression. For the supercritical CO2 leakage, the pressure plateau corresponding to the decompression wave velocity was observed in the stage when the supercritical CO2 transformed into the two phases of gas and liquid. Compared with the gaseous and dense CO2, for the supercritical CO2, the initial decompression wave velocity was the smallest, and the requirement of the pipeline safety factor was the highest.

The mass transfer characteristics of a gas–liquid continuous flow system accompanied by reaction in two commercial inline high shear mixers (HSMs) were evaluated by the sulphite oxidation method. The gas–liquid specific interfacial area, a, and the volumetric mass transfer coefficient, kLa, were measured under different operating conditions involving the rotor speed, the liquid flow rate, the gas flow rate and the surface tension. The results indicate that a and kLa increase with the rotor speed and liquid flow rate due to an increase of turbulence intensity. Both parameters increase slightly first but then decrease with the gas flow rate. For either the dual rows ultrafine-toothed or the single-row blade-screen configuration of HSMs, a increases while kLa decreases with the surfactant concentration, and both of them tend to be changeless at the surfactant concentration higher than 30 mg/L. Correlations for the specific interfacial area and the Sherwood number are obtained to guide the process design and ...

Single-pass continuous emulsifications were studied in kerosene– and silicone oil–aqueous systems with two inline high shear mixers (HSMs) adopting two main commercial configurations, including the dual-row ultrafine-toothed and the single-row blade–screen units. The effects of the processing parameters on the measured drop sizes and power consumptions were investigated. Bimodal drop size distributions (DSDs) were observed within both inline HSMs due to the inhomogeneity of the turbulence and shear levels accompanied with the recirculation and re-entrainment flow patterns. The drop sizes increase with increases in the dispersed-phase volume fraction and the continuous-phase flow rate and decrease with increases in the rotor speed and the continuous-phase viscosity. Correlations for the Sauter mean diameters were also obtained. The results obtained here are fundamental for the assessment of emulsification capability as well as the design and selection of inline HSMs.

The large eddy simulation and combined species transport method was validated for the residence time distribution (RTD) predictions of the pilot-scale in-line high shear mixers (HSMs) with ultrafine teeth. RTD characteristics were experimentally and numerically investigated under different rotor speeds and flowrates for the in-line HSM with double rows of inclined stator teeth. The exponential decays of the RTD curves indicate that the in-line HSM generally behaves like a mixed flow reactor, where the mixedness increases under higher rotor speeds and flowrates. It is indicated that the RTDs are greatly dependent on the HSM configurations, such as the shear gap widths, tip-to-base clearances, rows of the rotor and stator teeth, as well as patterns of the stator teeth. Defects of channeling, short circuiting and fluid re-entrainment are resulted from inefficient in-line HSM designs, such as those with large shear gap widths, large tip-to-base clearances, single rows of rotor and stator teeth, or improper angles of stator teeth. It is suggested that the in-line HSM with double rows of inclined stator teeth, narrow shear gap width and tip-to-base clearance has the advantage to provide intensified mass transport efficiency in the view of exploring novel chemical reactors.

High shear mixers (HSMs), characterized by their highly localized energy dissipation, are widely used in process industries for dispersed phase size reduction and reactive mixing. Research findings on typical applications of HSMs have been summarized in this paper, namely liquid–liquid emulsification, solid–liquid suspension and chemical reactions, with an emphasis on the emulsification due to relatively intensive research in this area. The design and control of HSMs as chemical reactors need comprehensive knowledge of both the reactions kinetics and the HSMs hydrodynamics. Therefore, hydrodynamics of HSMs in terms of power draw, flow pattern and energy dissipation are then particularly reviewed from both experimental fluid dynamics (EFD) measurements and computational fluid dynamics (CFD) simulations. Limited reports on the mass and heat transfer properties in HSMs are also introduced to demonstrate their potential applicability to intensify chemical reaction processes. Due to difficulties and challenges emerged in the experimentations, CFD tools play an important role in the design, optimization and scale-up of HSMs, yet the prediction accuracies still need to be improved.

Two main commercial in-line high shear mixer (HSM) configurations, including the dual rows ultrafine teethed and the single-row blade-screen in-line units, were investigated under the pump-fed mode...