Hydrodynamics and Mass Transfer Characteristics for Extractive Desulfurization of Diesel Using Highly Viscous Ionic Liquids in Microchannels: The Effect of the Phase Ratio and Temperature

Abstract

Microreactor technology shows great potential in the enhancement of liquid−liquid mass transfer, which is important especially when highly viscous fluids are involved. This provides an attractive way to intensify the extractive desulfurization (EDS) using ionic liquids (ILs) as an effective technique for ultralow-sulfur diesel production. This work concerns the extraction of dibenzothiophene in model diesel by [BMIM]PF 6 in a microchannel. The effects of the phase ratio and temperature on the hydrodynamics and mass transfer characteristics were investigated systematically. Higher temperature is beneficial for forming stable slug flow and droplet flow, as well as for increasing the overall mass transfer coefficient. The contributions of mass transfer during the droplet moving and forming stages were also discussed. Considerable mass transfer contribution (9−64% of the whole) was found during the droplet forming stage, and the mass transfer coefficient during the droplet moving stage can be well predicted by a two-film model.

Diesel Desulfurization Experiments in Microchannels with PEG 300: An Understanding of Extractive Deep Desulfurization

“…The statistical results presented in Table 2 show that the volumetric ratio was the most important variable of the experimental design employed. As shown by Ji et al, 4 Karamzadeh et al, 11 and Al-Azzawi et al, 20 the increase in the volumetric ratio (proportion between solvent and fuel) results in an increase in the interfacial area, providing more opportunities for the interaction between sulfur contaminants and solvents, leading to higher process efficiencies. This type of behavior was widely discussed by Jin et al 30 in which the authors used a mathematical formulation based on global mass transfer equations, exposing physical behaviors in microsystems.…”

“…3 The presence of sulfur-rich compounds in fuels causes a series of industrial and environmental problems, such as corrosion phenomena in petrochemical plants, poisoning, or deactivation of catalysts used in the treatment of crude oil. 4 Catalytic hydrodesulfurization (HDS) is a conventional technology for removal of sulfur compounds in the petrochemical industry. The process takes place in a fixed-bed reactor operating under severe conditions of temperature (573.2−673.2 K) and pressure (3.5−7.0 MPa) in the presence of bimetallic catalysts (Co−Mo or Ni−Mo).…”

A Review on Microchannel Fabrication Methods and Applications in Large-Scale and Prospective Industries

“…There was a flow of 0.01 to 1 µL/s 74) . There are numerous more processes that utilise microchannels to produce droplets and generate bubbles [337][338][339][340][341][342][343][344][345][346][347][348][349][350][351] . Chu and colleagues (2010) created bent rectangular tubes.…”

Extractive Desulfurization in Microchannel Contactors Using Deep Eutectic Solvents: Optimization Using Central Composite Design (CCD) and Flow Pattern Mapping

“…The main flow patterns observed in the microchannels are the slug flow, the droplet flow, the annular flow, and the parallel flow. − Based on our knowledge, there are fewer investigations on the flow pattern maps of liquid–liquid flow in microchannels compared to gas–liquid flow. Moreover, as reported in Table , there is a lack of information on the flow pattern of the EDS process in the microchannels. ,− It should be noted that the previous articles did not provide a sufficient illustration of the various flow regime types. Additionally, the application of RSM for the optimization of the EDS in microchannels is limited to the study of Al-Azzawi et al To fill this research gap, the main focus of the present study is to employ the RSM for the optimization of EDS in the microchannels, considering the sulfur removal and appropriate flow pattern.…”

“…In their study, the plug flow, the drop flow, the intermittent flow, and the annular flow were observed in different conditions, including mixture velocity, fuel to DES volume ratio, microchannel diameter, and different junction types. Ji et al 38 observed the slug flow, droplet flow, and irregular flow in the fuel/ionic liquid two-phase system in the microchannel at different flow ratio and temperature conditions. Santiago et al 39 reported the slug and droplet flow pattern in a microchannel contactor applied for the EDS process.…”