Intensification of Droplet Dispersion by Using Multilayer Wire Mesh and Its Application in a Rotating Packed Bed

Experimental Investigation of Mass Transfer Intensification for CO2 Capture by Environment-Friendly Water Based Nanofluid Solvents in a Rotating Packed Bed

In this research, two intensification approaches for CO2 capture via a rotating packed bed (RPB) and nanofluids were examined simultaneously to maximize the experimental mass transfer coefficient. The two intensification approaches were done by using water as a green, environmentally friendly absorption solvent and as the base fluid for preparing nanofluids and also by using centrifugal acceleration in an RPB. Physicosorption of CO2 in an RPB was carried out by applying Al2O3, TiO2, and SiO2 nanofluids to intensify the mass transfer in water, and the operation parameters such as the angular speed of the rotor, concentration and type of nanoparticles, gas and liquid flow rates, and CO2 concentration in mass transfer intensification were evaluated and several nanofluids were selected to survey investigate how they affect the mass transfer at low pressure. The results show that the Al2O3 nanofluid was more effective than other nanofluids and that the 40 nm nanofluid of this type was more efficient than the 20 nm size. Therefore, a correlation is proposed in this paper for liquid volumetric mass transfer coefficient prediction that includes the microconvection of nanoparticles and surface tension.

A dispersion of a droplet flow on crossing wires in an air counterflow

Liquid dispersion on a wire mesh is a phenomenon that is utilized in many industrial applications, such as rotating packed beds. It is a very simple method of liquid atomization without a need for complex nozzles. This research focuses on an elementary case of a liquid dispersion on a crossing of two wires. Experiments were carried out in a wind tunnel to elucidate the influence of counterflow air velocity on a liquid sheet and droplets. High-speed camera was used to capture the impact of droplets on the crossing. Images were then processed using MATLAB® addon PIVlab. The effect of the input parameters, including a liquid flow rate in the range of 3.8 to 12 kg/h and air flow velocity varying from 0 to 9 m/s on the angle and velocity of dispersed droplets downstream of the crossing, was investigated. Finally, a qualitative description of the dispersion was evaluated. Results show that with an increasing liquid flow rate, the droplets dispersed in a wider angle. On the other hand, the influence of the air counterflow is significant only for low liquid flow rates. The atomization rate, determined by the number of small droplets, was better for higher liquid flow rates.

A Review of Modeling Rotating Packed Beds and Improving Their Parameters: Gas–Liquid Contact

The aim of this review is to investigate a kind of process intensification equipment called a rotating packed bed (RPB), which improves transport via centrifugal force in the gas–liquid field, especially by absorption. Different types of RPB, and their advantages and effects on hydrodynamics, mass transfer, and power consumption under available models, are analyzed. Moreover, different approaches to the modeling of RPB are discussed, their mass transfer characteristics and hydrodynamic features are compared, and all models are reviewed. A dimensional analysis showed that suitable dimensionless numbers could make for a more realistic definition of the system, and could be used for prototype scale-up and benchmarking purposes. Additionally, comparisons of the results demonstrated that Re, Gr, Sc, Fr, We, and shape factors are effective. In addition, a study of mass transfer models revealed that the contact zone was the main area of interest in previous studies, and this zone was not evaluated in the same way as packed beds. Moreover, CFD studies revealed that the realizable k-ε turbulence model and the VOF two-phase model, combined with experimental reaction or mass transfer equations for analyzing hydrodynamic and mass transfer coefficients, could help define an RPB system in a more realistic way.

High Efficient Biosynthesis 2-Ethylhexyl Palmitate in a Rotating Packed Bed Reactor

2-Ethylhexyl palmitate (2-EHP) is one of the important chemical products. Normally, 2-EHP is produced through the esterification. Since 2-EHP has a high viscosity, the mass transfer is significantly influenced with the product accumulation. In this work, a rotating packed bed reactor with intensive mixing was employed to solve the problem in the mass transfer during the enzymatic reaction. Under the optimal conditions, compared with the traditional continuous stirred-tank reactor (CSTR), the RPB reactor enhanced the final yield of 2-EHP, and shortened the reaction time to 1 h. In addition, the enzyme has a longer life-time in the RPB reactor, with production yield of closing to 99% after 9 batches. The results of this research indicated that the RPB has a great potential to be applied in the enzymatic production of 2-EHP. Application of the rotating packed bed in synthesis of 2-ethylhexyl palmitate.