High power generation efficiency and environmental performance are obtained in the integrated coal gasification combined cycle (IGCC) power plants. Hot gas clean-up is a key technology in IGCC systems. In this paper, a moving granular bed filter was constructed to examine the effect on collection efficiency when variations in the working parameters, namely, the mass flow rate, the filtration superficial velocity, and the amount of dust particulates at the inlet were introduced. A method to enhance particulate removal was proposed and tested in a lab-scale experiment. In addition, the study analyses the motion of gas flow in the inlet gas device of filter system. The results indicated a low amount of dust in the outlet of filter system when a mass flow rate of 0.008 kg/s and a filtration superficial velocity of 0.42 m/s were used. Furthermore, this new method is suitable for IGCC and other industrial areas involving high-temperature environments.

In this work, the removal of chromium (III) from aqueous waste solution by solvent extraction with 2-ethylhexyl phosphonic acid mono-2-ethylhexyl (P507) as extractant is investigated in a novel rotor-stator spinning disc reactor. The effect of rotational speed, volumetric flow rate and rotor-stator distance on extraction efficiency and volumetric mass transfer coefficient are studied. Experimental results indicates that the maximum values of extraction efficiency and volumetric mass transfer coefficient are 97.2 % and 0.40 1/s, respectively. The mass transfer performance inside the rotor-stator spinning disc reactor exceeds that of conventional reactors. Moreover, it is found that the extraction efficiency increases with the increase of rotational speed but with the decrease of volumetric flow rate and rotor-stator distance. The Volumetric mass transfer coefficient increases as both the rotational speed and volumetric flow rate increase, but decreases with the increase of rotor-stator distance. Furthermore, an analysis on the relationships between volumetric mass transfer coefficient and various parameters is launched by the grey correlation method. The calculation result shows good coincidence with the experimental data.

Numerical studies are carried out to explore thermo-fluidic transport characteristics of laminar flow through tubular heat exchangers using a compound technique, which is formed from the combination of twisted-tape with twisted-tube. The twisted-tape is installed inside a twisted-tube, which has an elliptical cross-section. Both minor and major arrangements are examined (TT-TT minor and TT-TT major), and the obtained results are compared with those of the straight-tube (ST) as well as straight-tube equipped with twisted-tape (ST-TT) and twisted-tube (TT). The comparison is made for three different levels of twist-pitch and five Reynolds numbers. Our results show that the dependence of transport characteristics on the enhanced models is strongly affected by both the twist-pitch and the Reynolds number. In contrast to the heat transfer performance, it is found that the pressure drop of the ST-TT is always more than that of the TT. However, the highest values are recorded for the TT-TT minor and the TT-TT major. At the range studied, the best overall hydrothermal performance is obtained for the TT-TT minor, while the ST-TT and the TT-TT major have comparable performances. The results display that increasing twist-pitch and Reynolds number leads to better overall performance in all models. The maximum performance index of 3.21 is found for the TT-TT minor at the Reynolds number of 1800. The results of the current analysis may be considered as a basis for selection of flow path geometry for design of tubular heat exchangers.

Mixing of a viscoplastic fluid using Scaba 6SRGT impellers in a cylindrical vessel has been studied. Cuts have been introduced in each blade of the impeller in order to reduce the power requirements. Effects of the cut-height (h2/D = 0, 0.015, 0.04, 0.065 and 0.09, respectively), cut-length (l/D = 0, 0.06, 0.12 and 0.18, respectively), and of the number of cuts (nb = 1, 2, 3, 4, and 5) on the hydrodynamics and power consumption were explored. The suggested designs, compared to the classical Scaba 6SRGT impeller, display a reduction in power number by about 20%, 19.9% and 66.6% when the cut-height, cut-length and number of cuts are changed from h2/D = 0 to 0.09, l/D = 0 to 0.18 and nb = 1 to 5, respectively. However, the increased surface area of cuts is accompanied by a reduction in the size of radial jet of fluid, resulting thus in a weakened axial flow and a decrease in cavern size. As a result, the best trade-off between the reduced power consumption and enlarged cavern size correspond to the case nb = 3, l/D = 0.12. The reduction in power number for this case is estimated to be as about 15%.

Rhamnolipids are widely investigated to control the growth of food pathogenic bacteria as well as repair environmental problems. This work was proposed to in situ recover rhamnolipids from the fermentation medium of Pseudomonas aeruginosa D1 through foam fractionation. The kinetic model of the fermentation process of Pseudomonas aeruginosa was established, solved and tested. The model fitted well with the experimental data. The results showed that the initial addition rhamnolipids concentration of 1.25 g/L had little effect on the growth of bacteria, but could significantly affect the synthesis of rhamnolipids. Under the suitable conditions of volumetric air flow rate 60 mL/min, loading liquid volume 100 mL, pore diameter of gas distributor 160 μm, the enrichment ratio and the recovery percentage of rhamnolipids reached 4.83 and 75.15%, respectively. Experimental results indicated that the maximum yield of rhamnolipids could be obtained by coupling foam fractionation with fermentation at 42 h, in which the synthesis rate of rhamnolipids was maximal. Moreover, the yield of rhamnolipids per unit volume of fermentation medium was 16.46 g/L, and the yield was 32.63% higher than that of uncoupled operation, and 13.04 and 10.32 % higher than those of coupled operation at other fermentation times.

The Thermal Electrochemical Co-drive System (TECS) has the advantages of high desorption rate and low energy consumption. However, the fluid flow and capture performance is still unknown in TECS. Thus, a comprehensive experiment and simulation work on TECS is performed to demonstrate the fluid flow and capture performance in a pilot-scale TECS. The reaction kinetics of the electrolyzed MEA-SG solution is discussed. A pilot-scale TECS is set up and gas-liquid two-phase flow model is developed for the TECS. According to the numerical computation and experiment, the gas-liquid two-phase flow field was analyzed under the thermal electrochemical co-drive conditions. The mechanism of CO2 capture was clearly understood. The synergy of thermal desorption and electrochemical desorption was quantified numerically. The results showed that the temperature of TECS was reduced below 333 K and the energy consumption amount was determined at 1.3 G J/t to 2.1 G J/t, which is much lower than the conventional process. LNG cold energy reduced the desorption energy consumption.

The present review (with 205 refs.) addresses the need for microdevices, presents the basic microfluidic equations and describes the relevant numerical and experimental approaches. Various types and designs of passive and active micromixers are presented. In addition, the relevant effective dimensionless or dimensional parameters and the fabrication technology for different micromixer types are introduced. Different general configurations of lamination, obstacle, convergence-divergence and curved-channel are discussed for passive micromixers. The active micromixers are categorized and described as pressure field driven, acoustic field driven, magnetic field driven, electric field driven and thermal field driven.

Recently designed, a multiframe flat sheet membrane contactors (MF-FSMC), consisting in ten parallel frames alternating aqueous and organic phase, was successfully used for chromium (VI) removal from aqueous solution. As a result, five chambers contain aqueous phase and the others contain the organic phase. Aliquat-336 was used as a carrier using polypropylene flat sheet membrane for Chromium (VI) removal. The results show that the extraction was more efficient by increasing the inlet chromium concentration and the number of frames but was not affected by the increasing of the thickness of frames (volume of chambers). To determine the interaction between different parameters, a full factorial design of experiment was used. The results show that the concentration of Aliquat-336 was the most important parameter, decreasing the efficiency of the system when increasing its concentration. Moreover, the temperature and the membrane contact aera have a positive effect on the extraction efficiency. However, no interaction effects were found in the chosen interval. The optimal values of different parameters are 10% for Aliquat-336 concentration, 59 cm2 for the membrane contact area and 40 °C for the temperature.