•We first utilize oily sludge to fabricate three-dimensional hierarchical porous carbon (HPC) material.•The as-fabricated HPC exhibits super-high surface area and rational pore size distribution.•Outstanding performance of the HPC is demonstrated in all-solid-state flexible supercapacitor.•The cost of oily sludge-based HPC material is negligible.Rationally packed porous carbon with high ion-accessible surface area and low ion-transport resistance is proved to be an excellent candidate as electrode materials in high performance supercapacitors. However, its cost-effective fabrication still remains a significant challenge. Here, we report on a novel three-dimensional hierarchical porous carbon (HPC) synthesized via a facile and low-cost approach from hazardous waste oily sludge for the first time. Both the smart “self-template” effect and appropriate activation effect are crucial for the rational hierarchical porous structure. The “self-template” procedure is the key point for creating the skeleton of carbon, and the KOH activation process is able to regulate pore size distribution and increase specific surface area. The as-fabricated HPC possesses favorable features for supercapacitor, such as outstanding specific surface area (2561 m2 g−1), large pore volume (2.25 cm3 g−1), tunable and large range of pore size distribution. The HPC-based electrode can deliver an admirable capacitance of 348.1 F g−1 at 0.5 A g−1 and 94.3% capacitance retention at 5 A g−1 after 10,000 cycles in aqueous electrolyte. Remarkably, the all-solid-state HPC//HPC symmetric supercapacitor displays outstanding capacitance of 81.3 F g−1 at 0.5 A g−1 with high energy density of 7.22 W h kg−1. It is demonstrated that the strategy developed here would provide cost-effective production of HPC electrode material for high performance supercapacitors and offer a promising avenue of large-scale fabrication of HPC from other hazardous industrial waste.Download high-res image (187KB)Download full-size image

•The mechanism of SAGD produced liquid dehydration under pulsed DC electric field is investigated.•Dehydration efficiency increases firstly and then decreases with increasing electrical and operating parameters.•The electrical field parameters have remarkable influences on dehydration power, while operating parameters have rare effects.Separation methods utilizing high-frequency and high-voltage pulsed DC electric fields are extensively used in the oil and petroleum industries, where the occurrence of water-in-oil dispersions is highly unwelcome due to physical constraints, as well as the high maintenance costs required to treat these dispersions. This paper reports the studies of the effects of externally applied electric field parameters (e.g. voltage magnitude, electric frequency, and duty ratio), and operating parameters (e.g. operating temperature and operating time) on the dehydration process of steam-assisted gravity drainage (SAGD) produced ultra-heavy oil in a high-frequency pulsed electrical field. The investigations were performed in the DTS-4C airtight oil dehydration apparatus. The results illustrated that finding the optimum values of electric and operating parameters are of great significance to make a considerable increase of the dehydration efficiency. The optimum conditions obtained were as follows: voltage magnitude, 5.5 kV; electric frequency, 4.0 kHz; duty ratio, 0.5; operating temperature, 120 °C; and operating time, 3.0 h. Under the above conditions, the dehydration efficiency and post-electric-dehydration moisture content were 97.81% and 0.37 wt%, respectively, which are acceptable for refineries, and the dehydration power and electric current were positively correlated with the change of water content which influences the emulsion conductivity.Download high-res image (435KB)Download full-size image

•A novel liquid–liquid cyclone reactor (LLCR) for ionic liquid catalyzed isobutane alkylation (ILA) is proposed.•The reaction and separation process could occur in the same reactor.•A split radius is proposed to split the flow area in LLCR into: mixing area and upward flow area.•Dispersion of disperse phase performs well with the increase of turbulence intensity in LLCR.•Reducing the coalescence probability of kerosene droplet benefits the dispersion performance.To improve the existing problems of traditional reactors for isobutane alkylation catalyzed by ionic liquid，a novel liquid–liquid cyclone reactor (LLCR) was designed for the liquid–liquid heterogeneous reaction. The LLCR mainly includes two parts: a reaction chamber and a separation chamber, so the isobutene alkylation reaction and separation between the products and catalyst could occur in the same reactor. Compared with the traditional hydrocyclone, the LLCR consists of two kinds of inlets, one for the light phase and one for the heavy phase. The light phase is injected into the reactor through two symmetric tangential slots in the inlet, while the heavy phase inlet is an axial entry with a guided vane. The phase holdup distribution and dispersion uniformity of light phase in the LLCR were investigated using a novel sampling device and software MATLAB R2012b. One special radius was proposed, rs, which separated the reaction chamber into two parts: upward flow and mixing area. Experimental results indicate that when the total inlet flow is 2 m3/h, the flow field in the LLCR is irregular. Moreover, the discharge of the upward flow timely benefits the stability of flow field in the LLCR. Besides, a new parameter, dispersion uniformity of the light phase, β, was used to evaluate the dispersion performance of the light phase in LLCR. By analyzing the dispersion uniformity under different operational parameters, the dispersion of the light phase becomes more desirable under high total inlet flow, feed ratio and overflow ratio.A novel liquid–liquid cyclone reactor (LLCR) with two different kinds of inlet was proposed for isobutane alkylation catalyzed by ionic liquid, and a corresponding sampling device was applied. Based on this, the phase holdup distribution and dispersion performance of the light phase can be investigated.Download high-res image (175KB)Download full-size image

•A novel liquid–liquid cyclone reactor (LLCR) for ionic liquid catalyzed isobutane alkylation (ILA) is proposed.•The two phase flow in LLCR is simulated by Eulerian–Eulerian (CFD) model and Reynolds stress model (RSM).•There is a generally good agreement between the experimental and simulated data.•The LLCR has a good mixing and separation coupling effect.A novel liquid–liquid cyclone reactor (LLCR) was designed to enhance mixing and accelerate separation between the reaction products and catalyst during isobutane alkylation catalyzed by ionic liquid, and a three dimensional model was used to simulate the process. A Eulerian–Eulerian multiphase flow model and Reynolds Stress Model (RSM) were adopted to simulate two-phase flow in the LLCR. The simulated and experimental concentration distributions agreed reasonably well. Mixing between the two phases benefited from back-mixing around the overflow outlet as well as steady flow downstream of the reaction chamber. The parameter IM (mixing intensity) was used to evaluate the mixing performance. The two phases were separated in a timely manner in the separation chamber.Download high-res image (166KB)Download full-size imageA novel liquid–liquid cyclone reactor (LLCR) with two different kinds of inlet was proposed for isobutene alkylation catalyzed by ionic liquid. Based on this, the experimental and simulation investigation of concentration distribution and mixing intensity between two phases in the LLCR was presented.

•A novel liquid-liquid cyclone reactor for ionic liquid catalyzed isobutene alkylation (ILA)•The integration of reaction and separation process in the novel cyclone reactor•The species transport equation was used in the simulations to investigate the residence time distribution.To improve the existing problems of traditional isobutane alkylation catalyzed by ionic liquid reactors, a novel liquid-liquid cyclone reactor was designed for the liquid-liquid heterogeneous reaction. Compared with the traditional hydrocyclone, the novel cyclone reactor consists of two inlets, one for the light phase and one for the heavy phase. The light phase is injected into the reactor through two symmetric tangential slots in the inlet, while the heavy phase inlet is an axial entry with a guide vane. The trajectory and residence time distribution (RTD) of the light phase could influence the reaction process and product quality. In order to study the contact-mixing and separation mechanism of liquid-liquid in the novel cyclone reactor, the trajectory and residence time distribution in the reactor were investigated. Simulations using the species transport equation and experiments were performed on kerosene-water system. The tangential and radial dispersion process of oil was observed in the simulations. The simulation results showed that the mean residence time of the oil is between 0.6 s and 1.0 s under different operating parameters. The kerosene flow in the reactor is not a smooth flow or a complete mixing flow judging from the dimensionless variance. The separation efficiency in the simulated method was higher than 99%. The volume fraction of water in the overflow mixture was less than 5%. The deviation between the simulated and experimental results was no more than 5%, which indicated that the simulated results are reliable and accurate.A novel liquid-liquid cyclone reactor with two different kinds of inlet was proposed for isobutene alkylation catalyzed by ionic liquid, and the dispersion of the light phase.Download high-res image (87KB)Download full-size image

•Both Euler–Euler and Euler–Lagrange model can resolve the flow pattern in the separation zone of the dissolved air flotation tank.•Euler–Euler multiphase model makes a better prediction of the air distribution in the separation zone.•Larger bubbles enhance the stratified flow pattern for bubbles diameter ranging from 30μm to 50μm.•The height of “white water zone” in the separation zone decreases with the increase of bubble size.With computational fluid dynamics (CFD) methods, the influence of bubble size on the fluid dynamic behavior in a dissolved air flotation tank is investigated in this study. The choice of multiphase flow model between Euler–Euler and Euler–Lagrange approach is first addressed by comparing with the experimental results. The results indicate that Euler–Euler multiphase model is more suitable for the simulation of air/water flow in the DAF tank as it makes better performance in predicting air distribution. With the aid of Euler–Euler model, a systematic study was carried out to investigate the flow pattern and air distribution in the separation zone under bubble diameter from 30 μm to 70 μm. The results demonstrate that larger bubbles are conducive to the formation of stratified flow when bubble diameter ranges from 30 μm to 50 μm and show little impact on flow patterns when bubble diameter exceeds 50 μm. Bubble size has a significant influence on air distribution. Decreasing bubble size enlarges the height of “white water zone”.Air concentration distribution against height with various bubble sizes.The figure shows the air concentration distribution against height in the separation zone of the dissolved air flotation tank with various bubble diameters. The results indicate that bubble size has a significant impact on air distribution. If the area with air concentration above 1 ml/L is defined as the “white water zone”, the height of “white water zone” decreased with the increase of bubble diameter.

Non-aqueous solvent extraction is best characterized by higher bitumen recovery and minimal water consumption. In this study, single- and multi-stage counter-current solvent extractions of bitumen from Xinjiang oil sands were investigated. The particle size distributions of original oil sand samples, suspended particles, and extracted sands were analyzed. The results indicate that oil sand particles should be broken down to a size range of less than 450 μm and the median particle diameter should be approximately 268 μm. Bitumen recoveries for both the two- and three-stage counter-current processes are more than 93.5%, and the two-stage process is more effective for recovering bitumen than the single- and three-stage extractions based on a series of evaluation methods. The majority of the suspended solid particles are under 21 μm, and the residual solvent can be efficiently recovered through heating. The multi-stage counter-current solvent extraction has beneficial effects on the exploitation and utilization of Xinjiang oil sand ores.