Remediation of oily soil using acidic sophorolipids micro-emulsion

A sophorolipids(SLs)micro-emulsion in Winsor type Ⅰ form was used for crude oil contaminated soil washing treatment.The micro-emulsion shows higher oil removal rate than SLs aqueous solution and diesel oil.The type Ⅰ micro-emulsion with w(SLs)=6%,w(NaCl)=1%,w(diesel)=13.36% gave a high oil removal rate of 95.6% and the eluate remained in type Ⅰ state.The recovered oil showed lower viscosity,mainly caused by the entering of diesel from the micro-emulsion phase into the oil phase and the lower removal rate of the heavier components,such as the resin and asphaltene.The initial heavily saline-alkaline soil changed into mildly saline-alkaline state after washing treatment,favoring the germination and growth of plants,with ryegrass showing better germination and growth effect than alfalfa.The ryegrass showed good phytoremediation effect on the contaminated soil after SLs micro-emulsion washing.The combination process of SL micro-emulsion washing and ryegrass phytoremediation is prospective for oily soil treatment.

Effect of monovalent anions on cationic Gemini micro-emulsion

Micro-emulsion usually consists of water, oil, surfactants and co-surfactants, and each component has an effect on the phase behavior and solubilization of the micro-emulsion. When the surfactant in the micro-emulsion system is quaternary ammonium cationic Gemini surfactant, the surfactant mainly combines with the anions in the salt. With the increase of salt concentration, the phase transformation of Winsor I → Winsor III → Winsor II occurred, but the optimum salinity and salt width are different because of the type of salt. The effects of 5 different kinds of monovalent anions, including C_6H_5SO_3^-, I-, Br-, NO_3^- and Cl-, on the phase behavior and solubilization of quaternary ammonium cationic Gemini micro-emulsion are researched by Winsor phase diagram. It is found that the effects of organic anions C_6H_5SO_3-and I-on the phase behavior and solubilization of quaternary ammonium cationic Gemini micro-emulsion are most significant, and the effects of Br-, NO_3^- and Cl-are less significant. Meanwhile, when the optimum solubilization is achieved, the amount of sodium benzoate is the least, indicating that the organic anion has stronger self-organization behavior with quaternary ammonium cationic Gemini surfactants.

Remediation of diesel oil contaminated sand by micro-emulsion

Micro-emulsion has unique advantages in repairing diesel oil contaminated sand due to its low interfacial tension and strong solubility.By Winsor phase diagram,it was found that with the increase of salinity,the phase of microemulsion transformed from WinsorⅠto WinsorⅢto WinsorⅡ.Under cryogenic electron microscope,it was observed that WinsorⅠwas O/W type,WinsorⅡwas W/O type,and WinsorⅢtype was bi-continuous type.The effect of inorganic salts,alcohol and temperature on the oil removal rate of diesel oil contaminated sand was investigated by static recovery of micro-emulsion precursor.The results showed that for the anionic microemulsion system,with the increase of salinity and alcohols,the oil yield of the upper phase increased first and then decreased,and the two components had a certain compensation effect.For non-ionic micro-emulsion system,with the increase of temperature,the oil yield in the upper phase rose first and then decreased.At the same time,the influence of leaching conditions on oil removal rate was investigated by one-dimensional sand column leaching experiment.It was found that for diesel oil contaminated sand with 15%oil content,when the formulation was 2.00 wt%SDBS,4.05 wt%n-butanol and 0.40 wt%sodium chloride,the optimum leaching conditions were leaching rate of 4 ml·min-1 and leaching amount of 400 ml.Under such conditions,the oil removal rate was up to 82.84%,that is,the oil content of the sand was reduced to 2.57%.Moreover,the micro-emulsion has good cyclicity,and it can still achieve high oil yield after six cycles.

Preparation and Field Application of a Novel Micro-emulsion as Heavy Oil Displacement Agent

A novel micro-emulsion was prepared by mixing an oil-soluble viscosity reducer,which was screened to aim at improving the heavy oil properties of Shengli oilfield with water-soluble surfactant and co-surfactant.The static viscosity reduction and oil washing performance of the micro-emulsion were investigated,and the field application of the microemulsion used as heavy oil displacement agent was also reported.Results showed that the micro-emulsion exhibited excellent viscosity reduction performance for the studied heavy oil samples.When heavy oil was mixed with 0.5%of the micro-emulsion,a stable oil-in-water heavy oil emulsion could be formed.After the content of the micro-emulsion was increased to 3.0%,the oil removing rate reached up to 80%.Field application of the micro-emulsion to the Pai-601-Ping-115 well and the Pai-601-Ping-123 well was shown to be effective by increasing the periodic oil production up to 203 tons.

One-dimensional numerical investigation on multicylinder gasoline engine fueled by micro-emulsions,CNG,and hydrogen in dual fuel mode

This research work is the novel state-of-the-art technology performed on multi-cylinder SI engine fueled compressed natural gas,emulsified fuel,and hydrogen as dual fuel.This work predicts the overall features of performance,combustion,and exhaust emissions of individual fuels based on AVL Boost simulation technology.Three types of alternative fuels have been compared and analyzed.The results show that hydrogen produces 20%more brake power than CNG and 25%more power than micro-emulsion fuel at 1500 r/min,which further increases the brake power of hydrogen,CNG,and micro-emulsions in the range of 25%,20%,and 15%at higher engine speeds of 2500-4000 r/min,respectively.In addition,the brake-specific fuel consumption is the lowest for 100%hydrogen,followed by CNG 100%and then micro-emulsions at 1500 r/min.At 2500-5000 r/min,there is a significant drop in brake-specific fuel consumption due to a lean mixture at higher engine speeds.The CO,HC,and NOx emissions significantly improve for hydrogen,CNG,and micro-emulsion fuel.Hydrogen fuel shows zero CO and HC emissions and is the main objective of this research to produce 0%carbon-based emissions with a slight increase in NOx emissions,and CNG shows 30%lower CO emissions than micro-emulsions and 21.5%less hydrocarbon emissions than micro-emulsion fuel at stoichiometric air/fuel ratio.

Preparation of double perovskite-type oxide LaSrFeCoO_6 for chemical looping steam methane reforming to produce syngas and hydrogen

Double-perovskite type oxide LaSrFeCoO_6 was used as oxygen carrier for chemical looping steam methane reforming（CL-SMR） due to its unique structure and reactivity. Solid-phase, amorphous alloy, sol-gel and micro-emulsion methods were used to prepare the LaSrFeCoO_6 samples, and the as-prepared samples were characterized by means of X-ray diffraction（XRD）, hydrogen temperature-programmed reduction（H_2-TPR）, X-ray photoelectron spectroscopy（XPS）, Brunauer-Emmett-Teller（BET） surface area. Results showed that the samples made by the four different methods exhibited pure crystalline perovskite structure. The ordered double perovskite LaSrFeCoO_6 was regarded as a regular arrangement of alternating FeO_6 and CoO_6 corner-shared octahedra, with La and Sr cations occupying the voids in between the octahedral. Because the La^（3＋） and Sr^（2＋） ions in A-site did not take part in reaction, the TPR patterns showed the reductive properties of the B-site metals. The reduction peaks at low temperature revealed the reduction of adsorbed oxygen on surface and combined with the reduction of Co^（3＋） to Co^（2＋） and to Co^0, while the reduction of Fe^（3＋） to Fe^（2＋） and the partial reduction of Fe^（2＋） to Fe^0 occurred at higher temperatures. From the point of view of the oxygen-donation ability, resistance to carbon formation, as well as hydrogen generation capacity, the sample made by micro-emulsion method exhibited the best reactivity. Its redox reactivity was very stable in ten successive cycles without deactivation. Compared to the single perovskite-type oxides LaFeO_3 and LaCoO_3, the double perovskite LaSrFeCoO_6 exhibited better syngas and hydrogen generation capacity.

Synthesis of SmOHCO_3 micro/nano particles from the coupling route of homogeneous precipitation with microemulsion

SmOHCO3micro/nano particles were prepared in water/oil （W/O） reverse microemulsion composed of cetyltrimethyl ammonium bromide （CTAB）, n-octane, n-butanol, Sm（NO3）3·6H2O and urea aqueous solution by the coupling route of homogeneous precipitation with microemulsion. The nanoparticles were characterized and analyzed by X-ray powder diffraction （XRD）, thermal gravimetric and differential thermal gravimetric analysis （TG-DTG）, Fourier transform infrared absorption spectra （FT-IR） and scan-ning electron microscope （SEM）. The results showed that the phase SmOHCO3 micro/nano particles was in agreement with pure or-thorhombic phase. The different morphologies of SmOHCO3 micro/nano particles with good monodispersity and size were obtained by regulating the reaction temperature and reaction time. Possible formation mechanisms of the morphological structure of SmO-HCO3 were proposed and discussed.

Experimental study on using SiO_(2) nanoparticles along with surfactant in an EOR process in micromodel

Surfactant flooding is a common chemical method for enhancing oil recovery.Recently,the simultaneous application of nanoparticles and chemical substances has been considered for improving the efficiency of EOR processes.In the present study,the microscopic and macroscopic efficiency of oil recovery in a linear micromodel in three injection cases of Sodium dodecyl sulfate(SDS)as an anionic surfactant,SiO_(2) nanoparticles,and simultaneous injection of nanoparticles and surfactant was investigated.In our study,adding the nanoparticles along with SDS(2000 ppm)decreased Interfacial tension by 84%,while the figure was 74%and only 10%when the surfactant and the nanoparticles were used alone,respectively.Seemingly,although the nanoparticles alone could not reduce IFT values,adding them to surfactant solution could strongly decrease the interfacial tension between oil and water,leading to enhancement of oil recovery.However,our findings showed that an optimum concentration of nanoparticles in surfactant solution must be used.In this regard,in low concentrations of nanoparticles,they were attached to the interface and IFT decreased due to absorption process.Nevertheless,in high concentrations,nanoparticles removed the surfactant from aqueous phase resulting in no free surfactant available in the bulk.Therefore,surfactant effectiveness in reducing IFT and alteration wettability decreased,and as a consequence,oil recovery efficiency dropped compared to lower nanoparticles’concentrations.Moreover,the results of sessile drop experiments and wettability measurements revealed that coating with either the surfactants or the nanoparticles could partially alter the wettability of surface to water-wet,while coating with the surfactants along with the nanoparticles could make a strongly water-wet surface.Seemingly,investigating the microscopic images of pores and throats showed a strong water-wet condition when the surfactant along with the nanoparticles was used.In addition,the results of flooding tests demonstrated that adding the nanoparticles to surfactant solution could increase the ultimate oil recovery significantly.Moreover,microscopic images confirmed that adding the nanoparticles to the surfactant solution can lead to forming oil-in-water and water-in-oil micro-emulsions due to ultra-low IFT.Obviously,this can result in improving the effectiveness of injection fluid to influence a wider range of porous media.

Ternary phase behavior of water microemulsified diesel-palm biodiesel

This paper aims to develop a new microemul- sions system comprising diesel and palm oil methyl ester （PME） that have the potential to be used as alternative fuels for diesel engines. The water-in-diesel-biodiesel micro- emulsions were prepared by applying PME mixed with diesel, non-ionic surfactants, co-surfaetants and water to make the water-in-oil （W/O） microemulsion system. This microemulsified fuel was achieved through low-energy microemulsification by using the constant composition method. The diesel used was mixed with four different concentrations of PME, i.e., 10% （w/w） （B10）, 20% （w/w） （B20）, 30% （w/w） （B30） and neat diesel （B0）. The amount of water was fixed at 20% （w/w）. The phase behavior of the water/mixed non-ionic surfactant/diesel-PME system were studied by constructing pseudoternary phase diagrams with the goal of formulating optimized systems. The results showed that the microemulsions were formed and stabilized with a mixture of non-ionic surfactants at a weight ratio of 80：20 at 20% （w/w）, and with mixed co-surfactants at a weight ratio of 25：75, 20：80 and 10：90 for B0, B10, B20 and B30 respectively. The particle size, kinematic viscosity at 40℃, refractive index, density, heating value, cloud point, pour pointand flash point of the selected water-in-diesel microemulsion were 19.40 nm （polydispersity of 0.012）, 12.86mm^2/s, 1.435, 0.8913g/mL, 31.87MJ/kg, 7.15℃, 10.5℃ and 46.5℃ respectively. The corresponding values of the water-in-diesel@ME selected were 20.72nm to 23.74nm, 13.02mme/s to 13.29mmZ/s, 1.442, 0.8939g/mL to 0.8990g/mL, 31.45MJ/kg to 27.34 MJ/kg, 7.2℃ to 6.8℃, 8.5℃ to 1.5℃ and 47.5℃ to 52.0℃. These preliminary findings were further studied as potential fuels for diesel engines.