This study aims to analyze the influence of the polycyclic aromatic hydrocarbon (PAH) content in diesel on the physical and chemical properties of diesel soot particles. Four diesel fuels with different PAH content were tested on a 11.6 L direct- injection diesel engine. The raw particulate matter (PM) before the after-treatment devices was collected using the thermophoresis sampling system and the filter sampling system. A transmission electron microscope and Raman spectrometer are used to analyze the physical properties of the soot particles, including morphology, primary particle size distribution, and graphitization degree. A Fourier transform infrared spectrometer and thermogravimetric analyzer are
used to characterize the surface chemical composition and oxidation reactivity of soot particles, respectively. The results show that as the PAH content in the fuel decreases, the size of the primary soot particles decreases from 29.58 to 26.70 nm. The graphitization degree of soot particles first increases and then decreases, and the relative content of the aliphatic hydrocarbon functional groups of soot particles first decreases and then increases. The T10, T50, and T90 of soot from high-PAH fuel are 505.3, 589.3, and 623.5 °C, while those from low-PAH fuel are 480.1, 557.5, and 599.2 °C, respectively. This indicates that exhaust PM generated by the low-PAH fuel has poor oxidation reactivity. However, as the PAH content in fuel is further decreased, the excessively high cetane number may cause uneven mixing and incomplete combustion, leading to enhanced oxidation reactivity.

As a novel electric demulsification method, bidirectional pulsed electric field (BPEF) was employed to demulsify the surfactant stabilized oil-in-water (SSO/W) emulsion for oil/water separation in this work. The demulsification behavior, characteristics, and stages under BPEF were explored. It was discovered that BPEF drove SSO/W emulsion to move and form vortexes, during which the oil droplets aggregated and accumulated to generate an oil droplet layer (ODL). ODL subsequently transformed into a continuous oil layer (COL) leading to the demulsification and separation of SSO/W emulsion. The conversion rate of ODL to COL was defined and used to evaluate the demulsification process and reflect the coalescence ability and transformation efficiency of dispersed oil droplets into COL. Furthermore, the effects of BPEF voltage, frequency, duty cycle, ratio of pulse output time, and surfactant type and content on the demulsification performance were examined. The optimal values of BPEF parameters for demulsification operation were 400 V, 25 Hz, 50%, and 4:1. O/W emulsion containing anionic surfactant was apt to be demulsified by BPEF, nonionic surfactant took the second place and cationic surfactant was the most difficult. A high surfactant content was not conducive to the BPEF demulsification. This work is anticipated to provide useful guidance for oil/water separation and oil recovery from actual emulsified oily wastewater by BPEF.

Using K2S2O8-Na2SO3 as the redox initiation system, a hydrogen-bond-association-based dodecyl methacrylate system associative anti-shear drag reducer was synthesised by standard emulsion polymerisation. The reaction process was simple and gentle as well as safe and stable. Molecular design was carried out using molecular dynamics simulation methods. The results of infrared spectroscopy, thermogravimetric analysis, differential scanning calorimetry, gel chromatography, and laser light scattering showed that the reaction polymerisation was relatively complete, the product was uniform, the molecular weight distribution was controllable, and the synthesised polymer had good flexibility. The donor lauryl methacrylate-styrene-methacrylic acid (LMA-St-MAA) and acceptor lauryl methacrylate-styrene-dimethylaminoethyl methacrylate (LMA-St-DMA) polymers had an associative intermolecular interaction force, which increased the molecular cluster size of the associative system complex. The complex had good shear resistance, and the test results of the tube pump shear test showed that the synthesised associative oil-soluble polymer drag reduction system exhibited better drag reduction rate performance than poly-α-olefins over repeated cycles. The research results provide a reference plan for minimising the number of station-to-station inputs, thereby ensuring the stability of oil pipelines and reducing transportation costs.

Henry's coefficient of volatiles in the polymer system is a crucial parameter reflecting the gas-liquid equilibrium, which is very important for the devolatilization process. In this research, POE-cyclohexane and PDMS-hexane systems were taken as examples, using the gas-liquid equilibrium method, Henry's coefficient was obtained by measuring the gas phase equilibrium partial pressure when polymer solution containing different mass fractions of volatiles reached a saturated state. The effects of temperature, kinds of volatiles and polymer viscosity on the gas phase equilibrium partial pressure and Henry's coefficient of volatiles were investigated. Experimental results indicate that, with the increase of temperature and polymer viscosity, the gas phase equilibrium partial pressure and Henry's coefficient of volatile cyclohexane increase. As temperature increases, the solubility of gas in liquid decreases. In POE-cyclohexane system, the relationship between Henry's coefficient of cyclohexane and temperature can be expressed by lnH=389.39-244402.54×(1/T)+3.86×10^7×(1/T)^(2 ). While in the PDMS-cyclohexane, it can be expressed by lnH=106.57-60139.08×(1/T)+8.69×10^6×(1/T)^2 . In PDMS-hexane system, the gas phase equilibrium partial pressure and Henry's coefficient of n-hexane with straight chain structure are higher than those of cyclohexane with cyclic structure. Henry's coefficient obtained in this study can provide a reference for perfecting the devolatilization process and improving the devolatilization effect.

Introducing inorganic nanomaterials into a polymer matrix greatly improves the anticorrosion performance of epoxy coatings(EP); however, poor compatibility between the materials can limit the improvement in properties. In this work, based on the high interface compatibility of two-dimensional (2D) Co2(OH)2BDC (BDC = 1,4-benzenedicarboxylate) in the epoxy coating that we reported in previous work, we fabricated a 2D Co2(OH)2BDC-halloysite nanotube (HNT) nanocomposite have a structure consisting of alternating of nanosheets and nanotube by in situ synthesis. The nanocomposite was characterized by Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The mechanical and anticorrosion performance of the 2D Co2(OH)2BDC-HNT/EP coating was evaluated by mechanical tests and electrochemical impedance spectroscopy spectra. Compared with a conventional unreinforced epoxy coating, the 2D Co2(OH)2BDC-HNT/EP coating had higher mechanical strength and toughness, and the low-frequency impedance modulus of 2D Co2(OH)2BDC-HNT/EP coating was increased by three orders of magnitude, demonstrating the high corrosion resistance of our reinforced coating.

The FMOFs-[HeMIM]Cl/(ZnBr2)2, FMOFs-[CeMIM]Cl/(ZnBr2)2, and FMOFs-[AeMIM]Cl/(ZnBr2)2 were, respectively, immobilized in functional metal -organic framework materials (FMOFs). They were used to catalyze the cycloaddition reaction of carbon dioxide (CO2) and epoxides. The results from the investigation showed that the three metal-based ionic liquid catalysts were the target products. Under the conditions of reaction temperature 110 oC, reaction pressure 2.0 MPa, and catalyst dosage accounting for 2.0% of the mass of epoxide, the conversion of epoxide was 96.63% and the selectivity of propylene carbonate was 98.64%, thus forming the optimal catalyst FMOFs-[CeMIM]Cl/(ZnBr2)2. Moreover, the catalyst has no obvious change in catalytic performance after being recycled four times.

In this study, different loadings of x%Ni2P/γ-Al2O3 (x = 6%, 9%, 12%, 15%, 18%) catalysts with aluminum oxide (Al2O3) as the carrier, nickel chloride (NiCl2) as the nickel (Ni) source, and ammonium hypophosphite (NH4H2PO2) as the phosphorus (P) source were prepared by the equal volume impregnation method to investigate the effects of different loadings on the performance of the selective hydrogenation of diolefins and thiol etherification in LPG. The physicochemical properties of the catalysts were characterized by XRD, BET, SEM, TEM, H2-TPR, and XPS, and the catalytic activity of the catalysts was evaluated in a fixed-bed microreactor. The results showed that a change in the loading affected the catalyst crystalline phase structure and size, specific surface area, P coverage, active phase dispersion, and catalytic activity. At 6%, 9%, and 12% loadings the catalysts had an Ni phase but there was no obvious Ni2P phase in the nickel phosphide; at 15% loading a single Ni2P phase was obtained, and at 18% loading both Ni2P and Ni12P5 phases appeared. There was a P enrichment on the catalyst surface, and the higher the loading the more P species were enriched on the surface, but some of the P was lost during the catalyst reduction process due to the production of phosphine (PH3) gas. The 15%Ni2P/γ-Al2O3 catalyst had the largest Ni/Al ratio and the best dispersion. The Ni2P active phase size was small at about 4.25 nm and Ni2P was uniformly dispersed on the catalyst surface without agglomeration. The 15%Ni2P/γ-Al2O3 catalyst had the best catalytic activity at a pressure of 2.0 MPa, a liquid hourly space velocity (LHSV) of 3.0 h-1, and a hydrogen to hydrocarbon ratio of 12. The 1,3-butadiene conversion was 97.45% and the methanethiol removal was 100% at a temperature of 140°C.

Abstract: In this experiment, an EG/ChCl deep eutectic solvent (DES) was synthesized using choline chloride (ChCl) and ethylene glycol (EG) as the raw materials. The synthesized DES was characterized by Fourier transform infrared spectroscopy and thermogravimetric analysis. The results demonstrate the successful synthesis of DES. A certain amount of FeCl 3 and CuSO 4 was added to the DES to promote the absorption of H 2 S; thus, a Fe(III)-Cu(II) coupled DES desulfurization system was obtained. The effects of DES raw materials’ ratio, FeCl 3 concentration, water content, CuSO 4 concentration, and reaction temperature on the desulfurization efficiency and the regeneration conditions were studied. The results show that ChCl/EG DES with a molar ratio of 1:2 has a better desulfurization effect, and the addition of an appropriate amount of water can effectively promote the dissolution of CuSO 4 and the absorption of H 2 S. An appropriate increase in reaction temperature and CuSO 4 concentration would also promote the absorption of H 2 S. When the concentration of CuSO 4 in DES desulfurizer was 0.15 mol/L, the gas speed was 20 mL/min, and the sulfur capacity could reach 10.23 g/L. The desulfurizer could be regenerated by passing O 2 , and the desulfurization efficiency did not change much after repeated use of desulfurization-regeneration many times. The desulfurization product was characterized by XRD as rhombohedral sulfur.

A series of functionalized USY/SiO2 zeolite composite supports were synthesized using the coating coprecipitation method, with tetraethyl orthosilicate (TEOS) as the silicon source and different ratios of USY to TEOS. Active metals nickel (Ni) and molybdenum (Mo) were loaded onto the supports using the impregnation method. Finally, a series of hydrogenation catalysts were synthesized. The characterization results showed that, compared with the USY catalyst, the addition of a certain quantity of SiO2 resulted in the disappearance of the strong acid sites on the catalyst, the number of weak acid and medium strong acid sites decreased, and a certain number of secondary mesoporous structures were formed. The addition of SiO2 reduced the secondary cracking of benzene, toluene, xylene, and ethylbenzene (BTXE) effectively, while excessive amounts of SiO2 reduced the hydrogenation activity of the catalyst, leading to a decline in the final yield of BTXE. At a maximum SiO2 content of 45%, the hydrogenation depth of light cycle oil (LCO) reached an optimum value. The hydrogenation performance of LCO was investigated in a fixed bed reactor at 380 °C, 4 MPa, and H2/ oil volume ratio of 800:1, where the gasoline and diesel fractions reached 80.00% and 16.74%, respectively. NiMo-YS45 had the highest BTXE selectivity, and the final yield of BTXE reached 21.27%.

Carbon monoxide (CO) is an impurity gas that can poison the precious metal catalysts of hydrogen fuel cells, so it is necessary to separate CO from hydrogen. In this paper, an isovolumetric impregnation method was developed to prepare Cu(I)-supported activated carbon (AC), which is simple and easy to industrialize. The prepared cuprous chloride CuCl/AC adsorbent displayed a high CO adsorption capacity of 82.1 cm3/g and a high CO/H2 separation factor of 20 at 20 bar and 298 K. This material can adsorb and remove CO from CO/H2 mixed gas (5 μL/L CO-balanced H2) to less than 0.2 μL/L under dynamic flow conditions, and showed excellent regeneration performance. The results show that CuCl/AC is an effective adsorbent for separating trace CO in high-purity hydrogen.

Heterojunction composites were prepared by silane coupling agent grafting from synthesized graphitic carbon nitride (g-C3N4) and commercially available zirconia (ZrO2). The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR) spectroscopy, UV-vis diffuse reflectance spectroscopy (DRS), photoluminescence (PL) spectroscopy, and electrochemical impedance spectroscopy (EIS). The photocatalytic activity of the composites was evaluated by the degradation of methylene blue (MB) under visible light irradiation. The results showed that heterojunction composites of g-C3N4 and ZrO2 could be successfully prepared by coupling agent grafting. The optimal mass ratio of g-C3N4 and ZrO2 was 2:1, with an activity that was 3.8 times higher than g-C3N4 and 15.3 times higher than ZrO2. This was ascribed to the stronger light absorption, faster interfacial charge transfer, and lower photogenerated carrier recombination of the heterojunction composites.

Fluid catalytic cracking (FCC) is still a key process in the modern refining area, in which nickel-contamination for FCC catalyst could obviously increase the dry gas and coke yields and thus seriously affect the stability of FCC unit. Therefore, in this paper, B2O3-modified SBA-15 molecular sieves (B2O3/SBA-15) with different B2O3 contents were prepared, characterized and further used in preparation of Ni-tolerated FCC catalyst as matrix component. Characterization results suggested that, B2O3/SBA-15 samples possessed excellent Ni-passivation ability and structure properties of SBA-15 parent such as high-ordered mesopores, big surface area and high pore volume, which made B2O3/SBA-15 sample could greatly improve the Ni-tolerance performance of FCC catalyst by promoting the Structure properties and Ni-passivation ability of the prepared FCC catalyst. The evaluation results of heavy oil catalytic cracking indicated that, at the same Ni-contamination condition, the dry gas, coke and heavy oil yields for the FCC catalyst containing B2O3/SBA-15 could obviously decrease by 0.92, 1.65 and 1.26 percentage points respectively with total liquids yield increasing by 3.83 percentage points in compared with conventional FCC catalyst.

TiO2 is a promising photocatalyst, but the limited contact area of liquid-liquid interface and low catalytic efficiency caused by catalysts with large particle size and uneven distribution restrict the practical application. As an effective process intensification equipment, the impinging stream-rotating packed bed (IS-RPB) overcomes the mixing limitation of traditional stirred tank reactor, and provides a micro-mixing environment at the molecular scale for liquid-liquid two phase, which could reduce the particle size and distribution range. Cu/N-TiO2 nanoparticles were successfully prepared by one-step precipitation method using urea as the nitrogen source, titanyl sulfate as the titanium source, copper chloride as the copper source and ammonium hydroxide as the precipitant in an IS-RPB. The particle size of obtained photocatalyst was about 11.40 nm with narrow size-distribution via SEM and TEM. According to XPS, N replaced part of O, and was uniformly dispersed in the TiO2 lattice in the form of interstitial N and substitutional N. Cu replaced part of Ti and existed in the form of Cu2+. The synergistic effect of these two elements forms a new impurity energy level and reduces band gap energy of TiO2 nanoparticles. The specific surface areas of Cu/N-TiO2 are 152.97 m2/g. The influence of the main factors on the degradation rate was studied, the results showed that the removal efficiency could reach 100% under the optimal operating conditions after 2 hours UV light irradiation. The EPR measurement showed that the superoxide radical (O2-·) played a leading role in the degradation process, while the effect of photogenerated holes (h+) and hydroxyl radicals (OH·) were relatively weak.

The cleanup of carbon tetrachloride (CCl4) in groundwater is challenging due to its high volatility and tendency to form a dense nonaqueous liquid phase. From the engineering applications perspective, the pump-and-treat (PAT) technology has substantial advantages owing to its large-scale implementation ability to solve groundwater contamination. However, few studies focused on the variation in chloride contaminants in remediation sites after the contaminated groundwater was pumped and treated. Herein, we monitored the changes in chlorinated contamination in groundwater from 12 aquifers at the field level for 6 months. Considering that the natural attenuation of chlorinated contamination is inseparable from the action of microorganisms, the major environmental factors influencing biodegradation were also evaluated. A redundancy analysis (RDA) showed that inorganic salts (DS, DN, and DF) were the most important factor (>60%) affecting the concentration of chloride contaminants, including the negative correlation between DN and the degradation of contaminants in shallow aquifers. In deep aquifers, DS, DF, and pH explained most of the degradation of chloride contaminants. For bedrock layers, DCl was positively relevant to the chloride contaminants in wells PTJ2 and PTJ10. In addition, EC and DS accounted for 73.2% and 92.4% of the contaminant’s variance in wells PTJ4 and PTJ8, respectively. Moreover, the concentrations of the corresponding contaminations and physicochemical variation in three different depths of aquifers were compared; the shallower aquifers showed a higher biodegradation. The in situ monitoring and analysis of contaminated groundwater in remediation sites under PAT will promote practical wastewater treatment technologies in engineering applications.