Removal of Nitrogen Compounds from Fuels by Deep Eutectic Solvent Based on 1-Butyl-3-Methylimidazolium Bromide and Dicarboxylic Acids

1-Butyl-3-methylimidazolium bromide-based ([Bmim]Br-based) deep eutectic solvents (DESs) can be used aseffective extractants for removing nitrogen compounds from fuel oil. Among the DESs studied, the combination of [Bmim]Brand malonic acid (MA) in a 1:1 molar ratio demonstrated good performance for the removal of both basic and non-basic Ncompounds. The DES [Bmim]Br-MA exhibited extraction efficiencies of 98.4% for quinoline and 92.9% for indole after 30min at 30 ℃ with a DES/oil mass ratio of 1/7. Moreover, the extraction efficiencies remained high at 86.4% for quinolineand 85.9% for indole after recycling the DES four times.. In addition, the DES [Bmim]Br-MA could effectively removeN compounds from Fushun shale diesel oil, with extraction efficiencies of 83.5% for total nitrogen and 89.9% for basicnitrogen at a DES/oil mass ratio of 1/1.

Importance of V^(4)and optimal acid environment in the hydroxylation of inert benzene via activation of C_(sp2)-H bond

Hydroxylation of inert benzene through the activation of the C_(sp2)-H bond is a representative reaction about the transformation of C-H bonds to C-O bonds,which has far-reaching guiding significance but remains a challenging scientific problem.To overcome this problem,a series of VOx-Ga_(2)O_(3)/SiO_(2)-Al_(2)O_(3)were prepared to achieve an efficient and economical hydroxylation path of benzene to phenol.The results showed that the phenol yield was 72.89%(selectivity>98.1%)under the optimum conditions.The reason is that the C-H bond in the benzene ring is activated by heterolysis over a VOx-Ga_(2)O_(3)/SiO_(2)-Al_(2)O_(3)catalyst.Meanwhile,the introduction of aluminum(Al)and gallium(Ga)made a qualitative change in the catalyst,enhancing the electron motion and spin motion of vanadium species,resulting in the increase of V4^(+)/V5^(+)ratio.In addition,the catalyst can provide an optimal acidic environment and a threedimensional cross-linked surface structure that facilitates product diffusion.

Comprehensive understanding of the thriving electrocatalytic nitrate/nitrite reduction to ammonia under ambient conditions

Ammonia(NH_(3))is a multifunctional compound that is an important feedstock for the agricultural and pharmaceutical industries and attractive energy storage medium.At present,NH_(3)synthesis is highly dependent on the conventional Haber–Bosch process that operates under harsh conditions,which consumes large quantities of fossil fuels and releases a large amount of carbon dioxide.As an alternative,electrosynthesis is a prospective method for producing NH_(3)under normal temperature and pressure conditions.Although electrocatalytic nitrogen reduction to ammonia has attracted considerable attentions,the low solubility of N_(2)and high N≡N cracking energy render the achievements of high NH_(3) yield rate and Faradaic efficiency difficult.Nitrate and nitrite(NO_(x)^(-))are common N-containing pollutants.Due to their high solubilities and low dissociation energy of N=O,NO_(x)^(-)−are ideal raw materials for NH_(3) production.Therefore,electrocatalytic NO_(x)^(-)−reduction to NH_(3)(eNO_(x)RR)is a prospective strategy to simultaneously realise environmental protection and NH_(3) synthesis.This review offers a comprehensive understanding of the thriving eNO_(x)RR under ambient conditions.At first,the popular theory and mechanism of eNO_(x)RR and a summary of the measurement system and evaluation criteria are introduced.Thereafter,various strategies for developing NO_(x)−reduction catalysts are systematically presented and discussed.Finally,the challenges and possible prospects of electrocatalytic NO_(x)^(-1) reduction are outlined to facilitate energy-saving and environmentally friendly large-scale synthesis of NH_(3) in the future.

Filtration performance and modeling of granular bed for dust removal from coal pyrolytic vapors

Dust removal from pyrolytic vapors at high temperatures is an obstacle to the industrialization of the coal pyrolysis process.In this work,a granular bed with expanded perlites as filtration media was designed and integrated into a 10 t·d^(–1)coal pyrolysis facility.The testing results showed that around 97.56%dust collection efficiency was achieved.As a result,dust content in tar was significantly lowered.The pressure drop of the granular bed maintained in the range of 356 Pa to 489 Pa.The dust size in the effluent after filtration exhibited a bimodal distribution,which was attributed to the heterogeneity of the dust components.The effects of filtration bed on pyrolytic product yields were also discussed.A modified filtration model based on the macroscopic phenomenological theory was proposed to describe the performance of the granular bed.The computation results were well agreed with the experimental data.

Regulation of interlayer channels of graphene oxide nanosheets in ultra-thin Pebax mixed-matrix membranes for CO_(2) capture

For the application of carbon capture by membrane process,it is crucial to develop a highly permeable CO_(2)-selective membrane.In this work,we reported an ultra-thin polyether-block-amide(Pebax)mixedmatrix membranes(MMMs)incorporated by graphene oxide(GO),in which the interlayer channels were regulated to optimize the CO_(2)/N_(2) separation performance.Various membrane preparation conditions were systematically investigated on the influence of the membrane structure and separation performance,including the lateral size of GO nanosheets,GO loading,thermal reduction temperature,and time.The results demonstrated that the precisely regulated interlayer channel of GO nanosheets can rapidly provide CO_(2)-selective transport channels due to the synergetic effects of size sieving and preferential adsorption.The GO/Pebax ultra-thin MMMs exhibited CO_(2)/N_(2) selectivity of 72 and CO_(2) permeance of 400 GPU(1 GPU=106 cm^(3)(STP)·cm^(2)·s^(-1)·cmHg^(-1)),providing a promising candidate for CO_(2) capture.

Oxidative Desulfurization of Fuel Oil with H_(3)PO_(4)-based Deep Eutectic Solvents

A series of Lewis-acid deep eutectic solvents (DESs) were synthesized by stirring phosphoric acid and zincchloride as raw materials at 80℃ to form H_(3)PO_(4)/nZnCl_(2) (n = 0.1, 0.25, 0.5, 0.75, 1). The DESs were characterized byFourier transform infrared spectrophotometry (FT-IR), thermogravimetry/differential thermogravimetry (TG/DTG), andelectron spray ionization mass spectrometry (ESI-MS). The DESs were used as both extractants and catalysts to removedibenzothiophene from fuels via oxidative desulfurization (ODS). Experiments were performed to investigated the influenceof factors such as composition of DES, temperature, oxidant dosage (molar ratio of O:S), DES dosage (volume ratio ofDES:oil), and number of cycles on desulfurization rate. The results indicated that the removal rate of dibenzothiophene (DBT)was affected by the Lewis acidic DESs, with that of H_(3)PO_(4)/0.25∙ZnCl_(2) reaching 96.4% under optimal conditions (Voil=5 mL,VDES=1 mL, an oxidant dosage of 6, T=50 ℃). After six cycles, the desulfurization rate of H_(3)PO_(4)/0.25∙ZnCl_(2) remained above94.1%. The apparent activation energy of dibenzothiophene (DBT) removal reaction was determined by a pseudo-first orderkinetic equation according to the Arrhenius equation to be 32.34 kJ/mol, as estimated. A reaction mechanism is proposedbased on the experimental data and characterization results.

Numerical Simulation of Wet Particles Motion in a Vertical Powder Dryer

In this study,the motion of wet particles in the drying unit of a vertical powder dryer is investigated by using a Discrete element method(DEM)coupled with a liquid bridge force.In particular,by varying parameters such as the particle mass flow rates,the superficial gas velocities,and superficial gas temperatures,the influence of the moisture content on the flow behavior is examined.The results show that when the moisture content increases,the mean particle velocity decreases while the bed mean solid“holdup”and the mean residence time(MRT)of particles grow.It is also found that the local solid holdup is relatively higher in the near-wall region and decreases towards the near-fluid region.Two regression models are introduced accordingly for the mean particle velocity and the bed mean solid holdup by means of the RSM-BBD(Response surface methodology-Box-Behnken design)method to obtain the optimal combination of parameters for flooding prevention.Finally,the optimal results are compared with numerical observations.As the relative error is less than 10%,this demonstrates that the proposed methodology can accurately describe the particle flow dynamics in the drying unit.

Photocatalytic Oxidative Desulfurization of Dibenzothiophene on TiO2 Modified Bimodal Mesoporous Silica

By using the bimodal mesoporous silica(BMMS) as the carrier and butyl titanate as the titanium source, the TiO_2/BMMS catalyst was prepared. The samples were characterized by XRD, XRF, N_2 adsorption and desorption, FTIR, UVvis,SEM, EDS, and TEM techniques. The test results showed that TiO_2 was amorphous, the TiO_2/BMMS catalyst had an ordered bimodal mesoporous structure, and the chemical interaction existed between BMMS and TiO_2. Since the TiO_2/BMMS had a lower band gap, its photocatalytic activity was better than TiO_2. Under UV irradiation a one-pot PODS system was set up, using TiO_2/BMMS as the catalyst, H_2O_2 as the oxidant, and methanol as the solvent. The TiO_2/BMMS catalyst showed better photocatalytic activity than the mono-modal mesoporous TiO_2/SBA-15 catalyst, and the desulfurization rate of dibenzothiophene(DBT) over TiO_2/BMMS catalyst could reach 99._2%. The TiO_2/BMMS catalyst also had so good stability that the desulfurization rate of DBT did not drop apparently after 8 cycles of reusing, and could still be close to 90%.

Structural characteristics and high-temperature tribological behaviors of laser cladded NiCoCrAlY−B_(4)C composite coatings on Ti6Al4V alloy

In order to improve the hardness and tribological performance of Ti6Al4V alloy,NiCoCrAlY-B_(4)C composite coatings with B_(4)C of 5%,10%and 15%(mass fraction)were fabricated on its surface by laser cladding(LC).The morphologies,chemical compositions and phases of obtained coatings were analyzed using scanning electronic microscope(SEM),energy dispersive spectrometer(EDS),and X-ray diffraction(XRD),respectively.The effects of B_(4)C mass fraction on the coefficient of friction(COF)and wear rate of NiCoCrAlY-B_(4)C coatings were investigated using a ball-on-disc wear tester.The results show that the NiCoCrAlY-B_(4)C coatings with different B_(4)C mass fractions are mainly composed of NiTi,NiTi_(2),α-Ti,CoO,AlB_(2),TiC,TiB and TiB_(2)phases.The COFs and wear rates of NiCoCrAlY-B_(4)C coatings decrease with the increase of B_(4)C content,which are contributed to the improvement of coating hardness by the B_(4)C addition.The wear mechanisms of NiCoCrAlY-B_(4)C coatings are changed from adhesive wear and oxidation wear to fatigue wear with the increase of B_(4)C content.

Preparation of amidoxime-based PE/PP fibers for extraction of uranium from aqueous solution

A novel amidoxime-based fibrous adsorbent,denoted as PE/PP-g-(PAAc-co-PAO), was prepared by preirradiation grafting of acrylic acid and acrylonitrile onto polyethylene-coated polypropylene skin-core(PE/PP)fibers using 60 Co γ-ray irradiation, followed by amidoximation. The original and modified PE/PP fibers were characterized by a series of characterization methods to demonstrate the attachment of amidoxime groups onto the PE/PP fibers. Breaking strength tests confirmed that the fibrous adsorbent could maintain good mechanical properties. The adsorption capacity of the PE/PP-g-(PAAc-coPAO) fibers was investigated in simulated seawater with an initial uranium concentration of 330 μg/L. The uranium adsorption capacity was 2.27 mg/g-adsorbent after 24 h in simulated seawater, and the equilibrium data were well described by the Freundlich isotherm model. The PE/PP-g-(PAAc-co-PAO) adsorbent exhibited good regeneration and recyclability during five adsorption-desorption cycles.The adsorption test was also performed in simulated radioactive effluents with uranium concentrations of 10 and100 μg/L. The effect of the pH value on the adsorption capacity was also studied. At a very low initial concentration 10 μg/L solution, the PE/PP-g-(PAAc-co-PAO)fiber could remove as much as 93.0% of the uranium, and up to 71.2% of the uranium in the simulated radioactive effluent. These results indicated that the PE/PP-g-(PAAcco-PAO) adsorbent could be used in radioactive effluents over a wide range of pH values. Therefore, the PE/PP-g-(PAAc-co-PAO) fibers, with their high uranium selectivity,good regeneration and recyclability,good mechanical properties, and low cost, are promising adsorbents for extracting uranium from aqueous solutions.

Synthesis of Bimodal Mesoporous TiO_(2)-PTA/BMMS and Its Enhanced Performance in the Photocatalytic Oxidative Desulfurization

With the bimodal mesoporous silica(BMMS)acting as the support and the composite of TiO2 with phosphotungstic acid(PTA)functioning as the active constituent,TiO_(2)-PTA/BMMS was synthesized by the two-step impregnation route.This catalyst was applied in the photocatalytic oxidative desulfurization(PODS)process,with dibenzothiophene serving as the model sulfur compound.PODS proceeds in one pot,in which H_(2)O_(2) acts as the oxidant and methanol plays the role of the solvent.TiO_(2)-PTA/BMMS was characterized by XRD,N_(2) adsorption and desorption,XRF,FTIR,UV-vis,SEM,EDS and TEM techniques.It showed that the introduction of PTA contributes higher order,higher surface area and pore volume to the bimodal mesoporous support.With TiO_(2)-PTA/BMMS used as the catalyst under the UV irradiation,the desulfurization rate can reach 99.6%.This result is obviously higher than that achieved by TiO_(2)/BMMS.The catalyst also has no significant drop in catalytic activity after eight runs of reusing.In such catalytic system,the synergistic effects of this photocatalytic oxidation and the extraction with the methanol serving as the solvent played an indispensable role.

Secondary Crystallization of Na_2CO_3-Modified HZSM-5 Zeolites with Tetrapropylammonium Hydroxide and Their Catalytic Performance in Thiophene Alkylation Reaction

The Na2CO3-modified HZSM-5 zeolites were further treated by tetrapropylammonium hydroxide(TPAOH) solution. The effect of TPAOH concentration on the secondary crystallization process was investigated. The resulting samples were characterized by a complementary combination of X-ray diffraction, N2 adsorption/desorption, scanning electron microscopy, X-ray fluorescence spectroscopy, XPS, 27 Al and 29 Si magic-angle spinning nuclear magnetic resonance spectroscopy, BET and temperature-programmed desorption techniques. The results showed that the secondary crystallization of the HZSM-5 zeolite could result in migration of non-framework species from the internal channels to the zeolite surface and their transformation into framework species. The catalytic activity of these modified samples for thiophene alkylation was evaluated. Both the activity and stability of the catalysts were improved after secondary crystallization.

Facile synthesis of Fe-containing graphitic carbon nitride materials and their catalytic application in direct hydroxylation of benzene to phenol

Fe-containing graphitic carbon nitride（Fe-g-C3N4） materials were synthesized via one-step pyroly-sis of FeCl3 and dicyandiamide. The physicochemical properties of the synthesized Fe-g-C3N4 sam-ples were characterized by N2 adsorption-desorption, X-ray diffraction, thermal gravimetric, Fourier transform infrared, UV-vis diffuse reflectance, X-ray photoelectron spectroscopy, and transmission electron microscopy. The Fe cations were anchored by nitrogen-rich g-C3N4, whereas the graphitic structures of g-C3N4 were retained after the introduction of Fe. As heterogeneous catalysts, Fe-g-C3 N4 exhibited good catalytic activity in the direct hydroxylation of benzene to phenol with H2O2, affording a maximum yield of phenol of up to 17.5%. Compared with other Fe- and V-containing g-C3N4 materials, Fe-g-C3N4 features a more convenient preparation procedure and higher catalytic productivity of phenol.

Progress and Prospects of Hydrogen Production: Opportunities and Challenges

This study presents an overview of the current status of hydrogen production in relation to the global requirement for energy and resources.Subsequently,it symmetrically outlines the advantages and disadvantages of various production routes including fossil fuel/biomass conversion,water electrolysis,microbial fermentation,and photocatalysis(PC),in terms of their technologies,economy,energy consumption,and costs.Considering the characteristics of hydrogen energy and the current infrastructure issues,it highlights that onsite production is indispensable and convenient for some special occasions.Finally,it briefly summarizes the current industrialization situation and presents future development and research directions,such as theoretical research strengthening,renewable raw material development,process coupling,and sustainable energy use.

Copper methanesulfonate-acetic acid as a novel catalytic system for tetrahydropyranylation of alcohols and phenols

A synergistic catalytic effect between copper methanesulfonate and acetic acid in tetrahydropyranylation of alcohols and phenol at room temperature under solvent free condition has been described. Both alcohols （primary, secondary and tertiary） and phenols reacted with 3,4-dihydro-2H-pyran smoothly to afford the corresponding tetrahydropyranyl ethers in good yields.

Purification of Crude Glycerol from Waste Cooking Oil Based Biodiesel Production by Orthogonal Test Method

Purification of original crude glycerol obtained from biodiesel production was conducted in a laboratory scale equipment by means of a combined chemical and physical treatment method based upon repeated cycles of acidification of liquid phase to the desired pH value by using 5.85% H3PO4 solution for pH value adjustment, and the mixture was kept at 70 ℃ for 60 rain to make phase separation for obtaining a glycerol-rich middle phase. The yield of crude glycerol reached 81.2%. Subsequently, upon reaction of the obtained glycerol phase with 0.03% of sodium oxalate at 80 ℃ for 30 min the impurity removal rate was equal to 19.8%. The fraction boiling between 164 ℃ and 200 ℃ was collected by vacuum distil- lation followed by decolorization with 2% of active carbon at 80 ℃ for two times to yield the product glycerol with an ac- ceptable purity of 98.10%.

A liquid loading prediction method of gas pipeline based on machine learning

The liquid loading is one of the most frequently encountered phenomena in the transportation of gas pipeline,reducing the transmission efficiency and threatening the flow assurance.However,most of the traditional mechanism models are semi-empirical models,and have to be resolved under different working conditions with complex calculation process.The development of big data technology and artificial intelligence provides the possibility to establish data-driven models.This paper aims to establish a liquid loading prediction model for natural gas pipeline with high generalization ability based on machine learning.First,according to the characteristics of actual gas pipeline,a variety of reasonable combinations of working conditions such as different gas velocity,pipe diameters,water contents and outlet pressures were set,and multiple undulating pipeline topography with different elevation differences was established.Then a large number of simulations were performed by simulator OLGA to obtain the data required for machine learning.After data preprocessing,six supervised learning algorithms,including support vector machine(SVM),decision tree(DT),random forest(RF),artificial neural network(ANN),plain Bayesian classification(NBC),and K nearest neighbor algorithm(KNN),were compared to evaluate the performance of liquid loading prediction.Finally,the RF and KNN with better performance were selected for parameter tuning and then used to the actual pipeline for liquid loading location prediction.Compared with OLGA simulation,the established data-driven model not only improves calculation efficiency and reduces workload,but also can provide technical support for gas pipeline flow assurance.

Determination of the Structure of Polyacrylamide/Aluminum Citrate Colloidal Dispersion Gel System

1 INTRODUCTIONIn recent years,colloidal dispersion gel(CDG)have been attracting more and more in thefield of enhanced oil recovery on account of the cost-effectiveness and high efficiency ofblocking formation.Compared with bulk gel(BG),CDG exhibits lower polymer concentra-tion,undefined shape and selective blocking formation characteristics.The characteris-tics of CDG and BG are related to structure.In the bulk gel a continuous network of polymermolecules is formed predominant through intermolecular cross-linkages.The

Controlling factors of high-quality volcanic reservoirs of Yingcheng Formation in the Songnan gas field

Predicting high-quality volcanic reservoirs is one of the key issues for oil and gas exploration in the Songnan gas field.Core,seismic,and measurement data were used to study the lithologies,facies,reservoir porosity,and reservoir types of the volcanic rocks in the Songnan gas field.The primary controlling factors and characteristics of the high-quality volcanic reservoirs of the Yingcheng Formation in the Songnan gas field were investigated,including the volcanic eruptive stage,edifice,edifice facies,cooling unit,lithology,facies,and diagenesis.Stages with more volatile content can form more high-quality reservoirs.The effusive rhyolite,explosive tuff,and tuff lava that formed in the crater,near-crater,and proximal facies and in the high-volatility cooling units of large acidic-lava volcanic edifices are the most favorable locations for the development of the high-quality reservoirs in the Songnan gas field.Diagenesis dissolution,which is controlled by tectonic action,can increase the size of secondary pores in reservoirs.Studying the controlling factors of the high-quality reservoirs can provide a theoretical basis for the prediction and analysis of high-quality volcanic reservoirs.

Synthetic Process of Bio-Based Phenol Formaldehyde Adhesive Derived from Demethylated Wheat Straw Alkali Lignin and Its Curing Behavior

Lignin is a natural biopolymer with a complex three-dimensional network, commercially obtained from wasteliquid of paper pulp and bioethanol production, and could be a candidate for preparation of environment-friendlybio-based polyphenol material. In the present work, the demethylated wheat straw alkali lignin (D-Lig), preparedby demethylation of wheat straw alkali lignin (Lig) using an in-situ generated Lewis acid, was used to synthesizebio-based phenol formaldehyde resin adhesive (D-LPF) applied in plywood. Effects of synthetic process’s factors,including lignin substitution for phenol, NaOH concentration and molar ratio of formaldehyde to phenol, on thebonding strength and free formaldehyde content of D-LPF were investigated in detail, and the optimum syntheticprocess of D-LPF was obtained as following: Lignin substitution for phenol 60%, NaOH concentration 5.0% andmolar ratio of formaldehyde to phenol 2.0, and under the optimum reaction condition, the D-LPF presented lower free formaldehyde content (0.18%) and higher bonding strength (2.19 MPa), which was better than those ofcontaining-lignin phenol formaldehyde resin adhesive (LPF). Additionally, the curing behavior of the adhesivewas studied by differential scanning calorimetry (DSC) combined with gel time. It can be obtained that D-LPFresin adhesive had the shortest gel time, and fastest curing rate, compared with those of PF and L-PF resin adhesives. The curing kinetics data was fitted well by Kissinger model using non-isothermal DSC method, and theaverage activation energy value was 85.3 kJ/mol, slightly higher than that of commercial PF resin, while lowerthan that of LPF (90.2 kJ/mol). Finally, based on the analytical results of high temperature fourier transform infrared spectroscopy (FTIR), a possible curing mechanism of D-LPF was proposed.