Laboratory Evaluation of Performance Recovery of Aged SBS-modified Asphalt Using Regenerants with Different Base Oil Components

In this study,the regenerative effects of different regenerants on aged SBS-modified asphalt from different perspectives were investigated,including their conventional properties,viscoelastic behavior,creep-related properties,and micromorphology.Base oils composed of different proportions of aromatic and saturated hydrocarbons as well as the styrene-butadiene-styrene(SBS)restorer were used to prepare the regenerants.The results showed that the components of the base oil of the regenerant played a crucial role in determining the characteristics and performance of the recycled SBSmodified asphalt.Regenerants containing a high proportion of aromatics dissolved the hard segment in the SBS restorer,thereby delaying the effect of a reduction in the regenerants on the performance of the aged asphalts at a high temperature.Regenerants containing a high proportion of saturates dissolved the soft segment in the SBS restorer to enhance the lowtemperature performance of the recycled asphalts.In addition,the stress sensitivity of the recycled asphalts increased with the fraction of aromatics in the regenerant.As the aromatic content of the base oil components of the regenerants increased and their saturate content decreased,the state of dispersion of the SBS phase in the recycled SBS-modified asphalts improved.The optimal content of aromatics in the base oil of the regenerants should be set in the range of 33%to 47%to ensure the adequate performance of the recycled asphalts and a high efficiency of the SBS restorer.

Simulation of Solvent Extraction for Naphthenic Lubricating Base Oils

Solvent extraction is the process of separating aromatics from vacuum distillates for the production oflubricating base oils. In this study, the authors use dimethyl sulfoxide (DMSO) instead of furfural as solvent, in light of itshigher selectivity, to obtain extracts with a high aromatic content for naphthenic lubricating base oils. We systematicallyinvestigated effects of the solvent-to-oil (S/O) ratio and extraction temperature on the yield of the extract, efficiency ofaromatic removal, and composition of the extracts and raffinates. The results showed that the aromatic content of extractsfor naphthenic oils could reach a high value of about 80%. The solvent maintained a high selectivity for aromatics fornaphthenic oils even under a high S/O ratio and a high extraction temperature. Moreover, the efficiency of aromatic removalfor naphthenic lubricating base oils could be enhanced by increasing either the S/O ratio or the extraction temperature,although these measures had limited effects in practice. Following this, we used the non-random two-liquid (NRTL) modelbased on the pseudo-component approach to simulate the liquid-liquid equilibrium of the system of DMSO + naphtheniclubricating base oils, and determined the parameters of binary interaction through regression based on the data on phaseequilibrium. The modeling results showed that the predicted yield, content of the solvent, and composition of the raffinatesand extracts were in good agreement with those obtained in the experiments. This validates the reliability of the model usedto represent the DMSO + naphthenic lubricating base oil system. Both the experimental data and the method of simulationreported here can help optimize the extraction of naphthenic lubricating base oils, and provide a better understanding of thecorresponding process.

Thermal oxidation of two aviation synthetic lubricant base oils

The thermal degradation of two synthetic lubricants base oils, poly-a-olefins （PAO） and di-esters （DE）, was investigated under oxidative pyrolysis condition and their properties were characterized in simulated ＂areo-engine＂ by comparing the thermal stability and identifying the products of thermal decomposition as a function of exposure temperature. The characterization of the products were performed by means of Fourier transform infrared spectrometry （FTIR）, gas chromatography/mass spectrometry （GC/MS） and viscosity experiments. The results show that PAO has the lower thermal stability, being degraded at 200℃ different from 300 ℃ for DE. Several by-products are identified during the thermal degradation of two lubricant base oils. The majority of PAO products consist of alkenes and olefins, while more oxygen-contained organic compounds are detected in DE samples based on GC/MS analysis. The related reaction mechanisms are discussed based on the experimental results.

The Influence of Paraffinic Base Oil on Low-temperature Viscosity of Naphthenic Base Oil

Low-temperature viscosity of lube oils mixed with paraffinic base oil and naphthenic base oil at different mass ratios has been tested by experiments. The influence of paraffinic base oil on the performance of naphthenic base oil was investigated by studying the low-temperature viscosity of tested oils. The viscosity of lube oils increased with an increasing content of high-viscosity paraffinic base oil in the oil mixture. And the low-temperature viscosity was less influenced when the content of paraffinic base oil in the mixture was insignificant. In order to reduce the cost for formulating lubricating oil, a small fraction of paraffinic base oil can be added into naphthenic base oil as far as the property of lubricating oil can meet the specification. According to the study on low-temperature viscosity of the oil mixed with paraffinic base oil and naphthenic base oil, a basic rule was worked out for the preparation of qualified lubricating oils.

Hydrocracking diversity in n-dodecane isomerization on Pt/ZSM-22 and Pt/ZSM-23 catalysts and their catalytic performance for hydrodewaxing of lube base oil

Nobel metallic Pt/ZSM-22 and Pt/ZSM-23 catalysts were prepared for hydroisomerization of normal dodecane and hydrodewaxing of heavy waxy lube base oil.The hydroisomerization performance of n-dodecane indicated that the Pt/ZSM-23 catalyst preferred to crack the C-C bond near the middle of n-dodecane chain,while the Pt/ZSM-22 catalyst was favorable for breaking the carbon chain near the end of n-dodecane.As a result,more than 2%of light products(gas plus naphtha)and3%more of heavy lube base oil with low-pour point and high viscosity index were produced on Pt/ZSM-22 than those on Pt/ZSM-23 while using the heavy waxy vacuum distillate oil as feedstock.

Production of Quality Hydrogenated Base Oils through Isodewaxing Technology

This article presents the successful experience in adopting the Isodewaxing technology in the lube oil unit of Shanghai Gaoqiao refinery. In line with the demand of different crude slate for different reaction depth, and good match between the optimal product quality and the yield, the refinery has make strenuous efforts to optimize the operation and reduce the energy consumption to manufacture high-quality hydrogenated base stocks.

Coal Tar Derived Metallocene Catalyst for Polymerization of 1-Decene into Low-viscosity Poly-α-Olefin Lubricating Base Oil

The production of poly-α-olefins(PAOs)has attracted attention due to their excellent viscosity-temperature dependence,wear characteristics,oxidative properties,and high thermal stability.In this study,indene extracted during coal tar refining was used as a raw material to synthesize a bis(indenyl)zirconium dichloride metallocene catalyst.A PAO with low viscosity and a high viscosity index was produced via the oligomerization of 1-decene in the presence of both the prepared metallocene and a methylaluminoxane(MAO)co-catalyst.Notably,the effects of different synthesis reaction parameters,such as Al:Zr ratio,amount of catalyst,and reaction temperature,on the conversion ratio and product selectivity were investigated in detail.The produced PAO was thoroughly characterized using Fourier-transform infrared,^(13)C,and^(1)H nuclear magnetic resonance spectroscopies;gas chromatography;and viscosity measurements.At 70℃,the metallocene catalyst created more stable active sites.In addition,the alkylation effect of MAO was noticeable.Interestingly,the obtained catalysis results demonstrated that a high conversion ratio of~93%was achieved at a low reaction temperature of 70℃,with a catalyst dosage of 0.0848 mmol and Al:Zr ratio of 8.48mmol:0.0848mmol.Moreover,under these optimal conditions,the kinematic viscosity of PAO was 4.25 mm2/s at 100℃,and the viscosity index was 139,indicating good viscosity-temperature properties.

Influence of Different Hydrocarbon Molecules on Physical Properties of Mineral Base Oils

Different kinds of base oils with different viscosity were analyzed in this paper, including eight mineral base oils, alkylnaphthalene and three synthetic PAO oils. The influence of different hydrocarbon molecules on physical properties of mineral base oils was investigated, such as density(d), kinematic viscosity(KV), viscosity index(VI), etc. Possible reasons for some inconsistent phenomena in data processing were also theoretically analyzed in detail. The refractive indexes(RI), d and molecular weight(M) decrease linearly with the increase of paraffinic content other than KV, which declines exponentially. There are no clear relationships between physical properties of base oils and naphthenic content while polycyclic alkanes show a strong correlation with M and KV. The influence of aromatics on physical properties of base oils is just the opposite of paraffin's. VI of the base oils with low aromatics content increases linearly as their paraffinic contents rise when their carbon numbers are approximately equal. However, base oils with high aromatics content follow an utterly different rule, in which VI declines dramatically linearly with the increase in polycyclic aromatic content, which is the essential reason why naphthenic base oils all have terrible viscosity-temperature characteristics while paraffinic base oils usually do not.

Modification of methyl oleate for silicon-based biological lubricating base oil

A new kind of silicon-based biological lubricating base oil with good viscosity-temperature behavior,viscosity index,thermostability,oxidation stability and wear resistance performance was synthesized as a derivative of methyl oleate.Trimethylsilylation reaction was introduced to further improve methyl oleate oxidation stability and lubricity after epoxidation and open-ring reactions.The order of effectiveness of acid binding agent was N,N-diisopropylethylamine(DIEA) > pyridine > diethylamine > triethylamine,and the effects of various parameters on the trimethylsilylation reaction as well as on the silicon-oxygen bond stability and reaction yield were studied.A maximum yield of 34.54%was achieved at hydroxyl/trimethyl chlorosilane/DIEA molar ratio of1:1.25:1,reaction temperature 40℃,reaction time 1.5 h.

Inverse Gas Chromatographic Study of the Oxidation Stability of Lubricating Base Oils via Solubility Parameter Calculations

The Flory-Huggins interaction parameter(χ1,2∞) and solubility parameter(δ2) and its hydrogen bonding sensing component(δh) were determined using inverse gas chromatography(IGC).These parameters were successfully used in the probes of chemical changes that occur during the oxidation of naphthenic and paraffinic base oils in a GC column.Changes in χ1,2∞ values reflect the different types of intermolecular interactions(dispersive,polar,hydrogen bonding) of the given lubricating base oil during oxidation.The obtained results showed that δh component of solubility parameter is the most important parameter for probing the oxidative-chemical changes during the oxidation of given lubricating oils.

The Role of Diesel Soot in the Tribological Behavior of 150SN Base Oil

The diesel soot was collected from diesel engine exhaust pipe. The morphology and structure of the collected diesel soot was characterized by HRTEM, XRD and XPS and its tribological behavior was investigated by a SRV IV oscillating reciprocating friction and wear tester. Test results showed that the tribological behavior of diesel soot was largely influenced by the test load. Under a low load, the diesel soot could reduce the wear volume of the disc. While under a high load, the diesel soot could reduce the friction coefficient of base oil. Based on the characterization of the worn scars by the SEM technique, the 3D surface profiler and the Raman spectroscopy, it was assumed that the core-shell structure of diesel soot with several graphitic layers played important roles. On one hand, its spherical and special structure could make it roll between friction pairs to reduce wear under a low load. On the other hand, its outer-shell graphite layers could be peeled off to form lubrication film to reduce friction under a high load and shear force.

Interaction of Chloroprene and Nitrile-Butadiene Rubber with Lubricating Greases and Base Oils

The present communication addresses compatibility of two synthetic rubber types,chloroprene and nitrile-butadiene ones,with a number of base oils of petroleum origin and lubricating greases produced thereof.Four base oils,including three naphthenic products with varying degrees of refining and one paraffinic product,were compared with each other in terms of their effect on the rubbers.Degenerative changes occurring in the rubbers on contact with the oils and greases were studied using accelerated ageing tests.Alterations in rubber parameters,such as hardness,weight and glass transition temperature,caused by interaction with oil were monitored.The main physicochemical mechanisms standing behind the changes observed in the rubber properties were found to be(i) migration of plasticizer from rubber into the oil phase,(ii) absorption of oil by rubber,and(iii) oxidation of rubber.An increase in glass transition temperature(Tg) of rubber aged in a base oil or grease was considered as an indirect indication that the plasticizer had migrated out of rubber;the plasticizer accumulation in the oil phase being directly confirmed by gas chromatography.In order to suppress the plasticizer migration,oil additivation with dioctyl adipate(DOA),a common plasticizer used in rubber formulations,was attempted.However,the DOA-additivated oils,while reducing plasticizer migration,were found to cause more swelling than the original oils in the case of chloroprene rubber.As an alternative,replacement of DOA by an alkylated aryl phosphate in nitrile-butadiene rubber formulations was considered,but it did not solve the problem either.The results of this study suggest conclusively that the type of rubber,the plasticizer,and the base oil are all the crucial parameters that should be considered when matching rubber with oil in real-life applications.Interaction of rubber with base oils and with greases produced thereof is largely controlled by(i) solvency of the base oils and(ii) polarity and cross-linking density of the rubber matrix.Higher temperatures accelerate ageing in all cases.

Prediction of Lubricant Physicochemical Properties Based on Gaussian Copula Data Expansion

The composition of base oils affects the performance of lubricants made from them.This paper proposes a hybrid model based on gradient-boosted decision tree(GBDT)to analyze the effect of different ratios of KN4010,PAO40,and PriEco3000 component in a composite base oil system on the performance of lubricants.The study was conducted under small laboratory sample conditions,and a data expansion method using the Gaussian Copula function was proposed to improve the prediction ability of the hybrid model.The study also compared four optimization algorithms,sticky mushroom algorithm(SMA),genetic algorithm(GA),whale optimization algorithm(WOA),and seagull optimization algorithm(SOA),to predict the kinematic viscosity at 40℃,kinematic viscosity at 100℃,viscosity index,and oxidation induction time performance of the lubricant.The results showed that the Gaussian Copula function data expansion method improved the prediction ability of the hybrid model in the case of small samples.The SOA-GBDT hybrid model had the fastest convergence speed for the samples and the best prediction effect,with determination coefficients(R^(2))for the four indicators of lubricants reaching 0.98,0.99,0.96 and 0.96,respectively.Thus,this model can significantly reduce the model’s prediction error and has good prediction ability.

Oil Saturation Is Determined by Different Experimental Methods

Oil saturation was an important parameter of reservoir evaluation, which had important guiding significance for oilfield development. In this paper, the oil saturation of tight oil in G area was studied, and the original oil saturation of the study area was studied by using the comprehensive experimental method. The original oil saturation of tight oil in the study area was determined by J function method, rock electricity method and oil-based mud coring method. The results showed that through the comparison of three experimental methods, it could be concluded that the J function method leads to the low value of oil saturation in the study area. The oil-based mud coring method was more suitable for the determination of oil saturation in this area than the other two methods because it needs to meet too many conditions and the calculation results were also low. G area was located in Qili Village, Ordos Basin.

Grinding temperature and energy ratio coefficient in MQL grinding of high-temperature nickel-base alloy by using different vegetable oils as base oil

Vegetable oil can be used as a base oil in minimal quantity of lubrication (MQL). This study compared the performances of MQL grinding by using castor oil, soybean oil, rapeseed oil, corn oil, sunflower oil, peanut oil, and palm oil as base oils. A K-P36 numerical-control precision surface grinder was used to perform plain grinding on a workpiece material with a high-temperature nickel base alloy. A YDM-III 99 three-dimensional dynamometer was used to measure grinding force, and a clip-type thermocouple was used to determine grinding temperature. The grinding force, grinding temperature, and energy ratio coefficient of MQL grinding were compared among the seven vegetable oil types. Results revealed that (1) castor oil-based MQL grinding yields the lowest grinding force but exhibits the highest grinding temperature and energy ratio coefficient; (2) palm oil-based MQL grinding generates the second lowest grinding force but shows the lowest grinding temperature and energy ratio coefficient; (3) MQL grinding based on the five other vegetable oils produces similar grinding forces, grinding temperatures, and energy ratio coefficients, with values ranging between those of castor oil and palm oil; (4) viscosity significantly influences grinding force and grinding temperature to a greater extent than fatty acid varieties and contents in vegetable oils; (5) although more viscous vegetable oil exhibits greater lubrication and significantly lower grinding force than less viscous vegetable oil, high viscosity reduces the heat exchange capability of vegetable oil and thus yields a high grinding temperature; (6) saturated fatty acid is a more efficient lubricant than unsaturated fatty acid; and (7) a short carbon chain transfers heat more effectively than a long carbon chain. Palm oil is the optimum base oil of MQL grinding, and this base oil yields 26.98 N tangential grinding force, 87.10 N normal grinding force, 119.6 degrees C grinding temperature, and 42.7% energy ratio coefficient. (C) 2015 The Authors. Production and hosting by Elsevier Ltd. on behalf of Chinese Society of Aeronautics and Astronautics.

Tribological Properties of Few-layer Graphene Oxide Sheets as Oil-Based Lubricant Additives

The performance of a lubricant largely depends on the additives it involves. However, currently used additives cause severe pollution if they are burned and exhausted. Therefore, it is necessary to develop a new generation of green additives. Graphene oxide（GO） consists of only C, H and O and thus is considered to be environmentally friendly. So the tribological properties of the few-layer GO sheet as an additive in hydrocarbon base oil are investigated systematically. It is found that, with the addition of GO sheets, both the coefficient of friction（COF） and wear are decreased and the working temperature range of the lubricant is expanded in the positive direction. Moreover, GO sheets has better performance under higher sliding speed and the optimized concentration of GO sheets is determined to be 0.5wt%. After rubbing, GO is detected on the wear scars through Raman spectroscopy. And it is believed that, during the rubbing, GO sheets adhere to the sliding surfaces, behaving like protective films and preventing the sliding surfaces from contacting with each other directly. This paper proves that the GO sheet is an effective lubricant additive, illuminates the lubrication mechanism, and provides some critical parameters for the practical application of GO sheets in lubrication.

Preparation and Characterization of Multiester Derivative from Plant Oil as Base Stock for Biolubricants

As an alternative to petroleum-based lubricants, which are harmful to the environment in excessive amounts, a biodegradable multiester derivative(OFANE) was obtained from plant oil through a chemical modification process with four steps as follows: hydrolysis, esterification, epoxidation, and ring-opening reaction. The physical and chemical properties of OFANE, such as viscosity, acid value, pour point, evaporation loss, and oxidation induction time were measured. Results showed that OFANE had good low-temperature fluidity, thermal-oxidative stability, and tribological properties. The tribological properties of OFANE with dimeric acid additive were evaluated. The final biodegradation experiment indicated that OFANE had excellent biodegradability. The prepared OFANE showed great potential as substitute for petroleum-based lubricating base oils.

Reviews on Transformer Oil-based Nanofluids

目前纳米改性变压器油由于其高散热性和独特的电气性能,正受到越来越广泛的关注。以近年来纳米改性变压器油的相关研究成果为基础,分析了纳米改性变压器油在导热、击穿、老化、抗水分影响以及改性油-纸相互作用等方面的特点,并介绍了目前常用的3种用于解释绝缘油介质中纳米颗粒改性机理的理论模型,最后提出了纳米改性变压器油领域后续研究需要关注的问题,即纳米颗粒材料体系的选择、高稳定性改性变压器油的制备工艺以及纳米颗粒对变压器油的改性机理。

Gas-hydrate formation,agglomeration and inhibition in oil-based drilling fluids for deep-water drilling

One of the main challenges in deep-water drilling is gas-hydrate plugs,which make the drilling unsafe.Some oil-based drilling fluids（OBDF） that would be used for deep-water drilling in the South China Sea were tested to investigate the characteristics of gas-hydrate formation,agglomeration and inhibition by an experimental system under the temperature of 4 ？C and pressure of 20 MPa,which would be similar to the case of 2000 m water depth.The results validate the hydrate shell formation model and show that the water cut can greatly influence hydrate formation and agglomeration behaviors in the OBDF.The oleophobic effect enhanced by hydrate shell formation which weakens or destroys the interfacial films effect and the hydrophilic effect are the dominant agglomeration mechanism of hydrate particles.The formation of gas hydrates in OBDF is easier and quicker than in water-based drilling fluids in deep-water conditions of low temperature and high pressure because the former is a W/O dispersive emulsion which means much more gas-water interfaces and nucleation sites than the later.Higher ethylene glycol concentrations can inhibit the formation of gas hydrates and to some extent also act as an anti-agglomerant to inhibit hydrates agglomeration in the OBDF.

Synthesis of melamine-formaldehyde microcapsules containing oil-based fragrances via intermediate polyacrylate bridging layers

A general and versatile strategy to prepare melamine-formaldehyde(MF)microcapsules encapsulating oil-based fragrances by combining solvent evaporation and in situ polymerization was proposed in this work.The oil-based fragrance was pre-encapsulated by an inner polyacrylate membrane via solvent evaporation,followed by in situ polymerization of MF precondensates as an outer shell.The polyacrylate membrane is used as an intermediate bridging layer to stabilize the oil-based fragrance,and to provide driving forces for in situ polymerization of MF precondensates through electrostatic attractions between carboxyl groups and ammonium ions.It was demonstrated that MF microcapsules containing clove oil were prepared successfully.The amount and the composition of the intermediate polyacrylate bridging layer were critical.Smooth and sphere-shaped MF-clove oil microcapsules were prepared when the weight ratio of polyacrylate to clove oil was over 60 wt%and the concentration of acrylic acid(AA)increased to 10 wt%in polyacrylate.In addition,MF microcapsules containing sunflower oil and hexyl salicylate were prepared by using this method.The work suggests that this new approach can be potentially used to encapsulate various core materials,tuning the shell properties of microcapsules such as thickness,mechanical strength and release properties.