Engineering property test of kaolin clay contaminated by diesel oil

Engineering property of kaolin clay contaminated by diesel oil was studied through a series of laboratory experiments.Oil contents(mass fraction) of 4%,8%,12%,16% and 20% were selected to represent different contamination degrees,and the soil specimens were manually prepared through mixing and static compaction method.Initial water content and dry density of the test kaolin clay were controlled at 10% and 1.58 g/cm^3,respectively.Test results indicate that since part of the diesel oil will be released from soil by evaporation,the real water content should be derived through calibration of the quasi water content obtained by traditional test method.As contamination degree of the kaolin clay increases,both liquid limit and plastic limit decrease,but there's only a slight increase for plasticity index.Swelling pressure of contaminated kaolin clay under confined condition will be lowered when oil-content gets higher.Unconfined compressive strength(UCS) of the oil-contaminated kaolin clay is influenced by not only oil content but also curing period.Increase of contamination degree will continually lower UCS of the kaolin clay specimen.In addition,electrical resistivity of the contaminated kaolin clay with given water content decreases with the increase of oil content.However,soil resistivity is in good relationship with oil content and UCS.Finally,oil content of 8% is found to be a critical value for engineering property of kaolin clay to transit from water-dominated towards oil-dominated characteristics.

Comparative Studies on Biodegradative Abilities of <i>Pleurotus ostreatus</i>and <i>P. pulmonarius</i>in Soils Contaminated with Crude and Used Engine Oils

Crude and used engine oil degrading ability of two white rot fungi Pleurotus ostreatus and P. pulmonarius were investigated for six months. One hundred grams of sterilized soil moistened with 75% distilled water (w/v) were weighed into 9 × 9 × 4 cm (350 cm3) jam bottles and mixed thoroughly with bonny light crude oil and used engine oil at different concentrations (0%, 5%, 10%, 15%, 25% and 30%), separately. Each bottle was then inoculated with two agar plugs of a vigorously grown mycelium of P. ostreatus and P. pulmonarius using a sterile cork borer. The bottles were incubated at room temperature for 6 months. The mycelia-ramified waste was separated from soils and analysed for physicochemical parameters such as organic matter, carbon, nitrogen, phosphorus, potassium, pH and total hydrocarbon content, (THC) after drying. The organic carbon, nitrogen and phosphorus contents in contaminated and inoculated soils were increased after six months. However, decrease in potassium, pH and THC occurred in these soils after the period of investigation. P. ostreatus reduced the initial THC to 8% and 9% in soils contaminated with 20% of crude and engine oils, respectively, which was lower than that of P. pulmonarius. The two white rot fungi could be exploited in bioremediation of soils contaminated with bonny light crude and used engine oils.

Formation mechanism,experimental method,and property characterization of graindisplacing methane hydrates in marine sediment:A review

Grain-displacing hydrate deposits exist at many marine sites,which constitute an important part of methane hydrate resources worldwide.Attributed to the difficulties in acquiring field data and synthesizing experimental samples,the formation and property characterization of grain-displacing hydrate remains less understood and characterized than the pore-filling hydrate in current literature.This study reviews the formation mechanisms of grain-displacing hydrate from the perspective of geological accumulation and microscale sedimentary property.The experimental methods of synthesizing grain-displacing hydrate in the laboratory and the current knowledge on the property of grain-displacing hydrate sediment are also introduced.Shortcomings in current theories and suggestions for future study are proposed.The work is hoped to provide valuable insights for the research into the hydrate accumulation,geophysics,and hydrate exploitation targeted at the grain-displacing hydrate in the marine sediments.

Treatment of engine-oil polluted wastewater with a mixed bacterial flora and kinetics of biodegradation

A mixed bacterial flora was isolated from the soil of two petroleum-contaminated sites, then cultivated and domesticated in an open environment. The bacteria were used to degrade engine oil in wastewater. The optimum biodegradation conditions for all engine oil concentrations of respectively 489 mg L^-1, 1. 075 mg L^-1 and 2 088 mg L^-1 are bacterial inoculum concentration of 0.1%, temperature at 30 ℃ to 35 ℃, pH 7.0 to 7.5, and rotation at 190 r mia^-1 to 240 r rain^-1. The second-order kinetic model proposed by Quiroga and Sales describes the characteristics of the biodegradation of the engine oil very well. Engine oil concentration barely changes the growth rate of the bacterial consortium. The mixed bacterial flora has a high biodegrading capability for engine oil.

Morphological Evaluation of PLA/Soybean Oil Epoxidized Acrylate Three-Dimensional Scaffold in Bone Tissue Engineering

Tissue engineering’s main goal is to regenerate or replace tissues or organs that have been destroyed by disease,injury,or congenital disabilities.Tissue engineering now uses artificial supporting structures called scaffolds to restore damaged tissues and organs.These are utilized to attach the right cells and then grow them.Rapid prototyping appears to be the most promising technology due to its high level of precision and control.Bone tissue replacement“scaffolding”is a common theme discussed in this article.The fused deposition technique was used to construct our scaffold,and a polymer called polylactic acids and soybean oil resin were used to construct our samples.The samples were then divided into two groups;the first group was left without immersion in the simulated body fluid and served as a control for comparison.The second group was immersed in the simulated body fluid.The results of the Field Emission Scanning Electron Microscope(FESEM),Energy Dispersive X-ray Spectroscopy(EDX)and X-ray diffraction(XRD)were utilized to interpret the surface attachment to ions,elements,and compounds,giving us a new perspective on scaffold architecture.In this study,an innovative method has been used to print therapeutic scaffold that combines fused deposition three-dimensional printing with ultraviolet curing to create a high-quality biodegradable polymeric scaffold.Finally,the results demonstrate that adding soybean oil resin to the PLA increased ion attachment to the surface while also attracting tricalcium phosphate formation on the surface of the scaffold,which is highly promising in bone tissue replacement.In conclusion,the soybean oil resin,which is new in the field of bone tissue engineering,shows magnificent characteristics and is a good replacement biopolymer that replaces many ceramic and polymeric materials used in this field that have poor morphological characteristics.

Temperature Dependence of Density,Viscosity,Thermal Conductivity and Heat Capacity of Vegetable Oils for Their Use as Biofuel in Internal Combustion Engines

This work gives tools to overcome the difficulty to determine experimentally physical properties for vegetable oils within the range of temperature typically observed during the injection phase in a diesel engine. Knowing vegetable oils’ physical properties to these ranges of temperature is of fundamental importance when modeling their combustion in diesel engine. However, vegetable oils’ experimental physical properties data are rare in the literature for temperature above 523 K. This paper describes experimental measurements and estimation methods for density, dynamic viscosity, thermal conductivity and heat capacity of vegetable oils for this particular range of temperature. The methodology uses several correlative methods using group contribution approach for each property and compares experimental data with predicted one to select the more accurate model. This work has shown the rapeseed and jatropha oils’ physical properties can be satisfactorily predicted as a function of temperature using group contribution approach.

甲醇及其燃烧副产物对发动机油性能的影响研究

文章选取了一款市售普通发动机油作为研究对象,研究了甲醇及其燃烧副产物对该润滑油主要性能的影响。微动摩擦磨损试验机(SRV)摩擦磨损试验(往复模式)结果显示:甲醇及其燃烧副产物对该发动机油的减摩抗磨性能具有较大的负面影响,使摩擦副的平均摩擦系数增大19%、磨损率增大54%。这是由于甲醇及其燃烧副产物与润滑油中的减摩抗磨剂二烷基二硫代磷酸锌(ZDDP)和二烷基二硫代氨基甲酸钼(MoDTC)发生反应,导致其析出所致。抗氧化试验结果显示:加入甲醇、甲醛、甲酸三者的混合物,使得该发动机油的起始氧化温度降低7℃,在210℃下的氧化诱导期缩短7 min。曲轴箱模拟试验表明:甲醇对结焦行为影响最大,而三者混合物的引入使得该发动机油的结焦评级达10级,结焦量增加400%。此外,甲醇及其燃烧副产物的加入会使润滑油碱值下降幅度增大,并导致黏度指数改进剂析出,从而使其运动黏度下降。

玉米秸秆油对老化沥青流变性能的影响及其再生效果研究

玉米秸秆油作为生物油的一种,具有低碳可再生的优势,同时还有能恢复老化沥青性能潜力。为进一步促进玉米秸秆油在道路工程中的应用,该文通过室内试验探究玉米秸秆油作为一种再生剂对老化沥青流变性能的影响,并对其再生效果进行分析。在此基础上,利用红外光谱试验与凝胶渗透色谱试验,揭示玉米秸秆油再生剂的再生机理。结果表明:玉米秸秆油的加入,改变了老化沥青的组分比例,并在一定程度上恢复了沥青胶体结构的稳定性,对老化沥青起到稀释及调和作用,从而恢复老化沥青的物理及流变性能,但恢复效果受玉米秸秆油掺量的影响;当玉米秸秆油掺量为20%时,其对老化沥青性能的再生效果最为显著。

Wear and performance analysis of a 4-stroke diesel engine employing nanolubricants

In the present study, the performance of a 4-stroke diesel engine was experimentally evaluated upon adding Al2O3 or SiO2 nanoparticles to the engine oil （SAEISW40）. The viscosity and density of the resulting nanolubricants were determined while varying both the nanoparticle volume fraction and the temperature. Field emission scanning electron microscopy （FE-SEM） showed that the nanoparticles had a spherical morphology and dynamic light scattering analysis determined some aggregation of the nanoparticles in the engine oil. A pin-on-disc test apparatus was used for friction and wear analysis in the presence of the nanolubricants. Examination of wear scars by FE-SEM and energy dispersive spectroscopy found evidence of ball bearing and surface polishing effects, which were responsible for improvements in the tribological properties of the oil. The performance of these nanolubricants in a 4- stroke diesel engine test rig was assessed, and the greatest improvements in the tribological behavior and engine performance were observed when employing 0.3 vol% Al2O3.

ILSAC GF-7发动机油规格分析

目前汽车工业高度重视节能与环保,因此发动机油也必须适应相关要求。全球各个组织提出了不同的发动机油规格,并根据发动机技术的发展不断修订。国际润滑剂标准化和批准委员会(ILSAC)提出的GF-7规格将于2025年1季度正式实施,针对其主要修订内容进行讨论分析。与GF-6规格相比,GF-7规格对发动机油的部分理化性能指标进行加严,同时对橡胶相容性,燃油经济性,高温氧化性,正时链条防护等性能提出了更高的要求,还增加了老化油的低速早燃(LSPI)评估项目。本次ILSACGF-7规格的更新将为发动机油的开发带来全新的机遇与挑战。

加氢光亮基础油在CF-4 20W-50柴油机油中的应用研究

通过加氢工艺可使光亮基础油提质改性,进而改善以其为原料的发动机油综合性能。对不同种类150BS基础油在CF-420W-50柴油机油中的应用进行考察,对比了黏温特性、低温性能与清净性能等指标,验证了加氢150BS基础油更加优秀的实际使用性能。同时还可进一步增大加氢150BS基础油使用量,调整黏度指数改进剂的加剂量,与6号或10号等不同牌号基础油搭配调合CF-420W-50柴油机油。调合得到的成品油可有效兼顾100℃运动黏度与-15℃低温动力黏度,表明加氢150BS基础油在CF-420W-50柴油机油中具备良好的应用可行性。

内燃机油中基础油和黏度指数改进剂的选用探究

内燃机油通常由基础油、功能复合剂、黏度指数改进剂以及降凝剂等调合组成。黏度指数改进剂是常用的改善润滑油黏温特性的功能添加剂。主要探讨了乙烯丙烯共聚物(OCP)、氢化苯乙烯-双烯共聚物(HSD)以及聚甲基丙烯酸酯型(PMA)这3种黏度指数改进剂在4种基础油中的功能特性差异,以及考察这3种黏度指数改进剂调合同一黏度级别的内燃机油,产品的黏温性能、低温性能及抗剪切能力之间的差异。充分了解了不同黏度指数改进剂在不同基础油中的性能表现,并选择合适的基础油、黏度指数改进剂进行配伍生产,对控制配方成本和指导实际生产具有重要意义。

基于分子动力学的废植物油再生沥青扩散行为研究

为研究不同废植物油掺配量、扩散温度及时间对废植物油与老化沥青相互扩散行为的影响,提出了考虑沥青老化程度随沥青膜深度变化的三层分子扩散模型,并结合傅里叶红外光谱(FTIR)测试及宏观尺度的软化点试验,分析废植物油再生剂与老化沥青之间的相互扩散行为。结果表明:废植物油再生剂通过补充老化沥青中的轻质组分、减少沥青质的团聚从而实现老化沥青的再生。温度的升高、废植物油掺量及扩散时间的增加均会增强废植物油与老化沥青的相互扩散效率,其中温度的影响最为显著;但随着温度增高,其对于扩散效率的增幅程度降低。皮尔逊相关性分析结果显示,模拟与宏观之间扩散系数相关性显著,三层分子扩散模型能够有效表征再生剂与老化沥青的相互扩散行为。

高氟含量氟橡胶在航空润滑油中的老化行为

以高氟含量氟橡胶(FKM)为研究对象,考察了其在多种航空发动机润滑油中的高温耐介质性能,研究了润滑油种类差异导致高氟含量FKM硫化胶在物理机械性能方面的变化。结果表明,在温度200℃、时间72 h的润滑油中老化后,高氟含量FKM硫化胶仍可保持良好的压缩回弹性能,体积变化率均低于12%,力学性能轻微衰减,邵尔A硬度下降明显;对于不同种类的油品,高氟含量FKM硫化胶的力学性能衰减和体积变化率均表现出差异;润滑油在高温下对高氟含量FKM硫化胶的侵蚀作用包括物理溶渗和化学腐蚀。

生物油/胶粉改性沥青性能研究

为解决高掺量胶粉改性沥青的存储稳定性问题,采用生物油与胶粉复合改性方法制备胶粉改性沥青和生物油/胶粉改性沥青。通过常规物理性能试验及流变试验,研究了复合改性沥青的存储稳定性及高低温性能。试验结果表明:生物油有效提升了胶粉改性沥青的存储稳定性;生物油/胶粉改性沥青的高温性能略低于胶粉改性沥青;生物油能够提升胶粉改性沥青的低温性能。

废植物油再生沥青流变性能研究

为有效提升废植物油的再生利用效率,研发出基于废植物油生产的再生剂,以便实现对沥青的再生利用。针对老化沥青在不同废植物油再生剂作用下的特性,包括闪点、质量损失、针入度、软化点、延度、黏度,高低温稳定性、频率特性等流变性能指标,构建植物油基础油(代号YJ)掺量与其再生沥青物理指标、流变性能指标之间的对应函数。研究发现,老化沥青的针入度受生催化剂影响,后者的加入提高了针入度,再生沥青针入度与YJ掺量之间有着较好的线性关系。加入再生剂后,软化点降低,二者呈线性关系,且掺量越高,改善越明显。随着YJ掺量的增加,再生沥青的初始模量不断降低。当YJ掺量为10%时,老化沥青含再生剂时,可显著改善老化沥青在低温条件下的抗塑性变形能力,使再生沥青逐渐达到与原样沥青同等的初始模量水平。在YJ掺量5%时,可恢复老化沥青疲劳性能至原样沥青水平。老化沥青的低温抗裂能力随着植物油再生剂的加入而有所提高,抗裂效果与YJ掺量是正相关的。研究进一步表明,植物油再生剂不利于老化沥青的抗变形能力。

废旧塑料/植物油复合再生沥青流变性能研究

为研究废旧塑料(PE)与植物油(Plant oil,PO)复合再生沥青流变性能,选用70#A级沥青作为基质沥青,采取室内老化的方式制备老化沥青,并通过正交试验获取废塑料、植物油最佳的掺量水平以及最佳制备温度,开展复合再生沥青流变性能研究。试验结果表明:植物油掺量6%、PE掺量6%、制备温度160℃时,复合再生沥青的三大指标较优;植物油掺入老化沥青后显著改善老化沥青的低温性能,降低老化沥青的黏度,但相比基质沥青高温性能有明显降低;而经过废塑料复合改性再生后,提高了植物油再生沥青的高温性能,增加了植物油再生沥青的黏性,同时对再生沥青的低温性能也有增益作用。复合再生沥青的高温性能、疲劳性能、低温性能明显优于植物油再生沥青。

二冲程汽油机润滑油生物降解性及其评定方法的研究

参照欧洲CEC标准创新性地建立了二冲程汽油机油生物降解性能评定方法,该方法所得实验结果与国外已公布的类似方法评定结果相比,具有良好相关性,且方便、可靠、重复性好、更符合我国的实际。考察了二冲程油基础油和商品二冲程油的生物降解性能,为评估二冲程油对环境的影响和开发国产生物降解二冲程油打下了良好的基础。

生物重油再生沥青物理性能试验研究

为研究生物重油对老化沥青再生的可行性,选取3种生物重油进行试验。对3种生物重油进行比重、黏度、水分含量、元素分析、红外光谱等理化性能测试;将3种生物重油按照2%、4%、6%、8%的比例掺配至经室内模拟老化后的70#沥青中,通过针入度、延度、软化点、黏度试验,对比分析3种生物重油对70#老化沥青再生效果的差异性;参照沥青混合料最佳沥青用量的方法确定生物重油的最佳掺量。结果表明:随生物重油掺量的增加,老化沥青软化点和黏度呈下降趋势,针入度和延度呈上升趋势;生物重油再生性能存在一定的差异性,生物重油A和B再生性能较好,生物重油C再生性能稍差;生物重油A、B、C最佳掺量分别为3.9%、4.6%、6.4%。

R410A制冷剂和POE VG68润滑油混合物热物性模型

含油制冷剂的热物理性质是准确计算制冷系统热力性能及评价润滑油对换热和压降影响的基础。给出了基于实验的适用于R410A制冷剂/POE VG68润滑油新型工质对的热物性计算方法。这些物性计算模型简结、可靠,模型对物性参数的预测值与实验值的偏差均在5%以内,所有计算模型可用来计算R410A/POE VG68新型工质对在常见工况范围内的物性数据,为R410A制冷空调系统性能设计及分析提供了准确、可靠的热力学参数,同时可用于分析评价R410A制冷系统中润滑油不同循环量对系统及其主要部件性能的影响。