Production Of Lubricants Research Articles

Molecular Dynamics Simulation on the Aggregation of Lubricant Oxidation Products

The aggregation phenomenon of lubricant oxidation products, fatty acids, fatty alcohols, aliphatic aldehydes and aliphatic ketones in base oil, was probed by molecular dynamics (MD) simulation. The results show that there are aggregates formed in fatty acids or fatty alcohols, and that the aggregation does not occur in aliphatic aldehydes and aliphatic ketones in single component models. Fatty acids or fatty alcohols are connected by hydrogen bonds in the form of dimers or multimers. The hydrogen bond can be formed at a higher temperature in fatty acids, but not in fatty alcohols. In the mixture models, there are dimers and/or multimers constructed by different molecules of lubricant oxidation products, and the multimers have a chain or a ring structure. The number of molecules involved in the formation of aggregates decreases with the increase of temperature. The opportunity to construct hydrogen bonds rises with the increasing concentration of oxidation products. Obvious aggregation occurs at 25 and 100 °C in conditions of high concentration, while it happens only at 25 °C with lower concentration. It is easier for fatty acids and fatty alcohols to form hydrogen bonds and the formed hydrogen bonds are more stable, which result in a higher concentration of fatty acids and fatty alcohols in the aggregates. Fatty acids and fatty alcohols are possibly more significant in the formation of aggregates and it may be beneficial to prevent the aggregation by controlling the concentration of them in lubricating oil.

Passive water collection with the integument: mechanisms and their biomimetic potential.

Several mechanisms of water acquisition have evolved in animals living in arid habitats to cope with limited water supply. They enable access to water sources such as rain, dew, thermally facilitated condensation on the skin, fog, or moisture from a damp substrate. This Review describes how a significant number of animals - in excess of 39 species from 24 genera - have acquired the ability to passively collect water with their integument. This ability results from chemical and structural properties of the integument, which, in each species, facilitate one or more of six basic mechanisms: increased surface wettability, increased spreading area, transport of water over relatively large distances, accumulation and storage of collected water, condensation, and utilization of gravity. Details are described for each basic mechanism. The potential for bio-inspired improvement of technical applications has been demonstrated in many cases, in particular for several wetting phenomena, fog collection and passive, directional transport of liquids. Also considered here are potential applications in the fields of water supply, lubrication, heat exchangers, microfluidics and hygiene products. These present opportunities for innovations, not only in product functionality, but also for fabrication processes, where resources and environmental impact can be reduced.

A cleaner approach for biodegradable lubricants production by enzymatic glycerolysis of castor oil and kinetic analysis

Abstract Monoricinolein (MRO) and diricinolein (DRO) were renewable and biodegradable lubricants. In this paper, MRO and DRO were prepared by the novel cleaner enzymatic glycerolysis of castor oil (CO) in solvent-free system. Three commercial immobilized lipases (Novozym 435, Lipozyme RM IM and Lipozyme TL IM) were screened and compared, and Novozym 435 showed the best catalysis performance among the tested lipases. Effects of reaction variables (reaction pressure, reaction time, temperature, enzyme load, substrate ratio and water content) on the enzymatic glycerolysis of CO were investigated. High conversion of CO (92.48 ± 1.02%) and the maximum bio lubricants yields (54.47 ± 0.58% MRO and 38.01 ± 0.50% DRO) were achieved under the following conditions: enzyme load 5% (w/w, based on the total mass), CO/glycerol ratio at 1:6, 90 °C, and 3 h. The activation energies (Ea) for CO conversion and the formation of MRO and DRO were calculated as 33.75 kJ/mol, 22.26 kJ/mol and 24.37 kJ/mol, respectively, and the process showed high selectivity toward the formation of MRO. Reaction kinetic agreed with the ping-pong Bi-Bi mechanism with the inhibition of CO, and the kinetic values ( V max , K m ′ and K IA ) were 0.0946 mol/(L·min), 1.6704 mol/L, and 0.89 mol/L, respectively.

Biotechnological production of bio-based long-chain dicarboxylic acids with oleogenious yeasts.

Long-chain α,ω-dicarboxylic acids (DCAs) are versatile chemical intermediates of industrial importance used as building blocks for the production of polymers, lubricants, or adhesives. The majority of industrial long-chain DCAs is produced from petro-chemical resources. An alternative is their biotechnological production from renewable materials like plant oil fatty acids by microbial fermentation using oleogenious yeasts. Oleogenious yeasts are natural long-chain DCA producers, which have to be genetically engineered for high-yield DCA production. Although, some commercialized fermentation processes using engineered yeasts are reported, bio-based long-chain DCAs are still far from being a mass product. Further progress in bioprocess engineering and rational strain design is necessary to advance their further commercialization. The present article reviews the basic strategies, as well as novel approaches in the strain design of oleogenious yeasts, such as the combination of traditional metabolic engineering with system biology strategies for high-yield long-chain DCA production. Therefore a detailed overview of the involved metabolic processes for the biochemical long-chain DCA synthesis is given.

Development and efficiency assessment of process lubrication for hot forging

The article considers innovative technologies in testing and production of process lubricants for hot bulk forging. There were developed new compositions of eco-friendly water-graphite process lubricants for hot extrusion and forging. New approaches to efficiency assessment of process lubricants are developed and described in the following article. Laboratory and field results are presented.

Novel Strategies for the Production of Fuels, Lubricants, and Chemicals from Biomass.

Growing concern with the environmental impact of CO2 emissions produced by combustion of fuels derived from fossil-based carbon resources has stimulated the search for renewable sources of carbon. Much of this focus has been on the development of methods for producing transportation fuels, the major source of CO2 emissions today, and to a lesser extent on the production of lubricants and chemicals. First-generation biofuels such as bioethanol, produced by the fermentation of sugar cane- or corn-based sugars, and biodiesel, produced by the transesterification reaction of triglycerides with alcohols to form a mixture of long-chain fatty esters, can be blended with traditional fuels in limited amounts and also arise in food versus fuel debates. Producing molecules that can be drop-in solutions for fossil-derived products used in the transportation sector allows for efficient use of the existing infrastructure and is therefore particularly interesting. In this context, the most viable source of renewable carbon is abundantly available lignocellulosic biomass, a complex mixture of lignin, hemicellulose, and cellulose. Conversion of the carbohydrate portion of biomass (hemicellulose and cellulose) to fuels requires considerable chemical restructuring of the component sugars in order to achieve the energy density and combustion properties required for transportation fuels-gasoline, diesel, and jet. A different set of constraints must be met for the conversion of biomass-sourced sugars to lubricants and chemicals. This Account describes strategies developed by us to utilize aldehydes, ketones, alcohols, furfurals, and carboxylic acids derived from C5 and C6 sugars, acetone-butanol-ethanol (ABE) fermentation mixtures, and various biomass-derived carboxylic acids and fatty acids to produce fuels, lubricants, and chemicals. Oxygen removal from these synthons is achieved by dehydration, decarboxylation, hydrogenolysis, and hydrodeoxygenation, whereas reactions such as aldol condensation, etherification, alkylation, and ketonization are used to build up the number of carbon atoms in the final product. We show that our strategies lead to high-octane components that can be blended into gasoline, C9-C22 compounds that possess energy densities and properties required for diesel and jet fuels, and lubricants that are equivalent or superior to current synthetic lubricants. Replacing a fraction of the crude-oil-derived products with such renewable sources can mitigate the negative impact of the transportation sector on overall anthropogenic greenhouse gas (GHG) emissions and climate change potential. While ethanol is a well-known fuel additive, there is significant interest in using ethanol as a platform molecule to manufacture a variety of valuable chemicals. We show that bioethanol can be converted with high selectivity to butanol or 1,3-butadiene, providing interesting alternatives to the current production from petroleum. Finally, we report that several of the strategies developed have the potential to reduce GHG emissions by 55-80% relative to those for petroleum-based processes.

High-Performance Lubricant Base Stocks from Biorenewable Gallic Acid: Systematic Study on Their Physicochemical and Tribological Properties

Synthesis, characterization, and evaluation of a series of gallate derivatives as lubricant base stocks are described. The gallate derivatives were synthesized via sequential esterification and alkylation reactions from biorenewable raw material gallic acid. All the synthesized gallate derivatives were structurally characterized by using NMR, IR, and HRMS spectral data. Their physicochemical and lubricating properties including density, viscosity, viscosity index, pour point, flash point, volatility, corrosion level, thermal and oxidation stability, and friction-reducing and antiwear properties were systematically investigated. On the basis of the physicochemical and lubricating data, it can be concluded that gallate derivatives have good properties in terms of viscosity–temperature characteristics, corrosion ability, volatility, and low-temperature flow ability. More important, they have predominant thermal and oxidation stability, as well as high-temperature friction-reducing and antiwear performances compared with the existing synthetic ester oils. These favorable technical performances together with their biological available resources recommend gallate derivatives as excellent base stocks for the development of high-performance green lubricant products.

Study of thermal dehydration of sodium orthophosphate monosubstituted

Depending on the conditions of conducting the synthesis, it is possible to obtain polymeric phosphates of different composition and structure. The mixtures of polyphosphates, employed in the production of technological lubricants, are expedient to synthesize by the high-temperature dehydration of sodium orthophosphate monosubstituted. The temperature ranges, over which the thermochemical transformations of sodium orthophosphate monosubstituted with the formation of polyphosphates proceed, are established by the thermogravimetric method. The composition of polyphosphates is determined using the X-ray phase analysis. Quantitative composition of the mixtures of polyphosphates is determined by applying the original method of eluent ion-exchange chromatography. It is established that the basic products of thermal dehydration of sodium orthophosphate monosubstituted in the range of temperatures 200–650 °C are Na 3 Р 3 О 9 , Na 2 H 2 P 2 O 7 and Na 6 P 6 O 18 . Thermochemical transformations of NaH 2 PO 4 into Na 6 P 6 O 18 at temperature 650 °C are accompanied by the side reactions of formation of Na 3 H 2 P 3 O 10 . We proposed the chemical scheme of the high-temperature dehydration of sodium orthophosphate monosubstituted. Kinetics of the isothermal process of obtaining the polymeric phosphates from sodium orthophosphate monosubstituted at different temperatures is examined. We established quantitative composition of the mixtures of inorganic polymeric phosphates depending on the duration of isothermal process of dehydration. The possibility of obtaining a salt mixture of polymeric phosphates of the assigned qualitative and quantitative composition is demonstrated. We proposed to use the mixture: 76 % Na 6 P 6 O 18 , 8 % Na 2 H 2 P 2 O 7 , 8 % Na 3 H 2 P 3 O 10, 8 % NaH 2 PO 4 , obtained at 650 °C, as the basic phosphate component of technological lubricants for the hot rolling of pipes.

Production of Biomass-Based Automotive Lubricants by Reductive Etherification.

Growing concern with the effects of CO2 emissions due to the combustion of petroleum-based transportation fuels has motivated the search for means to increase engine efficiency. The discovery of ethers with low viscosity presents an important opportunity to improve engine efficiency and fuel economy. We show here a strategy for the catalytic synthesis of such ethers by reductive etherification/O-alkylation of alcohols using building blocks that can be sourced from biomass. We find that long-chain branched ethers have several properties that make them superior lubricants to the mineral oil and synthetic base oils used today. These ethers provide a class of potentially renewable alternatives to conventional lubricants produced from petroleum and may contribute to the reduction of greenhouse gases associated with vehicle emissions.

Determination of the Composition and Properties of Plastic Lubricants Derived from Used Oils

A method is examined for cleaning oils using monoethanolamine and isopropyl alcohol, which permits the purification of synthetic oils for their subsequent use as dispersion media in the production of plastic lubricants. The compositions of plastic lubricants derived from Solidol J and Lithol-24 analogs produced from used oils were determined. The basic physicochemical and performance properties of experimental lubricant compositions were evaluated. The properties of plastic lubricants derived from used oils were found to be comparable or even superior to the properties of commercial analogs produced from expensive base oils.

One-pot chemo-enzymatic synthesis of furfuralcohol from xylose

Furfuralcohol (FOL) is an important intermediate for the production of lysine, ascorbic acid, and lubricants. It can be used as a hypergolic fuel in rocketry. In this study, it was attempted to synthesize FOL from xylose by tandem catalysis with solid acid SO42−/SnO2-Montmorillonite and recombination Escherichia coli CCZU-K14 whole cells. Using SO42−/SnO2-Montmorillonite (3.0wt% dosage) as catalyst, a highest furfural yield of 41.9% was achieved from xylose at 170°C for 20min. Furthermore, Escherichia coli CCZU-K14 whole cells were used for bioconverting furfural to FOL. The optimum biocatalytic reaction temperature, reaction pH, cosubstrate concentration, and substrate concentration were 30°C, 6.5, 1.5mol glucose/mol furfural, and 200mM, respectively. Finally, the yield of FOL from 200mM furfural was achieved to 100% by Escherichia coli CCZU-K14 whole cells after 24h. In conclusion, this strategy show high potential application for the effective synthesis of FOL.

Influences of chemical characteristics and nanoadditive participation on raw vegetable oils’ tribological properties

Lubricant formulations play a key role in the friction process of mechanical systems and components. Today, besides good lubricant tribological properties, there are demands concerning the impact of lubricants on environmental pollution. Numerous studies have shown that the use of additives containing microparticles and nanoparticles and/or nanopowder solid materials improve performance of mineral and synthetic lubricating oils, and offer the possibilities of using them as base for developing new lubricant products. The present paper presents the results of experimental investigations regarding MoS2 (molybdenum disulfide) nanoparticles tribological effects as additive in four raw vegetable oils. Based on obtained results it can be said that the tribological properties of different lubricant mixtures are improved, in direct link with the physicochemical properties of lubricant base (polyunsaturated vs. saturated fatty acid ratio of vegetable oils).

Oligomerization of 1-decene over sulfated alumina catalysts for the production of synthetic fuels and lubricants: modelling and verification

The three-factor Box-Behnken design and the response surface methodology (RSM) were used to optimize the production of C20 (transportation fuel) and C30 + (lubricant oil) hydrocarbons obtained from 15 different oligomerization reactions of 1-decene over sulfated alumina catalysts in batch operation mode. The physiochemical properties of the sulfated alumina catalysts were characterized by N2 sorption, XRD and NH3-TPD. The formulated quadratic models as a function of three independent variables of reaction temperature (448–473 K), sulfuric acid concentration (2.5–4.5 M) and catalyst amount (5–15 wt%) were verified by the experimental results (1-decene conversion and product composition) with a coefficient of determination higher than 0.97 for all dependent variables (conversion, amount of C20 and C30 +). The optimal amount of C20 (65.4 wt%) was achieved at 473 K, using 3.5 M sulfated alumina and 8.8 wt% of catalyst. Similarly, the optimization of C30 + (47.7 wt%) was revealed at 473 K, using 3.5 M sulfated alumina and 15 wt% of catalyst. It was concluded that oligomerization over sulfated alumina was successfully optimized using Box-Behnken design.

Gamete, Fertilization and Embryo Compatible Lubricants: The New FDA Product Code ‘PEB’ Updates the Standard of Care for Trying-to-Conceive Couples

Recently, the U.S. Food and Drug Administration created a unique Product Code (“PEB”) for personal lubricants that are “gamete, fertilization and embryo compatible” for use by couples who are trying to conceive and by health care providers during fertility interventions. This designation falls under the Obstetrical and Gynecological Therapeutic Devices portion of the Code of Federal Regulations Title 21. These Class 2 lubricant devices differ from other patient and personal lubricants (e.g. not specifically gamete, fertilization and embryo compatible) with regards to the required biocompatibility and toxicology testing; lot release specifications; quality monitoring; and premarket FDA review process for device clearance. The PEB lubricants undergo premarket testing and ongoing monitoring more similar to Reproductive Media and Supplements, than to traditional lubricants. Inspite of the testing and regulatory requirements for this Product Code, many consumers, physicians, and medical-specialty societies remain unaware of this specific labeling, which can simplify optimal product selection for a unique patient group. This review briefly discusses: how PEB lubricants (e.g. “Fertility Lubricants”) differ from other types of lubricants; why product choice in lubricants matters for couples who are trying to conceive; and general formula differences between current PEB Lubricants. The awareness of a new regulatory code, which identifies lubricants that are gamete, fertilization and embryo compatible, remains lacking amongst healthcare providers and consumers. Public and reproductive health is better served if intended uses of lubricant products are read, understood and explained to patients.

Effect of reaction parameters on the decarboxylation of oleic acid over Pt/ZIF‐67membrane/zeolite 5A bead catalysts

AbstractBACKGROUNDCarboxylic acids obtained from biomass raw materials are attractive starting chemicals in the conversion to linear, paraffinic hydrocarbons. The resultant hydrocarbon products can be used as platform chemicals for the production of fuels, lubricants and other valuable chemicals.RESULTSThe effects of reaction parameters on the decarboxylation of oleic acid to paraffins, and hydrocarbons over Pt supported on zeolite 5A beads coated with ZIF‐67 membrane (Pt/ZIF‐67 membrane/zeolite 5A) were investigated. Almost complete conversion of oleic acid was observed for all reaction conditions studied here. The catalysts displayed high selectivity to heptadecane even with as low as 0.5 wt% Pt loading. Moderate reaction temperature and pressure were favorable to obtain high yield of heptadecane. The catalysts displayed a slight decrease in catalytic activity after recycling. Interestingly, of all explored reaction conditions, the catalysts exhibited the highest selectivity to heptadecane (∼91%) in the presence of CO2.CONCLUSIONThe results from this work demonstrate that the studied reaction parameters greatly affected the overall catalytic performance (mainly product distribution) for the decarboxylation of oleic acid into heptadecane over Pt/ZIF‐67 membrane/zeolite 5A catalysts. © 2016 Society of Chemical Industry

Kinetics of hydrogenation and hydrogenolysis of 2,5-dimethylfuran over noble metals catalysts under mild conditions

Ketones, derived via the selective ring-opening hydrogenation of biomass-derived furanic compounds, are useful synthons for the production of fuels and lubricant. In this study, 2,5-dimethylfuran (DMF) was used as a model to investigate the liquid-phase hydrogenation of substituted furans over noble metals. The activity and selectivity of carbon-supported Pt, Pd, Rh, and Ru were compared under identical conditions. Pt/C exhibited the highest activity and selectivity for CO bond hydrogenolysis, whereas all other catalysts exhibited a high selectivity for ring hydrogenation to form 2,5-dimethyltetrahydrofuran. The reaction kinetics were measured in detail for liquid-phase hydrogenation of DMF over Pt/C, under conditions that excluded the effects of internal or external mass transfer (333K–363K, pH2=0.41–0.69MPa). A reaction mechanism is proposed to explain the parallel formation of 2,5-dimethyltetrahydrofuran, 2-hexanone, and 2-hexanol. This mechanism is consistent with what is known about the adsorption of DMF on Pt, and explains why ring opening occurs directly from adsorbed DMF and not via secondary reaction of 2,5-dimethyltetrahydrofuran. The kinetics of DMF hydrogenation are well represented by the mechanism and the assumption of non-competitive adsorption of organic species and hydrogen atoms. The step involving CO bond cleavage of the aromatic ring had the highest activation energy, 45.4kJ/mol, and is favored over the steps involving CC bond hydrogenation of the furan ring at elevated temperatures and low pH2. The reaction kinetics reveal that DMF hydrogenation can be tuned to produce 2-hexanone with 92% selectivity at 100% conversion under relatively mild liquid phase conditions (0.41MPa, 393K).

특허 지표 분석을 통한 국내 윤활유 제조 기술 평가

본 연구에서는 윤활유 제조기술에 관한 국내외 특허 활동 분석을 통하여 윤활유 제조산업에서의 한국의 기술 경쟁력 분석 및 향후 대응 전략을 제시한다. 이를 위하여 본 연구에서는 한국을 비롯하여 미국, 일본 및 유럽연합 등 윤활유 제조산업에서의 주요 선진국들의 9가지 주요 윤활유 제조기술에 관한 최근 특허 동향을 통계적으로 분석한다. 또한 특허 수, 특허 인용수, 시장확보지수, 특허영향지수, 기술력지수 등 주요 특허 활동 평가 지표 분석을 통하여 한국의 윤활유 제조산업에서의 기술력, 경쟁력 등을 정량적으로 평가한다. 주요 결과로 한국은 뒤늦은 기술개발 등으로 윤활유 제조산업 진입은 상대적으로 늦으나 빠른 국내기술 확보를 통하여 높은 수준의 국내 기술을 보유하고 있다. 반면 상대적으로 낮은 국외 특허 활동으로 인하여 국내 기술의 국외 시장 진출이 용이치 않음을 분석하였다. 이 결과를 바탕으로 친환경 윤활유 시장 및 선진 기술 등 미래 유망 기술 전망 및 한국의 특허 전략을 제시한다. We evaluate the technical competitiveness of Korea in lubricating oil industries by comparatively analyzing the patent activities. In achieving the goal, we collect and statistically analyze the historical patent data of lubricants production technologies. We here consider nine technology groups classified by their raw material types and process features of four countries such as USA, Japan, EU and Korea. We then evaluate Korea's competitiveness in lubricating oil industries using different patent index including patent family size, cites per patent, patent impact index and technology strength. Based on the evaluation results, we finally propose the practical strategies to improve Korea's competitiveness in lubricants industries.

Statistical evaluation and modeling of cheap substrate-based cultivation medium of Chlorella vulgaris to enhance microalgae lipid as new potential feedstock for biolubricant

ABSTRACTChlorella vulgaris (C. vulgaris) microalga was investigated as a new potential feedstock for the production of biodegradable lubricant. In order to enhance microalgae lipid for biolubricant production, mixotrophic growth of C. vulgaris was optimized using statistical analysis of Plackett–Burman (P-B) and response surface methodology (RSM). A cheap substrate-based medium of molasses and corn steep liquor (CSL) was used instead of expensive mineral salts to reduce the total cost of microalgae production. The effects of molasses and CSL concentration (cheap substrates) and light intensity on the growth of microalgae and their lipid content were analyzed and modeled. Designed models by RSM showed good compatibility with a 95% confidence level when compared to the cultivation system. According to the models, optimal cultivation conditions were obtained with biomass productivity of 0.123 g L−1 day−1 and lipid dry weight of 0.64 g L−1 as 35% of dry weight of C. vulgaris. The extracted microalgae lipid presented useful fatty acid for biolubricant production with viscosities of 42.00 cSt at 40°C and 8.500 cSt at 100°C, viscosity index of 185, flash point of 185°C, and pour point of −6°C. These properties showed that microalgae lipid could be used as potential feedstock for biolubricant production.

Biochemical characterization and substrate specificity of jojoba fatty acyl-CoA reductase and jojoba wax synthase

Wax esters are used in industry for production of lubricants, pharmaceuticals and cosmetics. The only natural source of wax esters is jojoba oil. A much wider variety of industrial wax esters-containing oils can be generated through genetic engineering. Biotechnological production of tailor-made wax esters requires, however, a detailed substrate specificity of fatty acyl-CoA reductases (FAR) and wax synthases (WS), the two enzymes involved in wax esters synthesis. In this study we have successfully characterized the substrate specificity of jojoba FAR and jojoba WS. The genes encoding both enzymes were expressed heterologously in Saccharomyces cerevisiae and the activity of tested enzymes was confirmed by in vivo studies and in vitro assays using microsomal preparations from transgenic yeast. Jojoba FAR exhibited the highest in vitro activity toward 18:0-CoA followed by 20:1-CoA and 22:1-CoA. The activity toward other 11 tested acyl-CoAs was low or undetectable as with 18:2-CoA and 18:3-CoA. In assays characterizing jojoba WS combinations of 17 fatty alcohols with 14 acyl-CoAs were tested. The enzyme displayed the highest activity toward 14:0-CoA and 16:0-CoA in combination with C16-C20 alcohols as well as toward C18 acyl-CoAs in combination with C12-C16 alcohols. 20:1-CoA was efficiently utilized in combination with most of the tested alcohols.

Catalyst-Free Aldol Reaction in a Water Medium

Background: With growing interest in developing environmentally friendly reactions and atom-economic processes in recent years, the utilization of water as a solvent has attracted a great deal of attention. This is not only for its low-cost, safe and environmentally benign nature, but also the unique properties of water in promoting reactions. Moreover, it may afford new access to the compounds that required harsh reaction conditions under traditional approaches. The aldol reaction is one of the most useful and widely employed methods for carbon - carbon bond formation in organic synthesis. Aldols can be acted as the raw materials used for the production of lubricants, surface coatings, synthetic resins and the important intermediates in the synthesis of polyols. Methods: p-nitrobenzaldehyde (100 mg), acetone (1.5 ml) and water (2 ml) was added into a round bottom at N2 atmosphere. The suspension was stirred vigorously at 50°C for 48 h. Then the reaction mixture was diluted with brine (10ml) and extracted with 3 × 15 ml ethyl acetate. The organic layer was dried over anhydrous MgSO4. Then the ethyl acetate solution was filtered and evaporated in vacuum. The crude mixture was purified by flash column chromatography on silica gel using petroleum/ ethyl acetate (2/1) as the eluent to give the desired aldol product in 92.0%. All the compounds were spectroscopically characterized (IR, 1H NMR). Results: In the examination of electron-withdrawing groups, a pronounced steric effect was more evident in the ortho position than other positions of nitrobenzaldehydes. The electronic effect influenced the reactions dramatically. No reaction progress was detected when p-methyl benzaldehyde was employed in the identical reaction condition. With increase of carbon number of ketones the yields decreased noticeably, although the temperature was elevated to reflux situations. This was partially for the increase of substrate’s steric bulk. When the acetyl benzene was used as substrate, the reaction gave poor yield. Compared to acetone, cyclic ketones reacted more slowly in reactions. When cyclic ketones were used as substrate at 50°C, only trace amounts of the desired product were obtained. Luckily, when increasing the reaction temperature to reflux conditions, for cycloheptanone, cyclohexanone and cyclopentanone, the yields reached to 86.1%, 91.4% and 56.1% respectively. The decrease was possibly due to the influence of ring strain. More interestingly, an excellent yield was obtained when 4-methylcyclohexanone was used in the reaction. In addition, nicotinaldehyde was used to react with cyclohexanone and afforded the target product in a good yield. Conclusion: In summary, a new methodology has been developed using water as solvent and promoter that is associated with non-flammable, non-toxic reaction medium, mild conditions, easy operation and good yields. The attractive function of water in aldol reaction was observed compared with many organic solvents. The approach was expanded successively to a wide range of substrates, especially cyclic ketones. Keywords: Aldehydes, aldol reaction, catalyst-free, cyclic ketones, eco-friendly, water.