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Polyalkylmethacrylates (PAMAs) are well-known as viscosity index improvers and dispersant boosters. This paper shows that PAMAs are able to adsorb from oil solution on to metal surfaces, to produce thick, viscous boundary films.These films enhance lubricant film formation in slow speed and high temperature conditions and thus produce a significant reduction of friction. A systematic study of this phenomenon has made use of the highly flexible nature of PAMA chemistry. A range of dispersant and non-dispersant polymethacrylates has been synthesized. The influence of different functionalities, molecular weights and architectures on both boundary film formation and friction has been explored using optical interferometry and friction-speed charting. From the results, guidelines have been developed for designing PAMAs having optimal boundary lubricating properties.Through their ability to form boundary films PAMAs can significantly contribute to reduce wear in engine, gear and hydraulic lubrication. As a consequence of their viscometric and tribological performance PAMAs can furthermore improve fuel and energy efficiency in different, namely engine and hydraulic applications.Extensive work is currently conducted in the lubricant industry to develop engine oils with lower sulfur, phosphorus and metal content (low SAPS) and to optimize their frictional properties through the use of friction modifiers or synthetic base stocks. We have investigated the contribution of PAMA viscosity index improvers and boosters to improve fuel economy and to reduce wear levels. This paper reports our efforts to develop a new range of PAMAs that have been optimized in terms of composition, architecture, molecular weight and functionality and which can be used in low viscosity, low SAPS formulations to help meet the stringent requirements of modern engine oils.  相似文献   

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1 Influence of PAMAon Boundary Fil mFormation and Friction1.1 Experi mental methodsUltra-thin optical interferometry has been used tostudy thinlubricating fil ms for more than a decade and theexperi mental details of this technique have been reportedpreviously[1].The principle of the test setup is shown inFigure1.A polished steel ball is loaded and rolled againstthe flat surface of a glass disc that is coated with a thinsemi-reflecting chromiumlayer and a silica spacer of about500nmthickne…  相似文献   

5.
Abstract

Surface characteristics of the prepared nickel catalysts containing 7, 10, and 13 wt% Ni w/w over different supports—silica gel, γ-alumina, and aluminosilicate—were investigated. Surface areas, total pore volumes, and average pore radii were determined for all catalysts. Pore analysis was discussed based on Vl-t plots and pore size distribution. The measured surface areas and pore volumes of pure supports increased in the following order: γ-alumina < aluminosilicate < silica gel. Pore analysis showed that SiO2 and Al2O3-SiO2 and their supported Ni samples were characterized by presence of narrower mesopores of ink-bottle type. Al2O3 was distinguished by presence of two distinct pore types, both showing continual increase in fraction with a shift to larger dimensions upon loading with nickel. Penetration and/or incorporation process of Ni particles took place at the expense of their interaction with Al+3. SiO2 revealed a gradual increase in surface parameters upon loading with nickel. For Al2O3-SiO2—supported samples, the result proposed the interaction of Ni with both alumina and silica contents of the support regardless of the penetration process.  相似文献   

6.
Abstract

The demand for high quality middle distillates is increasing world wide while the demand for residue and fuel oil is decreasing. Hydrocracking is the major conversion process that meets the twin objectives of producing more middle distillates of very high quality. Since hydrocracking is a capital-intensive process, many refiners consider the option of converting their existing vacuum gas oil hydrotreating units into mild hydrocracking units. The use of mild hydrocracker bottom as FCC feedstock can improve the quality of FCC products. In view of the advantages of mild hydrocracking process, it is essential to understand the process, catalysts used, reactions, kinetics, and advantages. This article reviews recent literature on MHC process, various catalysts used, reactions involved and advantages of mild hydrocracking process in terms of improved product qualities and increased distillates. The kinetics of the mild hydrocracking process and kinetic challenges with respect to aromatic saturation have been summarized. The limitations of the process and future scope of work in this area are also discussed briefly.  相似文献   

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1. Introduction The East Fukang Slope is located in the east of the Changji Sag and on the junction of the middle-south of the Zhangbei Fault-fold Zone and the Baijiahai Salient in the northeast of the Junggar Basin, Northwest China, with an area of about 5,000 square kilometres (Fig. 1). When the Jurassic was deposited, a huge slope with a north-south dip was formed, which consisted of the Wucaiwan Sag, front of the Kelameili Mountain piedmont, the Baijiahai Salient and the East Fuka…  相似文献   

8.
Abstract

The authors give a coupled system model of differential equations concerning dryness fraction of gas, pressure, and temperature in high temperature–high pressure steam injection wells according to mass, momentum, and energy balances. They present an algorithm solution model, along with the fourth-order Runge-Kutta method. The basic data from a high temperature–high pressure gas wells (7,100 m deep) in China were used for a case history calculation and a sensitivity analysis was also carried out. The gas flow law and the characteristic of heat transfer in formation were intuitively reflected in the algorithm and simulation. The results provide some technical insight in the process of designing well testing in high temperature–high pressure gas wells and the dynamic analysis of injection.  相似文献   

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1.Introduction The Asri basin is oval in shape,covering about2500km2from north to south.The maximum thickness at the depocenter is around18,000feet(5,500m).It is adjacent to the Hera basin in the west and to the Sunda basin in the southwest(Fig.1).Now it is under the Java sea.The basement consists of granites,granodiorites,marbles,schists and quartzites(Tonkin and Himawan,1999).In the early Tertiary,the eastern side of the basin was a steep slope controlled by syn-rifting,and the western s…  相似文献   

10.

Technology

In memory of a comrade, Aleksandr Fedorovich Lunin, 1938–1993  相似文献   

11.
Potential source rocks west of the central Anatolia basin, in Beydili/Nall?han (Turkey) include Paleocene-Eocene oil shale. Organic geochemical analyses show that the organic components in oil shale are of mainly algal-amorphous organic matter, indicating that they are marine (mainly type I–II kerogen). The organic carbon content of Beydili rocks ranges from 1.35 to 11.12 wt%, Göksarl?k Tepe rocks 1.06 to 13.8 wt%, and Kepeztepe rocks 1.55 to 11.31 wt% They have source rock quality for oil generation. The Paleocene-Eocene oil shale is in the early stage of oil generation. The redox conditions of depositional environment in three different areas have a transition period from oxic to anoxic.  相似文献   

12.
Terminal fans have formed the sedimentary system of the 2+3 sands of the upper second member, Shahejie formation in the west of the Pucheng Oilfield, Bohai Bay Basin, East China. Based on well logging data and physical properties of the reservoir beds, the 2+3 sands were divided into 16 sublayers. The heterogeneity of reservoir beds and distribution of interlayers and seal layers in the 2+3 sands were investigated. The intra-layer heterogeneity and inter-layer heterogeneity primarily belong to the severely heterogeneous classification. The spatial differentiation of sedimentary microfacies resulted in a change of reservoir bed heterogeneity, strong in the middle and southern parts, weak in the northern part. Spatial distribution of interlayers and seal layers is dominated by sedimentary microfacies, and they are thick in north-eastern and middle parts, thin in the south-western part.  相似文献   

13.
Abstract

Nickel metal was loaded in different percentages (7, 10, and 13% w/w) on different supports (H-mordenite, H-ZSM-5, and γ–alumina). The prepared catalyst samples were tested in cyclohexane conversion using microreactor pulse technique. Structure was followed up by XRD analysis. Chemisorption of tert-butylamine (TBA) was adopted for estimating the number of surface acid sites. It was found that all prepared samples displayed cracking activity, being mostly related to the fraction of acid sites remaining on the surface after coverage with supported Ni atoms. H-mordenite-supported samples exhibited mainly isomerization functionality by showing a larger portion of surface acid sites. H-ZSM-5-supported samples showed higher dehydrogenation activity. Agglomeration seemed to be responsible for lower activity of the sample of higher Ni content. The formed NiOOH phase was suggested to be responsible for increased dehydrogenation activity on H-ZSM-5 samples and increased cracking activity on γ–alumina-supported samples of higher Ni content.  相似文献   

14.
Consumers around the world increased consumption of fish and fish products in recent years due to recognition of their nutritional value. Frequent occurrences of food safety scares heightened public awareness causing significant reduction in the consumption of the affected products. Many countries, including China, implemented a traceability system to increase vertical coordination and guarantee safety in fish products. This paper aims to provide information on consumers’ awareness to quality and safety of fish products, purchasing behavior, and willingness to pay (WTP) for safe fish products in Beijing, China, based on a survey of consumers. The results show a shortage of safety knowledge among customers concerning fish products, including processing, storage, and the traceability system. The age of consumers, educational level, the perception safety and the average price, are the main determinants of Beijing consumer’s WTP for the traceable products. On average, consumers are willing to pay a 6% premium for safe, traceable fish products over the price of non-traced products of uncertain safety.  相似文献   

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The diagenetic processes of the Tabei sandstones in the Tarim Basin include compaction, cementation (quartz overgrowths, calcite, clay minerals and a minor amount of pyrite), and dissolution of the feldspar and calcite cement. Porosity was reduced by compaction from an assumed original 40% to about 22.1%. Cementation reduced porosity to 26.6%. The Tabei sandstones lost a little more porosity by compaction than by cementation. Quartz cementation, especially syntaxial quartz overgrowth, is a major cause of porosity-loss in many reservoirs in moderately to deeply buried sandstone. Calcite cementation played a key role in the porosity evolution of sandstones. At the early stage of burial, the early calcite cement occupied most of the pore spaces resulting in significant porosity. On the other hand, some primary porosity has been preserved due to incomplete filling or the presence of scattered patches of calcite cement. In addition to calcite, several clay minerals, including illite and chlorite occurred as pore-filling and pore-lining cements. The pore-lining chlorite may have helped in retaining the porosity by preventing the precipitation of syntaxial quartz overgrowths. Illite, which largely occurred as hair-like rims around the grains and bridges on the pore throats, caused a substantial deterioration of penetrability of the reservoir. Calcite cement dissolution was extensive and contributed significantly to the development of secondary porosity.  相似文献   

16.
The Yong’an-Meitai area is the focus of the present exploration in the Fushan Depression, Beibuwan Basin, South China Sea. All oils from this area are geochemically characterized by higher Pr/Ph ratio, higher proportion of heavy molecular weight hydrocarbons, and higher proportion of C29 regular steranes, which indicate that the organic matter of source rocks might have been deposited in an oxidizing palaeoenvironment and be dominated by higher plant organic matter input. The oil from E3w2 (the second member of Weizhou Fm. of the Oligocene) has a much higher density, relatively higher Pr/nC17 and Ph/nC18 ratios, and a “UCM—unresolved complex mixture” on gas chromatograms, which indicate that it has been slightly biodegraded. CPI and other terpane and sterane isomer ratios suggest they are all mature oils. The timing of oil charging in E3w2 and E2l1 (the first member of the Liushagang Fm. of the Eocene) determined by the homogenization temperatures of fluid inclusions and thermal evolution history are from 9-3 Ma and 8-3 Ma, respectively. Thus, the interpretation of E3w2 as a secondary reservoir is unlikely. The timing of oil charging is later than that of hydrocarbon generating and expulsion of Liushagang Fm. source rocks and trap formation, which is favorable for oil accumulation in this area. All molecular parameters that are used for tracing oil filling direction decrease with shallower burial depth, which suggests vertical oil migration. The widely occurring faults that penetrate through the source rocks of the Liushagang Fm. may serve as a fine oil charging conduit.  相似文献   

17.
In this research, the solubility of methane in water at presence of β-cyclodextrin (CD), sodium dodecyl sulfate (SDS), and multiwall carbon nanotubes (NTs) have been investigated. The tests were performed at the pressures 3 and 5 bars and temperatures of 1–3°C. For any solution, data of vessel pressure versus time and the total absorption capacity were collected. NTs were dispersed in water by using SDS solution with a concentration of 1 wt% and applying ultrasonic agitation for 25 min. Addition of 0.5 wt% cyclodextrin increased the capacity of methane absorption as much as 14.63% at temperature 1°C and primary pressure of 3 bar. Dissolution capacity increased up to 5.26% by using NT along with SDS at the pressure of 5 bar and low temperatures. Simultaneous usage of CD, SDS, and NT (the solution containing 1 wt% CD, 0.1 wt% SDS, and 1 wt% NT) had the highest effect on the increase of amount and rate of dissolution. The amount of dissolution increases for this solution was 14.63% at temperature 1°C and the primary pressure 3 bar. Utilization of CD, SDS, and NT and their mixture improved the initial dissolution rate of methane at low temperatures.  相似文献   

18.
Synergy was revealed in the action of binary mixtures of heavy metal chelates with N,N,N′,N′-tetrasubstituted p-phenylenediamines in the initiated oxidation of model hydrocarbon ethylbenzene. The value of the synergistic effect (SE), defined as SE = (W add/W mix) ? 1, where W mix and W add are the initial rates of oxygen uptake as obtained experimentally and calculated on the assumption of the additive action of the mixture components, respectively, increases with a decrease in the half-wave potential of the one-electron electrochemical oxidation E 1 2/ox of both chelates and tertiary diamines.  相似文献   

19.
The study of the chlorite coatings always attracts scholars in China and other countries because the chlorite coatings play an important role in the preservation of residual primary pores in sandstone reservoirs.At present,the study of the origin and the controlling factors is relatively few.The occurrence,time of formation,genesis,controlling factors,and the mechanism of chlorite coatings inhibiting quartz overgrowths were studied in detail with thin section and SEM analysis.Samples were from the sandstone reservoirs of the T3x Group in the Baojie area,the transitional zone from the middle to the south of Sichuan Basin.The results indicate that the chlorite coatings on the walls of the pore spaces are oriented perpendicular to grain surfaces in the form of isopachous(even-thickness) grain-coating,while the chlorite coatings at the contacts between adjacent detrital grains are arranged with a preferred orientation tangential to the surface of detrital grains.The chlorite coatings were formed in the eogenetic stage.They were formed by recrystallization of Fe-rich clay films during the syndepositional period,and chlorite cements would be recrystallized after the coatings’ formation.The formation of chlorite coatings was mainly controlled by the depositional environment,provenance conditions,and diagenetic environment.The presence of chlorite coatings could result in the preservation of primary pores in deeply buried sandstone reservoirs by effectively inhibiting quartz overgrowths and the development of compaction and pressure solution.  相似文献   

20.
Polymer of the acrylate of a mixture of three different alcohols, decyl alcohol, dodecyl alcohol, and myristyl alcohol, and the respective homopolymers, poly(decylacrylate), poly(dodecylacrylate), and poly(myristylacrylate), were synthesized, characterized, and evaluated for their performances (oil thickening and pour point depression property) as lube oil additive. The viscosity measurements of the synthesized polymers in the toluene solution at 313 K were performed and compared.  相似文献   

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