Experimental investigation of power output and soot emission for micro-emulsification diesel oil using for vehicle

The micro-emulsification diesel oil with water dopant of 5%,10% and 15% was prepared using the NAA micro-emulsification compound developed by the authors.The engine bench testing was carried out on the 485QB diesel engine.From the testing results of velocity,loading and exhaust gas,it can be seen that the power decreases and the fuel consumption increases using the micro-emulsification diesel oil.But based on the actual fuel consumption,the use of emulsification diesel with water dopant of 10% can get the effect of oil saving;while with water dopant of more than 15%,it doesn't work evidently.The investigation shows that using the micro-emulsification diesel oil,we can reduce the exhaust gas pollution and receive better environment benefit.     

Study of perovskite‐type oxides and their supported Ag derivatives for catalytic oxidation of diesel soot

A series of perovskite‐type oxides and derived Ag catalysts were prepared, and characterized by N₂‐adsorption, X‐ray diffraction and X‐ray photoelectron spectroscopy. The influences of pretreatment and Ag loading on catalytic activity for diesel soot oxidation were also investigated. Prereduction resulted in a decrease in catalytic activity. An increase in activity with Ag addition was observed, especially with more than 5% Ag loading. This catalyst could be a promising candidate for the catalytic elimination of diesel soot. © 2002 Society of Chemical Industry     

The effect of the contact between platinum and soot particles on the catalytic oxidation of soot deposits on a diesel particle filter

Experiments were performed with two model soot aerosols brought into different forms of contact with Pt aerosol particles, to investigate the effectiveness of this contact in lowering the catalytic soot oxidation temperature. The contact was either generated between individual particles in the aerosol state (Pt-doped soot to simulate a fuel borne catalyst), or by sequential or simultaneous deposition of separately generated soot and Pt aerosols onto a sintered metal filter. (Formation of a soot cake on previously deposited Pt aerosol would simulate a catalyst coated diesel particle filter.) The catalytic activity was determined in all cases from temperature ramped oxidation in air of the filtered particles, and defined as the 50% conversion temperature.

It was found that Pt-doped soot and simultaneously filtered aerosols were both equally effective in reducing the oxidation temperature by up to 140–250 °C for the spark discharge soot (with 3–47 wt% Pt concentration in the soot cake), and by up to 140 °C for the pyrolysis soot (3 wt% Pt). Conversely, the deposition of a thin soot layer of 5–10 μm thickness onto Pt, or vice versa, produced only a slight temperature reduction on the order of about 13–42 °C. These results suggest that the distance between soot and Pt particles plays a key role in promoting an effective oxidation on the filter, which is consistent with the role of Pt particles as local generators of activated oxygen.     

The Behavior of Diluted Sooted Oils in Lubricated Contacts

An increase in the engine lubricant soot levels has recently been noticed. This increase in soot content of lubricating oils has caused a series of problems in the overall performance of the engine. In a practical context, sooted oils consist of carbonaceous matter suspended in engine oil forming a system commonly known as a colloid sol. The objective of this paper is to better understand the mechanism of action of oil containing soot particles in the lubricated contacts and to identify how the colloidal nature of the sooted oil is related to its performance. This study has shown by means of ultra-thin film interferometry and image analysis techniques that soot colloid particles are entrained in the contact inlet where they can influence the friction and wear characteristics of the base stock. This study shows that soot primary particles are entrained into the contact at slow speeds, affecting the film characteristics of clean engine oils. This entrainment of particles is more pronounced at high temperatures.     

A comparative study of the formation of aromatics in rich methane flames doped by unsaturated compounds

For a better modeling of the importance of the different channels leading to the first aromatic ring, we have compared the structures of laminar rich premixed methane flames doped with several unsaturated hydrocarbons: allene and propyne, because they are precursors of propargyl radicals which are well known as having an important role in forming benzene, 1,3-butadiene to put in evidence a possible production of benzene due to reactions of C₄ compounds, and, finally, cyclopentene which is a source of cyclopentadienyl methylene radicals which in turn are expected to easily isomerizes to give benzene. These flames have been stabilized on a burner at a pressure of 6.7 kPa (50 Torr) using argon as dilutant, for equivalence ratios (?) from 1.55 to 1.79. A unique mechanism, including the formation and decomposition of benzene and toluene, has been used to model the oxidation of allene, propyne, 1,3-butadiene and cyclopentene. The main reaction pathways of aromatics formation have been derived from reaction rate and sensitivity analyses and have been compared for the three types of additives. These combined analyses and comparisons can only been performed when a unique mechanism is available for all the studied additives.     

Nanostructure and reactivity of carbon particles from co-pyrolysis of biodiesel surrogate methyl octanoate blended with n-butanol

This paper presents nanostructure and reactivity of carbon particles (soot) from co-pyrolysis of biodiesel surrogate methyl octanoate blended with n-butanol at temperatures from 1023 K to 1223 K in a quartz tube flow reactor, as n-butanol concentration increases from 0 to 50% (mole fraction) in the mixed fuels. The soot structure was characterized by low and high resolution transmission electron spectroscopy (LRTEM and HRTEM) and X-ray diffraction (XRD). The soot reactivity was investigated by thermogravimetric analyzer (TGA). When the pyrolysis temperature increased, as well as the rise of n-butanol addition, soot presented the higher degree of graphitization with the larger fringe length and lower fringe tortuosity. TGA results revealed that the higher amount addition of n-butanol can induce the formations of less reactive soot, and soot yielded at lower temperatures was more reactive than that at high temperatures. In addition, the high correlations between soot reactivity with its nanostructure were given in details.     

Pt–Ce-soot generated from fuel-borne catalysts: soot oxidation mechanism

Soot containing Ce-, Pt-, Pt–Ce-, Fe-, and Cu-fuel-borne catalysts is generated in a diesel engine, is characterised by XRD, and studied in oxidation with O₂ and NO + O₂ under various reaction conditions. Fe-, Pt–Ce- and Ce-soot are oxidised at lower temperature with O₂, compared with Pt-soot, and the opposite trend is observed with NO + O₂. NO is oxidised to NO₂ more efficiently over Pt-soot and decreased the soot oxidation temperature by about 150 °C, compared with Ce-, Fe- or Pt–Ce-soot. On the other hand, NO₂ is most efficiently utilised over the Pt–Ce- and Ce-soot. The soot oxidation under the different feed gas conditions demonstrates that nitrate species are involved in the oxidation of Ce- and Pt–Ce-soot. The oxidation species with the decreasing order of activity are: (1) nitrates, (2) NO₂, (3) lattice oxygen, and (4) gas-phase oxygen. All the above species are involved in the oxidation of Pt–Ce-soot.     

吹灰器在直接管式加热炉上的混合使用

在管式直接加热炉上混合使用声波吹灰器和气动旋转式吹灰器,分别利用其优点,使其达到良好的吹灰效果,满足使用要求。     

Effect of diesel soot on lubricant oil viscosity

Soot related lubricant oil thickening is a primary concern for heavy-duty diesel engines. Engines which produce a relatively low level of particulate matter in exhaust emissions show a significant level of soot contamination in the lubricant. This contamination results in lubricant breakdown. The soot contaminates the lubricant and changes the chemical properties resulting in the lubricant ceasing to perform its functions. This causes an increase in viscosity of the engine oil causing pumpability problems. Hence, it is necessary to study the effects of soot and lubricant oil additives and their interactions on engine oil viscosity.Statistically designed experiments were developed to study the effect of soot contamination on engine oil viscosity. The oil samples used for the study differed in the base stock, dispersant level, and Zinc Dithiophosphate (ZDP) level. These three variables were formulated at two levels: Low (−1) and High (1), which resulted in a 2³ matrix (8 oil blends). Soot was considered as a variable at three levels: low/0% weight (−1), medium/2% by weight (0), and high/4% by weight (1). This resulted in 24 oil samples, and soot at three levels helped in determining the non-linear effect of soot on oil viscosity.Experiments were conducted at 40 and 90 °C to study the effect of the various factors on viscosity with temperature variation. The results showed that viscosity of the oil samples increased with increase in soot at both 40 and 90 °C. The analysis indicated a nonlinear behavior of viscosity as the amount of soot increased at 40 °C, whereas a linear variation at 90 °C.The results obtained were analyzed using the general linear model (GLM) procedure of the statistical analysis system (SAS) package to determine the significance of variables on viscosity. The statistical analysis system also highlighted the significance of various interactions among the variables on viscosity. The statistical analysis results at 40 and 90 °C showed that the effect of base stock and ZDP levels were negligible at 40 °C, whereas the dispersant level and soot level influenced the viscosity of the oil samples at both temperatures.     

Nanostructure and reactivity of soot from biofuel 2,5-dimethylfuran pyrolysis with CO2 additions

This paper investigated the nanostructure and oxidation reactivity of soot generated from biofuel 2,5-dimethylfuran pyrolysis with different CO₂ additions and different temperatures in a quartz tube flow reactor. The morphology and nanostructure of soot samples were characterized by a low and a high resolution transmission electron spectroscopy (TEM and HRTEM) and an X-ray diffraction (XRD). The oxidation reactivity of these samples was explored by a thermogravimetric analyzer (TGA). Different soot samples were collected in the tail of the tube. With the increase of temperature, the soot showed a smaller mean particle diameter, a longer fringe length, and a lower fringe tortuosity, as well as a higher degree of graphization. However, the variation of soot nanostructures resulting from different CO₂ additions was not linear. Compared with 0%, 50%, and 100% CO₂ additions at one fixed temperature, the soot collected from the 10% CO₂ addition has the highest degree of graphization and crystallization. At three temperatures of 1173 K, 1223 K, and 1273 K, the mean values of fringe length distribution displayed a ranking of 10% CO₂>100% CO₂>50% CO₂ while the mean particle diameters showed the same order. Furthermore, the oxidation reactivity of different soot samples decreased in the ranking of 50% CO₂ addition>100% CO₂ addition>10% CO₂ addition, which was equal to the ranking of mean values of fringe tortuosity distribution. The result further confirmed the close relationship between soot nanostructure and oxidation reactivity.