[Show abstract][Hide abstract] ABSTRACT: It is inevitable for the soot particles from engine fuel to contaminate the lubricating oil, which may increase the viscosity of lubricating oil, and consequently influence the lubricity and usability of engine. In this paper, the surface properties of biomass fuel soot (BS) and diesel soot (DS) were contrastively investigated by means of Fourier infrared spectrometer, X-ray photoelectron spectroscopy, full-automatic micropore physisorption and chemisorption analyzer, optical contact angle/interface tension meter and Zeta potentiostat in order to study the effect of BS and DS particles on viscosity of liquid paraffin (LP, simulant of base oil for lubricating oil), and discuss the mechanism of influence of soot surface properties on the viscosity. Results showed that the relative viscosity increased by exponential function with increasing soot content at 40℃. The relative viscosity of oil contaminated by DS was higher than that of BS in case of the same soot contents. The oil contaminated with high concentration soot had the advantage of clearly identified shear thinning behavior, which was more severely in LP contaminated by DS. The main surface elements of BS and DS were carbon and oxygen. The surface oxygen content of DS was less than that of BS. There were some O-containing functional groups on the surfaces of BS and DS. The surface property analysis showed that the specific surface area and the surface energy of DS were higher than those of BS. The lipophilicity of DS was less than that of BS. The DS was apt to agglomerate into larger agglomeration particles in LP, which was the main reason for the fact of DS affecting LP viscosity more severely compared with BS.
[Show abstract][Hide abstract] ABSTRACT: A biomass oil/diesel blend was prepared using an emulsion method and combusted in a diesel engine. An injector was then removed and the morphology, composition, and structure of the carbonaceous deposits on the pintle-type nozzle were characterized using a combination of HRTEM, SEM/EDAX, Raman and XRD. Results showed that the carbon deposition of the emulsified fuel with high crystallinity was greater than that of diesel. The agglomerated particulate diameters of the deposited carbon from diesel and emulsified fuel were approximately 10–30 μm and 50 μm, respectively. The carbon deposition mechanism from the emulsified fuel was attributed to the high oxygen content of the groups leading to increased polymerization and subsequent condensation on the nozzle surfaces that was then carbonised.
Full-text · Article · Jul 2015 · Tribology International
[Show abstract][Hide abstract] ABSTRACT: Soot dispersibility is an important performance index of diesel engine oil. The dispersion performance of biofuel soot (BS) and 0# diesel soot (DS) in liquid paraffin (LP) and the influence of polyisobutylene succinimide dispersant (T154) were investigated by means of viscosity, spot experiment and particle size distribution. The dispersion mechanisms of BS and DS were investigated by means of X-ray photoelectron spectroscopy and Fourier infrared spectrometer. The surface of BS and DS contained some O-containing functional groups and the oxygen content of BS was higher than that of DS. The effect of oil thickening by DS was greater than that by BS. T154 has a good effect on dispersing BS and DS in LP. The influence of T154 on the BS and LP dispersing system was better than the DS and LP dispersing system. T154 could also be used as a dispersant to disperse BS into lubricating oil. Because of BS surface with O-containing acid groups, such as carboxyl group, and phenolic hydroxyl, it could adsorb T154 by the acid-base reaction with succinimide of dispersant. At the same time, because of BS surface with polar groups, it could adsorb T154 through forming hydrogen bonds with the giving electrons unit of N-H.
[Show abstract][Hide abstract] ABSTRACT: A four-ball tribological test was used to investigate the effects of a TiF3 catalyst on the tribological behaviors of biofuel soot (BS)-contaminated liquid paraffin (LP). The effects of load and rotational speed were studied as well. Scanning electron microscopy with energy-dispersive spectroscopy and X-ray photoelectron spectroscopy were conducted to investigate surface element content and chemical valence state, respectively. Results showed that the extreme pressure properties of BS-contaminated LP were all promoted with or without the presence of 0.5 wt% TiF3. The TiF3 catalyst material significantly contributed to the antiwear and the antifriction properties of LP with or without BS contamination. These results were caused by the decomposition of the TiF3 catalyst into TiO2 and fluoride (FeF2) which improved the lubricity.
Full-text · Article · Sep 2014 · Tribology International
[Show abstract][Hide abstract] ABSTRACT: Export Date: 3 October 2013, Source: Scopus, CODEN: WEARA, doi: 10.1016/j.wear.2013.06.003, Language of Original Document: English, Correspondence Address: Hu, X.; Institute of Tribology, Hefei University of Technology, Hefei 230009, China; email: email@example.com, Funding Details: 51275143, NSFC, National Natural Science Foundation of China, References: Calabria, R., Chiariello, F., Massoli, P., Combustion fundamentals of pyrolysis oil based fuels (2007) Experimental Thermal and Fluid Science, 31, pp. 413-420;
[Show abstract][Hide abstract] ABSTRACT: Biomass-oil soot (BS) particles were characterized by a range of analytical techniques. A comparative analysis with commercial carbon black (CB), a surrogate for diesel soot particles, was carried out. The experimental results showed that the morphologies of BS and CB particles were both spherical, with average diameters of 50 and 40 nm, respectively. There were only a few differences between the elemental composition of BS and CB. The groups (CO, OCO and COC) were presented on the surfaces of CB and BS. Moreover, it was also found that COH group was appeared on the surface of BS. BS contained more acidic and basic sites than CB, which was ascribed to the complex mixtures of biomass oil. Both BS and CB had virtually indistinguishable perturbed graphitic or turbostratic internal structures. Thus, CB can be a potential alternative to evaluate the aggregation and tribological behavior of BS in lubricating oils.