Molecular interconversion behaviour in comprehensive two-dimensional gas chromatography

Comprehensive two-dimensional gas chromatography (GC x GC) is shown to provide information on dynamic molecular behaviour (interconversion), with the interconversion process occurring on both columns in the coupled-column experiment. The experiment requires suitable adjustment of both experimental conditions and relative dimensions of each of the columns. In this case, a longer column than normally employed in GC x GC allows sufficient retention duration on the second column, which permits the typical plateau-shape recognised for the interconversion process to be observed. The extent of interconversion depends on prevailing temperature, retention time, and the phase type. Polyethylene glycol-based phases were found to result in high interconversion kinetics, although terephthalic acid-terminated polyethylene glycol had a lesser extent of interconversion. Much less interconversion was seen for phenyl-methylpolysiloxane and cyclodextrin phases. This suggests that for the oximes, interconversion largely occurs in the stationary phase. Examples of different extents of interconversion in both dimensions are shown, including peak coalescence on the first column with little interconversion on the second column

Physical Characterization of Palm Fatty Acid Distillate (PFAD) Blends as Biofuel

Palm oil has been accepted to be used as fuel with the introduction of petroleum diesel and Palm Methyl Ester (PME) in 2014. The high cost is the major drawback of PME. Not only PME is derived from an expensive low Free Fatty Acid (FFA) feedstock, the cost to convert FFA to PME through the process of trans esterification and purification of palm oil fatty acid is also expensive. Alternative feedstock of FFA is palm fatty acid distillate (PFAD). PFAD is a by-product of crude palm oil (CPO) refining. It is inedible and a low price palm oil product making it attractive as a feedstock for biofuel. The high viscosity of PFAD can be reduced by blending it with diesel fuel. Five blends of PFAD and diesel blends with 2%, 4%, 6%, 8% and 10% volumetric ratio were produced in this study. The physical properties of the blends such as density, viscosity, surface tension and flash point were determined and the results were compared to the Malaysian Standard for Diesel Fuel (MS123:2014). The results show that all properties of the blends are within the acceptable value for diesel fuel

Characterization of Annona cherimola mill. Seed oil from Madeira Island: a possible biodiesel feedstock

The possibility of using Annona seed oil as an added value product, namely as a source of biodiesel, is explored. Milled Annona seeds were extracted with hexane at room temperature (72 h) and at solvent boiling point (6 h). Oil content was found to be 25 and 22.4% respec tively. The oil was characterized in terms of lipid compo sition (HPLC–APCI–MS and 13C NMR), resistance to oxidation and acidity index. FAME composition was determined by GC–MS and five major peaks were identi fied. Production of biodiesel from Annona’s seed oil was achieved by base-catalyzed transesterification. Density, viscosity, refraction coefficient, acid value, cold filter plugging point, cloud point and oxidation stability were measured. The iodine value and the ‘‘apparent cetane number’’ were calculated. Density, viscosity, acid value, iodine value, cold filter plugging point and cloud point were within EN14214 specifications and the calculated ‘‘apparent cetane number’’ was also indicative of a suitable product.info:eu-repo/semantics/publishedVersio

On Harmonic Measure Level Curves in K-Domains.

This thesis analyzes the geometry of the level curves of the harmonic measure of an arc (alpha) in the boundary of a k-domain D. In particular, estimates are obtained for the ratio of the distances from a point on a level curve to the boundary arcs (alpha) and (PAR-DIFF)D(FDIAG)(alpha); estimates are also obtained for the relative size of the diameters and lengths of the level curve and of the boundary arc (alpha). Finally, hyperbolic curvature is used to estimate the euclidean curvature of the level curves. Some results concerning the hyperbolic metric in k-domains are also obtained.Ph.D.MathematicsUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/159028/1/8224987.pd

In Situ Trans-Esterification of Residual Oils in Spent Bleaching Clays from Vegetable Oil Refineries

Spent bleaching clays (SBCs) from vegetable oil refineries are industrial wastes. The clays contain large amount of oils (20-25%), which are good feedstock for biodiesels. Non-thermal in situ trans-methylation and trans-ethylation of oils in the SBC from rice bran oil (RBO), crude palm oil (CPO) and palm kernel oil (PKO) are rapid and can be accomplished in minutes with an alkaline catalyst. Thus, the process may possibly be used for large scale preparation of ethyl biodiesel

Prediction Models for Density and Viscosity of Biodiesel and their Effects on Fuel Supply System in CI Engines

Biodiesel is a promising non-toxic and biodegradable alternative fuel used in the transport sector. Nevertheless, the higher viscosity and density of biodiesel poses some acute problems when it is used it in unmodified engine. Taking this into consideration, this study has been focused towards two objectives. The first objective is to identify the effect of temperature on density and viscosity for a variety of biodiesels and also to develop a correlation between density and viscosity for these biodiesels. The second objective is to investigate and quantify the effects of density and viscosity of the biodiesels and their blends on various components of the engine fuel supply system such as fuel pump, fuel filters and fuel injector. To achieve first objective density and viscosity of rapeseed oil biodiesel, corn oil biodiesel and waste oil biodiesel blends (0B, 5B, 10B, 20B, 50B, 75B, and 100B) were tested at different temperatures using EN ISO 3675:1998 and EN ISO 3104:1996 standards. For both density and viscosity new correlations were developed and compared with published literature. A new correlation between biodiesel density and biodiesel viscosity was also developed. The second objective was achieved by using analytical models showing the effects of density and viscosity on the performance of fuel supply system. These effects were quantified over a wide range of engine operating conditions. It can be seen that the higher density and viscosity of biodiesel have a significant impact on the performance of fuel pumps and fuel filters as well as on air-fuel mixing behaviour of compression ignition (CI) engine

LHV Predication Models and LHV Effect on the Performance of CI Engine Running with Biodiesel Blends

The heating value of fuel is one of its most important physical properties, and is used for the design and numerical simulation of combustion processes within internal combustion (IC) engines. Recently, there has been a significant increase in the use of dual fuel and blended fuels in compression ignition (CI) engines. Most of the blended fuels include biodiesel as one of the constituents and hence the objective of this study is to investigate the effect of biodiesel content to lower heating value (LHV) and to develop new LHV prediction models that correlate the LHV with biodiesel fraction, density and viscosity. Furthermore, this study also investigated the effects of the LHV on CI engines performance parameters experimentally. To achieve the above mentioned objectives density, viscosity and LHV of rapeseed oil biodiesel, corn oil biodiesel and waste oil biodiesel at different blend fraction values (B0, B5, B10, B20, B50, B75, and B100, where ‘B5’ denotes a blend of 5% biodiesel and 95% mineral diesel, etc) were measured as per EN ISO 3675:1998, EN ISO 3104:1996 and DIN 51900 standards. The engine experimental work was conducted on a four-cylinder, four -stroke, direct injection (DI) and turbocharged diesel engine by using rapeseed oil and normal diesel blends. Based on the experimental results, models were developed which have the capability to predict the LHV corresponding to different fractions, densities and viscosities of biodiesel. The models are shown to produce consistent results with experimentally measured ones and compared with previous researches’ models. Furthermore the effects of LHV on brake specific fuel consumption (BSFC) and thermal efficiency were analysed and it has been seen that for the neat biodiesel which its LHV is lower by 8% than diesel resulted in an increment of BSFC and thermal efficiency by 18% and 25% respectively

Emission Characteristics of a CI Engine Running with a Range of Biodiesel Feedstocks

Currently, alternative fuels are being investigated in detail for application in compression ignition (CI) engines resulting in exciting potential opportunities to increase energy security and reduce gas emissions. Biodiesel is one of the alternative fuels which is renewable and environmentally friendly and can be used in diesel engines with little or no modifications. The objective of this study is to investigate the effects of biodiesel types and biodiesel fraction on the emission characteristics of a CI engine. The experimental work was carried out on a four-cylinder, four-stroke, direct injection (DI) and turbocharged diesel engine by using biodiesel made from waste oil, rapeseed oil, corn oil and comparing them to normal diesel. The fuels used in the analyses are B10, B20, B50, B100 and neat diesel. The engine was operated over a range of engine speeds. Based on the measured parameters, detailed analyses were carried out on major regulated emissions such as NOx, CO, CO2, and THC. It has been seen that the biodiesel types (sources) do not result in any significant differences in emissions. The results also clearly indicate that the engine running with biodiesel and blends have higher NOx emission by up to 20%. However, the emissions of the CI engine running on neat biodiesel (B100) were reduced by up to 15%, 40% and 30% for CO, CO2 and THC emissions respectively, as compared to diesel fuel at various operating conditions