Airplane materials compatibility with blends of fossil kerosene JET A1 with biokerosenes from babassu, palm kernel and coconut oils

The aviation companies are facing some problems that argue in favor of biofuels: Rising cost of traditional fuel: from 0.71 USD/gallon in May 2003 to 3.09 USD/gallon in January 2012. Environmental concerns: direct emissions from aviation account for about 3 % of the EU’s total greenhouse gas emissions. The International Civil Aviation Organization (ICAO) forecasts that by 2050 they could grow by a further 300-700 %. On December 20th 2006 the European Commission approved a law proposal to include the civil aviation sector in the European market of carbon dioxide emission rights (European Union Emissions Trading System, EUETS)

Blends of babassu, palm kernal and coconut mame with fossil kerosene: low carbon number methyl esters as a possible source for renewable jet fuel

Three different oils: babassu, coconut and palm kernel have been transesterified with methanol. The fatty acid methyl esters (FAME) have been subjected to vacuum fractional distillation, and the low boiling point fractions have been blended with fossil kerosene at three different proportions: 5, 10 and 20% vol.

Blends of babassu, palm kernel and coconut fame with fossil kerosene. Technical aspects of low carbon number methyl esters as a possible source for renewable jet fuel

State of the Art. Process and Distillation. Fuel Characterization. Fuel Compatibility Tests

Bifurcation diagrams for polymer blends with diffuse interfaces in confined and adaptive geometries

Dynamics of binary mixtures such as polymer blends, and fluids near the critical point, is described by the model-H, which couples momentum transport and diffusion of the components [1]. We present an extended version of the model-H that allows to study the combined effect of phase separation in a polymer blend and surface structuring of the film itself [2]. We apply it to analyze the stability of vertically stratified base states on extended films of polymer blends and show that convective transport leads to new mechanisms of instability as compared to the simpler diffusive case described by the Cahn- Hilliard model [3, 4]. We carry out this analysis for realistic parameters of polymer blends used in experimental setups such as PS/PVME. However, geometrically more complicated states involving lateral structuring, strong deflections of the free surface, oblique diffuse interfaces, checkerboard modes, or droplets of a component above of the other are possible at critical composition solving the Cahn Hilliard equation in the static limit for rectangular domains [5, 6] or with deformable free surfaces [6]. We extend these results for off-critical compositions, since balanced overall composition in experiments are unusual. In particular, we study steady nonlinear solutions of the Cahn-Hilliard equation for bidimensional layers with fixed geometry and deformable free surface. Furthermore we distinguished the cases with and without energetic bias at the free surface. We present bifurcation diagrams for off-critical films of polymer blends with free surfaces, showing their free energy, and the L2-norms of surface deflection and the concentration field, as a function of lateral domain size and mean composition. Simultaneously, we look at spatial dependent profiles of the height and concentration. To treat the problem of films with arbitrary surface deflections our calculations are based on minimizing the free energy functional at given composition and geometric constraints using a variational approach based on the Cahn-Hilliard equation. The problem is solved numerically using the finite element method (FEM).

Long Term Performance Study of a Direct Methanol Fuel Cell Fed with Alcohol Blends

The use of alcohol blends in direct alcohol fuel cells may be a more environmentally friendly and less toxic alternative to the use of methanol alone in direct methanol fuel cells. This paper assesses the behaviour of a direct methanol fuel cell fed with aqueous methanol, aqueous ethanol and aqueous methanol/ethanol blends in a long term experimental study followed by modelling of polarization curves. Fuel cell performance is seen to decrease as the ethanol content rises, and subsequent operation with aqueous methanol only partly reverts this loss of performance. It seems that the difference in the oxidation rate of these alcohols may not be the only factor affecting fuel cell performance.

Airplane materials compatibility with blends of fossil kerosene jet a1 with biokerosenes from babassu, palm kernel and coconut oils

El desarrollo de bioqueroseno de diferentes orígenes y su uso creciente, hacen necesario el estudio de la compatibilidad estos nuevos combustibles con los materiales y recubrimientos con los que se encuentra en contacto. Por tanto, el presente proyecto estudia la compatibilidad de los bioquerosenos mezclados en diferentes proporciones con queroseno mineral, para evaluar posteriormente su compatibilidad con diferentes polímeros y composites presentes en la estructura de un avión.Currently there is a big interest to increase the sources of alternative fuels for aviation to get a reduction of their carbon footprint and the deep energetic dependence from fossil fuels of different countries. Although there are studies about how to produce this alternative fuel and how to accomplish the standards for a good performance in the aircraft turbines, there are no studies about how these fuels could affect the different materials of airplanes. In this context this work describes the compatibility of biokerosene blends of coconut, babassu and palm kernel with commercial Jet A-1 testing airplane polymeric materials, metals and composites. As a conclusion, all material samples show a good compatibility with the fuel blends tested.

Selective response of ternary complex factor Sap1a to different mitogen-activated protein kinase subgroups.

Mitogenic and stres signals results in the activation of extracellular signal-regulated kinases (ERKs) and stress-activated protein kinase/c-Jun N-terminal kinases (SAPK/JNKs), respectively, which are two subgroups of the mitogen-activated protein kinases. A nuclear target of mitogen-activated protein (MAP) kinases is the ternary complex factor Elk-1, which underlies its involvement in the regulation of c-fos gene expression by mitogenic and stress signals. A second ternary complex factor, Sap1a, is coexpressed with Elk-1 in several cell types and shares attributes of Elk-1, the significance of which is not clear. Here we show that Sap1a is phosphorylated efficiently by ERKs but not by SAPK/JNKs. Serum response factor-dependent ternary complex formation by Sap1a is stimulated by ERK phosphorylation but not by SAPK/JNKs. Moreover, Sap1a-mediated transcription is activated by mitogenic signals but not by cell stress. These results suggest that Sap1a and Elk-1 have distinct physiological functions.

Discrimination among pheromone component blends by interneurons in male antennal lobes of two populations of the turnip moth, Agrotis segetum.

A difference in female pheromone production and male behavioral response has previously been found in two populations of the turnip moth, Agrotis segetum, originating from Sweden and Zimbabwe, respectively. In this study, we investigated the pheromone response of antennal lobe interneurons of males of the two populations by intracellular recordings, stimulating with single pheromone components and various inter- and intra-populational pheromone blends. Three major physiological types of antennal lobe neurons were established in the two populations according to their responses to different stimuli. One type responded broadly to almost all the stimuli tested. The second type responded selectively to some of the single components and blends. The third type did not respond to any single components but did respond to certain blends. Furthermore, some neurons of the second and third type recognized strain specific differences in ratios between pheromone components. Both projection neurons and local interneurons were found among these three types. Two pheromone responding bilateral projection neurons are reported for the first time in this paper.

GE models and algorithms for condensed phase equilibrium data regression in ternary systems: limitations and proposals

Phase equilibrium data regression is an unavoidable task necessary to obtain the appropriate values for any model to be used in separation equipment design for chemical process simulation and optimization. The accuracy of this process depends on different factors such as the experimental data quality, the selected model and the calculation algorithm. The present paper summarizes the results and conclusions achieved in our research on the capabilities and limitations of the existing GE models and about strategies that can be included in the correlation algorithms to improve the convergence and avoid inconsistencies. The NRTL model has been selected as a representative local composition model. New capabilities of this model, but also several relevant limitations, have been identified and some examples of the application of a modified NRTL equation have been discussed. Furthermore, a regression algorithm has been developed that allows for the advisable simultaneous regression of all the condensed phase equilibrium regions that are present in ternary systems at constant T and P. It includes specific strategies designed to avoid some of the pitfalls frequently found in commercial regression tools for phase equilibrium calculations. Most of the proposed strategies are based on the geometrical interpretation of the lowest common tangent plane equilibrium criterion, which allows an unambiguous comprehension of the behavior of the mixtures. The paper aims to show all the work as a whole in order to reveal the necessary efforts that must be devoted to overcome the difficulties that still exist in the phase equilibrium data regression problem.

Correlation of the liquid–liquid equilibrium data for specific ternary systems with one or two partially miscible binary subsystems

This paper presents the results of a liquid–liquid equilibrium data correlation for 11 ternary systems which have not been previously fitted using the NRTL model or, when they have, the results presented in the literature are inconsistent with the experimental behavior of the system. These ternary systems include mixtures with one or two partially miscible pairs. During the correlation process, new restrictions were imposed on the values for the NRTL binary parameters to ensure correct prediction of the total or partial miscibility for the binary pairs involved. In addition, topological concepts related to the Gibbs stability test have been applied in order to validate the results in the whole range of compositions.

Modelling liquid–liquid equilibria for island type ternary systems

Closed miscibility gaps in ternary liquid mixtures, at constant temperature and pressure, are obtained if phase separations occur only in the ternary region, whilst all binary mixtures involved in the system are completely miscible. This type of behaviour, although not very frequent, has been observed for a certain number of systems. Nevertheless, we have found no information about the applicability of the common activity coefficient models, as NRTL and UNIQUAC, for these types of ternary systems. Moreover, any of the island type systems published in the most common liquid–liquid equilibrium data collections, are correlated with any model. In this paper, the applicability of the NRTL equation to model the LLE of island type systems is assessed using topological concepts related to the Gibbs stability test. A first attempt to correlate experimental LLE data for two island type ternary systems is also presented.

Geometrical study of the three-dimensional temperature–composition diagrams. An important aid to understand the behavior of the liquid–vapour equilibrium in ternary systems

In this work the usefulness of qualitatively studying and drawing three-dimensional temperature–composition diagrams for ternary systems is pointed out to understand and interpret the particular behavior of the liquid–vapour equilibrium of non-ideal ternary systems. Several examples have been used in order to highlight the interest and the possibilities of this tool, which should be an interesting support not only for lecturers, but also for researchers interested in experimental equilibrium data determination.

Solubility, Density, Refractive Index, and Viscosity for the Polyhydric Alcohol + CsBr + H2O Ternary Systems at Different Temperatures

The solubility, density, refractive index, and viscosity data for the ethylene glycol + CsBr + H2O, 1,2-propanediol + CsBr + H2O, and glycerin + CsBr + H2O ternary systems have been determined at (288.15, 298.15, and 308.15) K. In all cases, the solubility of CsBr in aqueous solutions was decreased significantly due to the presence of polyhydric alcohol. The liquid–solid equilibrium experimental data were correlated using the NRTL (nonrandom two-liquid) activity coefficient model, considering nondissociation of the dissolved salt in the liquid phase, and new interaction parameters were estimated. The mean deviations between calculated and experimental compositions were low, showing the good descriptive quality and applicability of the NRTL model. The refractive indices, densities, and viscosities for the unsaturated solutions of the three ternary systems have also been measured at three temperatures. Values for all of the properties were correlated with the salt concentrations and proportions of polyhydric alcohol in the solutions.

Phase equilibria of the water + 1-butanol + toluene ternary system at 101.3 kPa

Isobaric vapour–liquid and vapour–liquid–liquid equilibrium data for the water + 1-butanol + toluene ternary system were measured at 101.3 kPa with a modified VLE 602 Fischer apparatus. In addition, the liquid–liquid equilibrium data at 313.15 K were measured and compared with data from other authors at different temperatures. The system exhibits a ternary heterogeneous azeotrope whose temperature and composition have been determined by interpolation. The thermodynamic consistency of the experimental vapour–liquid and vapour–liquid–liquid data was checked by means of the Wisniak’s Li/Wi consistency test. Moreover, the vapour–liquid and the liquid–liquid equilibrium correlation for the ternary system with NRTL and UNIQUAC models, together with the prediction made with the UNIFAC model, were studied and discussed.

Disintegrability under composting conditions of plasticized PLA–PHB blends

The disintegration under composting conditions of films based on poly(lactic acid)–poly(hydroxybutyrate) (PLA–PHB) blends and intended for food packaging was studied. Two different plasticizers, poly(ethylene glycol) (PEG) and acetyl-tri-n-butyl citrate (ATBC), were used to limit the inherent brittleness of both biopolymers. Neat PLA, plasticized PLA and PLA–PHB films were processed by melt-blending and compression molding and they were further treated under composting conditions in a laboratory-scale test at 58 ± 2 °C. Disintegration levels were evaluated by monitoring their weight loss at different times: 0, 7, 14, 21 and 28 days. Morphological changes in all formulations were followed by optical and scanning electron microscopy (SEM). The influence of plasticizers on the disintegration of PLA and PLA–PHB blends was studied by evaluating their thermal and nanomechanical properties by thermogravimetric analysis (TGA) and the nanoindentation technique, respectively. Meanwhile, structural changes were followed by Fourier transformed infrared spectroscopy (FTIR). The ability of PHB to act as nucleating agent in PLA–PHB blends slowed down the PLA disintegration, while plasticizers speeded it up. The relationship between the mesolactide to lactide forms of PLA was calculated with a Pyrolysis–Gas Chromatography–Mass Spectrometry device (Py–GC/MS), revealing that the mesolactide form increased during composting.