The present paper reviews existing knowledge with regard to Organic Aerosol (OA) of importance for global climate modelling and defines critical gaps needed to reduce the involved uncertainties. All pieces required for the representation of OA in a global climate model are sketched out with special attention to Secondary Organic Aerosol (SOA): The emission estimates of primary carbonaceous particles and SOA precursor gases are summarized. The up-to-date understanding of the chemical formation and transformation of condensable organic material is outlined. Knowledge on the hygroscopicity of OA and measurements of optical properties of the organic aerosol constituents are summarized. The mechanisms of interactions of OA with clouds and dry and wet removal processes parameterisations in global models are outlined. This information is synthesized to provide a continuous analysis of the flow from the emitted material to the atmosphere up to the point of the climate impact of the produced organic aerosol. The sources of uncertainties at each step of this process are highlighted as areas that require further studies.

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Organic aerosol and global climate modelling: a review

Kinematic viscosity of biodiesel fuel components and related compounds. Influence of compound structure and comparison to petrodiesel fuel components

In a preceding project, functional forms for “short” Helmholtz energy equations of state for typical nonpolar and weakly polar fluids and for typical polar fluids were developed using simultaneous optimization. In this work, the coefficients of these short forms for the equations of state have been fitted for the fluids acetone, carbon monoxide, carbonyl sulfide, decane, hydrogen sulfide, 2-methylbutane (isopentane), 2,2-dimethylpropane (neopentane), 2-methylpentane (isohexane), krypton, nitrous oxide, nonane, sulfur dioxide, toluene, xenon, hexafluoroethane (R-116), 1,1-dichloro-1-fluoroethane (R-141b), 1-chloro-1,1-difluoroethane (R-142b), octafluoropropane (R-218), 1,1,1,3,3-pentafluoropropane (R-245fa), and fluoromethane (R-41). The 12 coefficients of the equations of state were fitted to substance specific data sets. The results show that simultaneously optimized functional forms can be applied to other fluids out of the same class of fluids for which they were optimized without significant loss of a...

Short Fundamental Equations of State for 20 Industrial Fluids

Alcohols have an interesting potential as blending components for diesel fuels because of their capacity to reduce soot formation. Because they have increasing routes for their production from renewable sources, they could contribute toward increasing the renewable fraction of these fuels and, therefore, toward reducing the impact of diesel transportation on the global warming effect. To increase the knowledge about the implications of the use of short- and long-chain alcohols/diesel fuel blends in diesel engines, the stability, lubricity, viscosity, and cold filter plugging point (CFPP) have been tested. Blends of methanol, ethanol, propanol, butanol, and pentanol with diesel fuel have been analyzed at 1, 2.5, 7.7, 17, 50, 75, and 90% in volume [including 95% (v/v) in the case of CFPP]. Results have shown that short-chain alcohols depict poor blending stability and low viscosity (mainly for concentrations of ethanol and propanol in diesel fuel blends beyond 22 and 45%, respectively). A synergistic effect...

Stability, Lubricity, Viscosity, and Cold-Flow Properties of Alcohol−Diesel Blends

Ionic liquids (ILs) and deep eutectic solvents (DESs) have been suggested as eco-friendly alternatives to organic solvents. A trace amount of water is often unavoidable as impurity, and water is also added on purpose to reduce their problematically high viscosity and lower their high price. Understanding the distinct effects of water on the properties of ILs/DESs is highly important. In this review, we collect published experimental and theoretical results for IL/DES–H2O systems at varied water concentrations and analyze them. Results from mechanistic studies, thermodynamic modelling and advanced experiments are collected and critically discussed. Six commonly studied IL/DES–H2O systems were selected to map experimental observations onto microscopic results obtained in mechanistic studies. A great variety of distinct contours of the excess properties can be observed over the entire compositional range, indicating that the properties of IL/DES–H2O systems are highly unpredictable. Mechanistic studies clearly demonstrate that the added H2O rapidly changes the heterogeneous 3D structures of pure ILs/DESs, leading to very different properties and behaviour. There are similarities between aqueous electrolytes and IL/DES solutions but the bulky and asymmetric organic cations in ILs/DESs do not conform to the standard salt dissolution and hydration concepts. Thermodynamic modelling previously assumes ILs/DESs to be either a neutral ion-pair or completely dissociated ions, neglecting specific ion hydration effects. A new conceptual framework is suggested for thermodynamic modelling of IL/DES–H2O binary systems to enable new technologies for their practical applications.

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The peculiar effect of water on ionic liquids and deep eutectic solvents

Excess volume, changes of refractive index and surface tension of binary 1,2-ethanediol + 1-propanol or 1-butanol mixtures at several temperatures

Experimental measurement of the hygroscopic grade on eight imidazolium based ionic liquids

Dynamic viscosity and specific electrical conductivity on three binary systems of 1-alkyl-3-methyl imidazolium tetrafluoroborate [CnMIM][BF4] with water covering all ranges of concentrations are presented. Viscosity was measured at 15.0 °C, 25.0 °C, 35.0 °C, and 45.0 °C, while conductivity was measured at those four temperatures for equimolar mixtures only and at 25 °C over the whole composition range. The alkyl chains of the ILs used were ethyl [EMIM][BF4], butyl [BMIM][BF4], and hexyl [HMIM][BF4]. Note that [HMIM][BF4] is only partially miscible in water at the studied temperatures and atmospheric pressure. Viscosity deviations and molar conductivity were derived from experimental data and fitted to suitable equations. Experimental data were also compared with those previously published, and a good agreement was observed. Transport properties were discussed in terms of Walden’s rule, which is partially correct. This paper complements one recently published by us, where density and surface tension at 25 ...

Electrical Conductivity and Viscosity of Aqueous Binary Mixtures of 1-Alkyl-3-methyl Imidazolium Tetrafluoroborate at Four Temperatures†

Thermophysical properties of four binary dimethyl carbonate + 1-alcohol systems at 288.15-313.15 K

Surface tension and refractive index for binary mixtures of {octane + ethanol, + 1-propanol, + 1-butanol, + 1-pentanol, + 1-hexanol, + 1-heptanol, and + 1-octanol}, and density for {octane + ethanol} have been measured at T = 298.15 K for the whole composition range. From the experimental data we extract excess molar volumes, surface tension deviations, and changes of refractive index. All these experimental data are compared among them and with previous results of the binary mixtures hexane + 1-alkanol and dibutyl ether + 1-alkanol. Also we compare our present results with other published data when available.

Luisa Segade

Papers

Excess volume, changes of refractive index and surface tension of binary 1,2-ethanediol + 1-propanol or 1-butanol mixtures at several temperatures

Experimental measurement of the hygroscopic grade on eight imidazolium based ionic liquids

Electrical Conductivity and Viscosity of Aqueous Binary Mixtures of 1-Alkyl-3-methyl Imidazolium Tetrafluoroborate at Four Temperatures†

Thermophysical properties of four binary dimethyl carbonate + 1-alcohol systems at 288.15-313.15 K

Density, Surface Tension, and Refractive Index of Octane + 1-Alkanol Mixtures at T = 298.15 K