Among the various properties exhibited by ionic liquids (ILs)—especially those based on the imidazolium cation—their inherent ionic patterns, very low vapour pressure and pronounced self-organization in the solid, liquid and even in the gas phase are particularly interesting since this allows the use of these fluids as alternative and complementary media to classical organic solvents and water in many applications. Hence, reaction paths that involve charge-separated intermediates or transition states are accelerated—by lowering the activation barrier—in the presence of ILs when compared with those performed in classical organic solvents. It is also possible, for example, to observe, by electrochemical methods, transient species (ionic and radical) that are otherwise undetectible in water or in molecular organic solvents and to investigate the interactions and behaviour of molecular, biological and macromolecular species in solution using physical and chemical methods which require special conditions such as high-vacuum, and which have been traditionally limited to solid state chemistry.
The use of biomass as raw-material for obtaining chemicals, polymers and fuels is emerging as a clever alternative solution for the increasing energy demand, environmental awareness and petroleum shortage. In this work, some attempts in order to develop catalytic systems suitable for triglyceride transformation into fuels, polymers and intermediates are reviewed
1 April 2012 in Journal of the Brazilian Chemical Society
An analytical method using high performance liquid chromatography with UV detection (HPLC‑UV) (method A) was used for simultaneous determination of total amounts of triacylglycerides, diacylglycerides, monoacylglycerides and fatty acid methyl esters in alcoholysis of different oil (cotton, canola, sunflower, corn and soybean) samples. Analyses were carried out at 40 °C for 20 min using a gradient of methanol (MeOH) and 2-propanol-hexane 5:4 (v/v) (PrHex): 100% of MeOH in 0 min, 50% of MeOH and 50% of PrHex in 10 min maintained with isocratic elution for 10 min. Another HPLC-UV method (method B) with acetonitrile isocratic elution for 34 min was used to determine the fatty acid composition of oils analyzing their methyl ester derivatives. Contents were determined with satisfactory repeatability (relative standard deviation, RSD < 3%), linearity (r² > 0.99) and sensitivity (limit of quantification). Method B was compared with an official gas chromatographic method with flame ionization detection (GC-FID) from American Oil Chemists' Society (AOCS) in the determination of fatty acid methyl esters (FAME) in biodiesel real samples.
This article reviews biochar production and its potential applications across various sectors, including agriculture, environmental remediation, and energy storage. It emphasizes the critical role of feedstock source and process parameters, such as residence time, heating rate, and temperature, in determining biochar’s properties. Although extensive research has been conducted on the physical and chemical properties of biochar, there remains a significant gap in evaluating its practical applications. This paper emphasizes the role of Multi-Criteria Decision Analysis (MCDA) as a valuable tool for optimizing both biochar production and its application strategies. By exploring scholarly articles and patents, it offers insights into biochar production techniques, characterization methods, and the importance of process optimization for sustainable and efficient biochar use in real-world scenarios.
8 September 2008 in Magnetic Resonance in Chemistry