The demand for a new solvent to treat oilsands was behind the purpose of this project; molecular dynamics simulation was used in this study. Supercritical water, supercritical carbon dioxide and other selected organic solvents in their supercritical state were studied. Meso-tetraphenyl porphyrin (H2TPP) and Octaethyl porphyrin (H2OEP) are the porphyrin model compounds and, 4’-Bis-(2-pyren-1-yl-...

Hydrogen bond interactions between acetone and supercritical water are investigated using a combined and sequential Monte Carlo/quantum mechanics (S-MC/QM) approach. Simulation results show a dominant presence of configurations with one hydrogen bond for different supercritical states, indicating that this specific interaction plays an important role on the solvation properties of acetone in su...

The kinetics of nitromethane, nitroethane and 1-nitropropane decomposition and oxidation in supercritical water near the critical point has been studied in a flow reactor. The reaction rate constants have been calculated on the assumption of the first order reaction. The pressure varied over a wide range produced strong effect on the rate of the nitrocompounds decomposition in supercritical wat...

This paper summarizes specific features of supercritical hydrothermal synthesis of metal oxide particles. Supercritical water allows control of the crystal phase, morphology, and particle size since the solvent's properties, such as density of water, can be varied with temperature and pressure, both of which can affect the supersaturation and nucleation. In this review, we describe the advantag...

Supercritical fluids have received much attention for analytical and processing applications. In particular, supercritical carbon dioxide has been used to extract relatively non-polar organics from a variety of environmental matrices, and has also been used for chemical processing. While supercritical carbon dioxide is relatively unreactive and is not an efficient solvent for polar organics, su...

Complete mineralization of hazardous organic compounds to innocuous products can be achieved using supercritical water oxidation (SCWO). At typical SCWO process conditions (500 – 650 °C), free radical chemistry has been shown to be the dominant reaction path. Detailed Chemical Kinetic Mechanisms (DCKM), consisting of elementary free-radical reactions, have been used to model the oxidation of a ...

Supercritical water is favorable medium to carry out diverse reactions, specially focusing on “green chemistry” and environmental applications. The intermolecular structure of water due to hydrogen bond, in these conditions, varies and causes changes in its properties and the properties of its solutions. In order to be able to study the behavior of these solutions, to design hydrolysis and oxid...

Hydrogen is an important chemical in many industries and it is expected to become one of the major fuels for energy generation in the future. Unfortunately, hydrogen does not exist in its elemental form in nature and therefore has to be produced from hydrocarbons, hydrogen-containing compounds or water. Above its critical point (374.8C and 22.1MPa), water has lower density and viscosity, and a ...

The dissolution property of the poorly water-soluble drug, flurbiprofen (FP) was improved by a novel supercritical freeze granulation using supercritical carbon dioxide. Supercritical freeze granulation was defined as a production method of the granulated substances by using the dry ice to generate intentionally for the rapid atomization of the supercritical carbon dioxide to the atmospheric pr...

This study investigates the differences between the predictions of various properties of rigid and flexible simple point charge water models at supercritical conditions. Molecular dynamics simulations were conducted for supercritical water in a temperature range of 773-1073 K and densities in the range 115-659 kg/m3. We present thermodynamic data, pair correlation functions, selfdiffusivity, po...