We determine the second and third virial coefficients B2 and B3 for the Gaussian charge polarizable model (GCPM) as a function of temperature over the range 210-723 K. The overlap sampling implementation of Mayer sampling molecular simulation is applied to calculate the values, obtaining results to a precision that ranges from 0.1% for B2 to an average of 1% for B3. These calculated values comp...

Supercritical water oxidation provides a powerful means to transform toxic organic materials into simple, relatively inert oxides. Over the past decade, our understanding of the fundamental chemistry of this process has increased markedly. Many fascinating research papers are appearing from laboratories around the world, on the use of the technique for the decomposition of a variety of organic ...

Techniques involving supercritical carbon dioxide have been successfully used for the formation of drug particles with controlled size distributions. However, these processes show some limitations, particularly in processing aqueous solutions. A diagram walking algorithm based on available experimental data was developed to evaluate the effect of ethanol on the efficiency of water removal proce...

The state of aggregation of water dissolved in supercritical carbon dioxide has been investigated under isobaric heating (T=40-340°C, P=250 bar) using infrared absorption and Raman scattering spectroscopies. Quantitative analysis of experimental spectra has shown that below 100°C, water exists only in its monomeric form (solitary water surrounded by CO2 molecules) whereas H-bonded species, name...

The site-selective H/D exchange reaction of phenol in sub- and supercritical water is studied without added catalysts. In subcritical water in equilibrium with steam at 210-240 degrees C, the H/D exchange proceeds both at the ortho and para sites in the phenyl ring, with no exchange observed at the meta site. The pseudo-first-order rate constants are of the order of 10(-4) s(-1); 50% larger for...

The site-selective H/D exchange reaction of phenol in sub-and supercritical water is studied without added catalysts. In subcritical water in equilibrium with steam at 210–240 °C, the H/D exchange proceeds both at the ortho and para sites in the phenyl ring, with no exchange observed at the meta site. The pseudo-first-order rate constants are of the order of 10 Ϫ4 s Ϫ1 ; 50% larger for the orth...

In this work, our objective was to examine methods for processing cashew nut shell liquid and cashew shell with carbon dioxide and water. Supercritical CO2 was applied for extraction of split cashew shells and near-critical water was applied for reaction of the cashew shell material. In the extractions, it was found that a pressurization-depressurization step that was approximately 1 h gave ext...

Simulations of simple solutes (charged and uncharged spheres) in model water have been performed in order to elucidate aspects of solvation in water at ambient and supercritical states. The variation of solvation entropy as a function of solute charge has been used to investigate hydrophobic and hydrophilic ordering and the structure-making and structurebreaking effects of ions. Simulations wit...

The present study investigates the potential conversion of sugarcane into ethanol and synthetic natural gas. The considered conversion path consists in combining ethanol first and second generation ethanol production plant with a catalytic supercritical water gasification system. The main steps of the ethanol conversion consider fermentation of sugars (1G) and enzymatic hydrolysis of bagasse (2...