We report the results of a series of molecular dynamics simulations of water inside a carbon-slit pore at supercritical conditions. A range of densities corresponding from liquid (0.66gcm;{-3}) to gas environments (0.08gcm;{-3}) at the supercritical temperature of 673K were considered. Our findings are compared with previous studies of liquid water confined in graphene nanochannels at ambient a...

Gasification of organic matter under the conditions supercritical water (T > 374 °C, p 221 bar) is an allothermal, continuous flow process suitable to convert materials with high moisture content (<20 wt.% dry matter) into a combustible gas. The gasification as solvent offers several benefits, particularly omission energy-intensive drying process. reactions are fast, and mean residence ti...

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-...

Recovery of energy from MSW by combustion in Waste-to-Energy (WTE) plants reduces land filling and air/water emissions, and also lessens dependence on fossil fuels for power generation. The objective of this study was to assess the potential of gasification processes as an alternative to the combustion of MSW. Gasification uses a relatively small amount of oxygen or water vapor to convert the o...

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...

In this paper we present the conceptual design for the optimization of FT-diesel production process from switchgrass via gasification of biomass. We propose a limited superstructure where the process starts with the gasification of the biomass. Two different alternatives are evaluated, direct and indirect gasification. The gas obtained is cleaned up and its composition adjusted in terms of the ...

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...

Phytoremediation is an emerging concept for contaminated soil restoration via the use of resilient plants that can absorb contaminants. The harvested biomass be thermochemically converted to energy carriers/chemicals, linking decontamination with biomass-to-energy and aligning circular economy principles. Two thermochemical conversion steps biomass, both used treatment/exploitation, are conside...

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...