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...

Numerical studies have been carried out to investigate supercritical flow instabilities in a CO2 natural circulation loop. For the steady state and dynamic analyses of the loop under supercritical conditions, a single-channel, one-dimensional model is developed. In this model, equations for the conservation of mass, momentum and energy are discretized using an implicit finite difference scheme....

The axial dispersion coefficient of hexachlorobenzene in supercritical carbon dioxide is investigated in a fixed-bed packed with glass beads. The on-line chromatographic pulse-response experiment is used in order to study the dynamics of a packed column under supercritical conditions. The radial dispersion is assumed negligible because of the packed column geometry. To estimate the axial disper...

enzyme efficiency was investigated in the lipase-catalyzed hydrolysis of canola oil in supercritical carbon dioxide (scco2). immobilized lipase from mucor miehie (lipozyme im) was used as the catalyst and the results showed that enzyme efficiency dropped at high pressures indicating a possible change in enzyme microstructure. therefore, scanning electron microscopy (sem) was used as a supplemen...

The CO2-brine dissolution homogenizes the distribution of residual CO2 and reduces the leakage risk in the saline aquifer. As a key parameter to immobilize the free CO2, the dissolution rate of CO2-brine could be accelerated through mechanisms like diffusion and dispersion, which are affected by the subsurface condition, pore structure, and background hydrological flow. This study contributed t...

The glycerol desorption from the ion exchange and adsorbent resin Purolite PD206 was studied using conventional and supercritical fluids techniques. Untreated biodiesel was purified by dry washing using the resin and, after purification, the glycerol desorption was carry out using three diferent solvents: absolute ethanol under atmospheric conditions at different mass flows (10 and 30 g/min), o...

Two different types of standing waves (SW0 and SWπ) can appear instead of spiral vortices from a supercritical Hopf bifurcation in counter-rotating Taylor-Couette flow for sufficiently small aspect ratios [1,2]. The bifurcation sequence from basic flow to spiral vortices via SW0 can include modulated waves, homoclinic bifurcations, and hysteresis as a consequence of broken translational invaria...