The oxidation of benzene at a lead dioxide electrode which produces predominantly benzoquinone, maleic acid, and carbon dioxide, has been investigated in aqueous NaHSO4 solutions as a function of temperature up to 250~ An increase in the benzene concentration does not increase the concentration of benzoquinone formed at high temperature, which is different from the behavior at 25~ The formation...

Study presents that supercritical methanol has the ability to convert oils/fats consisting of triglycerides and free fatty acids (FFAs) into fatty acid methyl esters through transesterification and methyl esterification, respectively, without any catalyst. This one-step method (Saka process) is simpler process realizing shorter reaction time and higher yield of methyl esters than those of the c...

As the important signal of once-through boiler's water-fuel ratio control, intermediate point temperature of supercritical boiler plays a key role in the decision of steam and water’s boundary, the match of fuel and water, the control of main steam temperature. The condition of its control directly impacts the once-through boiler’s safety and economy running. For an uncertainty model, a good co...

Sonic velocities of geologic fluids, such as volcanic magmas and geothermal fluids, can be as low as 1 m/s. Critical velocities in large rivers can be of the order of 1-10 m/s. Because velocities of fluids moving in these settings can exceed these characteristic velocities, sonic and supersonic gas flow and critical and supercritical shallow-water flow can occur. The importance of the low chara...

Dissolution pressure and nozzle temperature effects on particle size and distribution were investigated for RESS (Rapid Expansion of Supercritical Solution) process. Supercritical CO2 was used as solvent and Ibuprofen was applied as the model component in all runs. The resulting Ibuprofen nano-particles (about 50 nm in optimized runs) were analyzed by SEM and laser diffraction pa...

In this study, moisture content, free fatty acids, peroxide, iodine value, unsaponifiable matter, saponification value, fatty acid composition and tocopherol contents of wheat germ oil obtained by SC-CO2 extraction and cold press technology were investigated. Moisture, free fatty acid (FFA), peroxide value, iodine value, unsaponifiable matter and saponification value of cold pres...

Injection of carbon dioxide in deep saline aquifers is considered as a method of carbon sequestration. The efficiency of this process is dependent on the fluid-fluid and rock-fluid interactions inside the porous media. For instance, the final storage capacity and total amount of capillary-trapped CO2 inside an aquifer are affected by the interfacial tension between the fluids and the contact an...

A set of computer programs and data tables of TTSE method to calculate the transport properties of water and steam has been developed. Its accuracy and computing speed were compared to those widely used in current industrial applications. The computing time was found to be half of the current method in the compressed-water and superheated-steam regions, and one-tenth in the supercritical region...

the presence of pharmaceutical compounds in the environment and waste streams has received lots of attention in recent years due to its adverse effects on the health of different organism. the emerging of these compounds in the environment is a growing concern and recent researches have focused on finding new ways for enhancing the pharmaceutical compound’s removal efficiency in the effluent of...

Supercritical water and methanol have recently drawn much attention in the field of green chemistry. It is crucial to an understanding of supercritical solvents to know their dynamics and to what extent hydrogen (H) bonds persist in these fluids. Here, we show that with femtosecond infrared (IR) laser pulses water and methanol can be heated to temperatures near and above their critical temperat...