A carbon nanotube (CNT) is a miniature cylindrical carbon structure that has hexagonalgraphite molecules attached at the edges. Nanotubes look like a powder or black soot, but they'reactually rolled-up sheets of graphene that form hollow strands with walls that are only one atom thick.Carbon nanotube has been one of the most actively explored materials in recent year(s) due to...

An apparatus for extracting organic compounds from soils, sands, and other solid matrix materials utilizes water at subcritical temperature and pressure as a solvent. The apparatus, called subcritical water extractor (SCWE), is a prototype of subsystems of future instrumentation systems to be used in searching for organic compounds as signs of past or present life on Mars. An aqueous solution g...

When liquid or supercritical CO2 is mixed with an aqueous slurry of finely pulverized (1-20 microm) limestone (CaCO3) in a high-pressure reactor, a macroemulsion is formed consisting of droplets of CO2 coated with a sheath of CaCO3 particles dispersed in water. The coated droplets are called globules. Depending on the globule diameter and the CaCO3 sheath thickness, the globules sink to the bot...

INTRODUCTION From the stand of the protection of the environment, the development of environmentally benign process using chemical fixation of CO2, which is one of the greenhouse-effect gases, has been drawing much interest in industrial chemistry, because there are a lot of possibilities that carbon dioxide can be used as a safe and cheap C1 component to produce useful organic compounds. Howev...

Supercritical fluid chromatography (SFC) may be defined as a form of chromatography in which the mobile phase is subjected to pressures and temperatures near or above the critical point for the purpose of enhancing the mobile phase solvating power. During its relatively short existence, supercritical fluid chromatography (SFC) has become an attractive alternative to GC and LC in certain industr...

Geologic sequestration in depleted oil reservoirs, saline aquifers, etc. has been proposed as an effective way to stabilize the concentration of CO2 in the atmosphere and thus mitigate its effect on global climate change. We have developed a massively parallel 3-D reservoir simulator PFLOTRAN for modeling supercritical CO2 sequestration in geologic formations based on continuum scale mass and e...

Supercritical CO2 extraction of the pigments from Bixa orellana seeds was carried out in a flow apparatus at a pressure of 200 bar and a temperature of 40 oC at two fluid flow rates (0.67g/min and 1.12g/min). The efficiency of the extraction was low (only about 1% of the pigment was extracted). The increase in flow rate led to a decrease in pigment recovery. A large increase in recovery (from 1...

Wettability plays a major role in subsurface fluid migration, however little empirical evidence besides qualitative relative permeability data in this context is known about the characteristics of carbon dioxide (CO2). Core analysts use several methods combined for use in the oil industry, including the USBM (U.S. Bureau of Mines) method and Amott test, supported visually by images from an envi...

One nanometre wide carbon nanoreactors are utilised as the reaction vessel for catalytic chemical reactions on a preparative scale. Sub-nanometre ruthenium catalytic particles which are encapsulated solely within single-walled carbon nanotubes offering a unique reaction environment are shown to be active when embedded in a supercritical CO2 continuous flow reactor. A range of hydrogenation reac...