Monthly Archives: November 2011

Why do the SFT-150 and SFT-250 require a chiller / recirculator?

The chiller is used to transfer heat away from the pump head. Cooling the pump head ensures that only liquid carbon dioxide reaches the pump. This is important because the unit cannot pump gaseous carbon dioxide. The chiller essentially does … Continue reading

Posted in FAQ |

Does the liquid carbon dioxide pump shut off during a static extraction?

Yes, the pump will fill/pressurize the extraction vessel up to the set point. If there is no flow of material out of the vessel, the pump will shut off. As soon as the variable restrictor is opened, dissolved materials (analyte) … Continue reading

Posted in FAQ |

How does SFT’s carbon dioxide pump work?

Various types of pumps can be used for supercritical fluid applications. For medium to large volume processes, a pneumatic booster pump is most often used. A diaphragm pushes against a piston to compress the liquid carbon dioxide to a set … Continue reading

Posted in FAQ |

Why is carbon dioxide most often the media of choice for SFR?

The properties which make supercritical carbon dioxide an attractive solvent for extraction also apply to its use as a medium for reaction chemistry. A fluid’s most important physical and transport properties that influence the kinetics of a chemical reaction are … Continue reading

Posted in FAQ |

Why is carbon dioxide used most often in SFE?

Supercritical fluid extraction has emerged as an attractive separation technique for the food and pharmaceutical industries due to a growing demand for “natural” processes that do not introduce any residual organic chemicals. Supercritical carbon dioxideis by far the most commonly … Continue reading

Posted in FAQ |

How do supercritical fluids work?

When a gas such a carbon dioxide is compressed and heated, its physical properties change and it is referred to as a supercritical fluid. Under these conditions, it has the solvating power of a liquid and the diffusivity of a … Continue reading

Posted in FAQ |