Supercritical Fluid Technologies employs various types of pumping packages for their SFE units. Our analytical scale SFT-110 and SFT-110XW SFE units employ electrically driven pulseless pumps similar to traditional HPLC technology. However, the pump cools the liquid CO2 to 0 degrees Celsius using a thermo electric cooling mechanism (Peltier cooling) which allows efficient pumping of the liquid CO2 up to process pressures. Currently under development are larger versions of these liquid CO2 pumps that can pump liquid CO2 to 10,000 psi (689 bar) at 250ml/min, 500ml/min, and 1000ml/min respectively. Look for these pump packages in mid 2012.
For the SFT-150, SFT-250, SFT-NPX-10 and larger pilot and commercial extraction units where large flow rates are needed, we currently employ a pneumatic air-driven pump. A special fluid heat exchanger is used to cool the liquid CO2 down to the 0 degrees Celsius range to allow for efficient pumping. The CO2 liquid is then delivered to the pump where the pumping package acts very much like a booster pump where the delivery pressure of the liquid CO2 is increased to the meet the application need. An air compressor is typically specified with these larger units such as an Ingersoll-Rand, Model 1240: Two Stage Air Compressor, HP Rating 5.0 HP, Air Delivery 15 Cubic Feet per Minute, Maximum Pressure 175 PSI, Phase Three, Voltage Rating 230/460 Volts, 50 Hz, Current Rating 15.3 Amperes, Tank Capacity 80 Gallons, Tank Type Vertical, Oil Capacity 32 Ounces, Receiver 80V, Height 67 Inches, Length 32 Inches, Width 24 Inches, NPT Outlet (F) 1/2 Inch. The key specification is 110 psi, 15 SLPM flow.