Supercritical Carbon Dioxide Reaction & Extraction Systems
Supercritical Fluid Technologies Inc. has manufactured larger scale pilot scale supercritical fluid extraction and reaction systems. These systems incorporate and build upon many of the features found in SFT’s high end bench top systems and facilitate the transition from laboratory scale equipment to pilot production processing systems. These units are typically in the 10-20 Liter scale, fully automated, and offer recycle of the CO2 liquid.
One of our earlier pilot scale SFE systems was designed and built to extract impurities in polymeric lithium batteries. Through feasibility work completed in the SFT Inc. laboratories it was found that the life, chargeability, and strength of lithium batteries was increased when SCF CO2 was used to extract the impurities in the polymer.
A more recent SF pilot plant system was designed and constructed for a major pharmaceutical firm. A simple P&ID flow diagram for this system is shown in the figure below. This system coupled the precise pressure, temperature, and dosing control features of SFT’s high end bench top equipment with a rack mounted, 20 liter extraction vessel that was ASME code rated to 10,000 psi (690 bar) maximum allowable working pressure (MAWP).
The unique physical and chemical properties of carbon dioxide in its supercritical state, namely the extremely low surface tension, low viscosity, high diffusivity, and “tunable” solvent strength, provide utility in a variety of industrial and scientific applications.
A client came to Supercritical Fluid Technologies looking for a new way to do resistive striping and surface deposition of photolithographic polymers. In the microelectronics fabrication industry, non-toxic, environmentally friendly SCF CO2 is being heavily investigated as an alternative agent for device cleaning, drying, and lithographic processing. With the advances in fabrication techniques and materials, microelectronic device features with dimensions below 100 nm are now possible to produce. At the sub-micron scale, the strong surface tension of the aqueous solvents that are currently used often causes pattern collapse during and after wet processing. The introduction of supercritical carbon dioxide to supplant more toxic aqueous solvents, especially in the lithographic steps, eliminates such adverse effects.
For this application, Supercritical Fluid Technologies offered a special vessel configuration incorporating a unique lifting mechanism which provided the capability to rotate the complete vessel 180 degrees to allow the client access to the interior of the vessel for easy installation of components. This unit included a custom dense gas management package to deliver the various resistive stripping solvents in a controlled manner, and an integrated mass flow meter and weigh scale to complete mass balance calculations.