Autoclave based supercritical CO2 systems
Supercritical CO2 systems based on autoclave
Autoclave-based supercritical CO2 systems are used in many industrial and laboratory sectors. They are preferred because their horizontal arrangement allows the introduction of trays with trolleys on which the objects that need to be processed are horizontally positioned. The applications are the most varied: very delicately drying materials wet or immersed in liquid solutions, impregnating materials at high pressure, coloring fabrics and other applications in which the materials are large.
The internal diameter varies from 25 cm (1″) diameter for laboratory systems up to 1.8 m (6′) for industrial systems. The lid is moved manually for small systems or by electric motors in the case of industrial systems. The depth can be greater than 3 m (10′) to allow processing of long elements. The process is completely automatic and the pressures vary according to use.
2700 L autoclave based CO2 system
Wide 3 m ( 9.8'),
Height 3.5 m (11.4'),
Depth 3,5 m (11.4').
Autoclave based supercritical/liquid CO2 processes
Autoclave-based systems are designed for large or irregularly shaped materials that cannot be processed in a conventional extraction basket, as well as for laboratory applications. They serve the aerospace sector and any industry handling large components or structured materials, from small research units to industrial-scale autoclaves.
The working pressure range is 80–150 bar, with most applications running close to 100 bar. The control system integrates the flow rate of liquid and gaseous CO₂, the liquid CO₂ level inside the autoclave, and temperature and pressure monitoring of both phases, including during transitions. Materials can be loaded wet or fully immersed in their own solvent, and the end-of-cycle venting is programmable for up to 8 hours, allowing extremely slow depressurisation for delicate structures.
Processes
- Secagem de aerogel — supercritical replacement of the pore liquid without capillary collapse, the only viable industrial route for monolithic aerogels.
- Ultra cleaning — removal of contaminants at nanometre scale from precision components, without residues or aqueous rinsing.
- Impregnation — CO₂-assisted penetration of active compounds into porous substrates such as wood, polymers or composites.
- Waterless dyeing — dispersion of dyes in supercritical CO₂ for textiles, with no water and no effluent, at the frontier of the blue economy.
- Sterilisation — treatment of heat-sensitive materials and medical devices at moderate temperature.
- Any other process requiring horizontal loading — long, flat or bulky parts that must be introduced and supported horizontally inside the vessel.