Process and equipment for drying a polymeric aerogel in the presence of a supercritical fluid
US5962539A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 6, 1998 |
| Grant date | Oct 5, 1999 |
| Priority date | — |
| Expiry date | May 6, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P20/54
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A process for obtaining an aerogel from a polymeric material that is in the form a sol-gel in an organic solvent, by exchanging the organic solvent for a fluid having a critical temperature below a temperature of polymer decomposition, and supercritically drying the fluid/sol-gel. The process is carried out in a semi-continuous mode that includes the steps of contacting the initial sol-gel with a stream of the fluid at different pressures and temperatures through n+1 pressure vessels A.sub.0 to A.sub.n that each have an inlet for fluid VI.sub.i and an outlet for effluent VO.sub.i wherein the n+1 pressure vessels are operated dependently on each other through a joint fluid supply system and a joint effluent treatment system so that the respective product in each of the pressure vessels A.sub.0 to A.sub.n is submitted to the fluid in successive steps with pressure and temperature following a curve that never cuts the vaporization curve in the pressure-temperature diagram of FIG. 1.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.